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外文文献翻译译稿和原文

外文文献翻译译稿1卡尔曼滤波的一个典型实例是从一组有限的，包含噪声的，通过对物体位置的观察序列（可能有偏差）预测出物体的位置的坐标及速度。

在很多工程应用（如雷达、计算机视觉）中都可以找到它的身影。

同时，卡尔曼滤波也是控制理论以及控制系统工程中的一个重要课题。

例如，对于雷达来说，人们感兴趣的是其能够跟踪目标。

但目标的位置、速度、加速度的测量值往往在任何时候都有噪声。

卡尔曼滤波利用目标的动态信息，设法去掉噪声的影响，得到一个关于目标位置的好的估计。

这个估计可以是对当前目标位置的估计（滤波），也可以是对于将来位置的估计（预测），也可以是对过去位置的估计（插值或平滑）。

命名[编辑]这种滤波方法以它的发明者鲁道夫.E.卡尔曼（Rudolph E. Kalman）命名，但是根据文献可知实际上Peter Swerling在更早之前就提出了一种类似的算法。

斯坦利。

施密特（Stanley Schmidt）首次实现了卡尔曼滤波器。

卡尔曼在NASA埃姆斯研究中心访问时，发现他的方法对于解决阿波罗计划的轨道预测很有用，后来阿波罗飞船的导航电脑便使用了这种滤波器。

关于这种滤波器的论文由Swerling（1958）、Kalman (1960)与Kalman and Bucy（1961）发表。

目前，卡尔曼滤波已经有很多不同的实现。

卡尔曼最初提出的形式现在一般称为简单卡尔曼滤波器。

除此以外，还有施密特扩展滤波器、信息滤波器以及很多Bierman, Thornton开发的平方根滤波器的变种。

也许最常见的卡尔曼滤波器是锁相环，它在收音机、计算机和几乎任何视频或通讯设备中广泛存在。

以下的讨论需要线性代数以及概率论的一般知识。

卡尔曼滤波建立在线性代数和隐马尔可夫模型（hidden Markov model）上。

其基本动态系统可以用一个马尔可夫链表示，该马尔可夫链建立在一个被高斯噪声（即正态分布的噪声）干扰的线性算子上的。

系统的状态可以用一个元素为实数的向量表示。

外文翻译及原文

Pyrolysis of oil sludge first by thermogravimetry/mass spectroscopy (TG/MS) and then in a horizontal quartz reactor with an electrical laboratory furnace under different pyrolysis conditions was carried out. The influence of heating rate from 5 to 20 °Camin-1, final pyrolysis temperature from 400 to 700 °C, various interval holding stage, and catalyst on the products were investigated in detail. The TG/MS results show that pyrolysis reaction of oil sludge starts at a low temperature of about 200 °C, and the maximum evolution rate is observed between the temperatures of 350-500 °C. A higher final pyrolysis temperature, an interval holding stage, and adding catalyst can promote the pyrolysis conversion (in terms of less solid residue production). In all parameters, an interval holding stage for 20 min near the peak temperature of 400 °C can enhance the yield of oil and improve its quality. Three additives used in this work as catalysts do not improve oil product quality markedly in spite of increasing pyrolysis conversion greatly.油泥的裂解首先通过热重/质谱分析（TG / MS），然后在水平石英反应器中具有不同热解条件下的电气实验室炉进行。

自动化专业-外文文献-英文文献-外文翻译-plc方面

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外文翻译英语原文编号01

Vol.25 No.2 PANG Chaoming et al: Methods of Modifying the Brittle (156)DOI 10.1007/s11595-010-1156-yMethods of Modifying the Brittle Behavior ofCementitious CompositesPANG Chaoming1, SUN Wei1, LEUNG Christopher KY2(1.College of Materials Science and Engineering, Southeast University, Jiangsu Key laboratory of Construction Materials, Nanjing 211189,China;2. Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong, China SAR)Abstract: We put forward effective methods of increasing the tensile strain of cementitiouscomposites with 2% PVA fiber and high fly ash content. The test results show that curing condition hasa significantly effect on the tensile performance. It is approved that the specimens incorporated ap-propriate volume fraction rubber powder and lightweight aggregate greatly increase the tensile strain ofcomposites at medium-term age, but indefinitely at long-term age. To a certain extent, EVA can limitedlyenhance the tensile performance of comentitious composites owing to the formation of polymer membraneand the hindered hydration of cement.Key word: high-ductility cementitious composites (HDCC); tensile properties; high content offly ash; rubber powder; light aggregate; ethylene vinyl alcohol latex powder1 IntroductionCementitious composites are widely used as the majority of structural materials. However, cementitious composites are limited to some special projects due to the inherently brittle behavior. Most efforts have been made to modify the brittle behavior of cementitious composites all along. As a result, the fiber reinforced cementitious composites (FRCC) occurred. In comparison to plain concrete, FRC usually deteriorates the tensile or bending properties by the formation of several cracks and a main crack. In the past two decades, Li, Leung and Wu etc[1-3] investigated the bridging stress of fiber and proposed the theory for high-ductility cementitious composites (here-after abbreviated as HDCCs) or pseudo ductility cemen-titious composites or pseudo strain hardening cementi-tious composites, based on the two nondimensionalized parameters energy absorption rate and normalized flaw size. It has been demonstrated that the ductility behaviors of brittle materials can be achieved by multiple cracks in steady state along the length of the specimen and behave pseudo strain hardening (abbr. PSH). Hereafter, the theories for PSH in the cementitious composites were gradually developed by Li and his co-workers, and the particular theory for “composite design”, based on the micro mechanics parameter, by emphasizing the proper integrant materials and interface was proposed[4,5]. The cementitious composite with high tensile strain capacity of 3%-6%, whose strain capacity is far outperforming conventional cementitious composites, was achieved[6].Recently increasing researchers are interesting to the new type of fiber reinforced cementitious composite. However, it is not easy to achieve PSH in discontinuous random fiber reinforced. Strain due to a little deviation of raw materials occur even if the well-known same mixture proportion of ECC is used due to a little deviation of raw materials. Meanwhile, the design method of existing theory depend on known experimental micro mechanics parameters, such as the fracture toughness, fiber content, fiber strength, fiber distribution, the bridging stress and interface properties between fiber matrix, etc. Moreover, it is very difficult to achieve the accurate fiber distribu-tion and bridging stress due to the randomization and inhomogeneity of the distribution of fiber in composites. But the micromechanical parameters and the ductile be-havior is strongly affected by the bridging stress governed by fiber debonding, fiber bending, fiber rupture, matrix spalling and their coupling[2].The focus in the current study is to discover the ef-ficacious methods to increase the tensile strain of HDCC. It is well know that curing conditions have a significantly©Wuhan University of Technology and Springer-Verlag Berlin Heidelberg 2010 (Received: Jan. 6, 2009; Accepted: Oct. 16, 2009)PANG Chaoming(庞超明): Ph D candidate; E-mail: pangchao@seu. edu. cnJournal of Wuhan University of Technology-Mater. Sci. Ed. Feb.2010157conditions were used for comparison, considering that the structures in practice project are often exposed to different environment and different curing condition are usually applied according to the lab environment in the different researches. For the brittle cementitious com-posites, the matrix cracking strength, which is determined by the matrix toughness and the largest crack or flaw in the stress section of specimen provided that the matrix cracking is controlled by fracture process, does not de-crease unlimitedly but reaches a lower bound at steady state cracking stress with the growing flaw size [7]. Moreover, the discontinuous pre-existing flaw or mi-cro-voids may relax the crack-tip stress triaxiality, dif-fuse the intensity of crack-tip stress singularity and consume more energy. To ensure the formation of multiple cracks, it is desirable to introduce a rtificial flaws in the matrix to reduce its crack tip toughness and increase the crack size due to energy absorption of flaw [8]. Therefore, different materials, such as rubber powder and fine lightweight aggregate, were added to the composites to increase the strain capacity.2 ExperimentalSpecial green island brand P·II 52.5 cement was used. The range of particle size of fly ash is mainly 2-10 μm, and the active index of compressive strength at 7 days, 28 days and 90 days are the 86%, 84% and 96% respectively followed by ASTM C311-04. Polyvinyl alcohol fiber (abbr. PVAF) produced by Japan Kuraray Limited Corporation was used, and its density, length, diameter were 1.3 g/cm 3, 12 mm, 38 μm respectively,also its elastic modulus and rate of elongation is 33 GPaand 6.5% respectively.The particle size of silica fume, silica filler and silica sand used is 1-20 μm, 1-15 μm and 50-200 μm respec-tively. ADVA105 superplastics admixture (abbr. Sp) was ％produced by Grace Co.LTD and its solid content is 23. SP4000 (abbr. SP4), which is ethylene vinyl alcohol (abbr. EVA) latex powder and is produced by Japan Kuraray Trading Co.LTD, was used in this study. The particle size of lightweight aggregate (abbr. LA) is between 1 mm and 3 mm, whose specific density is 1 500 kg/m 3, and the loose volume weight is about 780 kg/m 3. Rubber pow-der with the particle size of 0.4 mm was also used.The specimen was demoulded 24 hours after casting, where the temperature and relative humidity was about 20±2 ℃ and (60±5)％ respectively, then cured in water at curing room , where the temperature is 27 ℃ (ac-cording to the BS standard). The nominal sizes used for tensile performance and compressive performance are about 350×50×15 mm and 40×40×40 mm respec-tively. The dimensions of the specimen were accurately measured by vernier caliper and all the specimens were polished to smooth surface before testing to obtain ac-curate experimental results, and at least three specimens were tested at each age.The tensile performance was tested under the dis-placement control in the MTS810-25 kN materials test-ing system with the displacement rate of 0.15 mm/min. Linear variable displacement transducer was used to measure the displacement at the gage length of 150 mm for the more accuracy purpose. The first crack strain εfc , the peak strain εp and the maximum strain εm repre-sent to the strain corresponding to the first crack stress σTc when the first crack occurred, peak stress σTp when the stress reaches the peak, and the strain when the stress descends up to 90% σTp , respectively.3 Results3.1 Effect of curing conditions on me-chanical properties of HDCCAccording to previous work, two mix proportions shown in Table 1 were used, i e , SP4 and W1 with high volume fraction fly ash and low ratio of water to binder (cement and fly ash). Table 1 Mix proportion in mass of HDCC No. cement FA SP4 sand water Sp PVAF SP4 1 3.9 0.1 1.0 1.1 0.022 0.090 W1 1 4.0 0 1.0 1.0 0.023 0.096For the purpose of comparing the effect of different curing condition on the tensile performance, four types of curing conditions were applied in mixture SP4 as fol-lowing: full dry curing in room temperature condition after demoulded, which corresponds to symbol D in the denominated title in Table 2, dry curing in room tem-perature condition after 3-day curing in water corre-sponding to symbol W3D, dry curing in room tempera-ture condition after 7-day water curing corresponding to symbol W7D, and 28-day water curing corresponding to symbol W. The only two types of curing conditions wereused in mixture W1: dry curing in room temperature condition after 7 days water curing and full water curing. Table 2 list the test results of the tensile strength and strain and compressive strength on different curing con-ditions at the age of 7-day and 28-day.Vol.25 No.2 PANG Chaoming et al : Methods of Modifying the Brittle …1583.2 Effect of rubber powder on mechanic-al properties of HDCCThe specimen without rubber powder is regarded as control specimen, and two mixtures of HDCCs with the rubber powder were prepared. SR7 and SR11 represent for HDCC of the volume fraction of 7% and 11%, re-spectively. For estimating the long-term performance, the accelerated curing method was conducted, that is, after cured in water for 7 days, at least three specimens were put to the heat curing room for 72 hours, where the temperature and relative humidity are 80 ℃％and 95respectively, the mechanical performance was measured after being cooled down in the room temperature condi-tion. The mix proportion used and test results are sum-marized in Table 3, Table 4 respectively. Heat curing corresponds to symbol HC. Fig.1 shows the tensile stress versus strain curves of SR7 and SR11 at 28 days.3.3 Effect of lightweight aggregate onmechanical properties of HDCC For the purpose of researching the effect of light-weight aggregate on the tensile strain of HDCC with highflyash content, the volume fraction of 3.5% was incor-porated into the mixture, and the mix proportion was listed in Table 5. The specimen FA3 and FA3LA corre-spond to control specimen and specimen with lightweight aggregate, respectively.The test results are shown in Table 6. The condition of heat curing is the same as mentioned above. Fig.2(a) and Fig.2(b) showed the typical stress vs strain curve of FA3 and FA3LA3.5 at different age: 7 days, 28 days and heat curing 3 days.Table 2 Test results of HDCC on different curing conditionsSP4D SP4W3D SP4W7D SP4W W1 7-day 28-day 7-day 28-day 28-day 90-day 7-day 28-day W7 W28 W7DσTfc /MPa 2.68 2.36 2.91 2.54 3.26 3.28 2.70 3.36 2.76 3.65 3.62 εfc /% 0.080 0.069 0.075 0.096 0.080 0.089 0.119 0.060 0.088 0.047 0.128 σTp /MPa 3.30 3.39 3.76 3.14 4.07 3.62 3.17 4.02 3.27 3.81 4.69εp /% 1.53 3.95 2.69 2.56 2.82 2.58 2.78 0.77 1.050.35 2.94 εm /% 1.69 4.28 2.80 2.79 3.54 2.66 2.97 1.81 1.360.54 3.39 σcom /MPa 22.8 27.2 — — — — 23.4 36.0 35.8 58.9 — Table 3 Mix proportion in mass of HDCC with different volume fraction of rubber powder No. Cement FA Filler Sand Rubber Water Sp PVAFControl 1 1.50 0.25 1.00 0 0.63 0.015 0.057 SR7 1 1.50 0.25 0.65 0.163 0.58 0.020 0.055 SR11 1 1.50 0.25 0.40 0.263 0.58 0.020 0.055 Table 4 Test results of HDCCs with different volume fraction of rubber powderControl SR7 SR117-day 28-day 90-day 7-day 28-day HC 7-day 28-day HCσTfc /MPa 3.58 4.61 3.81 2.31 2.60 3.63 2.19 2.31 3.28 εfc /% 0.050 0.042 0.027 0.036 0.022 0.039 0.034 0.051 0.041 σTp/MPa 4.30 5.05 4.53 2.49 3.00 3.81 2.72 3.18 3.57 εp /% 1.33 0.84 0.29 0.31 0.58 0.16 1.04 2.15 0.20 εm/% 1.59 0.98 0.39 0.54 1.07 0.71 1.40 2.49 0.34 σcom /MPa 49.6 66.2 — 29.7 35.7 40.5 24.8 31.4 37.0 Table 5 Mix proportion in mass No. Cement FA LA Sand Water Sp PVAF FA3 1 3 — 1 1 0.025 0.056 FA3LA 1 3 0.16 1 1 0.028 0.056 Table 6 Test results of HDCCs with or without lightweightaggregate FA3 FA3LA 7 d 28 d 90 d HC 7 d 28 d 90 d HCσTfc /MPa 1.42 2.68 3.60 4.38 2.86 3.15 3.25 6.42εfc /% 0.015 0.044 0.031 0.022 0.025 0.045 0.040 0.037 σTp /MPa 2.91 3.46 4.86 4.86 2.86 3.91 3.92 6.49εp /% 0.04 0.58 0.29 0.08 0.03 1.96 0.23 0.04 εm /% 1.16 0.96 0.66 0.31 1.40 2.07 0.54 0.38 σcom/MPa 21.5 44.7 69.5— 19.0 44.2 74.8 —Journal of Wuhan University of Technology-Mater. Sci. Ed. Feb.20101593.4 Effect of EVA powder on mechanicalproperties of HDCCA series of HDCCs specimens with or without EVA powder were also prepared, cured and tested at prescribed age followed by the test procedure. The condition of heat curing is also the same as mentioned above. The mix proportion used is listed in Table 7, and test results of tensile properties are presented in Table 8 and Fig.2(c) respectively. S is the control specimen, and SS4 is representative for HDCC with EVA powder.4 Discussion It can be concluded that the curing conditions have a great effect on the tensile properties from Table 1 and Table 2. The tensile properties exhibit a great difference at 28 days due to different curing condition for mixture SP4 and mixture W1. The HDCC cured in water per-forms better than that in room temperature condition atthe early age, however, as the age increases, the tensileperformance of HDCCs cured in room temperature condition shows an increasing tendency while that curedin the water decreases. The tensile strain of specimensthat of W3D is similar to that of W7D at 28 days, whichtest results also show the ultimate tensile strength has not direct relationship with the tensile strain, and high tensile strain do not mean low tensile strength, and vice versa . That can be explained as follows: curing condi-tion plays a significant influence on microstructure and macroscopical performance of cementitious composites. For fiber reinforced cementitious composites, there exists a distinctive layer of interface zone about 30-50 μm away from the fiber surface [9]. Also the interface will strongly influence the toughness of the compositesand frictional bond [10]. Generally the interface zone is considerable weaker than the matrix due to the large calcium hydroxide crystals and higher porosity for the FRCCs with steel fiber or polypropylene fiber [9], but thePVA fiber is a special organic fiber to the cementitiouscomposites. The majority of fibers used to the cementi-tious composites, such as steel fiber, polypropylenefiber,etc , will not react with the hydration products of cement, but the investigations by Akers show that [11], the PVA fiber performs surprisingly high chemical bonding between the PVA fiber and cement hydrationproducts due to the strong hydrophilic characteristic or hydrogen intermolecular bond induced by the hydroxyl groups, and as the age increase, while there are no evi-dent change in fiber properties, the bonding strengthbetween fiber and cement-based matrix will increase due to an increase in interface bond with age. The re-searches by Kanda T etc also shows that the apparent chemical bonding between PVA fiber and cement ma-，trix independent of the water-to cement ratio of matrix, is relatively stable and up to 30-40 MPa, but the value of friction bond, affected by water to cement ratio, is be-tween 2.2 MPa to 4.4 MPa when the water to cementvaries from 0.62 to 0.27[12]. Through the investigation by Li and his co-workers [3], only the FRCC with the appropriate fracture toughness of matrix and frictional Table 7 Mix proportion with or without EVA in mass No. Cement FA SF SP4 Sand Water Sp PVAF S 1 3.85 0.1 — 1 1.21 0.033 0.096 SS4 1 3.60 0.1 0.1 1 1.21 0.032 0.096 Table 8 Test results of HDCCs with or without EVAS SS47 d 28 d HC 7 d 28 d HCσTfc /MPa 1.15 3.32 4.37 1.86 3.14 3.89 εfc/% 0.021 0.067 0.029 0.057 0.086 0.049 σTp /MPa 1.94 3.43 4.90 2.03 3.42 4.75 εp /% 0.20 1.18 0.33 0.49 1.24 0.60εm /% 0.54 1.63 0.40 1.55 1.73 0.74 σcom /MPa 13.0 33.5 — 13.0 35.4 — (a) FA3 (b) FA3LA (c) S and SS4Fig.2 Stresses vs. Strain curves of FA3, FA3LA, S and SS4 at different ageVol.25 No.2 PANG Chaoming et al: Methods of Modifying the Brittle (160)and high strain capacity of FRCC can dominantly be achieved by using PVA fiber, and the interfacial fric-tional stress for FRCC with PSH behavior show the relative definite requirement and shall preferably be between 0.8 to 2.0 MPa[13], and the value can be achieved by applying oil agent[14]. In the present study, the PVA fiber, which had been coated with the oiling agent by Japan Kuraray Co. LTD, was employed. Ow-ing to low water to binder ratio and high content of fly ash (W/B＝0.20, FA/C＝4.0), and the specimens were kept only for 0-7 days in water and then longer than 20 days cured in room temperature condition, where there is no enough water for cement hydration, therefore they exhibit relative lower hydration degree and larger shrinkage than those cured in the water in all time. The lower hydration degree and larger shrinkage result in relatively lower frictional bond and weaker interface between PVA fiber and matrix[15]. Therefore, the former forms relatively looser structure and satisfies the re-quirement of low interfacial frictional stress, therefore performs better in strain hardening. Also the failure pat-tern of fiber rupture can be observed in testing process of the latter.In general, the definite range of interfacial fric-tional stress for achieving PSH behavior of FRCC, lower ratio of cement to binder, high fly ash content and PVA fiber properties contribute to the effect of curing condition on the tensile behavior.It can be deduced from Table 4, Table 6, Fig.1 and Fig.2 that the tensile strength of HDCC with rubber powder or light aggregate keep on growing, while the tensile strain also increases as the age increases from 7 days to 28 days, then decreased as the age continually grows up to 90 days or when heat curing was applied. That is because the fiber/matrix bond strength should saturate in a duration of less than 14-28 days, and ma-ture much earlier than matrix properties in cementi-tious[16]. But the high content of fly ash will considera-bly lower the chemical bond and delay the mature due to diluting the metal cation concentration on the fiber surface at early age and as a result the strain increases from 7 days to 28 days[17]. But the friction strength and the facture toughness of matrix continue to develop as age increase to 28 days as the second hydration of fly ash continually develop due to activity effect of fly ash under high temperature or at long age. When the imbal-ance of develop rate occurs, the strain decreases with the continual increasing age.From Table 4 and Table 6, not all the specimens show better tensile performance than the control specimen, only the tensile strain of the specimens with 11% volume fraction rubber powder or 3.5% light-weight aggregate increase comparing to the control specimen at 28 days. The specimens FA3 and FA3LA rapidly reach ultimate strength then crack, and only few cracks develop due to the high fracture toughness of matrix and the low friction between matrix and PVA fiber at 7 days, but the specimen can still maintain the considerable strain after cracking owing to fiber gradu-ally being pulled out. And the SR7 also shows the similar tendency at 28 days. It is possible that the frac-ture toughness of matrix develops faster than the chemical bond and the frictional bond due to the low ratio of water to binder and high content fly ash. However, the specimen with the 11% volume fraction rubber pow-der reaches 2.15% in comparison with only 0.84% for the corresponding control specimen and the ultimate strain of with or without lightweight aggregate varies from 1.96% to 0.58%. The similar test results, i e, pre-existing flaw or micro-voids can modify the brittle behavior of HDCC, were observed in the reference[8] as the pre-existing flaw can relax the crack-tip triaxiality, diffuse the intensity of crack-tip stress and consume more energy, and the lager flaw will not influence the cracking strength but reached a lower bound at a steady state of cracking stress.Table 8 and Fig.2 present that the EVA latex powder show a little positive effect on the tensile strain at different age. It is possible that the EVA as a polymer can form a layer polymer membrane, which hinders the hydration of cementitious materials, but the membrane only influences a little hydration process owing to the lower content, about 1% volume fraction, in compos-ites.In summary, the appropriate fracture toughness of matrix and frictional bond between fiber and matrix is necessary conditions to achieve the PSH behavior or high strain capability. The curing condition emphasize particularly on the influence of friction bond, but the incorporation of rubber powder and lightweight lay particular stress on the fracture toughness of matrix. However the incorporation of rubber powder and lightweight aggregate lower the fracture toughness of matrix and facilitate the crack of matrix, which will possibly lower the effect of curing condition on the tensile properties.Journal of Wuhan University of Technology-Mater. Sci. Ed. Feb.2010 1615 ConclusionsSome methods to modifying the brittle behavior of HDCC with high content fly ash are proposed. It is undoubted that curing condition will strongly influence the microstructure of cementitious composites. The test results show that curing condition has a significant ef-fect on the tensile strain of HDCC with high content fly ash, and dry curing condition will show the clear trend to increase the tensile strain of HDCC with high content fly ash. Not all the specimens but the specimens with appropriate volume fracture rubber powder and light-weight aggregate greatly enhance the tensile strain of HDCC at medium-term age, but indefinitely at long-term age impossibly because disconnected pre-existing flaw or micro-voids may relax the crack-tip, diffuse the intensity of crack-tip stress and significantly consume energy. To a certain extent, EVA can enhance the tensile performance of HDCC owing to the hindered hydration of cement based materials as a result of the formation of polymer membrane. But it is possible that the incorporation of rubber powder and lightweight will lower the effect of curing condition on the tensile per-formance.It also experimentally demonstrates that some specimens rapidly reach ultimate strength and crack, but some specimen can still maintain the considerable strain after cracking owing to fiber gradually being pulled out. The tensile stress keeps increasing, but the tensile strain firstly increases then decreases as the age continually grows because of the imbalance of develop rate between bond strength and matrix properties. References[1]LI V C and LEUNG C K Y. Steady-state and MultipleCracking of Short Random Fiber Composites[J]. Journal ofEngineering Mechanics, 1992, 118(11): 2 246-2 264[2]LEUNG C K Y and LI V C. Effect of Fiber Inclination onCrack Bridging Stress in Fiber Reinforced Brittle MatrixComposites[J]. Journal of Mechanical Physics, 1992, 40(6):1 333-1 362[3]LI V C and WU H C. Conditions for PseudoStrain-Hardening in Fiber Reinforced Brittle MatrixComposites[J]. Applied Mechanics Revolution, 1992, 45(8):390-398[4]LI V C, MISHRA D K and WU H C. Matrix Design forPseudo-Strain-Hardening Fiber Reinforced CementitiousComposites[J]. Materials and Structures, 1995, 28: 586-595 [5]KANDA T, LI V C and Member of ASCE. New Micro-mechanics Design Theory for Pseudostrain Hardness Ce-mentitious Composite[J]. Journal of Engineering Me-chanics, 1999, 125(4): 373-381[6]LI V C, WANG S and WU C. Tensile Strain- HardeningBehavior or Polyvinyl Alcohol Engineered CementitiousComposite (PVA-ECC)[J]. ACI Materials Journal, 2001,98(6): 483-492[7]MAESHALL D B, COX B N and EVANS A G. The Mechan-ics of Matrix Cracking in Brittle Matrix Fiber Composites[J].ACTA Metallurgical, 1985, 33(11): 2 013-2 021[8]WANG S and LI V C. Tailoring of Pre-Existing Flaw inECC Matrix for Saturated Strain Hardening[C]. Proceed-ings of the Fifth International Conference on FractureMechanics of Concrete and Concrete Structures. Colorado:Ia-FraMCos, 2004: 1 005-1 012[9]Li V C, WU H C, and CHAN Y W. Interfacial PropertyTailoring for Pseudo Strain-Hardening Cementitious Composites[C]. Advanced Technology on Design and Fabrication of Composite Materials and Structures. Neth-erlands: Kluwer Acad. Publ., 1995: 261-268[10]SUN W, MANDEL J A and SAID Samir. Studies of theProperties of the Fiber-Matrix Interface in Steel Fiber Re-inforced Mortar[J]. ACI Materials Journal, 1987, 84(12):101-109[11]AKERS S A S. Long Term Durability of PVA ReinforcingFibers in a Cement Matrix[J]. The International Journal ofCement Composite and Lightweight Concrete, 1989, 11:79-91[12]KANDA T and LI V C. Interface Property and ApparentStrength of High-Strength Hydrophilic Fiber in CementMatrix[J]. Journal of Materials in Civil Engineering, 1998,10(1): 5-13[13]LI V C and WANG S. Process for Increasing the Ductilityof High Performance Fiber-Reinforced Brittle Matrix Composites and Composites Produced Thereby[P]. US Patent 7169224. 2007-01-30[14]REDON C. Measuring and Modifying Interface Propertiesof PVA Fibers in ECC Matrix[J]. ASCE J. Materials inCivil Engineering, 2001, 13(6): 399-406[15]CHEN H SUN W and PIET S. Interfacial Transition ZoneBetween Aggregate and Paste in Cementitious Composites(II): Mechanism of Formation and Degradation of Interfa-cial Transition Zone Microstructure and Its Influence Factors[J].Journal of the Cement Ceramic Society, 2004, 32(1): 70-80 [16]CHAN Y W and LI V C. Age Effect on the Characteristicsof Fibre/Cement Interfacial Properties[J]. Journal of Ma-terials Science, 1997, 32: 5 287-5 292[17]WANG S and LI V C. Engineered Cementitious Compos-ites with High-Volume Fly Ash[J]. ACI Materials Journal,2007, 104(3): 233-241。

外文翻译--创业板市场

外文文献翻译译文一、外文原文原文：China's Second BoardI. Significance of and events leading to the establishment of a Second BoardOn 31 March 2009 the China Securities Regulatory Commission (CSRC issued Interim Measures on the Administration of Initial Public Offerings and Listings of Shares on the ChiNext [i.e., the Second Board, also called the Growth Enterprise Market] ("Interim Measures"), which came into force on 1 May 2009. This marked the creation by the Shenzhen Stock Exchange of the long-awaited market for venture businesses. As the original plan to establish such a market in 2001 had come to nothing when the dotcom bubble burst, the market's final opening came after a delay of nearly 10 years.Ever since the 1980s, when the Chinese government began to foster the development of science and technology, venture capital has been seen in China as a means of supporting the development of high-tech companies financially. The aim, as can be seen from the name of the 1996 Law of the People's Republic of China on Promoting the Conversion of Scientific and Technological Findings into Productivity ,was to support the commercialization of scientific and technological developments. Venture capital funds developed gradually in the late 1990s, and between then and 2000 it looked increasingly likely that a Second Board would be established. When the CSRC published a draft plan for this in September 2000, the stage was set. However, when the dotcom bubble (and especially the NASDAQ bubble) burst, this plan was shelved. Also, Chinese investors and venture capitalists were probably not quite ready for such a move.As a result, Chinese venture businesses sought to list on overseas markets (a so-called "red chip listing") from the late 1990s. However, as these listings increased, so did the criticism that valuable Chinese assets were being siphoned overseas.On thepolicy front, in 2004 the State Council published Some Opinions on Reform, Opening and Steady Growth of Capital Markets ("the Nine Opinions"), in which the concept of a "multi-tier capital market" was presented for the first time. A first step in this direction was made in the same year, when an SME Board was established as part of the Main Board. Although there appear to have been plans to eventually relax the SME Board's listing requirements, which were the same as those for companies listed on the Main Board, and to make it a market especially for venture businesses, it was decided to establish a separate market (the Second Board) for this purpose and to learn from the experience of the SME Board.As well as being part of the process of creating a multi-tier capital market, the establishment of the Second Board was one of the measures included in the policy document Several Opinions of the General Office of the State Council on Providing Financing Support for Economic Development ("the 30 Financial Measures"), published in December 2008 in response to the global financial crisis and intended as a way of making it easier for SMEs to raise capital.It goes without saying that the creation of the Second Board was also an important development in that it gives private equity funds the opportunity to exit their investments. The absence of such an exit had been a disincentive to such investment, with most funds looking for a red chip listing as a way of exiting their investments. However, with surplus savings at home, the Chinese authorities began to encourage companies to raise capital on the domestic market rather than overseas. This led, in September 2006, to a rule making it more difficult for Chinese venture businesses to list their shares on overseas markets. The corollary of this was that it increased the need for a means whereby Chinese private equity funds could exit their investments at an early opportunity and on their own market. The creation of the Second Board was therefore a belated response to this need.II. Rules and regulations governing the establishment of the Second BoardWe now take a closer look at some of the rules and regulations governing the establishment of the Second Board.First , the Interim Measures on the Administration of Initial Public Offerings andListings of Shares on the ChiNext, issued by the CSRC on 31 March 2009 with effect from 1 May 2009. The Interim Measures consist of six chapters and 58 articles, stipulating issue terms and procedures, disclosure requirements, regulatory procedures, and legal responsibilities.First, the General Provisions chapter. The first thing this says (Article 1) is: "These Measures are formulated for the purposes of promoting the development of innovative enterprises and other growing start-ups" This shows that one of the main listing criteria is a company's technological innovativeness and growth potential. The Chinese authorities have actually made it clear that, although the Second Board and the SME Board are both intended for SMEs of similar sizes, the Second Board is specifically intended for SMEs at the initial (rather than the growth or mature) stage of their development with a high degree of technological innovativeness and an innovative business model while the SME Board is specifically intended for companies with relatively stable earnings at the mature stage of their development. They have also made it clear that the Second Board is not simply a "small SME Board." This suggests to us that the authorities want to see technologically innovative companies listing on the Second Board and SMEs in traditional sectors listing on the SME Board.Next, Article 7 says: "A market access system that is commensurate with the risk tolerance of investors shall be established for investors on the ChiNext and investment risk shall be fully disclosed to investors." One noteworthy feature is the adoption of the concept of the "qualified investor" in an attempt to improve risk control.Furthermore, Article 8 says: "China Securities Regulatory Commission (hereinafter, CSRC) shall, in accordance with law, examine and approve the issuer’s IPO application and supervise the issuer’s IPO activities. The stock exchange shall formulate rules in accordance with law, provide an open, fair and equitable market environment and ensure the normal operation of the ChiNext." Until the Second Board was established, it was thought by some that the stock exchange had the right to approve new issues. Under the Interim Measures, however, it is the CSRC that examines and approves applications.First, offering conditions. Article 10 stipulates four numerical conditions for companies applying for IPOs.Second, offering procedures. The Interim Measures seek to make sponsoring securities companies more responsible by requiring them to conduct due diligence investigations and make prudential judgment on the issuer’s growth and render special opinions thereon.Third, information disclosure. Article 39 of the Interim Measures stipulates that the issuer shall make a statement in its prospectus pointing out the risks of investing in Second Board companies: namely, inconsistent performance, high operational risk, and the risk of delisting. Similarly,Fourth, supervision. Articles 51 and 52 stipulate that the stock exchange (namely, the Shenzhen Stock Exchange) shall establish systems for listing, trading and delisting Second Board stocks, urge sponsors to fulfill their ongoing supervisory obligations, and establish a market risk warning system and an investor education system.1. Amendments to the Interim Measures on Securities Issuance and Listing Sponsor System and the Provisional Measures of the Public Offering Review Committee of the China Securities Regulatory Commission2. Rules Governing the Listing of Shares on the ChiNext of Shenzhen Stock Exchange Next, the Shenzhen Stock Exchange published Rules Governing the Listing of Shares on the ChiNext of Shenzhen Stock Exchange on 6 June (with effect from 1 July).3. Checking investor eligibility As the companies listed on the Second Board are more risky than those listed on the Main Board and are subject to more rigorous delisting rules (see above), investor protection requires that checks be made on whether Second Board shares are suitable for all those wishing to invest in them.4. Rules governing (1) application documents for listings on the ChiNext and (2) prospectuses of ChiNext companies On 20 July the CSRC published rules governing Application Documents for Initial Public Offerings and Listings of Shares on the ChiNext and Prospectuses of ChiNext Companies, and announced that it would begin processing listing applications on 26 July.III. Future developmentsAs Its purpose is to "promote the development of innovative enterprises and other growing start-ups"，the Second Board enables such companies to raise capital by issuing shares. That is why its listing requirements are less demanding than those of the Main Board but also why it has various provisions to mitigate risk. For one thing, the Second Board has its own public offering review committee to check how technologically specialized applicant companies are, reflecting the importance attached to this. For another, issuers and their controlling shareholders, de facto controllers, and sponsoring securities companies are subject to more demanding accountability requirements. The key factor here is, not surprisingly, disclosure. Also, the qualified investor system is designed to mitigate the risks to retail investors.Once the rules and regulations governing the Second Board were published, the CSRC began to process listing applications from 26 July 2009. It has been reported that 108 companies initially applied. As of mid-October, 28 of these had been approved and on 30 October they were listed on the Second Board.As of 15 December, there are 46 companies whose listing application has been approved by CSRC (including the above-mentioned 28 companies). They come from a wide range of sectors, especially information technology, services, and biopharmacy. Thus far, few companies in which foreign private equity funds have a stake have applied. This is because these funds have tended to go for red-chip listings.Another point is movement between the various tiers of China's multi-tier capital market. As of early September, four companies that are traded on the new Third Board had successfully applied to list on the Second Board. As 22 new Third Board companies meet the listing requirements of the Second Board on the basis of their interim reports for the first half of fiscal 2009, a growing number of companies may transfer their listing from the new Third Board to the Second Board. We think this is likely to make the new Third Board a more attractive market for private equity investors.The applicants include companies that were in the process of applying for a listing on the SME Board. The CSRC has also made it clear that it does not see theSecond Board simply as a "small SME Board" and attaches great importance to the companies' innovativeness and growth potential. Ultimately, whether or not such risks can be mitigated will depend on whether the quality of the companies that list on the Second Board improves and disclosure requirements are strictly complied with. For example, according to the rules governing Prospectuses of ChiNext Companies, companies are required to disclose the above-mentioned supplementary agreements as a control right risk. The point is whether such requirements will be complied with.Since there is a potentially large number of high-tech companies in China in the long term, whether or not the Second Board becomes one of the world's few successful venture capital markets will depend on whether all these rules and regulations succeed in shaping its development and the way in which it is run.The authorities clearly want to avoid a situation where the Second Board attracts a large number of second-rate companies and becomes a vehicle for market abuse as it would then run the risk of becoming an illiquid market shunned by investors who have lost trust in it. Indeed, such has been the number of companies applying to list on the Second Board that some observers have expressed concern about their quality.There has also been some concern about investor protection. For example, supplementary agreements between private equity funds and issuers pose a risk to retail investors in that they may suddenly be faced with a change in the controlling shareholder. This is because such agreements can result in a transfer of shares from the founder or controlling shareholder to a private equity fund if the company fails to meet certain agreed targets or in a shareholding structure that is different from the apparent one, for example. The problem of low liquidity, which has long faced the new Third Board market, where small-cap high-tech stocks are also traded, also needs to be addressed.Meanwhile, the Second Board's Public Offering Review Committee was officially established on 14 August. It has 35 members. A breakdown reveals that the number of representatives of the CSRC and the Shenzhen Stock Exchange has been limited to three and two, respectively, to ensure that the committee has the necessary number of technology specialists. Of the remainder, 14 are accountants, six lawyers,three from the Ministry of Science and Technology, three from the China Academy of Sciences, two from investment trust companies, one from an asset evaluation agency, and one from the National Development and Reform Commission (NDRC). It has been reported that the members include specialists in the six industry fields the CSRC considers particularly important for Second Board companies (namely, new energy, new materials, biotechnology and pharmaceuticals, energy conservation and environmental protection, services and IT).Source: Takeshi Jingu.2009.“China's Second Board”. Nomura Journal of Capital Markets Winter 2009 V ol.1 No.4.pp.1-15.二、翻译文章译文：中国创业板市场一、建立创业板市场及其意义2009年3月31日中国证券监督管理委员会(以下简称“中国证监会”)发行《中国证监会管理暂行办法》，首次在创业板市场上[即,第二个板,也叫创业板市场](“暂行办法”) 公开募股，从 2009年的5月1日开始生效，这标志着深圳证券交易所市场这个人们期待已久的合资企业即将诞生。

毕业论文外文翻译范例

外文原文(一)Savigny and his Anglo-American Disciple s*M. H. HoeflichFriedrich Carl von Savigny, nobleman, law reformer, champion of the revived German professoriate, and founder of the Historical School of jurisprudence, not only helped to revolutionize the study of law and legal institutions in Germany and in other civil law countries, but also exercised a profound influence on many of the most creative jurists and legal scholars in England and the United States. Nevertheless, tracing the influence of an individual is always a difficult task. It is especially difficult as regards Savigny and the approach to law and legal sources propounded by the Historical School. This difficulty arises, in part, because Savigny was not alone in adopting this approach. Hugo, for instance, espoused quite similar ideas in Germany; George Long echoed many of these concepts in England during the 1850s, and, of course, Sir Henry Sumner Maine also espoused many of these same concepts central to historical jurisprudence in England in the 1860s and 1870s. Thus, when one looks at the doctrinal writings of British and American jurists and legal scholars in the period before 1875, it is often impossible to say with any certainty that a particular idea which sounds very much the sort of thing that might, indeed, have been derived from Savigny's works, was, in fact, so derived. It is possible, nevertheless, to trace much of the influence of Savigny and his legal writings in the United States and in Great Britain during this period with some certainty because so great was his fame and so great was the respect accorded to his published work that explicit references to him and to his work abound in the doctrinal writing of this period, as well as in actual law cases in the courts. Thus, Max Gutzwiller, in his classic study Der einfluss Savignys auf die Entwicklung des International privatrechts, was able to show how Savigny's ideas on conflict of laws influenced such English and American scholars as Story, Phillimore, Burge, and Dicey. Similarly, Andreas Schwarz, in his "Einflusse Deutscher Zivilistik im Auslande," briefly sketched Savigny's influence upon John Austin, Frederick Pollock, and James Bryce. In this article I wish to examine Savigny's influence over a broader spectrum and to draw a picture of his general fame and reputation both in Britain and in the United States as the leading Romanist, legal historian, and German legal academic of his day. The picture of this Anglo-American respect accorded to Savigny and the historical school of jurisprudence which emerges from these sources is fascinating. It sheds light not only upon Savigny’s trans-channel, trans-Atlantic fame, but also upon the extraordinarily*M.H.Hoeflich, Savigny and his Anglo-American Disciples, American Journal of Comparative Law, vol.37, No.1, 1989.cosmopolitan outlook of many of the leading American and English jurists of the time. Of course, when one sets out to trace the influence of a particular individual and his work, it is necessary to demonstrate, if possible, precisely how knowledge of the man and his work was transmitted. In the case of Savigny and his work on Roman law and ideas of historical jurisprudence, there were three principal modes of transmission. First, there was the direct influence he exercised through his contacts with American lawyers and scholars. Second, there was the influence he exercised through his books. Third, there was the influence he exerted indirectly through intermediate scholars and their works. Let us examine each mode separately.I.INFLUENCE OF THE TRANSLATED WORKSWhile American and British interest in German legal scholarship was high in the antebellum period, the number of American and English jurists who could read German fluently was relatively low. Even those who borrowed from the Germans, for instance, Joseph Story, most often had to depend upon translations. It is thus quite important that Savigny’s works were amongst the most frequently translated into English, both in the United States and in Great Britain. His most influential early work, the Vom Beruf unserer Zeitfur Rechtsgeschichte und Gestzgebung, was translated into English by Abraham Hayward and published in London in 1831. Two years earlier the first volume of his History of Roman Law in the Middle Ages was translated by Cathcart and published in Edinburgh. In 1830, as well, a French translation was published at Paris. Sir Erskine Perry's translation of Savigny's Treatise on Possession was published in London in 1848. This was followed by Archibald Brown's epitome of the treatise on possession in 1872 and Rattigan's translation of the second volume of the System as Jural Relations or the Law of Persons in 1884. Guthrie published a translation of the seventh volume of the System as Private International Law at Edinburgh in 1869. Indeed, two English translations were even published in the far flung corners of the British Raj. A translation of the first volume of the System was published by William Holloway at Madras in 1867 and the volume on possession was translated by Kelleher and published at Calcutta in 1888. Thus, the determined English-speaking scholar had ample access to Savigny's works throughout the nineteenth century.Equally important for the dissemination of Savigny's ideas were those books and articles published in English that explained and analyzed his works. A number of these must have played an important role in this process. One of the earliest of these is John Reddie's Historical Notices of the Roman law and of the Progress of its Study in Germany, published at Edinburgh in 1826. Reddie was a noted Scots jurist and held the Gottingen J.U.D. The book, significantly, is dedicated to Gustav Hugo. It is of that genre known as an external history of Roman law-not so much a history of substantive Roman legal doctrine but rather a historyof Roman legal institutions and of the study of Roman law from antiquity through the nineteenth century. It is very much a polemic for the study of Roman law and for the Historical School. It imparts to the reader the excitement of Savigny and his followers about the study of law historically and it is clear that no reader of the work could possibly be left unmoved. It is, in short, the first work of public relations in English on behalf of Savigny and his ideas.Having mentioned Reddie's promotion of Savigny and the Historical School, it is important to understand the level of excitement with which things Roman and especially Roman law were greeted during this period. Many of the finest American jurists were attracted-to use Peter Stein's term-to Roman and Civil law, but attracted in a way that, at times, seems to have been more enthusiastic than intellectual. Similarly, Roman and Civil law excited much interest in Great Britain, as illustrated by the distinctly Roman influence to be found in the work of John Austin. The attraction of Roman and Civil law can be illustrated and best understood, perhaps, in the context of the publicity and excitement in the English-speaking world surrounding the discovery of the only complete manuscript of the classical Roman jurist Gaius' Institutes in Italy in 1816 by the ancient historian and German consul at Rome, B.G. Niebuhr. Niebuhr, the greatest ancient historian of his time, turned to Savigny for help with the Gaius manuscript (indeed, it was Savigny who recognized the manuscript for what it was) and, almost immediately, the books and journals-not just law journals by any means-were filled with accounts of the discovery, its importance to legal historical studies, and, of course, what it said. For instance, the second volume of the American Jurist contains a long article on the civil law by the scholarly Boston lawyer and classicist, John Pickering. The first quarter of the article is a gushing account of the discovery and first publication of the Gaius manuscript and a paean to Niebuhr and Savigny for their role in this. Similarly, in an article published in the London Law Magazine in 1829 on the civil law, the author contemptuously refers to a certain professor who continued to tell his students that the text of Gaius' Institutes was lost for all time. What could better show his ignorance of all things legal and literary than to be unaware of Niebuhr's great discovery?Another example of this reaction to the discovery of the Gaius palimpsest is to be found in David Irving's Introduction to the Study of the Civil Law. This volume is also more a history of Roman legal scholarship and sources than a study of substantive Roman law. Its pages are filled with references to Savigny's Geschichte and its approach clearly reflects the influence of the Historical School. Indeed, Irving speaks of Savigny's work as "one of the most remarkable productions of the age." He must have been truly impressed with German scholarship and must also have been able to convince the Faculty of Advocates, forwhom he was librarian, of the worth of German scholarship, for in 1820 the Faculty sent him to Gottingen so that he might study their law libraries. Irving devotes several pages of his elementary textbook on Roman law to the praise of the "remarkable" discovery of the Gaius palimpsest. He traces the discovery of the text by Niebuhr and Savigny in language that would have befitted an adventure tale. He elaborates on the various labors required to produce a new edition of the text and was particularly impressed by the use of a then new chemical process to make the under text of the palimpsest visible. He speaks of the reception of the new text as being greeted with "ardor and exultation" strong words for those who spend their lives amidst the "musty tomes" of the Roman law.This excitement over the Verona Gaius is really rather strange. Much of the substance of the Gaius text was already known to legal historians and civil lawyers from its incorporation into Justinian's Institutes and so, from a substantive legal perspective, the find was not crucial. The Gaius did provide new information on Roman procedural rules and it did also provide additional information for those scholars attempting to reconstruct pre-Justinianic Roman law. Nevertheless, these contributions alone seem hardly able to justify the excitement the discovery caused. Instead, I think that the Verona Gaius discovery simply hit a chord in the literary and legal community much the same as did the discovery of the Rosetta Stone or of Schliemann’s Troy. Here was a monument of a great civilization brought newly to light and able to be read for the first time in millenia. And just as the Rosetta Stone helped to establish the modern discipline of Egyptology and Schliemann's discoveries assured the development of classical archaeology as a modern academic discipline, the discovery of the Verona Gaius added to the attraction Roman law held for scholars and for lawyers, even amongst those who were not Romanists by profession. Ancillary to this, the discovery and publication of the Gaius manuscript also added to the fame of the two principals involved in the discovery, Niebuhr and Savigny. What this meant in the English-speaking world is that even those who could not or did not wish to read Savigny's technical works knew of him as one of the discoverers of the Gaius text. This fame itself may well have helped in spreading Savigny's legal and philosophical ideas, for, I would suggest, the Gaius "connection" may well have disposed people to read other of Savigny's writings, unconnected to the Gaius, because they were already familiar with his name.Another example of an English-speaking promoter of Savigny is Luther Stearns Cushing, a noted Boston lawyer who lectured on Roman law at the Harvard Law School in 1848-49 and again in 1851- 1852.Cushing published his lectures at Boston in 1854 under the title An Introduction to the Study of Roman Law. He devoted a full chapter to a description of the historical school and to the controversy betweenSavigny and Thibaut over codification. While Cushing attempted to portray fairly the arguments of both sides, he left no doubt as to his preference for Savigny's approach:The labors of the historical school have established an entirely new and distinct era in the study of the Roman jurisprudence; and though these writers cannot be said to have thrown their predecessors into the shade, it seems to be generally admitted, that almost every branch of the Roman law has received some important modification at their hands, and that a knowledge of their writings, to some extent, at least, is essentially necessary to its acquisition.译文(一)萨维尼和他的英美信徒们*M·H·豪弗里奇弗雷德里奇·卡尔·冯·萨维尼出身贵族，是一位出色的法律改革家，也是一位倡导重建德国教授协会的拥护者，还是历史法学派的创建人之一。

毕业论文文献外文翻译----危机管理：预防,诊断和干预文献翻译-中英文文献对照翻译

第1页共19页中文3572字毕业论文（设计）外文翻译标题：危机管理-预防，诊断和干预一、外文原文标题：标题：Crisis management: prevention, diagnosis and Crisis management: prevention, diagnosis andintervention 原文：原文：The Thepremise of this paper is that crises can be managed much more effectively if the company prepares for them. Therefore, the paper shall review some recent crises, theway they were dealt with, and what can be learned from them. Later, we shall deal with the anatomy of a crisis by looking at some symptoms, and lastly discuss the stages of a crisis andrecommend methods for prevention and intervention. Crisis acknowledgmentAlthough many business leaders will acknowledge thatcrises are a given for virtually every business firm, many of these firms do not take productive steps to address crisis situations. As one survey of Chief Executive officers of Fortune 500 companies discovered, 85 percent said that a crisisin business is inevitable, but only 50 percent of these had taken any productive action in preparing a crisis plan(Augustine, 1995). Companies generally go to great lengths to plan their financial growth and success. But when it comes to crisis management, they often fail to think and prepare for those eventualities that may lead to a company’s total failure.Safety violations, plants in need of repairs, union contracts, management succession, and choosing a brand name, etc. can become crises for which many companies fail to be prepared untilit is too late.The tendency, in general, is to look at the company as a perpetual entity that requires plans for growth. Ignoring the probabilities of disaster is not going to eliminate or delay their occurrences. Strategic planning without inclusion ofcrisis management is like sustaining life without guaranteeinglife. One reason so many companies fail to take steps to proactively plan for crisis events, is that they fail to acknowledge the possibility of a disaster occurring. Like an ostrich with its head in the sand, they simply choose to ignorethe situation, with the hope that by not talking about it, it will not come to pass. Hal Walker, a management consultant, points out “that decisions will be more rational and better received, and the crisis will be of shorter duration, forcompanies who prepare a proactive crisis plan” (Maynard, 1993) .It is said that “there are two kinds of crises: those that thatyou manage, and those that manage you” (Augustine, 1995). Proactive planning helps managers to control and resolve a crisis. Ignoring the possibility of a crisis, on the other hand,could lead to the crisis taking a life of its own. In 1979, theThree-Mile Island nuclear power plant experienced a crisis whenwarning signals indicated nuclear reactors were at risk of a meltdown. The system was equipped with a hundred or more different alarms and they all went off. But for those who shouldhave taken the necessary steps to resolve the situation, therewere no planned instructions as to what should be done first. Hence, the crisis was not acknowledged in the beginning and itbecame a chronic event.In June 1997, Nike faced a crisis for which they had no existi existing frame of reference. A new design on the company’s ng frame of reference. A new design on the company’s Summer Hoop line of basketball shoes - with the word air writtenin flaming letters - had sparked a protest by Muslims, who complained the logo resembled the Arabic word for Allah, or God.The council of American-Islamic Relations threatened aa globalNike boycott. Nike apologized, recalled 38,000 pairs of shoes,and discontinued the line (Brindley, 1997). To create the brand,Nike had spent a considerable amount of time and money, but hadnever put together a general framework or policy to deal with such controversies. To their dismay, and financial loss, Nike officials had no choice but to react to the crisis. This incident has definitely signaled to the company that spending a little more time would have prevented the crisis. Nonetheless,it has taught the company a lesson in strategic crisis management planning.In a business organization, symptoms or signals can alert the strategic planners or executives of an eminent crisis. Slipping market share, losing strategic synergy anddiminishing productivity per man hour, as well as trends, issues and developments in the socio-economic, political and competitive environments, can signal crises, the effects of which can be very detrimental. After all, business failures and bankruptcies are not intended. They do not usually happen overnight. They occur more because of the lack of attention to symptoms than any other factor.Stages of a crisisMost crises do not occur suddenly. The signals can usuallybe picked up and the symptoms checked as they emerge. A company determined to address these issues realizes that the real challenge is not just to recognize crises, but to recognize themin a timely fashion (Darling et al., 1996). A crisis can consistof four different and distinct stages (Fink, 1986). The phasesare: prodromal crisis stage, acute crisis stage, chronic crisisstage and crisis resolution stage.Modern organizations are often called “organic” due tothe fact that they are not immune from the elements of their surrounding environments. Very much like a living organism, organizations can be affected by environmental factors both positively and negatively. But today’s successfulorganizations are characterized by the ability to adapt by recognizing important environmental factors, analyzing them, evaluating the impacts and reacting to them. The art of strategic planning (as it relates to crisis management)involves all of the above activities. The right strategy, in general, provides for preventive measures, and treatment or resolution efforts both proactively and reactively. It wouldbe quite appropriate to examine the first three stages of acrisis before taking up the treatment, resolution or intervention stage.Prodromal crisis stageIn the field of medicine, a prodrome is a symptom of the onset of a disease. It gives a warning signal. In business organizations, the warning lights are always blinking. No matter how successful the organization, a number of issues andtrends may concern the business if proper and timely attentionis paid to them. For example, in 1995, Baring Bank, a UK financial institution which had been in existence since 1763,ample opportunitysuddenly and unexpectedly failed. There wasfor the bank to catch the signals that something bad was on thehorizon, but the company’s efforts to detect that were thwarted by an internal structure that allowed a single employee both to conduct and to oversee his own investment trades, and the breakdown of management oversight and internalcontrol systems (Mitroff et al., 1996). Likewise, looking in retrospect, McDonald’s fast food chain was given the prodromalsymptoms before the elderly lady sued them for the spilling ofa very hot cup of coffee on her lap - an event that resulted in a substantial financial loss and tarnished image of thecompany. Numerous consumers had complained about thetemperature of the coffee. The warning light was on, but the company did not pay attention. It would have been much simplerto pick up the signal, or to check the symptom, than facing the consequences.In another case, Jack in the Box, a fast food chain, had several customers suffer intestinal distress after eating at their restaurants. The prodromal symptom was there, but the company took evasive action. Their initial approach was to lookaround for someone to blame. The lack of attention, the evasiveness and the carelessness angered all the constituent groups, including their customers. The unfortunate deaths thatptoms,occurred as a result of the company’s ignoring thesymand the financial losses that followed, caused the company to realize that it would have been easier to manage the crisis directly in the prodromal stage rather than trying to shift theblame.Acute crisis stageA prodromal stage may be oblique and hard to detect. The examples given above, are obvious prodromal, but no action wasWebster’s New Collegiate Dictionary, an acute stage occursacutewhen a symptom “demands urgent attention.” Whether the acutesymptom emerges suddenly or is a transformation of a prodromalstage, an immediate action is required. Diverting funds and other resources to this emerging situation may cause disequilibrium and disturbance in the whole system. It is onlythose organizations that have already prepared a framework forthese crises that can sustain their normal operations. For example, the US public roads and bridges have for a long time reflected a prodromal stage of crisis awareness by showing cracks and occasionally a collapse. It is perhaps in light of the obsessive decision to balance the Federal budget that reacting to the problem has been delayed and ignored. This situation has entered an acute stage and at the time of this writing, it was reported that a bridge in Maryland had just collapsed.The reason why prodromes are so important to catch is thatit is much easier to manage a crisis in this stage. In the caseof most crises, it is much easier and more reliable to take careof the problem before it becomes acute, before it erupts and causes possible complications (Darling et al., 1996). In andamage. However, the losses are incurred. Intel, the largest producer of computer chips in the USA, had to pay an expensiveprice for initially refusing to recall computer chips that proved unreliable o n on certain calculations. The f irmfirm attempted to play the issue down and later learned its lesson. At an acutestage, when accusations were made that the Pentium Chips were not as fast as they claimed, Intel quickly admitted the problem,apologized for it, and set about fixing it (Mitroff et al., 1996). Chronic crisis stageDuring this stage, the symptoms are quite evident and always present. I t isIt is a period of “make or break.” Being the third stage, chronic problems may prompt the company’s management to once and for all do something about the situation. It may be the beginning of recovery for some firms, and a deathknell for others. For example, the Chrysler Corporation was only marginallysuccessful throughout the 1970s. It was not, however, until the company was nearly bankrupt that amanagement shake-out occurred. The drawback at the chronic stage is that, like in a human patient, the company may get used to “quick fixes” and “band “band--aid”approaches. After all, the ailment, the problem and the crisis have become an integral partoverwhelmed by prodromal and acute problems that no time or attention is paid to the chronic problems, or the managers perceive the situation to be tolerable, thus putting the crisison a back burner.Crisis resolutionCrises could be detected at various stages of their development. Since the existing symptoms may be related todifferent problems or crises, there is a great possibility thatthey may be misinterpreted. Therefore, the people in charge maybelieve they have resolved the problem. However, in practicethe symptom is often neglected. In such situations, the symptomwill offer another chance for resolution when it becomes acute,thereby demanding urgent care. Studies indicate that today anincreasing number of companies are issue-oriented and searchfor symptoms. Nevertheless, the lack of experience in resolvinga situation and/or inappropriate handling of a crisis can leadto a chronic stage. Of course, there is this last opportunityto resolve the crisis at the chronic stage. No attempt to resolve the crisis, or improper resolution, can lead to grim consequences that will ultimately plague the organization or even destroy it.It must be noted that an unsolved crisis may not destroy the company. But, its weakening effects can ripple through the organization and create a host of other complications.Preventive effortsThe heart of the resolution of a crisis is in the preventiveefforts the company has initiated. This step, similar to a humanbody, is actually the least expensive, but quite often the mostoverlooked. Preventive measures deal with sensing potential problems (Gonzales-Herrero and Pratt, 1995). Major internalfunctions of a company such as finance, production, procurement, operations, marketing and human resources are sensitive to thesocio-economic, political-legal, competitive, technological, demographic, global and ethical factors of the external environment. What is imminently more sensible and much more manageable, is to identify the processes necessary forassessing and dealing with future crises as they arise (Jacksonand Schantz, 1993). At the core of this process are appropriate information systems, planning procedures, anddecision-making techniques. A soundly-based information system will scan the environment, gather appropriate data, interpret this data into opportunities and challenges, and provide a concretefoundation for strategies that could function as much to avoid crises as to intervene and resolve them.Preventive efforts, as stated before, require preparations before any crisis symptoms set in. Generally strategic forecasting, contingency planning, issues analysis, and scenario analysis help to provide a framework that could be used in avoiding and encountering crises.出处：出处：Toby TobyJ. Kash and John R. Darling . Crisis management: prevention, diagnosis 179-186二、翻译文章标题：危机管理：预防，诊断和干预译文：本文的前提是，如果该公司做好准备得话，危机可以更有效地进行管理。

英文翻译附原文

本科毕业设计(论文) 外文翻译（附外文原文）系 ( 院 )：资源与环境工程系课题名称：英文翻译专业(方向)：环境工程班级：2004-1班学生：3040106119指导教师：刘辉利副教授日期：2008年4月20使用褐煤（一种低成本吸附剂）从酸性矿物废水中去除和回收金属离子a. 美国, 大学公园, PA 16802, 宾夕法尼亚州立大学, 能源部和Geo 环境工程学.b. 印度第80号邮箱, Mahatma Gandhi ・Marg, Lucknow 226001, 工业毒素学研究中心, 环境化学分部,于2006 年5月6 日网上获得，2006 年4月24 日接受，2006 年3月19 日;校正，2006 年2月15 日接收。

摘要酸性矿物废水(AMD), 是一个长期的重大环境问题，起因于钢硫铁矿的微生物在水和空气氧化作用, 买得起包含毒性金属离子的一种酸性解答。

这项研究的主要宗旨是通过使用褐煤（一种低成本吸附剂）从酸性矿水(AMD)中去除和回收金属离子。

褐煤已被用于酸性矿水排水AMD 的处理。

经研究其能吸附亚铁, 铁, 锰、锌和钙在multi-component 含水系统中。

研究通过在不同的酸碱度里进行以找出最适宜的酸碱度。

模拟工业条件进行酸性矿物废水处理, 所有研究被进行通过单一的并且设定多专栏流动模式。

空的床接触时间(EBCT) 模型被使用为了使吸附剂用量减到最小。

金属离子的回收并且吸附剂的再生成功地达到了使用0.1 M 硝酸不用分解塔器。

关键词:吸附; 重金属; 吸附; 褐煤; 酸性矿物废水处理; 固体废料再利用; 亚铁; 铁; 锰。

文章概述1. 介绍2. 材料和方法2.1. 化学制品、材料和设备3. 吸附步骤3.1. 酸碱度最佳化3.2. 固定床研究3.2.1 单一栏3.2.2 多栏4. 结果和讨论4.1. ZPC 和渗析特征4.2 酸碱度的影响4.3. Multi-component 固定吸附床4.3.1 褐煤使用率4.4. 吸附机制4.5. 解吸附作用研究5. 结论1. 介绍酸性矿物废水(AMD) 是一个严重的环境问题起因于硫化物矿物风化, 譬如硫铁矿(FeS2) 和它的同素异形体矿物(α-FeS) 。

5、外文文献翻译(附原文)产业集群,区域品牌,Industrial cluster ,Regional brand

外文文献翻译（附原文）外文译文一：产业集群的竞争优势——以中国大连软件工业园为例Weilin Zhao,Chihiro Watanabe，Charla-Griffy-Brown[J]. Marketing Science,2009(2):123-125.摘要：本文本着为促进工业的发展的初衷探讨了中国软件公园的竞争优势。

产业集群深植于当地的制度系统，因此拥有特殊的竞争优势。

根据波特的“钻石”模型、SWOT模型的测试结果对中国大连软件园的案例进行了定性的分析。

产业集群是包括一系列在指定地理上集聚的公司，它扎根于当地政府、行业和学术的当地制度系统，以此获得大量的资源，从而获得产业经济发展的竞争优势。

为了成功驾驭中国经济范式从批量生产到开发新产品的转换，持续加强产业集群的竞争优势,促进工业和区域的经济发展是非常有必要的。

关键词：竞争优势；产业集群；当地制度系统；大连软件工业园；中国；科技园区；创新；区域发展产业集群产业集群是波特[1]也推而广之的一个经济发展的前沿概念。

作为一个在全球经济战略公认的专家,他指出了产业集群在促进区域经济发展中的作用。

他写道：集群的概念,“或出现在特定的地理位置与产业相关联的公司、供应商和机构，已成为了公司和政府思考和评估当地竞争优势和制定公共决策的一种新的要素。

但是，他至今也没有对产业集群做出准确的定义。

最近根据德瑞克、泰克拉[2]和李维[3]检查的关于产业集群和识别为“地理浓度的行业优势的文献取得了进展”。

“地理集中”定义了产业集群的一个关键而鲜明的基本性质。

产业由地区上特定的众多公司集聚而成,他们通常有共同市场、,有着共同的供应商,交易对象,教育机构和其它像知识及信息一样无形的东西，同样地,他们也面临相似的机会和威胁。

在全球产业集群有许多种发展模式。

比如美国加州的硅谷和马萨诸塞州的128鲁特都是知名的产业集群。

前者以微电子、生物技术、和风险资本市场而闻名,而后者则是以软件、计算机和通讯硬件享誉天下[4]。

外文翻译原文.

e c o l o g i c a l e n g i n e e r i n g 28(2006124–130a v a i l ab l e a t w w w.sc i e n c ed i re c t.c omj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /e c o l e n gPlant-bioﬁlm oxidation ditch for in situ treatm ent of polluted watersQi-Tang Wu a ,∗,Ting Gao a ,Shucai Zeng a ,Hong Chua ba College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,ChinabDepartment of Civil and Structural Engineering,Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong SAR,Chinaa r t i c l ei n f o Article history:Received 17December 2005Received in revised form 16May 2006Accepted 18May 2006Keywords:Plant-bioﬁlm oxidation ditch (PBFODIn situWastewater treatmenta b s t r a c tEutrophication of surface water bodies is a problem of increasing environmental and ecolog-ical concern worldwide and is particularly serious in China.In the present study,oxidation ditches were connected to a lake receiving municipal sewage sludges.T wo 24m 2(width 2m,length 12mparallel plastic oxidation ditches material were installed on a lake near the inlet of the municipal sewage.Zizania caduciﬂora and Canna generalis were grown in the ditches with plastic ﬂoating supporters for the removal of N and P from the sewage.The experiment was conducted ﬁrstly with municipal sewage in autumn–winter seasons for about 150daysunder the following conditions:2m 3/h inﬂuent ﬂow,0.75kW jet-ﬂow aerator(air/water of 5,18h HRT (hydrological retention timeand a return ratio of 10.Then it was run with the polluted lake water in summer–autumn for about 160days with an aerator of 1.25kW and an inﬂuent of 6m 3/h (air/water 3.3,HRT 6h.The performance was quite stable during the experimental period for the municipal sewage treatment.The average removal rates of COD (chemical oxygen demand,SS (suspended solids,TP (total phosphorus,NH 4+-N and inorganic-N were 70.6,75.8,72.6,52.1and50.3%,respectively.For the polluted lake water treatment,the average concentrations of COD,NH 4+-N and TP were 42.7,13.1and 1.09mg/L,respectively,in the inﬂuent and were 25.1,6.4and 0.38mg/L,respectively,in the efﬂuent.The capacity of the plants to remove N and P by direct uptake was limited,but the indi-rect mechanisms also occurred.The proposed process,transforming the natural lake into a wastewater treatment plant,could evidently reduce the costs of the sewage collection,the land space requirement and the construction compared with conventional sewage treat-ment plants,and is especially suited to conditions in south China and south-east Asia.©2006Elsevier B.V .All rights reserved.1.IntroductionMany water bodies are subject to eutrophication due to eco-nomic constraints in reducing point sources of nutrients and/or to a high proportion of diffuse sources,and the prob-lem is particularly common in China because the proportion of treated municipal sewage is still low due to the relatively high capital investmentrequired.Accordingly,43.5%of 130investi-gated major lakes in China were found to be highly eutrophied∗Corresponding author .Tel.:+862085280296;fax:+862085288326.E-mail address:qitangwu@ (Q.-T.Wu.and 45%were of intermediate status (Li et al.,2000.These pol-luted lakes were mainly located in economically developed regions and especially around cities where large amounts of municipal sewage are discharged without appropriate treat-ment.Increasingly,natural or constructed wetlands,including buffer zones(Correll,2005,are being used for removal of pol-lutants from wastewater or for treatment of stormwater runoff from agricultural land and other non-point sources (Mitsch ete c o l o g i c a l e n g i n e e r i n g28(2006124–130125Table1–COD and BOD5of the study lake sampled at three points for5days inMay2003COD(mg/LBOD5(mg/LBOD5/COD13May89.5135.700.4083.3334.500.4189.5136.600.4114May55.5624.800.4589.5135.200.3949.3820.900.4227May105.1141.300.3981.0832.300.40111.1141.000.3728May60.0026.830.4563.3327.700.4463.3327.000.4329May90.0035.700.4093.3337.000.40117.9949.400.42al.,2000;Coveney et al.,2002;Belmont et al.,2004.However, this method requires a large land area in addition to the lake in question.For in situ treatment of hypereutrophic water bodies where the transparency of the water does not allow regrowth of submerged macrophytes,phosphorus precipitation in eutrophic lakes by iron application(Deppe and Benndorf, 2002or by additions of lime(Walpersdorf et al.,2004has been reported.Aeration of river water has been employed to remediate polluted rivers since the1970s(Wang et al.,1999. Increasing oxygen transfer inﬂow by stones placed in rivers was studied by Cokgor and Kucukali(2004.Growingﬂoating aquatic macrophytes(Sooknah and Wilkie,2004or terrestrial green plants usingﬂoating supports(Li and Wu,1997,physical ecological engineering(PEEN(Pu et al.,1998,and biotic addi-tives have also been applied(Chen,2003.However,these sim-ple designs do not constitute a real water treatment system and the efﬁciencies of these treatments are unsatisfactory.Activated sludge systems have been proved efﬁcient treat-ing municipal sewage since the1960s(Ray,1995.However, this type of system has not been used for in situ remediation of polluted lakes or rivers.In the present study,the oxidation ditch technique was adopted on a lake receiving municipal sewage sludge.Floating green plants and the bioﬁlms com-prisingﬂoating materials and plant roots were also added to enhance N and P removal.A pilot scale experiment was set up to test the feasibility and performance of the plant-enhanced oxidation ditch for in situ treatment ofboth the municipal sewage and the polluted lake water.2.Experimental2.1.Site descriptionThe study lake was situated at South China Agricultural Uni-versity,Guangzhou,China.The area of the lake was about 10000m2and the depth0.5–3m.This lake received the munic-ipal sewage from the residential area around the university.Fig.1–Surface arrangement of the plant-bioﬁlm oxidation ditch and the waterﬂows.(1Wall of nylon tissue;(2nets of5mm;(3nets of0.25mm;(4oxidation ditch;(5jet-ﬂow aerator;(6water pump;(7ﬂoating green plants;(8sewage entry.2.2.Establishment of the plant-bioﬁlm oxidationditchesT wo24m2(width2m,length12mparallel oxidation ditches made of plastic materials were installed along the lake bank near the sewage inlet.The inner ditch was made of cement and the outer ditch was isolated with nylon tissues andﬁx-ing PVC(polyvinyl chloridetubes.Fig.1showsthe surface arrangement and the waterﬂow path.The coarse suspended solids in the inﬂuent wereﬁltered by two pl astic nets,one with a pore size of5mm and the other with a pore size of0.25mm,whereas the suspended solids in the efﬂuent wereﬁltered by a plastic net with a pore size of 0.25mm.Zizania caduciﬂora and Canna generalis were grown in the ditch with theplast icﬂoating supporters which held the plants in position.Theﬂoating supporters were made of closed126e c o l o g i c a l e n g i n e e r i n g28(2006124–130PVC tubes and nylon nets and each was3.6m2.Zizania caduci-ﬂora was grown on twoﬂoating supporters an d Canna gener-alis on another two supporters.The plants were planted in four columns andﬁve lines.The twoﬂoating supporters with Canna generalis were near the inﬂuent and the two with Zizania caduciﬂora were near the efﬂuent.The entire disposal system is shown in Photo1.2.3.Conduct of the experimentsAn experiment was conductedﬁrstly on municipal sewage in autumn–winter seasons of2003–2004for about150days. The aeration of the oxidation ditch was achieved using a jet-ﬂow aerator of0.75kW(Aqua Co.,Italy;air generation10m3/h, water jet rate22–28m3/h.The water sampling started on18 September2003and endedon12February2004.The inﬂuent was2m3/h created by a water pump of0.37kW.With the jet-ﬂow aerator of0.75kW the theoretical air/water ratio was5, HRT was18h and the return ratio was10–13.The system was then run with the polluted lake water in summer and autumn2004for about160days with an aerator of1.25kW and with an inﬂuent of6m3/h(air/water3.3,HRT 6h.The inﬂuent was not created by water pump but by the driving fo rce of the jet-ﬂow aerator.The water sampling for the second run started on15May2004and endedon15October 2004.2.4.Sampling and analysisThe inﬂuent and efﬂuent were sampled every3–5days at 08:00–09:00a.m.andat17:00–18:00p.m.,each with three sam-pling re plicates for theﬁrst run.For the second run,the inﬂu-ent and efﬂuent were sampled1day a week.The water sam-pler took0–30cm surface water.The samples were analyzed for COD Cr,BOD5,SS,TP,NO3−-N,NH4+-N and pH according to standard methods(APHA,1995.The plant s were transplanted ontoﬂoating supporters two weeks before water sampling and theﬁrst harvest was carried out60days later and at the termination of theﬁrst run for the municipal sewage.The plant biomass and N and P con-tents were measured according to the methods proposed by the Soil and Agro-Chemical Analysis Committee of China(Lu, 2000.The total uptakes of N and P were calculated and com-pared with the total removal of these elements calculated by the cumulative removal each day following measurement of a water sample.Total N removal=(average N in inﬂuent−average N in efﬂuent×48×D iwhere48was the treated water volume per day in m3/day;D i was the number of days following the water sampling and before the next sampling.3.Results and discussionTable2shows the removal of COD Cr and SS by plant-bioﬁlm oxidation ditch for the treatment of the municipal sewage in autumn–winter seasons of2003–2004.The removal of COD Cr varied from60to79%with an average of70%for the inﬂuent COD Cr ranging from100to200mg/L,a nd resulted in efﬂuent COD Cr valuesfrom30to55mg/L(Table2,Fig.2.The average removal percentage was about75%for SS and variedfrom68to82%(Table2.The efﬂuent SS was about 30mg/L which is the efﬂuent limit value of the second grade for the sewage treatment plants in China(GB18918,2002 (Fig.3,for the inﬂuents varying from60to240mg/L.The average NH4+-N removal from inﬂuent was52%,which was lower in winter than in autumn(Table3.This may be due to lower bacterial activity in winter,but theinﬂuent NH4+-NTable2–Removal of COD and SS by the plant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage each month in autumn–winter seasons of2003–2004Period Sampled days Water temperature(◦CInﬂuent(mg/LEfﬂuent(mg/LRemoval(%COD Cr18–30September528.0118.54(3.01a34.34(7.8367.74 3–28October826.1123.91(4.0333.51(4.2672.661–7November326.0153.94(2.7337.60(3.8175.4918–28November423.1170.22(4.2835.45(5.3778.711–15December419.3180.36(8.2039.24(7.0677.6511–31January314.5128.46(3.6652.04(5.2359.504–12February216.8178.35(4.1662.86(5.8362.47Average150.54(4.3042.15(5.6370.60SS18–30September528.0160.4041.6074.18 3–28October826.1144.3826.2581.171–7November326.0116.0033.3370.7918–28November423.1111.7521.5080.981–15December419.390.5028.5068.4211–31January314.5104.0017.3382.384–12February216.8120.5033.0072.57Average121.0828.7975.78e c o l o g i c a l e n g i n e e r i n g28(2006124–130127Fig.2–COD in the inﬂuent and efﬂuent of the plant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage in autumn–winter seasons of2003–2004.was also higher in winter(Fig.4probably because of lower water consumption in the cold season.The total inorganic-N removal was similar to that for NH4+-N(Table3.NO3−-N concentrations were rather similar in the inﬂuent and the efﬂuent.The total P removal varied from63to78%and was higher and more regular than N removal(Table3.The P concentra-tion in treated efﬂuent was about1mg/L(Fig.5and conformed to the Chinese municipal sewage treatment standard which is set to3mg/L for second grade regions and1.5forﬁrst grade regions(GB18918,2002.Fig.6shows typical changes in the water quality param-eters for the sampling points from inlet to outlet.Thisindi-Fig.3–Suspended solids concentration in the inﬂuent and efﬂuent of the p lant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage in autumn–winter seasons of2003–2004.cates that COD and SS decreased gradually,but NH4+-N and TP dropped substantially following the mixing with the return water by the aerator and then decreased slowly,while NO3−-N and pH of the water remained virtually unchanged.The water DO increased dramatically following the aeration,decreased slowly thereafter and remained rather high even in the efﬂu-ent(about5.5mg/L.For the second run treating the polluted lake water on-site,the average inﬂuent COD Cr was42.7mg/L and the efﬂuent 25.1mg/L for about160days during summer–autumn seasons (Fig.7.The removal of NH4+-N was about50%from about13.1 to6.4mg/L.Total-P in the efﬂuents was rather stable,bei ngTable3–The removal of N and P by the plant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage for each month in autumn–winter seasons of2003–2004Period Sampled days Water temperature(◦CInﬂuent(mg/LEfﬂuent(mg/LRemoval(%NH4+-N18–30September528.020.60(0.30a7.16(0.2264.72 3–28October826.126.55(0.2310.15(0.2061.671–7November326.030.00(0.4113.67(0.2254.5118–28November423.135.15(0.7915.95(0.2653.991–15December419.335.89(0.3515.93(0.2755.1511–31January314.530.57(0.6918.59(0.2236.634–12February216.835.23(0.0521.61(0.0637.72Average30.57(0.4014.72(0.2152.06NH4+-N+NO3−-N18–30September528.023.06(0.159.24(0.1159.94 3–28October826.128.31(0.1212.01(0.1457.571–7November326.031.42(0.2114.58(0.1153.5918–28November423.136.32(0.4016.81(0.1353.721–15December419.337.41(0.1917.54(0.1453.1111–31January314.531.96(0.3720.07(0.1337.204–12February216.837.11(0.0323.35(0.0337.08Average32.23(0.2116.23(0.1150.32TP18–30September528.0 3.56(0.070.81(0.0475.56 3–28October826.1 4.01(0.140.87(0.0478.241–7November326.0 4.37(0.13 1.20(0.0472.5618–28November423.1 4.89(0.16 1.13(0.0776.661–15December319.5 4.86(0.80 1.38(0.2371.07 11–31January314.5 3.75(0.45 1.35(0.0363.32 4–12February216.8 4.75(0.10 1.51(0.0566.20 Average 4.31(0.16 1.16(0.0471.89128e c o l o g i c a l e n g i n e e r i n g 28(2006 124–130Fig.4–NH 4+-N concentration in the inﬂuent and efﬂuent of the plant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage in autumn–winter seasons of2003–2004.Fig.5–Total-P concentration in the inﬂuent and efﬂuent of the plant-bioﬁlm oxidation ditch for the in situ treatment of municipal sewage in autumn–winter seasons of2003–2004.Fig.6–T ypical changes in the pollutants in theplant-bioﬁlm oxidation ditch during the in situ treatment ofFig.7–The inﬂuent and efﬂuent concentrations of COD (up,NH 4+-N (medianand total-P (bottomin theplant-bioﬁlm oxidation ditch treating polluted lake water.about 0.38mg/L from an average of 1.09mg/L in the inﬂuents.The removal of COD Cr ,NH 4+-N and Total-P was then quite sat-isfactory both for the municipal sewage and the polluted lake water.The removal of N and P was somewhat higher than con-ventional oxidation ditches,perhaps due to the existence of the plant-bioﬁlm in the studiedsystem.However,the direct uptake rates of N and P by green plants were almost negligi-ble compared to the total removal of these elements by the whole system (Table4.However,the plants may have cre-ated localized anaerobic conditions by their root exudates and dead biomass and enhance the denitriﬁcation of N by micro-organisms as occurs in constructed wetlands (Hone,2000.Besides the green plants,the proposed system also con-tains bioﬁlm coated to the plastic materials.The high velocity of return-ﬂuent was different to the conventional oxidation ditch.Kugaprasatham et al.(1982showed that the increase of the ﬂuent velocity could increase the density of the bioﬁlm if the nutrient conditions were suitable for bacteria growth.Simultaneous nitriﬁcation/denitriﬁcation (SND(Van Mun ch etal.,1996may also occur in the system.Concerning the P removal of the system,biological phos-phate removal processes may occur but were not signiﬁcant because there was no sludge removal and very little sludge precipitation after the run for treatment of municipal sewage.This may partly due to the existence of some ferric chains which were added to precipitate and ﬁx the nylon tissue to the lake bottom,with formation of precipitates of ferric phos-e c o l o g i c a l e n g i n e e r i n g 2 8 ( 2 0 0 6 124–130 129 Table 4 – Proportions of N and P uptake by plants and total removal in the plant-bioﬁlm oxidation ditch treating municipal sewage Date Days ZCa Harvested fresh biomass (g CG ZC 5 September–4 November 5 November–6 January Total or average a Plant uptake (g N CG 5.30 13.03 System removal (kg N CG P Percent of plant uptake N (% P (% P ZC 0.88 0.24 2.79 60 63 123 2200 625 9725 2750 4150 4.85 1.20 24.38 0.72 0.95 37.63 65.45 103.1 7.13 12.78 19.91 0.03 0.02 0.02 0.02 0.01 0.01 ZC: Zizania caduciﬂo ra; CG: Canna generalis. tained for at least 1 year. The actual mechanisms still remain to be identiﬁed. The oxidation ditch has been used for many years worldwide as an economical and efﬁcient wastewater treatment technology that can remove COD, nitrogen and a fraction of the phosphorusefﬁciently. Anaerobic tanks (Liu et al., 2002 and phased isolation ditch systems with intra-channel clariﬁer (Hong et al., 2003 were added to the system to increase the TP removal efﬁciency. The proposed process takes an artiﬁcial process in combination with natural puriﬁcation, transforming the natural lake into the wastewater treatment plant, and could evidently reduce the costs of sewage collection, the landspace requirement and the construction costs compared with the conventional sewage treatment plants. This process could be especially suitable to subtropical regions and to many water bodies in south China and southeast Asia where sewage treatment facilities are not well established. China. The authors are grateful to Dr. P. Christie, Department of Agricultural and Environmental Science, Queen’s University Belfast, UK, and Dr. Y. Ouyang, Department of Water Resources, St. Johns River Water Management District, Palatka, FL, USA, for their valuable suggestions and language corrections. references 4. Conclusions The present study adapted the oxidation ditch on the lake surface for in situ treatment of municipal sewage or polluted lake water in combination with plant bioﬁlms for performing N and P removal, and running experiments at pilot scale for about 1.5 years resulted in the following observations: (1 The system was quite satisfactory and stable for treatment of municipal sewage and polluted lake water in removing COD, NH4 + -N and P. (2 The direct uptake of N and P by plants was negligible in comparison with the totalremoval by the system, but indirect mechanisms via plant root exudates and bioﬁlms merit further studies. (3 The proposed process could dramatically reduce the costs of sewage collection, the land-space requirement and the construction costs compared with conventional sewage treatment plants; might be suitable for treatment of both municipal sewage and polluted lake water; and could lead to the promotion of wastewater treatment in many developing countries. Acknowledgements This study was funded by Department of Science and Technology of Guangdong Province (Grant no. 2004B33301007, American Public Health Association (APHA, 1995. Standards Methods for the Examination of Water and Wastewater, 19th ed. American Public Health Association, Washington, DC. Belmont, M.A., Cantellano, E., Thompson, S., Williamson, M.,S’anchez, A., Metcalfe, C.D., 2004. Treatment of domestic wastewater in a pilot-scale natural treatment system in central Mexico. Ecol. Eng. 23, 299–311. Chen, Y.C., 2003. Bioremediation Engineering of Polluted Environment. Chemical Industry Press, Beijing, p. 304 (in Chinese. Cokgor, S., Kucukali, S., 2004. Oxygen transfer in ﬂow around and over stones placed in a laboratory ﬂume. Ecol. Eng. 23, 205–219. Correll, D.L., 2005. Principles of planning and establishment of buffer zones. Ecol. Eng. 24, 433–439. Coveney, M.F., Stites, D.L., Lowe, E.F., Battoe, L.E., Conrow, R., 2002. Nutrient removal from eutrophic lake water by wetland ﬁltration. Ecol. Eng. 19, 141–159. Deppe, T., Benndorf, J., 2002. Phosphorus reduction in a shallow hypereutrophic reservoir by in-lake dosage of ferrous iron. Water Res. 36, 4525–4534. Hone, A.J., 2000. Phytoremediation by constructed wetlands. In: Terry, N., Banuelos, G. (Eds., Phytoremediation of Contaminated Soil and Water. Lewis Publishers, pp. 13–40. Hong, K.H., Chang, D., Hur, J.M., Han, S.B., 2003. Novel phased isolation ditch system for enhanced nutrient removal and its optimal operating strategy. J. Environ. Sci. Health Part A 38, 2179–2189. Kugaprasatham, S., Nagaoka, H., Ohgaki, S., 1982. Effect of turbulence on nitrifying bioﬁlms at non-limiting substrate conditions. Water Res. 26, 1629–1638. Li, F.X., Xin, Y., Chen, W., 2000. Assessment of eutrophication level of lakes. Chongqing Environ. Sci. 22, 10–11 (in Chinese. Li, F.B., Wu, Q.T., 1997.Domestic wastewater treatment with means of soilless cultivated plants. Chin. J. Appl. Ecol. 8, 88–92 (in Chinese. Liu, J.X., Wang, B.Z., van Groenestijn, J.W., Doddema, H.J., 2002. Addition of anaerobic tanks to an oxidation ditch system to enhance removal of phosphorus from wastewater. J. Environ. Sci. 14, 245–249.130 e c o l o g i c a l e n g i n e e r i n g 2 8 ( 2 0 0 6 124–130 Lu, R.K., 2000. Soil and Agricultural Chemistry Analysis. China Agriculture Press, Beijing (in Chinese. Mitsch, W.J., Horne, A.J., Nairn, R.W., 2000. Nitrogen and phosphorus retention in wetlands—ecological approaches to solving excess nutrient problems. Ecol. Eng. 14, 1–7. Pu, P., Hu, W., Yan, J., Wang, G., Hu, C., 1998. A physico-ecological engineering experiment for water treatment in a hypertrophic lake in China. Ecol. Eng. 10, 179–190. Ray, B.T., 1995. Environmental Engineering. PWS Publishing Company, New York, pp. 299–341. Sooknah, R.D., Wilkie, A.C., 2004. Nutrient removal by ﬂoating aquatic macrophytes cultured in anaerobically digested ﬂushed dairy manure wastewater. Ecol. Eng. 22, 27–42. Van Munch, E.P., Land, P., Keller, J., 1996. Simultaneous nitriﬁcation and denitriﬁcation in bench-scale sequencing batch reactors. Water Sci. Technol. 20,277–284. Wang, C.X., Lin, H., Shi, K.H., 1999. Restoration of polluted river by pure oxygen aeration. Shanghai Environ. Sci. 18, 411–413 (in Chinese. Walpersdorf, E., Neumann, T., Stuben, D., 2004. Efﬁciency of natural calcite precipitation compared to lake marl application used for water quality improvement in an eutrophic lake. Appl. Geochem. 19, 1687–1698.。

3-电气工程及其自动化专业外文文献英文文献外文翻译

3-电气工程及其自动化专业外文文献英文文献外文翻译1、外文原文(复印件)A: Fundamentals of Single-chip MicrocomputerThe single-chip microcomputer is the culmination of both the development of the digital computer and the integrated circuit arguably the tow most significant inventions of the 20th century [1].These tow types of architecture are found in single-chip microcomputer. Some employ the split program/data memory of the Harvard architecture, shown in Fig.3-5A-1, others follow the philosophy, widely adapted for general-purpose computers and microprocessors, of making no logical distinction between program and data memory as in the Princeton architecture, shown in Fig.3-5A-2.In general terms a single-chip microcomputer is characterized by the incorporation of all the units of a computer into a single device, as shown in Fig3-5A-3.ProgramInput& memoryOutputCPU unitDatamemoryFig.3-5A-1 A Harvard typeInput&Output CPU memoryunitFig.3-5A-2. A conventional Princeton computerExternal Timer/ System Timing Counter clock componentsSerial I/OReset ROMPrarallelI/OInterrupts RAMCPUPowerFig3-5A-3. Principal features of a microcomputerRead only memory (ROM).ROM is usually for the permanent,non-volatile storage of an applications program .Many microcomputers and microcontrollers are intended for high-volume applications and hence the economical manufacture of the devices requires that the contents of the program memory be committed permanently during the manufacture of chips . Clearly, this implies a rigorous approach to ROM code development since changes cannot be made after manufacture .This development process may involve emulation using a sophisticated development system with a hardware emulation capability as well as the use of powerful software tools.Some manufacturers provide additional ROM options by including in their range devices with (or intended for use with) user programmablememory. The simplest of these is usually device which can operate in a microprocessor mode by using some of the input/output lines as an address and data bus for accessing external memory. This type of device can behave functionally as the single chip microcomputer from which itis derived albeit with restricted I/O and a modified external circuit. The use of these ROMlessdevices is common even in production circuits where the volume does not justify the development costs of custom on-chip ROM[2];there canstill be a significant saving in I/O and other chips compared to a conventional microprocessor based circuit. More exact replacement for ROM devices can be obtained in the form of variants with 'piggy-back' EPROM(Erasable programmable ROM )sockets or devices with EPROM instead of ROM 。

外文翻译资料原文

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外文翻译及外文原文(参考格式)

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严禁采用专业外语教材文章。

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下页附：外文翻译与原文参考格式英文翻译 (黑体、四号、顶格)外文原文出处：(译文前列出外文原文出处、作者、国籍，译文后附上外文原文)《ASHRAE Handbook —Refrigeration 》.CHAPTER3 .SYSTEM Practices for ammonia 3.1 System Selection 3.2 Equipment3.10 Reciprocating Compressors第3章氨制冷系统的实施3.1 系统选择在选择一个氨制冷系统设计时，须要考虑一些设计决策要素，包括是否采用（1）单级压缩（2）带经济器的压缩（3）多级压缩（4）直接蒸发（5）满液式（6）液体再循环（7）载冷剂。

单级压缩系统基本的单级压缩系统由蒸发器、压缩机、冷凝器、储液器（假如用的话）和制冷剂控制装置（膨胀阀、浮球阀等）。

1997 ASHRAE 手册——“原理篇”中的第一章讨论了压缩制冷循环。

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英文原文(黑体、四号、顶格)英文翻译2（黑体，四号，顶格）外文原文出处：（黑体，四号，顶格）P. Fanning. Nonlinear Models of Reinforced and Post-tensioned Concrete Beams. Lecturer, Department of Civil Engineering, University College Dublin. Received 16 Jul 2001.非线形模型钢筋和后张法预应力混凝土梁摘要:商业有限元软件一般包括混凝土在荷载做用下非线性反应的专用数值模型。

外文文献翻译原文+译文

外文文献翻译原文Analysis of Con tin uous Prestressed Concrete BeamsChris BurgoyneMarch 26, 20051、IntroductionThis conference is devoted to the development of structural analysis rather than the strength of materials, but the effective use of prestressed concrete relies on an appropriate combination of structural analysis techniques with knowledge of the material behaviour. Design of prestressed concrete structures is usually left to specialists; the unwary will either make mistakes or spend inordinate time trying to extract a solution from the various equations.There are a number of fundamental differences between the behaviour of prestressed concrete and that of other materials. Structures are not unstressed when unloaded; the design space of feasible solutions is totally bounded；in hyperstatic structures, various states of self-stress can be induced by altering the cable profile, and all of these factors get influenced by creep and thermal effects. How were these problems recognised and how have they been tackled?Ever since the development of reinforced concrete by Hennebique at the end of the 19th century (Cusack 1984), it was recognised that steel and concrete could be more effectively combined if the steel was pretensioned, putting the concrete into compression. Cracking could be reduced, if not prevented altogether, which would increase stiffness and improve durability. Early attempts all failed because the initial prestress soon vanished, leaving the structure to be- have as though it was reinforced; good descriptions of these attempts are given by Leonhardt (1964) and Abeles (1964).It was Freyssineti’s observations of the sagging of the shallow arches on three bridges that he had just completed in 1927 over the River Allier near Vichy which led directly to prestressed concrete (Freyssinet 1956). Only the bridge at Boutiron survived WWII (Fig 1). Hitherto, it had been assumed that concrete had a Young’s modulus which remained fixed, but he recognised that the de- ferred strains due to creep explained why the prestress had been lost in the early trials. Freyssinet (Fig. 2) also correctly reasoned that high tensile steel had to be used, so that some prestress would remain after the creep had occurred, and alsothat high quality concrete should be used, since this minimised the total amount of creep. The history of Freyssineti’s early prestressed concrete work is written elsewhereFigure1:Boutiron Bridge,Vic h yFigure 2: Eugen FreyssinetAt about the same time work was underway on creep at the BRE laboratory in England ((Glanville 1930) and (1933)). It is debatable which man should be given credit for the discovery of creep but Freyssinet clearly gets the credit for successfully using the knowledge to prestress concrete.There are still problems associated with understanding how prestressed concrete works, partly because there is more than one way of thinking about it. These different philosophies are to some extent contradictory, and certainly confusing to the young engineer. It is also reflected, to a certain extent, in the various codes of practice.Permissible stress design philosophy sees prestressed concrete as a way of avoiding cracking by eliminating tensile stresses; the objective is for sufficient compression to remain after creep losses. Untensionedreinforcement, which attracts prestress due to creep, is anathema. This philosophy derives directly from Freyssinet’s logic and is primarily a working stress concept.Ultimate strength philosophy sees prestressing as a way of utilising high tensile steel as reinforcement. High strength steels have high elastic strain capacity, which could not be utilised when used as reinforcement; if the steel is pretensioned, much of that strain capacity is taken out before bonding the steel to the concrete. Structures designed this way are normally designed to be in compression everywhere under permanent loads, but allowed to crack under high live load. The idea derives directly from the work of Dischinger (1936) and his work on the bridge at Aue in 1939 (Schonberg and Fichter 1939), as well as that of Finsterwalder (1939). It is primarily an ultimate load concept. The idea of partial prestressing derives from these ideas.The Load-Balancing philosophy, introduced by T.Y. Lin, uses prestressing to counter the effect of the permanent loads (Lin 1963). The sag of the cables causes an upward force on the beam, which counteracts the load on the beam. Clearly, only one load can be balanced, but if this is taken as the total dead weight, then under that load the beam will perceive only the net axial prestress and will have no tendency to creep up or down.These three philosophies all have their champions, and heated debates take place between them as to which is the most fundamental.2、Section designFrom the outset it was recognised that prestressed concrete has to be checked at both the working load and the ultimate load. For steel structures, and those made from reinforced concrete, there is a fairly direct relationship between the load capacity under an allowable stress design, and that at the ultimate load under an ultimate strength design. Older codes were based on permissible stresses at the working load; new codes use moment capacities at the ultimate load. Different load factors are used in the two codes, but a structure which passes one code is likely to be acceptable under the other.For prestressed concrete, those ideas do not hold, since the structure is highly stressed, even when unloaded. A small increase of load can cause some stress limits to be breached, while a large increase in load might be needed to cross other limits. The designer has considerable freedom to vary both the working load and ultimate load capacities independently; both need to be checked.A designer normally has to check the tensile and compressive stresses, in both the top and bottom fibre of the section, for every load case. The critical sections are normally, but not always, the mid-span and the sections over piers but other sections may become critical ，when the cable profile has to be determined.The stresses at any position are made up of three components, one of which normally has a different sign from the other two; consistency of sign convention is essential.If P is the prestressing force and e its eccentricity, A and Z are the area of the cross-section and its elastic section modulus, while M is the applied moment, then where ft and fc are the permissible stresses in tension and compression.c e t f ZM Z P A P f ≤-+≤Thus, for any combination of P and M , the designer already has four in- equalities to deal with.The prestressing force differs over time, due to creep losses, and a designer isusually faced with at least three combinations of prestressing force and moment;• the applied moment at the time the prestress is first applied, before creep losses occur,• the maximum applied moment after creep losses, and• the minimum applied moment after creep losses.Figure 4: Gustave MagnelOther combinations may be needed in more complex cases. There are at least twelve inequalities that have to be satisfied at any cross-section, but since an I-section can be defined by six variables, and two are needed to define the prestress, the problem is over-specified and it is not immediately obvious which conditions are superfluous. In the hands of inexperienced engineers, the design process can be very long-winded. However, it is possible to separate out the design of the cross-section from the design of the prestress. By considering pairs of stress limits on the same fibre, but for different load cases, the effects of the prestress can be eliminated, leaving expressions of the form:rangestress e Perm issibl Range Mom entZ These inequalities, which can be evaluated exhaustively with little difficulty, allow the minimum size of the cross-section to be determined.Once a suitable cross-section has been found, the prestress can be designed using a construction due to Magnel (Fig.4). The stress limits can all be rearranged into the form:()M fZ PA Z e ++-≤1 By plotting these on a diagram of eccentricity versus the reciprocal of the prestressing force, a series of bound lines will be formed. Provided the inequalities (2) are satisfied, these bound lines will always leave a zone showing all feasible combinations of P and e. The most economical design, using the minimum prestress, usually lies on the right hand side of the diagram, where the design is limited by the permissible tensile stresses.Plotting the eccentricity on the vertical axis allows direct comparison with the crosssection, as shown in Fig. 5. Inequalities (3) make no reference to the physical dimensions of the structure, but these practical cover limits can be shown as wellA good designer knows how changes to the design and the loadings alter the Magnel diagram. Changing both the maximum andminimum bending moments, but keeping the range the same, raises and lowers the feasible region. If the moments become more sagging the feasible region gets lower in the beam.In general, as spans increase, the dead load moments increase in proportion to the live load. A stage will be reached where the economic point (A on Fig.5) moves outside the physical limits of the beam; Guyon (1951a) denoted the limiting condition as the critical span. Shorter spans will be governed by tensile stresses in the two extreme fibres, while longer spans will be governed by the limiting eccentricity and tensile stresses in the bottom fibre. However, it does not take a large increase in moment ，at which point compressive stresses will govern in the bottom fibre under maximum moment.Only when much longer spans are required, and the feasible region moves as far down as possible, does the structure become governed by compressive stresses in both fibres.3、Continuous beamsThe design of statically determinate beams is relatively straightforward; the engineer can work on the basis of the design of individual cross-sections, as outlined above. A number of complications arise when the structure is indeterminate which means that the designer has to consider, not only a critical section,but also the behaviour of the beam as a whole. These are due to the interaction of a number of factors, such as Creep, Temperature effects and Construction Sequence effects. It is the development of these ideas whichforms the core of this paper. The problems of continuity were addressed at a conference in London (Andrew and Witt 1951). The basic principles, and nomenclature, were already in use, but to modern eyes concentration on hand analysis techniques was unusual, and one of the principle concerns seems to have been the difficulty of estimating losses of prestressing force.3.1 Secondary MomentsA prestressing cable in a beam causes the structure to deflect. Unlike the statically determinate beam, where this motion is unrestrained, the movement causes a redistribution of the support reactions which in turn induces additional moments. These are often termed Secondary Moments, but they are not always small, or Parasitic Moments, but they are not always bad.Freyssinet’s bridge across the Marne at Luzancy, started in 1941 but not completed until 1946, is often thought of as a simply supported beam, but it was actually built as a two-hinged arch (Harris 1986), with support reactions adjusted by means of flat jacks and wedges which were later grouted-in (Fig.6). The same principles were applied in the later and larger beams built over the same river.Magnel built the first indeterminate beam bridge at Sclayn, in Belgium (Fig.7) in 1946. The cables are virtually straight, but he adjusted the deck profile so that the cables were close to the soffit near mid-span. Even with straight cables the sagging secondary momentsare large; about 50% of the hogging moment at the central support caused by dead and live load.The secondary moments cannot be found until the profile is known but the cablecannot be designed until the secondary moments are known. Guyon (1951b) introduced the concept of the concordant profile, which is a profile that causes no secondary moments; es and ep thus coincide. Any line of thrust is itself a concordant profile.The designer is then faced with a slightly simpler problem; a cable profile has to be chosen which not only satisfies the eccentricity limits (3) but is also concordant. That in itself is not a trivial operation, but is helped by the fact that the bending moment diagram that results from any load applied to a beam will itself be a concordant profile for a cable of constant force. Such loads are termed notional loads to distinguish them from the real loads on the structure. Superposition can be used to progressively build up a set of notional loads whose bending moment diagram gives the desired concordant profile.3.2 Temperature effectsTemperature variations apply to all structures but the effect on prestressed concrete beams can be more pronounced than in other structures. The temperature profile through the depth of a beam (Emerson 1973) can be split into three components for the purposes of calculation (Hambly 1991). The first causes a longitudinal expansion, which is normally released by the articulation of the structure; the second causes curvature which leads to deflection in all beams and reactant moments in continuous beams, while the third causes a set of self-equilibrating set of stresses across the cross-section.The reactant moments can be calculated and allowed-for, but it is the self- equilibrating stresses that cause the main problems for prestressed concrete beams. These beams normally have high thermal mass which means that daily temperature variations do not penetrate to the core of the structure. The result is a very non-uniform temperature distribution across the depth which in turn leads to significant self-equilibrating stresses. If the core of the structure is warm, while the surface is cool, such as at night, then quite large tensile stresses can be developed on the top and bottom surfaces. However, they only penetrate a very short distance into the concrete and the potential crack width is very small. It can be very expensive to overcome the tensile stress by changing the section or the prestress。

王德龙外文翻译原文

DC Switching Power Supply Protection Technology1、IntroductionDC switching regulator used in the price of more expensive high-power switching devices,the control circuit is also more complex,In addition,the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Transistors and integrated device tolerance electricity,less heat shocks.Switching Regulators therefore should take into account the protection of voltage regulators and load their own safety.Many different types of circuit protection,polarity protection,introduced here,the program protection,over-current protection,over-voltage protection,under-voltage protection and over-temperature protection ually chosen to be some combination of protection,constitutes a complete protection system.2、polarity protectionDC switching regulator input are generally not regulated DC power supply.Operating errors or accidents as a result of the situation will take its wrong polarity,switching power supply will be damaged.Polarity protection purposes,is to make the switching regulator only when the correct polarity is not connected to DC power supply regulator to work at. Connecting a single device can achieve power polarity protection.Since the diode D to flow through switching regulator input total current,this circuit applied in a low-power switching regulator more suitable.Power in the larger occasion,while the polarity protection circuit as a procedure to protect a link,save the power required for polarity protection diodes,power consumption will be reduced.In order to easy to operate,make it easier to identify the correct polarity or not,collect the next light.3、procedures to protectSwitching power supply circuit is rather complicated,basically can be divided into low-power and high-power part of the control part of the switch.Switch is a high-power transistors,for the protection of the transistor switch is turned on or off power safety,we must first modulator,amplifier and other low-power control circuit.To this end,the boot to ensure the correct procedures.Switching Regulators generally take the input of a small inductor,the input filter capacitor.Moment in the boot,filter capacitor will flow a lot of surge current,the surge current can be several times more than the normal input current. Such a large surge current may contact the general power switch or relay contact melting,and the input fuse fuse.In addition,the capacitor surge current will damage to shorten the life span of premature damage.To this end,the boot should be access to a current limiting resistor,through the current limiting resistor to capacitor charging.In order not to make the current limiting resistor excessive power consumption,thus affecting the normal switching regulator,and the transient process in the boot after a short period then automatically relays it to DC power supply directly to the switching regulator power supply.This circuit switching regulator called a"soft start"circuit.Switching regulator control circuit of the logic components required or op-amp auxiliary power supply.To this end,the auxiliary power supply must be in the switch circuit. This control circuit can be used to ensure the boot.Normal boot process is:to identify the polarity of input power,voltage protection procedures→boot→auxiliary power supply circuit and through current limiting resistor R of the switching regulator input capacitor C→charge modulation switching regulator circuit,→short-circuit current limiting resistor stability switching regulator.In the switching regulator,the machines just because the output capacitance,and charge to the rated output voltage value of the need for a certain period of time.During this time, sampling the output amplifier with low input voltage sampling,closed-loop regulation characteristics of the system will force the switching of the transistor conduction time lengthened,so that switching transistor during this period will tend to continuous conduction, and easily damaged.To this end,the requirements of this paragraph in the boot time,the switch to switch the output modulation circuit transistor base drive signal of the pulse width modulation,can guarantee the switching transistor by the cut-off switches are becoming more and more normal state,therefore the protection of the setting up of a boot to tie in with the soft start.4、over-current protectionWhen the load short-circuit,overload control circuit failure or unforeseen circumstances,such as would cause the flow of switching voltage regulator transistor current is too large,so that increased power tubes,fever,if there is no over-current protection device, high power switching transistor may be damaged.Therefore,the switching regulator in the over-current protection is commonly used.The most economical way is to use simple fuse. As a result of the heat capacity of small transistors,general fuse protection in general can not play a role in the rapid fuse common fuse.This method has the advantage of the protectionof vulnerable,but it needs to switch transistor in accordance with specific security requirements of the work area to select the fuse specifications.This disadvantage is over-current protection measures brought about by the inconvenience of frequent replacement of fuses.Linear voltage regulator commonly used in the protection and current limiting to protect the cut-off in the switching regulator can be applied.However,according to the characteristics of switching regulators,the protection circuit can not directly control the output transistor switches,and overcurrent protection must be converted to pulse output commands to control the modulator to protect the transistor switch.In order to achieve over-current protection are generally required sampling resistor in series in the circuit,this will affect the efficiency of power supply,so more for low-power switching regulator of occasions.In the high-power switching power supply,by taking into account the power consumption should be avoided as far as possible access to the sampling resistor.Therefore, there will usually be converted to over-current protection,and under-voltage protection.5、over-voltage protectionSwitching regulator's input over-voltage protection,including over-voltage protection and output over-voltage protection.Switching regulator is not used in DC power supply voltage regulator and rectifier,such as battery voltage,if too high,so switching regulator is not working properly,or even damage to internal devices,therefore,it is necessary to use the input over-voltage protection ing transistors and relays protection circuit.In the circuit,when the input DC power supply voltage higher than the voltage regulator diode breakdown voltage value,the breakdown voltage regulator tube,a current flowing through resistor R,so that V turn-on transistor,relay,normally closed contact off open,cut off the input.Voltage regulator voltage regulator which controls the value of Vz= ESrmax-UBE.The polarity of input power with the input protection circuit can be combined with over-voltage protection,polarity protection constitute a differential circuit and overvoltage protection.Output over-voltage protection switching power supply is essential.In particular,for the5V output of the switching regulator,it is a lot of load on a high level of integration of the logic device.If at work,switching regulator sudden damage to the switch transistor,the output potential may be increased immediately to the importation of non-regulated DC power supply voltage value,causing great loss monly used method isshort-circuit protection thyristor.The simplest over-voltage protection circuit.When the output voltage is too high,the regulator tube breakdown triggered thyristor turn-on,the output short-circuit,resulting in over-current through the fuse or circuit protective device to cut off the input to protect the load.This circuit is equivalent to the response time of the opening time of thyristor is about5~10μs.The disadvantage is that its action is fixed voltage,temperature coefficient,and action points of instability.In addition,there is a voltage regulator control parameters of the discrete,model over-voltage start-up the same but has different values,difficult to debug.Esc a sudden increase in output voltage, transistors V1,V2conduction,the thyristor conduction.Reference voltage Vz by type.6、under-voltage protectionOutput voltage below the value to reflect the input DC power supply,switching regulator output load internal or unusual occurrence.Input DC power supply voltage drops below the specified value would result in switching regulator output voltage drops,the input current increases,not only endanger the switching transistor,but also endanger the input power.Therefore,in order to set up due to voltage protection.Due to simple voltage protection.When no voltage regulator input normal,ZD breakdown voltage regulator tube, transistors V conduction,the relay action,contact pull-in,power-switching regulator.When the input below the minimum allowable voltage value,the regulator tube ZD barrier,V cut-off,contact Kai-hop,switching regulator can not work.Internal switching regulator,as the control switch transistor circuit disorders or failure will decrease the output voltage;load short-circuit output voltage will also decline.Especially in the reversed-phase step-up or step-up switching regulator DC voltage of the protection due to over-current protection with closely related and therefore more important.Implementation of Switching Regulators in the termination of the output voltage comparators.Normally,there is no comparator output,once the voltage drops below the allowable value in the comparator on the flip,drive alarm circuit;also fed back to the switching regulator control circuit,so that switching transistor cut-off or cut off the input power.7、over-temperature protectionSwitching regulator and the high level of integration of light-weight small volume,with its unit volume greatly increased the power density,power supply components to its workwithin the requirements of the ambient temperature is also a corresponding increase. Otherwise,the circuit performance will deteriorate,premature component failure.Therefore, in high-power switching regulator should be set up over-temperature protection.Relays used to detect the temperature inside the power supply temperature,when the internally generated power supply overheating,the temperature of the relay on the action,so that whole circuit in a warning alarm,and the realization of the power supply over-temperature protection.Temperature relay can be placed in the vicinity of the switching transistor,the general high-power tube shell to allow the maximum temperature is75℃, adjust the temperature setting to60℃.When the shell after the temperature exceeds the allowable value to cut off electrical relay on the switch protection.Semiconductor switching device thermal"hot thyristor,"in the over-temperature protection,played an important role. It can be used as directed circuit temperature.Under the control of p-hot-gate thyristor (TT102)characteristics,by RT value to determine the temperature of the device turn-on,RT greater the temperature the lower the turn-on.When placed near the power switching transistor or power device,it will be able to play the role of temperature instructions.When the power control the temperature of the shell or the internal device temperature exceeds the allowed value,the heat conduction thyristor on,so that LED warning light.If the optocoupler with,would enable the whole circuit alarm action to protect the switching regulator.It can also be used as a power transistor as the over-temperature protection,crystal switch the base current by n-type gate control thyristor TT201thermal bypass,cut-off switch to cut off the collector current to prevent overheating.8、ConclusionDiscussed above in the switching regulator of a variety of conservation,and introduces a number of specific ways to achieve.Of a given switching power supply is concerned,but also protection from the whole to consider the following points:1)the switching regulator used in the switching transistor in the DC security restrictions on the work of regional work.The transistor switches selected by the manual available transistors get DC safe working area.According to the maximum collector current to determine the input value of over-current protection.However,the instantaneous maximum value should be converted to the average current.At rated output current and output voltage conditions,the switch of the dynamic load line does not exceed a safe working area DC maximum input voltage,input over-voltage protection is the voltage value.2)the switching regulator output limit given by the technical indicators within.Work within the required temperature range,the switching regulator's output voltage,the lower limit of the output is off,due to the voltage value of voltage protection.Over-current protection can be based on the maximum output current to determine.False alarm in order not to protect the value of a certain margin to remain appropriate.3)from the above two methods to determine the protection after the power supply device in accordance with the needs of measures to determine the alarm.Measures the general alarm sound and light alarm two police.Voice of the police applied to more complex machines,power supply parts and do not stand out in a place,it can give staff an effective warning of failure;optical Police instructions can be eye-catching and fault alarm and pointed out that the fault location and type.Protection measures should be protected as to determine the location.In the high-power,multi-channel power supply,always paying,DC circuit breakers,relays,etc.high-sensitivity auto-protection measures,to cut off the input power supply to stop working the system from damage.Through the logic control circuit to make the appropriate program cut-off switch transistor is sensitive it is convenient and economic.This eliminated large,long response time,the price of your high-power relay or circuit breaker.4)the power of putting in the protection circuit will be affected after the reliability of the system,for which want to protect the reliability of the circuit itself is higher in order to improve the reliability of the entire power system,thereby increasing its own power supply MTBF.This requires the protection of strict logic,the circuit is simple,at least components, In addition to the protection circuit should also be considered a failure of maintenance of their difficulty and their power to protect the damage.Therefore,we must be comprehensive and systematic consideration of a variety of switching power supply protection measures to ensure the normal operation of switching power supplies and high-efficiency and high reliability.。

外文翻译--最佳人才评价措施

外文文献翻译译文一、外文原文原文：Best Practices in Talent AssessmentBy Dan Harrison, Ph.DAssessing people for jobs is the most important task of any organization. The quality of assessment ultimately determines the performance of new hires as well as the ability of the organization to effectively develop employees. It affects every important aspect of the organization’s success including management effectiveness, sales volume, customer retention and productivity. Assessment is not merely one of the functions of the Human Resource Department. It is the essential foundation for effective talent acquisition and talent management.High quality assessment used at the point of hire enables you to have the greatest impact on performance and productivity in your organization. High quality assessment of applicants during the recruitment process results in less time and money spent on training and developing employees. This enables management to focus on important strategic issues. Good assessment reduces training costs, minimizes losses due to poor decisions, increases employee retention and can even provide a foundation for better teamwork.Effective assessment also provides huge benefits for employee development. Assessing existing employees makes employee development much more efficient and effective. Good assessment can enable employees to clearly understand their performance in relationship to the job requirements. This can be a great boost to employee motivation. It can also provide managers with a means of pinpointing the development areas that will provide the greatest impact on performance. Harrison Assessment s™ Talent Solutions System even goes a step further by providing managers and coaches with effective tools for encouraging and enlisting topperformance as well as providing guidelines for developing specific job success behaviors. In addition, reports also help employees to better understand how to apply their strengths for their career development. These are key areas that promote talent retention and motivation.Formulating the success factors for the specific jobThe first challenge of effective assessment is to fully understand the job and formulate the success factors. Without a clear understanding of the job and the job success factors, assessment cannot be effective. It is essential to understand the tasks performed, the responsibilities, the key performance factors and the requirements that relate to effective performance. The Harrison Assessments System provides a comprehensive list of typical factors for each specific job as well as additional optional factors that can be included.Assessing a person against job factors is much more challenging and much more complex than merely assessing a person. It is essential to determine the key success factors for the specific job, including how important each of those factors are in relationship to each other. In addition, it is essential to determine how having different levels of a job success factor affects the overall performance. This is a complex process requiring sophisticated calculations, which can best be achieved through extensive job research and computer technology.There are two basic categories of job requirements: Eligibility and Suitability. Eligibility factors include previous experience, education, certifications, skills, abilities and reference checks. Suitability factors include attitude, motivation, integrity, interests, work preferences, fit with the company culture and fit with the manager.Assessing Levels of EligibilityMany organizations assess eligibility factors by setting minimum requirements. However, few organizations systematically formulate eligibility factors in order to score each applicant’s level of eligibility. It is not enough to ascertain that the applicant meets the minimum requirements. All that does is eliminate the people whodon’t meet the requirements. It does nothing to assess the remaining people who do meet the minimum requirements. Therefore, it is essential to quantify each candidate’s level of eligibility. This is the only way in which you can effectively compare candidates to each other and to integrate the eligibility score with the behavioral score.First, you need to determine what the eligibility factors are. For example, you may require previous experience in the same job, previous experience doing similar tasks that the job requires, certain educational levels, or skills such as typing speed or the ability to use software packages. The Harrison Assessments enables you to select from a comprehensive list factors and then weight them according to how important they are.By using gradient scoring, you ar e able to quantify the person’s experience and obtain a score for each factor. By weighting the factors in relationship to each other, you are able to obtain an overall eligibility score.Assessing Levels of SuitabilityFor most jobs, suitability factors are about 50% of the job success factors. Therefore, effectively measuring suitability is an essential part of assessment. However, suitability is much more difficult to measure than eligibility. The first challenge is to determine which suitability factors relate to job success for a particular job. However, even when that is determined, to accurately assess job suitability you also need to formulate how different levels of each suitability factor will impact job success. For example, you may determine that self-motivation is an important factor for job success for a particular job. But you still need to quantify how each level of self-motivation will impact success in order to calculate the results. For example, if the person scores a 5 out of 10 on self motivation, you need a means to designate how that will impact overall job success for the specific job. For some jobs, the more self-motivation the person has the better. However, for other jobs, a moderate level is enough and high levels do not relate to increased performance. Each level of each factor needs to be scored according to its impact on performance. That is why HAcontains significant research regarding suitability factors and their impact on performance for different job types and for different jobs. Without this, it is nearly impossible to assess behavior effectively. Suitability factors are behavioral and are much more difficult for people to change than eligibility factors. This makes it even more important to accurately assess behavior during the recruitment process. Most organizations hire people for their eligibility and then try to develop their suitability. And in many cases fire them for their lack of suitability. Since behavior is fundamentally more difficult to change than eligibility, it is better to hire people who already have the suitability for the job. To illustrate different aspects of suitability, here are some examples of job behavior factors that could be relevant to a specific job. These are just a small sample of more than one hundred important suitability factors that could relate to job success.Using Interviews to Assess Job BehaviorIn the past, interviews have been used as the primary means assess attitude, motivation, and job behavior. However, even if interviewers are extremely intuitive, there are many reasons why accurately assessing job behavior using only an interview process is nearly impossible.1. Interviewers do not have access to a real behavioral success formula.There are dozens of behavioral factors that either promote success or inhibit success for any one job. Interviewers rarely have access to a job formula that identifies the behavioral success factors, weights the success factors against each other. And formulates how different levels of these success factors impact job performance.2. Even if the interviewer has access to such a formula, the interviewer would need to accurately assess specific levels of each applicant’s behavior for each of the job success factors.3. Some people are skillful at being interviewed. However, being skillful at an interview usually does not relate to job success and therefore it often confuses the interviewer into thinking that such skillfulness will translate to job success. To makeinterviewing even more difficult, job applicants now have access to extensive information and training related to how answer specific questions and how to “ace” the interview.4. The interviewee aims to tell the interviewer what he/she thinks will be viewed as the best response. The interviewer aims to determine how much of what the person is saying reflects genuine attitudes and behavior and how much is related to just trying to get the job. This in itself is extremely difficult to resolve in the short period of the interview.5. Interviewers are biased. Research clearly shows that interviewers routinely give favorable responses to people who are similar to themselves, and less favorable responses to people who are different from themselves. In the end, the result is very likely to come down to how well the interviewer likes the candidate rather than how well the candidate fits the behavioral requirements of the job.Many interviewers claim insights into the personality of applicants and certainly some interviewers are quite perceptive. However, predicting job success is an entirely different matter. It is not sufficient to perceive a particular quality of a person. Rather, the interviewer must be able to accurately assess themagnitude of each of dozens of qualities in relationship to a complex formula of behavioral requirements for a particular job. This is nearly an impossible task without the aid of significant research and tools.Assessment research shows that interviewing has a moderate ability to predict job success. However, this doesn’t mean that interviewers can predict job behavior. The moderate ability to predict job success comes as a result of exploring the candidate’s resume, previous experience, education, and job knowledge rather than the interviewer’s ability to predict job behavior. If you believe that interviewer can predict job behavior, I suggest you try an experiment. Have your interviewers conduct the interview without ever seeing the resume and without discussing past experience, education or skills. Then have them write down their job success prediction. Later,you can compare this prediction to actual job performance. In fact, conducting interviews in this way would be so difficult that I doubt anyone would even attempt it. In comparison, an effective job behavior assessment can obtain a moderate level of predictive accuracy for job performance on its own, without any knowledge of eligibility or any interview. This is a significant achievement because the eligibility has not been factored into the prediction. However, the value of job behavior assessment is much greater than simply its ability to predict job success on its own. By using an effective job behavior assessment at the interview, the interviewer obtains the tools to transform the interview into a genuine discussion about the person’s real fit for the job as well as the person’s likely level of job satisfaction. Thus, using the results of a behavioral assessment during the interview process is greatly increases the ability to predict job behavior. When this approach is combined with a systematic assessment of eligibility, the ability to predict job performance is increased even further.Summarizing the Value and Challenges of AssessmentEffectively assessing both job behavior and job eligibility is the essential foundation necessary to hire, retain and develop top talent. Assessment needs to quantify levels of eligibility as well as job success behaviors. To do so requires a job success formula. Interviewing does not effectively assess job behavior unless it is conducted using a job behavior assessment. Effective job behavior assessment requires the ability to measure more than 100 traits, a questionnaire that is work-focused, the ability to detect false answers and/or self-deception, a specific job success formula derived from performance research and clear reports that do not require interpretation. Harrison Assessments meets all of the standards mentioned above providing a powerful tool for assessment. It enables you to build a strong foundation for your talent selection, retention and development.HA is the only assessment method that:Uses a full spectrum of behavioral assessments, including personality, interests, work environment preferences and task preferences.Uses a high-tech questionnaire that provides the equivalent of a full day of testing in only 30 minutes.Uses a technological consistency detector that provides an extremely reliable validation of the authenticity of the answers.Can be effectively applied without professional interpretation.Uses the power of paradox to decipher subtleties and complexities of personality related to job performance.Offers complete customization to specific job requirements.Offers a complete research database of success traits for different position types.Delivers cost-effective high correlation with actual job performance.资料来源：By Dan Harrison, Ph.D. Best Practices in Talent Assessment. Harrison Assessments Int'l ，2008：P10-P11二、翻译文章译文：最佳人才评价措施By Dan Harrison, Ph.D不论任何组织，评估人才工作是最重要的任务。

应收账款【外文翻译】

外文文献翻译一、外文原文原文：Accounts Receivable IssuesFor many companies, the accounts receivable portfolio is its largest asset. Thus, it deserves special care and attention. Effective handling of the portfolio can add to the bottom line, while neglect can cost companies in unseen losses.Accounts Receivable Strategies to Energize the Bottom LineDon’t be surprised to find the big shots from finance suddenly looking over your shoulder questioning the ways your credit department operates. Accounts receivable has become the darling of those executives desperate to optimize working capital and improve their balance sheet.Here’s a roundup of some of the tactics that have been collected from the best credit managers to squeeze every last cent out of their accounts receivable portfolio: ·Have invoices printed and mailed as quickly as possible. Most customers start the clock ticking when the invoice arrives in their offices. The sooner you can get the invoice to them, the sooner they will pay you. While this strategy will not affect days sales outstanding(DSO),it will improve the bottom line.·Look for ways to improve invoice accuracy without delaying the mail date.·Offer more stringent terms where appropriate in your annual credit reviews and with new customers. Consider whether shorter terms might be better for you company.·Offer financial inducements to customers who agree to pay your invoices electronically.·If you have not had a lockbox study performed in the last few years, have one done to determine your optimal lockbox location.·With customers who have a history of paying late, begin your collection effortsbefore the due date. Call to inquire whether they have the invoice and if everything is in order. Resolve any problems quickly at this point.·If you have been giving a grace period to those taking discounts after the discount period, reduce or eliminate it.·Resolve all discrepancies quickly so payment can be made promptly.·If a customer indicates it has a problem with part of an invoice, authorize partial payments.·Keep a log of customer problems and analyze it once a month to discover weaknesses in your procedures that cause these quandaries.·Apply cash the same day the payment is received. Collectors can then spend their time with customers who have not paid rather than annoying ones who have already sent their payment.·Deal with a bank that makes lockbox information available immediately by fax, or preferably, online. Then when a customer claims it has made a payment , the collector will be able to verify this.·Look into ways to accept P-cards from customers placing small orders and those who cannot be extended credit on open account terms.·Benchmark department and individual collectors’ performance to pinpoint those areas and individuals in need of additional training.Review your own policies and procedures to determine if there are any areas that could be tweaked to improve cash flow. Then, when the call comes from executive quarters, you will be ready, and they will be hard pressed to find ways that you fell down on the job.Dealing with Purchase OrdersLeading credit managers have learned to pay attention to the purchase orders that their companies receive. Specifically, they want to ensure that the purchase order accepted by the salesperson does not include clause that will ultimately cause trouble for their companies, or even legal difficulties later on. Realistically, the salesperson should have caught the problem, but he or she rarely does. When the customer doesn’tpay due to one of these techn icalities, it’s not the salesperson who will get blamed.To help avoid a purchase order disaster, credit professionals can take the following steps:1．Simply read the purchase order. Vendors often slip clauses into purchase orders that you would never agree to. One favorite is to include a statementsaying the seller will be paid as soon as its customer pays the buyer. This is arisk few companies are willing to tolerate.2．Prioritize attachments. Typically, buyers write purchase orders that contain attachments. These include drawings, specifications, supplementary termsand conditions for work done on company premises, or safety rules for thesupplier.When including attachments, it is recommended that one of them be a listof priorities to guard against any inconsistencies in the documents. Thepurchase order should “clearly reference all the attachments, and there shouldbe a recitation as to which attachments are controlling over the others.” In theevent of any inconsistency between or among these documents, the purchaseorder shall be controlling over any attachments, and the attachments shall beinterpreted using the priority listed.3．Take care when reference is made to a buyer’s documents in the purchase order. There are likely to be both helpful and harmful statements in thosedocuments that reference the buyer’s material. The buyer may have printedits own terms and conditions on the back of a document. By referring to thedocument in the purchase order, you may inadvertently refer not only to theprice, but also to terms and conditions, which may include warrantydisclaimers and limitations of remedies that your company does not intend togive.Instead, the recommendation is not to refer to the buyers’ documents.Insist that the information is specified in the purchase order. If this is notpractical, the following language might work:” Any reference to thepurchaser’s quotation contained in this purchase order is a reference forconvenience only, and no such reference shall be deemed to include any ofthe purchaser’s standard terms and conditions of sale. The seller expresslyrejects anything in any of the buyer’s documents that is inconsistent with theseller’s standard terms and conditions.”Another favorite is to include terms and conditions on the back of thepurchase order written in very small print and a pale (almost undecipherable)color.4．Be careful of confirming purchase orders. Often, buyers will place orders via telephone, only to later confirm them with a written purchase order. In oralcontracts, the buyer will often want the purchase order to be more than justan offer. Therefore, the buyer will try to show on the purchase order that it isa confirming purchase order and cement the oral contract made over thephone. If the buyer does so, the confirming purchase order will satisfy theUniform Commerical Code (UCC) requirement of a written confirmationunless the other side objects to it within ten days.More than one cunning purchaser has slipped terms into a confirmingpurchase order that were nothing like those agreed to orally. Don’t fall intothe trap of assuming that the confirming purchase order confirms what wasactually said on the phone.Credit professionals who take these few extra steps with regard to purchase orders will limit their troubles.Quality of Accounts Receivable: Days Sales OutstandingMany credit professionals are measured on their effectiveness by reviewing the accounts receivable portfolio. The most common measurement is the length of time a sale stays outstanding before being paid. The Credit Research Foundation (CRF) defines DSO as the average time in days that receivables are outstanding. It helps determine if a change in receivables is due to a change in sales, or to another factor such as a change in selling terms. An analyst might compare the day’s sales in receivables with the company’s credit terms as an indication of how efficiently thecompany manages its receivables. Days sales outstanding is occasionally referred to as days receivable outstanding, as well. The formula to calculate DSO is:365e Re Sales t N Annual ceivablesGrossQuality of Accounts Receivable: Collection Effectiveness IndexSome feel that the quality of the portfolio is dependent to a large extent on the efforts of the collection staff. This is measured by the collection effectiveness index (CEI). The CRF says this percentage expresses the effectiveness of collection efforts over time. The closer to 100% the ratio gets, the more effective the collection effort. It is a measure of the quality of collection of receivables, not of time. Here’s the formula to calculate the CEI:Daysor Months of Number N ceivables Current Ending N Sales Credit ceivables Beginning ceivablesTotal Ending N Sales Credit ceivables Beginning =⨯-+-+100Re )(Re Re )(ReQuality of Accounts Receivable: Best Possible Days Sales OutstandingMany credit professionals find fault with using DSO to measure theirperformance. They feel that a better measure is one based on average terms based on customer payment patterns. The CRF says that this figure expresses the best possible level of receivables. The CRF believes this measure should be used together with DSO. The closer the overall DSO is to the average terms based on customer payment patterns (best possible DSO [BPDSO])，the closer the receivables are to the optimal level. The formula for calculating BPDSO is:AnalyzedPeriod for Sales Credit Analyzed Period in Days of Number ceivables Current ⨯ReBad-Debt ReservesInevitably, no matter how good the credit professional, a company will have a customer that does not pay its debts. Most companies understand that bad debts are simply part of doing business and reserve for bad debts. In fact, many believe that acompany with no bad debts is not doing a good job. The reason that being that if the company loosened its credit terms slightly, the company would greatly increase its sales and, even after accounting for the bad debts, its profits. Thus, most companies plan for bad debt, monitor it, and periodically, depending on the company’s outlook, revise projections and credit policy to allow for an increase or decrease.For example, as the economy goes into a recession, most companies will experience an increase in bad debts if their credit policy remains static. So, in light of declining economic conditions, companies should either increase their bad-debt reserves or tighten the credit policy. Similarly, if the economy is improving, a company would take reverse actions, either decreasing the reserve for bad debts or loosening the credit policy.Many companies take advantage or a favorable economy to expand their customer base. They might simultaneously increase the bad-debt reserve and loosen credit policy. Obviously, these decisions are typically made at a fairly high level. Other factors will also come into play in establishing a bad-debt reserve. Industry conditions are key and can often be quite different than the state of the economy. This is especially true when competition comes from foreign markets.There is no one set way to calculate the reserve for bad debts. Many simply take a percentage of sales or outstanding accounts receivable, or they make some other relatively uncomplicated calculation.How to Reduce Your Bad-Debt Write-OffsMost credit and collection professionals would love to be able to brag about having no bad-debt write-offs. Few can. While a goal of reducing the amount of bad debt write-offs to zero might be unrealistic in most industries, keeping that number as low as possible is something within the control of today’s credit managers. The following seven techniques will help you keep your numbers as low as possible:1.Call early. Don’t wait until the ac count goes 30 or even 60 days past duebefore calling customers about late payments. Such delays can mean that, in the case of a financially unstable company, a second and perhaps even a thirdshipment will be made to a customer who ultimately will pay for naught. Some professionals even call a few days before the payment is due to ensure that everything is in order and the customer has everything it needs to make a timely payment. By beginning your calling campaign as early as possible, it is possible o uncover shaky situations. Even if payment is not received for the first delivery, future order are not accepted, effectively reducing bad-debt write-offs.municate, communicate, communicate. Keep the dialogue open with everyone involved. This not only includes your customers, but the sales force as well. In many cases, they are in a better position than the credit manager to know when a customer is on thin ice. With good lines of communication between sales and credit, it is possible to avoid taking some of those orders that will ultimately have to be written off.3.Follow up, follow up, follow up. Continual follow up with customers is important, whether you’re trying to collect on a timely basis or attempting to avoid a bad-debt write-off. If the customer knows you will call every few days or will be calling to track the status of promises made, it is much more likely to pay. This can also be the case of the squeaky wheel getting the grease, or in this case the money, when cash is tight.4.Systematize. Many collection professionals keep track of promises and deadlines by hand, on a pad or calendar. Items tend to fall through the cracks with this approach. Invest some money either in prepackaged software or in developing your own in-house, and the likelihood of losing track of customers diminishes. Some accounting programs have a tracking capability that many have not taken the time to learn. If your software has such a facility, use it.5.Specialize. Set up a group of one or more individuals who do nothing but try to collect receivables that are overdue. By having experts on staff to handle such work, you will improve your collection rate and speed.6.Credit hold. Putting customers on credit hole early in the picture will sometimes entice a payment from someone who really had no intention of paying you. This technique is particularly effective with customers who rely heavily onyour product and would be hard put to get it elsewhere. Of course, if you sell something that many other vendors sell as well, putting a potentially good customer on hold could backfire.7.Small claims court. Some credit professionals have had great success incollecting smaller amounts by taking the customer to small claims court. The limits for such actions vary by state but can be as high as $10,000.While these techniques will not necessarily squeeze money from a bankrupt client, they will help you get as much as possible as soon as possible from as many of your customers as possible. This can be especially important in avoiding preference actions with clients who eventually do file. The quicker you get the clock ticking, the more likely you are to be able to avoid preference claims.Source: Mary S. Schaeffer, 2002, Essentials of Credit, Collections, and Accounts Receivable, John Wiley & Sons, Inc.( October 01, 2002 ):pp81-102.二、翻译文章译文：应收账款对许多公司来说，应收账款是其最大的资产。

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Project Management ProcessDurgesh BurdeAbstract:There are the rules of project management. Project management skills are indispensable for project managers, and other managers who control intricate actions and responsibilities, because intricate responsibilities are projects. Project management skills are necessary for any intricate responsibility, where diverse results are feasible, requiring plan and assess alternatives, and organizing actions and assets to deliver an outcome. Projects arrive in all forms and dimensions, from the little and simple to extremely big and highly intricate. Project management may be concerned with everything such as:- public, products, finance, buildings and premises, acquisition, services, purchasing, resources, construction, plant and equipment, training, culture, divestment, storage, distribution, logistics, IT and communications, staffing and management, administration, sales, selling, marketing, human resources, etc. Project management, for projects large or small, should follow the simple process:Project management process1.Detailed requirement for the project.2.Plan the project - time, team, activities, resources, and financials.3.Correspond the project plan to the project group.4.Consent and allot project actions.5.Control, encourage, notify, promote, and facilitate the project team.6.Verify, assess, evaluate project development; regulate project procedure, andnotify the project members and others.7.Finish project; evaluation and report on project performance; Admire and thanksto the project members.1. Detailed requirement for the projectFrequently called the project 'terms of reference', the project requirement should be an exact depiction of what the project aspires to accomplish, and the criteria and flexibilities concerned, its factors, scope, range, outputs, sources, participants, budgets and timescales.The project manager must discuss with others and then consent the project requirement with superiors, or with relevant authorities. The requirement may engage several drafts before it is agreed. A project requirement is essential in that it creates a measurable accountability for anyone wishing at any time to assess how the project is going, or its success on completion. Project terms of reference also provide an essential discipline and framework to keep the project on track, and concerned with the original agreed aims and parameters. A properly formulated and agreed project requirement also protects the project manager from being held to account for issues that are outside the original scope of the project or beyond the project manager's control.This is the step to agree special circumstances or exceptions with those in authority. Once you have published the terms of reference you have created a very firm set of expectations by which you will be judged. So if you have any concerns, or want to renegotiate, now's the time to do it.The largest projects can require several weeks to produce and agree project terms of reference. Most normal business projects however require a few days thinking and consulting to produce a suitable project requirement. Establishing and agreeing a project requirement is an important process even if your task is simple one.An outline for a project requirement:1.Describe purpose, aims and deliverables.2.State factors (timescales, budgets, range, scope, territory, authority).3.State people involved and the way the team will work (frequency of meetings,decision-making process).4.Establish 'break-points' at which to review and check progress, and how progressand results will be measured.2. Plan the project - time, team, activities, resources, and financials.Plan the various steps and tasks of the project. A valuable tip is to work backwards from the end aim, identifying all the things that need to be put in place and done, in reverse order. First, idea generation will help to gather most of the points and issues. For complex projects, or when you lack experience of the issues, involve others in the idea generation process. Thereafter it is a question of putting the issues in the right order, and establishing relationships and links between each issue. Complex projects will have a number of tasks running in parallel. Some parts of the project will need other parts of the project to be completed before they can begin or progress. Some projects will require a feasibility step before the completion of a detailed plan.a) Project timescalesMost projects come in late - that is just the way it is - so do not plan a timescale that is over-ambitious. Preferably, plan for some adversaries. If you have been given a fixed deadline, plan to meet it earlier, and work back from that earlier date. Build some slippage or leeway into each phase of the project. Err on the side of caution where you can. Otherwise, you will be making a rod for your own back.b) The project teamAnother important part of the planning stage is picking your team. Take great care, especially if you have team-members imposed on you by the project brief. Selecting and gaining commitment from the best team members - whether directly employed, freelance, contractors, suppliers, consultants or other partners - is crucial to the quality of the project, and the ease with which you are able to manage it. Generally try to establish yourteam as soon as possible. Identifying or appointing one or two people even during the terms of reference stage is possible sometimes. Appointing the team early maximizes their ownership and buy-in to the project, and maximizes what they can contribute. But be very cautious of appointing people before you are sure how good they are, and not until they have committed themselves to the project upon terms that are clearly understood and acceptable. Do not imagine that teams need to be full of paid and official project team members. Some of the most valuable team members are informal advisors, mentors, helpers, who want nothing other than to be involved and a few words of thanks. Project management on a tight budget can be a lonely business - get some help from good people you can trust, whatever the budget.To plan and manage large complex projects with various parallel and dependent tasks you will need to put together a 'Critical Path Analysis' and a spreadsheet on MS Excel or equivalent. Critical Path Analysis will show you the order in which tasks must be performed, and the relative importance of tasks. Some tasks can appear small and insignificant when they might actually be hugely influential in enabling much bigger activities to proceed or give best results. A Gantt chart is a useful way of showing blocks of activities over time, at a given cost, and for managing the project and its costs along the way.Various project management software is available, much of which is useful, but before trying it, you should understand and concentrate on developing the pure project management skills, which are described in this process. The best software in the world will not help you if you cannot do the key things.c) The project 'critical path analysis''Critical Path Analysis' sounds very complicated, but it's a very logical and effective method for planning and managing complex projects. This is how to create a critical path analysis. As an example, the project is a simple one - making a fried breakfast.First note down all the issues (resources and activities in a rough order):Assemble crockery and utensils, assemble ingredients, prepare equipment, make toast, fry sausages and eggs, grill bacon and tomatoes, lay table, warm plates, serve.Note that some of these activities must happen in parallel. That is to say, if you tried to make a fried breakfast by doing one task at a time, and one after the other, things would go wrong. Certain tasks must be started before others, and certain tasks must be completed in order for others to begin. The plates need to be warming while other activities are going on. The toast needs to be toasting while the sausages are frying, and at the same time the bacon and sausages are under the grill. The eggs need to be fried last. A critical path analysis is a diagrammatical representation of what needs done and when. Timescales and costs can be applied to each activity and resource. Here's the critical path analysis for making a fried breakfast:This critical path analysis example below shows just a few activities over a few minutes. Normal business projects would see the analysis extending several times wider than this example, and the time line would be based on weeks or months. It is possible to use MS Excel or a similar spreadsheet to create a critical path analysis, which allows financial totals and time totals to be planned and tracked. Various specialized project management software enable the same thing. Beware however of spending weeks on the intricacies of computer modeling, when in the early stages especially, a carefully hand drawn diagram - which requires no computer training at all - can put 90% of the thinking and structure in place.d) Gantt chartsGantt Charts are extremely useful project management tools. You can construct a Gantt Chart using MSExcel or a similar spreadsheet. Every activity has a separate line. Create a time-line for the duration of the project (the breakfast example shows minutes, but normally you would use weeks, or for very big long-term projects, months). You can colour code the time blocks to denote type of activity (e.g. intense, watching brief, directly managed, delegated and left to run, etc.) You can schedule review and break points. At the end of each line you can show as many cost columns for the activities as you need. The breakfast example shows just the capital cost of the consumable items and a revenue cost for labour and fuel. A Gantt chart like this can be used to keep track of progress for each activity and how the costs are running. You can move the time blocks around to report on actuals versus planned, and to re-schedule, and to create new plan updates. Costs columns can show plan and actuals and variances, and calculate whatever totals, averages, ratios, etc you need. Gantt Charts are the most flexible and useful of all project management tools, but remember they do not show the importance and inter-dependence of related parallel activities, and they will not show the necessity to complete one task before another can begin, as a critical path analysis will do, so you need both tools, especially at the planning stage.e) Project financial planning and reportingFor projects, involving more than petty cash you will need a spreadsheet to plan and report planned and actual expenditure. Use MSExcel or similar. If you do not know how to put together a basic financial plan, get some help from someone who knows. Make sure you bring a good friendly, flexible financial person into your team - it is a key function of project management, and if you cannot manage the financial processes your self, you need to be able to rely completely on whoever does it for you. The spreadsheet must enable you to plan, administer and report the detailed finances of your project. Create a cost line for main expenditure activity, and break this down into individual elements. Create a system for allocating incoming invoices to the correct activities (your bought-ledger people will not know unless you tell them), and showing when the costs hit the project account. Establish clear payment terms with all suppliers and stick to them. Projects develop problems when team members get dissatisfied; rest assured, non- or late-payment is a primary cause of dissatisfaction.Remember to set some budget aside for 'contingencies' - you will need it.f) Project contingency planningPlanning for and anticipating the unforeseen, or the possibility that things may not go as expected, is called 'contingency planning'. Contingency planning is vital in any task when results and outcomes cannot be absolutely guaranteed. Often a contingency budget needs to be planned, as there are usually costs associated. Contingency planning is about preparing fallback actions, and making sure that leeway for time, activity and resource exists to rectify or replace first-choice plans. A simple contingency plan for the fried breakfast would be to plan for the possibility of breaking the yolk of an egg, in which case spare resource (eggs) should be budgeted for and available if needed. Another might be to prepare some hash browns and mushrooms in the event that any of the diners are vegetarian. It may be difficult to anticipate precisely what contingency to plan for in complex long-term projects, in which case simply a contingency budget is provided, to be allocated later when and if required.3. Correspond the project plan to the project group.This serves two purposes: it informs people what is happening, and it obtains essential support, agreement and commitment. If your project is complex and involves a team, then you should involve the team in the planning process to maximize buy-in, ownership, and thereby accountability. Your project will also benefit from input and consultation from relevant people at an early stage.4. Consent and allot project actions.Your plan will have identified those responsible for each activity. Activities need to be very clearly described, including all relevant parameters, timescales, costs, and deliverables. When delegated tasks fail this is typically because they have not been explained clearly, agreed with the other person, or supported and checked while in progress. So publish the full plan to all in the team, but do not issue all the tasks unless the recipients are capable of their own forward planning. Long-term complex projects need to be planned in more detail and great care must be taken in delegating and supporting them. Do not delegate anything unless it makes sure for perfection.5. Control, encourage, notify, promote, and facilitate the project team.Manage the team and activities by meeting, communicating, supporting, and helping with decisions. Admire vociferously; charge quietly. One of the big challenges for a project manager is deciding how much freedom to give for each delegated activity. Tight parameters and lots of checking are necessary for inexperienced people who like clear instructions, but this approach is the kiss of death to experienced, entrepreneurial and creative people. They need a wider brief, more freedom, and less checking. Manage these people by the results they get - not how they get them. Look out for differences in personality and working styles in your team. They can get in the way of understandingand cooperation. Your role here is to enable and translate. Face to face meetings, when you can bring team members together, are generally the best way to avoid issues and relationships becoming personalized and emotional. Communicate progress and successes regularly to everyone. Give the people in your team the applause, particularly when someone high up expresses satisfaction - You must take the blame for anything that goes wrong - never dump on anyone in your team.6. Verify, assess, evaluate project development; regulate project procedure, and notify the project members and others.Check the progress of activities against the plan. Review performance regularly and at the stipulated review points, and confirm the validity and relevance of the remainder of the plan. Adjust the plan if necessary in light of performance, changing circumstances, and new information, but remain on track and within the original terms of reference. Be sure to use transparent, pre-agreed measurements when judging performance. Identify, agree and delegate new actions as appropriate. Inform team members and those in authority about developments, clearly, concisely and in writing. Plan team review meetings. Stick to the monitoring systems you established. Probe the apparent situations to get at the real facts. Examine causes and learn from mistakes. Identify reliable advisors and experts in the team and use them. Keep talking to people, and make yourself available to all.7. Finish project; evaluation and report on project performance; Admire and thanks to the project members.At the end of your successful project, hold a review with the team. Ensure you understand what happened and why. Replicate on any failures and mistakes positively, objectively, and without allocating personal blame. Reflect on successes gratefully and realistically. Write a review report, and make observations and recommendations about follow up issues and priorities - there will be plenty.As project manager, to be at the end of a project and to report that the project plan has been fully met, on time and on budget, is a significant achievement, whatever the project size and complexity. The mix of skills required is such that good project managers can manage anything.Conclusions:Businesses sometimes use formal systems development processes. These help assure that systems are developed successfully. A formal process is more effective in creating strong controls, and auditors should review this process to confirm that it is well designed and is followed in practice. A good formal systems development plan outlines: • A strategy to align development with the organization’s broader objectives•Standards for new systems•Project management policies for timing and budgeting•Procedures describing the processRegardless of the methodology used, the project development process will have the same above major stages: requirement for the project, Plan the project, project group, project actions, project team, evaluate project development, regulate project procedure and finish project; evaluation and report on project performance; Admire and thanks to the project members.References:1.Project Management Guidebook2.How to Manage Projects, Priorites and Deadlines3.Project Manager Today, January 2008.4.The Big Project, July 2008.<><><><><><><><><><><><><><><><>><><><><><><>><><><><><><><><> © Durgesh Burde. The author can be reached at durgesh19@ . The author is freelance writer and his area of research is project management and human development.。

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MCU-Based Aquaculture System V. B. De Leon, A. H. Ballado Jr., P. Dychitan Jr., R. GustiloAbstract—Developments in the field of control technology stretched the limits of its application in the field of aquaculture. Hence, this study was carried out to utilize microcontrollers to provide the necessary control of several variables or parameters i.e., pH, temperature and water level in an aquaculture system. The versatility of microcontroller programming allowed the manipulation of the range of parameter values, which could be altered depending on the needs of the system. Likewise, other features of the study included ease of monitoring and data logging. The construction of a simulation tank exhibiting different water quality conditions was carried out to capture dynamic aquacultural situations. Remote monitoring and data collection were an integral part of this study. However, the researcher welcomes further improvements in terms of additional parameters - oxygen level, salinity, phosphate level, and the like - necessary for optimum fish growth, and the use of modern advanced control algorithms to improve the system’s efficiency and speed.Index Terms -microcontroller, aquaculture system, remote terminal unit, data loggerI.I NTRODUCTIONIt is relatively fitting that tilapia can be called colloquially as “aquatic chicken” because of its high growth rate, adaptability to a wide range of environmental conditions, growth and reproduction even in captivity. Not quite surprisingly, this fish has become an excellent candidate for aquaculture, especially in tropical and subtropical environments. Raising tilapia as an inexpensive meat source can be very promising considering the health risks and high costs associated with the consumption of red meat.Tilapia culture is believed to have originated more than 4000 years ago, but very little information was available on their culture during those ancient times. Tilapia farming began from the Nile Valley and spread to central and western Africa.Manuscript reviewed February 28, 2011; revised June 29, 2011. This work was supported by the ERDT program of the Department of Science and Technology.V. B. de Leon finished his MS ECE in Mapúa Institute of Technology. He also holds a MS Math degree from Ateneo de Manila University. He finished his BS ECE from Rizal Technological University. He is currently pursuing his PhD in ECE in Mapúa Institute of Technology. (email: Voltaire.deleon@).A. H. Ballado Jr. received his BS ECE in 1995 from Mapúa Institute of Technology Manila, Philippines. He earned his MS in Electronics Engineering also from the same Institute, in 1999. Currently, he is a candidate for a PhD in Electronics Engineering at the De La Salle University, Philippines. Presently, he is a professor and the program chair of the Electronics Engineering program in Mapúa. (e-mail: ahballado@.ph).P. M. Dychitan Jr. finished his BS ECE in Don Bosco Technical College in 1993. He is at present the president of Dychitan Electronics Corporation. (e-mail: jun@).R. C. Gustilo earned his MS ECE from Ateneo. He obtained his BS ECE from the Technological Institute of the Philippines. He taught at various schools and universities like Mapúa and Adamson. He is currently a PhD candidate in ECE in De La Salle University (e-mail:reghie@).The first trials of tilapia aquaculture were recorded in Kenya in the 1920s, while artificial introductions of this species in many Asian and some Pacific Island countries started in the 1950s [1]. Since then, breeding of tilapia has been established in many tropical and subtropical regions, and even in areas beyond their native ranges, where they have been introduced for various purposes. As a result, considerable attention has been paid to tilapia aquaculture during the past three decades. Tilapia farming is expanding worldwide in both developed and developing countries because this group of fish can be cultured under very basic conditions. While it is ideal for rural subsistence farming, tilapia is amenable to more sophisticated, market-oriented culture programs, for these fish have high reproductive and growth rates, are relatively disease-free and hardy in nature [2]. Tilapia aquaculture is currently practiced in more than a hundred countries all around the globe yet alongside the popularity of culturing tilapia are important growth factors that need to be considered which include pH, temperature, and water level (depth); hence, the monitoring and control of these parameters through the utilization of control systems will be the goal of this research.Through the use and application of control systems, this study will monitor and control each factor based on set values of parameters affecting the growth of the fish. The resulting controlled environment after the application or implementation of process control mechanisms will be crucial in determining the success of growing excellent quality tilapia fit for high-demand human consumption. Generally, the objective of this research is to construct/ build a control system for aquaculture. Specifically, this research seeks to:create an algorithm incorporating the monitoring andcontrol of pH, temperature and water level of theaquatic environment;design a control system for monitoring and control ofthe three growth factors: pH, temperature, and waterlevel;provide means/ solutions for maintaining the ph,temperature, and depth of the water environment basedon specified set values; andutilize C language for the source code or program toimplement the algorithm.II.M ETHODOLOGYThe procedures in designing and building the control system in automating tilapia aquaculture will be discussed systematically in this section. The block diagram of the proposed system is shown in Fig.1.The process algorithm that will provide control for pH, temperature, and water level of aquarium water is presented in Fig. 2.Sensors being used as transducers will send appropriate signals to the microcontroller which will adjust the factor/s that need/s to be corrected. Altogether, these devices will give the control necessary to maintain set values of parameters for tilapia aquaculture.Fig. 1. Block diagram for the control system implementation for tilapiaaquaculture.Fig.2. Process algorithm. The simulation tank holding 15gallons of water will be equipped with temperature, pH, and water level sensors strategically placed inside the tank. It is provided with a drain valve that would flush out water in the event of water-quality correction. An aerator (with abuilt-in filter) installed in the system will distribute oxygen evenly in the water. The tank comes with two reservoirs, one containing alkaline water and tap water on the other, which will neutralize acidity or alkalinity beyond the specified range of values ideal for tilapia growth. Likewise, a reservoir for cold water for water temperature correction is also supplied.Pumps are attached within the tanks to hasten the flow of water/ solution from the reservoirs. Similarly, a pumpwas attached to the drain valve to ensure faster water exit.Data will be gathered every 15 minutes and can be monitored indefinitely. For this study, six hours of monitoring were observed for a given date. If water-correcting action is being done, this will be included within the data log. A visual display showing the status of parameters and sensoractions for periodical inspection was also supplied. Range of values of parameters can be interactively altered with this display using the microcomputer. The microcontroller comes with a data logger where one can monitor the status of the system.The following are the considerations and parameters involved in the operation of the MCU-based aquaculture system:At the heartof the system is an RCM 4300 RabbitCoreMicroController Unit which will be usedto provide control. It comes with a data logger andequipped with relays.ThepH sensor (8205 Digital pH Transmitter/ Burkert, Germany) will measure the acidityof aquarium water. Depending onthe detected water chemistry, it will send the appropriate signal to themicrocontroller which will in turn perform thenecessary control action with the opening or closingof water-composition-correcting valves throughrelays.The temperature sensor (8400 Screw-in TemperatureSensor, Burkert, Germany) will measure thetemperature of aquarium water. If water is too warmbased on a given set of values, it will send a signal tothe microcontroller which will in turn trigger theopening of the cold-water reservoir valve (mineralwater dispenser).Two float level switches/ sensors (top level/ bottomlevel sensors) will detect the depth of water in thetank. Both switches are closed when submerged inwater and opens when water level is below theswitch.Indicators (LEDs) in the relay board will indicatewhich valve is open or close to indicate correctingaction.Alkaline reservoir which contains limewater solution(hydrated calcium oxide) will provide the base toneutralize acidity (neutralization reaction).Tap water reservoir will supply water into the tank ascorrecting action if aquarium water gets too basic orif water level dips below the level sensors.Cold-water reservoir will provide the water forcooling action if aquarium water gets too warm.Solenoid valves (6013 Compact Solenoid Valve,Burkert, Germany) 1/8 ” diameter will open/ closeappropriately in the process of water chemistrycorrection and are connected to the drain, tap andalkaline solution reservoir.Water is circulated around the system with asubmersible pump.The simulation tank is a 15-gallon translucentaquarium for easy observation.For the initial conditions in the design of the aquaculturesystem, the parameters ideal for tilapia growth were used.These were the following:a)pH range of 6.5 – 8.0 [3]b)temperature of 30 °C or less [4]c)water level just above the top level sensor [5]From tilapia culture literature, it was noted that the fish willattain optimal growth if water quality is maintained with a pHof 6.5 to 8.0. Values that would exceed the range above orbelow and maintained for several days would be fatal to thefish. Likewise, temperature exceeding 30 °C for prolongedperiods will eventually result to fish kill. But temperaturesbelow it, even lower than 25 degrees will have little effect onthe fish.It could be noted from the algorithm that pH control takesprecedence over temperature control while water level isalways maintained for every corrective action. Since the setupis indoors, temperature is a secondary consideration forcontrol unlike pH level which could abruptly change thechemistry of the water resulting from the decay of feeds givento the fish and wastes coming from them in the form ofdissolved salts [6]. Temperature change could be a slowerprocess compared to pH change. Hence, if all parametersneed to be corrected, it would be pH that would be givenpriority as evidenced from the main program.The following status entries were used in the system todescribe certain conditions:High pH correction- a state where the pH ofaquarium water is greater than 8.0Low pH correction- a state where the pH of aquariumwater is below 6.5High Temperature correction- a state where thetemperature of aquarium water is more than 30 °CPassive - a state where corrections had already beenintroduced followed by a time of inactivityMonitoring- a state where the system is “waiting” forwater-quality deviations to occurA.High pH Correction AlgorithmThe system is pre-programmed to control the pH level from6.5 to 8.0. When the pH of aquarium water regardless of itstemperature exceeds a pH of 8.0 as sensed by the pHtransmitter, the microcontroller will send a signal to the relayswitch which will open the drain valve. Water will escapefrom the aquarium for a period of 60 seconds (preset timedelay). During this time, the top-level sensor would be opensince water would have escaped already. No corrective actionwill take place if this time delay has not yet elapsed. Oncethis time elapsed, the drain valve will close and the correctiveaction will take place. Since the water quality is basic/alkaline, it will open the tap water valve which would allowtap water from the tap water reservoir to flow to the aquarium.This process would continue until the top-level sensor closes.Once closed, the passive state will set in. This is the stagewhere no action takes place to give time for the system toadjust the correction done (settling time). Once the passivedelay has elapsed (system has been preset with a passive delayof 60 seconds), the pH of the water will be measured again. Ifit falls within the range, then temperature will now bemonitored with the water level maintained. Otherwise, the pHwill be corrected again and the process above will be repeated.Refer to Figure 3.Fig. 3. High pH correction.B.Low pH Correction AlgorithmWhen the pH of aquarium water regardless of itstemperature falls below a pH of 6.5 as sensed by the pHtransmitter, the microcontroller will send a signal to the relayswitch which will open the drain valve. Water will escapefrom the aquarium for a period of 60 seconds (preset timedelay). During this time, the top-level sensor would opensince water would have escaped already. No corrective actionwilltake place if this time delay has not yet elapsed. Oncethis time elapsed, the drain valve will close and the correctiveaction will take place. Since the water quality is acidic, it willopen the alkaline water valve which would allow alkalinewater from the alkaline water reservoir to flow to theaquarium. This process would continue until the top-levelsensor closes. Once closed, the passive state will set in. Thisis the stage where no action takes place to give time for the system to adjust the correction done (settling time). Once the passive delay has elapsed (system has been preset with a passive delay of 60 seconds), the pH of the water will be measured again. If it falls within the range, then temperature will now be monitored with the water level maintained. Otherwise, the pH will be corrected again and the process above will be repeated.C.High Temperature Correction AlgorithmWhen the temperature of aquarium water reaches more than 30 °C as sensed by the temperature transmitter, the microcontroller will send a signal to the relay switch which will open the drain valve. Water will escape from the aquarium for a period of 60 seconds (preset time delay). During this time, the top-level sensor would open since water would have escaped already. No corrective action will take place if this time delay has not yet elapsed. Once this time elapses, the drain valve will close and the corrective action will take place. Since the water quality is warm, it will open the cold-water valve which would allow cold water from the cold-water reservoir to flow to the aquarium. This process would continue until the top-level sensor closes. Once closed, the passive state will set in. This is the stage where no action takes place to give time for the system to adjust the correction done (settling time). Once the passive delay has elapsed (system has been preset with a passive delay of 60 seconds), the temperature of the water will be measured again. If it still falls above 30°C, then the temperature will be corrected again and the process above will be repeated.D.Automated pH Correction System DisplayThe aquaculture system is provided with a display operating in real-time to provide an update of what is happening to the system as exhibited in Fig. 4.Fig. 4. Sample screen display.The Status field will tell us the condition of the system whether it is in high pH correction, low pH correction, high temperature correction, passive status, or monitoring status.The pH Level field will indicate the alkalinity or acidity of the aquarium water. The Temperature field will show us the present temperature of aquarium water. The Top Level Sensor field will tell us if water level in the aquarium is above or below it.The Drain Valve field will indicate if the drain valve is close or open. An open drain valve lets water out of the aquarium.The Lime Water field will show us if alkaline water valve is open or close. An open limewater lets alkaline water out of the alkaline water reservoir to neutralize acidity.The Tap Water field will tell us if the tap water valve is open or close. An open tap water means that tap water is introduced into the system to correct high pH or low water level.The Cold Tap Water field indicates if the cold-water valve is open or close. An open cold tap water introduces cold water into the system to correct high water temperature.The Date/ Time field shows the present time and date.E.Configuration DisplayAn aquaculturist can alter the pH range and temperature setting of the system as depicted in Fig. 5. Likewise, the time delay and passive delay could be changed. The time delay for the system is defined as the time taken for the drain valve to release water from the aquarium.Fig.5. Configuration display screen.Passive delay for the system is defined as the time it takes for the system to remain in a state where no corrective action takes place. This is also the time aquarium water settles down after being corrected.The pH Lower Limit and pH Upper Limit field could be changed to accommodate a range of pH values appropriate for the type of fish in to be cultured.The Temp Upper Limit can be altered to allow a new temperature set point to be maintained.The Time and Passive delay could likewise be reset.III.R ESULTSSimulating different water conditions were done through the use of concentrated alkaline solution, muriatic acid (hydrochloric acid), and water heater. For this simulation lasting six hours, the results were noted using the output of thedata logger.The entries in the data log are in the following order: date, time of monitoring, status, pH level, temperature, top-level sensor status, and bottom- level sensor status.A.Simulation and Data LoggingData logging started on the first of December, 2010 at 3: 17 pm (System, Start up) and ended at 9:15 pm. For presentation purposes, time was expressed in minutes and pH values were the same numerical figures recorded in the data logger. The range of pH values maintained by the control system is from 6.5 to 8.0.As presented in the data log, there were three instances when the graph was above the eighth pH mark (High pH Correction). The system responded to correct the high pH during the first simulated pH change. The pH was already correct at 7.96 recorded at 3:50 pm. We could conclude that it took around 27 minutes for this correction to take place. The second “shock” happened at 4: 42 pm. The pH of aquarium water was already correct at 4: 58 after more than 16 minutes. The last correction took place at 5:32 pm. The system corrected the pH after more than 15 minutes. The system stabilized at 5:52 pm.The temperature to be maintained by the control system is 30 °C or less.There were three instances where the graph was above the 30 °C mark indicative of a high temperature status of aquarium water. The system responded to correct the high temperature during the first simulated temperature change. The temperature was already correct at 29.6 °C recorded at 3:57 pm. We could conclude that it took around 15 minutes for this correction to take place. The second “shock” happened at 4:33 pm. The temperature of aquarium water was already correct at 4:42 after 9 minutes. The last recorded high temperature situation took place at 5:02 pm. The temperature stabilized at 5:09 pm.When water level goes above a sensor (top or bottom), the status of the sensor would read “above”. The opposite is true when water level is below the sensor, thus, the status of the sensor woul d read “below”. A s monitored from 3:17 pm until 9:15 pm, the status of the two sensors was “below”. This will not come as a surprise, since water level is always maintained for every change in pH or temperature that will happen. One may also refer to the flowchart (see fig. 3) and note that water level is always checked or monitored every step of the way. B.SMS MonitoringData logging apart from being directly done with a laptop computer via Wi-Fi can also be accomplished remotely through Short Message Service. The procedure would be carried by typing “1234 status” on a mobile phone and sending this message to 09279221966. Then, an SMS text message will be received by the sender displaying the status, date, time, pH level, temperature, water level condition (above or below), drain valve condition (open or close), alkaline valve condition (open or close), tap water valve condition (open or close) and cold water valve condition (open or close).IV.C ONCLUSIONAn MCU-based aquaculture system proved that monitoring and control of different parameters or factors for optimum fish growth can be done easily and remotely. Unlike the earlier means of monitoring and control that involved actual visit to the site, these things could now be done conveniently through a mobile phone, or a laptop computer connected to the Internet.Based on the results of controlling several variables altogether, we could conclude that one factor is related to another when simulations were done in the system, that is, temperature, pH, and water volume are all functions of each other. Consequently, a change in a variable will favor a corresponding change in the other. Also, the monitoring of pH based on the sampled monitoring period showed that pH correction is relatively faster than temperature correction. However, in the course of simulation, an outlier was observed. Temperature correction alone took a while before settling in the desired value. See Figure 6. This may be attributed to the fact that water volume is a function of specific heat. The greater volume of water, the greater time will be spent to heat it up. The pH of water could be easily changed depending on the concentration of the acid or base to be used. The result of the study showed that the pH of aquarium water responded fast with the addition of either acid or base. Therefore, microcontrollers are versatile and sound devices that produce the desired output with considerable accuracy and efficiency.R EFERENCES[1]S. Nandlal, Tilapia Hatchery Operation, Tilapia fish farming in PacificIsland Countries, vol. I, 2004.[2] A. El-Sayed, Tilapia Culture, 2006.[3]P. Fowler, D. Baird, R. Bucklin, S. Yerlan, C. Watson, and F.Chapman,“Microcontrollers in recirculating aquaculture,” EES-326, University of Florida, 1994.[4]Balarin, J.D. and Haller, R.D., Recent Advances in Aquaculture, 1982.[5]El-Sayed, A.-F.M., Mansour, C.R. and Ezzat, A. Aquaculture, pp. 619–632.[6]Wangead, et al (1988) Effects of acid water on survival and growth rateof Nile tilapia (Oreochromis niloticus). In: Pullin, R.S.V., Bhukaswan, T., Tonguthai, K. and Maclean, J.L. (eds) Proceedings of the Second International Symposium on Tilapia in Aquaculture.Fig.6. pH vs. time chart。

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