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毕业论文(设计)外文文献翻译及原文

毕业论文(设计)外文文献翻译及原文

金融体制、融资约束与投资——来自OECD的实证分析R.SemenovDepartment of Economics,University of Nijmegen,Nijmegen(荷兰内梅亨大学,经济学院)这篇论文考查了OECD的11个国家中现金流量对企业投资的影响.我们发现不同国家之间投资对企业内部可获取资金的敏感性具有显著差异,并且银企之间具有明显的紧密关系的国家的敏感性比银企之间具有公平关系的国家的低.同时,我们发现融资约束与整体金融发展指标不存在关系.我们的结论与资本市场信息和激励问题对企业投资具有重要作用这种观点一致,并且紧密的银企关系会减少这些问题从而增加企业获取外部融资的渠道。

一、引言各个国家的企业在显著不同的金融体制下运行。

金融发展水平的差别(例如,相对GDP的信用额度和相对GDP的相应股票市场的资本化程度),在所有者和管理者关系、企业和债权人的模式中,企业控制的市场活动水平可以很好地被记录.在完美资本市场,对于具有正的净现值投资机会的企业将一直获得资金。

然而,经济理论表明市场摩擦,诸如信息不对称和激励问题会使获得外部资本更加昂贵,并且具有盈利投资机会的企业不一定能够获取所需资本.这表明融资要素,例如内部产生资金数量、新债务和权益的可得性,共同决定了企业的投资决策.现今已经有大量考查外部资金可得性对投资决策的影响的实证资料(可参考,例如Fazzari(1998)、 Hoshi(1991)、 Chapman(1996)、Samuel(1998)).大多数研究结果表明金融变量例如现金流量有助于解释企业的投资水平。

这项研究结果解释表明企业投资受限于外部资金的可得性。

很多模型强调运行正常的金融中介和金融市场有助于改善信息不对称和交易成本,减缓不对称问题,从而促使储蓄资金投着长期和高回报的项目,并且提高资源的有效配置(参看Levine(1997)的评论文章)。

因而我们预期用于更加发达的金融体制的国家的企业将更容易获得外部融资.几位学者已经指出建立企业和金融中介机构可进一步缓解金融市场摩擦。

文献翻译 译文+原文

文献翻译 译文+原文

09届本科毕业设计(论文)外文文献翻译学 院: 物理与电子工程学院专 业: 光电信息工程姓 名: 徐 驰学 号: Y05209222 外文出处: Surface & Coatings Technology214(2013)131-137附 件: 1.外文资料翻译译文;2.外文原文。

(用外文写)附件1:外文资料翻译译文气体温度通过PECVD沉积对Si:H薄膜的结构和光电性能的影响摘要气体温度的影响(TG)在等离子体增强化学气相沉积法(PECVD)生长的薄膜的结构和光电特性:H薄膜已使用多种表征技术研究。

气体的温度被确定为制备工艺的优化、结构和光电薄膜的性能改进的一个重要参数。

薄膜的结构性能进行了研究使用原子力显微镜(AFM),傅立叶变换红外光谱(FTIR),拉曼光谱,和电子自旋共振(ESR)。

此外,光谱椭偏仪(SE),在紫外线–可见光区域的光传输的测量和电气测量被用来研究的薄膜的光学和电学性能。

它被发现在Tg的变化可以修改的表面粗糙度,非晶网络秩序,氢键模式和薄膜的密度,并最终提高光学和电学性能。

1.介绍等离子体增强化学气相沉积法(PECVD)是氢化非晶硅薄膜制备一种技术,具有广泛的实际应用的重要材料。

它是用于太阳能电池生产,在夜视系统红外探测器,和薄膜晶体管的平板显示装置。

所有这些应用都是基于其良好的电气和光学特性以及与半导体技术兼容。

然而,根据a-Si的性质,PECVD制备H薄膜需要敏感的沉积条件,如衬底温度,功率密度,气体流量和压力。

许多努力已经花在制备高品质的薄膜具有较低的缺陷密度和较高的结构稳定性的H薄膜。

众所周知,衬底温度的强烈影响的自由基扩散的生长表面上,从而导致这些自由基更容易定位在最佳生长区。

因此,衬底温度一直是研究最多的沉积参数。

至于温度参数在PECVD工艺而言,除了衬底温度,气体温度(Tg)美联储在PECVD反应室在辉光放电是定制的a-Si的性能参数:H薄膜的新工艺。

通信类英文文献及翻译

通信类英文文献及翻译

附录一、英文原文:Detecting Anomaly Traffic using Flow Data in the realVoIP networkI. INTRODUCTIONRecently, many SIP[3]/RTP[4]-based VoIP applications and services have appeared and their penetration ratio is gradually increasing due to the free or cheap call charge and the easy subscription method. Thus, some of the subscribers to the PSTN service tend to change their home telephone services to VoIP products. For example, companies in Korea such as LG Dacom, Samsung Net- works, and KT have begun to deploy SIP/RTP-based VoIP services. It is reported that more than five million users have subscribed the commercial VoIP services and 50% of all the users are joined in 2009 in Korea [1]. According to IDC, it is expected that the number of VoIP users in US will increase to 27 millions in 2009 [2]. Hence, as the VoIP service becomes popular, it is not surprising that a lot of VoIP anomaly traffic has been already known [5]. So, Most commercial service such as VoIP services should provide essential security functions regarding privacy, authentication, integrity and non-repudiation for preventing malicious traffic. Particu- larly, most of current SIP/RTP-based VoIP services supply the minimal security function related with authentication. Though secure transport-layer protocols such as Transport Layer Security (TLS) [6] or Secure RTP (SRTP) [7] have been standardized, they have not been fully implemented anddeployed in current VoIP applications because of the overheads of implementation and performance. Thus, un-encrypted VoIP packets could be easily sniffed and forged, especially in wireless LANs. In spite of authentication,the authentication keys such as MD5 in the SIP header could be maliciously exploited, because SIP is a text-based protocol and unencrypted SIP packets are easily decoded. Therefore, VoIP services are very vulnerable to attacks exploiting SIP and RTP. We aim at proposing a VoIP anomaly traffic detection method using the flow-based traffic measurement archi-tecture. We consider three representative VoIP anomalies called CANCEL, BYE Denial of Service (DoS) and RTP flooding attacks in this paper, because we found that malicious users in wireless LAN could easily perform these attacks in the real VoIP network. For monitoring VoIP packets, we employ the IETF IP Flow Information eXport (IPFIX) [9] standard that is based on NetFlow v9. This traffic measurement method provides a flexible and extensible template structure for various protocols, which is useful for observing SIP/RTP flows [10]. In order to capture and export VoIP packets into IPFIX flows, we define two additional IPFIX templates for SIP and RTP flows. Furthermore, we add four IPFIX fields to observe packets which are necessary to detect VoIP source spoofing attacks in WLANs.II. RELATED WORK[8] proposed a flooding detection method by the Hellinger Distance (HD) concept. In [8], they have pre- sented INVITE, SYN and RTP flooding detection meth-ods. The HD is the difference value between a training data set and a testing data set. The training data set collected traffic over n sampling period of duration Δ testing data set collected traffic next the training data set in the same period. If the HD is close to ‘1’, this testing data set is regarded as anomaly traffic. For using this method, they assumed that initial training data set didnot have any anomaly traffic. Since this method was based on packet counts, it might not easily extended to detect other anomaly traffic except flooding. On the other hand, [11] has proposed a VoIP anomaly traffic detection method using Extended Finite State Machine (EFSM). [11] has suggested INVITE flooding, BYE DoS anomaly traffic and media spamming detection methods. However, the state machine required more memory because it had to maintain each flow. [13] has presented NetFlow-based VoIP anomaly detection methods for INVITE, REGIS-TER, RTP flooding, and REGISTER/INVITE scan. How-ever, the VoIP DoS attacks considered in this paper were not considered. In [14], an IDS approach to detect SIP anomalies was developed, but only simulation results are presented. For monitoring VoIP traffic, SIPFIX [10] has been proposed as an IPFIX extension. The key ideas of the SIPFIX are application-layer inspection and SDP analysis for carrying media session information. Yet, this paper presents only the possibility of applying SIPFIX to DoS anomaly traffic detection and prevention. We described the preliminary idea of detecting VoIP anomaly traffic in [15]. This paper elaborates BYE DoS anomaly traffic and RTP flooding anomaly traffic detec-tion method based on IPFIX. Based on [15], we have considered SIP and RTP anomaly traffic generated in wireless LAN. In this case, it is possible to generate the similiar anomaly traffic with normal VoIP traffic, because attackers can easily extract normal user information from unencrypted VoIP packets. In this paper, we have extended the idea with additional SIP detection methods using information of wireless LAN packets. Furthermore, we have shown the real experiment results at the commercial VoIP network.III. THE VOIP ANOMALY TRAFFIC DETECTION METHOD A. CANCEL DoS Anomaly Traffic DetectionAs the SIP INVITE message is not usually encrypted, attackers could extract fields necessary to reproduce the forged SIP CANCEL message by sniffing SIP INVITE packets, especially in wireless LANs. Thus, we cannot tell the difference between the normal SIP CANCEL message and the replicated one, because the faked CANCEL packet includes the normal fields inferred from the SIP INVITE message. The attacker will perform the SIP CANCEL DoS attack at the same wireless LAN, because the purpose of the SIP CANCEL attack is to prevent the normal call estab-lishment when a victim is waiting for calls. Therefore, as soon as the attacker catches a call invitation message for a victim, it will send a SIP CANCEL message, which makes the call establishment failed. We have generated faked SIP CANCEL message using sniffed a SIP INVITE in SIP header of this CANCEL message is the same as normal SIP CANCEL message, because the attacker can obtain the SIP header field from unencrypted normal SIP message in wireless LAN environment. Therefore it is impossible to detect the CANCEL DoS anomaly traffic using SIP headers, we use the different values of the wireless LAN frame. That is, the sequence number in the frame will tell the difference between a victim host and an attacker. We look into source MAC address and sequence number in the MAC frame including a SIP CANCEL message as shown in Algorithm 1. We compare the source MAC address of SIP CANCEL packets with that of the previously saved SIP INVITE flow. If the source MAC address of a SIP CANCEL flow is changed, it will be highly probable that the CANCEL packet is generated by a unknown user. However, the source MAC address could be spoofed. Regarding source spoofing detection, we employ the method in [12] that uses sequence numbers of frames. We calculate the gap between n-th and (n-1)-th frames. As the sequence number field in a MAC header uses 12 bits, it varies from 0 to 4095. When we find that the sequence number gap between a single SIP flow is greater than the threshold value of N that willbe set from the experiments, we determine that the SIP host address as been spoofed for the anomaly traffic.B. BYE DoS Anomaly Traffic DetectionIn commercial VoIP applications, SIP BYE messages use the same authentication field is included in the SIP IN-VITE message for security and accounting purposes. How-ever, attackers can reproduce BYE DoS packets through sniffing normal SIP INVITE packets in wireless faked SIP BYE message is same with the normal SIP BYE. Therefore, it is difficult to detect the BYE DoS anomaly traffic using only SIP header sniffing SIP INVITE message, the attacker at the same or different subnets could terminate the normal in- progress call, because it could succeed in generating a BYE message to the SIP proxy server. In the SIP BYE attack, it is difficult to distinguish from the normal call termination procedure. That is, we apply the timestamp of RTP traffic for detecting the SIP BYE attack. Generally, after normal call termination, the bi-directional RTP flow is terminated in a bref space of time. However, if the call termination procedure is anomaly, we can observe that a directional RTP media flow is still ongoing, whereas an attacked directional RTP flow is broken. Therefore, in order to detect the SIP BYE attack, we decide that we watch a directional RTP flow for a long time threshold of N sec after SIP BYE message. The threshold of N is also set from the 2 explains the procedure to detect BYE DoS anomal traffic using captured timestamp of the RTP packet. We maintain SIP session information between clients with INVITE and OK messages including the same Call-ID and 4-tuple (source/destination IP Address and port number) of the BYE packet. We set a time threshold value by adding Nsec to the timestamp value of the BYE message. The reason why we use the captured timestamp is that a few RTP packets are observed under second. If RTP traffic is observed after the time threshold, this willbe considered as a BYE DoS attack, because the VoIP session will be terminated with normal BYE messages. C. RTP Anomaly Traffic Detection Algorithm 3 describes an RTP flooding detection method that uses SSRC and sequence numbers of the RTP header. During a single RTP session, typically, the same SSRC value is maintained. If SSRC is changed, it is highly probable that anomaly has occurred. In addition, if there is a big sequence number gap between RTP packets, we determine that anomaly RTP traffic has happened. As inspecting every sequence number for a packet is difficult, we calculate the sequence number gap using the first, last, maximum and minimum sequence numbers. In the RTP header, the sequence number field uses 16 bits from 0 to 65535. When we observe a wide sequence number gap in our algorithm, we consider it as an RTP flooding attack.IV. PERFORMANCE EVALUATIONA. Experiment EnvironmentIn order to detect VoIP anomaly traffic, we established an experimental environment as figure 1. In this envi-ronment, we employed two VoIP phones with wireless LANs, one attacker, a wireless access router and an IPFIX flow collector. For the realistic performance evaluation, we directly used one of the working VoIP networks deployed in Korea where an 11-digit telephone number (070-XXXX-XXXX) has been assigned to a SIP wireless SIP phones supporting , we could make calls to/from the PSTN or cellular phones. In the wireless access router, we used two wireless LAN cards- one is to support the AP service, and the other is to monitor packets. Moreover, in order to observe VoIP packets in the wireless access router, we modified nProbe [16], that is an open IPFIX flow generator, to create and export IPFIX flows related with SIP, RTP, and information. As the IPFIX collector, we have modified libipfix so that it could provide the IPFIX flow decoding function for SIP, RTP, and templates. We used MySQL for the flow DB.B. Experimental ResultsIn order to evaluate our proposed algorithms, we gen-erated 1,946 VoIP calls with two commercial SIP phones and a VoIP anomaly traffic generator. Table I showsour experimental results with precision, recall, and F-score that is the harmonic mean of precision and recall. In CANCEL DoS anomaly traffic detection, our algorithm represented a few false negative cases, which was related with the gap threshold of the sequence number in MAC header. The average of the F-score value for detecting the SIP CANCEL anomaly is %.For BYE anomaly tests, we generated 755 BYE mes-sages including 118 BYE DoS anomalies in the exper-iment. The proposed BYE DoS anomaly traffic detec-tion algorithm found 112 anomalies with the F-score of %. If an RTP flow is terminated before the threshold, we regard the anomaly flow as a normal one. In this algorithm, we extract RTP session information from INVITE and OK or session description messages using the same Call-ID of BYE message. It is possible not to capture those packet, resulting in a few false-negative cases. The RTP flooding anomaly traffic detection experiment for 810 RTP sessions resulted in the F score of 98%.The reason of false-positive cases was related with the sequence number in RTP header. If the sequence number of anomaly traffic is overlapped with the range of the normal traffic, our algorithm will consider it as normal traffic.V. CONCLUSIONSWe have proposed a flow-based anomaly traffic detec-tion method against SIP and RTP-based anomaly traffic in this paper. We presented VoIP anomaly traffic detection methods with flow data on the wireless access router. We used the IETF IPFIX standard to monitor SIP/RTP flows passing through wireless access routers, because its template architecture is easily extensible to several protocols. For this purpose, we defined two new IPFIX templates for SIP and RTP traffic and four new IPFIX fields for traffic. Using these IPFIX flow templates,we proposed CANCEL/BYE DoS and RTP flooding traffic detection algorithms. From experimental results on the working VoIP network in Korea, we showed that our method is able to detect three representative VoIP attacks on SIP phones. In CANCEL/BYE DoS anomaly trafficdetection method, we employed threshold values about time and sequence number gap for classfication of normal and abnormal VoIP packets. This paper has not been mentioned the test result about suitable threshold values. For the future work, we will show the experimental result about evaluation of the threshold values for our detection method.二、英文翻译:交通流数据检测异常在真实的世界中使用的VoIP网络一 .介绍最近,许多SIP[3],[4]基于服务器的VoIP应用和服务出现了,并逐渐增加他们的穿透比及由于自由和廉价的通话费且极易订阅的方法。

外文文献翻译译稿

外文文献翻译译稿

外文文献翻译译稿1可用性和期望值来自Willliam S.Green, Patrick W.Jordan.产品的愉悦:超越可用性根据人机工程学会(HFES)的观点,人机工程学着眼于“发现和共享可用于各种系统和设备设计的、关于人的特点的知识”。

人们通常只是把它作为生物力学和人体测量所关注的内容,实际上它是从更广泛的意义上的一种对人(产品用户)的全面和综合的理解。

HFES从二战中有军方从事的系统分析中发展而来。

其中的三种主要研究的是人体测量、复杂信息的解释和管理,以及在部队和装备调配中应用的系统分析。

系统分析在尺度和复杂性方面跨度很大,大的系统分析有类似于诺曼底登陆准备的大型系统规划,小到去理解如何从合理性和规模的角度才最佳的布置和装备人员。

诺曼底登陆是20世纪最复杂的事件之一。

他要求建立一个在战斗开始之前还不确定的庞大的人员和物资的合理分配系统。

在更小的规模上,装备和军事人物的布置意味着如何去组织、训练和安排战士,最大限度的发挥他们的长处。

士兵必须迅速地接受训练,并且能够有效地使用和维护在二战中发展起来的一系列技术装备。

其中,对于飞行员、潜艇人员和坦克驾驶员有神采的限制。

复杂的新装备的开发要求找到最好的税收、密码便医院、破译人员、雷达和声纳操作员、轰炸机驾驶员和机组人员。

在战后,随着公司及其产品在尺度、领域和复杂性方面的增长,很多系统分析人员在商用领域找到了发展机会。

尽管是战后的发展才导致了1957年人机工程协会(HFES)的建立,但人机研究的起源可以追溯到大批量生产方式的成型阶段,是当时提高生产效率的要求。

随着工作方式从手工生产和农业生产中的转移,新的工厂工作的概念逐步发展起来。

福特的流水生产线和泰勒的效率理论开始对生产的规划和教育产生影响。

即使在家庭生活中,妇女们也开始接受了现代家庭管理理论,并运用这些理论来组织和规划家庭。

在20世纪末,一种涵盖面更广的人机工程正在发展之中。

新的人机工程学是为了适应已经被广泛意识到的对用户行为模式更深入的需求而诞生的,它开始应用定型研究方法,并探索人的情感和认知因素。

外文文献翻译译稿和原文【范本模板】

外文文献翻译译稿和原文【范本模板】

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.随着离散时间的每一个增加,这个线性算子就会作用在当前状态上,产生一个新的状态,并也会带入一些噪声,同时系统的一些已知的控制器的控制信息也会被加入。

文献通考总序原文翻译

文献通考总序原文翻译

文献通考总序原文翻译The total preface of "Wenxian Tongkao" translation:"enxian Tongkao" is a monumental work written by Chinese scholar Gu Yanwu during the late Ming Dynasty. It is a comprehensive study of Chinese history and literature, and is recognized as one of the most important works in Chinese historiography.In the preface of "Wenxian Tongkao" Gu Yanwu discusses the importance of studying history and the necessity of writing a comprehensive record of Chinese literature and history. He believes that by studying the past, one can gain a deeper understanding of the present and make better decisions for the future. Gu Yanwu also emphasizes the need for accuracy and objectivity in historical research, and criticizes the tendency of some scholars to manipulate historical records for personal or political gain.Furthermore, Gu Yanwu emphasizes the importance of studying literature as a means of understanding culture and society. He argues that literature reflects the beliefs, values, and aspirations of a society, and provides valuable insights into human nature and the human condition. Gu Yanwu also emphasizes the need for scholars to approach literature withan open and critical mind, and to consider multiple perspectives when analyzing literary works.Overall, the preface of "Wenxian Tongkao" highlights the importance of studying history and literature, and provides a framework for conducting comprehensive and objective research in these fields. Gu Yanwu"s insights and ideas continue to be influential in the field of Chinese studies, and his work serves as a valuable resource for scholars and researchers interested in Chinese history and literature.。

英文文献原文及对应翻译

英文文献原文及对应翻译

Adsorption char acter istics of copper , lead, zinc and cadmium ions by tourmaline(环境科学学报英文版) 电气石对铜、铅、锌、镉离子的吸附特性JIANG Kan1,*, SUN Tie-heng1,2 , SUN Li-na2, LI Hai-bo2(1. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. jiangkan522@; 2. Key Laboratory of Environmental Engineering of Shenyang University, Shenyang 110041, China)摘要:本文研究了电气石对Cu2+、Pb2+、Zn2+和Cd2+的吸附特性,建立了吸附平衡方程。

研究四种金属离子的吸附等温线以及朗缪尔方程。

结果表明电气石能有效地去除水溶液中的重金属且具有选择性:Pb2+> Cu2+> Cd2+> Zn2+。

电气石对金属离子吸附量随着介质中金属离子的初始浓度的增加而增加。

电气石也可以增加金属溶液的pH值;发现电气石对Cu2+、Pb2+、Zn2+和Cd2+的最大吸附量为78.86、154.08、67.25和66.67mg/g;温度在25-55℃对电气石的吸附量影响很小。

此外研究了Cu2+、Pb2+、Zn2+和Cd2+的竞争吸附。

同时观察到电气石对单一金属离子的吸附能力为Pb>Cu>Zn>Cd,在两种金属系统中抑制支配地位是Pb>Cu,Pb>Zn,Pb>Cd,Cu>Zn,Cu>Cd,和Cd>Zn。

关键字:吸附;重金属含量;朗缪尔等温线;电气石介绍重金属是来自不同行业排出的废水,如电镀,金属表面处理,纺织,蓄电池,矿山,陶瓷,玻璃。

论文外文文献翻译

论文外文文献翻译

论文外文文献翻译以下是一篇700字左右的论文外文文献翻译:原文题目:The Role of Artificial Intelligence in Medical Diagnostics: A Review原文摘要:In recent years, there has been a growing interest in the use of artificial intelligence (AI) in the field of medical diagnostics. AI has the potential to improve the accuracy and efficiency of medical diagnoses, and can assist clinicians in making treatment decisions. This review aims to examine the current state of AI in medical diagnostics, and discuss its advantages and limitations. Several AI techniques, including machine learning, deep learning, and natural language processing, are discussed. The review also examines the ethical and legal considerations associated with the use of AI in medical diagnostics. Overall, AI has shown great promise in improving medical diagnostics, but further research is needed to fully understand its potential benefits and limitations.AI在医学诊断中发挥的作用:一项综述近年来,人工智能(AI)在医学诊断领域的应用引起了越来越多的关注。

外文参考文献(带中文翻译)

外文参考文献(带中文翻译)

外文资料原文涂敏之会计学 8051208076Title:Future of SME finance(c)Background – the environment for SME finance has changedFuture economic recovery will depend on the possibility of Crafts, Trades and SMEs to exploit their potential for growth and employment creation.SMEs make a major contribution to growth and employment in the EU and are at the heart of the Lisbon Strategy, whose main objective is to turn Europe into the most competitive and dynamic knowledge-based economy in the world. However, the ability of SMEs to grow depends highly on their potential to invest in restructuring, innovation and qualification. All of these investments need capital and therefore access to finance.Against this background the consistently repeated complaint of SMEs about their problems regarding access to finance is a highly relevant constraint that endangers the economic recovery of Europe.Changes in the finance sector influence the behavior of credit institutes towards Crafts, Trades and SMEs. Recent and ongoing developments in the banking sector add to the concerns of SMEs and will further endanger their access to finance. The main changes in the banking sector which influence SME finance are:•Globalization and internationalization have increased the competition and the profit orientation in the sector;•worsening of the economic situations in some institutes (burst of the ITC bubble, insolvencies) strengthen the focus on profitability further;•Mergers and restructuring created larger structures and many local branches, which had direct and personalized contacts with small enterprises, were closed;•up-coming implementation of new capital adequacy rules (Basel II) will also change SME business of the credit sector and will increase its administrative costs;•Stricter interpretation of State-Aide Rules by the European Commission eliminates the support of banks by public guarantees; many of the effected banks are very active in SME finance.All these changes result in a higher sensitivity for risks and profits in the financesector.The changes in the finance sector affect the accessibility of SMEs to finance.Higher risk awareness in the credit sector, a stronger focus on profitability and the ongoing restructuring in the finance sector change the framework for SME finance and influence the accessibility of SMEs to finance. The most important changes are: •In order to make the higher risk awareness operational, the credit sector introduces new rating systems and instruments for credit scoring;•Risk assessment of SMEs by banks will force the enterprises to present more and better quality information on their businesses;•Banks will try to pass through their additional costs for implementing and running the new capital regulations (Basel II) to their business clients;•due to the increase of competition on interest rates, the bank sector demands more and higher fees for its services (administration of accounts, payments systems, etc.), which are not only additional costs for SMEs but also limit their liquidity;•Small enterprises will lose their personal relationship with decision-makers in local branches –the credit application process will become more formal and anonymous and will probably lose longer;•the credit sector will lose more and more i ts “public function” to provide access to finance for a wide range of economic actors, which it has in a number of countries, in order to support and facilitate economic growth; the profitability of lending becomes the main focus of private credit institutions.All of these developments will make access to finance for SMEs even more difficult and / or will increase the cost of external finance. Business start-ups and SMEs, which want to enter new markets, may especially suffer from shortages regarding finance. A European Code of Conduct between Banks and SMEs would have allowed at least more transparency in the relations between Banks and SMEs and UEAPME regrets that the bank sector was not able to agree on such a commitment.Towards an encompassing policy approach to improve the access of Crafts, Trades and SMEs to financeAll analyses show that credits and loans will stay the main source of finance for the SME sector in Europe. Access to finance was always a main concern for SMEs, but the recent developments in the finance sector worsen the situation even more.Shortage of finance is already a relevant factor, which hinders economic recovery in Europe. Many SMEs are not able to finance their needs for investment.Therefore, UEAPME expects the new European Commission and the new European Parliament to strengthen their efforts to improve the framework conditions for SME finance. Europe’s Crafts, Trades and SMEs ask for an encompassing policy approach, which includes not only the conditions for SMEs’ access to l ending, but will also strengthen their capacity for internal finance and their access to external risk capital.From UEAPME’s point of view such an encompassing approach should be based on three guiding principles:•Risk-sharing between private investors, financial institutes, SMEs and public sector;•Increase of transparency of SMEs towards their external investors and lenders;•improving the regulatory environment for SME finance.Based on these principles and against the background of the changing environment for SME finance, UEAPME proposes policy measures in the following areas:1. New Capital Requirement Directive: SME friendly implementation of Basel IIDue to intensive lobbying activities, UEAPME, together with other Business Associations in Europe, has achieved some improvements in favour of SMEs regarding the new Basel Agreement on regulatory capital (Basel II). The final agreement from the Basel Committee contains a much more realistic approach toward the real risk situation of SME lending for the finance market and will allow the necessary room for adaptations, which respect the different regional traditions and institutional structures.However, the new regulatory system will influence the relations between Banks and SMEs and it will depend very much on the way it will be implemented into European law, whether Basel II becomes burdensome for SMEs and if it will reduce access to finance for them.The new Capital Accord form the Basel Committee gives the financial market authorities and herewith the European Institutions, a lot of flexibility. In about 70 areas they have room to adapt the Accord to their specific needs when implementing itinto EU law. Some of them will have important effects on the costs and the accessibility of finance for SMEs.UEAPME expects therefore from the new European Commission and the new European Parliament:•The implementation of the new Capital Requirement Directive will be costly for the Finance Sector (up to 30 Billion Euro till 2006) and its clients will have to pay for it. Therefore, the implementation – especially for smaller banks, which are often very active in SME finance –has to be carried out with as little administrative burdensome as possible (reporting obligations, statistics, etc.).•The European Regulators must recognize traditional instruments for collaterals (guarantees, etc.) as far as possible.•The European Commission and later the Member States should take over the recommendations from the European Parliament with regard to granularity, access to retail portfolio, maturity, partial use, adaptation of thresholds, etc., which will ease the burden on SME finance.2. SMEs need transparent rating proceduresDue to higher risk awareness of the finance sector and the needs of Basel II, many SMEs will be confronted for the first time with internal rating procedures or credit scoring systems by their banks. The bank will require more and better quality information from their clients and will assess them in a new way. Both up-coming developments are already causing increasing uncertainty amongst SMEs.In order to reduce this uncertainty and to allow SMEs to understand the principles of the new risk assessment, UEAPME demands transparent rating procedures –rating procedures may not become a “Black Box” for SMEs: •The bank should communicate the relevant criteria affecting the rating of SMEs.•The bank should inform SMEs about its assessment in order to allow SMEs to improve.The negotiations on a European Code of Conduct between Banks and SMEs , which would have included a self-commitment for transparent rating procedures by Banks, failed. Therefore, UEAPME expects from the new European Commission and the new European Parliament support for:•binding rules in the framework of the new Capital Adequacy Directive,which ensure the transparency of rating procedures and credit scoring systems for SMEs;•Elaboration of national Codes of Conduct in order to improve the relations between Banks and SMEs and to support the adaptation of SMEs to the new financial environment.3. SMEs need an extension of credit guarantee systems with a special focus on Micro-LendingBusiness start-ups, the transfer of businesses and innovative fast growth SMEs also depended in the past very often on public support to get access to finance. Increasing risk awareness by banks and the stricter interpretation of State Aid Rules will further increase the need for public support.Already now, there are credit guarantee schemes in many countries on the limit of their capacity and too many investment projects cannot be realized by SMEs.Experiences show that Public money, spent for supporting credit guarantees systems, is a very efficient instrument and has a much higher multiplying effect than other instruments. One Euro form the European Investment Funds can stimulate 30 Euro investments in SMEs (for venture capital funds the relation is only 1:2).Therefore, UEAPME expects the new European Commission and the new European Parliament to support:•The extension of funds for national credit guarantees schemes in the framework of the new Multi-Annual Programmed for Enterprises;•The development of new instruments for securitizations of SME portfolios;•The recognition of existing and well functioning credit guarantees schemes as collateral;•More flexibility within the European Instruments, because of national differences in the situation of SME finance;•The development of credit guarantees schemes in the new Member States;•The development of an SBIC-like scheme in the Member States to close the equity gap (0.2 – 2.5 Mio Euro, according to the expert meeting on PACE on April 27 in Luxemburg).•the development of a financial support scheme to encourage the internalizations of SMEs (currently there is no scheme available at EU level: termination of JOP, fading out of JEV).4. SMEs need company and income taxation systems, whichstrengthen their capacity for self-financingMany EU Member States have company and income taxation systems with negative incentives to build-up capital within the company by re-investing their profits. This is especially true for companies, which have to pay income taxes. Already in the past tax-regimes was one of the reasons for the higher dependence of Europe’s SMEs on bank lending. In future, the result of rating w ill also depend on the amount of capital in the company; the high dependence on lending will influence the access to lending. This is a vicious cycle, which has to be broken.Even though company and income taxation falls under the competence of Member States, UEAPME asks the new European Commission and the new European Parliament to publicly support tax-reforms, which will strengthen the capacity of Crafts, Trades and SME for self-financing. Thereby, a special focus on non-corporate companies is needed.5. Risk Capital – equity financingExternal equity financing does not have a real tradition in the SME sector. On the one hand, small enterprises and family business in general have traditionally not been very open towards external equity financing and are not used to informing transparently about their business.On the other hand, many investors of venture capital and similar forms of equity finance are very reluctant regarding investing their funds in smaller companies, which is more costly than investing bigger amounts in larger companies. Furthermore it is much more difficult to set out of such investments in smaller companies.Even though equity financing will never become the main source of financing for SMEs, it is an important instrument for highly innovative start-ups and fast growing companies and it has therefore to be further developed. UEAPME sees three pillars for such an approach where policy support is needed:Availability of venture capital•The Member States should review their taxation systems in order to create incentives to invest private money in all forms of venture capital.•Guarantee instruments for equity financing should be further developed.Improve the conditions for investing venture capital into SMEs•The development of secondary markets for venture capital investments in SMEs should be supported.•Accounting Standards for SMEs should be revised in order to easetransparent exchange of information between investor and owner-manager.Owner-managers must become more aware about the need for transparency towards investors•SME owners will have to realise that in future access to external finance (venture capital or lending) will depend much more on a transparent and open exchange of information about the situation and the perspectives of their companies.•In order to fulfil the new needs for transparency, SMEs will have to use new information instruments (business plans, financial reporting, etc.) and new management instruments (risk-management, financial management, etc.).外文资料翻译涂敏之会计学 8051208076题目:未来的中小企业融资背景:中小企业融资已经改变未来的经济复苏将取决于能否工艺品,贸易和中小企业利用其潜在的增长和创造就业。

数据采集外文文献翻译中英文

数据采集外文文献翻译中英文

数据采集外文文献翻译(含:英文原文及中文译文)文献出处:Txomin Nieva. DATA ACQUISITION SYSTEMS [J]. Computers in Industry, 2013, 4(2):215-237.英文原文DATA ACQUISITION SYSTEMSTxomin NievaData acquisition systems, as the name implies, are products and/or processes used to collect information to document or analyze some phenomenon. In the simplest form, a technician logging the temperature of an oven on a piece of paper is performing data acquisition. As technology has progressed, this type of process has been simplified and made more accurate, versatile, and reliable through electronic equipment. Equipment ranges from simple recorders to sophisticated computer systems. Data acquisition products serve as a focal point in a system, tying together a wide variety of products, such as sensors that indicate temperature, flow, level, or pressure. Some common data acquisition terms are shown below.Data collection technology has made great progress in the past 30 to 40 years. For example, 40 years ago, in a well-known college laboratory, the device used to track temperature rises in bronze made of helium was composed of thermocouples, relays, interrogators, a bundle of papers, anda pencil.Today's university students are likely to automatically process and analyze data on PCs. There are many ways you can choose to collect data. The choice of which method to use depends on many factors, including the complexity of the task, the speed and accuracy you need, the evidence you want, and more. Whether simple or complex, the data acquisition system can operate and play its role.The old way of using pencils and papers is still feasible for some situations, and it is cheap, easy to obtain, quick and easy to start. All you need is to capture multiple channels of digital information (DMM) and start recording data by hand.Unfortunately, this method is prone to errors, slower acquisition of data, and requires too much human analysis. In addition, it can only collect data in a single channel; but when you use a multi-channel DMM, the system will soon become very bulky and clumsy. Accuracy depends on the level of the writer, and you may need to scale it yourself. For example, if the DMM is not equipped with a sensor that handles temperature, the old one needs to start looking for a proportion. Given these limitations, it is an acceptable method only if you need to implement a rapid experiment.Modern versions of the strip chart recorder allow you to retrieve data from multiple inputs. They provide long-term paper records of databecause the data is in graphic format and they are easy to collect data on site. Once a bar chart recorder has been set up, most recorders have enough internal intelligence to operate without an operator or computer. The disadvantages are the lack of flexibility and the relative low precision, often limited to a percentage point. You can clearly feel that there is only a small change with the pen. In the long-term monitoring of the multi-channel, the recorders can play a very good role, in addition, their value is limited. For example, they cannot interact with other devices. Other concerns are the maintenance of pens and paper, the supply of paper and the storage of data. The most important is the abuse and waste of paper. However, recorders are fairly easy to set up and operate, providing a permanent record of data for quick and easy analysis.Some benchtop DMMs offer selectable scanning capabilities. The back of the instrument has a slot to receive a scanner card that can be multiplexed for more inputs, typically 8 to 10 channels of mux. This is inherently limited in the front panel of the instrument. Its flexibility is also limited because it cannot exceed the number of available channels. External PCs usually handle data acquisition and analysis.The PC plug-in card is a single-board measurement system that uses the ISA or PCI bus to expand the slot in the PC. They often have a reading rate of up to 1000 per second. 8 to 16 channels are common, and the collected data is stored directly in the computer and then analyzed.Because the card is essentially a part of the computer, it is easy to establish the test. PC-cards are also relatively inexpensive, partly because they have since been hosted by PCs to provide energy, mechanical accessories, and user interfaces. Data collection optionsOn the downside, the PC plug-in cards often have a 12-word capacity, so you can't detect small changes in the input signal. In addition, the electronic environment within the PC is often susceptible to noise, high clock rates, and bus noise. The electronic contacts limit the accuracy of the PC card. These plug-in cards also measure a range of voltages. To measure other input signals, such as voltage, temperature, and resistance, you may need some external signal monitoring devices. Other considerations include complex calibrations and overall system costs, especially if you need to purchase additional signal monitoring devices or adapt the PC card to the card. Take this into account. If your needs change within the capabilities and limitations of the card, the PC plug-in card provides an attractive method for data collection.Data electronic recorders are typical stand-alone instruments that, once equipped with them, enable the measurement, recording, and display of data without the involvement of an operator or computer. They can handle multiple signal inputs, sometimes up to 120 channels. Accuracy rivals unrivalled desktop DMMs because it operates within a 22 word, 0.004 percent accuracy range. Some data electronic automatic recordershave the ability to measure proportionally, the inspection result is not limited by the user's definition, and the output is a control signal.One of the advantages of using data electronic loggers is their internal monitoring signals. Most can directly measure several different input signals without the need for additional signal monitoring devices. One channel can monitor thermocouples, RTDs, and voltages.Thermocouples provide valuable compensation for accurate temperature measurements. They are typically equipped with multi-channel cards. Built-in intelligent electronic data recorder helps you set the measurement period and specify the parameters for each channel. Once you set it all up, the data electronic recorder will behave like an unbeatable device. The data they store is distributed in memory and can hold 500,000 or more readings.Connecting to a PC makes it easy to transfer data to a computer for further analysis. Most data electronic recorders can be designed to be flexible and simple to configure and operate, and most provide remote location operation options via battery packs or other methods. Thanks to the A/D conversion technology, certain data electronic recorders have a lower reading rate, especially when compared with PC plug-in cards. However, a reading rate of 250 per second is relatively rare. Keep in mind that many of the phenomena that are being measured are physical in nature, such as temperature, pressure, and flow, and there are generallyfewer changes. In addition, because of the monitoring accuracy of the data electron loggers, a large amount of average reading is not necessary, just as they are often stuck on PC plug-in cards.Front-end data acquisition is often done as a module and is typically connected to a PC or controller. They are used in automated tests to collect data, control and cycle detection signals for other test equipment. Send signal test equipment spare parts. The efficiency of the front-end operation is very high, and can match the speed and accuracy with the best stand-alone instrument. Front-end data acquisition works in many models, including VXI versions such as the Agilent E1419A multi-function measurement and VXI control model, as well as a proprietary card elevator. Although the cost of front-end units has been reduced, these systems can be very expensive unless you need to provide high levels of operation, and finding their prices is prohibited. On the other hand, they do provide considerable flexibility and measurement capabilities.Good, low-cost electronic data loggers have the right number of channels (20-60 channels) and scan rates are relatively low but are common enough for most engineers. Some of the key applications include:•product features•Hot die cutting of electronic products•Test of the environmentEnvironmental monitoring•Composition characteristics•Battery testBuilding and computer capacity monitoringA new system designThe conceptual model of a universal system can be applied to the analysis phase of a specific system to better understand the problem and to specify the best solution more easily based on the specific requirements of a particular system. The conceptual model of a universal system can also be used as a starting point for designing a specific system. Therefore, using a general-purpose conceptual model will save time and reduce the cost of specific system development. To test this hypothesis, we developed DAS for railway equipment based on our generic DAS concept model. In this section, we summarize the main results and conclusions of this DAS development.We analyzed the device model package. The result of this analysis is a partial conceptual model of a system consisting of a three-tier device model. We analyzed the equipment project package in the equipment environment. Based on this analysis, we have listed a three-level item hierarchy in the conceptual model of the system. Equipment projects are specialized for individual equipment projects.We analyzed the equipment model monitoring standard package in the equipment context. One of the requirements of this system is the ability to use a predefined set of data to record specific status monitoring reports. We analyzed the equipment project monitoring standard package in the equipment environment. The requirements of the system are: (i) the ability to record condition monitoring reports and event monitoring reports corresponding to the items, which can be triggered by time triggering conditions or event triggering conditions; (ii) the definition of private and public monitoring standards; (iii) Ability to define custom and predefined train data sets. Therefore, we have introduced the "monitoring standards for equipment projects", "public standards", "special standards", "equipment monitoring standards", "equipment condition monitoring standards", "equipment project status monitoring standards and equipment project event monitoring standards, respectively Training item triggering conditions, training item time triggering conditions and training item event triggering conditions are device equipment trigger conditions, equipment item time trigger conditions and device project event trigger condition specialization; and training item data sets, training custom data Sets and trains predefined data sets, which are device project data sets, custom data sets, and specialized sets of predefined data sets.Finally, we analyzed the observations and monitoring reports in the equipment environment. The system's requirement is to recordmeasurements and category observations. In addition, status and incident monitoring reports can be recorded. Therefore, we introduce the concept of observation, measurement, classification observation and monitoring report into the conceptual model of the system.Our generic DAS concept model plays an important role in the design of DAS equipment. We use this model to better organize the data that will be used by system components. Conceptual models also make it easier to design certain components in the system. Therefore, we have an implementation in which a large number of design classes represent the concepts specified in our generic DAS conceptual model. Through an industrial example, the development of this particular DAS demonstrates the usefulness of a generic system conceptual model for developing a particular system.中文译文数据采集系统Txomin Nieva数据采集系统, 正如名字所暗示的, 是一种用来采集信息成文件或分析一些现象的产品或过程。

文献翻译-材料概述

文献翻译-材料概述

附录A外文资料:Style of materialsMaterials may be grouped in several ways. Scientists often classify materials by t heir state: solid, liquid, or gas. They also separate them into organic (once living) and inorganic (never living) materials.For industrial purposes, materials are divided into engineering materials or nonen gineering materials. Engineering materials are those used in manufacture and become parts of products.Nonengineering materials are the chemicals, fuels, lubricants, and other materials use d in the manufacturing process, which do not become part of the product.Engineering materials may be further subdivided into: ①Metal②Ceramics ③Composite ④Polymers, etcMetals and Metal AlloysMetals are elements that generally have good electrical and thermal conductivity. Many metals have high strength, high stiffness, and have good ductility.Some metals, such as iron, cobalt and nickel, are magnetic. At low temperatures, some metals and intermetallic compounds become superconductors.What is the difference between an alloy and a pure metal? Pure metals are elemen ts which come from a particular area of the periodic table. Examples of pure metals in clude copper in electrical wires and aluminum in cooking foil and beverage cans.Alloys contain more than one metallic element. Their properties can be changed b y changing the elements present in the alloy. Examples of metal alloys include stainles s steel which is an alloy of iron, nickel, and chromium; and gold jewelry which usuall y contains an alloy of gold and nickel.Why are metals and alloys used? Many metals and alloys have high densities and are used in applications which require a high mass-to-volume ratio.Some metal alloys, such as those based on aluminum, have low densities and are used in aerospace applications for fuel economy. Many alloys also have high fracture t oughness, which means they can withstand impact and are durable.What are some important properties of metals?Density is defined as a material’s mass divided by its volume. Most metals have r elatively high densities, especially compared to polymers.Materials with high densities often contain atoms with high atomic numbers, such as gold or lead. However, some metals such as aluminum or magnesium have low de nsities, and are used in applications that require other metallic properties but also requ ire low weight.Fracture toughness can be described as a m aterial’s ability to avoid fracture, espec ially when a flaw is introduced. Metals can generally contain nicks and dents without weakening very much, and are impact resistant. A football player counts on this when he trusts that his facemask won’t shatter.Plastic deformation is the ability of bend or deform before breaking. As engineers , we usuallydesign materials so that they don’t deform under normal conditions. You d on’t want your car to lean to the east after a strong west wind.However, sometimes we can take advantage of plastic deformation. The crumple zones in a car absorb energy by undergoing plastic deformation before they break. The atomic bonding of metals also affects their properties. In metals, the outer valenc e electrons are shared among all atoms, and are free to travel everywhere. Since electr ons conduct heat and electricity, metals make good cooking pans and electrical wires.It is impossible to see through metals, since these valence electrons absorb any ph otons of light which reach the metal. No photons pass through.Alloys are compounds consisting of more than one metal. Adding other metals can aff ect the density, strength, fracture toughness, plastic deformation, electrical conductivit y and environmental degradation.For example, adding a small amount of iron to aluminum will make it stronger. Al so, adding some chromium to steel will slow the rusting process, but will make it mor e brittle.Ceramics and GlassesA ceramic is often broadly defined as any inorganic nonmetallic material. By th is definition, ceramic materials would also include glasses; however, many materials s cientists add the stipulation that “ceramic” must also be crystalline.A glass is an inorganic nonmetallic material that does not have a crystalline structure. Such materials are said to be amorphous. Properties of Ceramics and GlassesSome of the useful properties of ceramics and glasses include high melting temperatur e, low density, high strength, stiffness, hardness, wear resistance, and corrosion resista nce.Many ceramics are good electrical and thermal insulators. Some ceramics have specia l properties: some ceramics are magnetic materials; some are piezoelectric materials; and a few special ceramics are superconductors at very low temperatures. Ceramics and glasses have one major drawback: they are brittle.Ceramics are not typically formed from the melt. This is because most ceramics will crack extensively (i.e. form a powder) upon cooling from the liquid state. Hence, all the simple and efficient manufacturing techniques used for glass productio n such as casting and blowing, which involve the molten state, cannot be used for the production of crystalline ceramics. Instead, “sintering” or “firing” is the process typic ally used.In sintering, ceramic powders are processed into compacted shapes and then heat ed to temperatures just below the melting point. At such temperatures, the powders re act internally to remove porosity and fully dense articles can be obtained.An optical fiber contains three layers: a core made of highly pure glass with a hig h refractive index for the light to travel, a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other s urface imperfections, and an out polymer jacket to protect the fiber from damage.In order for the core glass to have a higher refractive index than the cladding, the core glass is doped with a small, controlled amount of an impurity, or dopant, which causes light to travel slower, but does not absorb the light.Because the refractive index of the core glass is greater than that of the cladding, l ight traveling in the core glass will remain in the core glass due to total internal reflect ion as long as the light strikes the core/cladding interface at an angle greater than the critical angle. The total internal reflection phenomenon, as well as the high purity of the core glass, enables light to travel long distances with little loss of intensity. CompositesComposites are formed from two or more types of materials. Examples include p olymer/ceramic and metal/ceramic composites. Composites are used because overall p roperties of the composites are superior to those of the individual components.For example: polymer/ceramic composites have a greater modulus than the polymer c omponent, but aren’t as brittle as ceramics.Two types of composites are: fiber-reinforced composites and particle-reinforced composites.Fiber-reinforced CompositesReinforcing fibers can be made of metals, ceramics, glasses, or polymers that hav e been turned into graphite and known as carbon fibers. Fibers increase the modulus of the matrix material.The strong covalent bonds along the fiber’s length give them a very high modulus in t his direction because to break or extend the fiber the bonds must also be broken or mo ved.Fibers are difficult to process into composites, making fiberreinforced composites rel atively expensive.Fiberreinforced composites are used in some of the most advanced, and therefore most expensive sports equipment, such as a time-trial racing bicycle frame which con sists of carbon fibers in a thermoset polymer matrix.Body parts of race cars and some automobiles are composites made of glass fibers (or fiberglass) in a thermoset matrix.Fibers have a very high modulus along their axis, but have a low modulus perpendicu lar to their axis. Fiber composite manufacturers often rotate layers of fibers to avoid di rectional variations in the modulus.Particle-reinforced compositesParticles used for reinforcing include ceramics and glasses such as small mineral part icles, metal particles such as aluminum, and amorphous materials, including polym ers and carbon black.Particles are used to increase the modulus of the matrix, to decrease the permeability of the matrix, to decrease the ductility of the matrix. An example of particle-reinforce d composites is an automobile tire which has carbon black particles in a matrix of pol yisobutylene elastomeric polymer.Polymers A polymer has a repeating structure, usually based on a carbon backbon e. The repeating structure results in large chainlike molecules. Polymers are useful be cause they are lightweight, corrosion resistant, easy to process at low temperatures an d generally inexpensive.Some important characteristics of polymers include their size (or molecular weight),softening and melting points, crystallinity, and structure. The mechanical properties o f polymers generally include low strength and high toughness. Their strength is often improved using reinforced composite structures.Important Characteristics of Polymers Size. Single polymer molecules typically have molecular weights between 10,000 and 1,000,000g/molthat can be more than 2,000 re peating units depending on the polymer structure! The mechanical properties of a pol ymer are significantly affected by the molecular weight, with better engineering prop erties at higher molecular weights.Thermal transitions. The softening point (glass transition temperature) and the meltin gpoint of a polymer will determine which it will be suitable for applications. These te mperatures usually determine the upper limit for which a polymer can be used.For example, many industrially important polymers have glass transition temperatures near the boiling point of water (100℃, 212℉), and they are most useful for room temperature applications. Some specially engin eered polymers can withstand temperatures as high as 300℃(572℉). Crystallinity. Polymers can be crystalline or amorphous, but they usually have a com bination of crystalline and amorphous structures (semi-crystalline).Interchain interactions. The polymer chains can be free to slide past one another (ther mo-plastic) or they can be connected to each other with crosslinks (thermoset or elast omer). Thermo-plastics can be reformed and recycled, while thermosets and elastomer s are not reworkable.Intrachain structure. The chemical structure of the chains also has a tremendous effec t on the properties. Depending on the structure the polymer may be hydrophilic or hyd rophobic (likes or hates water), stiff or flexible, crystalline or amorphous, reactive or unreactive.The understanding of heat treatment is embraced by the broader study of metallurgy. Metallurgy is the physics, chemistry, and engineering related to metals from ore extra ction to the final product.Heat treatment is the operation of heating and cooling a metal in its solid state to chan ge its physical properties. According to the procedure used, steel can be hardened to re sist cutting action and abrasion, or it can be softened to permit machining.With the proper heat treatment internal stresses may be removed, grain size reduced, t oughness increased, or a hard surface produced on a ductile interior. The analysis of t he steel must be known because small percentages of certain elements, notably carbo n, greatly affect the physical properties.Alloy steel owe their properties to the presence of one or more elements other than ca rbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadiu m, and copper. Because of their improved physical properties they are used commerci ally in many ways not possible with carbon steels.The following discussion applies principally to the heat treatment of ordinary comme rcial steels known as plain carbon steels. With this process the rate of cooling is the c ontrolling factor, rapid cooling from above the critical range results in hard structure, whereas very slow cooling produces the opposite effect.A Simplified Iron-carbon DiagramIf we focus only on the materials normally known as steels, a simplified diagram is often used. Those portions of the ironcarbon diagram near the delta region and those above 2% carbon content are of little importance to the engineer and are deleted. A si mplified diagram, such as the one in Fig.2.1, focuses on the eutectoid region and is qu ite useful in understanding the properties and processing of steel.The key transition described in this diagram is the decomposition of single-phase aust enite(γ) to the two-phase ferrite plus carbide structure as temperature drops. Control of this reaction, which arises due to the drastically different carbon solubility of austenite and ferrite, enables a wide range of properties to be achieved through hea t treatmentTo begin to understand these processes, consider a steel of the eutectoid composition , 0.77% carbon, being slow cooled along line x-x’ in Fig.2.1. At the upper temperatur es, only austenite is present, the 0.77% carbon being dissolved in solid solution with t he iron. When the steel cools to 727℃(1341℉), several changes occur simultaneously.The iron wants to change from the FCC austenite structure to the BCC ferrite structur e, but the ferrite can only contain 0.02% carbon in solid solution.The rejected carbon forms the carbon-rich cementite intermetallic with composition F e3C. In essence, the net reaction at the eutectoid is austenite 0.77%C→ferrite 0.02% C+cementite 6.67%C.Since this chemical separation of the carbon component occurs entirely in the solid s tate, the resulting structure is a fine mechanical mixture of ferrite and cementite. Speci mens prepared by polishing and etching in a weak solution of nitric acid and alcohol r eveal the lamellar structure of alternating plates that forms on slow cooling.This structure is composed of two distinct phases, but has its own set of characteristic properties and goes by the name pearlite, because oits resemblance to mother- of- pear l at low magnification.Steels having less than the eutectoid amount of carbon (less than 0.77%) are known as hypo-eutectoid steels. Consider now the transformation of such a material represent ed by cooling along line y-y’ in Fig.2.1.At high temperatures, the material is entirely austenite, but upon cooling enters a regi on where the stable phases are ferrite and austenite. Tie-line and level-law calculation s show that low-carbon ferrite nucleates and grows, leaving the remaining austenite ri cher in carbon.At 727℃(1341℉), the austenite is of eutectoid composition (0.77% carbon) and further cooling tran sforms the remaining austenite to pearlite. The resulting structure is a mixture of prim ary or pro-eutectoid ferrite (ferrite that formed above the eutectoid reaction) and regi ons of pearlite.Hypereutectoid steels are steels that contain greater than the eutectoid amount of carb on. When such steel cools, as shown in z-z’ of Fig.2.1 the process is similar to the hyp o-eutectoid case, except that the primary or pro-eutectoid phase is now cementite inste ad of ferrite.As the carbon-rich phase forms, the remaining austenite decreases in carbon content, reaching the eutectoid composition at 727℃(1341℉). As before, any remaining austenite transforms to pearlite upon slow cooling throu gh this temperature.It should be remembered that the transitions that have been described by the phase dia grams are for equilibrium conditions, which can be approximated by slow cooling. W ith slow heating, these transitions occur in the reverse manner.However, when alloys are cooled rapidly, entirely different results may be obtained, b ecause sufficient time is not provided for the normal phase reactions to occur, in such cases, the phase diagram is no longer a useful tool for engineering analysis.HardeningHardening is the process of heating a piece of steel to a temperature within or above it s critical range and then cooling it rapidly.If the carbon content of the steel is known, the proper temperature to which the steel s hould be heated may be obtained by reference to the iron-iron carbide phase diagram. However,if the composition of the steel is unknown, a little preliminary experimentation may b e necessary to determine the range.A good procedure to follow is to heat-quench a number of small specimens of the stee l at various temperatures and observe the result, either by hardness testing or by micro scopic examination. When the correct temperature is obtained, there will be a marked change in hardness and other properties.In any heat-treating operation the rate of heating is important. Heat flows from the ext erior to the interior of steel at a definite rate. If the steel is heated too fast, the outside becomes hotter than the interior and uniform structure cannot be obtained.If a piece is irregular in shape, a slow rate is all the more essential to eliminate warpin g and cracking. The heavier the section, the longer must be the heating time to achieve uniform results.Even after the correct temperature has been reached, the piece should be held at that te mperature for a sufficient period of time to permit its thickest section to attain a unifor m temperature.The hardness obtained from a given treatment depends on the quenching rate, the carb on content, and the work size. In alloy steels the kind and amount of alloying element influences only the hardenability (the ability of the workpiece to be hardened to depth s) of the steel and does not affect the hardness except in unhardened or partially harde ned steels.Steel with low carbon content will not respond appreciably to hardening treatment. As the carbon content in steel increases up to around 0.60%, the possible hardness obtain able also increases.Above this point the hardness can be increased only slightly, because steels above the eutectoid point are made up entirely of pearlite and cementite in the annealed state. Pe arlite responds best to heat-treating operations; and steel composed mostly of pearlite can be transformed into a hard steel.As the size of parts to be hardened increases, the surface hardness decreases somewha t even though all other conditions have remained the same. There is a limit to the rateof heat flow through steel.No matter how cool the quenching medium may be, if the heat inside a large piece ca nnot escape faster than a certain critical rate, there is a definite limit to the inside hard ness. However, brine or water quenching is capable of rapidly bringing the surface of the quenched part to its own temperature and maintaining it at or close to this tempera ture.Under these circumstances there would always be some finite depth of surface hardeni ng regardless of size. This is not true in oil quenching, when the surface temperature may be high during the critical stages of quenching.TemperingSteel that has been hardened by rapid quenching is brittle and not suitable for most us es. By tempering or drawing, the hardness and brittleness may be reduced to the desir ed point for service conditions.As these properties are reduced there is also a decrease in tensile strength and an incre ase in the ductility and toughness of the steel. The operation consists of reheating que nch-hardened steel to some temperature below the critical range followed by any rate of cooling.Although this process softens steel, it differs considerably from annealing in that the p rocess lends itself to close control of the physical properties and in most cases does no t soften the steelto the extent that annealing would. The final structure obtained from tempering a fully hardened steel is called tempered martensite.Tempering is possible because of the instability of the martensite, the principal constit uent of hardened steel. Low-temperature draws, from 300℉ to 400℉ (150℃~205℃), do not cause much decrease in hardness and are used principally to relieve i nternal strains.As the tempering temperatures are increased, the breakdown of the martensite takes pl ace at a faster rate, and at about 600℉(315℃) the change to a structure called tempered martensite is very rapid. The temper ing operation may be described as one of precipitation and agglomeration or coalesce nce of cementite.A substantial precipitation of cementite begins at 600℉(315℃), which produces a decrease in hardness. Increasing the temperature causes co alescence of the carbides with continued decrease in hardness.In the process of tempering, some consideration should be given to time as well as to t emperature. Although most of the softening action occurs in the first few minutes after the temperature is reached, there is some additional reduction in hardness if the temp erature is maintained for a prolonged time.Usual practice is to heat the steel to the desired temperature and hold it there only lon g enough to have it uniformly heated.Two special processes using interrupted quenching are a form of tempering. In both, t he hardened steel is quenched in a salt bath held at a selected lower temperature befor e being allowed to cool. These processes, known as austempering and martempering, result in products having certain desirable physical properties.AnnealingThe primary purpose of annealing is to soften hard steel so that it may be machined or cold worked.This is usually accomplished by heating the steel too slightly above the critical temper ature, holding it there until the temperature of the piece is uniform throughout, and th en cooling at a slowly controlled rate so that the temperature of the surface and that of the center of the piece are approximately the same.This process is known as full annealing because it wipes out all trace of previous struc ture, refines the crystalline structure, and softens the metal. Annealing also relieves in ternal stresses previously set up in the metal.The temperature to which a given steel should be heated in annealing depends on its c omposition; for carbon steels it can be obtained readily from the partial iron-iron carbi de equilibrium diagram. When the annealing temperature has been reached, the steel s hould be held there until it is uniform throughout.This usually takes about 45min for each inch(25mm) of thickness of the largest sectio n. For maximum softness and ductility the cooling rate should be very slow, such as al lowing the parts to cool down with the furnace. The higher the carbon content, the slo wer this rate must be. The heating rate should be consistent with the size and uniformi ty of sections, so that the entire part is brought up to temperature as uniformly as possi ble.Normalizing and SpheroidizingThe process of normalizing consists of heating the steel about 50℉ to 100℉ (10℃~40℃) above the upper critical range and cooling in still air to room temperature. This process is principally used with low- and medium-carbon steels as well as alloy s teels to make the grain structure more uniform, to relieve internal stresses, or to achie ve desired results in physical properties. Most commercial steels are normalized after being rolled or cast.Spheroidizing is the process of producing a structure in which the cementite is in a sp heroidal distribution. If steel is heated slowly to a temperature just below the critical r ange and held there for a prolonged period of time, this structure will be obtained. The globular structure obtained gives improved machinability to the steel. This treatm ent is particularly useful for hypereutectoid steels that must be machined.Surface HardeningCarburizingThe oldest known method of producing a hard surface on steel is case hardening or ca rburizing. Iron at temperatures close to and above its critical temperature has an affinit y for carbon.The carbon is absorbed into the metal to form a solid solution with iron and converts t he outer surface into high-carbon steel. The carbon is gradually diffused to the interior of the part. The depth of the case depends on the time and temperature of the treatme nt.Pack carburizing consists of placing the parts to be treated in a closed container with s ome carbonaceous material such as charcoal or coke. It is a long process and used to p roduce fairly thick cases of from 0.03 to 0.16 in.(0.76~4.06mm) in depth.Steel for carburizing is usually a low-carbon steel of about 0.15% carbon that would n ot in itself responds appreciably to heat treatment. In the course of the process the out er layer is converted into high-carbon steel with a content ranging from 0.9% to 1.2% carbon.A steel with varying carbon content and, consequently, different critical temperatures r equires a special heat treatment.Because there is some grain growth in the steel during the prolonged carburizing treat ment, the work should be heated to the critical temperature of the core and then coole d, thus refining the core structure. The steel should then be reheated to a point above t he transformation range of the case and quenched to produce a hard, fine structure. The lower heat-treating temperature of the case results from the fact that hypereutecto id steels are normally austenitized for hardening just above the lower critical point. A t hird tempering treatment may be used to reduce strains.CarbonitridingCarbonitriding, sometimes known as dry cyaniding or nicarbing, is a case-hardening process in which the steel is held at a temperature above the critical range in a gaseous atmosphere from which it absorbs carbon and nitrogen.Any carbon-rich gas with ammonia can be used. The wear-resistant case produced ra nges from 0.003 to 0.030 inch(0.08~ 0.76mm) in thickness. An advantage of carbonitr iding is that the hardenability of the case is significantly increased when nitrogen is ad ded, permitting the use of low-cost steels.附录B材料的类型材料可以按多种方法分类。

外文文献翻译——顾客满意度(附原文)

外文文献翻译——顾客满意度(附原文)

外文文献翻译(附原文)译文一:韩国网上购物者满意度的决定因素摘要这篇文章的目的是确定可能导致韩国各地网上商场顾客满意的因素。

假设客户的积极认知互联网购物的有用性,安全,技术能力,客户支持和商场接口积极影响客户满意度.这也是推测,满意的顾客成为忠实的客户。

调查结果证实,客户满意度对顾客的忠诚度有显著影响,这表明,当顾客满意服务时会显示出很高的忠诚度。

我们还发现,“网上客户有关安全风险的感知交易中,客户支持,网上购物和商场接口与客户满意度呈正相关。

概念模型网上购物者可以很容易的将一个商场内的商品通过价格或质量进行排序,并且可以在不同的商场之间比较相同的产品.网上购物也可以节省时间和降低信息搜索成本。

因此,客户可能有一种感知,他们可以用更少的时间和精力得到更好的网上交易。

这个创新的系统特性已被定义为知觉有用性。

若干实证研究发现,客户感知的实用性在采用影响满意度的创新技术后得以实现。

因此,假设网上购物的知觉有用性与满意度成正相关(H1).网上客户首要关注的是涉及关于网上信用卡使用的明显的不安全感。

虽然认证系统有明显进步,但是顾客担心在网上传输信用卡号码这些敏感的信息是不会被轻易的解决的。

网上的隐私保护环境是另一个值得关注的问题。

研究表明,网上客户担心通过这些网上业务会造成身份盗窃或冒用他们的私人信息。

因此,据推测,网上购物的安全性对顾客满意度有积极地影响(H2)。

以往的研究表明,系统方面的技术,如网络速度,错误恢复能力和系统稳定性都是导致客户满意度的重要因素。

例如,Kim和Lim(2001)发现,网络速度与网上购物者的满意度有关。

Dellaert和卡恩(1999年)也报告说,当网络提供商没有进行很好的管理时网上冲浪速度慢会给评价网站内容带来负面影响。

丹尼尔和Aladwani的文件表明,系统错误的迅速准确的恢复能力以及网络速度是影响网上银行用户满意度的重要因素(H3)。

由于网上交易的非个人化性质客户查询产品和其他服务的迅速反应对客户满意度来说很重要.也有必要提供快捷交货,优质的售后服务和简便的退货程序.因此,许多网上购物商场为客户查询配备互动回答系统。

英文文献小短文(原文加汉语翻译)

英文文献小短文(原文加汉语翻译)

A fern that hyperaccumulates arsenic(这是题目,百度一下就能找到原文好,原文还有表格,我没有翻译)A hardy, versatile, fast-growing plant helps to remove arsenic from contaminated soilsContamination of soils with arsenic,which is both toxic and carcinogenic, is widespread1. We have discovered that the fern Pteris vittata (brake fern) is extremely efficient in extracting arsenic from soils and translocating it into its above-ground biomass. This plant —which, to our knowledge, is the first known arsenic hyperaccumulator as well as the first fern found to function as a hyperaccumulator— has many attributes that recommend it for use in the remediation of arsenic-contaminated soils.We found brake fern growing on a site in Central Florida contaminated with chromated copper arsenate (Fig. 1a). We analysed the fronds of plants growing at the site for total arsenic by graphite furnace atomic absorption spectroscopy. Of 14 plant species studied, only brake fern contained large amounts of arsenic (As;3,280–4,980 We collected additional samples of the plant and soil from the contaminated site –1,603 As) and from an uncontaminated site –As). Brake fern extracted arsenic efficiently from these soils into its fronds: plantsgrowing in the contaminated site contained 1,442–7,526 Arsenic and those from the uncontaminated site contained –These values are much higher than those typical for plants growing in normal soil, which contain less than of arsenic3.As well as being tolerant of soils containing as much as 1,500 arsenic, brake fern can take up large amounts of arsenic into its fronds in a short time (Table 1). Arsenic concentration in fern fronds growing in soil spiked with 1,500 Arsenic increased from to 15,861 in two weeks. Furthermore, in the same period, ferns growing in soil containing just 6 arsenic accumulated 755 Of arsenic in their fronds, a 126-fold enrichment. Arsenic concentrations in brake fernroots were less than 303 whereas those in the fronds reached 7,234 of 100 Arsenic significantly stimulated fern growth, resulting in a 40% increase in biomass compared with the control (data not shown).After 20 weeks of growth, the plant was extracted using a solution of 1:1 methanol:water to speciate arsenic with high-performance liquid chromatography–inductively coupled plasma mass spectrometry. Almost all arsenic was present as relatively toxic inorganic forms, with little detectable organoarsenic species4. The concentration of As(III) was greater in the fronds (47–80%) than in the roots %), indicating that As(V)was converted to As(III) during translocation from roots to fronds.As well as removing arsenic from soils containing different concentrations of arsenic (Table 1), brake fern also removed arsenic from soils containing different arsenic species (Fig. 1c). Again, up to 93% of the arsenic was concentrated in the fronds. Although both FeAsO4 and AlAsO4 are relatively insoluble in soils1, brake fern hyperaccumulated arsenic derived from these compounds into its fronds (136–315 levels 3–6 times greater than soil arsenic.Brake fern is mesophytic and is widely cultivated and naturalized in many areas with a mild climate. In the United States, it grows in the southeast and in southern California5. The fern is versatile and hardy, and prefers sunny (unusual for a fern) and alkaline environments (where arsenic is more available). It has considerable biomass, and is fast growing, easy to propagate,and perennial.We believe this is the first report of significant arsenic hyperaccumulation by an unmanipulated plant. Brake fern has great potential to remediate arsenic-contaminated soils cheaply and could also aid studies of arsenic uptake, translocation, speciation, distribution anddetoxification in plants.*Soil and Water Science Department, University ofFlorida, Gainesville, Florida 32611-0290, USAe-mail†Cooperative Extension Service, University ofGeorgia, Terrell County, PO Box 271, Dawson,Georgia 31742, USA‡Department of Chemistry & SoutheastEnvironmental Research Center, FloridaInternational University, Miami, Florida 33199,1. Nriagu, J. O. (ed.) Arsenic in the Environment Part 1: Cycling and Characterization (Wiley, New York, 1994).2. Brooks, R. R. (ed.) Plants that Hyperaccumulate Heavy Metals (Cambridge Univ. Press, 1998).3. Kabata-Pendias, A. & Pendias, H. in Trace Elements in Soils and Plants 203–209 (CRC, Boca Raton, 1991).4. Koch, I., Wang, L., Ollson, C. A., Cullen, W. R. & Reimer, K. J. Envir. Sci. Technol. 34, 22–26 (2000).5. Jones, D. L. Encyclopaedia of Ferns (Lothian, Melbourne, 1987).积累砷的蕨类植物耐寒,多功能,生长快速的植物,有助于从污染土壤去除砷有毒和致癌的土壤砷污染是非常广泛的。

翻译文献英文原文

翻译文献英文原文

NET-BASED TASK MANAGEMENT SYSTEMHector Garcia-Molina, Jeffrey D. Ullman, Jennifer WisdomABSTRACTIn net-based collaborative design environment, design resources become more and more varied and complex. Besides common information management systems, design resources can be organized in connection with design activities.A set of activities and resources linked by logic relations can form a task. A task has at least one objective and can be broken down into smaller ones. So a design project can be separated into many subtasks forming a hierarchical structure.Task Management System (TMS) is designed to break down these tasks and assign certain resources to its task nodes.As a result of decomposition.al1 design resources and activities could be managed via this system.KEY WORDS:Collaborative Design, Task Management System (TMS), Task Decomposition, Information Management System1 IntroductionAlong with the rapid upgrade of request for advanced design methods, more and more design tool appeared to support new design methods and forms. Design in a web environment with multi-partners being involved requires a more powerful and efficient management system .Design partners can be located everywhere over the net with their own organizations. They could be mutually independent experts or teams of tens of employees. This article discusses a task management system (TMS) which manages design activities and resources by breaking down design objectives and re-organizing design resources in connection with the activities. Comparing with common information management systems (IMS) like product data management system and document management system, TMS can manage the whole design process. It has two tiers which make it much more f1exible in structure.The lower tier consists of traditional common IMSS and the upper one fulfills logic activity management through controlling a tree-like structure, allocating design resources and makingdecisions about how to carry out a design project. Its functioning paradigm varies in different projects depending on the project’s scale and purpose. As a result of this structure, TMS can separate its data model from its logic mode1.It could bring about structure optimization and efficiency improvement, especially in a large scale project.2 Task Management in Net-Based Collaborative Design Environment2.1 Evolution of the Design EnvironmentDuring a net-based collaborative design process, designers transform their working environment from a single PC desktop to LAN, and even extend to WAN. Each design partner can be a single expert or a combination of many teams of several subjects, even if they are far away from each other geographically. In the net-based collaborative design environment, people from every terminal of the net can exchange their information interactively with each other and send data to authorized roles via their design tools. The Co Design Space is such an environment which provides a set of these tools to help design partners communicate and obtain design information. Code sign Space aims at improving the efficiency of collaborative work, making enterprises increase its sensitivity to markets and optimize the configuration of resource.2.2 Management of Resources and Activities in Net-Based Collaborative EnvironmentThe expansion of design environment also caused a new problem of how to organize the resources and design activities in that environment. As the number of design partners increases, resources also increase in direct proportion. But relations between resources increase in square ratio. To organize these resources and their relations needs an integrated management system which can recognize them and provide to designers in case of they are needed.One solution is to use special information management system (IMS).An IMS can provide database, file systems and in/out interfaces to manage a given resource. For example there are several IMS tools in Co Design Space such as Product Data Management System, Document Management System and so on. These systems can provide its special information which design users want.But the structure of design activities is much more complicated than these IM S could manage, because even a simple design project may involve different design resources such asdocuments, drafts and equipments. Not only product data or documents, design activities also need the support of organizations in design processes. This article puts forward a new design system which attempts to integrate different resources into the related design activities. That is task management system (TMS).3 Task Breakdown Model3.1 Basis of Task BreakdownWhen people set out to accomplish a project, they usually separate it into a sequence of tasks and finish them one by one. Each design project can be regarded as an aggregate of activities, roles and data. Here we define a task as a set of activities and resources and also having at least one objective. Because large tasks can be separated into small ones, if we separate a project target into several lower—level objectives, we define that the project is broken down into subtasks and each objective maps to a subtask. Obviously if each subtask is accomplished, the project is surely finished. So TMS integrates design activities and resources through planning these tasks.Net-based collaborative design mostly aims at products development. Project managers (PM) assign subtasks to designers or design teams who may locate in other cities. The designers and teams execute their own tasks under the constraints which are defined by the PM and negotiated with each other via the collaborative design environment. So the designers and teams are independent collaborative partners and have incompact coupling relationships. They are driven together only by theft design tasks. After the PM have finished decomposing the project, each designer or team leader who has been assigned with a subtask become a 1ow-class PM of his own task. And he can do the same thing as his PM done to him, re-breaking down and re-assigning tasks.So we put forward two rules for Task Breakdown in a net-based environment, incompact coupling and object-driven. Incompact coupling means the less relationship between two tasks. When two subtasks were coupled too tightly, the requirement for communication between their designers will increase a lot. Too much communication wil1 not only waste time and reduce efficiency, but also bring errors. It will become much more difficult to manage project process than usually in this situation. On the other hand every task has its own objective. From the view point of PM of a superior task each subtask could be a black box and how to execute these subtasks is unknown. The PM concerns only the results and constraints of these subtasks, and may never concern what will happen inside it.3.2 Task Breakdown MethodAccording to the above basis, a project can be separated into several subtasks. And when this separating continues, it will finally be decomposed into a task tree. Except the root of the tree is a project, all eaves and branches are subtasks. Since a design project can be separated into a task tree, all its resources can be added to it depending on their relationship. For example, a Small-Sized-Satellite.Design (3SD) project can be broken down into two design objectives as Satellite Hardware. Design (SHD) and Satellite-Software-Exploit (SSE). And it also has two teams. Design team A and design team B which we regard as design resources. When A is assigned to SSE and B to SHD. We break down the project as shown in Fig 1.It is alike to manage other resources in a project in this way. So when we define a collaborative design project’s task model, we should first claim the project’s targets. These targets include functional goals, performance goals, and quality goals and so on. Then we could confirm how to execute this project. Next we can go on to break down it. The project can be separated into two or more subtasks since there are at 1east two partners in a collaborative project. Either we could separate the project into stepwise tasks, which have time sequence relationships in case of some more complex projects and then break down the stepwise tasks according to their phase-to-phase goals.There is also another trouble in executing a task breakdown. When a task is broken into s evera1 subtasks; it is not merely “a simple sum motion” of other tasks. In most cases their subtasks could have more complex relations.To solve this problem we use constraints. There are time sequence constraint (TSC) and logic constraint (LC). The time sequence constraint defines the time relationships among subtasks. The TSC has four different types, FF, FS, SF and SS. F means finish and S presents start. If we say T abb is FS and lag four days, it means Tb should start no later than four days after Ta is finished.The logic constraint is much more complicated. It defines logic relationship among multiple tasks.Here is given an example:“Task TA is separated into three subtasks, Ta, T b and Tc. But there are two more rules.Tb and Tc can not be executed until Ta is finished.Tb and Tc can not be executed both,that means if Tb was executed, Tc should not be executed, and vice versa. This depends on the result of Ta.”So we say Tb and Tc have a logic constraint. After finishing breaking down the tasks, we canget a task tree as Fig, 2 illustrates.4 TMS Realization4.1 TMS StructureAccording to our discussion about task tree model and task breakdown basis, we can develop a Task Management System (TMS) based on Co Design Space using Java language, JSP technology and Microsoft SQL 2000. The task management system’s structure is shown in Fig. 3.TMS has four main modules namely Task Breakdown, Role Management, Statistics and Query and Data Integration. The Task Breakdown module helps users to work out task tree. Role Management module performs authentication and authorization of access control. Statistics and Query module is an extra tool for users to find more information about their task. The last Data Integration Module provides in/out interface for TMS with its peripheral environment.4.2 Key Points in System Realization4.2.1 Integration with Co Design SpaceCo Design Space is an integrated information management system which stores, shares and processes design data and provides a series of tools to support users. These tools can share all information in the database because they have a universal Data Mode1. Which is defined in an XML (extensible Markup Language) file, and has a hierarchical structure. Based on this XML structure the TMS h data mode1 definition is organized as following.<?xml version= 1.0 encoding= UTF-8’?><!--comment:Common Resource Definitions Above.The Followingare Task Design--><!ELEMENT ProductProcessResource (Prcses?, History?,AsBuiltProduct*,ItemsObj?, Changes?, ManufacturerParts?,SupplierParts?,AttachmentsObj? ,Contacts?,PartLibrary?,AdditionalAttributes*)><!ELEMENT Prcses (Prcs+) ><!ELEMENT Prcs (Prcses,PrcsNotes?,PrcsArc*,Contacts?,AdditionalAttributes*,Attachments?)><!ELEM ENT PrcsArc EMPTY><!ELEMENT PrcsNotes(PrcsNote*)><!ELEMENT PrcsNote EMPTY>Notes: Element “Pros” is a task node object, and “Process” is a task set object which contains subtask objects and is belongs to a higher class task object. One task object can have no more than one “Presses”objects. According to this definition, “Prcs” objects are organized in a tree-formation process. The other objects are resources, such as task link object (“Presage”), task notes (“Pros Notes”), and task documents (“Attachments”) .These resources are shar ed in Co Design database.。

英文文献原文及翻译

英文文献原文及翻译

外文文献翻译学生姓名:周千琪论文题目:基于的图书管理系统指导教师:武新丽技术职称:讲师原文:Visual Basic language and arithmeticThe summary of Microsoft Visual StudioMicrosoft Visual Basic (abbreviate VB) as tool the most of application program one of under Windows operating platform. No matter beginner or professional developer, VB has all offered a whole set of tools to them, Development application program that it can be relaxed and convenient. So VB as most computer first-selected the ABC of programming language of beginner." Visual" mean method to adopt visual user of development figure interface (GUI), need and write a large number of code go and describe interface appearance and position of element seldom, Tow and show controlling part that need corresponding position to get screen can help figure design interface, user of figure,; " Basic" means BASIC language, because VB is developed on the basis of already existing BAISC language.VB is a kind of programming language in common use of Microsoft, It, including VBA of the numerous Windows application software use VB language in Microsoft Excel, Microsoft Accessed., For users to carry on the secondary development; Make web page use more VBScript script language sub collection of VB too at present.Utilize data of VB visit characteristic user can establish the data base to most data base forms including Microsoft SQL Server and other enterprises data base With the application program of front, and adjustable service end part. Utilize ActiveX(TM) technology, VB can use word processor, electronic data list he Windows function that application program offers extremely, Excel of Microsoft,, Word of Microsoft,, Even can use by VB specialty edition or enterprise application program and target that edition establish directly.Integrated development environmentsIntegrated environment of VB call IDE, made up of a lot of parts , include title board, menu fence, tool fence, controlling part case, And window body window, engineering management devicewindow, attribute window, code window and window body overall arrangement window bodyoverall arrangement, etc. of designing etc.. Have covered all functions, such as design which develops the application program, editting, compiling and debugging, etc .In VB, the application program calls the project too. When start VB and open a new project for the first time, can see and pursue integrated development environment interface that show.VB come and organize development of application program through project, use project come and manage and form files of application program. One project uses the environment to make up by several window bodies, standard module generally. The system manages project through the project menu, for instance add the window body, quote . System allow turn on and manage a lot of projects besides.Visual Basic language brief introductionsBasic use and do the elementary high-level language that used often most. Its full name is Beginner' s All-purpose Symbolic Instruction Code, abbreviate as BASIC. As its name suggests, Basic one specially for language that beginner design, because it easy to learn easy to know, So the body is popular. Early Basic language to belong to and solve translating type, so can carry out line by line , So it can see the result carried out at once , this is a very convenient design for beginner. But it have concept of structure either, one that is in procedure maintain and management have as much as other language problems. But back-end Basic correct shortcoming of the above (such as Quick Basic), make it may used for and develop the large-scaler procedure too.The language is the basic composition, which forms VB procedure. VB has stipulated the form ofsentences and function.Grammar:The sentence defines incantations [Sentence body]Sentence define agree with and used in fixed function of sentence, sentence body appoint concrete content or want concrete operation that carry out of sentence. All set of sentence VB language, carry on with VB sentence organic association finish a certain specific function the procedure. Interface + procedure can solve a certain application problem.VB application program code window write in" code editing machine" generally. " editing machine of code" is like the word processing software of a piece of height specialization, there aremany easies function of writing VB code, Pursue to show [Example Ex-Hello ]In" code editing machine" code that window written.“Editing machine of code” windowDevelop the application program with Visual BasicUse VB programming, design appearance of application program first generally, write every target procedure code or other treatment procedure of incident respectively, Work of programming should be light more.The procedure of establishing the application program is as follows:Establish application program interfaceThe interface is the mutual bridge of user and procedure, Generally formed of window body and vision frame of the button, menu, text frameset. with standard WINDOWS interface of application program that VB establish. Require according to function of procedure and user and need of information interchange of procedure, Come to confirm that need those targets , plan the overall arrangement of the interface.2. Design by each attributes of target in interfaceDemand and set up each attribute of target such as appearance, name,, size of targeted. according to interface of planning.Most attribute person who fetch can set up through the attribute window when design already, Too can set up revising when operating in procedure through programming in procedure code. Have the targets respond programming by procedure code3. Respond procedure code of programming targetInterface determine appearance of procedure only, design window add codes through" code editing machine" soon after the interface, Realize some make the tasks, such as responding, information processing,etc. after accepting external message, Add code , realize some response, information processing that make after accepting external information task.4. Keep projectOne VB procedure one project, at the time of designing a application program, system will set up one be expanded and called. Project file of vbp, project file include all relevant information of file that project set up this, Keep project keep associated documents of project this at the same time. For example the window body produced when design interfaces is kept and being expanded andbeing called. Frm sum. In the window body of foxfire. At the time of opening a project( file), this project relevant files load at the same time.5. Operate and debugged by procedureOperate the procedure thoroughpin operate" selecting in the menu, when the mistake appears, VB system can offer information prompt can looked for and get rid of the mistake thoroughpin debug" within operate" menus too.6. Can produce by executive programFor make procedure can break away from VB environment, order to become next life through" file"" producing project 1.exe" of menu but executive program (eyeful), Can carry out this file directly after this. In produce, + executive program, and then through install guide bale all associated documents, Can run independently after installation under the environment of windows 9 x/2000 as a software product.Visual Basic algorithmIn computer system's any software, is by the every large or small each kind of software constituent constitution, defers to the specific algorithm to realize respectively, the algorithm quality direct decision realizes the software performance fit and unfit quality. Designs the algorithm with any method, what resources designs the algorithm to need, requires how many running time, how many storage space, how to determine an algorithm the quality, when realizes a software, is must give to solve. In computer system's operating system, the language compiling system, the database management system as well as in various computer application system's software, must use each one concrete algorithm to realize. Therefore, the algorithm design and the analysis are the computer science and a technical core question.The algorithm is the problem-solving step, we may define the algorithm Cheng Jie a determination class question the random one special method. In the computer science, the algorithm needs to use the computer algorithmic language to describe, the algorithm represents with the computer solves a kind of question precisely, the effective method. The algorithm construction of data = procedure, solves one to assign may calculate or the solvable question, the different person may compile the different procedure, solves the identical problem, here has two problems: First, with computational method close related algorithm question; Second, programming technical question. Between the algorithm and the procedure has the close relationship. The algorithm is a group has the poor rule, they had stipulated solves some specifictype question a series of operations, is to the problem solving plan accurate and the complete description. Formulates an algorithm, generally must pass through stages and so on design, confirmation, analysis, code, test, debugging, time. To algorithm study including five aspect contents:①Design algorithm. The algorithm design work is impossible completely the automation, should study the understanding already by the practice to prove that was the useful some basic algorithm design method, these basic design method was not only suitable for the computer science, moreover was suitable for domains and so on electrical engineering, operations research;② Expresses the algorithm. The description algorithm's method has many kinds of forms, for example the natural language and the algorithmic language, have the suitable environment and the characteristic respectively;③Confirms the algorithm. The algorithm confirmed the goal is causes the people to believe firmly that this algorithm can work unmistakably correctly, namely this algorithm has the circularity. The correct algorithm describes with the computer algorithmic language, constitutes the computer program, the computer program moves on the computer, obtains the algorithm operation result;④ Parsing algorithm. The algorithmic analysis is requires how many computing time and the storage space to an algorithm makes the quota the analysis. The parsing algorithm may forecast that what environment this algorithm does suit in moves effectively, to solves the identical question different algorithm validity to make the comparison;⑤Confirmation algorithm. With machine language description algorithm whether can calculate effectively, reasonable, must carry on the test to the procedure, the test order work and makes the space and time distribution map by the debugging to be composed.But the algorithm has certain characteristic, it includes:① Determinism. Algorithm each kind of operation must have the determination significance, this kind of operation should carry out what kind of movement should not to have the ambiguity, the goal is clear;②Effectiveness. Requests the operation which in the algorithm waits for realizing is basic, each kind of operation can at least completes in the principle by the human with the paper and the pen in the limited time;③ Input. An algorithm has 0 or the many inputs, before the algorithm operation starts gives the algorithm to need the data the starting value, these inputs are from the specific object set;④Output. Does for the algorithm operation result, an algorithm has or many outputs, the output has some kind of specific relational quantity with the input;⑤ Has poor. An algorithm always after carrying out had the poor step operation has terminated, namely this algorithm was may reach.Satisfies a first four characteristic group of rule not to be able to be called the algorithm, can only be called the computational process, the operating system is a computational process example, the operating system uses for to manage the computer resources, controls the manufacture industry movement, when has not made industry the movement, the computational process does not stop, but is at the waiting status.The algorithm complexity is the algorithm efficiency measure, when appraises the algorithm performance, the complexity is an important basis. The algorithm complex degree with moves computer resources how many which this algorithm needs related, needs the resources are more, indicated that this algorithm the complexity is higher; Needs the resources are less, indicated that this algorithm the complexity is lower.The spatial resources, which computer’s resources, operate most importantly, needs the time which and the stored routine and the data need, the algorithm complexity has division time complexity and the spatial complexity.The algorithm carries out the operation on the computer, needs the data which certain storage space depositing description algorithm the procedure and the algorithm need, the computer completes the operation task to require certain time. The procedure which writes according to the different algorithm places when on the computer operates, needs the time and the space are different, the algorithm complexity is needs the time and the spatial one kind of measure to the algorithm operation. The different computer its operating speed difference is very big, is weighing an algorithm the complexity to note this point.Regarding question, which assigns willfully, a profitable target which designs, the complex low algorithm is as far as possible when designs algorithm considered. Moreover, when the question, which assigns already when has many kinds of algorithms, an important criterion which choice complexity low, is when selects algorithm should follow. Therefore, the algorithm complex analysis or selects to the algorithm design has the important guiding sense and the use value.外文文献中文翻译学生姓名:周千琪论文题目:基于的图书管理系统指导教师:武新丽技术职称:讲师译文:Visual Basic 语言与算法Visual Basic的概述Microsoft Visual Basic(简称VB)是在Windows操作平台下设计应用程序的最速度、最简捷的工具之一。

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

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]。

翻译外文资料翻译译文范文

翻译外文资料翻译译文范文

翻译外文资料翻译译文范文这个样本的分析表明,买方在跨境并购中的低收益和国内兼并是相对的。

1870亿美元的收购的股东资产在宣告收购的三天内被摧毁。

这个结果揭示了造成损失的原因,因为买家跨国采购的规模变大,而且更容易遭受代理问题(默勒等,xx)。

结果还显示,估值取决于收购前期的信息收集,这影响境内收购者的决定。

买家在经营合资企业的购置资产中获得巨大的收益,可以得出,在管理资产时要从信息中获利收益。

我们假设,这些收益与被解决的不确定程度成正相关,这样的话,收购经验丰富的国家和地区,存在高层次的投资风险,也存在较高的投资回报率。

没有证据表明,购买者在较高的不确定性投资中,从闲置资本投资和有微小优势的投资中获得收益。

有微小优势的投资和分期付款的投资引致买家在国内更大的收益,但不是跨境并购。

使用股票作为支付方式与收购者的超额回报成负相关。

这些结果表明,合资企业可以作为一个过渡性的机制来减少跨境并购中的不确定性。

但是,只有一小部分资产由合资企业共同经营,这表明控制偏好(或合资企业所有权分享撤销),超过了合资企业收购前的收益。

下一节介绍了文献综述和假定。

第3节讨论样品。

第4节分析价值对收购者的影响。

第5节介绍价值的不确定性和国家投资风险。

2 文献回顾和假设2.1有关国际并购的文献此前对于跨国并购的研究,主要集中于美国买家或任何美国目标,并且对这些交易的期限和国家依靠的经济后果进行了分析。

丹尼斯等在1984年至1997年对美国企业中的44,288家比较强大的企业进行分析观察中发现全球性多元化是与企业价值的减少相关联的。

莫乐和斯克林格曼在 1985年至1995年对美国企业4430份并购分析发现投标人的经验是低收益跨国收购。

柴特吉和奥通过对英国公司的研究以及艾克波和索伯恩对 ___公司的研究也发表了类似的发现。

其他分析发现,收购回报比较小。

杜卡斯和特雷乌勒(1988)发现,平均来看,从1975年到1983年由202个美国公司所进行的301起并购并没有收获收益。

外文文献翻译原文+译文

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。

20外文文献翻译原文及译文参考样式

20外文文献翻译原文及译文参考样式

20外⽂⽂献翻译原⽂及译⽂参考样式华北电⼒⼤学科技学院毕业设计(论⽂)附件外⽂⽂献翻译学号: 0819******** 姓名:宗鹏程所在系别:机械⼯程及⾃动化专业班级:机械08K1指导教师:张超原⽂标题:Development of a High-PerformanceMagnetic Gear年⽉⽇⾼性能磁齿轮的发展1摘要:本⽂提出了⼀个⾼性能永磁齿轮的计算和测量结果。

上述分析的永磁齿轮有5.5的传动⽐,并能够提供27 Nm的⼒矩。

分析表明,由于它的弹簧扭转常数很⼩,因此需要特别重视安装了这种⾼性能永磁齿轮的系统。

上述分析的齿轮也已经被应⽤在实际中,以验证、预测其效率。

经测量,由于较⼤端齿轮传动引起的磁⼒齿轮的扭矩只有16 Nm。

⼀项关于磁齿轮效率损失的系统研究也展⽰了为什么实际⼯作效率只有81%。

⼀⼤部分磁损耗起源于轴承,因为机械故障的存在,此轴承的备⽤轴承在此时是必要的。

如果没有源于轴的少量磁泄漏,我们估计能得到⾼达96%的效率。

与传统的机械齿轮的⽐较表明,磁性齿轮具有更好的效率和单位体积较⼤扭矩。

最后,可以得出结论,本⽂的研究结果可能有助于促进传统机械齿轮向磁性齿轮发展。

关键词:有限元分析(FEA)、变速箱,⾼转矩密度,磁性齿轮。

⼀、导⾔由于永久磁铁能产⽣磁通和磁⼒,虽然⼏个世纪过去了,许多⼈仍然着迷于永久磁铁。

,在过去20年的复兴阶段,正是这些优点已经使得永久磁铁在很多实际中⼴泛的应⽤,包括在起重机,扬声器,接头领域,尤其是在永久磁铁电机⽅⾯。

其中对永磁铁的复兴最常见于效率和转矩密度由于永磁铁的应⽤显著提⾼的⼩型机器的领域。

在永久磁铁没有获取⾼度重视的⼀个领域是传动装置的领域,也就是说,磁⼒联轴器不被⼴泛⽤于传动装置。

磁性联轴器基本上可以被视为以传动⽐为1:1磁⼒齿轮。

相⽐标准电⽓机器有约10kN m/m的扭矩,装有⾼能量永久磁铁的磁耦有⾮常⾼的单位体积密度的扭矩,变化范围⼤约300–400 kN 。

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技术文献资料翻译专业艺术设计(环艺方向)学生姓名董海娟班级 BM环艺091学号 0951406113指导教师裴慧芳专业系主任王庆勇发放日期2013年2月23日Introduction to modern hotel designAbstract:Modern hotel is not a simple can imagine space. It not only includes many practical connotation, more gradually become the symbol of people and the whole city culture grade. New hotels are no longer as in the past, only to meet a very simple purpose of have a rest, so more and more hotel operators begin to attach importance to the design. Hotel space design will take you to review the design of the related research and the hot issues, and put forward their views on the hotel design planning.一、The hotel design concept and ideaAt present domestic hotel design concept and idea for the study does not see more, so, in the field of hotel the same is true in the field of architecture. Hotel design, is based on the hardware design of the hotel building, electrical and mechanical, interior decoration, furniture, lighting, lighting design, etc. Hotel space design identity design is set accommodation, catering, entertainment, office, etc. Design of an integrated environment. From the environment can be divided into the indoor environment and outdoor environment; Is divided into from the function of accommodation, catering, entertainment, office, shopping malls and other places; Space and public space and private space, at the same time, the space space also can be divided into closed, semi-closed and open. Hotel design including the location, shape, civil, electrical, decoration and hotel management from six aspects, the hotel design should be accurate according to the hotel overall planning and design. The type of hotel design is a kind of commercial culture, as a cultural venues, transportation centers, office space, medical rehabilitation, is a kind of social demand, that is culture, has its cultural attributes. Successful hotel design is not only meet the needs of its use function, the design is novel, more important is to have the different regional and cultural. Hotel design elements, there are a lot of aspects, the function is the most important, in the same topic space, function and harmonious development of cultural elements, has become a growing trend. Cultural quality is the soul of hotel design. Hotel design scope not only includes the total planning, architecture, landscape,interior decoration, equipment installation, the hardware, also including the function layout, process planning, cultural orientation, business analysis, image planning, these software. Good design must be fully embody the concept of five, namely, humanity, practical, advanced, economical and artistic quality. Agree with "people-oriented" design concept will become an important direction of the development of the modern hotel design. Design concept is based on people-oriented, to the owner. Hotel design and construction of regional culture. Internationally, the design of the hotel in general is divided into the following several aspects: architectural design, structural design, equipment design, interior design. Hotel design is a complicated system engineering, it involves architectural, mechanical and electrical engineering, management science, economics, aesthetics, information engineering, psychology, finance various aspects knowledge, and the hotel itself unique management pattern and so on. Many different style of the hotel operators involved in the mastery of their own hotel design concept, is the pursuit of a unique corporate culture idea, set up their own unique style. Internationally accepted standard of hotel design is divided into the principle and application demand of two parts, and always in constant development. This includes the total planning, construction, equipment, facilities and interior design, including the orientation of culture, management, market research and development.二、China's history, present situation and trend of the hotel design research1.The hotel design history of ChinaAbout the history of Chinese hotel design, different scholars understanding of its classification is not consistent. YanYu think Chinese understanding and the understanding of the hotel design began from more than two decades ago, the original hotel is believed to be a show place of luxury, is the sign of a rich, so the time of the hotel design generally choose high-grade materials such as marble, granite, wool carpet, to create an environment for the nobility and wealth of people yearning, emphasis on environmental effects on people. YanYu the evolution of the design development of the hotel design, summarized to two main line, is a functional space structure from single to satisfy travelers of the accomodation development for today's meet the needs of all kinds of people more and more complex - one can live, work,party, entertainment, leisure, dining, shopping, and various activities, the other one is the hotel's decorative art development, increasingly refined decoration craft, design innovation, from the trival adornment, the concise co-existence, from the character of the show to culture. It is considered that hotel design in China is accompanied with the process of reform and opening up started and developed slowly, can be divided into three periods: the 70 s and 1950 s design does not have its own restaurant, almost few designs but also in the 1950 s Russian classical mixed with symbols of Chinese traditional decoration design style; After the 1980 s, with the rapid development of China's economy, the domestic hotel industry has entered a stage of rapid development. But at the same time, China's hotel design was still in the stage of simple imitation of "follow suit", there is no outstanding personality in terms of color; After the 1990 s, the international hotel group, with its design style diversity trend was to follow, they let people appreciate the design professional, see of the gap between our hotel design in China are in the direction of the specialization. YanYu design from the perspective of the decorative arts appreciation, roughly divided into three stages of development. Early stage: is outside of the hotel management idea and the adornment design completely follow "takes doctrine". Lead author much by Hong Kong or foreign designers. Domestic basic didn't decoration design professionals, design concept is relatively backward, and the finished product is only limited to cad or refined decoration construction drawing design category; High speed development stage: in the early ninety s. The rapid development of economy, to the adornment of the domestic design industry has brought the good opportunity. A large number of elite engaged in architecture and art discipline devoted himself into the wave. Some colleges and universities have also timely set up relevant professional, through the study of advanced foreign technology and art, in nearly a decade of practice process, experience learning, imitation, drain and discard the growth of the journey. Show in front of works, present a is a scene of flowers, to which the wheat from the chaff to evaluate these works is one-sided, it is important at this time for the all-round development of domestic interior decoration design laid a solid talent base. It's historical significance far beyond value to the design work itself; Get to phase: it wasdivided in the 21st century. Objectively speaking, this stage is not complete, more accurate say is ongoing. In the recent five to six years of decoration works, whether in the functional design level and the market concept and management concept of press close to, or in the technical level to use intelligent technology content and the ability to grasp new materials to improve, or artistic style level multicultural flavor and decoration of the four-walled character of the play, all tightly button up the high speed development in the era pulse, and industrial technology development and the emergence of new materials are closely linked.2.The status quo of Chinese hotel designIn modern hotel interview, Wang Yi believes that China has no real sense of the hotel building design education system, and only pay attention to outward appearance design, rather than from the perspective of the user, the function of cohesion within the hotel and use convenience into consideration in the future. Only consider the hotel design enough "class", quite beautiful in all kinds of top grade material to hotel installed on fashionable garment, ignoring the inner functions of cohesion and use of human, ignoring the demand for the long-standing development of the hotel. YanYu think design, hotel design under the influence of the traditional concept of "face", the present trend of one-sided pursuit of "luxury". Yang Zhen thought, most of the hotel design in China is simple "copycat" level. But three experts acknowledge that China's domestic hotel design strength is growing fast. YanYu design think hotel design in China compared with developed countries is still in its infancy. There are many problems and shortcomings. Severely restricted the further development of our country's hotel industry. China hotel design is still in the imitation of foreign original stage, it is difficult to have their own characteristics. Some hotels have realised that imitation is not blindly, introduced a variety of personalized and humanized services, however, underneath the essence has not changed.3.The hotel design trendYanYu to design thought has the following a few big characteristics:de-emphasis dignitaries luxury; Give more space to the toilet; Reduce the amount of restaurant (individual does market hotel except); Compression of public area andoutstanding personalized; Avoid extravagance, advocating simplicity; Hotel construction and renovation of technology costs increase, but the total cost can't break through. Mr Barton, durkheim cuny, introduced the hotel planning and design of new buildings and the environment trend is: the life taste and design; House guest demand design; Safety design, emphasis on the functional requirement of the hotel background design; Has a comprehensive application of hotel design. YanYu design identity barton, Mr Kim, deterioration, and think that the brand effect is also a new trend. New trend is: return to nature, the pursuit of large area of Shared space; Guest room toilet area expanded, decorate luxurious, functional diversification; Pursuit of multi-functional, tend to diversification. Into the "people-oriented" design concept; . Highlight the personalized design; Pay attention to new technology and new equipment applications. Consumption based on the basic theory of economics, the Angle of consumption culture as the guidance, hotel design trend of the current detailed induction and analysis, think that due to the influence of the western developed countries, hotel development has a tendency to convergence with the developed countries, humanized and professional hotel consumption, ecological consumption and green hotel, hotel consumption information and intelligence, consumer culture theme hotel, and consumption of the brand and brand hotel, the hotel consumption characterization and characteristics. Some predict the hotel design will be more to cater to the guests' expectations, everywhere reflect a kind of huma n care; Will pay more attention to the rate of return on investment; Will be more reflect local characteristics; In the trend of diversification nakedness culture grade.三、The influence of the design and management of the hotelGood design show the hotel's elegant fashion and noble quality to bring good business at the same time also let hotel become the focus of concern of the public. Good design through to deduce new ideas and trends, so as to improve the building structure and change the city architecture. It can even active hotel around a region's economy. Family to think, good hotel design can give a guest a novelty, a kind of like mood of The Times, can effectively arouse the guest's consumption desire, to show the quality of maverick style, and have not culture kernel hook model, played apositive role to the promotion of hotel management benefit. Hotel provides guests with not only the overall design style is convenient and comfortable living environment, more important is to provide people with the spirit of enjoyment, increase the hotel's cultural taste. Hotel design style brings good returns for the business, bring a high occupancy rate, attract the guest and improve the room revenue. Rational design layout for the hotel to reduce the manpower and energy costs, and improve the operation efficiency. X full and clear thought, good hotel design by humanized detail processing and upgrade the room comfort level to improve the occupancy rate and enhanced profitability; Good design goes through the huma nized design gimmick with reasonable distribution of funds to extend the life of the hardware is extending project of transformation period, to save investment and enhance profitability. Modern hotel interview, only make design combined with operation, can make more customers loyal to the hotel, to bring more benefits in the hotel. Design and management of the hotel have a symbiotic relationship directly. The authors come to the hotel is designed to meet the demand of mental space of human settlements, which interact with the operation and management, coordination in the whole hotel operation system. Scientific and modern management for hotels in the market competition provides a strong guarantee; Appropriate, suitable hotel design is effective and efficient management operation has played a positive catalytic effect. The two complement each other, in the modern hotel own comprehensive strength competition plays an important role.四、ConclusionWith the continuous development of China's hotel industry, the competition between the hotel is also more and more fierce. A hotel wants to win the guests should be more when the guests enter the hotel the first step to give him leave deep memory, this is very important. Design the success to build a hotel and the environment is very harmonious whole has become a factor decides the success or failure of the hotel management, hotel professional design gradually put into agenda. As China's economy continued rapid development, domestic and international consumer market increasingly mature and expand the development of China's hoteldesign, not only closely to the international development trend, more too, advanced development, from behind./article/i27887524.html。

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