Addendum to On fibre space structures of a projective irreducible symplectic manifold

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有关火山的英语作文

The Majestic Power of VolcanoesVolcanoes,nature's formidable architects,stand as monumental testaments to Earth's dynamic interior.These geological colossi are not only awe-inspiring landmarks but also pivotal players in Earth's long history,sculpting landscapes,influencing climates,and nurturing life in their shadow.This essay delves into the essence of volcanoes,exploring their formation,eruptions,and the profound impact they have on our planet and its inhabitants.The Formation of VolcanoesVolcanoes are born from the fiery depths of Earth's mantle.When tectonic plates diverge or converge,they create pathways for magma to rise through the crust.This molten rock,seeking escape,finds its way to the surface,forming volcanoes.Over time,successive eruptions build up layers of lava and ash,giving rise to the classic conical shape of many volcanoes,though their forms can vary widely from steep stratovolcanoes to broad shield volcanoes.The Spectacle of EruptionsVolcanic eruptions are among the most spectacular and powerful natural events on our planet.They can manifest as gentle lava flows that create new land,or as explosive eruptions that spew ash,gas,and volcanic bombs into the atmosphere.The type of eruption largely depends on the magma's composition and the volcano's vent structure.While eruptions can cause destruction,they also play a crucial role in Earth's geologic and biological processes,creating fertile soils and affecting global climates.Impact on the Environment and HumanityVolcanoes exert a profound influence on their surroundings.Volcanic soils,enriched by ash and minerals,are incredibly fertile,supporting lush vegetation and agriculture.Many civilizations have thrived in the shadows of volcanoes,drawn by the rich land and the minerals found within.However,the power of volcanoes can also bring devastation.Eruptions can obliterate landscapes,bury towns in ash,and trigger tsunamis and climate change.The1815eruption of Mount Tambora in Indonesia led to the"Year Without a Summer,"causing widespread crop failures and famine across the globe.Despite their potential for destruction,volcanoes are also a source of renewable energy.Geothermal energy harnessed from volcanic areas provides a clean,sustainable power source that can reduce our reliance on fossil fuels.Living with VolcanoesFor communities living near volcanoes,the threat of eruption is a constant presence.Yet,through advances in volcanology and monitoring technologies,scientists can now better predict eruptions,saving lives and minimizing damage.People have learned to coexist with these fiery giants,respecting their power while benefiting from their bounty.ConclusionVolcanoes,with their majestic beauty and terrifying power,are stark reminders of Earth's vibrant,ever-changing nature.They challenge us to understand and respect the forces that shape our world.As we continue to unlock their secrets,we learn not only about the Earth's past but also about how to live more harmoniously with our planet's dynamic systems. Volcanoes,for all their fury,underscore the interconnectedness of Earth's processes and the delicate balance of life on our planet.。

3D培养间充质干细胞

Dynamic perfusion bioreactor system for3D culture of rat bone marrow mesenchymal stem cells on nanohydroxyapatite/polyamide 66scaffold in vitroXu Qian,1Fang Yuan,1Zhu Zhimin,2Mo Anchun31State Key Laboratory of Oral Diseases,Sichuan University,Chengdu,610041,People’s Republic of China2Department of Prosthodontics,West China College of Stomatology,Sichuan University,Chengdu,610064,People’s Republic of China3Department of Oral implant,West China College of Stomatology,Sichuan University,Chengdu,610041,People’s Republic of ChinaReceived3September2012;revised4December2012;accepted11December2012Published online in Wiley Online Library().DOI:10.1002/jbm.b.32894Abstract:The aim of the study was to investigate the biocom-patibility and osteogenic effectiveness of the porous nanohy-droxyapatite/polyamide66(n-HA/PA66)scaffold material that was cultured with the rat bone marrow mesenchymal stem cells(rBMSCs),under the static culture condition and the dynamic perfusion culture condition in vitro,and to investi-gate whether the3D perfusion culture condition was better in provoking proliferation of rBMSCs than the3D static culture condition.The Methyl thiazolyl tetrazolium(MTT)assay,alka-line phosphatase(ALP)activity assay,Osteocalcin(OCN) assay and scanning electron microscope(SEM)were used to observe the proliferation and differentiation of rBMSCs.The samples were respectively harvested at1st,3rd,7th,14th,and 21st days and effect comparisons were made between the two of the culture conditions.The results showed that values of MTT,ALP,and OCN were increased continuously and revealed a signiﬁcant difference between the two culture con-ditions(p<0.05).On the14th day,SEM revealed calciﬁed nodules2–8l m in diameter in the lamellar structure.Under the static culture condition,the pores were covered with the cells looking like a piece of blanket,but under the perfusion culture condition the cells were observed to have a3D lamel-lar structure.In conclusion,the porous n-HA/PA66scaffold material can be used as a good candidate material for the bone scaffold construction in the tissue engineering because of its excellent3D structure,which can greatly improve the proliferation and differentiation of rBMSCs and make them proliferate and osteogenesis even better under the perfusion culture condition.V C2013Wiley Periodicals,Inc.J Biomed Mater Res Part B:Appl Biomater00B:000–000,2013.Key Words:bone graft,nanohydroxyapatite/polyamide66 (n-HA/PA66)scaffold,porosity,perfusion bioreactor,dynamic culture,tissue engineeringHow to cite this article:Qian X,Yuan F,Zhimin Z,Anchun M.2013.Dynamic perfusion bioreactor system for3D culture of rat bone marrow mesenchymal stem cells on nanohydroxyapatite/polyamide66scaffold in vitro.J Biomed Mater Res Part B2013:00B:000–000.INTRODUCTIONThe majority of factors such as dental extraction,periodontal disease,trauma and tumor can lead to some defective changes in the hard tissues.1Repair and reconstruction of the bone defects are the most difﬁcult procedures in the dental treat-ment.Therefore,the bone grafts and the alveolar reconstruc-tion scaffold materials are widely used in the dental clinical practice.The scaffolds play an important role to direct and provide support to the growth of cells and serve as a matrix of the tissue formation during the bone tissue regeneration.This kind of role has well been recognized and the scaffolds have widely been used in the bone tissue engineering.Hydroxyapatite(HA)is an ideal bioactive material because of its excellent osteoconductivity and osteoinductivity.The composition and structure are similar to those of the natural bones,and it can be directly bonded to the bone tissues in vivo.2However,some factors such as abrasion resistance and corrosion resistance have limited its clinical application.3,4 Hence,the balance between the degradation and the regener-ation is very important,and the construction of the cells scaf-fold can provide a continuous structural support and make the bones able to bear a sufﬁcient load in their function performances.Polyamide(PA)has good biocompatibility with the human tissues because its chemical structure is similar to that of the bone collagen protein.So,it has been widely used in the bio-materials for clinical medicine,for example,used as a surgical suture material,which has been used for nearly50years. However,the degradation of PA is difﬁcult to control.To overcome this shortage,a novel porous nanohydroxyapatite/Correspondence to:M.Anchun;e-mail:moanchun@ or Z.Zhimin;e-mail:zzhimin@V C2013WILEY PERIODICALS,INC.1polyamide 66(n-HA/PA66)has been developed,which is syn-thesized from hydroxyapatite and polyamide,foamed by the thermal pressing and the injection molding techniques.5As our previous article stated,its great porosity and proper pore size can facilitate the cell seeding,survival,growth,prolifera-tion and differentiation in vivo.6In order to provide an enough theoretical support for its clinical application,we should per-form a further research on the n-HA/PA66scaffold in vitro .The bone tissue engineering is a promising technique,which can promote the development related to the bone scaffold materials,seed cells,culture bioreactor,and so forth.All the researches are based on a new concept of creating a similar microenvironment for the bone formation and har-vesting the biggest biological activity of the tissue engi-neered bones.7The bone marrow mesenchymal stem cells (BMSCs),also called the bone marrow stromal cells (BMSCs),have become the most potential seed cells because of their relative easiness to obtain,their ampliﬁcation phenotype sta-bility,and their avoidance of excessive bone abnormal prolif-eration and avoidance of the related medical ethics dis-pute.8–10In addition,the culture bioreactors can imitate the living environment in vivo ,such as the rotating wall bioreac-tor and the perfusion bioreactor.11,12Since the biomechani-cal stimulation is an important inﬂuence factor of inducing BMSCs to differentiate into the osteoblastic cells.The bio-reactor systems can alleviate the nutrient transfer limita-tion,13upregulate the osteoblastic markers,13,14and increase the calcium deposition.15Therefore,this study was designed to investigate the reactiveness of the rBMSCs in vitro to eval-uate the biocompatibility and the osteogenic effectiveness of the n-HA/PA66scaffold material under the static culture condition and the dynamic perfusion culture condition in vitro ,and to investigate whether the dynamic culture condi-tion can better provoke the proliferation of rBMSCs in vitro .MATERIALS AND METHODSMaterials and characterizationThe porous n-HA/PA66scaffold materials (Figure 1)were synthesized from nanohydroxyapatite and polyamide,foamed by the thermal pressing and the injection moldingtechniques.5The bending strength,tensile strength and compressive strength of the composite with 64.5%n-HA content were 90–95,75–85,and 110–125MPa,respectively,which were similar to those of the natural bone (80–100,60–120,50–140MPa).5,16The elastic modulus of the com-posite was 5–7GPa,which was similar to that of the natural bone (3–25GPa).The pore size was 300-500l m in diame-ter and the porosity was 65–75%.There were 40pieces of materials to guarantee the comparability of the testing data.Mesenchymal stem cell donorAll animal procedures were performed according to the guidelines made by Animal Ethics Committee of Sichuan University.All experiments were conformed to the interna-tional guidelines on the ethical use of animals.We mini-mized the number of the rats used in the study and mini-mized their sufferings as much as possible.rBMSCs were isolated from the 4-week-old male or female Sprague Dawley (SD)rats 140–160g in weight,which had been purchased from Experimental Animal Cen-ter of Sichuan University.Isolation and culture of rBMSCsrBMSCs were harvested from the femur and the tibiae of the SD rats according to the protocol modiﬁed by Soleimani and Nadri.17The femur and the tibiae were placed in peni-cillin-streptomycin (Gibco,100U/ml)for 5minutes.Then,the bone marrow was ﬂushed by Minimum Essential Me-dium Alpha Medium (a -MEM,Gibco,USA),which was sup-plemented by 10%(v/v)FBS (Gibco,Australia),using an 18gauge needle.Then,the cell suspension was transferred to the tissue culture ﬂasks in a 37 C-5%CO 2incubator.The medium was poured half and the fresh medium was added 24hours later.After 48hours,the medium was replaced by the fresh medium,and the non-adherent cells were removed but the adherent cells were left for the culture in a mono-layer.The initial adherent cells were deﬁned as Passage 0(P0)cells.The culture medium was refreshed every 3days until the adherent cells became conﬂuent.Then,the P0cells were trypsinized (0.25%trypsin,Sigma,USA),washedandFIGURE 1.The surface topograph of the n-HA/PA66scaffold material.A:The material size was prepared as 16mm in diameter and 1.5mm in thickness for each experiment.One hole 2.5mm and three holes 1.5mm in diameter were drilled in the material,which better beneﬁted the cul-ture medium passing through.Then,sterilization was performed by irradiation of Co 60.B:The material was magniﬁed 10times for better obser-vation on the pores.n-HA/PA66:nanohydroxyapatite/polyamide 66.[Color ﬁgure can be viewed in the online issue,which is available at .]2QIAN ET AL.DYNAMIC PERFUSION BIOREACTOR SYSTEMplated into the other tissue culture ﬂasks.rBMSCs were cul-tured to Passage 3(P3)for use in the following experimen-tal procedures.Flow cytometryP3rBMSCs were trypsinized and stained with monoclonal antibodies (CD44,CD29,CD45,CD11b,CD34)at room tem-perature for 30min.9,10Then the P3rBMSCs were per-formed by ﬂow cytometry (China)analysis to identify the phenotypes before the experiments using.Mesenchymal multipotential differentiationP3rBMSCs were trypsinized,washed,and plated into the other tissue culture ﬂasks with the osteogenic and adipo-genic inductive a -MEM medium (Gibco,USA)at a density of 2Â104cells/cm 2in a 37 C-5%CO 2incubator for the Alzarin red staining and oil red staining.Cell proliferation assayP3rBMSCs were trypsinized,washed and seeded on the 40pieces of n-HA/PA66scaffold material at a density of 5Â104cells /cm 2with osteogenic inductive medium in a 37 C-5%CO 2incubator for 24h.When the cells were adhered to the scaffold closely,they were equal separatedfor the following two culture conditions:the static culture condition (Figure 2)and the dynamic perfusion culture con-dition (Figures 3and 4),both with osteogenic inductive me-dium.Then,those sample cells underwent the following examinations:MTT assay,ALP activity,OCN detection assay,and SEM.Analysis of cell proliferation by MTT assayThe MTT assay is a colorimetric test for measuring the cell viability,cell proliferation,and cytotoxicity.The MTT substance is reduced by mitochondrial dehydrogenase in the living cells to a blue-colored formazan precipitate.This pre-cipitate can be dissolved by dimethylsulfoxide (DMSO,sigma,USA)and monitored by Thermo Scientiﬁc Varioskan Flash (Finland),a proxy for the cell proliferation.18In brief,MTT was ﬁrst prepared as a stock solution of 5g/L in phosphate buffer and was ﬁltered.MTT was added on the 1st ,3rd ,7th ,14th and 21st days respectively and dissolved by DMSO repeatedly.Then wash precipitate in the pores as much as possible and take out the scaffolds,the data were analyzed as absorbance at 570nm for the comparison between the static culture condition and the dynamic perfusion culturecondition.FIGURE 2.The stainless wire bent to ﬁx the material to prevent its ﬂoating in the culture medium.Before rBMSCs were seeded,the material was soaked in the medium for 48h.rBMSCs:the rat bone marrow mesenchymal stem cells.[Color ﬁgure can be viewed in the online issue,which is available at.]FIGURE 3.Structure of the dynamic perfusion bioreactor.The dynamic perfusion bioreactor consisting of a peristaltic pump,a tubing circuit,a medium reservoir and a perfusion cartridge.The system was divided into two parts,that is,the medium circulation part and the gas exchange part.In the medium circulation part,the peristaltic pump perfused the medium out of the medium reservoir and,then,into the perfusion car-tridge.After that,the medium returned to the medium reservoir and experienced this circulation repeatedly.The ﬂow velocity of the peristaltic pump was regulated at 2mL/min.In the gas exchange part,the mixed air contained 5%CO 2,21%O 2and 75%N 2according to the requirement of the cell culture.The mixed air passed through the bacterial ﬁlter at a speed of 60bubbles per minute.The safety bottle was placed at the end of the circulation part to guarantee the airway unobstructed.[Color ﬁgure can be viewed in the online issue,which is available at .]ORIGINAL RESEARCH REPORTJOURNAL OF BIOMEDICAL MATERIALS RESEARCH B:APPLIED BIOMATERIALS |MONTH 2013VOL 00B,ISSUE 003ALP activity assayALP decomposes p-nitrobenzene phosphate (PNPP)into p-nitrophenol (PNP)under the relevant conditions,which reﬂects the degree of the cell activity according to the shade of yellow of PNP .The ALP activity was performed at 405nm using PNPP (Sigma,USA)as the substrate.The optical density (OD)value reﬂected the PNP generation at each minute.HTS 7000Plus High-Efﬁcient Analyzer (USA)determined the OD value every 60seconds for 4times and calculated the absorbance changes (D A).According to the formula,the ALP activity (U/ml)was ﬁg-ured out.The total protein content was determined by the Coo-massie brilliant blue method.Then,the ALP activity was expressed as U/mg (unit per mg of protein).Brieﬂy,all the sam-ples in the static culture group and the dynamic culture group were collected respectively on the 1st ,3rd ,7th ,14th and 21st days.Cells were rinsed two times with PBS followed by trypsini-zation and then scraped into ddH 2O.All samples were followed by three cycles of freezing and thawing.The ALP activity values were determined by the method mentioned above.OCN detection assayThe OCN enzyme linked immunosorbent assay (ELISA)kits were used to detect the OCN levels.In the two culture groups,the culture medium was collected for determination of the OCN levels.The samples were harvested respectively on the 1st,3rd,7th,14th,and 21st days.Absorbance of each well was measured at 450nm by HTS 7000Plus.SEM observationThe samples were harvested respectively on the 1st,3rd,7th,14th,and 21st days under the two culture conditions.Then,the samples were soaked in 2.5%glutaraldehydeovernight,and the alcohol gradient dehydration was pre-pared for the SEM observation.The samples were sliced into two pieces to be convenient for observing the pores inside and the surface of both sides of scaffolds.Statistical analysisThere were at least 90pieces of materials to guarantee the comparability of the testing data,half for static condition and half for dynamic condition.Each 3pieces for ALP assay,MTT assay and SEM observation on 1,3,7,14,and 21days.The samples were harvested respectively.All the data were expressed as mean 6standard error (SE).Comparisons were performed by a paired two-tailed distribution test between the two culture conditions.Values of p <0.05were considered statistically signiﬁcant.RESULTSCharacterization of rBMSCsCulture expanded rBMSCs grew as slender spindle-like or star-like cells [Figure 5(A)].Under permissive culture condi-tions,rBMSCs underwent osteogenic and adipogenic differ-entiation,which conﬁrming their bona-ﬁde MSC phenotype [Figure 5(B–D)].The majority of rBMSCs at P3were positive for CD44(99.6%)and CD29(99.8%),while a few cells were positive for CD45(4.8%),CD11b (0.6%)and CD34(0.4%)(Figure 6).It indicated that high-purity rBMSCs could be harvested and used in the next experiment.MTT assayIn Figure 7,the curves indicated a rising pattern for the MTT values of the two culture results.In spite of the MTT value on the 3th day of the static culture seemed alittleFIGURE 4.A,B:The scaffolds seeded with rBMSCs,which were separated by the bent stainless wires to prevent the cell injury due to the fric-tion between the materials.C:There were 10pieces of materials inside one perfusion culture chamber.To guarantee the comparability of the testing data,the materials located at the same position in the perfusion cartridge should be sent to the same test determination.Each 3pieces for ALP assay,MTT assay and SEM observation on 1,3,7,14and 21days.The samples were harvested respectively.ALP:alkaline phosphatase,MTT:Methyl thiazolyl tetrazolium,SEM:scanning electronic microscopy.[Color ﬁgure can be viewed in the online issue,which is available at .]4QIAN ET AL.DYNAMIC PERFUSION BIOREACTOR SYSTEMgreater than that of the dynamic perfusion culture,but no statistically signiﬁcant difference was found between the two cultures (p >0.05);however,observations on the 14th and the 21st days showed that the MTT value of the dynamic culture exceeded the static culture,and there was a signiﬁcant difference between the two groups (p <0.05).ALP assayFigure 8showed that on the 7th day the peak of ALP values were observed under the two culture conditions but after that time the falling trend of the values was found under the both conditions.The statistical analysis showed that there was signiﬁcant difference in the ALP values according to the observations on the 3rd,7th,14th,and 21st days except for the observation on the 1st day (p <0.05).OCN assayFigure 9showed that the OCN values obtained under the two-culture conditions showed a rising trend during the ob-servation period.Under the two culture conditions,the OCN values were signiﬁcantly greater on the 21st day than on the 3rd,7th,and 14th days (p <0.05).A statistically signiﬁ-cant difference was found in the OCN values between the two-culture conditions on the 3rd day (p ¼0.0075),14th day (p ¼0.007)and 21st day (p ¼0.001);however,on the 7th day no signiﬁcant difference was found between the two culture conditions (p ¼0.703).SEM observationThe SEM results from the static culture revealed that rBMSCs uniformly spread on the surface of scaffold after 24h of culture [Figure 10(A)].The pseudopods stretched on the pore walls,the pore size of which was 300–500l m in diameter,and the porosity was 65–75%.6On the 3rd day af-ter the cell seeding,the cells began to grow on the edge of the pores,proliferated well and connected with the other cells [Figure 10(B)].On the 7th day,the cells on the pore edge proliferated layer upon layer,looking like apavedFIGURE 5.Characterization of rBMSCs.A:Primary rBMSCs were slender spindle-like or star-like cells.B:Mineralized nodules formed after 14days of the mineralization inductive culture.C:rBMSCs were induced for 21days of the ontogenetic inductive culture.Mineralized nodules were reddish orange dyed by the Alzarin red staining.D:rBMSCs were induced for 5days of the adipogenic inductive culture.Lipid Droplet was red-dish dyed by oil red staining.E:rBMSCs grew well at the margin of the n-HA/PA66scaffold.The viability of rBMSCs around n-HA/PA66was strong though calciﬁcation was occasionally found.[Color ﬁgure can be viewed in the online issue,which is available at.]FIGURE 6.rBMSCs phenotype identiﬁcation by ﬂow cytometry.The majority of rBMSCs at P3were positive for CD44(99.6%)and CD29(99.8%),while a few cells were positive for CD45(4.8%),CD11b (0.6%)and CD34(0.4%).[Color ﬁgure can be viewed in the online issue,which is avail-able at .]ORIGINAL RESEARCH REPORTJOURNAL OF BIOMEDICAL MATERIALS RESEARCH B:APPLIED BIOMATERIALS |MONTH 2013VOL 00B,ISSUE 005blanket.However,the cells at the bottom and on the walls of the pores had less nutrition supply.Therefore,the cells became smaller in number or even died [Figure 10(C)].On the 14th day,the pores were completely covered by the cells looking like a paved blanket [Figure 10(D)].The SEM results revealed that under the dynamic perfu-sion culture condition,rBMSCs were better adhered to the surface of the scaffolds.The cells spread on the rim and the inner wall of the pores after the 24-h perfusion culture.On the 3rd day,the proliferated cells spread on the deep pores and connected with each other [Figure 11(A)].rBMSCs became denser and denser in arrangement,and they were proliferated along with the porous stereoscopic structure af-ter 7days [Figure 11(B)].The cells growing vigorously for 14days remained at the bottom and on the inner wall of the pores.In the static culture group,the pores were covered by the cells looking like a paved blanket;however,in the dynamic perfusion culture group,the cells were shaped like the 3D lamellar structure which simulated to the shape of scaffold [Figure 11(C)].Majority of the pores were opened and unobstructed,so that the exchange of air and nutrients could be guaranteed.In the lamellar structure,calciﬁed nod-ules 2-8l m in diameter could be observed [Figure 11(D)].DISCUSSIONSBMSCs are not only involved in the hematopoietic stem cell survival and differentiation but also have a multiplex differ-entiation potential.Since BMSCs are relatively few in the bone marrow,they have to be puriﬁed and cultivated to meet the bone tissue engineering requirement.The puriﬁca-tion process usually includes the cell adherence separation,density gradient centrifugation,19immune magnetic beads separation,20and ﬂow cytometry.21The monoclonal anti-body magnetic beads separation system and the ﬂow cytom-etry require not only good experimental conditions but also a great amount of bone marrow;therefore,the maintaining of the BMSCs activity is relatively difﬁcult.The gradient density centrifugation can harvest highly pure cells but the centrifugal speed and time have to be exactly adjusted in the different environmental conditions.So,in this study we used a mature method,i.e.,the cell adherence separation for ampliﬁcation of BMSCs.This method had been proved effec-tive in the previous studies.BMSCs were proliferated on the walls but the hematopoietic cells were proliferated in the medium.Non-adherent cells were removed and the adher-ent cells were left for the culture in a monolayer along with the procedure of refreshing the medium.At last,BMSCs were trypsinized for 3or 4passages and they were puri-ﬁed.22The majority of BMSCs at P3phenotype identiﬁcation by ﬂow cytometry indicated that high-purity BMSCs could be harvested and used in the experiment.The natural bone material was considered as nanocompo-site material,which was composed of collagen,apatite,and water;one-third was inorganic and two-thirds was organic.The bending strength,tensile strength and compressive strength of the porous n-HA/PA66scaffold material were 90–95,75–85,and 110–125MPa,respectively.5The porous n-HA/PA66scaffold material was close to the natural bone material that has the similar bending strength,tensile strength,and compressive strength (80–100,60–120,50–140MPa).16There-fore,this kind of composite can be well matched to that of the human bones.5PA had good biocompatibility with the human tissues,probably because of its similar chemical structure to that of the collagen protein.The polarity of the amide keys and the carboxy of PA could guide the tissue and cell growth,and promote the osteoid formation and mineralization.5PA had an excellent biological activity,biocompatibility and bone conduc-tion property.23n-HA/PA66also had excellentmechanicalFIGURE 7.The MTT values obtained under the static culture condi-tion and the dynamic perfusion culture condition for 1,3,7,14,and 21days.*p <0.05.[Color ﬁgure can be viewed in the online issue,which is available at.]FIGURE 8.The ALP values obtained under the static culture condition and the dynamic perfusion culture condition for 1,3,7,14,and 21days.*p <0.05.[Color ﬁgure can be viewed in the online issue,which is available at.]FIGURE 9.The OCN values obtained under the static culture condi-tion and the dynamic perfusion culture condition for 1,3,7,14,and 21days.*p <0.05.[Color ﬁgure can be viewed in the online issue,which is available at .]6QIAN ET AL.DYNAMIC PERFUSION BIOREACTOR SYSTEMcompatibility,and its mechanical strength came mainly from the hydrogen bond between carboxyl of n-HA and acylamino of PA66.The content of n-HA more or less affected the stability of the hydrogen bond and the crystallization rate of PA66,and thus affected the strength of n-HA/PA66.n-HA/PA66foamed by the thermal pressing and the injection molding techniques had the uniform pore size (diameter,300-500l m),which pro-vided a lasting stress-absorbent core framework.19The speciﬁc surface area of the porous n-HA/PA66scaffold had a large con-tact region,which facilitated adhesion,differentiation,prolifera-tion and metabolization of the cells.6The 3D scaffold structure effectively stimulated the osteoblast differentiationandFIGURE 10.The SEM observation on rBMSCs under the static culturecondition.FIGURE 11.The SEM observation on rBMSCs under the dynamic perfusion culture condition.ORIGINAL RESEARCH REPORTJOURNAL OF BIOMEDICAL MATERIALS RESEARCH B:APPLIED BIOMATERIALS |MONTH 2013VOL 00B,ISSUE 007beneﬁted the osteoprogenitor cell proliferation and migra-tion.24,25Another experiment successfully proved that the3D porous scaffold effectively promoted the extracellular matrix synthesis,and its structure was similar to the natural bone structure.26After rBMSCs were seeded on the scaffolds,they were cultured under the two conditions,that is,the static culture condition and the dynamic perfusion culture condition. Under the static culture condition,rBMSCs were proliferated on the surface or out of the scaffolds because of the gravity action.27rBMSCs in the scaffolds only accounted for25%of the initially cultivated rBMSCs because the culture medium and the gas molecules could not be effectively transferred to the deep pores,so that the cell proliferation and mineral-ization only existed in the scaffold surface120–250l m in depth21;therefore,there was little or no bone formation at the centre of the scaffolds.28The structure of the3D scaf-fold met the tissue engineering requirement,but the static culture condition became an unfavorable factor.22In order to imitate the living environment in vivo,quite a few bio-reactors were developed.Glowacki et al.performed some experiments to prove the dynamic perfusion culture condi-tion able to increase the viability and the functions of BMSCs.29The cells could be seeded well-proportionally inside and outside of the scaffolds by the3D dynamic perfu-sion culture condition,which could promote oxygen and nutrients to enter the scaffolds so that the sufﬁcient prolif-eration of the cells inside the scaffolds could be guaranteed.Many of the previous researches showed that the proper shear force and the mechanical distractive force could pro-mote the BMSCs osteogenic differentiation.There were many force application systems used for this purpose,for example,the four-point bending model,30the rotating wall bioreactor,31and the perfusion bioreactor.29The dynamic perfusion bioreactor used in this experiment perfused oxy-gen and carbon dioxide into the pores to guarantee the cul-ture medium circulation and nutrition exchanges.We chose aﬂow velocity of2ml/min to promote the cell proliferation and differentiation in our previous experiment because that the velocity was not so fast to cause rBMSCs away from the scaffolds.Compared with the3D static culture condition in this experiment,the3D dynamic perfusion culture condition could make the values of MTT,ALP,and OCN increase con-tinuously.However,the MTT value on the3th day of the static culture seemed a little greater than that of the dynamic perfusion culture,but observations on the14th and the21st days showed that the MTT value of the dynamic culture exceeded the static culture condition obvi-ously.The ALP activity examination could show a signiﬁcant difference between the two-culture conditions on the3rd, 7th,14th,and21st days.The OCN value obtained under the dynamic perfusion culture condition was greater than that obtained under the static culture condition on the14th and 21st days.All the results indicated that the3D dynamic per-fusion culture condition could induce osteogenesis more effectively,which were similar to the results from other pre-vious researches.32The SEM results showed that under the static culture condition,the mass of the cells was shaped like a paved blanket on the scaffold surface,and most of the pores were covered by the so-called blanket.It was difﬁcult toﬁnd rBMSCs existing in the pores,but some dead cells were observed there.The reason for thoseﬁndings was probably that the material exchange level was relatively low in that place,so that the cells had to proliferate on the nu-trient-rich liquid surface,forming the structure like a paved blanket.However,under the dynamic perfusion culture con-dition,rBMSCs formed a3D layer structure,and the cells could be clearly observed at the bottom or on the sides of the pore walls.Some liquid was observed to beﬂowing across the pores,so that the cells could obtain sufﬁcient nutrients,which was a beneﬁcial factor for the cell prolifer-ation.Some calciﬁed nodules2-8l m in diameter could be found in the lamellar structure on the14th day,which revealed that porous n-HA/PA66could increase the calcium matrix deposition and the differentiation speed of the late-stage osteoblast.In addition,n-HA/PA66with65%-75% interconnected porosity had a greater calcium deposition rate than the other materials with a lower porosity.As the preosteoblast line was seeded in the scaffold that was9 mm in diameter and5mm in height,the central oxygen concentration would drop to0%on the5th day of the cul-ture[33].The cell death was observed subsequently in those areas of the scaffold.When the demineralized bone matrix scaffold was placed under the dynamic perfusion cul-ture condition,the central oxygen concentration increased to4%.Although this oxygen concentration level was still lower than that under the bulk medium condition(20%),it was still enough for prevention of the cell death.13 CONCLUSIONSThe innovative bone tissue-engineering porous n-HA/PA66 scaffold material is an ideal three-dimensional micro-struc-ture material for sufﬁcient proliferation of rBMSCs.The po-rous n-HA/PA66scaffold material is conﬁrmed to be a good candidate as a bone scaffold material used in the tissue en-gineering.And the dynamic perfusion culture condition can greatly improve proliferation and osteogenic effectiveness of rBMSCs on porous n-HA/PA66scaffold. ACKNOWLEDGMENTSThe authors are grateful to Ms.Li Xiaoyu at the State Key Labo-ratory of Oral Diseases(West China College of Stomatology) for her assistance in the cell culture and Dr.Zhu Zhimin(West China College of Stomatology)for her assistance in the experi-ment implementation.REFERENCES1.Mecall RA,Rosenfeld AL.The inﬂuence of residual ridge resorp-tion patterns onﬁxture placement and tooth position.1.Int J Periodontics Restorative Dent1991;11:8–23.2.Woodard JR,Hilldore AJ,Lan SK,Park CJ,Morgan AW,EurellJA,Clark SG,Wheeler MB,Jamison RD,Wagoner Johnson AJ.The mechanical properties and osteoconductivity of hydroxyapa-tite bone scaffolds with multi-scale porosity.Biomaterials2007;28:45–54.3.Strocchi R,Orsini G,Lezzi G,Scarano A,Rubini C,Pecora G,Piat-telli A.Bone regeneration with calcium sulfate:Evidence for8QIAN ET AL.DYNAMIC PERFUSION BIOREACTOR SYSTEM。

机械英语专业名词

机械专业英语词汇（很全）金属切削 metal cutting 机床 machine tool 金属工艺学 technology of metals 刀具 cutter 摩擦 friction 联结 link传动 drive/transmission 轴 shaft 弹性 elasticity频率特性 frequency characteristic 误差 error响应 response 定位 allocation 机床夹具 jig动力学 dynamic 运动学 kinematic 静力学 static分析力学 analyse mechanics 拉伸 pulling压缩 hitting 剪切 shear 扭转 twist 弯曲应力 bending stress强度 intensity 三相交流电 three-phase AC磁路 magnetic circles 变压器 transformer异步电动机 asynchronous motor 几何形状 geometrical精度 precision 正弦形的 sinusoid 交流电路 AC circuit机械加工余量 machining allowance 变形力 deforming force变形 deformation 应力 stress 硬度 rigidity热处理 heat treatment 退火 anneal 正火 normalizing脱碳 decarburization 渗碳 carburization电路 circuit 半导体元件 semiconductor element反馈 feedback 发生器 generator直流电源 DC electrical source门电路 gate circuit 逻辑代数 logic algebra外圆磨削 external grinding内圆磨削 internal grinding 平面磨削 plane grinding变速箱 gearbox 离合器 clutch 绞孔 fraising绞刀 reamer 螺纹加工 thread processing螺钉 screw 铣削 mill 铣刀 milling cutter功率 power 工件 workpiece 齿轮加工 gear mechining齿轮 gear 主运动 main movement主运动方向 direction of main movement进给方向 direction of feed 进给运动 feed movement合成进给运动 resultant movement of feed合成切削运动 resultant movement of cutting合成切削运动方向 direction of resultant movement of cutting 切削深度 cutting depth 前刀面 rake face刀尖 nose of tool 前角 rake angle后角clearance angle 龙门刨削planing 主轴spindle 主轴箱headstock卡盘chuck 加工中心machining center 车刀lathe tool车床lathe 钻削镗削bore 车削turning 磨床grinder 基准benchmark钳工locksmith 锻forge 压模stamping 焊weld 拉床broaching machine拉孔broaching 装配assembling 铸造found 流体动力学fluid dynamics流体力学fluid mechanics 加工machining 液压hydraulic pressure切线tangent 机电一体化mechanotronics mechanical-electrical integration气压air pressure pneumatic pressure 稳定性stability介质medium 液压驱动泵fluid clutch液压泵hydraulic pump 阀门valve 失效invalidation 强度intensity载荷load 应力stress 安全系数safty factor 可靠性reliability螺纹thread 螺旋helix 键spline 销pin 滚动轴承rolling bearing滑动轴承sliding bearing 弹簧spring 制动器arrester brake十字结联轴节crosshead 联轴器coupling 链chain 皮带strap精加工finish machining 粗加工rough machining变速箱体gearbox casing 腐蚀rust 氧化oxidation磨损wear 耐用度durability 随机信号random signal离散信号discrete signal 超声传感器ultrasonic sensor集成电路integrate circuit 挡板orifice plate残余应力residual stress 套筒sleeve 扭力torsion 冷加工cold machining 电动机electromotor 汽缸cylinder 过盈配合interference fit热加工hotwork 摄像头CCD camera 倒角rounding chamfer优化设计optimal design 工业造型设计industrial moulding design有限元finite element 滚齿hobbing 插齿gear shaping伺服电机actuating motor 铣床milling machine钻床drill machine 镗床boring machine 步进电机stepper motor丝杠screw rod 导轨lead rail 组件subassembly可编程序逻辑控制器Programmable Logic Controller PLC电火花加工electric spark machining电火花线切割加工electrical discharge wire - cutting相图phase diagram 热处理heat treatment固态相变solid state phase changes有色金属nonferrous metal 陶瓷ceramics 合成纤维synthetic fibre电化学腐蚀electrochemical corrosion 车架automotive chassis悬架suspension 转向器redirector 变速器speed changer板料冲压sheet metal parts 孔加工spot facing machining车间workshop 工程技术人员engineer 气动夹紧pneuma lock数学模型mathematical model 画法几何descriptive geometry机械制图Mechanical drawing 投影projection视图view 剖视图profile chart 标准件standard component零件图part drawing 装配图assembly drawing尺寸标注size marking 技术要求technical requirements刚度rigidity 内力internal force 位移displacement截面section 疲劳极限fatigue limit 断裂fracture塑性变形plastic distortion 脆性材料brittleness material刚度准则rigidity criterion 垫圈washer 垫片spacer直齿圆柱齿轮straight toothed spur gear 斜齿圆柱齿轮helical-spur gear 直齿锥齿轮straight bevel gear 运动简图kinematic sketch齿轮齿条pinion and rack 蜗杆蜗轮worm and worm gear虚约束passive constraint 曲柄crank 摇杆racker凸轮cams 共轭曲线conjugate curve 范成法generation method定义域definitional domain值域range 导数\微分differential coefficient求导derivation 定积分definite integral不定积分indefinite integral 曲率curvature 偏微分partial differential毛坯rough 游标卡尺slide caliper 千分尺micrometer calipers攻丝tap 二阶行列式second order determinant逆矩阵inverse matrix 线性方程组linear equations概率probability 随机变量random variable排列组合permutation and combination 气体状态方程equation of state of gas 动能kinetic energy 势能potential energy机械能守恒conservation of mechanical energy动量momentum 桁架truss 轴线axes 余子式cofactor逻辑电路logic circuit 触发器flip-flop 脉冲波形pulse shape数模digital analogy 液压传动机构fluid drive mechanism机械零件mechanical parts 淬火冷却quench 淬火hardening回火tempering 调质hardening and tempering 磨粒abrasive grain结合剂bonding agent 砂轮grinding wheel(be)qualfied, up to grade 合格abnormal engine noise diagnosis equipment 异响诊断仪abnormal handling 异常处理abnormal knocking 异响abrasion wear; scratching 磨损abrasive belt grinding machine 砂带磨床abrasive belt gringding 砂带磨削abscissa 横坐标AC arc welding machine 交流弧焊机accelerated run 赶点acceleration 加速度acceleration analysis 加速度分析acceleration diagram 加速度曲线accidental defect 事故性缺陷acetylene 乙炔acetylene cylinder 乙炔罐acetylene generator 乙炔发生器acetylene-welding installation 乙炔氧焊装置add lubricating oil 加润滑油addendum 齿顶高addendum circle 齿顶圆addition to standard 标准补充件additional element 附加要素additon agent 添加剂adhesion 粘附adjustable speed motors 调速电动机adjusting 调整administration/general affairs dept 总务部administration/general affairs dept 总务部admisistration of vehicle amintenance 汽车维修管理admisistrative standard 管理标准adopting by equation 等同采用adopting by equivalent 等效采用adopting by reference 参照采用adoption of international standard and advanced oversea standard 采用国际标准和国外先进标准after dripping （柴油喷射系）渗漏滴油ageing 老化ageing 时效aims of standardization 标准化的目的air circuit breaker 空气断路器air dry 自然干燥air jarring moulding machine 气动震实造型机air pipe 气管air seal 气幕air spray gun 空气喷枪air spring 空气弹簧air terminal 航空集散站air tool 风动工具air-conditioning equipment 车厢空调设备air-cushion eject-rod 气垫顶杆airless spray equipment 无空气喷涂设备alcohol 乙醇alcohol container 沾湿台alcohols solvent 醇类溶剂aligning 校正alkalidipping 脱脂alkali-earth babbitt 碱土巴氏合金alkaline degreasing 碱法脱脂alkaline etch 龄咬allowable amount of unbalance 许用不平衡量allowable pressure angle 许用压力角allowable stress; permissible stress 许用应力alloy cast iron 合金铸铁alloy structureal steel 合金结构钢alloy tool steel 合金工具钢alternation switch 转换开关alumel 铝镍合金aluminied steel sheet 渗铝钢板aluminium bronze 铝青铜aluminium casting alloy 铸造铝合金aluminizing 渗铝aluminum powder paint 铝粉漆（银色漆）amended draft 修正草案amendment to standard 标准修改件amino plastics 氨基塑料amino-filler 氨基腻子amount of unbalance 不平衡量amplitude of vibration 振幅analog-mode device 类模器analysis of mechanism 机构分析analytical design 解析设计analytical method 分析法angle of contact 包角angular acceleration 角加速度angular contact ball bearing 角接触球轴承angular contact bearing 角接触轴承angular contact radial bearing 角接触向心轴承angular contact thrust bearing 角接触推力轴承angular velocity 角速度angular velocity ratio 角速比anion electrophoretic coating 阴离子型电泳涂料anneal 退火annealing 退火annealing box 退火箱annealing furnace 退火炉annealing oven 退火炉annex 附录annular ball baring 径向球轴承annular spring 环形弹簧anode mechanical working 阳极机械加工Anodize 阳性处理anolyte 阳极电解液anticorrosive bimetal 耐蚀双金属anticorrosive paint 防蚀漆anti-foaming additive 防泡沫添加剂antifoaming agent 消泡剂antifouling paint(copper paint) 防污漆anti-freeze additive 防冻添加剂antifriction alloy 减摩合金antifriction alloy 减摩合金antifriction bearng 减摩轴承anti-friction quality 减摩性anti-knock compound 抗爆剂antirust paint 防锈漆anti-tarnish treatment 抗暗处理aperiodic speed fluctuation 非周期性速度波动appended description of standard 标准附加说明application factor 工况系数applied force 作用力approved by 核准approved by / checked by / prepared by 核准/审核/承办aqua regia 王水arc welding machine 电弧焊机Archimedes worm 阿基米德蜗杆archives of standardization 标准化档案Arctan 反正切argon arc welding 氩弧焊argon welding 氩焊arm 臂部armature tester 电枢试验器artery 干线articulated bus 通道式公共汽车articulated equipment 铰接装置articulated trolly bus 通道式无轨电车artificial drying 人工干燥artificial gasoline 人造汽油artificial leather 人造胶革artificial resin 人造树胶artificial wool 人造羊毛asbestos 石棉asbestos band 石棉带asbestos board 石棉板asbestos fiber 石棉纤维asbestos linen 石棉布asbestos paper 石棉纸asbestos steel leaf 石棉钢片asbestos web 石棉织物as-deposited strength 焊后强度aseptic 防腐剂assembling clearance 装配间隙assembly 组装assembly condition 装配条件Assembly line 组装线Assembly line 组装线assistant manager 助理assistant manager 助理Assur group 杆组as-welded 焊态atlas 图册、图谱atomosphere quality standard 大气质量标准attendant seat 乘务员座椅augular offset 角度偏差ausforming 形变热处理austenite 奥氏体authority 权力机构autoclino 自动壳型机automatic box splitter 自动分箱机automatic closer 自动合箱机automatic compensating device for boring cutter wear 镗刀磨损自动补偿装置automatic gas cutting 自动气割automatic headstock changing N/C machine 自动更换主轴箱数控机床automatic inspection machine for piston ring tension 活塞环弹性自动检验机automatic instruction calling device 自动指令呼叫装置automatic line for weighting connecting rod 连杆称重去重自动线automatic moulding productio line ofr cylinder block 缸体自动造型生产线automatic multi-stage cold fromer 多工位自动冷镦机automatic plating machine 自动电镀装置automatic production line for automobile final drive housing 汽车主减速器壳加工自动线automatic production line for connecting rod 连杆加工自动线automatic production line for cranshaft dynamic balance 曲轴动平衡自动线automatic production line for cylinder block 气缸体加工自动线automatic production line for cylinder head 气缸盖加工自动线automatic production line for gas carburization 气体渗碳自动线automatic screwdriver 电动启子automatic sprayer 自动喷漆机automatic ticket checker 自动检票机automatic tool changing N/C machine 自动换刀数控机床automatic welding 自动焊接automation 自动化automobile transportation enterprise 汽车运输企业automotive alcquer 汽车用喷漆automotive enamel 汽车漆automotive topcoat 汽车面漆auxiliary fuction 辅助功能available material 良品可使用average days during major repair of vehicles 汽车大修平均在修车日average days in plant during major of vehicles 汽车大修平均在厂车日average interval mileage of major repair of vehicles 汽车大修间隔里程average main-hours of vehicle maintenance and repair 汽车维修平均工时average stress 平均应力average tonnage (passenger seat) 平均吨（客）位average velocity 平均速度avional 铝合金axial contact bearing 轴向接触轴承axial direction 轴向axial internal clearance 轴向游隙axial load 轴向载荷axial load factor 轴向载荷系数axial plane 轴向平面axial thrust load 轴向分力axial tooth profile 轴向齿廓axle stand 轮轴架babbit metal 巴氏合金back cone 背锥back cone angle 背锥角back cone distance 背锥距back fire 回火back flow 回流backlash 侧隙backlash 齿侧间隙backlash 间隙back-to-back arrangement 背对背安装bad condition of vehicle 汽车不良状况baffle plate 挡块bainite 贝氏体bakelite 胶木（电木）baking paint 烘漆balance 平衡balance of mechanism 机构平衡balance of rotor 转子平衡balance of rotors 回转体平衡balance of shaking force 惯性力平衡balancing centering machine 平衡-钻中心孔机床balancing machine 平衡机balancing mass 平衡质量balancing quality 平衡品质balancing speed 平衡转速balata 巴拉塔树胶balata spring 橡胶弹簧ball 球ball bearing 球轴承ball bearing 球轴承ball screw 滚珠丝杆band brake 带式制动器band-aid 创可贴bar stock cutting by punching 冲压下料barcode 条码barcode 条码barcode 条码barcode scanner 条码扫描器barcode scanner 条码扫描器barrel (cylindric) cam 圆柱式凸轮步进运动机构barrel plating 滚镀bar-type cylinder gauge 杆式气缸量规base circle 基圆base cone 基圆锥base cylinder 基圆柱base pitch 基圆齿距basic dynamic axial load rating 轴向基本额定动载荷basic dynamic radial load rating 径向基本额定动载荷basic international standard 基础国际标准basic rating life 基本额定寿命basic standard 基础标准basic static axial load rating 轴向基本额定静载荷basic static radial load tating 径向基本额定静载荷basic terms 基本术语basket 蝴蝶竺batch furnace 分批炉battery hydrometer 蓄电池液体比累计battery welder 蓄电池式焊机be put in storage 入库beacon 警示灯bead 焊道bead cracking 焊道裂纹bead welding 堆焊beading stress 弯曲应力bearing 轴承bearing alloy 轴承合金bearing block 轴承座bearing bore diameter 轴承内径bearing bush 轴瓦、轴承衬bearing cap 轴承盖bearing capacity 承载能力bearing capacity factor 承载量系数bearing clearance 轴承间隙bearing cone 轴承内圈bearing cup 轴承盖bearing cup 轴承外圈bearing height 轴承高度bearing life 轴承寿命bearing metal 轴承合金bearing outside diameter 轴承外径bearing race 轴承座圈bearing saddle 轴承座bearing score 拉瓦bearing shell 轴瓦bearing shim 轴承垫片bearing steel 轴承钢bearing width 轴承宽度beeswax 蜂蜡behind schedule 晚点belleville spring 碟形弹簧belt driving 带传动belt pulley 带轮bender 弯曲机bending die 压弯模bending moment 弯矩bending press 压弯机bending-beading die 压弯压筋模bending-curling die 压弯卷圆模bending-flanging die 压弯翻边模beryllium bronze 铍青铜bevel gear 锥齿轮bevel gears 圆锥齿轮机构bevel pulley; bevel wheel 锥轮bezel 斜视规bezel panel 面板bezel panel 面板bibliography 文献书目bilaterally harmonized standard 双边协调标准biliographical reference 书目参考目录bimetal strip from tin-aluminium alloy 高锡铝合金双金属带binder 粘合剂bisector 平分线bituminous paint 沥青漆black box 黑箱black washer 黑皮垫圈blacksmith welding 锻焊blank 齿轮轮坯blank 轮坯blank 制坯blanker 落料机blanking 穿落模blanking die 落料模blanking-coining die 落料压印模blanking-slotting die 落料切槽模blend solvent 溶合溶剂blinster 气泡block diagram 框图block hammer 落锤blow-by 串气blow-by meter 曲轴箱窜气量测定仪blower 鼓风机blueing 发蓝处理blush 导色board 看板body bumping tool 车身修整工具body guidance mechanism 刚体导引机构body of a normative document 一个标准文件的主体bold line 粗线bolt 螺栓bone gum 骨胶booth 喷漆室boring 镗boring 镗削boring hole 镗孔boron steel 硼钢boronizing 渗硼bottom clearance 顶隙bottom die(counter die) 下模boundary dimension 外形尺寸box furnace(muffle furnace) 马弗炉box molding machine 有箱造型机boxing 环焊bracket 小磁导brake 制动器brake bleeder 制动系空气排除器brake depresor 制动踏板压下器brake drum lathe 制动鼓车床brake fade 制动失效brake flusher 制动液自动更换装置brake shoe grinder 制动蹄片磨削装置branch 支线branch line 岔线brass 黄铜brazing by flame 火焰钎焊breakdown 断裂bridge type baking oven 桥式烘干室bright coating 光亮镀层bright washer 光垫圈brightener 光亮剂brittleness 脆性broaching 拉削broaching gear 拉齿bronze 青铜bulk goods 散装货物burn rubber 轮胎烧耗burning 烧伤burnishing 磨光（抛光0 burnishing 抛光burr(金属)毛边flash(塑件)毛边bus bay 港湾式车站bus priority sytem 公共汽车bus priority sytem 公共汽车优先通行系统bus shelter 候车亭bushing block 衬套business law and regulation 企业法规butt resistance welding 电阻对焊butt seam welding 滚对焊butt welding 对接焊buttress thread form 锯齿形螺纹buzzle 蜂鸣器cabin 客舱cable bracket 电缆托架cadmium bronze 镉青铜cage 保持架calcium carbide 电石calculated bending moment 计算弯矩cam 凸轮cam , cam mechanism 凸轮机构cam block 滑块cam driver 铡楔cam profile 实际廓线cam profile 凸轮廓线cam with oscillating follower 摆动从动件凸轮机构camber gauge 外倾测量器camphor 樟脑camsahft coping lathe 凸轮轴仿形车床camshaft grinding machine 凸轮轴磨床camshaft polishing machine 凸轮轴超精磨机床camshaft polishing machine 凸轮轴抛光机床camshaft(journal )turning lathe 凸轮轴（轴颈）车床cantilever beam 悬臂梁cantilever structure 悬臂结构capability 能力car row 车列car stand (jack stand) 汽车架carbide to water generator 投入式乙发生器carbon arc welding 碳弧焊carbon electrode 碳极carbon fouling （火花塞）积碳carbon structureal steel 普通碳素结构钢carbon tool steel 碳素工具钢carbon-fiber reinforced plastics 碳纤维增强塑料carbonitriding (cyaniding) 碳氮共渗（氰化）carbonization 碳化carburetor icing 化油器结冰carburizing 渗碳carburizing alloy steel 渗碳合金钢carburizing carbon steel 渗碳碳素钢carburizing furnace 渗碳炉card of goods 货卡carriage 车厢Cartesian coordinate manipulator 直角坐标操作器carton 纸箱carton box 纸箱cascade speed control 串级调速case-based design,CBD 基于实例设计cash fare 普通票casing head gasoline 气体汽油cast bronze 锻造青铜cast iron 铸铁cast steel 铸钢catalog 目录cathode shiedl 阴极罩catholyte 阴极电解液cating machine 浇注机cation electrophoretic coating 阳离子型电泳涂料cause analysis 原因分析cause description 原因说明cavitation 穴蚀cellophane 赛璐酚celluloid 赛璐珞cellulose acetate 醋酸纤维（脂）cement gum 胶泥cementite 渗碳体center distance 中心距center distance change 中心距变动center of mass 质心center of pressure 压力中心centerless grinding 无心磨削central gear 中心轮centralized transportation 集中运输centrifugal force 离心力centrifugal force 向心力centrifugal seal 离心密封centrifugal stress 离心应力cetane number 十六烷值chain 链chain 链条chain 链条槽chain dotted line 点划线chain gearing 链传动装置chamfer 倒角chamois 麂皮change gear change wheel 变速齿轮character die 字模characteristics 特性chartered vehicle 包车chassis 底座chassis 基座chassis 基座chassis dynamometer 底盘测功机chassis lubricator 底盘润滑机check nut 锁紧螺母checked by 初审check-up 技术检查chemical -heat treatment 化学热处理chemical mechanical working 化学机械加工chemical vaporous depositon 化学气相沉积法chemical wear 化学磨损chilled cast rion 冷激铸铁chloroprene rubber 氯丁橡胶Chromate 铬酸处理chrome bronze 铬青铜chromel 铬镍合金chuck for grinding hole and end face of bevel gear 磨圆锥齿轮孔和端面用的卡盘circuit breaker cabinet 断路器柜circular bending die 压圆模circular gear 圆形齿轮circular pitch 齿距circular pitch; pitch of teeth 节距circular thickness 圆弧齿厚circulating power load 循环功率流circulation 周转city monthly ticket 市区月票city passenger flow 市区客流city transposrtation 市区运输class of vehicle maintenance 汽车维护类别class of vehicle repair 汽车修理类别classification 整理classification of standards document. 标准文献分类cleaner 清洗剂cleaning cloth 抹布cleanness 清扫clearance 径向间隙clockwise 顺时针clogged filter 滤清器阻塞close type socket joint 封闭式插接closed chain mechanism 闭链机构closed kinematic chain 闭式链cloud point 浊点club car 高尔夫球车clutch 离合器clutch explosion 离合器炸裂coarse thread 粗牙螺纹coating for protection against corrosion 防腐镀层code fo practice 实施规则coefficient of availability of vehicle 车辆完好率coefficient of friction 摩擦系数coefficient of speed fluctuation 机械运转不均匀系数coefficient of speed fluctuation 速度不均匀( 波动) 系数coefficient of travel speed variation 行程速度变化系数coefficient of utilization of automobile 出车率coefficient of utilization of ton-kilometers 吨公里利用系数coefficient of velocity fluctuation 运转不均匀系数coil stock 卷料coincident points 重合点coining press 精压机coining press 精压机coke-fired furnace 焦碳炉cold brittleness 冷脆性cold draw 冷拉cold drawing low carbon seamless steel tube 冷拔低碳无缝钢管cold drawing spring steel 冷拉弹簧钢cold extruding 冷挤压cold forging 冷锻cold forging die 冷锻模cold pressure welding 冷压焊cold rinse bank 冷水槽cold rolled thin steel sheet 冷轧薄钢板cold rolling killed steel sheet 镇静钢冷轧钢板cold rolling rimmed steel sheet 沸腾钢冷钆钢板cold running-in 冷磨合cold slug 冷块cold treatment 冷处理cold trim 冷切边collapse of piston skirt 活塞裙部挤扁collection of standard decumnets 标准文献收集combination in parallel 并联式组合combination in series 串联式组合combinaton pliers 鲤鱼钳combined efficiency; overall efficiency 总效率combined mechanism 组合机构combined stress 复合应力combusion teste 燃烧分析仪combustion teste 燃烧（废气）分析仪commercial bronze 工业用铜common apex of cone 锥顶common equipment 常用设备common equipment 常用设备common goods 普通货物common normal line 公法线commuter 月票乘客company standard(enterprise standard) 企业标准comparable standard 可比标准compensation 补偿compensation fare 补票complementary standard 补充性标准complete annealing 完全退火complete failure 完全故障complete penetration 焊透complex mechanism 复杂机构complex steel sheet with chromate zinc 铬酸锌复合钢板composite tooth form 组合齿形compound (or combined) gear train 复合轮系compound combining 复合式组合compound die 合模compound flat belt 复合平带compound gear train 混合轮系compound hinge 复合铰链Compound screw mechanism 复式螺旋机构compressed gas 压缩煤气compression strength 抗压强度compressive stress 压应力compresson coil spring 压缩螺旋弹簧compressor 压缩机compressor oil 压缩机机油computer aided design, CAD 计算机辅助设计computer aided manufacturing, CAM 计算机辅助制造computer integrated manufacturing system, CIMS 计算机集成制造系统concave 凸concavity 凹面、凹度Conceal Install 暗装concept design, CD 方案设计、概念设计conclusion 结论concurred design, CD 并行设计concurrent engineering 并行工程condenser tester 电容器试验器condition of self-locking 自锁条件conduction of heat 导热性cone angle 圆锥角cone distance 锥距cone-worm milling machine 球面蜗杆铣床conical roller bearing 圆锥形滚子轴承conical spring 锥形弹簧conjugate cam 共轭凸轮conjugate profiles 共轭齿廓conjugate yoke radial cam 等径凸轮connecting rod alignment fixture 连杆矫正器connecting rod, coupler 连杆connection box 接线盒connection test 检查接线conoid helical-coil compression spring 圆锥螺旋扭转弹簧conservation 清洁constantan 康铜constant-breadth cam 等宽凸轮constant-velocity (or double) universal joint 双万向联轴节constitution of mechanism 机构组成constitution of standard 标准的构成constraining force 约束反力constraint 约束constraint condition 约束条件consumption 消耗contact points 啮合点contact ratio 重合度contact seal 接触式密封contact stress 接触应力container transport 集装箱运输content 目次content of normative document 标准文件的内容continous furnace 连续炉continuous broaching 连续拉削control center 调度中心control panel 控制屏control station 调度站Control switches 控制开关conventional mechanism; mechanism in common use 常用机构convex 凹convex 凸的，凸面体convex roller 球面滚子Conveyer 流水线物料板Conveyer 流水线物料板coolant 冷却液coordinate 座标coordinate frame 坐标系copper 紫铜Copper core power cable 铜芯电力电缆copy grinding mahcine 靠模磨床copy lathe 仿形车床cork 软木correcting plane 平衡平面correcting plane 校正平面corrigenda 勘误表corrosion inhibitor 搞腐蚀剂corrosion resistance 耐腐蚀性corrosion resisting cast iron 耐蚀铸铁corrosion wear 腐蚀性磨损cosine acceleration (or simple harmonic) motion 余弦加速度运动cosmetic defect 外观不良cosmetic inspect 外观检查cosmetic inspect 外观检查cost 成本cost of labor 人工费coulometer 库仑计counter sinking 锪孔counterclockwise (or anticlockwise) 逆时针counterweight 平衡重couple 力偶coupler-curve 连杆曲线coupling shaft coupling 联轴器cover plate 盖板covered arc welding 手工电弧焊covering power 深镀能力crank 曲柄crank angle between extreme (or limiting) positions 极位夹角crank arm, planet carrier 系杆crank press 曲轴压力机crank shaft 曲柄轴crank shaft 曲轴crank shaper (guide-bar) mechanism 曲柄导杆机构crank-rocker mechanism 曲柄摇杆机构cranksahft journal grinding machine 曲轴主轴颈磨床crankshaft (main journal turning lathe) 曲轴（主轴颈）车床crankshaft dynamic balancing machine 曲轴动平衡机crankshaft grinding machine 曲轴磨床crankshaft journal face hardening machine 曲轴轴颈表面淬火机床crankshaft journal milling machine 曲轴轴颈铣削专用机床crankshaft polishing machine 曲轴轴颈抛光机床crankshaft superfinishing machine 曲轴超精磨机床crankshaft turning lathe 曲轴车床creation design 创新设计crepon finish 皱纹漆crimp paper 瓦楞纸critical defect 极严重缺陷critical failure 致命故障critical point 临界点critical speed 临界转速cross grinding 端面磨削cross weld 横向焊缝cross-belt drive 交叉带传动crossed helical gears 交错轴斜齿轮crossover 交叉器cross-shaped joint 十字接头crown gear 冠轮crown shaving 剃鼓形齿crusher 破碎机cryptometer 遮盖力测定仪crystallization point 结晶温度CSBS yearbook 中国标准化年鉴cst bimetal 铸造双金属culture 教养cupola (cupola furnace) 冲天炉curb window 安全监视窗curling 卷边Current by Phase 每相电流current repair of vehicle 汽车小修curvature 曲率curve matching 曲线拼接curved-shoe follower 曲面从动件curve-tooth bevel gear milling 弧齿锥齿轮铣刀盘刃curve-tooth bevel gear milling machine 弧齿锥齿轮铣齿机curvilinear motion 曲线运动cushion 缓冲cut-off (shear-out) 切口cutter 刀具cutter grinding machine 工具磨床cutting machine 切割机cutting-out press 切断压力机cyaniding 氰化cycle 周波cycle of motion 运动周期cycloidal gear 摆线齿轮cycloidal motion 摆线运动规律cycloidal tooth profile 摆线齿形cycloidal-pin wheel 摆线针轮cylinder block broaching machine 气缸体专用拉床cylinder block side broaching machine 气缸体侧拉床cylinder boring machine 镗缸机cylinder compression gauge 气缸压力表cylinder honing machine 气缸珩磨机cylinder leak tester 气缸漏气率检验仪cylinder perpendicularity gauge 气缸孔垂直检验仪cylinder pressure gauge 气缸压力表cylinder score 拉缸cylinder sticking 咬缸cylindric pair 圆柱副cylindrical cam 圆柱凸轮cylindrical coordinate manipulator 圆柱坐标操作器cylindrical grinding 外圆磨削cylindrical roller 圆柱滚子cylindrical roller bearing 圆柱滚子轴承cylindrical worm 圆柱蜗杆cylindroid helical-coil compression spring 圆柱螺旋压缩弹簧cylindroid helical-coil extension spring 圆柱螺旋拉伸弹簧cylindroid helical-coil torsion spring 圆柱螺旋扭转弹簧D.C traction substation 直流牵引变电站D.I. rinse 纯水次daily sevice 每日保养damage 损坏date of standard implementation 标准实施日期dated reference (to standards) 注明日期的引用（标准）day and night line 昼夜线路day and night vehicle 昼夜车dead point 死点deadener 防声胶decantation 沉淀法decelerated run 压点decentralized transportation 分散运输decision items 决议事项decoiling unit 开卷机dedendum 齿根高dedendum circle 齿根圆deemed-to-satisfy provision 认为满足规定deep drawing sheet 深冲压用薄钢板deep drawng 拉伸deep groove ball bearing 深沟球轴承deep hole working 深孔加工deep penetration electrode 深熔焊条deep penetration welding 深溶焊defect 缺陷defective product box 不良品箱defective product label 不良标签defective product label 不良标签defective product/non-good parts 不良品defective products 不良品defective products, not up-to-grade products 不良品defective shock absorber 减震器失效defective to staking 铆合不良defective to staking 铆合不良defective upsiding down 抽芽不良defective upsiding down 抽芽不良defective vacuum advance 真空提前失效deficient manufacturing procedur 制造过程不良deficient purchase&(3640个)attendant seat 乘务员座椅augular offset 角度偏差ausforming 形变热处理austenite 奥氏体authority 权力机构autoclino 自动壳型机automatic box splitter 自动分箱机automatic closer 自动合箱机automatic compensating device for boring cutter wear 镗刀磨损自动补偿装置automatic gas cutting 自动气割automatic headstock changing N/C machine 自动更换主轴箱数控机床automatic inspection machine for piston ring tension 活塞环弹性自动检验机automatic instruction calling device 自动指令呼叫装置automatic line for weighting connecting rod 连杆称重去重自动线automatic moulding productio line ofr cylinder block 缸体自动造型生产线automatic multi-stage cold fromer 多工位自动冷镦机automatic plating machine 自动电镀装置automatic production line for automobile final drive housing 汽车主减速器壳加工自动线automatic production line for connecting rod 连杆加工自动线automatic production line for cranshaft dynamic balance 曲轴动平衡自动线automatic production line for cylinder block 气缸体加工自动线automatic production line for cylinder head 气缸盖加工自动线automatic production line for gas carburization 气体渗碳自动线automatic screwdriver 电动启子automatic sprayer 自动喷漆机automatic ticket checker 自动检票机automatic tool changing N/C machine 自动换刀数控机床automatic welding 自动焊接automation 自动化automobile transportation enterprise 汽车运输企业automotive alcquer 汽车用喷漆automotive enamel 汽车漆automotive topcoat 汽车面漆auxiliary fuction 辅助功能available material 良品可使用average days during major repair of vehicles 汽车大修平均在修车日average days in plant during major of vehicles 汽车大修平均在厂车日average interval mileage of major repair of vehicles 汽车大修间隔里程average main-hours of vehicle maintenance and repair 汽车维修平均工时average stress 平均应力average tonnage (passenger seat) 平均吨（客）位average velocity 平均速度avional 铝合金axial contact bearing 轴向接触轴承axial direction 轴向axial internal clearance 轴向游隙axial load 轴向载荷axial load factor 轴向载荷系数axial plane 轴向平面axial thrust load 轴向分力axial tooth profile 轴向齿廓axle stand 轮轴架babbit metal 巴氏合金back cone 背锥back cone angle 背锥角back cone distance 背锥距back fire 回火back flow 回流backlash 侧隙backlash 齿侧间隙backlash 间隙back-to-back arrangement 背对背安装bad condition of vehicle 汽车不良状况baffle plate 挡块bainite 贝氏体bakelite 胶木（电木）baking paint 烘漆balance 平衡balance of machinery 机械平衡balance of mechanism 机构平衡balance of rotor 转子平衡balance of rotors 回转体平衡balance of shaking force 惯性力平衡balancing centering machine 平衡-钻中心孔机床balancing machine 平衡机balancing mass 平衡质量balancing quality 平衡品质balancing speed 平衡转速balata 巴拉塔树胶balata spring 橡胶弹簧ball 球ball bearing 球轴承ball bearing 球轴承ball screw 滚珠丝杆band brake 带式制动器band-aid 创可贴bar stock cutting by punching 冲压下料barcode 条码barcode scanner 条码扫描器barrel (cylindric) cam 圆柱式凸轮步进运动机构barrel plating 滚镀bar-type cylinder gauge 杆式气缸量规base circle 基圆base cone 基圆锥base cylinder 基圆柱base pitch 基圆齿距basic dynamic axial load rating 轴向基本额定动载荷basic dynamic radial load rating 径向基本额定动载荷basic international standard 基础国际标准basic rating life 基本额定寿命basic standard 基础标准basic static axial load rating 轴向基本额定静载荷basic static radial load tating 径向基本额定静载荷basic terms 基本术语basket 蝴蝶竺batch furnace 分批炉battery hydrometer 蓄电池液体比累计battery welder 蓄电池式焊机be put in storage 入库beacon 警示灯bead 焊道bead cracking 焊道裂纹bead welding 堆焊beading stress 弯曲应力bearing 轴承bearing alloy 轴承合金bearing block 轴承座bearing bore diameter 轴承内径bearing bush 轴瓦、轴承衬bearing cap 轴承盖bearing capacity 承载能力bearing capacity factor 承载量系数bearing clearance 轴承间隙bearing cone 轴承内圈bearing cup 轴承盖bearing cup 轴承外圈bearing height 轴承高度bearing life 轴承寿命bearing metal 轴承合金bearing outside diameter 轴承外径bearing race 轴承座圈bearing ring 轴承套圈bearing saddle 轴承座bearing score 拉瓦bearing shell 轴瓦bearing shim 轴承垫片bearing steel 轴承钢bearing width 轴承宽度beeswax 蜂蜡behind schedule 晚点。

Addendum

1.1 Stresses in the Target. Length of the Target Tooth
The analysis of results obtained by a Monte Carlo simulation of the proton beam transport to the NuMI target using mentioned above input conditions shows that: the proton beam is essentially non-symmetrical in the horizontal plane (X{direction); the beam distribution in the vertical plane (Y{direction) is symmetrical, but non{Gaussian and may be described well by the 8-th order polynomial N (y) = P4=0 k y2k . k Results of stress calculations in the target as functions of the tooth length are shown in Figure 1.1 for graphite target and in Figure 1.2 for beryllium one. As it follows from these Figures: for graphite target the equivalent stress reaches its minimum value of 16.3 MPa at the length of the tooth equal to 6.2 mm; for beryllium target the equivalent stress reaches its minimum value of 117 MPa at the length of the tooth equal to 8 mm.

火山作文英语

Volcanoes are one of the most fascinating and powerful natural phenomena on Earth. They are geological formations that result from the eruption of molten rock,known as magma,from beneath the Earths surface.Here is a detailed exploration of volcanoes in an English essay format:IntroductionA volcano is a vent in the Earths crust through which molten rock,gases,and ash are expelled.They are often associated with the destructive power they can unleash,but they also play a crucial role in the formation of new land and the recycling of the Earths crust.Types of Volcanoes1.Cinder Cone Volcanoes:These are the simplest type of volcano,formed from the accumulation of small,solidified lava fragments that have been ejected from the vent.posite Volcanoes:Also known as stratovolcanoes,they are made up of alternating layers of lava and ash,often with a steep profile and a summit crater.3.Shield Volcanoes:These have a broad,gently sloping profile,resembling a warriors shield.They are formed from the eruption of lowviscosity lava that flows easily.4.Caldera Volcanoes:Formed by the collapse of a volcanic structure following a major eruption,they often have a large,bowlshaped depression.Formation of VolcanoesVolcanoes form at plate boundaries where the Earths crust is either spreading apart or colliding.At divergent boundaries,magma rises to the surface,creating new crust and often shield volcanoes.At convergent boundaries,one plate is forced under another, melting and creating magma that can rise to form composite volcanoes.Eruption ProcessA volcanic eruption begins with seismic activity and ground deformation as magma rises towards the surface.This is often followed by the ejection of gases,ash,and lava.The type of eruption can vary from quiet effusive eruptions to explosive ones,which can cause widespread devastation.Effects of Volcanic Eruptions1.Environmental Impact:Volcanic ash can disrupt air travel,affect climate by reflecting sunlight,and enrich soil with minerals.2.Geological Impact:Lava flows can create new land and reshape existing landscapes.3.Human Impact:While they can cause loss of life and property,they also provide fertile soil for agriculture and geothermal energy resources.Volcano Monitoring and SafetyScientists monitor volcanoes using seismographs,GPS,and satellite imagery to predict eruptions and mitigate risks.Evacuation plans and early warning systems are crucial for communities living near active volcanoes.ConclusionVolcanoes are aweinspiring features of our planet,offering both beauty and danger. Understanding their formation,types,and the processes involved in eruptions is essential for appreciating their role in the Earths geological history and for ensuring the safety of those living in their shadow.。

OTN学习笔记0514

OTN学习笔记OTN基本原理OTN产生背景原有WDM技术仅在物理层面上统一标准，即针对WDM系统中传送信号的波段、频率间隔等做出了规定，对信号的帧结构没有制定统一的标准。

使得WDM在传递如STM64、10GbE等信号时产生了性能监测、帧结构、开销管理等难题。

OTN特点OTN是以波分复用技术为基础，通过G.872、G.709、G.798等一系列ITU-T的建议所规范的新一代“数字传送体系”和“光传送体系”。

OTN解决传统WDM网络无波长/子波长业务调度能力、组网能力弱、保护能力弱等问题。

在OTN网络的边缘层，业务信号被封装进入统一的、开销丰富的OTN体制中的帧结构中去，实现基于OTN体制的WDM全网统一运营、管理、维护。

OTN在电域为OTH，在光域为ROADM。

OTN在光域内可以实现业务信号的传递、复用、路由选择、监控，并保证其性能要求和生存性。

OTN可以支持多种上层业务或协议，如SONET/SDH，ATM，Ethernet，IP，PDH，FibreChannel，GFP，MPLS，OTN虚级联， ODU复用等。

下表为ITU-T构建的OTN协议框架。

OTN基本概念光通路opticalchannel（OCh[r]），OCh是用于支持OCh路径的信息结构，根据是否支持非随路开销（OCh_OH），定义了两种OCh，即支持非随路开销的全功能光通路（OCh）和不支持非随路开销的简化功能光通路（OChr）。

本标准定义的OCh的客户信号为OTUk信号，其它数字客户信号如STM-N、以太网等OTM也可支持。

另外，OCh应具有区分两个不同的OCh信号（一个信号承载OTU1，另一个信号承载OTU2或GbE）的特征，具体实现待研究。

光通路数据单元opticalchanneldataunit（ODUk），ODUk是包括信息净荷（OPUk）和与ODUk开销相关的信息结构。

ODUk的容量由k区分，k＝0，1，2，2e，3，4。

DNA折纸技术

载药新材料研究进展
——DNA折纸技术
2013-11-14
2006年美国加州理工学院计算机生物工程师Paul Rothemund开发了一种“DNA折纸术”（ DNA origami technique），像折叠一条长带子那样，把一条DNA长链反复折叠，形成需要的图形，就像用一根单线条绘制出整幅图画。折叠后的DNA长链，通过一些“钉子”对适当位置上的DNA 短链加以固定，从而构建出了一张二维结构的精美图谱。
Compared to many other nanoscale systems designed for drug delivery such as polymer micelles and inorganic particles, DNA origami based construction has several advantages: (i) same size, shape, and charge for each particle instead of the size distribution often seen for self-assembled nanostructures; (ii) perfect control of the placement of functionalities on the structure using specific oligos.
DNA折纸技术可以将DNA折叠为二维或三维的纳米级形状。这种技术是由美国加州理工学院的Paul Rothemund博士发明的，在诊断设备的新型分子传感器、分子药物容器、药物递送系统的开发，以及确定酶的级联反应中，DNA折纸技术都将具有重要的应用。在许多的实验室中， DNA支架，或者更为精巧的DNA结构正在被用于各种新颖的应用上。

21世纪是生命科学的世纪20世纪后叶分子生物学的突破性...

第一章绪论一简答题1. 21世纪是生命科学的世纪。

20世纪后叶分子生物学的突破性成就，使生命科学在自然科学中的位置起了革命性的变化。

试阐述分子生物学研究领域的三大基本原则，三大支撑学科和研究的三大主要领域？答案：（1）研究领域的三大基本原则：构成生物大分子的单体是相同的；生物遗传信息表达的中心法则相同；生物大分子单体的排列（核苷酸，氨基酸）导致了生物的特异性。

（2）三大支撑学科：细胞学，遗传学和生物化学。

（3）研究的三大主要领域：主要研究生物大分子结构与功能的相互关系，其中包括DNA和蛋白质之间的相互作用；激素和受体之间的相互作用；酶和底物之间的相互作用。

2. 分子生物学的概念是什么？答案：有人把它定义得很广：从分子的形式来研究生物现象的学科。

但是这个定义使分子生物学难以和生物化学区分开来。

另一个定义要严格一些，因此更加有用：从分子水平来研究基因结构和功能。

从分子角度来解释基因的结构和活性是本书的主要内容。

3 二十一世纪生物学的新热点及领域是什么？答案：结构生物学是当前分子生物学中的一个重要前沿学科，它是在分子层次上从结构角度特别是从三维结构的角度来研究和阐明当前生物学中各个前沿领域的重要学科问题，是一个包括生物学、物理学、化学和计算数学等多学科交叉的，以结构（特别是三维结构）测定为手段，以结构与功能关系研究为内容，以阐明生物学功能机制为目的的前沿学科。

这门学科的核心内容是蛋白质及其复合物、组装体和由此形成的细胞各类组分的三维结构、运动和相互作用，以及它们与正常生物学功能和异常病理现象的关系。

分子发育生物学也是当前分子生物学中的一个重要前沿学科。

人类基因组计划，被称为“21世纪生命科学的敲门砖”。

“人类基因组计划”以及“后基因组计划”的全面展开将进入从分子水平阐明生命活动本质的辉煌时代。

目前正迅速发展的生物信息学，被称为“21世纪生命科学迅速发展的推动力”。

尤应指出，建立在生物信息基础上的生物工程制药产业，在21世纪将逐步成为最为重要的新兴产业；从单基因病和多基因病研究现状可以看出，这两种疾病的诊断和治疗在21世纪将取得不同程度的重大进展；遗传信息的进化将成为分子生物学的中心内容”的观点认为，随着人类基因组和许多模式生物基因组序列的测定，通过比较研究，人类将在基因组上读到生物进化的历史，使人类对生物进化的认识从表面深入到本质；研究发育生物学的时机已经成熟。

人与自然篇-备战2023年高考英语时文阅读原创语法填空

高三英语课外时文分类阅读系列(5)第五部分“人与自然”之环境保护篇目录：Passage 1 太空垃圾应该如何清理？Passage 2 保护生物多样性，中国“Z世代”在行Passage 3 中国的“诺亚方舟”Passage 4 太空种菜Passage 5 印度青年用塑料制作运动鞋Passage 6 新版《牛津英语词典》关注气候变化Passage 1主题语境——人与自然——太空垃圾应该如何清理？China deployed a satellite to carry out technological tests for space junk 1.______ (manage). The spacecraft aims to demonstrate technologies to alleviate space debris.Since the dawn of the space age in the 1950s, humans 2. ______ (launch) thousands of rockets and sent even more satellites into orbit. Many are still there, and we are now facing 3. ______ ever-increasing risk of space junk.More than 27,000 pieces of, or “space junk”, are tracked in space. Much more debris is too small to be tracked 4. ______ large enough to threaten human spaceflight and robotic missions. Since a piece of debris can move 5. ______ (fast) than a speeding bullet, collisions with these tiny pieces often leave pits in many satellites, telescopes and other objects orbiting our planet.In 2006, for example, a tiny piece of space junk collided with the International Space Station, 6. ______ (take) a chip out of the heavily reinforced window.Space junk is a huge threat to space missions that involve human life. This is particularly important since careful consideration needs to be made about the orbital path of space junk before spacewalk exercises 7. ______ (conduct).In 2018, the UK’s Surrey Space Center used a net to catch space junk in an experiment. It was the first 8. ______ (success) demonstration of space cleanup technology.Another solution is to use robotic arms. ClearSpace 1, the European Space Agency’s mission 9. ______ (remove) space junk from orbit, is expected to launch in 2025, which will adopt robotic arms to catch the debris. The mission plans to locate, capture and throw debris into the atmosphere, 10. ______ it will burn up in the intense pressure and friction of reentry into the Earth’s atmosphere.【参考答案】1. management2. have launched3.an4. but5. faster6. taking7. are conducted8. successful9. to remove 10. wherePassage 2主题语境——人与自然——保护生物多样性，中国“Z世代”在行动In their spare time, most young people like to enjoy 1. ______ (they) and play on their smartphones. But Li Ruxue is different. He often walks around a forest and isolates himself from the outside world. “Though the lifestyle is a little bit tiring, it’s 2. ______ (meaning),” he often said.In college, Li actively took part in field research. After 3. ______ (graduate), he joined a gibbon protection organization, 4. ______ one of his major responsibilities was picking up gibbon waste. The gibbon is a top-level state-protected animal whose population is smaller than that of wild giant pandas.So over the past four and a half years, Li 5. ______ (follow) gibbons and collected their waste for researchers. Li said the job relies heavily on luck and perseverance. But he has never regretted his choice or felt alone, as he has found more young people 6. ______ (engage) in nature conservation.Like Li, Chu Wenwen, 27, has also worked to protect animals. As her father is engaged in wildlife research, Chu has long been surrounded by wild animals. She fol lowed in her father’s footsteps.Listed 7. ______ a first-class State-protected animal in China, the Mengxin beaver is found only along the Ulungur River in Xinjiang’s Altay prefecture. To protect them, Chu initiated the “beaver canteen” program, which 8. ______ (eventual) attracted over 1 million internet users to donate snack money.According to Fan Pengfei, ecological protection as an industry can provide only a few jobs, most of 9. ______ are in research institutes and nongovernmental organizations. He has seen more and more young people take part-time jobs as journalists, photographers and so on 10. ______ (raise) awareness of wildlife protection. “Young people are the future of the world and the future of global biodiversity conservation,”said Fan.【参考答案】1. themselves2. Meaningful3. graduation4. Where5. has followed6. engaged7. as8. eventually9. which 10. to raisePassage 3主题语境——人与自然——中国的“诺亚方舟”“If the world 1. ______ (end) one day, these collections will bring hope of a new beginning to life on Earth,” said Li Pei, a staff member at the Germplasm Bank of Wild Species, or GBOWS, in Yunnan province.2. ______ (found)in 2007, GBOWS is a research and preservation facility for rare and endangered plants and animals. It is3. ______ (large) in Asia in terms of species.4. ______ number of seed accessions is close to that of the world’s biggest seed bank –the Millennium Seed Bank in the United Kingdom.With two in five plant species at risk of extinction, she said it is a race 5. ______ time to protect the nation’s incredible plant life.So how does the bank work? Scientists collect endangered and useful wild species and send them to the seed bank. For future study, 6. ______ (collect) have to record details of the plant, including 7. ______ it was found, its size and the number of individual plants in the habitat.Once the seeds arrive at GBOWS, they’re dried, preserved in a room and cleaned. After that, X-rays confirm 8. ______ the seeds are undamaged and no insects are hidden inside. The seeds are then frozen, stored in glass bottles and placed in huge freezers at -20 C for long-term storage. Each container has a barcode that can be scanned to enable scientists 9. ______ (view) information about the seeds inside.The bank in Yunnan works with international partners on collecting backup specimens, exchanges and research. It holds 2,176 sets of seeds from 45 countries and regions, with each set 10. ______ (contain) thousands of individual seeds.【参考答案】1. ends2. Founded3. the largest4. The5. against6. collectors7. where8. that9. to view 10. containingPassage 4主题语境——人与自然——太空种菜“Best space tacos yet,” American astronaut Megan wrote on social media Twitter, with a photo of her smiling from ear to ear. The taco feast celebrated the first time peppers were 1. ______ (successful) grown on the International Space Station.Life as an astronaut is 2. ______ (excite), but that doesn’t include food. Astronau ts have endured packaged food for decades. “If you store packaged food for long, the quality, flavor and nutritional quality decrease, the vitamins lessen,” experts said.“3. ______ (grow) colorful vegetables in space can have long-term benefits for physical and psychological health,” said Matt, project scientist at NASA, in 4. ______ statement. The benefits of growing vegetables in space are obvious, but how are they grown?Though astronauts have been growing plants in space for decades, planting edible food without the benefits of gravity and 5. ______ (nature) light has been difficult. A plant growth system called Veggie has been used to grow plants on the space station since 2014. The Veggie garden is about the size of a piece of luggage and typically 6. ______ (hold) six plants. Each plant grows in a “pillow” 7. ______ (fill) with clay and fertilizer. The “pillows” are important for distributing water, nutrients and air in a healthy balance around the roots.8. ______ the absence of gravity, plants use other environmental factors, such as light, to guide growth. LEDs above the plants produce a light suited for the plants’ growth. Veggie typically glows pink, 9. ______ enables plants to use both blue and red wavelengths more efficiently. Other spectrums of light, like greens, yellows or oranges, are less useful for plants.So far, US astronauts 10. ______ (grow) 10 different crops, including lettuce and radish.【参考答案】1. successfully2. exciting3. Growing4. a5. natural6. holds7. filled8. In9. which 10. have grownPassage 5主题语境——人与自然——印度青年用塑料制作运动鞋Fashion designers are always looking for new materials to work with. Lately, it’s all about sustainable materials –1. ______ (recycle) tires, mushrooms, even pineapple fibers! What if you want a sustainable pair of shoes? Thaely is here to help.This sneaker brand out of Dubai wants to fight the growing problem of plastic pollution. 2. ______ (lead) by 23-year-old Indian businessman Ashay Bhave, they may have found a winning strategy: making shoes out of plastic grocery bags. “Thaely” means “plastic bag” in the Hindi language.“I was looking to create footwear that is cost-effective and safe for the environment,” Bhave said in an intervie w. “I needed to come up with something 3. ______ uses recycled plastic without 4. ______ (create) any more plastic waste.”Plastic bags were the perfect solution. Bhave’s home country, India, 5. ______ (ban) single-use plastics. However, in an interview wi th Elle magazine, Bhave said it’s poorly enforced. He said five trillion plastic bags are used around the world each year. “I was motivated to find a solution6. ______ this problem,” Bhave said.That solution was the fabric called ThaelyTex. Made 7. ______ (entire) from plastic bags, the material looks and feels like leather, Bhave claimed. That sounds promising. Better yet, the production process requires no 8. ______ (addition) chemicals and releases no poisonous by-products. The end result is a smart-looking pair of white low-top sneakers.Where do they get so much material? Finally, they got help from TrioTap Technologies, a waste management plant. Bhave said they offered 9. ______ (collect) the bags and also to process them into ThaelyTex.So far, it seems like things are falling into place. There are already hundreds of pre-orders in place. It 10. ______ (sound) s like they have some plans for the future.【参考答案】1. recycled2. Led3. that4. creating5. banned6. to7. entirely8. additional9. to collect 10. soundPassage 6主题语境——人与自然——新版《牛津英语词典》关注气候变化Climate change really does change everything, including language. In October, Oxford English Dictionary (OED) released 1. ____ update on its language on climate change and environmental sustainability.Some new words 2. ______ (include) in the dictionary. T he OED doesn’t include chemical formulas, but it has made an 3. ______( importance) exception for CO2because it has become, in its words, “so ingrained” in our everyday l anguage.“Global heating” is also a new entry. Although people got used to using global warming, OED said that global heating is being used 4. ______ (often). That’s because while global warming suggests a kind of comfort, global heating 5. ______ (convey) “the seriousness of climate change caused by human activity and the urgent need to address it”.Apart from 6. ______( add) these new words, some old words about climate have been given new meanings. The phrase “climate refugee” is an example. In the 19th century, when people spoke of climate refugees, they would be describing those 7. ______ had moved to a place where the climate is healthier.But now, as climate changes and weather events appear 8. ______ (frequent), the phrase refers to the people who are forced to move in response to extreme weather or rising sea levels.Trish Stewart, OED science 9. ______ (edit), said the update reflects the very real sense of urgency of climate change now.10 ______ happens next depends on so many factors but, one thing we can be sure of is that our language will continue to evolve and to tell the story.【参考答案】1. an2. have been included3. important4. more often5. conveys6. adding7. who8. frequently9. editor 10. WhatPassage 7主题语境——人与社会——冬奥黑科技：穿戴技术全面应用From smartwatches that can show and send messages to smart glasses that can 1. _______ (wear)while swimming, wearable devices are playing an important part in making daily life 2. _______ (easy). This technology made its way to the Beijing Winter Games. Let's take a look at some examples.●Wearable thermometric patchesIn light of the recent pandemic, a 3. _______ (health) body is one of the priorities for everyone. 4. _______ (manage) the health status of athletes and audience members for the Beijing Winter Games, a wearable thermometer will be used. The thermometer is 5. _______ the shape of a bandage. It's about 6 centimeters long and 4cm wide. The device features a sensor to detect and record people's temperature. When people wear this “bandage” on their upper arms, their temperatures can be monitored 6. _______ (constant). People can see the data using an app on their phones.●Uniforms and equipmentFor most people, we wear clothes to keep warm or look good. But that's not enough for athletes. Their uniforms and equipment must be functional and not hinder the athlete's high-level performance. To meet these 7. _______ (require), cutting-edge technology has been used.For example, the uniforms use grapheme, a new type of material, which can help absorb athletes' body heat and keep 8. _______ warm for longer. Also, the material is quick-drying, 9. _______ (help) athletes get rid of sweat. The collar of the uniform also features a vent and adjustable buckles to make the clothes breathable.Their shoes use the BOA lacing system, 10. _______ features a button on their shoes. Press it and the shoes fit tighter. This is especially helpful for gloved hands in outdoor settings.【参考答案】1. be worn2. easier3. healthy4. To manage5. in6. constantly7. requirements8. them9. helping 10. which。

沃森和克里克核酸的分子结构--脱氧核糖核酸的结构(1)

沃森和克里克:核酸的分子结构--脱氧核糖核酸的结构
1953年4月25日
我们拟提出脱氧核糖核酸（DNA）盐的一种结构。这种结构的崭新特点具有重要的生物学意义。鲍林和考瑞曾提出过一个核酸结构。他们在发表这一结构之前，欣然将手稿送给我们一阅。他们的模型包含磷酸接近纤维袖，碱基在外周的三条多核苷酸链。我们觉得这样的结构是不够满意的，其理由有二：（1）我们认为进行过X射线衍射分析的样品是DNA的盐而不是游离的酸。没有酸性氢原子，接近轴心并带负电的磷酸会相互排斥。在这样的条件下，究竟是什么力量把这种结构维系在一起，尚不清楚。（2）范德瓦尔力距似显太小。弗雷泽曾提出过另外一种三条多核苷酸链的结构（将出版）。在他的模型中，磷酸在外边，碱基在内部，并由氢键维系着。他描述的这种结构也不够完善，因此，我们将不予评论。我们拟提出一个完全不同的脱氧核糖核酸盐的结构。该结构具有绕同一轴心旋转的两条螺旋链（见图）。根据化学常识我们假定，每条链包括联结β-D-脱氧呋喃核糖的3',5'磷酸二酯键。两条链（不是它们的碱基）与纤维轴旋转对称垂直，并呈右手螺旋。由于旋转对称性，两条链的原子顺序方向相反。每条链都与弗尔伯格的第一号模型粗略地相似；即碱基在螺旋内部，磷酸在外边。糖的构型及其附近的原子与弗尔伯格“标准构型”相似，即糖和与其相联的碱基大致相垂直。每条链在z向每隔3.4埃有一个核苷酸。我们假定，同一条链中相邻核苷酸之间呈36度角，因此，一条链每10个核苷酸，即34埃出现一次螺旋重复。磷原子与纤维轴之间的距离为10埃。因为磷酸基团在螺旋的外部，正离子则易于接近它们。这个结构模型仍然有值得商榷之处，其含水量偏高，在含水量偏低的情况下，碱基倾斜，DNA的结构会更加紧凑些。这个结构的一个新特点就是通过嘌呤和嘧啶碱基将两条链联系在一起。碱基平面与纤维轴垂直。一条链的碱基与另一条链的碱基通过氢键联系起来形成碱基对。两条链肩并肩地沿共同的之向联系在一起。为了形成氢键，碱基对中必须一个是嘌呤，另一个是嘧啶。在碱基上形成氢键的位置为嘌呤的1位对嘧啶的1位；嘌呤的6位对嘧啶的6位。假定核酸结构中碱基仅以通常的互变异构形成（即酮式而非醇式构型）出现，则只能形成专一的碱基对。这些专一碱基对为：腺嘌呤（嘌呤）和胸腺嘧啶（嘧啶），鸟嘌呤（嘌呤）和胞嘧啶（嘧啶）。换言之。按照这种假设，如果一个碱基对中有一个腺嘌呤，在另一条链上则必然是胸腺嘧啶。同样地，一条链上是鸟嘌呤，另一条链上必是胞嘧啶。多核苷酸链的碱基顺序不受任何限制。因此，如果仅仅存在专一碱基对的话，那么，知道了一条链的碱基顺序，则另一条链的碱基顺序自然也就决定了。以前发表的关于脱氧核糖核酸的X射线资料，不足以严格验证我们提出的这种结构。至今，我们只能说它与实验资料粗略地相符合，但在没有用更加精确的结果检验以前，还不能说它已经得到了证明。在本文后面发表的一篇短文提供了一些精确的数据。但是，我们在搞出这个DNA结构以前，并不知道该文报告的详细结果。这个结构模型虽然不是完全地，但主要地是根据已发表的资料和立体化学原则建造起来的。我们当然注意到了，我们提出的专一碱基对直接地表明遗传物质的一种可能的复制机制。该结构的全部细节，包括建造模型的一些条件以及原子的同向性等问题将另行发表。我们非常感谢多纳休经常向我们提出建议和批评，特别是关于原子间距问题。我们也得到伦敦金氏学院威尔金斯博士、富兰克林博士及其同事们一些尚未发表的实验结果和思想的鼓舞。作者之一（沃森）由美国小儿麻痹症国家基金会（Natiortal Foundation for lnfantile Para1ysis，U.S.A。）奖学金资助。剑桥卡文迪什实验室，医学研究委员会生物分子结构研究单位，1953年4月2日。参考文献[1] Pauling，L.，and Corey，R.B.,Nature，171，346 （1953）．Proc.U.S．Nat.Acdd．Sci.，39，84 （1953）.[2] Furberg，S.，Acta.Chem Scand，6，634 （1952）。[3]Chargaff，E., for references see Zamenhof，S.,Brawerman，G.,and Chargaff，E.,Biochim。 Biophys, Acta，9，402 （1952）。[4]Wyatt，G.R.，J.Gen.Physiol，36，201（1952）。[5]〕Astbury，W.T.,Symp. Soc. Exp．BiOl.,l，Nucleic Acid,66（Camb.Univ.press，1947）.[6]Wilkins，M.H.F．，and Randall，T.T.，Biochim，Biophys。 Acta. 10，192（1953）.

昆虫结构英文作文初中

昆虫结构英文作文初中Insects are fascinating creatures with uniquestructures that allow them to survive and thrive in a variety of environments. Their bodies are composed of three distinct segments: the head, thorax, and abdomen. The head contains the eyes, antennae, and mouthparts, while the thorax houses the legs and wings. The abdomen is responsible for digestion and reproduction. These segments are connected by flexible joints that allow insects to move and adapt to their surroundings.One of the most interesting features of insects istheir exoskeleton, a hard outer covering that protectstheir bodies and provides support for their muscles. Unlike the bones of vertebrates, which grow with the animal, the exoskeleton of insects must be shed periodically as the insect grows. This process, known as molting, allows the insect to grow larger and replace any damaged or worn-out parts of its exoskeleton.Insects also have a unique respiratory system that allows them to breathe without lungs. Instead, they have a network of tubes called tracheae that deliver oxygendirectly to their cells. These tubes are connected to tiny openings called spiracles, which are located on the sidesof the insect's body. The spiracles can be opened andclosed to regulate the flow of air and prevent dehydration.Another fascinating aspect of insect structure is their complex eyes. Insects have two types of eyes: compound eyes and simple eyes. Compound eyes are made up of manyindividual lenses, each of which captures a small portionof the insect's visual field. This allows insects to see a wide range of colors and detect movement with incredible speed and accuracy. Simple eyes, on the other hand, areused for sensing light and dark and detecting changes inthe environment.In conclusion, the structure of insects is both diverse and fascinating. From their segmented bodies and exoskeletons to their unique respiratory and visual systems, insects have evolved a variety of adaptations that allowthem to thrive in a wide range of environments. By studying these structures, we can gain a deeper understanding of the complex and diverse world of insects.。

昆虫结构英文作文

昆虫结构英文作文Insects have a diverse range of body structures, from the delicate wings of butterflies to the hard exoskeletonof beetles. These structures are adapted to their specific needs, allowing them to survive and thrive in a widevariety of environments.One of the most fascinating aspects of insect structure is their exoskeleton, which serves as both a protectiveshell and a support for their bodies. This hard outer covering is made of chitin, a tough, flexible substancethat allows insects to move and grow while providing them with a sturdy defense against predators.In addition to their exoskeleton, many insects have specialized structures for feeding and reproduction. For example, bees have pollen baskets on their hind legs tocarry pollen back to the hive, while mosquitoes have a long, piercing mouthpart that allows them to feed on blood.The wings of insects are another remarkable feature of their structure. Some insects, like dragonflies, have large, transparent wings that allow them to maneuver withincredible speed and agility, while others, like beetles, have hardened forewings that protect their delicate hindwings when not in use.Insects also have complex sensory structures, such as compound eyes and antennae, which allow them to detect and respond to their environment. These sensory organs play a crucial role in helping insects find food, communicate with each other, and navigate their surroundings.Overall, the diverse and specialized structures of insects are a testament to their incredible adaptabilityand success as a group. From their exoskeletons to their wings, each feature has evolved to help insects thrive in their unique ecological niches.。

伦敦旅游穿什么英语作文

When planning a trip to London,its important to consider the citys climate and cultural norms when choosing what to wear.Heres a detailed guide to help you pack appropriately for your journey.1.Weather Considerations:London is known for its unpredictable weather,which can vary greatly even within a single day.Its not uncommon to experience rain,so its wise to include the following in your luggage:Raincoat or Waterproof Jacket:A lightweight,packable raincoat is essential.It should be easy to carry around when not in use.Umbrella:A compact,sturdy umbrella is a must to protect against sudden downpours. Layers:Pack layers that can be easily added or removed depending on the temperature.A good base layer might include thermal tops and bottoms.2.Footwear:London is a city best explored on foot,so comfortable and durable shoes are a priority:Walking Shoes:Choose shoes with good support and grip,as youll likely be doing a lot of walking.Comfortable Boots:If youre visiting during the colder months,a pair of waterproof boots is advisable.3.Clothing for Different Seasons:Spring March to May:Light layers are ideal.Include a light jacket or cardigan,along with sweaters that can be worn over tshirts or blouses.Summer June to August:Summer in London can be warm,but its still a good idea to have a light jacket for cooler evenings.Shorts,tshirts,and dresses are suitable for daytime,with a layer for the evenings.Autumn September to November:As the weather cools,add heavier layers such as thicker jackets,scarves,and gloves.Winter December to February:Warm clothing is essential.Include a heavy coat,thermal wear,gloves,a hat,and a scarf.4.Evening Wear:London has a vibrant nightlife,and if you plan on going out,you might want to pack some smartcasual or formal attire:Dress or Smart Casual Outfit:For evenings out,women might consider a nice dress orsmartcasual separates,while men could pack a collared shirt and trousers.Suit or Evening Gown:If youre attending a formal event,a suit and tie for men or an elegant gown for women would be appropriate.5.Cultural Sensitivity:When visiting religious or historical sites,its respectful to dress modestly:Coverups:A scarf or shawl to cover shoulders and knees can be useful when visiting places like churches or museums that may have dress codes.6.Accessories:Dont forget accessories that can add both style and function to your outfits:Hats:Depending on the season,a sun hat or beanie can be both fashionable and practical. Scarves:In addition to their use for modesty,scarves can add a pop of color to an outfit and provide extra warmth.Gloves:For colder months,a pair of gloves can keep your hands warm while allowing you to use your phone or camera.7.Packing Tips:To make the most of your luggage space:Roll Your Clothes:Rolling clothes can save space and reduce wrinkles.Use Packing Cubes:These can help organize your belongings and make it easier to find what you need.Remember,London is a cosmopolitan city with a wide range of dress codes depending on the occasion.Its always better to be prepared for any weather and to respect local customs when dressing for your trip.Happy travels!。

科学性描写去太空的种子会是什么样的作文

科学性描写去太空的种子会是什么样的作文英文版Have you ever wondered what would happen if we were to send seeds into space? Would they grow differently? Would they mutate into new, unknown species? The idea of sending seeds into space for scientific research is not a new one. Scientists have long been curious about how plants would react to the unique conditions of space.One of the main reasons for sending seeds into space is to study the effects of microgravity on plant growth. In space, plants are exposed to microgravity, which means that they are not subjected to the same gravitational force as they are on Earth. This can have a significant impact on how plants grow and develop. Some studies have shown that plants grown in space exhibit different growth patterns, such as increased branching and thicker stems.Another reason for sending seeds into space is to study the effects of cosmic radiation on plant DNA. Cosmic radiation, which consists of high-energy particles from outer space, can cause mutations in plant DNA. By studying how seeds exposed to cosmic radiation develop, scientists can gain a better understanding of how radiation affects plant genetics.Overall, sending seeds into space for scientific research can provide valuable insights into how plants adapt to the unique conditions of space. It can also help scientists develop new strategies for growing food in space, which will be essential for long-term space exploration missions.中文版你是否曾想过如果我们将种子送入太空会发生什么？它们会以不同的方式生长吗？会突变成新的、未知的物种吗？将种子送入太空进行科学研究的想法并不新鲜。

科学进步英语作文初中初三

Science has always been a fascinating subject for me, ever since I was in junior high school. The way it unravels the mysteries of the universe, the intricacies of life, and the subtle workings of nature has always captivated my curiosity. As a junior high school student, I was particularly intrigued by the rapid advancements in science that were transforming the world around us.One of the most significant scientific advancements that I learned about was the discovery of DNA. This was a groundbreaking moment in the field of biology. The double helix structure of DNA, as discovered by Watson and Crick, opened up a whole new world of understanding genetic information. It was fascinating to learn how this tiny molecule could hold the blueprint for all living organisms. The implications of this discovery were enormous, from medical advancements to the understanding of evolution.Another area of science that captured my interest was space exploration. The idea of venturing beyond our planet and exploring the cosmos was thrilling. I remember the excitement of learning about the Apollo missions and the first steps on the moon. The images of Earth from space, the vastness of the universe, and the possibility of life on other planets were topics that sparked my imagination. The recent discoveries of exoplanets and the ongoing Mars exploration missions have only deepened my fascination with space.Technology has also seen tremendous progress during my time in junior high. The advent of the internet and smartphones has revolutionized theway we communicate, access information, and interact with the world. I remember the first time I used a smartphone and the sense of awe at how it could connect me to the entire world with just a few taps on the screen. The internet has become an indispensable tool for learning, with a wealth of information available at our fingertips.In the field of medicine, advancements have been nothing short of miraculous. The development of vaccines has saved countless lives and eradicated diseases that were once widespread. The use of stem cell research has opened up new possibilities for treating various illnesses. As a junior high student, I was amazed by the stories of patients who had been given a new lease on life through medical breakthroughs.Environmental science has also made significant strides, with a growing awareness of the need to protect our planet. The study of climate change and the efforts to develop sustainable energy sources have become increasingly important. As a student, I was inspired by the stories of scientists working to understand and combat these global challenges.In conclusion, the progress of science during my junior high school years has been nothing short of astounding. From the depths of our DNA to the far reaches of space, from the miracles of modern medicine to the challenges of environmental sustainability, science has continued to push the boundaries of our understanding and capabilities. As a junior high student, I was inspired by these advancements and look forward to seeing where the future of science will take us.。

昆虫结构英文作文简单

昆虫结构英文作文简单英文：Insects are fascinating creatures with uniquestructures that allow them to thrive in various environments. From their exoskeletons to their specialized mouthparts, insects have adapted to their surroundings in remarkable ways.One of the most prominent features of insects is their exoskeleton, which is made of chitin and providesprotection and support for their bodies. This hard outer layer also helps prevent water loss, which is essential for insects living in dry environments. Additionally, the exoskeleton allows for muscle attachment, giving insects the ability to move and fly.Insects also have specialized mouthparts that vary depending on their diet. For example, butterflies have a long, coiled proboscis that allows them to reach the nectarof flowers, while mosquitoes have a sharp, piercing proboscis for feeding on blood. Grasshoppers have powerful mandibles that allow them to chew on tough plant material, while bees have a tongue-like structure called a glossathat they use to lap up nectar.Furthermore, insects have compound eyes that allow them to see a wide range of colors and movements. These eyes are made up of thousands of individual lenses, giving insects a panoramic view of their surroundings. Insects also have antennae that are used for sensing their environment, such as detecting pheromones or vibrations.Overall, the unique structures of insects have allowed them to adapt and thrive in various environments, making them a crucial part of many ecosystems.中文：昆虫是一种神奇的生物，其独特的结构使它们能够在各种环境中生存。

2015 BIO Expanded Content Outline

The Biomedicine Expanded Content Outline(Effective as of February 1, 2014)Note to Candidate: This document serves as a guide to assist in examination preparation for candidates who have met NCCAOM eligibility requirements. Below is the content outline for the Biomedicine module, along with the competency statements.Please note: In regards to Clean Needle Technique (CNT), the Biomedicine module focuses on universal precautions and emergency situations in comparison to the Acupuncture with Point Location module which focuses on actual needling and its emergencies (e.g., needle angle and depth).DOMAIN I: Biomedical Model (90% of Total Exam)A. Clinical Application of Biomedical Sciences (including anatomy, physiology, pathology,pathophysiology, etc.), Pharmacology, and Nutrients and Supplements (30%)1. Biomedical sciences∙Differentiate normal and abnormal structures and functions of the body systems from the conventional biomedical perspective∙Recognize signs, symptoms, and morbidities associated with common medical conditions∙Demonstrate knowledge of medical terminology2. Pharmacology∙Recognize functional classifications, mechanisms, side and adverse effects related to commonly used pharmaceuticals (Refer to Appendix A: Pharmaceuticals)∙Recognize routes of administration (e.g., intravenous, oral, subcutaneous)∙Demonstrate knowledge of the effects of the use of tobacco, alcohol, and drugs of abuse∙Recognize common, known pharmaceutical-supplement interactions3. Nutrients and supplements∙Recognize major classifications, known actions, and potential adverse effects related to commonly used nutrients and supplements (Refer to Appendix B: Nutrients andSupplements)∙Recognize signs and symptoms associated with abnormal levels of commonly used nutrients and supplementsB. Patient History and Physical Examination (25%)Understand clinically relevant information gathered through history taking and physicalexamination.Candidates are expected to understand all aspects of the physical examination process.They are not expected to be able to perform all aspects of the physical examinationthemselves.1. Patient history*∙Conduct a medical interview to obtain patient history∙Organize information obtained during interview into appropriate sections of the patient history∙Distinguish the relevant findings obtained during history taking*Patient History includes: chief complaint, history of present illness, allergies, pastmedical history, past surgical history, personal and social history, family history, current medications (prescription and non-prescription), herbs and supplements, review ofsystems2. Physical examination∙Identify the components of the physical examination∙Recognize how each portion of the physical examination is performed∙Distinguish the relevant findings obtained from the physical examinationa. General systems examination (e.g., vital signs, pulmonary, cardiovascular,gastrointestinal, integumentary, etc.)∙Understand relevant examination techniques such as observation, auscultation, and palpation as applied to each system∙Recognize how each portion of the general systems examination is performed∙Distinguish the relevant findings obtained from the general systems examinationb. Musculoskeletal examination∙Understand relevant examination techniques including, but not limited to, range of motion, muscle strength testing, deep tendon reflexes, dermatomal testing,and special tests including orthopedic tests∙Recognize how each portion of the musculoskeletal examination is performed∙Distinguish the relevant findings obtained from the musculoskeletal examinationc. Neurological examination∙Understand relevant examination techniques including, but not limited to, assessment of cognitive function, evaluation of cranial nerves, sensory andmotor function, and reflexes∙Recognize how each portion of the neurological examination is performed∙Distinguish the relevant findings obtained from the neurological examination3. Imaging, laboratory tests, and other medical studiesa. Imaging∙Understand commonly used medical imaging studies (e.g., x-ray, MRI, CT, PET, colonoscopy, cystoscopy, bronchoscopy, etc.)∙Recognize the significance of information gathered from imaging studiesb. Laboratory tests∙Understand commonly used medical laboratory tests** (e.g., complete blood count, basic metabolic panel, urinalysis, liver panel, cardiac panel, thyroid panel,pregnancy test, and reproductive hormones, etc.)**normal ranges will not be tested∙Recognize the significance of information gathered from laboratory testsc. Other medical studies∙Understand other commonly used medical studies (e.g., EMG, EKG, etc.)∙Recognize the significance of information gathered from these studiesC. Clinical Assessment Process (30%)Interpret clinically significant information gathered during history taking and physicalexamination to recognize pathological conditions. (Refer to Appendix C: MedicalConditions)∙Recognize abnormalities in the function of the body systems including, but not limited to, respiratory, cardiovascular, urogenital, reproductive, nervous, integumentary,musculoskeletal, and gastrointestinal systems∙Distinguish between relevant and non-relevant findings∙Recognize typical presentations of commonly encountered medical conditions∙Recognize commonly encountered ominous signs including, but not limited to, medical red flags, mental health red flags, and signs of abuse and traumaD. Clinical Decision-Making and Standard of Care (5%)Analyze information to determine appropriate patient management.∙Recognize medical conditions that may be treated without referral∙Recognize medical conditions that require co-management∙Recognize medical conditions that require a referral∙Differentiate the most appropriate type of referral*** (emergent, urgent, or routine), i.e., the timeframe within which the patient should be seen∙Recognize the conventional biomedical prognoses, management, and/or standard of care for common medical conditions (Refer to Appendix C: Medical Conditions)***emergent (immediate) referral; urgent (24 - 48 hours) referral; routine (48 hours - 7 days) referralDOMAIN II: Office Safety and Professional Responsibilities (10% of Total Exam) Recognize and implement appropriate office safety standards and demonstrate knowledge of professional responsibilities.A. Risk Management and Office Safety∙Recognize situations that require special care or emergency management (e.g., burns, seizures, falls, anaphylaxis)∙Implement emergency office protocols including contacting emergency services as appropriateB. Infection Control∙Identify commonly encountered communicable diseases (e.g., hepatitis, HIV, tuberculosis)∙Identify modes of transmission (e.g., airborne, fecal-oral, vector) and appropriate preventive measurements for common communicable diseases∙Recognize the appropriate office management of commonly encountered communicable diseases and hazardous situations∙Recognize and apply universal precautionsC. Federal Regulations∙Demonstrate knowledge of applicable Occupational Safety and Health Administration (OSHA) and other federal health agencies’ requirements∙Demonstrate knowledge of applicable Health Insurance Portability and Accountability Act (HIPAA) requirementsD. Reporting and Record-Keeping∙Demonstrate knowledge of the required contents and maintenance of medical records ∙Demonstrate knowledge of mandated reportable conditions (e.g., elder and child abuse, infectious diseases, bioterrorism)∙Demonstrate knowledge of the definition and purpose of ICD, CPT, E&M codes∙Demonstrate knowledge of insurance types and requirements (e.g., general liability, malpractice insurance)E. Ethics and Professionalism∙Demonstrate knowledge of NCCAOM® Code of Ethics and other ethical principles (e.g., informed consent, conflict of interest, negligence, boundary violations) ∙Communicate effectively and professionally with patients, the public, and otherhealthcare providersAppendix A: PharmaceuticalsAppendix A is a list of commonly used pharmaceutical categories. The exam will focus on but may not be exclusively limited to the list below.∙allergy/sinus medications∙angina medications∙antiasthmatic medications∙antibacterial medications∙anticancer medications∙anticoagulant medications∙antidepressants∙antidiabetic medications∙antidiarrheal medications∙antifungal medications∙antihyperlipidemic medications∙antihypertension medications∙antinausea medications∙anti-Parkinson medications∙antiprotozoal medications∙antipsychotics∙antiseizure medications∙antiviral medications∙appetite control/weight management medications∙cardiac medications ∙central nervous system (CNS)stimulants/attention deficit medications ∙cough medications∙drugs of abuse∙gastrointestinal medications∙hormonal replacement therapy∙immune modulators∙mood stabilizer medications∙non-steroidal anti-inflammatory drugs (NSAIDs)∙opioids∙osteoporosis medications∙sedatives, anxiolytic and sleepmedications∙sexual dysfunction medications∙smoking cessation medications∙steroids∙stool softeners/laxatives∙thyroid medications∙topical skin medicationsAppendix B: Nutrients and SupplementsAppendix B is a list of commonly used nutrients and supplements. The exam will focus on but may not be exclusively limited to the list below.∙amino acids (e.g., L-glutamine, lysine, choline)∙antioxidants (e.g., coenzyme Q10, selenium)∙bone health (e.g., glucosamine sulfate, chondroitin sulfate)∙digestive support (e.g., enzymes, fiber, probiotics)∙hormones (e.g., melatonin, wild yams, DHEA)∙minerals (e.g., calcium, magnesium, potassium)∙mood support (e.g., St. John's Wort, Sam E, 5 HTP)∙vitamins (e.g., A, B1-B12, C, D, E, K)∙Western herbs (e.g., saw palmetto, milk thistle)Appendix C: Medical ConditionsThe conditions (not system headings) listed below are categorized based on how frequently AOM practitioners reported seeing them in the clinical setting per the 2013 Job Analysis. This list is meant to serve as a study guide for the NCCAOM Biomedicine Examination Module to help prioritize focus of study. The exam will focus on but may not be exclusively limited to the conditions below.The conditions marked with an asterisk (*) signify diseases commonly associated with red flag signs and/or symptoms. Candidates are strongly advised to familiarize themselves with these conditions and the red flag signs and symptoms associated with them.CATEGORY 1 Frequently Seen ConditionsCardiovascular∙*Arrhythmias (e.g., atrial fibrillation, premature ventricular contraction,tachycardia, bradycardia)∙*Blood pressure disorders (hypertension and hypotension)∙Atherosclerosis (e.g., coronary artery disease, peripheral vascular disease)Endocrine and Metabolic conditions∙Thyroid disorders (e.g., Hashimoto’s thyroiditis, Graves’ disease)∙Pancreatic disorders (e.g., diabetes)∙Obesity∙Hyperlipidemia Gastrointestinal conditions∙Gastroesophageal reflux disease∙Gastritis∙Inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis)∙Food sensitivity/allergies (e.g., celiac disease, lactose intolerance)∙Irritable bowel syndromeMental and Behavioral conditions∙*Mood disorders (e.g., depression, bi-polar)∙AnxietyMusculoskeletal conditions∙ Affecting upper extremities (e.g., frozenshoulder, bicipital tendinitis, carpal tunnel syndrome, epicondylitis) ∙ Affecting lower extremities (e.g.,meniscal injuries, compartment syndrome, bursitis)∙ Affecting the axial structures (e.g.,whiplash, disc herniation, spinal stenosis, spondylolisthesis, TMJ) ∙ Osteoarthritis ∙ OsteoporosisNeurological conditions ∙ *Stroke∙ *Radiculopathies (e.g., nerve root,sciatica)∙ Peripheral neuropathy∙ Headache (e.g., cluster, tension,migraine, sinus, trauma)∙ Sleep disorders (narcolepsy, sleepapnea, insomnia)Pulmonary conditions ∙ Asthma∙ Respiratory tract infections (e.g.,sinusitis, viral infections, strep throat, bronchitis, pneumonia) ∙ Allergies ∙ *PneumothoraxReproductive conditions ∙ Menstrual∙ Infertility (e.g., polycystic ovariansyndrome, endometriosis) ∙ MenopauseMiscellaneous∙ Multi-system conditions (Lyme disease,chronic fatigue, fibromyalgia, temporal arteritis)CATEGORY 2 Moderately Seen ConditionsCardiovascular∙*Myocardial infarction∙*Angina pectoris∙*Heart failure∙*Deep vein thrombosis∙Raynaud’s disease∙*AneurysmsDermatological conditions∙Noncontagious skin conditions (cellulitis, shingles, acne, eczema, psoriasis,alopecia)Gastrointestinal conditions∙Peptic ulcer (e.g., H. pylori,Campylobacter)∙*Diverticular disease (e.g., diverticulosis, diverticulitis)∙Hemorrhoids∙Gallbladder conditions (e.g.,cholelithiasis, cholecystitis)Hematological conditions∙Anemia∙Bleeding disordersInfectious Disease∙Sexually transmitted infections∙Tuberculosis ∙*Viral infections (e.g., infectiousmononucleosis, influenza, meningitis,conjunctivitis)Mental and Behavioral conditions∙Attention deficit disorder(ADD)/Attention deficit hyperactivitydisorder (ADHD)∙Post-traumatic stress disorder (PTSD)Neurological conditions∙*Transient ischemic attack (TIA)∙Parkinson’s disease∙*Vertigo∙Bell’s palsy∙Trigeminal neuralgia∙*Concussion and traumatic brain injury (TBI)Pulmonary conditions∙Chronic obstructive pulmonary diseaseReproductive conditions∙Uterine (fibroids and bleeding)Miscellaneous∙Autoimmune disorders [systemic lupus erythematosus (SLE), rheumatoidarthritis (RA)]CATEGORY 3 Least Frequently Seen ConditionsDermatological conditions∙*Contagious skin conditions (lice, fungal infections, scabies)∙*Skin cancers (e.g., basal cell,squamous cell, melanoma)∙BurnsEndocrine and Metabolic conditions∙Adrenal disorders (e.g., Cushing’s, Addison’s)Gastrointestinal conditions∙*Appendicitis∙Hepatitis∙Cirrhosis∙*PancreatitisHematological conditions∙Leukemia/lymphoma∙HemochromatosisInfectious Disease∙*Bacterial infections (e.g., staph, MRSA, impetigo, meningitis)∙Childhood infectious conditions(measles, mumps, rubella, pertussis)∙Parasitic infections∙Foodborne illness Mental and Behavioral conditions∙Autism spectrum∙*Suicidality∙*Eating disorders (anorexia nervosa, bulimia nervosa)Neurological conditions∙Multiple sclerosis (MS)∙Dementia (e.g., Alzheimer’s disease)∙Epilepsy*Oncology (lung, stomach, colon, pancreas, breast, prostate, uterine, bone, liver, cervical)Ophthalmology/ENTReproductive conditions∙*Complications related to pregnancy∙Breast conditions (e.g., mass, mastitis) ∙Male Infertility∙Erectile dysfunction (ED)∙Prostate conditions (benign prostatic hyperplasia, prostatitis)Urinary/Renal conditions∙*Kidney Stones∙*Infections (UTI, cystitis, pyelonephritis) ∙IncontinenceBiomedicine BibliographyThe Content Outline is the primary resource for studying for this examination. The purpose of this Bibliography is only to provide the candidate with suggested resources to utilize in preparation for the examination. Candidates should feel free to consider other resources that cover the material in the Content Outline.There is no single text recommended by NCCAOM. All NCCAOM modules and examinations reflect practice in the United States as determined by the most recent job analysis. NCCAOM’s item writers and examination development committee members frequently use the following texts as resources; however, the sources used are not limited to the books listed here. The NCCAOM® does not endorse any third-party study/preparation guides.Anzaldua, David. An Acupuncturist's Guide to Medical Red Flags & Referrals. Boulder, CO: Blue Poppy Enterprises, Inc., 2010.Bickley, Lynn S. Bates’ Guide to Physical Examination and History Taking. 11th ed.Philadelphia: Lippincott Williams & Wilkins Publishers, 2012.Fischback, Frances and Marshall B. Dunning. A Manual of Laboratory and Diagnostic Tests. 8th ed. Philadelphia: Lippincott Williams & Wilkins Publishers, 2008.Gaby, Alan R. Nutritional Medicine. Concord, NH: Fritz Perlberg Publishing, 2011.Kailin, David C. Quality in Complementary and Alternative Medicine. Corvallis, OR: CMS Press, 2006.Katzung, Bertram G., Susan B. Masters, and Anthony J. Trevor, eds. Basic and Clinical Pharmacology. 12th ed. New York: McGraw Hill Medical, 2011.MacPhee, Stephen J. and Maxine A. Papadakis. Current Diagnosis and Medical Treatment.Columbus: McGraw-Hill Medical. (Current Edition)Magee, David J. Orthopedic Physical Assessment, 5th ed. St. Louis, MO: Saunders Elsevier, 2008.Mahan, L. Kathleen and Sylvia Escott-Stump. Krause's Food & Nutrition Therapy. 12th ed.Philadelphia: Saunders Elsevier, 2008.NCCAOM®. “Code of Ethics.” 2008./wp-content/uploads/pdf/Code%20of%20Ethics.pdf.National Acupuncture Foundation. Clean Needle Technique Manual for Acupuncturists.Guidelines and Standards for a Clean and Safe Clinical Practice of Acupuncture. 6th ed.Chaplin, CT: National Acupuncture Foundation, 2009.PDR Staff (Ed.). PDR for Nonprescription Drugs, Dietary Supplements, and Herbs 2011 (Physicians' Desk Reference for Nonprescription Drugs, Dietary Supplements & Herbs).32nd ed. PDR Network, 2011.Porter, Robert S. (Ed.). The Merck Manual of Diagnosis and Therapy. 19th ed. West Point, PA:Merck & Co. Inc., 2011.。

机械类翻译词汇参考整理

机械类翻译参考词汇表表一3dnow!(3d no waiting)alu(arithmetic logic unit，算术逻辑单元)agu(address generation units，地址产成单元)bga(ball grid array，球状矩阵排列)bht(branch prediction table，分支预测表)bpu(branch processing unit，分支处理单元)brach pediction(分支预测)cmos: complementary metal oxide semiconductor，互补金属氧化物半导体cisc(complex instruction set computing，复杂指令集计算机)clk(clock cycle，时钟周期)cob(cache on board，板上集成缓存)cod(cache on die，芯片内集成缓存)cpga(ceramic pin grid array，陶瓷针型栅格阵列)cpu(center processing unit，中央处理器)data forwarding(数据前送)decode(指令解码)dib(dual independent bus，双独立总线)ec(embedded controller，嵌入式控制器)embedded chips(嵌入式)epic(explicitly parallel instruction code，并行指令代码)fadd(floationg point addition，浮点加)fcpga(flip chip pin grid array，反转芯片针脚栅格阵列)fdiv(floationg point divide，浮点除)femms：fast entry/exit multimedia state，快速进入/退出多媒体状态fft(fast fourier transform，快速热欧姆转换)fid(fid：frequency identify，频率鉴别号码)fifo(first input first output，先入先出队列)flip-chip(芯片反转)flop(floating point operations per second，浮点操作/秒)fmul(floationg point multiplication，浮点乘)fpu(float point unit，浮点运算单元)fsub(floationg point subtraction，浮点减)gvpp(generic visual perception processor，常规视觉处理器)hl-pbga: 表面黏著，高耐热、轻薄型塑胶球状矩阵封装ia(intel architecture，英特尔架构)icu(instruction control unit，指令控制单元)id：identify，鉴别号码idf(intel developer forum，英特尔开发者论坛)ieu(integer execution units，整数执行单元)imm: intel mobile module，英特尔移动模块instructions cache，指令缓存instruction coloring(指令分类)ipc(instructions per clock cycle，指令/时钟周期)isa(instruction set architecture，指令集架构)kni(katmai new instructions，katmai新指令集，即sse)latency(潜伏期)ldt(lightning data transport，闪电数据传输总线)local interconnect(局域互连)mesi(modified，exclusive，shared，invalid：修改、排除、共享、废弃) mmx(multimedia extensions，多媒体扩展指令集)mmu(multimedia unit，多媒体单元)mflops(million floationg point/second，每秒百万个浮点操作)mhz(million hertz，兆赫兹)mp(multi-processing，多重处理器架构)mps(multiprocessor specification，多重处理器规范)msrs(model-specific registers，特别模块寄存器)naoc(no-account overclock，无效超频)ni：non-intel，非英特尔olga(organic land grid array，基板栅格阵列)ooo(out of order，乱序执行)pga: pin-grid array(引脚网格阵列)，耗电大post-riscpr(performance rate，性能比率)psn(processor serial numbers，处理器序列号)pib(processor in a box，盒装处理器)ppga(plastic pin grid array，塑胶针状矩阵封装)pqfp(plastic quad flat package，塑料方块平面封装)raw(read after write，写后读)register contention(抢占寄存器)register pressure(寄存器不足)register renaming(寄存器重命名)remark(芯片频率重标识)resource contention(资源冲突)retirement(指令引退)risc(reduced instruction set computing，精简指令集计算机)sec: single edge connector，单边连接器shallow-trench isolation(浅槽隔离)simd(single instruction multiple data，单指令多数据流)sio2f(fluorided silicon oxide，二氧氟化硅)smi(system management interrupt，系统管理中断)smm(system management mode，系统管理模式)smp(symmetric multi-processing，对称式多重处理架构)soi: silicon-on-insulator，绝缘体硅片sonc(system on a chip，系统集成芯片)spec(system performance evaluation corporation，系统性能评估测试)sqrt(square root calculations，平方根计算)sse(streaming simd extensions，单一指令多数据流扩展)superscalar(超标量体系结构)tcp: tape carrier package(薄膜封装)，发热小throughput(吞吐量)tlb(translate look side buffers，翻译旁视缓冲器)uswc(uncacheabled speculative write combination，无缓冲随机联合写操作)valu(vector arithmetic logic unit，向量算术逻辑单元)vliw(very long instruction word，超长指令字)vpu(vector permutate unit，向量排列单元)vpu(vector processing units，向量处理单元，即处理mmx、sse等simd指令的地方)表二Acetyl||乙酰Acid-proof paint||耐酸涂料, 耐酸油漆Acrylic fiber||丙烯酸纤维Acrylic resin||丙烯酸树脂Active filler||活性填料Adapter assembly||接头组件Addition polyimide||加成型聚酰亚胺Addition polymer||加聚物Adjusting valve||调整阀，调节阀Adhersion assembly||粘合装配Adhersion bond||胶结Adjustable-bed press||工作台可调式压力机Adjuster shim||调整垫片Adjusting accuracy||调整精度，调校精度Admissible error||容许误差Admissible load||容许载荷Adsorbed layer||吸附层Advanced composite material||先进复合材料，高级复合材料Advanced development vehicle||试制车，预研样车AE(Automobile Engineering)||汽车工程技术Aeolotropic material||各向异性材料Aerated plastics||泡沫塑料, 多孔塑料Aerodynamic body||流线型车身Aft cross member||底盘/车架后横梁Air bleeder||排气孔Air clamp||气动夹具Air deflector||导流板;导风板，气流偏转板Air intake manifold||进气歧管Air servo||伺服气泵Air-tight joint||气密接头All-plastic molded||全塑模注的All polyster seat||全聚酯座椅Alligatoring||龟裂，涂膜皱皮,表面裂痕Amino resin||氨基树脂Angular test||挠曲试验Anti-chipping primer||抗破裂底漆(底层涂料)Apron||防护挡板Aramid fibre composites||芳胺纤维复合材料Assembly drawing||装配图Assembly jig||装配夹具Assembly part||装配件，组合件Autoclave forming||热压罐成型Autocorrection||自动校正Automatic compensation||自动补偿Automatic feed||自动进料Automobile instrument||汽车仪表板Automotive transmission||汽车传动装置，汽车变速器Auxiliary fasia console||副仪表板Axial strain||轴向应变Axle bushing||轴衬Axle fairing||底盘车桥整流罩A Stage||A 阶段(某些热固性树脂聚合作用的初期阶段)AAC(Auxiliary Air Control)||辅助空气控制ABC(Active Body Control)||主动式车身控制装置Abherent||阻粘剂Ability meter||测力计，性能测试仪ABL (Ablative)||烧蚀剂Ablation||烧蚀Ablative composite material||烧蚀复合材料Ablative insulative material||烧蚀绝热材料Ablative polymer||烧蚀聚合物Ablative prepreg||烧蚀性预浸料Ablative resistance||耐烧蚀性ABR(Acrylate Butadience Rubber)||丙烯酸丁二烯橡胶Abradant material||研磨材料，磨料Abrade||研磨;用喷砂清理Abrasion||磨耗Abrasion coefficient||磨耗系数Abrasion loss||磨耗量，磨损量Abrasion performance||磨耗性Abrasion-proof material||耐磨材料Abrasion resistant paint||耐磨涂料Abrasion test||磨损试验Abrasive blast system||喷砂清理系统Abrasive cloth||砂布</P< p>表三PCS Pieces 个(根,块等)PRS Pairs 双(对等)CTN Carton 卡通箱PAL Pallet/skid 栈板PO Purchasing Order 采购订单MO Manufacture Order 生产单D/C Date Code 生产日期码ID/C Identification Code (供应商)识别码SWR Special Work Request 特殊工作需求L/N Lot Number 批号P/N Part Number 料号表四A.1. abrasive tooth wear 齿面研磨磨损2. absolute tangential velocity 绝对切向速度3. accelerometer 加速表4. addendum 齿顶高5. addendum angle 齿顶角6. addendum circle 齿顶圆7. addendum surface 上齿面8. adhesive wear 粘着磨损9. adjustability 可调性10. adjustability coefficients 可调系数11. adjusting wedge 圆盘端铣刀的可调型楔块12. allowable stress 允许应力13. alternate blade cutter 双面刀盘14. angular backlash 角侧隙15. angular bevel gears 斜交锥齿轮16. angular displacement 角移位17. angular pitch 齿端距18. angular testing machine 可调角度试验机19. approach action 啮入20. arbor 心轴21. arbor distance 心轴距22. arc of approach 啮入弧23. arc of recess 啮出弧24. attraction 收紧25. average cutter diameter 平均刀尖直径26. axial displacement 轴向位移27. axial factor 轴向系数28. axial locating surface 轴向定位面29. axial pitch 轴向齿距30. axial plane 轴向平面31. axial rakeangle 轴向前角32. axial thrust 轴向推力33. axle testing machine 传动桥试验机B.1. back angle 背锥角2. Back angle distance 背角距(在背锥母线方向)3. Back cone 背锥4. Back cone distance 背锥距5. Back cone element 背锥母线6. Backlash 侧隙7. Backlash tolerance 侧隙公差8. Backlash variation 侧隙变量9. Backlash variation tolerance 侧隙变量公差10. Bandwidth 频带宽11. Base circle 基圆12. Base diameter 基圆直径13. Base pitch 基节14. Base radius 基圆半径15. Base spiral angle 基圆螺旋角16. Basic rack 基本齿条17. Bearing 轴承18. Bearing preload 轴承预负荷19. Bearing spacing/spread 轴承间距20. Bending fatigue 弯曲疲劳21. Bending stress 弯曲应力22. Bevel gears 锥齿轮23. Bias 对角接触24. Bias in 内对角接触25. Bias out 外对角接触26. Blade angle 刀齿齿廓角27. Blade edge radius 刀尖圆角半径28. Blade letter 刀尖凸角代号29. Blade life 刀尖寿命30. Blade point width 刀顶宽31. Blank offset 毛坯偏置距32. Bland position 毛坯位置33. Bottom land 齿槽底面34. Boundary lubrication 界面润滑35. Breakage 破裂36. Bridged contact pattern 桥型接触斑点37. Broach 拉刀38. Burnishing 挤齿C.1. Case crushing 齿面塌陷2. CBN 立方氮化硼3. chamfer 倒角4. chordal addendum 弦齿高5. chordal thickness 弦齿厚6. chuck 卡盘7. circular broach 圆拉刀8. circular face-mill 圆盘端面铣刀9. circular peripheral-mill 圆盘铣刀10. circular pitch 周节11. circular thickness 弧齿厚12. circular thickness factor 弧齿厚系数13. clearance 顶隙14. clearance angle 后角15. coarse pitch 大节距16. coast side 不工作齿侧17. combination 组合18. combined preload 综合预负荷19. complementary crown gears 互补冠状齿轮20. completing cycle 全工序循环21. composite action 双面啮合综合检验误差22. compressive stress 压应力23. concave side 凹面24. concentricity 同心度25. concentricity tester 同心度检查仪26. cone distance 锥距27. cone element 锥面母线28. conformal surfaces 共型表面29. coniskoid 斜锥齿轮30. conjugate gears 共轭齿轮31. conjugate racks 共轭齿条32. contact fatigue 接触疲劳33. contact norma 接触点法线34. contact pattern (tooth contact pattern) 轮齿接触斑点35. contact ratio 重合度36. contact stress 接触应力37. continuous index 连续分度38. control gear 标准齿轮，检验用齿轮39. convex side 凸面40. coolant 冷却液41. corrosive wear 腐蚀性磨损42. corrugated tool 阶梯刨刀43. counter forma surfaces 反法向表面44. cradle 摇台45. cradle test roll 摇台角46. cross 大小端接触47. crossing point 交错点48. crown 齿冠49. crown circle 锥齿轮冠圆50. crowned teeth 鼓形齿51. crown gear 冠轮52. crown to back (轮冠距)轮冠至安装定位面距离53. crown to crossing point 轮冠至相错点距离54. cutter 刀盘55. cutter axial 刀盘的轴向位置56. cutter axial plane 刀盘轴向平面57. cutter axis 刀盘轴线58. cutter diameter 刀盘直径59. cutter edge radius 刀刃圆角半径60. cutter head 刀盘体61. cutter number 刀号62. cutter parallel 刀盘平垫片63. cutter point diameter 刀尖直径64. cutter point radius 刀尖半径65. cutter point width 刀顶距66. cutter spindle 刀盘主轴67. cutter spindle rotation angle 刀盘主轴转角68. cutting distance 切齿安装距69. C.V. testing mashing 常速试验机70. cyclex 格里森粗铣精拉法圆盘端铣刀71. cylindrical gears 圆柱齿轮D.1. Datum tooth 基准齿2. Debur 去毛刺3. Decibel (CB) (噪音)分贝4. Decimal ratio 挂轮比值5. Dedendum 齿根高6. Dendendum angle 齿根角7. Dedendum surface 下齿面8. Deflection 挠曲9. Deflection test 挠曲试验10. Deflection testing machine 挠曲试验机11. Depthwise taper 齿高收缩12. Design data sheet 设计数据表13. Destructive pitting 破坏性点蚀14. Destructive wear 破坏性磨损15. Developed setting 试切调整16. Dial indicator 度盘式指示表17. Diametral pitch 径节18. Diamond 菱形接触19. Dinging ball check 钢球敲击检查20. Disc-mill cuter 盘铣刀21. Dish angle 凹角22. Displacement 位移23. Displacement error 位移误差24. Double index 双分度25. Double roll 双向滚动26. Down roll 向下滚动27. Drive side 工作齿侧28. Duplete 双刃刀29. Duplex 双重双面法30. Duplex helical 双重螺旋法(加工方法之一)31. Duplex spread blade 双重双面刀齿(加工/磨齿方法)32. Duplex taper 双重收缩齿33. Durability factor 耐久系数34. Dynamic factor 动载荷系数E。

关于植树节的英语范文

关于植树节的英语范文1.关于植树节的英语范文篇一Tree Planting Day is coming soon. On this day, everyone goes back to the suburbs and parks to plant trees. At this time, I don't know how to express my feelings.Hundreds of millions of years ago, when the earth was owned by ani mals, plants were luxuriant, full of vitality and green everywhere. Ho wever, after the emergence of human beings with far higher IQ than other animals, plants decreased sharply as if by magic. That is because h umans cut down trees to build houses. Some are due to commercial needs, and a large number of trees have been cut down to leave space for buil ding. Because many people cut down trees and trees without authorizati on, nature is destroyed.There are many disadvantages of cutting down trees. We all know that trees can recycle carbon dioxide. If trees are cut down in large qu antities, the number of trees will decrease sharply, and the carbon di oxide we exhale cannot be recycled. Dense trees can prevent sandstorms. Beijing was hit by sandstorms two years ago, and the whole city was co vered by sand. This is also due to the lack of tree protection.Everyone knows the Central Plains Liangwan City! In the past, there was dilapidated. The tiles of those bungalows were a hole in the east and a hole in the west. The door was made of a piece of wood. The st reets were full of garbage and dirty. Now apartments and buildings have been built in Zhongyuan Liangwan City. The river is clear and the wi llows are swaying gently with the breeze. This is why people realize the importance of respecting nature and protecting the environment.I hope everyone can cherish every flower, grass and tree around hi m.2.关于植树节的英语范文篇二Today is a nice day for going out. Several classmates and I took the bus and came to the southern mountain area of Shuimen Gorge to plant trees. The air here is very fresh, quite different from that in the city. Looking from a distance, the red, green, yellow, purple and vari ous colors of the woods are really like a big colorful garden, which is extremely beautiful!It's time to plant trees! I picked up the bucket and shovel and we nt up the hill with my friends. On the mountain, we each took a peach seedling. Ah! This peach seedling is really long! Stand taller than my father! This peach seedling is really strong! The trunk is as thick as four or five pencils tied together. The root of this peach seedling is really luxuriant! The roots extend in all directions.On the mountain, we found a suitable place to start digging. I als o picked up the shovel and began to dig the hole. My mother said, "Don 't dig the pit too deep or too shallow, so that the peach seedlings ca n't live long. The pit must be dug wide enough to accommodate the root s of the seedlings." After digging, we put the seedlings into the pit, let my mother hold them, and I began to fill. While filling the soil, I poured the water in the bucket into the soil to let the saplings rec eive the moisture of water. After filling the soil, I stepped on the s oft soil with my foot to make it firmer. I wrote down my wish and hung it on the sapling, hoping it would grow up!Next year's Arbor Day, my saplings will grow taller and stronger!3.关于植树节的英语范文篇三March is a good season for planting trees and grass and greening the motherland. Under the guidance of the counselor, the brigade commi ttee of our school went to the suburbs to participate in tree planting activities. On the way, while singing, we enjoyed the beautiful scener y on both sides of the "Outer Ring Road" and were very happy.After a while, the car stopped in front of a wasteland. We got off the bus and arrived at the designated place arranged by the district Y outh League Committee. The counselor assigned us jobs: the senior stud ents were responsible for digging holes, and the middle students were responsible for planting trees. The soil is very soft, but it is still very hard to dig. In a short time, the eldest brother was tired and sw eated. The instructor measured the hole with a ruler and said, "OK! It is completely up to the requirements, and it can be planted." Our tree planting team began to be busy. Liu Ling righted the seedlings, and Gu o Ming used a shovel to spread the soil evenly on them. Wang Na watere d the tree, and Zhao Gang picked up the shovel to reinforce the small tree. People work very hard, for fear that the small trees will fall d own when the wind blows. We planted one tree after another, and plante d one row after another. In a moment, the bare wasteland turned into a small forest.In this tree-planting activity, although we felt a little tired and many students had blisters on their hands, we felt happy to think that we could contribute to the greening of the motherland.4.关于植树节的英语范文篇四In March, light clouds, soft wind and bright sunshine are the best time to plant trees.I made an appointment with my friends to plant trees. Take labor t ools and carry saplings to a desert in the countryside. The monitor gave an order: Everyone should work in groups of two, and each group sho uld be responsible for planting a seedling. Chen Bo and I were in a gr oup. They found a relatively flat place, and you shoveled me to work. Chen Bo is a big man in our class with great strength. He picked up the shovel, aimed at the ground, stepped on the flat place with his foot and pressed it with his hand, and a large piece of soil "bit off". Asfor me, I dig hard with a hoe nearby. We worked hard, and in a moment, a deep tree pit appeared.Looking at the black soil and round pit, Chen Boxi and I smiled. I carried the saplings from the roadside and said to Chen Bo, "Let's invite the saplings into the new house!" Chen Bo nodded, and we both held the saplings upright and gently put them into the pit. I held up the y oung trees, and Chen Bo picked up the shovel and picked up the soil one by one. The tree pit became smaller and smaller, slowly turning into a small mound. Then we went to fetch a bucket of water together, poured it on the root of the tree, and said to the young tree, "Drink, drin k, and grow up quickly when you are full." The young tree swayed gently with the wind, as if to nod to us.Unconsciously, it was evening, and the multicolored rays of the sun were shining on the earth. The saplings were like students in line, doing radio gymnastics. We were tired and sore, panting, but looking at this small sapling and thinking that it would be lush in the near fu ture, the students felt extremely proud.5.关于植树节的英语范文篇五In March, when the sun is clear and the warm wind is blowing, the spring girl quietly comes to the world with light steps. Everything on the earth revived, and the grass drilled out a lovely little head, add ing vitality to the world. The head teacher Wu always led our fifth (5) squadron to plant trees on a small hillside of Feifeng Mountain.We carried the saplings, shovel and buckets to the destination - t he hillside of Feifeng Mountain. The teacher taught us how to plant tr ees and divided us into more than ten groups. Zhao Junjian and I were a group. After a while, everyone found a place to plant trees. Some di g holes, some water, some cultivate soil, and some plant seedlings... We talk and laugh, although sweating, but this is to add a beautiful s cene to the motherland!Zhao Junjian volunteered: "I'm a man. I'll do the heavy work." He had already wielded his shovel. Holding the front end with the left ha nd, and the back end with the hand tightly, push the ground with the b ack foot, lean forward, insert the shovel into the soil, and finally d ig out a piece of soil with great effort. I watched him digging, and I didn't want to fall behind. He picked up the bucket and came to the bo ttom of the clear brook. He squatted down, drew a bucket of water and walked to him, because I usually lack labor, and could not lift a buck et of water. The water in the bucket splashed on the corner of my pant s, but I was not discouraged and didn't care. I went to him. When I ca me to him, he had dug a hole, so I put down the bucket, lifted the sap ling into the soil, held it straight, and he cultivated the soil with a shovel and stepped on it. Finally, I picked up the bucket and watere d it into the gap of the sapling. While watering, I thought: sapling, sapling, you should grow up quickly, add vitality to the earth, add co lor to the motherland!The spring breeze blew gently, as if it blew the small tree open: "Thank you, you have added a beauty to the society, and you have added a green to the earth!" We listened and stood for a long time.。

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a r X i v :m a t h /9903045v 1 [m a t h .A G ] 8 M a r 1999Addendum To:On ﬁbre space structures of a projective irreducible symplectic manifold Daisuke Matsushita E-mail Address tyler@kurims.kyoto-u.ac.jp In this note,we prove that every ﬁbre space of a projective irreducible manifold is a lagrangian ﬁbration.Theorem 1Let X be a projective irreducible symplectic manifold and f :X →B a ﬁbre space with projective base B .Then f is a lagrangian ﬁbration,that is a general ﬁbre of f is a lagrangian submanifold.Remark.Beauville proves that a Lagrangian ﬁbration is a complete integrable system in [2,Proposition 1].Thus,a general ﬁbre of a ﬁbre space of a projective irreducible symplectic manifold is an abelian variety.Remark.Markshevich states in [4,Remark 3.2]that there exists an irreducible symplectic manifold which has a family of non lagrangian tori.But this family does not form ﬁbration.Proof of Theorem.Let ωbe a nondegenerate two form on X and ¯ωa conjugate.Assume that dim X =2n .Then dim F =n [5,Theorem 2],where F is a general ﬁbre
of f .In order to prove that F is a Lagrangian submanifold,it is enough to show
F
ω∧¯ωA n −2=0
where A is an ample divisor on X .Let H ′be an ample divisor on B and H :=f ∗H ′.Then
F
ω∧¯ωA n −2=c (ω¯ωA n −2H n ),
where c is a nonzero constant.We shall show ω¯ωA n −2H n =0.By [3,Theorem 4.7],there exists a bilinear form q X on H 2(X,C )which has the following properties:
a 0q X (D,D )n =D 2n
D ∈H 2(X,C ).
1
We consider the following equation,
a0q X(ω+¯ω+sA+tH,ω+¯ω+sA+tH)n=(ω+¯ω+sA+tH)2n. Calculating the left hand side,we obtain
a0(q X(ω+¯ω)+s2q X(A)+2sq X(ω+¯ω,A)+2tq X(ω+¯ω,H)+2stq X(A,H))n. Sinceω∈H0(X,Ω2X)and A,H∈H1(X,Ω1X),
q X(ω+¯ω,A)=q X(ω+¯ω,H)=0
by[1,Th´e or`e me5].Thus we can conclude thatω¯ωA n−2H n=0by comparing s n−2t n term of both hands sides.Q.E.D.
References
[1]A.Beauville,Vari´e t´e s k¨a hleriennes dont la premi`e re classes de Chern est nulle,J.
Diﬀ.Geom.,18(1983),755–782.
[2]。