谁能翻译这段英文，化学专业方面的，很难

幸运的想吧 2009-02-21 00:33:53 437 浏览

This work examines the behaviour of fluorine modified b-PbO2 electrodes in the processes of O2 and O3 evolution in sulphuric acid. The electrochemical kinetic analyses of these processes are based on quasi-steady-state polarisation and impe... This work examines the behaviour of fluorine modified b-PbO2 electrodes in the processes of O2 and O3 evolution in sulphuric acid. The electrochemical kinetic analyses of these processes are based on quasi-steady-state polarisation and impedance data. The good agreement between the two sets of measurements allows some basic conclusions to be drawn. In particular， the O2 evolution process is always inhibited at F-doped PbO2 electrodes， and impedance results suggest possible changes in the mechanism， with electrodesorption of intermediates becoming more important as the concentration of the doping element increases. The interpretation of the data for the less positive potentials region invokes the specific adsorption of SO4 as a factor influencing the kinetics of O2 evolution. The current efficiency for O3 formation as a function of the amount of NaF added to the PbO2 growth solution reaches a maximum for a concentration of 0.01 mol dm3. A plausible cause for the decrease on the higher concentration side is the discharge of adsorbed SO4 2 (or HSO4 ) eventually yielding persulphate. This reaction is known to be favoured in the presence of a relatively high amount of fluoride in the electrolyte. An analysis of the results of modified neglect of diatomic differential overlap (MNDO) calculations on Pb cluster models and of X-ray photoelectron spectroscopy (XPS) data suggests that the coverage by weakly adsorbed oxygen species (OH and H2O) is an important parameter that is influenced by F-doping. © 1999 Elsevier Science Ltd. All rights reserved. 展开

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紅塵曲鎮魂調 2009-02-22 00:00:00

这项工作检查的行为：氟改性β -二氧化铅电极过程中的O2和O3的演变硫酸。电化学动力学分析这些过程是基于准稳态极化和交流阻抗数据。好之间的协议两套允许一些基本的测量得出的结论。特别是， O2的进化过程中始终是YZ的F掺杂二氧化铅电极，和阻抗结果表明可能发生的变化的机制，准稳态极化和交流阻抗数据的中间体越来越重要. 掺杂浓度的因素增加。解释的数据不太积极的潜力区域援引具体的吸附硫酸作为一个影响因素的动力学氧演变。电流效率对臭氧形成的函数的数额氟化钠加入二氧化铅增长的解决办法达到的Z高浓度为0.01摩尔马克。的可行的减少引起的高浓度一侧是放电吸附硫酸（或HSO4 ）Z终收益硫酸钾。这种反应被认为是赞成存在相对较高的数额中氟化物电解质。分析的结果，修改忽略双原子微分重叠（ MNDO ）计算铅簇模型和X射线光电子能谱（ XPS ）的数据表明，覆盖范围由弱吸附氧物种（ OH和水）是一个重要的参数，受到的F -兴奋剂。 © 1999埃尔塞维尔科技有限公司.

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天秤三次元直男 2009-02-22 00:00:00

这项工作检查的行为，氟改性β -二氧化铅电极过程中的O2和O3的演变硫酸。电化学动力学分析这些过程是基于准稳态极化和交流阻抗数据。好之间的协议两套允许一些基本的测量得出的结论。特别是， O2的进化过程中始终是YZ的F掺杂二氧化铅电极，和阻抗结果表明可能发生的变化的机制， electrodesorption中间体越来越重要的掺杂浓度的因素增加。解释的数据不太积极的潜力区域援引具体的吸附硫酸作为一个影响因素的动力学氧演变。电流效率对臭氧形成的函数的数额氟化钠加入二氧化铅增长的解决办法达到的Z高浓度为0.01摩尔马克？ 3 。的可行的减少引起的高浓度一侧是放电吸附硫酸2 ？（或HSO4 ）Z终收益硫酸钾。这种反应被认为是赞成存在相对较高的数额中氟化物电解质。分析的结果，修改忽略双原子微分重叠（ MNDO ）计算铅簇模型和X射线光电子能谱（ XPS ）的数据表明，覆盖范围由弱吸附氧物种（ OH和水）是一个重要的参数，受到的F -兴奋剂。 © 1999埃尔塞维尔科技有限公司All rights reserved 。

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对你无限的奉献 2009-02-22 00:00:00

这项工作检查的行为，氟改性β -二氧化铅电极过程中的O2和O3的演变硫酸。电化学动力学分析这些过程是基于准稳态极化和交流阻抗数据。好之间的协议两套允许一些基本的测量得出的结论。特别是， O2的进化过程中始终是YZ的F掺杂二氧化铅电极，和阻抗结果表明可能发生的变化的机制， electrodesorption中间体越来越重要的浓度的增加兴奋剂元素，解释的数据不太积极的潜力区域援引具体的吸附硫酸作为一个影响因素的动力学氧演变。电流效率对臭氧形成的函数的数额氟化钠加入二氧化铅增长的解决办法达到的Z高浓度为0.01摩尔管理部3 。的可行的减少引起的高浓度一侧是放电硫酸2吸附（或HSO4 ）Z终收益硫酸钾。这种反应被认为是赞成存在相对较高的数额中氟化物电解质。分析的结果，修改忽略双原子微分重叠（ MNDO ）计算铅簇模型和X射线光电子能谱（ XPS ）的数据表明，覆盖范围由弱吸附氧物种（ OH和水）是一个重要的参数，受到的F -兴奋剂。 © 1999埃尔塞维尔科技有限公司保留所有权利。

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雄安任 2009-02-22 00:00:00

终于好了，辛苦了十五分钟，个人很满意这个工作测试了硫酸环境下氧气和臭氧转化中用氟处理过的b-二氧化铅电极的性能。对这些过程的电化学动力学分析基于近似稳定状态的极化和阻抗数据。两组数据的良好吻合可以推出一些基本结论。特别的，氧气转化反应总是在含氟二氧化铅电极附近被YZ，并且阻抗数据表明装置可能会发生变化，中间产物对电极的吸附随着添加物比例的增加而增加。对电正性较弱区域数据的解读说明特定的SO4的吸收是影响O2转化过程动力学的一个因素。现在O3转化的效率，当二氧化铅内氟化钠添加浓度为0.01mol/L时达到Z大值。对于更高浓度下效率的下降，一个可以接受的解释是吸收的SO4 2(或HSO4)可能产生过硫酸。这个反应当电解质内氟的含量较多时更易发生。一个关于MNDO法对于铅团簇模型以及X射线光电子能谱(XPS)的计算结果的分析表明，轻度吸收的氧族(OH和H2O)的覆盖是一个被添加氟所影响的重要参数。本人不是化学专业的，所以有些术语欠妥。另外Z后一句不大通顺，Z好另外请教高人。

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陕西筑龙建筑 2009-02-22 00:00:00

该书检视b-PbO2的行为中氟修改电极的进化过程中O2和臭氧硫酸。分析了电化学动力学过程是基于quasi-steady-state和阻抗数据的分化。良好的之间的协议两套测量的基本结论是允许一些结论。在特殊情况下，O2演化过程中总是压抑在F-doped二氧化铅电极、阻抗结果显示可能的变化机制，以electrodesorption中间体变得更重要的掺杂元素浓度的增加。对资料的解释为少的特定区域召唤积极的潜力的吸附SO4作为影响因子动力学演化O2)。电流效率为O3形成一个函数的名称加入二氧化铅增长达到Z大溶液浓度对注塑件dm3 0.01%。一个似是而非的原因在更高浓度的降低是放电 2(或者对吸附SO4)Z终屈服persulphate HSO4。这种反应被视为主张在存在较高的含氟在电解质。分析结果对改性忽略了双原子微分重叠(MNDO)的计算模型，对铅集群的x射线光电子能谱(XPS)数据显示范围由弱吸附氧(哦，水)是一种重要的参数，是受F-doping卷。1999年。版权所有。

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恋池水瓶 2009-02-23 00:00:00

此帖确实如楼主所说“很难”，但请楼主仔细审阅我的翻译，谢谢！ This work examines the behaviour of fluorine modified b-PbO2 electrodes in the processes of O2 and O3 evolution in sulphuric acid. 本研究旨在验证b－PbO2电极在O2和O3于硫酸中析出过程中的性状。The electrochemical kinetic analyses of these processes are based on quasi-steady-state polarisation and impedance data. 这些过程的电化学动力学分析以准稳态极化数据和阻抗数据为基础。The good agreement between the two sets of measurements allows some basic conclusions to be drawn.由于两组测量值之间良好的一致性，所以可以得出一些基本的结论。 In particular， the O2 evolution process is always inhibited at F-doped PbO2 electrodes， and impedance results suggest possible changes in the mechanism， with electrode sorption of intermediates becoming more important as the concentration of the doping element increases. 特别是，O2的析出过程总是在掺F（氟）的PbO2电极处被YZ，而阻抗的结果表明了机理方面可能的改变，即电极对中间体的吸附作用随着掺杂元素浓度的增加而变得更为重要了。The interpretation of the data for the less positive potentials region invokes the specific adsorption of SO4 as a factor influencing the kinetics of O2 evolution. 对于正电位较小区域的数据的判读，调用了SO4作为影响O2析出动力学的一个因素的特定吸附作用。The current efficiency for O3 formation as a function of the amount of NaF added to the PbO2 growth solution reaches a maximum for a concentration of 0.01 mol dm3. 对于O3形成的电流效率，作为添加到PbO2生长溶液中的NaF量的函数，在0.01 mol dm3浓度下达到一Z大值。 A plausible cause for the decrease on the higher concentration side is the discharge of adsorbed SO4 2 (or HSO4 ) eventually yielding persulphate. 在较高浓度侧的降低，其貌似合理的原因是，被吸附的SO42(或HSO4)的排出（discharge）Z终产生了过硫酸盐。This reaction is known to be favoured in the presence of a relatively high amount of fluoride in the electrolyte. 已知，这一反应在电解液中存在相对大量氟化物时更为有利。 An analysis of the results of modified neglect of diatomic differential overlap (MNDO) calculations on Pb cluster models and of X-ray photoelectron spectroscopy (XPS) data suggests that the coverage by weakly adsorbed oxygen species (OH and H2O) is an important parameter that is influenced by F-doping. © 1999 Elsevier Science Ltd. All rights reserved. 对Pb（铅）原子簇模型改进的忽略双原子微分重叠（MNDO）计算结果的分析，以及X射线光电子能谱（XPS）数据结果的分析表明，由弱吸附的氧物质（OH和H2O）的覆盖是一个受F（氟）掺杂影响的重要的参数。 1999年Elsevier Science Ltd. 保留所有权利

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谁能翻译这段英文，化学专业方面的，很难: This work examines the behaviour of fluorine modified b-PbO2 electrodes in the processes of O2 and O3 evolution in sulphuric acid. The electrochemical kinetic analyses of these processes are based on quasi-steady-state polarisation and impe... This work examines the behaviour of fluorine modified b-PbO2 electrodes in the processes of O2 and O3 evolution in sulphuric acid. The electrochemical kinetic analyses of these processes are based on quasi-steady-state polarisation and impedance data. The good agreement between the two sets of measurements allows some basic conclusions to be drawn. In particular， the O2 evolution process is always inhibited at F-doped PbO2 electrodes， and impedance results suggest possible changes in the mechanism， with electrodesorption of intermediates becoming more important as the concentration of the doping element increases. The interpretation of the data for the less positive potentials region invokes the specific adsorption of SO4 as a factor influencing the kinetics of O2 evolution. The current efficiency for O3 formation as a function of the amount of NaF added to the PbO2 growth solution reaches a maximum for a concentration of 0.01 mol dm3. A plausible cause for the decrease on the higher concentration side is the discharge of adsorbed SO4 2 (or HSO4 ) eventually yielding persulphate. This reaction is known to be favoured in the presence of a relatively high amount of fluoride in the electrolyte. An analysis of the results of modified neglect of diatomic differential overlap (MNDO) calculations on Pb cluster models and of X-ray photoelectron spectroscopy (XPS) data suggests that the coverage by weakly adsorbed oxygen species (OH and H2O) is an important parameter that is influenced by F-doping. © 1999 Elsevier Science Ltd. All rights reserved. 展开

测序方面的生物专业英文句子翻译: The cDNA and gene sequences currently available includes 31，741 unique sequences assembled from 217，519 high quality 454 sequencing reads.这句怎么翻译？尤其是high quality 454 sequencing reads具体怎么翻译

谁能帮我翻译一下这段英文文献啊: Fig. 1 shows that diamond particles are dispersed in the copper matrix. Since the diamond particles are easy to be stripped off during mechanical polishing， small pits are left on the surface of samples. When the samples were analyzed b... Fig. 1 shows that diamond particles are dispersed in the copper matrix. Since the diamond particles are easy to be stripped off during mechanical polishing， small pits are left on the surface of samples. When the samples were analyzed by electron probe for carbon， the particles displayed high carbon peaks， as shown in Fig. 2. Fig. 3 exhibits the analyzed result for extracted product of the copper–diamond composite by X-ray diffraction (XRD) analysis. It is shown that three dif- fraction peaks exist， shown as A， B and C， respectively. The interplanar distances corresponding to the three peaks and standard ones for diamond are compared in Table 1. The measured values of the interplanar distances are in good agreement with the standard ones， demon- strating that the extracted product should be the carbon in diamond state. Fig. 4(a) gives a TEM micrograph showing distribution and morphology of diamond particles (indicated as A， B， and C) in the copper–diamond composite. The calibration of interplanar distance for diffraction rings in Fig. 4(b) was given in Table 2. Compared to Table 1， it is also demon- strated that the calibrated interplanar distances for the diffraction rings conform to the standard ones of diamond. Therefore， it is believed that the graphitization of diamond particles hardly occurs after sintering at 1150–1220 K in the copper–diamond composite. Although diamond is a metastable allotropic modifica- tion of carbon， the graphitization of diamond particles in the copper–diamond composite did not occur， or the degree of graphitization was too small to be found. It is believed that the beginning temperature of graphi- tization would be associated with the purity of diamond powders. The impurities such as some metallic elements reduce the beginning temperature of diamond graphitiza- tion. When diamond is fabricated by the static synthesis method， Fe and Ni are often used as catalysts and are present in diamond as impurities to decrease the beginning temperature of graphitization [6]. It is understandable that both for the graphitization and its reverse reactions， their activation energies can be decreased by catalytic agents. Compared with the diamond fabricated by static synthesis， the diamond powders prepared by explosion method do not contain metallic impurities， thus leading to an obvious increase in the beginning temperature of graphitization. Hence， the detonation synthetic diamond might be more resistant to graphitization and probably suitable for the electric contact materials. 展开

通信方面的英文文献翻译！！: 以下是文献的一部分，愿意帮忙的高手留下邮箱，我把文件发给你，若能完成，加分：SpatialCompressiveSensingApproachForFieldDirectionalityEstimation.I.INTRODUCTIONVarietyoft... 以下是文献的一部分，愿意帮忙的高手留下邮箱，我把文件发给你，若能完成，加分： Spatial Compressive Sensing Approach For Field Directionality Estimation. I. INTRODUCTION Variety of techniques for field directionality estimation were studied in literature [1]-[5]. Thus， a theoretical analysis of the relationship between the hydrophone array output and the noise field was conducted in [1]-[5]. The developed techniques were based on the array beamformer output or the crossspectral matrix between outputs of array elements [4]-[5]. The problem of a field directionality estimation in ocean， using horizontal line towed array was also addressed in literature [5]- [8]. Recently， problems of direction of arrival and field directionality estimation for moving sensors arrays have attracted renewed interest [9]-[12]. It was shown that an array motion can improve an array performance assuming temporal coherence of successive samples [10]-[11]. In [12]， the wavefield sampling method that exploits the linear relationship between the noise field and the collection of beamformer outputs over various array orientations was proposed. It was shown that the wavefield sampling (WS) method outperforms other tested methods. This algorithm was implemented via the recursive estimation method and its convergence to the unique solution was promised for a specific set of array orientations and beamformer look directions. However， a method for a proper array orientation and beamformer look direction sequence selection remains an open question. The quality of the field directionality estimation is determined by the angular resolution. The higher angular resolution is， the more accurate estimation of the far field sources， and better detection performance can be achieved. One of fundamental relations in the array signal processing is that the angular resolution is directly proportional to the number of the array elements [13]. This relation motivates the desire for longer arrays that can achieve higher resolution. Unfortunately， the requirement contradicts the implementation and installation limitations that motivate shorter arrays. Moreover， implementation of longer arrays for maneuvering platforms such as unmanned underwater vehicles (UUV) can even be impossible [14]. These contradictions motivate the quest for alternative array signal processing methods. Usually， the field directionality is modeled as a finite set of strong far-field narrow-band sources and an isotropic lowpower noise [1]. In this work， the model of the field directionality is adopted in the following way. First， the bearing angle space is uniformly sampled into a large number of discrete angles. Next， it is assumed that ether the high energy that corresponds to the far-field strong sources or the low-energy that corresponds to the isotropic noise is received at the sensor array from every of these discrete azimuth angles. 展开

急求翻译下面这段测绘工程方面的文章: REAL-TIME KINEMATIC GPS Real-Time Kinematic (RTK) is Trimble Navigation's Site Surveyor System available as a standard option upgrade to Trimble's 4000 series SE and SSE receivers. The Medicine Bow National Forest uses 4000 SSE and SE rece... REAL-TIME KINEMATIC GPS Real-Time Kinematic (RTK) is Trimble Navigation's Site Surveyor System available as a standard option upgrade to Trimble's 4000 series SE and SSE receivers. The Medicine Bow National Forest uses 4000 SSE and SE receivers in it's Boundary Management program. The use of RTK enables a surveyor to determine a corner's position， establish a corner without having to make traditional corner moves or to mark and post line as quickly as the surveyor could walk， all without having to post-process the data. The surveyor using RTK can perform corner search within a meter or a couple of centimeters of the true location without the need to traverse down the line. For some survey applications traditional kinematic GPS field procedures are preferred， since many points can be observed in a short period of time with occupation times of a minute or less. However until now， kinematic surveying required post-processing before the results were available. This made field stakeout of corner positions， corner search， line marking and posting， and evaluation of coordinate accuracy in the field impossible to do using kinematic techniques (Curry et al 1993). Now， the use of RTK technology makes these impossible traditional kinematic tasks possible. What is RTK? RTK is currently carrier phase observations processed (corrected) in real-time resulting in position coordinates to a 1-2 centimeter accuracy level being available to the surveyor in the field. In other words， what the surveyor sees is what he gets. RTK， consists of two or more GPS receivers， three or more radio-modems， a "fixed-plate initializer" ， and a handheld survey data collector/computer (TDC1). In RTK， one receiver occupies a known reference station and broadcasts a correction message (Compact Measurement Record or CMR2) to one or more roving receivers. The roving receivers process the information to solve the WGS-84 vectors by solving the integers in real-time within the receiver to produce an accurate position relative to the reference station. Precision of RTK is +/-2 cm + 2 ppm， with 1 ppm equating to 1 mm per 1 km (Trimble Navigation， 1993). The TDC1 is used to graphically display the processed results of the surveyors current position on the ground at that moment. The TDC1 has the capability for the surveyor to navigate within a couple of centimeters to a known or unknown coordinate position using Local， State Plane or Geographic coordinates. In real-time positions may be logged in the field， inverses performed， attributes (features) recorded， azimuths and distances between points calculated， and corners located. RTK， as with traditional kinematic GPS procedures， currently requires continuous satellite lock to be maintained. This restriction allows for RTK to be most effective in a non-canopied， no obstructions environment. 展开

请翻译一下这段英文1，谢谢: Materials For the present study， the matrix was ABS supplied by Formosa Co. The reinforcements were polyacrylonitrile based high strength CFs. The properties of materials used were given in Table 1. Carbon fibre surface treatment Carbon fi... Materials For the present study， the matrix was ABS supplied by Formosa Co. The reinforcements were polyacrylonitrile based high strength CFs. The properties of materials used were given in Table 1. Carbon fibre surface treatment Carbon fibres were oxidised by boiling in HNO3 under reflux for 5 h (T5120uC). Afterwards， the nitric acid oxidised fibres were washed with distilled water to neutral pH. Fibre surface composition The fibres were characterised by X-ray photoelectron spectroscopy (ESCA 300， Scienta， Sweden) to determine the level of functionalisation of the modified fibres. An initial survey scan was performed to determine the detectable elements， followed by high resolution scans. The entire X-ray photoelectron spectrum was energy referenced to the C1s peak of graphite (bending energy5284?5 eV). Composite preparation Before processing， ABS pellets and CFs were dried in a vacuum oven for 4 h at 80uC. Composites containing 0， 5， 10， 15， 20， 25 and 30 wt-% SCF were prepared by melt mixing in a co-rotating twin screw extruder (Thermoprism TSE 16 TC， L/D:24). The ABS pellets and CFs were fed from the main and side feeders respectively. The molten composite obtained from the die of the extruder was water cooled and pelletised. The extrusion conditions were arranged， as shown in Table 2. The viscosity of the melt containing CFs depends on the viscosity of the polymer matrix as well as the processing temperature. To avoid unfavourable shearing conditions， the melt temperature is kept as high as possible regarding thermal degradation. Before PA6 was blended to promote interfacial adhesion， vacuum drying of the ABS and PA6 pellets was carried out at 80uC for 4 and 12 h respectively. The 0， 10， 20 and 30 wt-% PA6 containing batches were fed through the main feeder to the twin screw extruder. The extrudate was water cooled and chopped into small pellets. The produced ABS/PA6 pellets were vacuum dried again at 80uC for 12 h. To prepare the SCF reinforced ABS/PA6 composites， the blend was introduced into the twin screw extruder from the main feeder， and SCFs were fed from the side feeder. The twin screw extruder was operated at the same processing conditions used during the blend preparation. The extrudate was again water cooled and chopped into small pellets. The extrusion grades of resin were used to make the extrudate form fully. The specimens for the mechanical characterisation experiments were moulded using a laboratory scale injection moulding machine (microinjector， model 1998; Daca Instruments) at a barrel temperature of 230uC and mould temperature of 80uC. The injection moulding machine used in this study was a laboratory type microinjector. The principle of the operation is that the preweighed (，2?5 g) raw material is loaded into the cylindrical barrel and allowed to melt at a preset barrel temperature for 1 min.Then the molten plastic is pushed through an injection tip by a piston. 展开

翻译英文~专业类的: Whilegraphene，acarbon-basedtwo-dimensionalnanomaterials，hasreceivedanupsurgeofinterest，[1]self-assemblyofsmallorganicandorganometallicmoleculesinto2Dnanostructurescouldal... While graphene， a carbon-based two-dimensional nanomaterials， has received an upsurge of interest，[1] self-assembly of small organic and organometallic molecules into 2D nanostructures could also be harnessed to develop new classes of functional supramolecular nanomaterials.[2] In principle， quasi-2D lamellae or nanosheets are planar structures having a thickness less than 100 nm and lateral dimensions a few orders of magnitude greater than their thickness. Control over the bilateral intermolecular noncovalent interactions is anticipated to organize small molecules into regular 2D nanostructures， which has been a formidable challenge yet to be achieved. Recently， Shelnutt and co-workers obtained discrete porphyrin nanosheets reprecipitated from their solutions;[3] Sathish and co-workers constructed hexagonal C60 nanosheets using a liquid–liquid interfacial precipitation method;[4] the groups of Yao[5] and Hu[6] prepared singlecrystalline nanosheets of polycyclic aromatics using a surfactant- assisted reprecipitation and a physical vapor transporting method， respectively; and Zhang and co-workers suggested that molecules with intramolecular charge-transfer dipole moments could be grown into quasi-2D nanostructures.[7] Moreover， some amphiphiles and organogelators were found to self-organize into sheet-like nanostructures in contact with solvents.[8] Despite these advances， templateand surfactant-free synthesis of free-standing， crystalline， and optoelectronically active nanosheets from small molecules remains elusive. 展开

？？？？？谁能帮我翻译几个英文——激光雷达？？？？？: 关于激光雷达的论文 1、LO 2、header board 3、inductive beams

有关机械液压方面的英文资料及翻译，翻译的字数5000以上！谢谢！！:

这段韩语怎么翻译:

化学专业英语翻译不要翻译工具: D，L252单取代海因是工业生产D2氨基酸的重要前体[1～3]。海因酶具有底物特异性，D2海因酶(EC3151212)可转化外消旋的D，L252单取代海因中的D型消旋体成为D2N2氨甲酰氨基酸，剩余的L252单取... D ，L252单取代海因是工业生产 D2氨基酸的重要前体[1～3 ]。海因酶具有底物特异性，D2海因酶(EC 3151212)可转化外消旋的D ，L252单取代海因中的D型消旋体成为D2N2氨甲酰氨基酸，剩余的L252单取代海因由于完全不被 D2海因酶所作用，如图 1所示，先进行消旋，从而使得 D ，L2海因完全转化为光学纯的 D2N2氨甲酰氨基酸，并进一步被转化为D2氨基酸。因此，52单取代海因的自发消旋成为L2或D2N2氨甲酰氨基酸生产中的一个重要的步骤。若海因的自发消旋速率远低于海因水解酶的水解速率，则海因的消旋将成为D2N2氨甲酰氨基酸生产中的一个限速步骤。目前关于 52单取代海因的消旋的文献非常少，海因消旋的细节问题也没有被完全揭示。 1 材料与方法 111 实验材料 L2丙氨酸(国家生化工程ZX) 、 L2苯丙氨酸(国家生化工程ZX) 、氰酸钠(江都化工厂) ，其他试剂为国产分析纯试剂。 112 实验方法 11211 52取代海因衍生物的制备采用Henze2Speer法[4～5 ]进行52取代海因衍生物的制备: 反应温度为60～80 ℃。反应6 h后，加入盐酸酸化，继续加热 8 h ，冷却后过滤得到的固体用酒精和水的混合溶液重结晶，得到无色晶状目的产物。因使用的氨基酸不同，反应条件略有变化，产率一般为40 %～80 % ，所得的52取代海因具有和底物氨基酸相同的旋光方向。 11212 海因衍生物的消旋 a.精确称量41000 g L252甲基海因，溶解于蒸馏水中，定容至250 mL ，测定其旋光度，并以此值为未消旋化的起始数据。 b.用 6 mol/ L 的 NaOH溶液调整海因溶液 pH值达810 ，90 ℃水浴2 h ，于旋光仪上测定其旋光度。 c.同 b ，依次调节溶液pH值为710、 810、 910 ，分别测定其旋光度。 d.同 b ，依次于50 ℃水浴中及室温下恒温2 h ，分别测定其旋光度，并与起始数据对比，计算消旋比 r ( %) :r =αt/α0 ，其中αt 为 t 时间溶液的旋光度，α0为溶液初始旋光度。 11213 海因的碱解精确称量41000 g L252甲基海因，溶解于蒸馏水中，定容至 250 mL ，用 NaOH溶液和盐酸分别调至pH = 2、 8、 12 ， 90 ℃水浴反应4 h ，中间取样测定其N2氨甲酰丙氨酸浓度。 11214 海因的转化采用012 %的海因溶液，按 w (底物)∶ w (菌泥)= 1∶ 5的比例，于pH 915 ，温度40 ℃下进行转化。取样:取样10 mL ，加入 5 mL 三停止反应，摇匀，放冰箱待测。 3 结论 311 海因的消旋遵循本文所提出的碳负离子理论，其消旋过程为一级反应动力学过程。由海因消旋的半衰期可看出提高温度和pH对海因的消旋均有利，但pH过高的情况下海因则会发生碱解反应从而造成损失。 312 本文采用的海因转化酶系中所含为 D2海因酶，对D2海因的转化活性非常高，由此可见，如若采用的转化体系中没有消旋酶的存在，则海因的消旋成为海因酶转化生产光学活性氨基酸的一个限速步骤。展开

帮忙翻译一下化工方面的单词英语: 碱值测定器试剂移液管锥形瓶酸式滴定管甲基黄溴甲酚绿混合指示剂盐酸标准溶液摩尔/升酸式滴定管... 碱值测定器试剂移液管锥形瓶酸式滴定管甲基黄溴甲酚绿混合指示剂盐酸标准溶液摩尔/升酸式滴定管展开

谁能提供一些煤炭质量方面的信息: 煤的热量灰分挥发含硫等煤种什么指标的煤能干什么用大体价格现在是多少只有50分希望有个能好好回答的... 煤的热量灰分挥发含硫等煤种什么指标的煤能干什么用大体价格现在是多少只有50分希望有个能好好回答的展开

是软件开发工程师，这段时间经常加班加点做软件方面的项目，: 熬夜了很多次，晚上睡觉也睡不好的，如何解决睡眠质量的问题？

几个日语遥控器方面的专业用语请达人们帮忙翻译一下～谢谢哦: 1.铭板（面贴） 2.红外发射管 3.陶瓷谐振器 4.片阻 5.片容 6.插件电阻 7.导电胶 8. 红胶（邦定用的） 9.黑胶（邦定封胶用的） 10.

翻译以下英文：: The standard error of the mean (SEM) is a measure of how far your sample mean is likely to be from the true population mean. The SEM is calculated by this equation:SEM=SD/N. With large samples， the SEM is always small. By itself， the SEM i... The standard error of the mean (SEM) is a measure of how far your sample mean is likely to be from the true population mean. The SEM is calculated by this equation:SEM=SD/N. With large samples， the SEM is always small. By itself， the SEM is difficult to interpret. It is easier to interpret the 95% confidence interval， which is calculated from the SEM. 展开

高分求高人翻译植物化学英文材料，谢谢: Review Enzymatic protein hydrolysis plays a major role in various physiological processes， including digestion， and is regulated by proteinase inhibitors. Inhibitors in foods and food ingredients can reduce the absorption of free amino aci... Review Enzymatic protein hydrolysis plays a major role in various physiological processes， including digestion， and is regulated by proteinase inhibitors. Inhibitors in foods and food ingredients can reduce the absorption of free amino acids， and can impair protein hydrolysis in industrial processes. However， inhibitors can be useful tools in pest control， in the prevention and treatment of diseases such as cancers and AIDS， and in the elimination of unwanted proteinase activity in food processes. Proteinase inhibitors are also useful biochemical tools for studying proteinase classes and specificities. This article discusses how proteinase inhibition is involved in some processes of current interest to food scientists and technologists. Enzymatic protein hydrolysis is a major concern for biological scientists. The hydrolysis of proteins is catalyzed by peptide-bond-splitting enzymes (Box 1). Proteinases and peptidases are involved in the hydrolysis of protein during digestion， and have important roles in physiology and pathology. Enzymatic protein hydrolysis is controlled in several ways， including by the use of specific inhibitors (Box 2). Proteinase inhibition is a common process in nature. Proteinase-inhibitor interactions are involved in protein digestion， various physiological processes (e.g. blood coagulation， fibrinolysis， complement activation and phagocytosis)， pathological processes (e.g. cancers and hypertension) and infection Another natural method of controlling proteinase activity is the synthesis of an inactive form of the enzyme， the zymogen. Zymogens are activated， usually by the action of another proteinase， in the digestive system and also during regulatory physiological processes. When an enzyme is in its active form， proteinase inhibition is an exquisite means of enzyme control in physiological processes， which is achieved by highly specific inhibitors. The importance of the control of proteolytic activity by inhibitors in physiological processes is demonstrated by the fact that inhibitor molecules exceed 10% of the total protein in human plasma. The fact that the control of proteolysis by inhibitors is so specific makes it a valuable tool in medicine， agriculture and food technology. The human immune deficiency virus proteinase， the digestive systems of crop pests， and fish muscle proteases are some examples of targets for study. Most organisms produce proteinase inhibitors as a means to control proteolytic processes.Some organisms store huge amounts of inhibitors， for example legume seeds and some leaves. This seems to be an evolutionary response to predation. Inhibitors for digestive proteinases in food and feed Some food ingredients contain so-called antinutritive factors: lectins， phenols， and other factors， including certain proteins that inhibit proteinases. The presence of proteinase inhibitors in living tissues seems to be a natural regulatory process 展开

化学专业英语翻译懂的翻译下谢谢: The X-ray diffraction (XRD) pattern was obtained on a Thermo ARL XTRA X-ray diffractometer with Cu K radiation ì 1.54178 Å). In situ XRD characterization was performed n a high-temperature attachment of the X-ray diffractometer. ... The X-ray diffraction (XRD) pattern was obtained on a Thermo ARL XTRA X-ray diffractometer with Cu K radiation ì 1.54178 Å). In situ XRD characterization was performed n a high-temperature attachment of the X-ray diffractometer. Transmission electron microscopy (TEM) observation was performed with a JEOL JEM 2010 high-resolution transmission electron microscope (HRTEM) operated at 200 kV. The UV vis diffuse reflectance spectrum (DRS) was obtained from a Perkin-Elmer Lambda 900 UV vis spectroscopy machine. The precursor was characterized by Fourier transform infrared (FT- R) spectroscopy on a Perkin-Elmer Spectrum One FT-IR machine by using the KBr pellets method. 展开

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