化學(xué)專業(yè)英語
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10、TheuseofLewis-acidcatalystsinmodernorganichasbeenstudiedextensivelyduringthelastdecade.Nowadaystheresearchisfocusonthemoreversatile，moreselective，andmorereactivecatal... 10、The use of Lewis-acid catalysts in modern organic has been studied extensively during the last decade. Nowadays the research is focus on the more versatile， more selective， and more reactive catalyst. It has been found that gold Lewis acids are effective to catalyze the formation of C-C and oxidation reactions as the heterogeneous or the homogeneous catalysts. In particular， gold-catalyzed oxidation reactions have been applied in the epoxidation， oxidation of alcohols and aldehydes， and the oxidative cleavage of C-C double bonds. Sulfides oxidation is one of the most important organic processes， because the corresponding organosulfur compounds are versatile intermediates in organic synthesis and are useful for the preparation of biologically and medically important products. To the best knowledge， two examples of gold Lewis acid reveal the catalytic property in the reaction of sulfides to sulfoxides. 11、Anhydrous ethers is generally used as the solvent in the preparation of a Grignard reagent Actually， the ether plays a more important role in the reaction than merely that of solvent. Ether molecules combine with the various components of a Grignard reagent to form complex etherates. For example， one of the components in phenyl magnesium bromide-ether solution is a complex. 展開
全部評論(5條)
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- CAROLS01 2008-06-11 00:00:00
- （樓主好，不好意思，我這一會兒有點(diǎn)久，我是二樓的回答者elinwf，因?yàn)槿龢墙栌昧宋曳g的前一部分，所以我不得不重新借別人的號來回答剩下的部分，以免引起誤會，希望我的翻譯能讓你滿意） 因?yàn)橄鄳?yīng)的有機(jī)硫混合物是有機(jī)合成的通用中間體，并且廣泛用于制備重要的生物和醫(yī)學(xué)產(chǎn)品。據(jù)悉，含金路易斯酸催化劑的催化反應(yīng)實(shí)例表明了它在硫化物反應(yīng)生成亞砜過程中的催化特性。 11、一般認(rèn)為在格林試劑的制備過程中無水僅是作為溶劑，事實(shí)上，并非僅僅作為溶劑，而是起著非常重要的作用。分子與大量格林試劑分子締合形成復(fù)雜的絡(luò)合物。舉例來說，苯基鎂溴化醚溶液中的一個(gè)組成就是一個(gè)復(fù)合體。
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- awardui 2008-06-12 00:00:00
- 翻譯： 過去的一段時(shí)間，人們已經(jīng)廣泛的研究了路易斯酸催化劑在現(xiàn)代有機(jī)化學(xué)中的應(yīng)用。目前的研究集中在找到通用性更強(qiáng)、選擇性和催化活性更高的催化劑。研究發(fā)現(xiàn)用含金的劉易斯酸作為均相和非均相催化劑催化C-C結(jié)構(gòu)的形成和氧化反應(yīng)效果很好。特別是金元素催化已經(jīng)被應(yīng)用于某些反應(yīng)：環(huán)氧化作用、醇和醛的氧化、C-C雙鍵的氧化斷裂。硫化物的氧化是Z重要的氧化反應(yīng)之一，因?yàn)橄鄳?yīng)的有機(jī)硫化合物是多種多樣中間體在有機(jī)合成中非常有用在制備生物和醫(yī)學(xué)的重要產(chǎn)品的過程中。權(quán)威知識表明，比如黃金Lewis酸揭示催化性，在反應(yīng)的硫化物催化可以得到亞砜。 11.無水醚一般為溶劑，在一些格氏試劑中，在各種反應(yīng)溶劑中發(fā)揮著越來越重要的作用的。甲醚的分子結(jié)合起來，與各組成部分的格氏試劑，形成復(fù)雜的化合無 。舉例來說，一個(gè)組成部分，在苯基溴化鎂醚的合成中是復(fù)合合成物。 可能還是不專業(yè)，專業(yè)的東西很多，不能用普通的英語思維去翻譯了。
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- 逆轉(zhuǎn)駕到 2008-06-11 00:00:00
- 在過去的十年中，人們已經(jīng)廣泛的研究了路易斯酸催化劑在現(xiàn)代有機(jī)化學(xué)中的應(yīng)用。目前的研究集中在找到通用性更強(qiáng)、選擇性和催化活性更高的催化劑。研究發(fā)現(xiàn)用含金的劉易斯酸作為均相和非均相催化劑催化C-C結(jié)構(gòu)的形成和氧化反應(yīng)效果很好。特別是金元素催化已經(jīng)被應(yīng)用于某些反應(yīng)：環(huán)氧化作用、醇和醛的氧化、C-C雙鍵的氧化斷裂。硫化物的氧化是Z重要的氧化反應(yīng)之一，因?yàn)? 有點(diǎn)事，過會兒再翻，上面的可以放心用
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- el3pl5 2008-06-11 00:00:00
- 10 ，使用路易斯酸催化劑在現(xiàn)代有機(jī)已被廣泛的研究在過去十年期間?，F(xiàn)在的研究是著眼于更靈活，更有選擇性，更反應(yīng)的催化劑。它已發(fā)現(xiàn)，黃金路易斯酸是有效的催化形成對CC和氧化反應(yīng)，作為非均質(zhì)，或均相催化劑。特別是，黃金催化氧化反應(yīng)，已適用于環(huán)氧化，氧化醇類和醛類化合物，以及氧化裂解消委會雙鍵。硫化物的氧化是其中Z重要的有機(jī)過程，因?yàn)橄鄳?yīng)的有機(jī)硫化合物是多才多藝的中間體在有機(jī)合成中和非常有用的制備生物和醫(yī)學(xué)的重要產(chǎn)品。以Z好的知識，這兩個(gè)例子，黃金Lewis酸揭示催化性能，在反應(yīng)的硫化物，以亞砜。 11 ，無水醚是一般用于為溶劑，在編寫一格氏試劑其實(shí)，中發(fā)揮著越來越重要的作用的反應(yīng)比只是溶劑。甲醚的分子結(jié)合起來，與各組成部分的格氏試劑，形成復(fù)雜的etherates 。舉例來說，一個(gè)組成部分，在苯基溴化鎂醚的解決方案是一項(xiàng)復(fù)雜的。
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- yyb731216 2016-08-30 00:00:00
- 過去十年里曾仔細(xì)研究過把路易斯酸作為有機(jī)反應(yīng)的催化劑。現(xiàn)在這一研究轉(zhuǎn)向研究更全面、更有選擇性和活性更強(qiáng)的催化劑上。尤其是把金作為催化劑應(yīng)用于環(huán)催化、醇酮催化氧化和碳碳雙鍵的氧化裂解上。硫化物氧化是Z重要的有機(jī)過程之一，因?yàn)橛袡C(jī)硫化物是有機(jī)合成中運(yùn)用Z廣泛的中間體之一，在生化和醫(yī)藥制備中用途很廣。下面有兩個(gè)金作為路易斯酸的反應(yīng)的例子，它們可以說明硫化物轉(zhuǎn)變?yōu)閬嗧康姆磻?yīng)機(jī)理。 無水經(jīng)常作為制備格里雅試劑的溶劑。實(shí)際上，在反應(yīng)中的作用不僅僅是試劑。分子同格里雅試劑分子相連接形成一個(gè)復(fù)雜的醚和物。例如，在苯基溴化鎂和的溶液中就是如此。
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- 化學(xué)專業(yè)英語
- 10、TheuseofLewis-acidcatalystsinmodernorganichasbeenstudiedextensivelyduringthelastdecade.Nowadaystheresearchisfocusonthemoreversatile，moreselective，andmorereactivecatal... 10、The use of Lewis-acid catalysts in modern organic has been studied extensively during the last decade. Nowadays the research is focus on the more versatile， more selective， and more reactive catalyst. It has been found that gold Lewis acids are effective to catalyze the formation of C-C and oxidation reactions as the heterogeneous or the homogeneous catalysts. In particular， gold-catalyzed oxidation reactions have been applied in the epoxidation， oxidation of alcohols and aldehydes， and the oxidative cleavage of C-C double bonds. Sulfides oxidation is one of the most important organic processes， because the corresponding organosulfur compounds are versatile intermediates in organic synthesis and are useful for the preparation of biologically and medically important products. To the best knowledge， two examples of gold Lewis acid reveal the catalytic property in the reaction of sulfides to sulfoxides. 11、Anhydrous ethers is generally used as the solvent in the preparation of a Grignard reagent Actually， the ether plays a more important role in the reaction than merely that of solvent. Ether molecules combine with the various components of a Grignard reagent to form complex etherates. For example， one of the components in phenyl magnesium bromide-ether solution is a complex. 展開
2008-06-10 00:23:27
364
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- 化學(xué)專業(yè)英語·翻譯·謝\(^o^)/YES！
- Fig. 1 illustrates the microstructure and surface morphology of samples which include the bare substrate， the fluorinated with and without CeO2 thin film. Fig. 1a shows the initial surface state of the polished bare substrate. Some fine ste... Fig. 1 illustrates the microstructure and surface morphology of samples which include the bare substrate， the fluorinated with and without CeO2 thin film. Fig. 1a shows the initial surface state of the polished bare substrate. Some fine steaks resulting from the polishing progress are visible in the image. The surface is considerably rough and the activity of surface for magnesium alloy is various from sample to sample and within the same sample due to the presence of different phases [24，25]. In Fig. 1b， the micrograph was taken when the sample was fluorinated in the 20% HF for 20 h. There are a large number of pores and cracks on the surface of this sample; however， we cannot find the presence of remarked grinding scratches originated from the sample preparation on the surface in contrast with the bare substrate. It is well known that the magnesium alloy reacts with HF to form the fluoride coating via displacement reaction and the fluoride is insoluble， thus form a barrier on the surface of magnesium alloy. The pores and cracks distributed uneven also suggest that the activities on the surface of magnesium alloy are not very identical. The SEM image of the fluorinated sample with CeO2 thin film is shown in Fig. 1c. As can be seen from this image， most of the pores and cracks existed on the surface of the fluorinated sample have disappeared which is ascribed to the presence of CeO2 thin film. Moreover， the surface of CeO2 thin film is more uniform and more compact than that of the fluorinated sample， and this may explain why this kind of samples is the best corrosion resistant. XPS analysis is performed aiming at identifying the chemical composition of the film and the typical survey scan spectra are shown in Fig. 2. The main element peaks of Mg， C， O， F and Ce are shown in the spectra. A significant amount of carbon is present on the surface of the sample due to some contaminant that originates from the polishing， cleaning and heat-treatment procedure; moreover， there may be some remnant since the deficiently burning for celloidin during the heat-treatment. There are three peaks in the survey scan spectra as follows: Mg 2p3/2 at about 50 eV， Mg 2s at about 88 eV and Mg Auger peak at about 301 eV. The peak of Mg 2p around 50 eV is shown in Fig. 2 which reveals only one peak at 50.2 eV belonging to Mg 2p being the fingerprint for Mg2+ in the transitional region. Hence， it is most probable that the presence of Mg in the coating is a result of the formation of MgF2 in the course of the fluorinated process and the formation of MgO during the heat-treatment. Both the main components of O 1s peak located at 530.6 eV and the F 1s peak located at 684.7 eV give the evidence that the major states are MgO and MgF2. It is found that almost a pure Ce(IV) state in the spectrum of CeO2 and this is similar to these reported by ?koda et al. [26]. 展開
2009-03-30 12:58:40
424
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- 專業(yè)英語：force multiplication
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2008-09-17 07:10:12
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- 關(guān)于香水方面專業(yè)英語
- 索求香水方面專業(yè)術(shù)語：如噴頭pump， 蓋子cup等等，越多越來！本人傾私人“財(cái)產(chǎn)”報(bào)答之！
2008-10-29 19:30:18
742
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- 化工專業(yè)英語求翻譯
- Hollow polymeric spheres have been attracting increasing interest because of their potential applications， which range from targeted drug delivery to advanced functional materi- als.[1，2] Because of their hollow core structure， such poly... Hollow polymeric spheres have been attracting increasing interest because of their potential applications， which range from targeted drug delivery to advanced functional materi- als.[1，2] Because of their hollow core structure， such polymeric spheres can encapsulate large quantities of guest moleculesD especially those spheres with functionalities within the empty coreDand release them at a later stage in a controlled man- ner. Although hollow polymeric spheres with dimensions in the micrometer and submicrometer regions are readily con- structedDby layer-by-layer deposition of polyelectrolytes onto a template core，[3±6] polymerizing monomers in lipid vesi- cles，[7，8] emulsion polymerization，[9，10] pH-induced micelliza- tion of a grafted copolymer，[11] and by the assembly of posi- tively charged polyelectrolytes and negatively charged nanoparticles[12]Dthe synthesis of hollow spheres 100 nm or less in size has only recently become the subject of research activity. Several different routes， such as the self-assembly of block copolymers in a selective solvent，[13，14] the deposition of polyelectrolytes on a decomplexable or soluble core，[15，16] and microemulsion (as well as miniemulsion) polymerization，[17，18] have been developed to form hollow polymeric nanospheres. Although some of these methods have been quite successful， these strategies require the core templates to be removed in order to create a hollow interior， or need large quantities of surfactants to form nanosized micelles. Furthermore， although the majority of the proposed applications of hollow nano- spheres or nanocapsules are concentrated in the biomedical field， most of the hollow polymeric spheres described to date are ill-suited for such purposes. Therefore， materials (in par- ticular for the surfaces of the hollow nanospheres) that are biocompatible， non-toxic， and sometimes also biodegradable， are highly desirable. Herein， we demonstrate a simple and di- rect method for fabricating hollow polymeric nanospheres with biocompatible and biodegradable macromolecules. In this approach， hollow polymeric nanospheres were formed in a completely aqueous system without the aid of surfactants， 展開
2013-11-13 05:23:50
485
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- 金相試樣鑲嵌機(jī) 專業(yè)英語怎么說
2016-08-01 23:08:34
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- 【生物專業(yè)英語】摘要翻譯
- Abstract:Heavymetals，suchascadmium，copper，lead，chromiumandmercury，areimportantenvironmentalpollutants，particularlyinareaswithhighanthropogenicpressure.Theirpresenceinthea... Abstract: Heavy metals， such as cadmium， copper， lead， chromium and mercury， are important environmental pollutants， particularly in areas with high anthropogenic pressure. Their presence in the atmosphere， soil and water， even in traces can cause serious problems to all organisms， and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion， ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system， heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH， organic matter content， clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition， the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals， thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity. 用翻譯軟件的免回，哥也有，真誠求助高手！ 展開
2010-12-13 19:23:10
629
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- 麻煩幫我翻譯以下文章(生物專業(yè)英語)
- The most common means of agitation of liquid media is by placing the culture vessels on a drum(for test tubes)or a disk(for flasks)slowly rotating around a near horizontal axis. This assures good aeration of the liquid cultures with little... The most common means of agitation of liquid media is by placing the culture vessels on a drum(for test tubes)or a disk(for flasks)slowly rotating around a near horizontal axis. This assures good aeration of the liquid cultures with little mechanical damage to the cells.Agitation can also be achieved by placing culture flasks on reciprocating or gyrotory platform shakers.Gyrotoy (horizontal rotary orbit)shakers are preferred over reciprocating (horizontal linear motion)ones for a variety of reasons .The performance of the gyrotory shaker is determined by the speed of agitation and angle position of the flasks，with optimal aeration occurring in flasks tilted about 45° from the vertical.A new shaker design is the "tapping" motion shaker in which the culture is agitated by a magnetic bar moving up and down.This vertical movement of the bar is less injurious to cells than rotary movement of the bar at the bottom of the flask used in some conventional culture systems. 展開
2008-05-30 20:14:03
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2007-06-13 21:45:31
390
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- 請幫我翻譯一段專業(yè)英語吧。。急用。。多謝。。。
- Practical applications of colossal magnetoresistive(CMR) oxides are limited by the large magnetic fields and/or low temperature required to observe a significant change in electric resistivity[1-5]. In recent years，research on tunneling mag... Practical applications of colossal magnetoresistive(CMR) oxides are limited by the large magnetic fields and/or low temperature required to observe a significant change in electric resistivity[1-5]. In recent years，research on tunneling magnetoresistance(TMR) is a very active field because of its scientific interest and potential technological applications[6].Polycrystalline Sr2FeMoO6 perovskite is a candidate for magnetic sensors owing to its high ferromagnetic transition temperature …（Tc~420K）and the half-metallic electronic band structure predicted theoretically [7]. The conduction electrons in this compound are expected to be highly spin-polarized even at room temperature. More recently， perovskite Sr2FeMoO6 with nanometer grain size showed large magnetoresistance(~20%) at a low magnetic field of 4k Oe and at room temperature[8].Dai et al.[9]observed two different ordered structures in polycrystalline Sr2FeMoO6 perovskite: the double perovskite and the superstructure with tripled c-axis(ST).In this paper， another new layered structure of body-centered tetragonal phase (BT) is reported for the polycrystalline magnetoresistive Sr2FeMoO6 sample. Ceramic samples of Sr2FeMoO6 were prepared by standard solid state reaction. Stoichiometric materials of SrCO3，F(xiàn)e2O3 and MoO3 were mechanically mixed， and then calcined at 950℃ for 4h in air.The calcined mixture was then ball-milled and made into pellets followed by sintering at 1250℃for 4h in carbon monoxide atmosphere.Transmission electron microscopy(TEM) specimens were prepared by mechanical polishing，dimpling and ion milling.Electron diffraction patterns were taken at 120kV using a Phillips CM12 electron microscope， and high resolution TEM imaging was conducted using JEOL 2010 microscope. Energy dispersion of X-rays(EDX) was conducted by TEM attached with EDAX PV9100. 展開
2009-05-20 03:06:41
494
1
- 急求幫我翻譯一段電力專業(yè)英語文章?。?！
- What's therole of the Supercapacitor? The supercapacitor resembles a regular capacitorwith the exception that it offers very high capacitance in a small package.Energy storage is by means of static charge rather than of an electro-che... What's therole of the Supercapacitor? The supercapacitor resembles a regular capacitorwith the exception that it offers very high capacitance in a small package.Energy storage is by means of static charge rather than of an electro-chemicalprocess that is inherent to the battery. Applying a voltage differential on thepositive and negative plates charges the supercapacitor. This concept issimilar to an electrical charge that builds up when walking on a carpet. Thesupercapacitor concept has been around for a number of years. Newer designsallow higher capacities in a smaller size. Whereas a regular capacitor consists ofconductive foils and a dry separator， the supercapacitor crosses into batterytechnology by using special electrodes and some electrolyte. There are threetypes of electrode materials suitable for the supercapacitor. They are: highsurface area activated carbons， metal oxide and conducting polymers. The highsurface electrode material， also called Double Layer Capacitor (DLC)， is leastcostly to manufacture and is the most common. It stores the energy in thedouble layer formed near the carbon electrode surface. 展開
2013-06-11 09:00:02
513
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2018-01-06 13:14:33
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- 純水洗，我看到了pure laundering和washed pure哪個(gè)對啊？ 直噴水洗怎么翻譯呢？急求？謝謝~
2008-11-24 09:14:12
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- 誰能提供一些關(guān)于挖掘機(jī)，機(jī)~電~液 方面的專業(yè)術(shù)語英語， 要高端點(diǎn)的~太簡單的不要，太垃圾的不要越多越好~ （另有100分的追加）
2007-05-18 07:52:38
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- 因?yàn)槲覝?zhǔn)備從事電視機(jī)外銷的工作，但那些專業(yè)知識很缺乏。哪位好心人能幫幫忙，謝謝！
2006-12-23 04:51:54
444
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- 求求大哥大姐幫幫忙 幫小弟翻譯一下石油專業(yè)英語文章 急急急！
- An Ensemble Level Upscaling Approach for Efficient Estimation of Fine-Scale Production Statistics Using Coarse-Scale Simulations Yuguang Chen， SPE， Chevron Energy Technology Co.， and Louis J. Durlofsky， SPE， Stanford U. Copyright 2007， S... An Ensemble Level Upscaling Approach for Efficient Estimation of Fine-Scale Production Statistics Using Coarse-Scale Simulations Yuguang Chen， SPE， Chevron Energy Technology Co.， and Louis J. Durlofsky， SPE， Stanford U. Copyright 2007， Society of Petroleum Engineers This paper was prepared for presentation at the 2007 SPE Reservoir Simulation Symposium held in Houston， Texas， U.S.A.， 26–28 February 2007. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper， as presented， have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material， as presented， does not necessarily reflect any position of the Society of Petroleum Engineers， its officers， or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Electronic reproduction， distribution， or storage of any part of this paper for commercial purposes without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Write Librarian， SPE， P.O 展開
2009-12-28 03:58:03
639
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- 化學(xué)初中
- 鉻Cr與濃硫酸H?SO?反應(yīng)生成硫酸鉻Cr?（SO?）3二氧化碳和水怎么配平，說出思路
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