国产三级在线看完整版-内射白嫩大屁股在线播放91-欧美精品国产精品综合-国产精品视频网站一区-一二三四在线观看视频韩国-国产不卡国产不卡国产精品不卡-日本岛国一区二区三区四区-成年人免费在线看片网站-熟女少妇一区二区三区四区

儀器網(wǎng)(yiqi.com)歡迎您!

| 注冊(cè)2 登錄
網(wǎng)站首頁-資訊-話題-產(chǎn)品-評(píng)測(cè)-品牌庫-供應(yīng)商-展會(huì)-招標(biāo)-采購-知識(shí)-技術(shù)-社區(qū)-資料-方案-產(chǎn)品庫-視頻

問答社區(qū)

專業(yè)英語翻譯,急用

klm455403592 2011-05-09 17:15:02 575  瀏覽
  • This paper presents a procedure for preparing a nanofluid which is solid–liquid composite material consisting of solid nanoparticles with sizes typically of 1–100 nm suspended in liquid. By means of the procedure, Cu–H2O nanofluids with... This paper presents a procedure for preparing a nanofluid which is solid–liquid composite material consisting of solid nanoparticles with sizes typically of 1–100 nm suspended in liquid. By means of the procedure, Cu–H2O nanofluids with and without dispersant were prepared, whose sediment photographs and particle size distribution were given to illustrate the stability and evenness of suspension with dispersant. Aiming at the dispersion of nano-Cu is regarded as the guide of heat transfer enhancement, the dispersion behavior of Cu nanoparticles in water were studied under different pH values, different dispersant types and concentration by the method of zeta potential, absorbency and sedimentation photographs. The results show that zeta potential has good corresponding relation with absorbency, and the higher absolute value of zeta potential and the absorbency are, the better dispersion and stability in system is. The absolute value of zeta potential and the absorbency are higher at pH 9.5. Hexadecyl trimethyl ammonium bromide (CATB) and sodium dodecylbenzenesulfonate (SDBS) can significantly increase the absolute value of zeta potential of particle surfaces by electrostatic repulsions, and polyoxyethylene (10) nonyl phenyl ether (TX-10) can form a thick hydration layer on the particle surfaces by steric interference, which leads to the enhancement of the stability for Cu suspensions. In the 0.1% copper nano-suspensions, the optimizing concentrations for TX-10, CATB, and SDBS are 0.43, 0.05, and 0.07%, respectively, which have the best dispersion results. . 2007 Elsevier Inc. All rights reserved. Keywords: Copper nano-suspensions; Dispersion and stability; Zeta potential; Absorbency 展開

參與評(píng)論

全部評(píng)論(2條)

  • 6762王_ 2011-05-15 00:00:00
    本文提出一種程序是準(zhǔn)備介紹固-液復(fù)合材料組成的納米粒子與固體的規(guī)格 通常的1海里懸浮在液體中。通過這一過程,Cu-H2O有和沒有nanofluids分散劑有準(zhǔn)備的 泥沙照片和粒度分布是說明穩(wěn)定性和均勻度的懸架分散劑。針對(duì) 在nano-Cu中的分散性的指南被視為傳熱的增強(qiáng)、分散行為的銅納米粒子在水處理 栽培條件下,研究了不同pH值、不同分散劑的類型和濃度的方法、吸濕性、泥沙淤積澤塔潛力 拍攝的照片。結(jié)果表明,具有良好的對(duì)應(yīng)關(guān)系,澤塔潛力與吸濕性、以及較高的值澤塔的潛力 和吸收性,更好的分散性和穩(wěn)定性在系統(tǒng)是。值的澤塔潛力和吸收性更高一點(diǎn) pH 9.5。三甲基溴化銨Hexadecyl CATB)和十二烷基苯磺酸鈉進(jìn)行(),可顯著提高 潛在的價(jià)值由澤塔瓊斯粒子表面靜電排斥作用造成,國際上(10)與苯醚(TX-10)能形成一個(gè)厚 在粒子表面保濕層由硬脂干擾,而導(dǎo)致的穩(wěn)定性增強(qiáng)銅停賽。在0.1% 銅nano-suspensions濃度為TX-10網(wǎng)絡(luò)的優(yōu)化,CATB 0.43,十二是,0.05,和0.07%,分別有 Z好的分散效果。 2007年農(nóng)業(yè)股份有限公司。保留所有權(quán)利。 關(guān)鍵詞:銅nano-suspensions;色散和穩(wěn)定性;澤塔潛能;吸光度的變化

    贊(15)

    回復(fù)(0)

    評(píng)論

  • 871087430 2011-05-10 00:00:00
    本文提出一個(gè)法制備納米流體程序,是固體液體固體顆粒復(fù)合材料組成與尺寸 通常在1-100納米懸浮液。通過對(duì)程序的方法,與不分散的Cu -水納米流體的制備,其 照片和泥沙粒徑分布說明了穩(wěn)定性和懸浮與分散均勻度。針對(duì) 在納米銅分散是作為強(qiáng)化傳熱導(dǎo)認(rèn)為,銅納米粒子分散在水中的行為 在不同的pH值,分散劑種類和濃度不同,研究由Zeta電位,吸光度和沉淀法 照片。結(jié)果表明,zeta電位,具有良好的吸水性的對(duì)應(yīng)關(guān)系,具有較高的zeta電位值 與吸光度,更好的分散和系統(tǒng)的穩(wěn)定性。 Zeta電位的值與吸光度較高, pH值9.5。十六烷基三甲基溴化銨(CATB)和十二烷基苯磺酸鈉(SDBS的)可以顯著提高 顆粒表面的zeta電位的靜電排斥力,和聚氧乙烯(10)壬苯基醚(的TX - 10)的值可以形成厚 水化顆粒層表面上的空間位阻干擾,從而導(dǎo)致對(duì)銅懸浮液的穩(wěn)定性增強(qiáng)。在0.1% 銅納米懸浮液,為TX - 10,CATB濃度的優(yōu)化,和SDBS是0.43,0.05,和0.07%,分別有哪些 Z佳分散效果。 。 2007年愛思唯爾公司保留所有權(quán)利。 關(guān)鍵詞:銅納米懸浮液,分散和穩(wěn)定; Zeta電位;吸水性 朗讀 顯示對(duì)應(yīng)的拉丁字符的拼音字典

    贊(10)

    回復(fù)(0)

    評(píng)論

熱門問答

專業(yè)英語翻譯,急用
This paper presents a procedure for preparing a nanofluid which is solid–liquid composite material consisting of solid nanoparticles with sizes typically of 1–100 nm suspended in liquid. By means of the procedure, Cu–H2O nanofluids with... This paper presents a procedure for preparing a nanofluid which is solid–liquid composite material consisting of solid nanoparticles with sizes typically of 1–100 nm suspended in liquid. By means of the procedure, Cu–H2O nanofluids with and without dispersant were prepared, whose sediment photographs and particle size distribution were given to illustrate the stability and evenness of suspension with dispersant. Aiming at the dispersion of nano-Cu is regarded as the guide of heat transfer enhancement, the dispersion behavior of Cu nanoparticles in water were studied under different pH values, different dispersant types and concentration by the method of zeta potential, absorbency and sedimentation photographs. The results show that zeta potential has good corresponding relation with absorbency, and the higher absolute value of zeta potential and the absorbency are, the better dispersion and stability in system is. The absolute value of zeta potential and the absorbency are higher at pH 9.5. Hexadecyl trimethyl ammonium bromide (CATB) and sodium dodecylbenzenesulfonate (SDBS) can significantly increase the absolute value of zeta potential of particle surfaces by electrostatic repulsions, and polyoxyethylene (10) nonyl phenyl ether (TX-10) can form a thick hydration layer on the particle surfaces by steric interference, which leads to the enhancement of the stability for Cu suspensions. In the 0.1% copper nano-suspensions, the optimizing concentrations for TX-10, CATB, and SDBS are 0.43, 0.05, and 0.07%, respectively, which have the best dispersion results. . 2007 Elsevier Inc. All rights reserved. Keywords: Copper nano-suspensions; Dispersion and stability; Zeta potential; Absorbency 展開
2011-05-09 17:15:02 575 2
應(yīng)用化學(xué)專業(yè)英語翻譯
Herein, we present a template approach that allows for the incorporation of normally labile metal centers, such as copper(I), copper(II), and silver(I), into DNA branch points(Scheme 1 a). Remarkably high structural stability and chir-al... Herein, we present a template approach that allows for the incorporation of normally labile metal centers, such as copper(I), copper(II), and silver(I), into DNA branch points(Scheme 1 a). Remarkably high structural stability and chir-ality transfer to the metal complex are demonstrated. More-over, we have used this approach to generate the first example of a dynamic multimetallic metal–DNA assembly, with three metal complexes as the corners, single-stranded DNA as the sides, and multiple DNA double strands at the periphery (Scheme 1 d). We demonstrate quantitative and reversible structural switching of these metal–DNA nanostructures by adding specific DNA strands, resulting in controlled modu-lation of the metal–metal distances.This contribution thus allows the programmable generation of structurally dynamic multimetallic metal–DNA assemblies, with anticipated appli-cations in nanoelectronics, nanooptics, artificial photosyn-thesis, high-density data storage, and catalysis. To create stable and electroactive metal–DNA junctions,we examined the attachment of the ligand bis(2,9-diphenyl)-1,10-phenanthroline (dpp) to DNA (Scheme 1 a). This ligand has been used by the groups of Sauvage and others to generate interwoven structures.[10]It forms complexes such as [Cu(dpp)2]+, whose redox potential falls within the compat-ible window for DNA bases (+ 0.8 to-0.7V vs. saturated calomel electrode, SCE) 展開
2013-05-02 09:56:40 546 1
化學(xué)專業(yè)英語翻譯
以Na2WO4.2H2O和Zn(NO3)2.6H2O為原料,采用水熱法制備出ZnWO4納米晶催化劑。以曙紅B為目標(biāo)降解物,研究了ZnWO4催化劑的光催化性能,探討了水熱溫度、水熱時(shí)間和水熱溶液pH值對(duì)ZnWO4催化劑的結(jié)晶形態(tài)及光催化活性的影響規(guī)律,結(jié)果表明:在酸性條件下制備的ZnWO4為片... 以Na2WO4.2H2O和Zn(NO3)2.6H2O為原料,采用水熱法制備出ZnWO4納米晶催化劑。以曙紅B為目標(biāo)降解物,研究了ZnWO4催化劑的光催化性能,探討了水熱溫度、水熱時(shí)間和水熱溶液pH值對(duì)ZnWO4催化劑的結(jié)晶形態(tài)及光催化活性的影響規(guī)律,結(jié)果表明:在酸性條件下制備的ZnWO4為片狀結(jié)構(gòu),鏈狀分布,而在堿性條件下為棒狀結(jié)構(gòu)。在180℃,24 h的制備條件下,ZnWO4催化劑顯示出Z高的光催化活性。水熱溶液pH=5和pH=8時(shí)制得的催化劑在2 h內(nèi)對(duì)5 mg/L的曙紅B溶液的脫色率分別達(dá)到86%和95%。制備過程中溶液的pH值,催化劑的晶態(tài)和比表面積是影響催化劑活性的重要因素。 展開
2011-01-01 00:21:43 445 3
化學(xué)專業(yè)英語翻譯 不要翻譯工具
D,L252單取代海因是工業(yè)生產(chǎn)D2氨基酸的重要前體[1~3]。海因酶具有底物特異性,D2海因酶(EC3151212)可轉(zhuǎn)化外消旋的D,L252單取代海因中的D型消旋體成為D2N2氨甲酰氨基酸,剩余的L252單取... D ,L252單取代海因是工業(yè)生產(chǎn) D2氨基酸的重要前體[1~3 ]。海因酶具有底物特異性 ,D2海因酶(EC 3151212)可轉(zhuǎn)化外消旋的D ,L252單取代海因中的D型消旋體成為D2N2氨甲酰氨基酸 ,剩余的L252單取代海因由于完全不被 D2海因酶所作用 ,如圖 1所示 ,先進(jìn)行消旋 ,從而使得 D ,L2海因完全轉(zhuǎn)化為光學(xué)純的 D2N2氨甲酰氨基酸 ,并進(jìn)一步被轉(zhuǎn)化為D2氨基酸。因此 ,52單取代海因的自發(fā)消旋成為L2或D2N2氨甲酰氨基酸生產(chǎn)中的一個(gè)重要的步驟。若海因的自發(fā)消旋速率遠(yuǎn)低于海因水解酶的水解速率 ,則海因的消旋將成為D2N2氨甲酰氨基酸生產(chǎn)中的一個(gè)限速步驟。目前關(guān)于 52單取代海因的消旋的文獻(xiàn)非常少 ,海因消旋的細(xì)節(jié)問題也沒有被完全揭示。 1 材料與方法 111 實(shí)驗(yàn)材料 L2丙氨酸(國家生化工程ZX) 、 L2苯丙氨酸(國家生化工程ZX) 、氰酸鈉(江都化工廠) ,其他試劑為國產(chǎn)分析純?cè)噭?112 實(shí)驗(yàn)方法 11211 52取代海因衍生物的制備 采用Henze2Speer法[4~5 ]進(jìn)行52取代海因衍生物的制備: 反應(yīng)溫度為60~80 ℃。反應(yīng)6 h后 ,加入鹽酸酸化 ,繼續(xù)加熱 8 h ,冷卻后過濾得到的固體用酒精和水的混合溶液重結(jié)晶 ,得到無色晶狀目的產(chǎn)物。因使用的氨基酸不同 ,反應(yīng)條件略有變化 ,產(chǎn)率一般為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.精確稱量41000 g L252甲基海因 ,溶解于蒸餾水中 ,定容至250 mL ,測(cè)定其旋光度 ,并以此值為未消旋化的起始數(shù)據(jù)。 b.用 6 mol/ L 的 NaOH溶液調(diào)整海因溶液 pH值達(dá)810 ,90 ℃水浴2 h ,于旋光儀上測(cè)定其旋光度。 c.同 b ,依次調(diào)節(jié)溶液pH值為710、 810、 910 ,分別測(cè)定其旋光度。 d.同 b ,依次于50 ℃水浴中及室溫下恒溫2 h ,分別測(cè)定其旋光度 ,并與起始數(shù)據(jù)對(duì)比 ,計(jì)算消旋比 r ( %) :r =αt/α0 ,其中αt 為 t 時(shí)間溶液的旋光度 ,α0為溶液初始旋光度。 11213 海因的堿解 精確稱量41000 g L252甲基海因 ,溶解于蒸餾水中 ,定容至 250 mL ,用 NaOH溶液和鹽酸分別調(diào)至pH = 2、 8、 12 , 90 ℃水浴反應(yīng)4 h ,中間取樣測(cè)定其N2氨甲酰丙氨酸濃度。 11214 海因的轉(zhuǎn)化 采用012 %的海因溶液 ,按 w (底物)∶ w (菌泥)= 1∶ 5的比例 ,于pH 915 ,溫度40 ℃下進(jìn)行轉(zhuǎn)化。 取樣:取樣10 mL ,加入 5 mL 三停止反應(yīng) ,搖勻 ,放冰箱待測(cè)。 3 結(jié) 論 311 海因的消旋遵循本文所提出的碳負(fù)離子理論 ,其消旋過程為一級(jí)反應(yīng)動(dòng)力學(xué)過程。由海因消旋的半衰期可看出提高溫度和pH對(duì)海因的消旋均有利 ,但pH過高的情況下海因則會(huì)發(fā)生堿解反應(yīng)從而造成損失。 312 本文采用的海因轉(zhuǎn)化酶系中所含為 D2海因酶 ,對(duì)D2海因的轉(zhuǎn)化活性非常高 ,由此可見 ,如若采用的轉(zhuǎn)化體系中沒有消旋酶的存在 ,則海因的消旋成為海因酶轉(zhuǎn)化生產(chǎn)光學(xué)活性氨基酸的一個(gè)限速步驟。 展開
2009-06-08 13:22:45 706 3
化學(xué)專業(yè)英語翻譯 懂的翻譯下 謝謝
The X-ray diffraction (XRD) pattern was obtained on a Thermo ARL XTRA X-ray diffractometer with Cu K radiation ì 1.54178 ?). 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 ?). 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. 展開
2010-03-07 19:15:29 632 2
高分求 光學(xué)薄膜 物理 專業(yè)英語翻譯 有追加
翻譯 論文摘要 給出了部分關(guān)鍵詞 希望對(duì)你您有所幫助 也希望您對(duì)我有所幫助 呵呵 部分關(guān)鍵字: 帶通濾光片 近紅外 膜系設(shè)計(jì) 短波通 ZX波長 透射率 key words :pass-band optical filter; near infrared; film system design;short wave pass;centr... 翻譯 論文摘要 給出了部分關(guān)鍵詞 希望對(duì)你您有所幫助 也希望您對(duì)我有所幫助 呵呵 部分關(guān)鍵字: 帶通濾光片 近紅外 膜系設(shè)計(jì) 短波通 ZX波長 透射率 key words :pass-band optical filter; near infrared; film system design;short wave pass;central wavelength ;transmittance 翻譯正文如下: 摘要:隨著礦難的頻頻發(fā)生,瓦斯探測(cè)器的靈敏度越來越受到人們重視。 本文中的紅外吸收型甲烷檢測(cè)儀便具有選擇性強(qiáng),靈敏度高等優(yōu)點(diǎn)。其中近紅外濾光片為該裝置的核心部件。 本文介紹了利用特征矩陣法進(jìn)行薄膜設(shè)計(jì)的制作方法。 采用Si和SiO2作為薄膜材料,利用ZX波長不同的長波通和短波通濾光片對(duì)接,以完成近紅外波段的帶通濾光片設(shè)計(jì)。 該濾光片ZX波長為1651nm,并在該波長附近的透射率可達(dá)到95%。 能翻多少翻多少 一句也行呀 呵呵 google的就免了,翻得好有追加,人格擔(dān)保~~ 展開
2010-06-02 04:05:57 601 5
英語翻譯
UNIPHOS-400 multiparameter UV/IR based Fire Detector detects fire by detecting simultaneously three important characteristics of fire viz. UV radiation in the solar blind region of 185-260 nm, IR emission from the hot CO2 which invariab... UNIPHOS-400 multiparameter UV/IR based Fire Detector detects fire by detecting simultaneously three important characteristics of fire viz. UV radiation in the solar blind region of 185-260 nm, IR emission from the hot CO2 which invariably is present in and around a fire and the continuum black body IR radiation from the fire. This microprocessor based detector is housed in a flameproof enclosure with a viewing window. It is mounted on a wall mountable stand with provision to adjust the field of view to bring the viewing window in line of sight of the likely spot where fire can occur. The detector gives a fire alarm (red led glows) when all the three chosen fire parameters are detected. Simultaneously a relay output is available. When any one of IR or UV radiation is detected yellow led glows to give a warn alarm and also a relay output is available. The detector also provides an analog 4-20mA output and a RS485 digital output to indicate the above events. 展開
2015-08-16 09:24:04 444 3
英語翻譯
Forexample,intest,measurement,andcontrol,engineershaveusedvirtualinstrumentationtodownsizeautomatedtestequipment(ATE)whileexperiencinguptoa10timesincreaseinproductivityga... For example, in test, measurement, and control, engineers have used virtual instrumentation to downsize automated test equipment (ATE) while experiencing up to a 10 times increase in productivity gains at a fraction of the cost of traditional instrument solutions. Last year 25,000 companies in 90 countries invested in more than 6 million virtual instrumentation channels from National Instruments. 會(huì)的人幫忙翻譯一下,我翻譯的不通順,沒有中文的感覺。請(qǐng)高手幫助!菜鳥級(jí)別繞道。 展開
2013-02-17 07:55:07 589 4
英語翻譯,很專業(yè)的生物英語,翻譯器的不要,謝謝
Results:Membranefractionsfromthree-dayand200mMsalt-treatedArabidopsissuspensionplantswereisolated,followedbyproteaseshavingandenrichmentusingZirconiumion-chargedmagneticb... Results: Membrane fractions from three-day and 200 mM salt-treated Arabidopsis suspension plants were isolated, followed by protease shaving and enrichment using Zirconium ion-charged magnetic beads, and tandem mass spectrometry analyses. From this isolation, 18 phosphorylation sites from 15 Arabidopsis proteins were identified. A unique phosphorylation site in 14-3-3- interacting protein AHA1 was predominately identified in 200 mM salt-treated plants. We also identified some phosphorylation sites in aquaporins. A doubly phosphorylated peptide of PIP2;1 as well as a phosphopeptide containing a single phosphorylation site (Ser-283) and a phosphopeptide containing another site (Ser-286) of aquaporin PIP2;4 were identified respectively. These two sites appeared to be novel of which were not reported before. In addition, quantitative analyses of protein phosphorylation with either label-free or stable-isotope labeling were also employed in this study. The results indicated that level of phosphopeptides on five membrane proteins such as AHA1, STP1, Patellin-2, probable inactive receptor kinase (At3g02880), and probable purine permease 18 showed at least two-fold increase in comparison to control in response to 200 mM salt-stress. 展開
2011-06-07 04:07:51 589 3
材料專業(yè)英語翻譯(很短)(英譯中) 用翻譯軟件就免了25
7.2.4 Current Status of Sputtering Magnetron sputtering is the most widely used sputtering method and one of the wellestablished coating techniques used for microelectronic applications such as metallization and magnetic devices. In the ... 7.2.4 Current Status of Sputtering Magnetron sputtering is the most widely used sputtering method and one of the wellestablished coating techniques used for microelectronic applications such as metallization and magnetic devices. In the last several years, many nanometer multilayer structures based on different material systems and/or microstructures have been prepared by sputtering. However, the material systems are mainly limited to conductors and nitrides. Nevertheless, nanolayer BaTiO3 (Jia, et al., 1995a) and nanometer multilayer structures based on simple oxide materials such as Y2O3/ZeO2 superlattice (Yashar, et al., 1999) have been prepared by sputtering. 展開
2008-06-11 15:41:09 615 1
英語翻譯求助
The scheduler function involves planning how to produce the current volume of orders in the FMS, considering the current status of machine tools, work-in-process, tooling, fixtures, and so on. [91 The scheduling can be done automatically or... The scheduler function involves planning how to produce the current volume of orders in the FMS, considering the current status of machine tools, work-in-process, tooling, fixtures, and so on. [91 The scheduling can be done automatically or can be assisted by an operator. Most FMS control systems combine automatic and manual scheduling; the system generates an initial schedule that can be changed manually by the operator. The dispatcher function involves carrying out the schedule and coordinating the activities on the shop floor, that is, deciding when and where to transport a pallet, when to start a process on a machining center, and so on. The monitor function is concerned with monitoring work progress, machine status, alarm messages, and so on, and providing input to the scheduler and dispatcher as well as generating various production reports and alarm messages. A transport control module manages the transportation of parts and palettes within the system. Having an AGV system with multiple vehicles, the routing control logic can become rather sophisticated and become a critical part of the FMS control software. A load/unload module with a terminal at the loading area shows the operators which parts to introduce to the system and enables him or her to update the status of the control system when parts are3. Materials Handling System The automated materials handling system is a fundamental component that helps mold a group of independent CNC machines into a comprehensive FMS. The system must be capable of accepting workpieces mounted on pallets and moving them from workstation to workstation as needed. It must also be able to place workpieces on hold as they wait to be processed at a given workstation. The materials handling system must be able to unload a workpiece at one station and load another for transport to the next station. It must accommodate computer control and be completely compatible with other components in the flexible manufacturing system. Finally, the materials handling system for an FMS must be able to withstand the rigors of a shop environment. Some FMSes are configured with automated guided vehicles (AGVs) as a principal means of materials handling. 展開
2009-03-31 17:58:44 558 1
跪求英語翻譯。
Experiment SiO2 films with a thickness of 300 nm were grown on (100) p-Si substrates, with a resistivity of 4 W cm, using thermal oxidation at 1,000 C, for 90 min. Monte Carlo simulationcode (TRIM) was used to calculate the adequate ene... Experiment SiO2 films with a thickness of 300 nm were grown on (100) p-Si substrates, with a resistivity of 4 W cm, using thermal oxidation at 1,000 C, for 90 min. Monte Carlo simulationcode (TRIM) was used to calculate the adequate energy in order to place the maximum Ge concentration at the middle of the SiO2 film. SiO2 matrices were implanted with Ge74+ ions at RT, with 250 keV energy, using implantation doses of [0.5, 0.8, 1, 2, 3 and 4] · 1016 cm–2. After ion implantation, the samples were annealed at 1,000 C for 1 h in a forming gas atmosphere to precipitate Ge and to form the nanocrystallites. Raman spectra were obtained using a triple grating T- 64000 Jobin-Yvon spectrometer, with 1 cm–1 spectral resolution. The 514 nm line of the argon laser was used to excite the samples. All samples were measured at RT; the laser power on the sample was 9 mW. The diameter of the laser spot was 50 lm and the integration time was 30 min. The resonant Raman spectra were obtained in the backscattering configuration. The orientation of the Si substrate is fundamental to polarize the laser light, allowing the second-order Raman Si peak, at about 300 cm–1, to be suppressed not masking the Raman peaks corresponding to Ge-nc. PL spectra were measured at RT with a 240 nm excitation source, using a Spex Fluoromax spectrometer with a R298 Hamamatsu photomultiplier. Compositional analysis of the SiO2 matrix was carried out using a DIGILAB infra-red Fourier transform spectrometer. The system was purged with dry N2 to reduce the infrared (IR) absorption from H2O and CO2. Transmittance measurements were carried out within the 400– 4,000 cm–1 range at 300 K. The beam spot size was about 5 mm diameter and the resolution was 4 cm–1. In all cases a non-processed Si substrate sample was used as a reference. Results and discussions Figure 1 presents the Raman spectra of the films implanted with various doses [0.5; 0.8; 1; 2; 3; 4] · 1016 cm–2, followed by annealing forming-gas, (92% N2 + 8% H2) at 1,000 C, for 1 h. The position of the peak for bulk Ge was determined at 302.4 cm–1 and this value is used to compare with Ge-nc peaks. The Raman spectra of the implanted samples clearly show three bands: 210–280, 304 and 430 cm–1. The first one, 210–280 cm–1, is associated with amorphous Ge compounds. Such band was expected as the samples have been annealed at 1,000 C, therefore above the Ge melting temperature (938.3 C) [10]. At this temperature, Ge precipitates as liquid droplets inside a viscous oxide matrix. The second band was near 304 cm–1, and can be associated with Ge-nc. This band is in good agreement with the work reported by Wu et al. [11]. Finally, the third band at 430 cm–1 is related to local Si–Si vibrations [12]. 展開
2018-12-06 19:16:01 390 0
科技英語翻譯
哪位高手幫忙翻譯一下,非常感謝?。?! Casted titanium for dental crowns has been investigated by means of X-ray Photoelectron Spectroscopy (XPS), X-Ray Di?raction (XRD) and Scanning Electron Microscopy (SEM). The samples were prepare... 哪位高手幫忙翻譯一下,非常感謝?。。?Casted titanium for dental crowns has been investigated by means of X-ray Photoelectron Spectroscopy (XPS), X-Ray Di?raction (XRD) and Scanning Electron Microscopy (SEM). The samples were prepared according to the Ohara process. XRD analysis revealed that the investment consisted essentially of SiO2, Mg2P2O7, SiO2?H2O and Mg2SiO4. SEM experiments combined with EDX analysis revealed the following atomic concentrations Si (62.6%), Mg (19.7%), P (17.1%), and Ca (0.6%). After casting, the titanium samples exhibit a rough and irregular surface, and XRD analysis indicated that titanium contains essentially the α phase and traces of the β phase. After demoulding titanium samples, the investment side which was in contact with titanium was black colored, proving the reaction between titanium and the investment. XPS analysis performed on this side of the investment indicated that the Si 2p peak presents a shoulder on the low binding energy side and thus suggest that SiO2 has been transformed into metallic Si. 展開
2018-11-19 21:52:36 362 0
英語翻譯(2)
Keywords:Epoxides;Amines;2-Aminoalcohols;Yttriumnitratehexahydrate;RegioselectivityAminoalcoholsconstituteanimportantclassofcompoundshavingbothchemicalandbiologicalapplic... Keywords: Epoxides; Amines; 2-Amino alcohols; Yttrium nitrate hexahydrate; Regioselectivity Amino alcohols constitute an important class of compoundshaving both chemical and biological applications. They are important pharmacophores present in various inhibitors and are used as building blocks for the synthesis of biologically active natural products, insecticidal agents and chiral auxillaries for asymmetric reactions.1a–f They act as starting materials for the synthesis of oxazolines which are useful in the polymer industry.1g Owing to their widespread applications, the synthesis of amino alcohols has received much attention in recent years. Traditionally, 2-amino alcohols are prepared by heating an epoxide with an excess of amine at elevated temperature. The use of a high temperature leads to undesired side reactions and also limits the applicability towards temperature sensitive substrates. To overcome these drawbacks various promoters such as ZnCl2,2 ScOTf,3 MgBr2OEt2,4 67 9 bismuth salts,5 CoCl2, CuBF4, DIPAT,8 Ti(OiPr)4, 1011 12TaCl5, ZrCl4, Sm(OTf)3, potassium dodecatungstocobaltate, 13 and aluminosilicate14 have been employed for the above transformation. The use of non-conventional techniques such as microwave irradiation at elevated temperaturehas also been reported.15 Recently, the use of Al(OTf)3 (1 mol %) as catalyst in toluene at reflux has also been reported.16 Although significant advances have been made in this area, low regioselectivity, longer reaction time, use of elevated temperature, high catalyst loading, toxic solvents and lower substrate compatibilitylimit their applications.Thus there is a need to develop an efficient catalytic protocol for ring opening of various epoxides with aliphatic, aromatic andheteroaromatic amines under ambient conditions 展開
2008-05-21 01:00:39 366 3
藥學(xué)英語翻譯
Havingbrieflyexaminedthestructureoforganicpackingsandthevariousroutesintheirmanufacture,themostimportantfeaturesmaybesummarizedasfollows:>Hydrophilicaswellaslipophilicorg... Having briefly examined the structure of organic packings and the various routes in their manufacture, the most important features may be summarized as follows: > Hydrophilic as well as lipophilic organic packings are synthesized with a controlled pore and surface structure depending on the type of monomer/comonomer and the polymerization reaction. Surface structure can be altered by controlled consecutive surface reactions. > In accordance with the bulk composition, polymer packings are stable across almost the entire pH range, particularly under strong alkaline conditions. > Chemical stability is affected by oxidizing and reducing solutions. > Although cross-linking reactions have been optimised in as much as rigid pressure stable particles can be manufactured, some remaining swelling property is often noted when changing the solvent composition in HPLC. > As in the manufacture of silica, porosity, pore size, and surface area of polymer packings can be adjusted over a wide range, and micro-, meso-, and macro- as well as non-porous beads are synthesized reproducibly. 3.2.4.2 Hydrophobic Polymer Stationary Phases The synthesis of cross-linked copolymers of styrene and divinylbenzene has been studied intensively and is well documented. The starting monomer is styrene, and divinylbenzene (DVB) is used as cross-linker. The amount of DVB can reach up to 55wt.%. At 55% DVB, the copolymer shows practically no swelling and possesses a permanent porosity. Figure 3.21 illustrates the network structure of poly(styrenedivinylbenzene) (St-DVB). Commercial products differ in bead size and pore size. There are even non-porous products on the market, designed for the rapid separation of peptides and proteins by reversed phase HPLC (Maa and Horvath, 1988). St-DVB copolymers are stable in the pH range 0–14. They find increasing application in the separation of low molecular weight compounds, peptides, and proteins by means of reversed phase chromatography (Tanaka et al., 1987, Tweeten and Tweeten, 1986) and as parent materials for the synthesis of derivatized packings in interaction chromatography of biopoly-mers (Unger et al., 1987, Regnier, 1987). Numerous other organophilic polymer packings have been synthesized for size exclusion and interactive HPLC after suitable derivatization. They are reviewed in depth by Mikes (1988). 展開
2010-11-30 04:37:20 445 2
機(jī)械英語翻譯網(wǎng)站
The varying rates of thermal expansion are the basis of the bimetal thermostat. The metal stripe of the thermostat have greatly different thermal expansion coefficients. When they are bonded together and heated, the metal with the high expa... The varying rates of thermal expansion are the basis of the bimetal thermostat. The metal stripe of the thermostat have greatly different thermal expansion coefficients. When they are bonded together and heated, the metal with the high expansion rate elongates much more than the other strip. This causes the strips to bend and touch the contact point. The lead screw goes through a pair of half nuts, which are fixed to the rear of the apron. When actuating a certain lever, the half nuts are clamped together and engage with the rotating lead screw as a single nut, which is fed, together with the carriage, along the bed. The width of cut is the width of the workpiece in contact with the cutter in a direction normal to the feed. We can easily see that the width of cut should decrease with increasing depth of cut to keep the load and power requirement below those that can be met by the cutter and the machine tool, respectively. The control unit coordinates the operations of all the other components. It controls the input and output information between the computer and the outside world through the I/O section, synchronizes the transfer of signals between the various sections of the computer, and commands the other sections in the performance of their functions. 展開
2008-12-12 12:48:55 514 3
機(jī)械加工設(shè)備怎么英語翻譯
 
2016-12-11 23:09:27 506 1
英語翻譯,急急!!在線等
光譜分析儀,拉力試驗(yàn)機(jī),動(dòng)平衡試驗(yàn)機(jī),金相顯微鏡,碳硫分析儀,沖天爐,地砂線,精密數(shù)控車床,精密數(shù)控磨床。翻譯成英語啊。在線等。非常急。非常感謝
2008-10-28 05:27:04 582 2
潛在蒸散定義,急用。。。。
 
2016-11-30 22:05:45 523 1

4月突出貢獻(xiàn)榜

推薦主頁

最新話題