化学实验方法外文文献翻译、中英文翻译、外文翻译
非牛顿流体电学：综述外文文献翻译、外文翻译、中英文翻译
附录A 外文翻译译文：非牛顿流体电学：综述3.在非牛顿流体电泳在第二节讨论了关于电渗流带电表面，如果我们通过想象改变参考系统，带电表面的流体应该是静止的，然后将带电面以速度大小相等但与以前面讨论的亥姆霍兹Smoluchowski的速度方向相反移动。
这种情况下有效地代表了电泳具有很薄的EDL的粒子在一个无限大的非运动牛顿流体范围[17,18,26,34] 。
显然，先前讨论电渗的亥姆霍兹Smoluchowski速度当然也可适用于分析在无限大非牛顿流体域具有薄EDL颗粒的电泳速度，仅仅与它的符号相反，并改变了充电通道壁与带电粒子的潜力。
事实上，支付给非牛顿液体粒子电泳最早的关注可以追溯到30年前Somlyody [ 68 ]提起的一项有关采用非牛顿液体以提供优越的阈值特性的电泳显示器的专利。
在1985年， Vidybida和Serikov [ 69 ]提出关于球形颗粒的非牛顿电泳研究第一个理论解决方案。
他们展示了一个粒子在非牛顿净电泳运动流体可通过以交替的电场来诱导一个有趣的且违反直觉的效果。
最近才被Hsu课题组填补这方面20年的研究空白。
在2003年，Lee[70]等人通过一个球形腔的低zeta电位假设封闭andweak施加电场分析了电泳刚性球形颗粒在非牛顿的Carreau流体的运动。
他们特别重视电泳球形粒子位于中心的空腔特征。
之后，该分析被扩展来研究电泳位于内侧的球面的任意位置的球形颗粒的腔体[71] 。
除了单个粒子电泳外， Hsu[72]等人假设粒子分散潜力在卡罗流体zeta进行了集中的电泳调查分析，并分析了由Lee[73]完成的其它任意潜力。
为了研究在边界上非牛顿流体电泳的影响，Lee[74]等人分析了电泳球状粒子在卡罗体液从带电荷到不带电荷的平面表面，发现平面表面的存在增强了剪切变稀效果，对电泳迁移率产生影响。
类似的分析后来由Hsu等 [75]进行了扩展。
为了更紧密地模拟真实的应用环境，Hsu等人[76]分析了球形粒子的电泳由一个圆柱形的微细界卡罗流体低zeta电位到弱外加电场的条件。
scientific method 化学实验
科学方法是一种用于解决问题和回答科学问题的方法。
它是一种系统的方法，可以帮助科学家们确定如何解释自然现象、如何从研究中获取数据以及如何进行实验。
在化学领域，科学方法是进行化学实验的核心。
化学实验是科学研究中非常重要的一部分，它可以帮助科学家们验证他们的假设，并获取关于物质和化学反应的详细信息。
下面简要介绍了在进行化学实验时如何应用科学方法。
1. 提出问题在进行化学实验之前，科学家需要提出一个具体的问题。
这个问题可能是关于化学反应的机制、物质的性质或者化学混合物的成分等等。
这个问题将会成为整个实验的核心和指导。
2. 制定假设在提出了问题之后，科学家需要根据已有的知识和观察到的现象来制定假设。
这个假设是对问题的一个初步猜测，需要能够被实验所验证或者否定。
3. 进行实验在制定了假设之后，科学家会设计并进行实验来验证这个假设。
在进行实验时，需要严格遵守化学实验室的安全规定，使用正确的仪器和试剂，并严密控制实验条件。
4. 观察和记录数据在实验过程中，科学家需要仔细观察实验现象并记录数据。
这些数据应该能够量化和描述实验结果，以便后续的分析和解释。
5. 分析数据并得出结论一旦实验数据收集齐全，科学家需要对数据进行分析，并根据实验结果来验证或者推翻之前的假设。
这个过程可能需要使用统计学方法和化学理论来解释和理解数据。
6. 发表结果科学家会根据实验结果撰写论文或者报告，向其他科学家和学术界公布他们的研究成果。
这些成果可能对化学领域的发展和应用具有重要意义。
科学方法在化学实验中起着非常重要的作用。
它指导着科学家们进行实验研究，在实验中引导科学家们提出假设、收集数据、分析结果，最终推进化学领域的发展。
化学实验不仅依赖科学方法，同时也对科学方法进行了验证和完善，二者相辅相成，共同推动着化学知识的不断进步。
科学方法在化学实验中的应用是化学研究中至关重要的一部分。
通过科学方法，化学家们能够系统地思考问题、收集数据，并得出结论。
英文论文(外文文献)翻译成中文的格式与方法
英文论文（外文文献）翻译成中文的格式与方法英文论文（外文文献）翻译成中文的格式与方法本文关键词：外文，英文，中文，翻译成，文献英文论文（外文文献）翻译成中文的格式与方法本文简介：在撰写毕业设计（论文）或科研论文时，需要参考一些相关外文文献，了解国外的最新研究进展，这就需要我们找到最新最具代表性的外文文献，进行翻译整理，以备论文写作时参考，外文文献中英文文献占绝大多数，因此英文论文准确的翻译成中文就显得尤为重要！一、外文文献从哪里下载1、从知网国际文献总库中找英文论文（外文文献）翻译成中文的格式与方法本文内容：在撰写毕业设计（论文）或科研论文时，需要参考一些相关外文文献，了解国外的最新研究进展，这就需要我们找到最新最具代表性的外文文献，进行翻译整理，以备论文写作时参考，外文文献中英文文献占绝大多数，因此英文论文准确的翻译成中文就显得尤为重要！一、外文文献从哪里下载1、从知网国际文献总库中找，该数据库中包含14,000多家国外出版社的文献，囊括所有专业的英文文献资料。
2、一些免费的外文数据库或网站，为了方便大家查找，编者整理成文档供大家下载：国外免费文献数据库大全下载3、谷歌学术检索工具，检索时设置成只检索英文文献，键入与专业相关的关键词即可检索。
二、英文论文翻译格式与要求翻译的外文文献的字符要求不少于1.5万（或翻译成中文后至少在3000字以上）。
字数达到的文献一篇即可。
翻译的外文文献应主要选自学术期刊、学术会议的文章、有关着作及其他相关材料，应与毕业论文（设计）主题相关，并作为外文参考文献列入毕业论文（设计）的参考文献。
并在每篇中文译文首页用＂脚注＂形式注明原文作者及出处，中文译文后应附外文原文。
需认真研读和查阅术语完成翻译，不得采用翻译软件翻译。
中文译文的编排结构与原文同，撰写格式参照毕业论文的格式要求。
参考文献不必翻译，直接使用原文的（字体，字号，标点符号等与毕业论文中的参考文献要求同），参考文献的序号应标注在译文中相应的地方。
(完整版)化学实验(英文版)
Amidation of Carboxylic Acids:preparation ofAcetanilideChen Xiaoling Class2 2012364217一、 Purpeses and Requirements⑴Learn the principles and operation of aniline aceltylation.⑵Consolidate the recrystallization method and the principle of purflication of organic compounds.二、The experimental princinple and devices.①PrincipleAcetanilide can be prepared from aniline in several ways, using acetyl chloride,acetic anhydride or glacial acetic acid as starting materials. Acetyl chloride reacts very vigorously. Acetican hydride is preferred for a laboratory synthesis because its rate of hydrolysis is low enough to allow the acetylation of amine to be carried out in aqueous solution. It gives a product of high purity and in good yield. The procedure with glacial is of commercial interest since it is economical, but it requires long heating. In the present experiment, we can use either of the following methods to prepare the acetanilide. The main reaction:NH2CH 3COOHNHCOCH3H 2O②DevicesApparatus for preparation of acetanilide 三、Materials and Physical constants四、Procedure五、The result and data analysis①The resultNH2NHCOCH30.055mol0.055molThe theory of produrction:m(Acetanilide)=0.055x135.17=7.4ɡThe actual yield:1.8ɡThe productivity of the Acetanilide:θ=1.8÷7.4×100％=24.3％②Analysis1、Get the 3.2 g of acetanilide and yield is about 63%2、In this reaction, we use excess of acetic acid. On one hand, for low cost and easy to control, on the other hand, the glacial acetic acid is easy to dissolve in the water. So we can separate it from product.3、Zinc powder id added to prevent the aniline from being oxidized during reaction.Do not add too much, otherwise the water-insoluble zinc hydroxide would appear in the procedure of work-up.4、In order to prevent the aniline from being oxidized during the reaction, zinc powder should be added.5、If the solution has color,than add a small amount of activated charcoal,swirl the mixture and allow it to boil gently for a few minutes,and filter out the carbon.6、The product inspection,method are boiling point melting point measure index ofrefraction,besides,you can also use infra tram and hydrogen nuclear magnetic resonance spectra.。
分析化学英文文献（精品资料）
I. vocabularyabsorbance吸光度acetic acid 乙酸acetone 丙酮acetonitrile 乙腈aliquot 等份（试液）aluminum foil 铝箔analytical chemistry 分析化学American Chemical Society (缩写ACS) 美国化学会autosampler 自动进样器beaker 烧杯bibliography 参考书目blender 混合器,搅拌机buffer solution 缓冲溶液burette 滴定管cartridge 柱管centrifugation 离心Chemical Abstracts (缩写CA) 化学文摘chemical analysis 化学分析chromatograph 色谱仪chromatogram色谱图cloud point extraction（缩写CPE）浊点萃取confidence level 置信水平conical flask 锥形瓶daughter ion 子离子dichloromethane 二氯甲烷Diode array detector （缩写DAD）二极管阵列检测器dilution 稀释（n.）disperser solvent 分散剂dispersive liquid–liquidmicroextraction 分散液液微萃取distilled water 蒸馏水dropping pipet 滴管electrochemical analysis电化学分析electrode 电极electrolyte 电解质electromagnetic spectrum 电磁波谱electrospray ionization (缩写ESI ) 电喷雾离子化eliminate 消除（v.）eluate 洗出液eluent 洗脱剂elute 洗脱(v.)elution 洗脱（n.）Encyclopedia of analytical chemistry分析化学百科全书The Engineering Index （缩写EI ）工程索引enrichment factor 富集因子Evaporative Light Scattering Detector(缩写ELSD) 蒸发光散射检测器extract 萃取（v.）、萃取物(n.)extraction efficiency 萃取效率filter 过滤（v.）、过滤器(n.) filtrate 滤出液filtration 过滤fluorescence荧光fluorometry荧光分析法formic acid 甲酸funnel 漏斗gas chromatography–mass spectrometry (缩写GC–MS) 气相色谱-质谱gas chromatography coupled to tandem mass spectrometry （缩写GC–MS/MS）气相色谱-串联质谱gel filtration chromatography凝胶过滤色谱法gel permeation chromatography凝胶渗透色谱法graduated cylinder 量筒high performance liquid chromatography (缩写HPLC) 高效液相色谱homogenate 匀浆(n.) homogenize 使均质，将……打成匀浆hydrophobic 疏水的identification 鉴定Impact Factor影响因子incubation time 温育时间Index to Scientific Technical Proceedings （缩写ISTP）科技会议录索引indicator 指示剂instrumental analysis 仪器分析interference 干扰ion enhancement 离子加强ion exchange chromatography离子交换色谱法ion source 离子源ion suppression 离子抑制limit of detection （缩写LOD）检出限limit of quantitation (缩写LOQ)定量限linearity 线性linear range 线性范围linear regression equation 线性回归方程liquid chromatography tandem massspectrometry （缩写LC-MS/MS）液相色谱串联质谱liquid chromatography withelectrospray ionizationtandem mass spectrometry （缩写LC-ESI-MS/MS）液相色谱电喷雾串联质谱liquid-liquid partition chromatography液液分配色谱法liquid-solid adsorptionchromatography 液固吸附色谱法mass analyzer 质量分析器Mass Spectrometer 质谱仪mass spectrum 质谱图mass-to-charge ratio 质荷比matrix effect 基质效应maximum absorption 最大吸收maximum value 最大值measuring pipet 吸量管methanol 甲醇micelle 胶束microwave assisted extraction 微波辅助提取minimum value 最小值mobile phase 流动相molarity 摩尔浓度monograph专著Multiple-reaction monitoring 多反应监测(缩写MRM)normal phase liquid chromatography正相液相色谱法nominal concentration 标示浓度optimization 优化outlier 离群值parent ion 母离子pipette 移液管polycyclic aromatic hydrocarbons 多环芳烃potentiometry电位法preconcentration 预浓缩primary literature一次文献quadrupole-time- of-flight massspectrometry 四极杆-飞行时间质谱（缩写Q-TOF MS）qualitative analysis 定性分析quality assurance and quality control（缩写QA/QC）质量保证和质量控制quantification 定量quantitative analysis 定量分析reconstitute 重组、复溶（v.）recovery 回收率refractive index detector 折光指数检测器，示差折光检测器relative abundance 相对丰度relative standard deviation （缩写RSD）相对标准偏差reproducibility 重现性reversed phase liquid chromatography（缩写RPLC）反相液相色谱法Royal Society of Chemistry（缩写RSC）英国皇家化学会Science Citation Index （缩写SCI ）科学引文索引Science Citation Index Expanded (缩写SCIE) 科学引文索引扩展版Scientific notation 科学计数法signal to noise ratio （缩写S/N）信噪比size exclusion chromatography尺寸排除色谱法secondary literature二次文献solid-phase extraction （缩写SPE）固相萃取solid-phase microextraction （缩写SPME）固相微萃取spike 添加（v.）standard solution标准溶液stationary phase 固定相stirring bar 搅拌棒stoichiometric point化学计量点surfactant 表面活性剂supernatant 上清液syringe 注射器tap water 自来水Teflon 聚四氟乙烯tetrahydrofuran 四氢呋喃titrant 滴定剂titration滴定Ultra performance liquidchromatography (缩写UPLC) 超高效液相色谱Ultraviolet/VisibleSpectrophotometry 紫外/可见分光光度法vacuum 真空vessel 容器volumetric flask 容量瓶volumetric analysis容量分析法voltammetry 伏安法II. T erms and their definitionsAccuracy 准确度A measure of the agreement between an experimental result and its expected value.Analysis 分析A process that provides chemical or physical information about the constituents in the sample or the sampleitselfAnalyte 被测物，被分析物The constituent of interest in sampleCalibration curve 校准曲线The result of a standardization showing gr aphically how a method’s signal changes with respectto the amount of analyte.Calibration method 校准方法The basis of quantitative analysis: magnitude of measured property is proportional toconcentration of analyteChromophore 生色团A functional group which absorbs a characteristic ultraviolet or visible wavelengthGradient elution 梯度洗脱T he process of changing the mobile phase’s solvent strength to enhance the separation of bothearly and late eluting solutes.Gravimetric analysis重量分析A type of quantitative analysis in which the amount of a species in a material is determined by converting the species into a product that can be isolated and weighed.Isocratic elution 等度洗脱the use of a mobile phase whose composition remains constant throughout theseparation.Matrix 基质All other constituents in a sample except for the analytesMethod blank方法空白A sample that contains all components of the matrix except the analyte.Outlier 离群值Data point whose value is much larger or smaller than the remaining data.Precision精密度An indication of the reproducibility of a measurement or resultQuantitative analysis 定量分析The determination of the amount of a substance or species present in a material. Quantitative transfer 定量转移The process of moving a sample from one container to another in a manner that ensures allmaterial is transferred.Selectivity选择性A measure of a method’s freedom from interferences as defined by the method’s selectivity coefficient. Significant figures有效数字The digits in a measured quantity, including all digits known exactly and one digit (the last) whosequantity is uncertain.Spectrophotometry分光光度法. An analytical method that involves how light interacts with a substanceStock solution储备液A solution of known concentration from which other solutions are prepared.Titration curve滴定曲线A graph showing the progress of a titration as a function of the volume of titrant added.V alidation（方法）确证，验证The process of verifying that a procedure yields acceptable results.Titration error滴定误差The determinate error in a titration due to the difference between the end point and the equivalencepoint.III. Common knowledges1.Some key journals in Analytical Chemistry: Analytical ChemistryTrends in Analytical ChemistryJournal of Chromatography AJournal of Chromatography BAnalystAnalytica Chimica ActaTALANTACritical Reviews in Analytical Chemistry Analytical and Bioanalytical ChemistryELECTROPHORESIS2. T ypes of articles published in scientific journals:Full Length Research PapersRapid CommunicationsReviewsShort CommunicationsDiscussions or Letters to the Editor(Some journals publish all types of articles, while others are devoted to only a single type.)3. The structure of a scientific paper:•Title•Authors (with affiliations and addresses) • Abstract (summary)• Key words•Introduction•Experimental•Results and discussion•Conclusion•Acknowledgement•References4. How to Read a Scientific Paper:Five Helpful Questions•1) WHY did they do this set of experiments?•2) HOW were the experiments actually done?•3) WHA T are the results?•4) WHA T can be concluded from the results?•5) Did they do everything correctly?5. Five-step analyzing process1) Identify and define the problem.2) Design the experimental procedure.3) Conduct an experiment and gather data.4) Analyze the experimental data.5) Report and suggestionIV. T ranslation exercises1. 用分散液- 液微萃取法对杀菌剂的水样品中的测定（杀真菌剂）开发的。
生物科学论文中英文资料外文翻译文献
生物科学论文中英文资料外文翻译文献Carotenoid Biosynthetic Pathway in the Citrus Genus: Number of Copies and Phylogenetic Diversity of Seven GeneThe first objective of this paper was to analyze the potential role of allelic variability of carotenoid biosynthetic genes in the interspecifi diversity in carotenoid composition of Citrus juices. The second objective was to determine the number of copies for each of these genes. Seven carotenoid biosynthetic genes were analyzed using restriction fragment length polymorphism (RFLP) and simple sequence repeats (SSR) markers. RFLP analyses were performed with the genomic DNA obtained from 25 Citrus genotypes using several restriction enzymes. cDNA fragments of Psy, Pds, Zds, Lcyb, Lcy-e, Hy-b, and Zep genes labeled with [R-32P]dCTP were used as probes. For SSR analyses, two primer pairs amplifying two SSR sequences identified from expressed sequence tags (ESTs) of Lcy-b and Hy-b genes were designed. The number of copies of the seven genes ranged from one for Lcy-b to three for Zds. The genetic diversity revealed by RFLP and SSR profiles was in agreement with the genetic diversity obtained from neutral molecμLar markers. Genetic interpretation of RFLP and SSR profiles of four genes (Psy1, Pds1, Lcy-b, and Lcy-e1) enabled us to make inferences on the phylogenetic origin of alleles for the major commercial citrus species. Moreover, the resμLts of our analyses suggest that the allelic diversity observed at the locus of both of lycopene cyclase genes, Lcy-b and Lcy-e1, is associated with interspecific diversity in carotenoid accumμLation in Citrus. The interspecific differences in carotenoid contents previously reported to be associated withother key steps catalyzed by PSY, HY-b, and ZEP were not linked to specific alleles at the corresponding loci.KEYWORDS: Citrus; carotenoids; biosynthetic genes; allelic variability; phylogeny INTRODUCTIONCarotenoids are pigments common to all photosynthetic organisms. In pigment-protein complexes, they act as light sensors for photosynthesis but also prevent photo-oxidat ion induced by too strong light intensities. In horticμLtural crops, they play a major role in fruit, root, or tuber coloration and in nutritional quality. Indeed some of these micronutrients are precursors of vitamin A, an essential component of human and animal diets. Carotenoids may also play a role in chronic disease prevention (such as certain cancers), probably due to their antioxidant properties. The carotenoid biosynthetic pathway is now well established. Carotenoids are synthesized in plastids by nuclear-encoded enzymes. The immediate precursor of carotenoids (and also of gibberellins, plastoquinone, chlorophylls,phylloquinones, and tocopherols) is geranylgeranyl diphosphate (GGPP). In light-grown plants, GGPP is mainly derivedcarotenoid, 15-cis-phytoene. Phytoene undergoes four desaturation reactions catalyzed by two enzymes, phytoene desaturase (PDS) and β-carotene desaturase (ZDS), which convert phytoene into the red-colored poly-cis-lycopene. Recently, Isaacson et al. and Park et al. isolated from tomato and Arabidopsis thaliana, respectively, the genes that encode the carotenoid isomerase (CRTISO) which, in turn, catalyzes the isomerization of poly-cis-carotenoids into all-trans-carotenoids. CRTISO acts on prolycopene to form all-trans lycopene, which undergoes cyclization reactions. Cyclization of lycopene is abranching point: one branch leads to β-carotene (β, β-carotene) and the other toα-carotene (β, ε-carotene). Lycopene β-cyclase (LCY-b) then converts lycopene intoβ-carotene in two steps, whereas the formation of α-carotene requires the action of two enzymes, lycopene ε- cyclase (LCY-e) and lycopene β-cyclase (LCY-b). α- carotene is converted into lutein by hydroxylations catalyzed by ε-carotene hydroxylase (HY-e) andβ-carotene hydroxylase (HY-b). Other xanthophylls are produced fromβ-carotene with hydroxylation reactions catalyzed by HY-b and epoxydation catalyzed by zeaxanthin epoxidase (ZEP). Most of the carotenoid biosynthetic genes have been cloned and sequenced in Citrus varieties . However, our knowledge of the complex regμLation of carotenoid biosynthesis in Citrus fruit is still limited. We need further information on the number of copies of these genes and on their allelic diversity in Citrus because these can influence carotenoid composition within the Citrus genus.Citrus fruit are among the richest sources of carotenoids. The fruit generally display a complex carotenoid structure, and 115 different carotenoids have been identified in Citrus fruit. The carotenoid richness of Citrus flesh depends on environmental conditions, particμLarly on growing conditions and on geogr aphical origin . However the main factor influencing variability of caro tenoid quality in juice has been shown to be genetic diversity. Kato et al. showed that mandarin and orange juices accumμLated high levels of β-cryptoxanthin and violaxanthin, respectively, whereas mature lemon accumμLated extremely low levels of carotenoids. Goodner et al. demonstrated that mandarins, oranges, and their hybrids coμLd be clearly distinguished by theirβ-cryptoxanthin contents. Juices of red grapefruit contained two major carotenoids: lycopene and β-carotene. More recently, we conducted a broad study on the organization of the variability of carotenoid contents in different cμLtivated Citrus species in relation with the biosynthetic pathway . Qualitative analysis of presence or absence of the different compounds revealed three main clusters: (1) mandarins, sweet oranges, and sour oranges;(2) citrons, lemons, and limes; (3) pummelos and grapefruit. Our study also enabled identification of key steps in the diversification of the carotenoid profile. Synthesis of phytoene appeared as a limiti ng step for acid Citrus, while formation of β-carotene and R-carotene from lycopene were dramatically limited in cluster 3 (pummelos and grapefruit). Only varieties in cluster 1 were able to produce violaxanthin. In the same study , we concluded that there was a very strong correlation between the classification of Citrus species based on the presence or absence of carotenoids (below,this classification is also referred to as the organization of carotenoid diversity) and genetic diversity evaluated with bi ochemical or molecμLar markers such as isozymes or randomLy amplified polymorphic DNA (RAPD). We also concluded that, at the interspecific level, the organization of the diversity of carotenoid composition was linked to the global evolution process of cμLt ivated Citrus rather than to more recent mutation events or human selection processes. Indeed, at interspecific level, a correlation between phenotypic variability and genetic diversity is common and is generally associated with generalized gametic is common and is generally associated with generalized gametic disequilibrium resμLting from the history of cμLtivated Citrus. Thus from numerical taxonomy based on morphologicaltraits or from analysis of molecμLar markers , all authors agreed on the existence o f three basic taxa (C. reticμLata, mandarins; C. medica, citrons; and C. maxima, pummelos) whose differentiation was the resμLt of allopatric evolution. All other cμLtivated Citrus specie s (C. sinensis, sweet oranges; C. aurantium, sour oranges;C. paradi si, grapefruit; and C. limon, lemons) resμLted from hybridization events within this basic pool except for C. aurantifolia, which may be a hybrid between C. medica and C. micrantha .Our p revious resμLts and data on Citrus evolution lead us to propose the hypothesis that the allelic variability supporting the organization of carotenoid diversity at interspecific level preceded events that resμLted in the creation of secondary species. Such molecμLar variability may have two different effects: on the one hand, non-silent substitutions in coding region affect the specific activity of corresponding enzymes of the biosynthetic pathway, and on the other hand, variations in untranslated regions affect transcriptional or post-transcriptional mechanisms.There is no available data on the allelic diversity of Citrus genes of the carotenoid biosynthetic pathway. The objective of this paper was to test the hypothesis that allelic variability of these genes partially determines phenotypic variability at the interspecific level. For this purpose, we analyzed the RFLPs around seven genes of the biosynthetic pathway of carotenoids (Psy, Pds, Zds, Lcy-b, Lcy-e, Hy-b, Zep) and the polymorphism of two SSR sequences found in Lcy-b and Hy-b genes in a representative set of varieties of the Citrus genus already analyzed for carotenoid constitution. Our study aimed to answer the following questions: (a) are those genes mono- or mμLtilocus, (b) is the polymorphism revealed by RFLP and SSR markers inagreement with the general histor y of cμLtivated Citrus thus permitting inferences about the phylogenetic origin of genes of the secondary species, and (c) is this polymorphism associated with phenotypic (carotenoid compound) variations.RESΜLTS AND DISCUSSIONGlobal Diversity of the Genotype Sample Observed by RFLP Analysis. RFLP analyses were performed using probes defined from expressed sequences of seven major genes of the carotenoid biosynthetic pathway . One or two restriction enzymes were used for each gene. None of these enzymes cut the cDNA probe sequence except HindIII for the Lcy-e gene. Intronic sequences and restriction sites on genomic sequences werescreened with PCR amplification using genomic DNA as template and with digestion of PCR products. The resμLts indicated the absence of an intronic sequence for Psy and Lcy-b fragments. The absence of intron in these two fragments was checked by cloning and sequencing corresponding genomic sequences (data not shown). Conversely, we found introns in Pds, Zds, Hy-b, Zep, and Lcy-e genomic sequences corresponding to RFLP probes. EcoRV did not cut the genomic sequences of Pds, Zds, Hy-b, Zep, and Lcy-e. In the same way, no BamHI restriction site was found in the genomic sequences of Pds, Zds, and Hy-b. Data relative to the diversity observed for the different genes are presented in Table 4. A total of 58 fragments were identified, six of them being monomorphic (present in all individuals). In the limited sample of the three basic taxa, only eight bands out of 58 coμLd not be observed. In the basic taxa, the mean number of bands per genotype observed was 24.7, 24.7, and 17 for C. reticμLata, C. maxima, and C. medica, respectively. It varies from28 (C. limettioides) to 36 (C. aurantium) for the secondary species. The mean number of RFLP bands per individual was lower for basic taxa than for the group of secondary species. This resμLt indicates that secondary species are much more heterozygous than the basic ones for these genes, which is logical if we assume that the secondary species arise from hybridizations between the three basic taxa. Moreover C. medica appears to be the least heterozygous taxon for RFLP around the genes of the carotenoid biosynthetic pathway, as already shown with isozymes, RAPD, and SSR markers.The two lemons were close to the acid Citrus cluster and the three sour oranges close to the mandarins/sweet oranges cluster. This organization of genetic diversity based on the RFLP profiles obtained with seven genes of the carotenoid pathway is very similar to that previously obtained with neutral molecμLar markers such as genomic SSR as well as the organization obtained with qualitative carotenoid compositions. All these resμLts suggest that the observed RFLP and SSR fragments are good phylogenetic markers. It seems consistent with our basic hypothesis that major differentiation in the genes involved in the carotenoid biosynthetic pathway preceded the creation of the secondary hybrid species and thus that the allelic structure of these hybrid species can be reconstructed from alleles observed in the three basic taxa.Gene by Gene Analysis: The Psy Gene. For the Psy probe combined with EcoRV or BamHI restriction enzymes, five bands were identified for the two enzymes, and two to three bands were observed for each genotype. One of these bands was present in all individuals. There was no restriction site in the probe sequence. These resμLts lead us to believe that Psy is present at two loci,one where no polymorphism was found with the restriction enzymes used, and one that displayed polymorphism. The number of different profiles observed was six and four with EcoRV and BamHI, respectively, for a total of 10 different profiles among the 25 individuals .Two Psy genes have also been found in tomato, tobacco, maize, and rice . Conversely, only one Psy gene has been found in Arabidopsis thaliana and in pepper (Capsicum annuum), which also accumμLates carotenoids in fruit. According to Bartley and Scolnik, Psy1 was expressed in tomato fruit chromoplasts, while Psy2 was specific to leaf tissue. In the same way, in Poaceae (maize, rice), Gallagher et al. found that Psy gene was duplicated and that Psy1 and notPsy2 transcripts in endosperm correlated with endosperm carotenoid accumμLation. These resμLts underline the role of gene duplication and the importance of tissue-specific phytoene synthase in the regμLation of carotenoid accumμLation.All the polymorphic bands were present in the sample of the basic taxon genomes. Assuming the hypothesis that all these bands describe the polymorphism at the same locus for the Psy gene, we can conclude that we found allelic differentiation between the three basic taxa with three alleles for C. reticμLata, four for C. maxima, and one for C. medica.The alleles observed for the basic taxa then enabled us to determine the genotypes of all the other species. The presumed genotypes for the Psy polymorphic locus are given in Table 7. Sweet oranges and grapefruit were heterozygous with one mandarin and one pummelo allele. Sour oranges were heterozygous; they shared the same mandarin allele with sweet oranges but had a different pummelo allele. Clementine was heterozygous with two mandarin alleles; one shared with sweetoranges and one with “Willow leaf” mandarin. “Meyer” lemon was heterozygous, with the mandarin allele also found in sweet oranges, and the citron allele. “Eureka”lemon was also heterozygous with the same pummelo allele as sour oranges and the citron allele. The other acid Citrus were homozygous for the citron allele.The Pds Gen. For the Pds probe combined with EcoRV, six different fragments were observed. One was common to all individuals. The number of fragments per individual was two or three. ResμLts for Pds led us to believe that this gene is present at two loci, one where no polymorphism was found with EcoRV restriction, and one displaying polymorphism. Conversely, studies on Arabidopsis, tomato, maize, and rice showed that Pds was a single copy gene. However, a previous study on Citrus suggests that Pds is present as a low-copy gene family in the Citrus genome, which is in agreement with our findings.The Zds Gene. The Zds profiles were complex. Nine and five fragments were observed with EcoRV and BamHI restriction, respectively. For both enzymes, one fragment was common to all individuals. The number of fragments per individual ranged from two to six for EcoRV and three to five for BamHI. There was no restriction site in the probe sequence. It can be assumed that several copies (at least three) of the Zds gene are present in the Citrus genome with polymorphism for at least two of them. In Arabidopsis, maize, and rice, like Pds, Zds was a single-copy gene .In these conditions and in the absence of analysis of controlled progenies, we are unable to conduct genetic analysis of profiles. However it appears that some bands differentiated the basic taxa: one for mandarins, one for pummelos, and one for citrons with EcoRV restriction and one for pummelos and onefor citrons with BamHI restriction. Two bands out of the nine obtained with EcoRV were not observed in the samples of basic taxa. One was rare and only observed in “Rangpur” lime. The other was found in sour oranges, “V olkamer” lemon,and “Palestine sweet” lime suggesting a common ancestor for these three genotypes.This is in agreement with the assumption of Nicolosi et al. that “V olkamer” lemon resμLts from a complex hybrid combination with C. aurantium as one parent. It will be necessary to extend the analysis of the basic taxa to conclude whether these specific bands are present in the diversity of these taxa or resμLt from mutations after the formation of the secondary species.The Lcy-b Gene with RFLP Analysis.After restriction with EcoRV and hybridization with the Lcy-b probe, we obtained simple profiles with a total of four fragments. One to two fragments were observed for each individual, and seven profiles were differentiated among the 25 genotypes. These resμLts provide evidence that Lcy-b is present at a single locus in the haploid Citrus genome. Two lycopene β-cyclases encoded by two genes have been identified in tomato. The B gene encoded a novel type of lycopene β-cyclase whose sequence was similar to capsanthin-capsorubin synthase. The B gene expressed at a high level in βmutants was responsible for strong accumμLation ofβ-carotene in fruit, while in wild-type tomatoes, B was expressed at a low level.The Lcy-b Gene with SSR Analysis. Four bands were detected at locus 1210 (Lcy-b gene). One or two bands were detected per variety confirming that this gene is mono locus. Six different profiles were observed among the 25 genotypes. As with RFLPanalysis, no intrataxon molecμLar polymorphism was found within C. Paradisi, C. Sinensis, and C. Aurantium.Taken together, the information obtained from RFLP and SSR analyses enabled us to identify a complete differentiation among the three basic taxon samples. Each of these taxons displayed two alleles for the analyzed sample. An additional allele was identified for “Mexican” l ime. The profiles for all secondary species can be reconstructed from these alleles. Deduced genetic structure is given in. Sweet oranges and clementine were heterozygous with one mandarin and one pummelo allele. Sour oranges were also heterozygous sharing the same mandarin allele as sweet oranges but with another pummelo allele. Grapefruit were heterozygous with two pummelo alleles. All the acid secondary species were heterozygous, having one allele from citrons and the other one from mandarins except for “Mexican” lime, which had a specific allele.柑桔属类胡萝卜素生物合成途径中七个基因拷贝数目及遗传多样性的分析摘要：本文的首要目标是分析类胡萝卜素生物合成相关等位基因在发生变异柑橘属类胡萝卜素组分种间差异的潜在作用；第二个目标是确定这些基因的拷贝数。
英文版的化学实验报告
英文版的化学实验报告英文版的化学实验报告Introduction:Chemical experiments are an essential part of scientific research and education. They provide valuable insights into various chemical reactions and help us understand the properties and behavior of different substances. In this report, we will discuss the process and findings of a chemical experiment conducted to investigate the reaction between hydrochloric acid and sodium hydroxide. Experimental Procedure:1. Materials: The materials used in the experiment included hydrochloric acid (HCl), sodium hydroxide (NaOH), distilled water, a burette, a conical flask, a pH meter, and a magnetic stirrer.2. Preparation: A solution of hydrochloric acid was prepared by diluting a given volume of concentrated hydrochloric acid with distilled water. Similarly, a sodium hydroxide solution was prepared by dissolving a specific amount of sodium hydroxide pellets in distilled water.3. Setup: The burette was filled with the sodium hydroxide solution, and the conical flask was placed on the magnetic stirrer. The pH meter was calibrated according to the manufacturer's instructions.4. Titration: The hydrochloric acid solution was slowly added to the conical flask while stirring continuously. The pH meter was used to monitor the change in pH during the titration process. The addition of hydrochloric acid was stopped whenthe pH reached neutrality, indicating that the reaction was complete.Results and Analysis:During the titration process, the pH of the solution gradually decreased as hydrochloric acid was added. Initially, the pH was high, indicating an alkaline solution due to the presence of sodium hydroxide. As the acid was added, the pH decreased until it reached neutrality at a pH of 7. This indicated that the reaction between hydrochloric acid and sodium hydroxide resulted in the formation of water and a salt, which did not affect the pH of the solution.The volume of hydrochloric acid required to reach neutrality was recorded, and the concentration of the sodium hydroxide solution was calculated using the equation:M1V1 = M2V2Where M1 is the concentration of hydrochloric acid, V1 is the volume used, M2 is the concentration of sodium hydroxide, and V2 is the volume of sodium hydroxide used.Discussion:The experiment demonstrated the concept of neutralization, where an acid and a base react to form a salt and water. The reaction between hydrochloric acid and sodium hydroxide is a classic example of neutralization and is widely used in various industries and laboratory settings.The accuracy of the experiment depends on several factors, such as the precision of measurements, the purity of chemicals used, and the propercalibration of instruments. Any deviation in these factors can lead to inaccurate results and affect the overall conclusions drawn from the experiment. Conclusion:In conclusion, the experiment successfully demonstrated the reaction between hydrochloric acid and sodium hydroxide, resulting in the formation of water and a salt. The process of titration allowed us to determine the concentration of the sodium hydroxide solution. This experiment highlights the importance of chemical experiments in understanding the behavior of substances and their reactions. By conducting such experiments, scientists and researchers can gain valuable insights into the world of chemistry and its applications in various fields.。
化学毕业论文英文献及翻译
化学毕业论文英文献及翻译负载水杨醛1,3丙二酸二异丙酯二亚胺(BSPDI)的活性炭分离富集食物样品中某些重金属——火焰原子吸收光谱法测定摘要:在已有的报导中有一种灵敏而又简单的方法，能同时富集实际样品3+3+2+2+2+2+中的Cr、Fe、Cu、Ni、Co和Zn。
在该方法的基础上，将BSPDI 负载-1-1到活性炭上，再用8ml 2mol.L的硝酸的丙酮溶液或10ml 4mol.L的硝酸溶液对改性的活性炭洗提后吸附金属。
经调查分析，包括采样体积和PH值都是影响结果的分析参数。
检测分析物的残留物上的基质离子的影响，通常分析物的回收率是能测定的。
该方法已成功地应用于对一些食物样品中某些金属的内容评价。
1、介绍在包括自然水域的环境样品中，对微量金属的测定是为了表明生态污染程度和有关健康问题。
通常先确定所分离的元素是样品的主要组成部分，而后才涉及到时对这些微量组成的分离富集。
对微量金属的分析存在于各种样品中，像自然界的废水，泥沙和一些分析技术能直接测定的组织。
比如由于其他离子的基质影响、样品中金属离子的浓度转低和选择性低灵敏性低的分析技术而使原子吸收方法就不能用来真接测定。
事实上，固相萃取是一个强大的工具，能分离富集各种无机有机分析物。
在技术上它有风几个优点:固相稳定性好，可重复性好，能达到较高的富集效果，分离富集的动力条件温和，无需特殊的有机溶剂，试剂消耗低产生费用小。
几个选择性的用物理负载或化学绑定的鳌合剂等不同载体的固相萃取物已经准备好，例如:硅胶，活性炭，涂SDS氧化铝，改性硅藻土载体，标记离子聚合物，XAD-2000安伯来树脂。
活性炭是一种广泛应用在水、高纯度物质、蔬菜样品等分析物的多元微量富集的收集物。
一般使用活性炭对金属富集的方法是通过简单调整水溶液的PH到适当的值后与金属进行螯合，此过程的缺点是它需要一系列的络合步骤，因此，最近提出使用螯合活性炭。
金属螯合物可以提供高选择性和高富集效果，寻找这样一种分离富集技术。
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实验方法辐射黑色体理论（Chao et al., 1961）和切削表面理论（Friedman and Lenz, 1970）。
随着敏感的红外感光胶片的发展，在一个可被记录切削侧面温度场的工具（Boothroyd, 1961）和电视型红外线敏感的视频设备已被哈里斯等人使用（1980年），以热传感和半导体量子吸收的原则为基础的红外线传感器的不断发展，使得这些传感器的第二敏感性大于第一次，其时间常数很小太- 在微秒到毫秒的范围之内。
图5.21显示了最新使用的第二类的例子。
有两个传感器以及开始投入使用，一个是在1毫米至5毫米的波长范围的敏感型锑化铟，另外一个是从6毫米至13毫米的敏感型碲镉汞类型，通过与两个不同的探测器信号比较可以使用温度测量更敏感的方法。
大部分金属切削温度已进行了调查和了解使得更好地了解这个过程。
原则上，温度测量可能用于条件监测，例如，警告说如果是天气太热导致切割刀具后刀面磨损，然而，尤其是辐射能尺寸，在生产条件，校准问题以及确保辐射能量途径从伤口区到探测器不被打断的困难，使得以温度测量为目的方法不够可靠切削的另一种方式是监测声发射，这虽然是一个间接的方法，但研究过程的状态是一个值得考虑未来。
5.4 声发射材料的活跃形变—例如裂缝的增长，变形夹杂物，快速塑性剪切，甚至晶界，位错运动都是伴随着弹性应力波的排放而产生。
这就是声发射（AE）。
排放的发生在一个很宽的频率范围内，但通常是从10万赫到1兆赫。
虽然波幅度很小，但是他们可以被检测到，通过强烈的压电材料如钛酸钡或压电陶瓷传感器制造从，（Pb（Zr x Ti1–x）O3; x = 0.5 to 0.6）。
图5.22显示了传感器的结构。
声波传送到压力传感器造成直接的压力E（△L/L），其中E是传感器的杨氏模量，L 是它的长度，△L是它的长度变化。
应力产生电场T = g33E(△L/L)（5.7a）g33是传感器材料的压电应力系数。
传感器两端的电压是TL，然后V= g33E△L（5.7b）g33和E的典型值分别是24.4 × 10-3Vm/ N和58.5GPa，以检测电压高达0.01毫伏，这是可能的。
将这些值代入方程（5.7b）导致了检测△L的长度变化的可以小到7 × 10-15米：对于一个L = 10毫米的传感器来说，即相当于拥有7 ×10-13图5.22显示的是声发射传感器的结构实验理论方法的最小应变，使用应变传感要比使用钢丝应变计更敏感，敏感的最低检测应变约为10-6。
一个AE传感器电信号处理可分为两个阶段。
第一个是通过使用一个低噪声前置放大器和一个带通滤波器（≈100千赫到1兆赫）。
由此产生的信号通常具有的基础上的复杂形式，如图5.23所示，在处理的第二阶段，提取信号的主要特征，例如事件的数量，电压超过某一阈值VL，最大电压VT，或信号能量的脉冲频率使用声发射来进行状态监测具有许多优点。
一小部分传感器，处于策略性部署，能调查整个机械系统。
一个发射源可以通过不同次数的排放以到达不同的传感器。
它的高灵敏度已经被提到。
这也是很容易被记录的;并且声发射测量仪器重量轻而且体积小。
然而，它也有一些缺点。
这些传感器必须直接连接到被监视系统：这会导致长期的可靠性问题。
在嘈杂的条件下可以使之成为不可能孤立的事件。
声发射是很容易受被监视材料的状态的影响，例如热处理，预应变和温度。
此外，由于声发射事件和被监视的系统状态两者关系的特点并不明显，甚至比热辐射测量需要更多的校准或压力测量系统。
在加工过程中，声发射信号的主要来源是剪切带，片工具和工具的工作接触区域，切屑的破碎与碰撞，及其切削工具的特征。
声发射信号的功率比较大，一般见于范围100千赫至300千赫。
其基本性能的研究和检测磨损工具的使用，并且切削已经成为大量调查的主题，例如Iwata和Moriwaki（1977），Kakino （1984），Die i和Dornfeld（1987）。
声发射的使用潜力可以在图5.24看出来。
它显示了一个后刀面磨损VB和振幅水平之间的关系那就是AE信号会转化0.45％的普通碳素钢（Miwa，1981）。
较大的侧面磨损，较大的声发射信号，而与具有耐磨变化切削条件的信号的变化率有关，例如切割速度。
参考文献Boothroyd, G.（1961）金属切削温度的测定摄影技术。
英国J. Appl.物理学. 12，238-242.Chao, B. T., Li, H. L. 和 Trigger, K. J.（1961）对刀腹的表面温度分布的实验研究Trans. ASME J. Eng. Ind. 83, 496–503.Diei，EN和Dornfeld，D. A.（1987）从端面铣削过程的声发射—过程变量的影响。
Trans ASME J. Eng. Ind. 109, 92–99.Friedman, M. Y. and Lenz, E.（1970）切屑表面温度场的测定。
机械工程研究所19（1），395-398.实验理论方法Harris, A., Hastings, W. F.和Mathew, P.（1980）切削温度的试验测量。
见于：Proc. Int. Conf. on Manufacturing Engineering,墨尔本，8月25-27日，第30-35。
Iwata, I. and Moriwaki, T.（1977）对声发射中的应用工具传感进程的磨损。
机械工程研究所26（1），21-26。
Kakino, K.（1984）金属切削和磨削过程声发射监测3，108-116。
Miwa,Y., Inasaki, I. and Yonetsu, S.（1981）用声发射信号故障检测工具的过程，Trans JSME 47, 1680–1689.Reichenbach, G. S.（1958）实验的金属切削温度分布测量。
Trans ASME 80, 525–540.Schwerd, F. (1933) Uber die bestimmung des temperaturfeldesbeimspanablauf. Zeitschrift VDI 77,211–216.Shaw, M. C. (1984) 金属切削原理。
牛津：Clarendon出版社。
Trent, E. M. (1991) 金属切削第三版。
牛津：北海海涅曼。
Ueda, T., Sato, M. and Nakayama, K. (1998) 单晶钻石刀具温度的转变。
CIRP 47(1), 41–44.Williams, J. E, Smart, E. F. and Milner, D. (1970)冶金的加工，第一部分. Metallurgia6力学进展6.1简介第2章介绍了最初的机械，热及摩擦学加工过程的报告。
演示实验的报告研究表明，在剪切面角，摩擦角和前角之间没有独特的的关系;证据表明这部分可能受主剪切带加工硬化;切削速度与高温之间的关系和高应力条件下使摩擦面的摩擦角条件不足的影响。
3至5章集中描述了工件和刀具材料的性能，刀具磨损和故障的本质和加工后的实验方法过程。
这使得针对描述力学进展的背景下，导致有能力来预测从机械加工行为和物理性质的工作及其工具。
本章安排了除本介绍之外的三个部分：滑移线场模型，从而使成连续切屑形成具有很大的启示，但这最终是令人沮丧的，因为它最终没有提供去删除以上所指非唯一性的办法;考虑到建模的工作流引入应力变化的影响这消除了非唯一性，即使只通过一个近似的方式；第一个实例，以对切屑形成的正交模型来扩展更多的一般的三维（非正交）的条件。
这是一个第2章与现代数值（有限元）制作经典材料之间的过渡章节第7章。
6.2滑线场模拟第2章介绍了两个早期的平面的剪切角依赖摩擦和斜角的理论。
根据Merchant（1945）（方程（2.9））切屑的形成发生在一个给定摩擦最低能量的条件下。
据Lee和Shaffer（1951年）（方程（2.10）），剪切面的夹角是由在第二剪切带相关的塑性流动摩擦角规则。
Lee和Shaffer的贡献首次是在slipline 的切屑形成磁场模型。
6.2.1 滑移线场理论滑移线场理论适用于平面应变（二维）的塑性流动。
材料的力学性能被简化为刚性，完全塑料。
这就是说，它的弹性模量被认为是不定的（刚性）及其塑性流动时发生的应用是最大剪应力达到某一临界值，k，它不随条件，如应变，应变率和温度流动的变化而变化。
对于这样一个在平面上的理想化材料，应变塑性状态，滑移线场理论发展的压力和速度如何可以改变规则。
这些被认为是在详细附录1之中。
一个简短的部分在这里给出了摘要，足以使该理论应用到加工中。
首先：什么是滑移线和滑移线场;以及他们有用吗？一个平面材料的应力应变加载的分析结论是，在任何一点上都有两个正交方向，其中剪应力方向为最大值。
此外，在这些方向直接应力是平等的（和平等的静水压力）。
然而，这些方向可以从一个点到另一个点而改变。
如果材料是加载塑性，应力状态完全是所描述的最大剪应力常数K值，以及方向和静水压力各不相同的点。
A线，一般弯曲，沿其长度最大剪应力方向都被称为滑移线。
一个滑移线是正交曲线滑移在塑料地带现有生产线配套。
滑线场理论是构建在特定情况下的滑移线场（例如规则加工）和计算领域内的静水压力的变化之上。
该文章摘自：Metal MachiningTheory and ApplicationsThomas ChildsUniversity of Leeds,UKKatsuhiro MaekawaIbaraki University,JapanToshiyuki ObikawaTokyo Institute of Technology,JapanYasuo YamaneHiroshima University,JapanCopublished in North,Central and South America byJohn Wiley & Sons Inc.,605 Third Avenue,New York,NY 10158–0012Experimental methods(Chao et al.,1961) and on the chip surface (Friedman and Lenz,1970). With the development of infrared sensitive photographic film,temperature fields on the side face of a chipand tool have been recorded (Boothroyd,1961) and television type infrared sensitive video equipment has been used by Harris et al. (1980).Infrared sensors have continued to develop,based on both heat sensing and semiconductor quantum absorption principles. The sensitivity of the second of these is greater than the first,and its time constant is quite small too in the range of ms to ms. Figure 5.21 shows a recent example of the use of the second type. Two sensors,anInSb type sensitive in the 1 mm to 5 mm wavelength range and a HgCdTetype,sensitive from 6 mm to 13 mm, were used:more sensitive temperature measurements may be made by comparing the signals from two different detectors.Most investigations of temperature in metal cutting have been carried out to understand the process better. In principle,temperature measurement might be used for condition monitoring,for example to warn if tool flank wear is leading to too hot cutting conditions. However,particularly for radiant energy measurements and in production conditions,calibration issues and the difficulty of ensuring the radiant energy path from the cutting zone to the detector is not interrupted,make temperature measurement for such a purpose not reliable enough. Monitoring the acoustic emissions from cutting isFig. 5.21 Experimental set-up for measuring the temperature of a chip’s back surface at the cutting point, using a diamond tool and infrared light, after Ueda et al. (1998)Acoustic emission 155 anotherway,albeit an indirect method,to study the state of the process,and this is considered next.5.4Acoustic emissionThe dynamic deformation of materials – for example the growth of cracks,the deformation of inclusions,rapid plastic shear,even grain boundary and dislocation movements is accompanied by the emission of elastic stress waves. This is acoustic emission (AE).Emissions occur over a wide frequency range but typically from 100kHz to 1MHz.Although the waves are of very small amplitude,they can be detected by sensors madefrom strongly piezoelectric materials,such as BaTiO3 or PZT (Pb(Zr x Ti1–x)O3; x = 0.5 to0.6).Figure 5.22 shows the structure of a sensor. An acoustic wave transmitted into thesensor causes a direct stress E(DL/L) where E is the sensor’s Young’s modulus,L is itlength and DL is its change in length. The stress creates an electric fieldT = g33E(DL/L)(5.7a)where g33is the sensor material’s piezoelectric stress coefficient. The vol tage across thesensor,TL,is thenV = g33EDL (5.7b)Typical values of g33 and E for PZT are 24.4 × 10–3 Vm/N and 58.5GPa. It is possible,withamplification,to detect voltages as small as 0.01 mV. These values substituted intoequation (5.7b) lead to the possibility of detecting length changes DL as small as 7 ×10–15m:for a sensor with L= 10mm,that is equivalent to a minimum strain of 7 × 10–13. AEFig. 5.22 Structure of an AE sensor156 Experimental methodsFig. 5.23 An example of an AE signal and signal processingstrain sensing is much more sensitive than using wire strain gauges,for which the minimum detectable strain is around 10–6.The electrical signal from an AE sensor is processed in two stages. It is first passedthrough a low noise pre-amplifier and a band-pass filter (≈100kHz to 1MHz). The resulting signal typically has a complicated form,based on events,such as in Figure 5.23. In thesecond stage of processing,the main features of the signal are extracted,such as thenumber of events,the frequency of pulses with a voltage exceeding some threshold valueVL,the maximum voltage VT,or the signal energy.The use of acoustic emission for condition monitoring has a number of advantages. Asmall number of sensors,strategicallyplaced,can survey the whole of a mechanicalsystem. The source of an emission can be located from the different times the emissiontakes to reach different sensors. Its high sensitivity has already been mentioned. It is alsoeasy to record; and acoustic emission measuring instruments are lightweight and small.However,it also has some disadvantages. The sensors must be attached directly to thesystem being monitored:this leads to long term reliability problems. In noisy conditions itcan become impossible to isolate events. Acoustic emission is easily influenced by thestate of the material being monitored,its heat treatment,pre-strain and temperature. Inaddition,because it is not obvious what is the relationship between the characteristics ofacoustic emission events and the state of the system being monitored,there is even moreneed to calibrate or train the measuring system than there is with thermal radiationmeasurements.In machining,the main sources of AE signals are the primary shear zone,the chip–tooland tool–work contact areas,the breaking and collision of chips,and the chipping andfracture of the tool. AE signals of large power are generally observed in the range 100kHzto 300kHz. Investigations of their basic properties and uses in detecting tool wear andchipping have been the subject of numerous investigations,for example Iwata andMoriwaki (1977),Kakino (1984) and Diei and Dornfeld (1987). The potential of using AEis seen in Figure 5.24. It shows a relation between flank wear VB and the amplitude levelReferences 157Fig. 5.24 Relation between flank wear VB and amplitude of AE signal, after Miwa et al. (1981)of an AE signal in turning a 0.45% plain carbon steel(Miwa,1981). The larger the flankwear,the larger the AE signal,while the rate of change of signal with wear changes withthe cutting conditions,such as cutting speed.ReferencesBoothroyd,G. (1961) Photographic technique for the determination of metal cutting temperatures.British J. Appl. Phys. 12,238–242.Chao,B.T.,Li,H.L. and Trigger,K.J. (1961) An experimental investigation of temperature distribution at tool flank surface. Trans. ASME J. Eng. Ind. 83,496–503.Diei,E.N. and Dornfeld,D.A. (1987) Acoustic emission from the face milling process – the effectsof process variables. Trans ASME J. Eng. Ind. 109,92–99. Friedman,M.Y. and Lenz,E. (1970) Determination of temperature field on upper chip face. AnnalsCIRP 19(1),395–398.158 Experimental methodsHarris,A.,Hastings,W.F. and Mathew,P. (1980) The experimental measurement of cutting temperature. In: Proc. Int. Conf. on Manufacturing Engineering,Melbourne,25–27 August,pp. 30–35.Iwata,I. and Moriwaki,T. (1977) An application of acoustic emission to in-process sensing of toolwear. Annals CIRP 26(1),21–26.Kakino,K. (1984) Monitoring of metal cutting and grinding processes by acoustic emission. J.Acoustic Emission 3,108–116.Miwa,Y.,Inasaki,I. and Yonetsu,S. (1981) In-process detection of tool failure by acoustic emissionsignal. Trans JSME 47,1680–1689.Reichenbach,G.S. (1958) Experimental measurement of metal cutting temperature distribution.Trans ASME 80,525–540.Schwerd,F. (1933) Uber die bestimmung des temperaturfeldesbeimspanablauf. Zeitschrift VDI 77,211–216.Shaw,M.C. (1984) Metal Cutting Principles. Oxford:Clarendon Press.Trent,E.M. (1991) Metal Cutting,3rd edn. Oxford:Butterworth Heinemann.Ueda,T.,Sato,M. and Nakayama,K. (1998)The temperature of a single crystal diamond tool inturning. Annals CIRP 47(1),41–44.Williams,J.E,Smart,E.F. and Milner,D. (1970) The metallurgy of machining,Part 1. Metallurgia6Advances in mechanics6.1IntroductionChapter 2 presented initial mechanical,thermal and tribological considerations of themachining process. It reported on experimental studies that demonstrate that there is nounique relation between shear plane angle,friction angle and rake angle; on evidence thatpart of this may be the influence of workhardening in the primary shear zone; on hightemperature generation at high cutting speeds; and on the high stress conditions on the rakeface that make a friction angle an inadequate descriptor of friction conditions there.Chapters 3 to 5 concentrated on describing the properties of work and tool materials,thenature of tool wear and failure and on experimental methods of following the machiningprocess. This sets the background against which advances in mechanics may be described,leading to the ability to predict machining behaviours from the mechanical and physicalproperties of the work and tool. This chapter is arranged in three sections in addition to this introduction:an account ofslip-line field modelling,which gives much insight into continuous chip formation butwhich is ultimately frustrating as it offers no way to remove the non-uniqueness referredto above; an account of the introduction of work flow stressvariation effects intomodelling that removes the non-uniqueness,even though only in an approximate manner in thefirst instance; and an extension of modelling from orthogonal chip formation to moregeneral three-dimensional (non-orthogonal) conditions. It is a bridgingchapter,betweenthe classical material of Chapter 2 and modern numerical (finite element) modelling inChapter 7.6.2Slip-line field modelingChapter 2 presented two early theories of the dependence of the shear plane angle on thefriction and rake angles. According to Merchant (1945) (equation (2.9)) chip formationoccurs at a minimum energy for a given friction condition. According to Lee and Shaffer(1951) (equation (2.10)) the shear plane angle is related to the friction angle by plastic flowrules in the secondary shear zone. Lee and Shaffer’s contribution was the first of the slipline field models of chip formation.160 Advances in mechanics6.2.1Slip-line field theorySlip-line field theory applies to plane strain (two-dimensional) plastic flows. A material’smec hanical properties are simplified to rigid,perfectly plastic. That is to say,its elasticmoduli are assumed to be infinite (rigid) and its plastic flow occurs when the applied maximum shear stress reaches some critical value, k,which does not vary with conditions ofthe flow such as strain,strain-rate or temperature. For such an idealized material,in a planestrain plastic state,slip-line field theory develops rules for how stress and velocity can vary from place to place. These are considered in detail in Appendix 1. A brief and partialsummary is given here,sufficient to enable the application of the theory to machining tobe understood.First of all:what are a slip-line and a slip-line field; and how are they useful? The analysis of stress in a plane strain loaded material concludes that at any point there are two orthogonal directions in which the shear stresses are maximum. Further,the direct stresses are equal(and equal to the hydrostatic pressure) in those directions. However,those directions can varyfrom point to point. If the material is loaded plastically,the state of stress is completelydescribed by the constant value k of maximum shear stress,and how its direction and thehydrostatic pressure vary from point to point. A line,generallycurved,which is tangentialall along its length to directions of maximum shear stress is known as a slip-line. A slip-linefield is the complete set of orthogonal curvilinear slip-lines existing in a plastic region. Slip-line field theory provides rules for constructing the slip-line field in particular cases (such asmachining) and for calculating how hydrostatic pressure varies within the field.Article from ：Metal MachiningTheory and ApplicationsThomas ChildsUniversity of Leeds,UKKatsuhiro MaekawaIbaraki University,JapanToshiyuki ObikawaTokyo Institute of Technology,JapanYasuo YamaneHiroshima University,Japan Copublished in North,Central and South America by John Wiley & Sons Inc.,605 Third Avenue,New York,NY 10158–0012。