化学专业翻译2

whsxiaolong 2007-03-16 05:16:39 365 浏览

Summarizing the experimental data available today， thiol-capped CdTe nanocrystals synthesized in aqueous solution represent a kind of stable highly luminescent core-shell QD system with a naturally sulfur-capped surface (CdS shell) created ... Summarizing the experimental data available today， thiol-capped CdTe nanocrystals synthesized in aqueous solution represent a kind of stable highly luminescent core-shell QD system with a naturally sulfur-capped surface (CdS shell) created by mercapto- groups covalently attached to the surface cadmium atoms. All chemicals used were of analytical grade or of the highestpurity available. Al2Te3 (lumps) used as a source of H2Te waspurchased from CERAC Inc.， WI. Milli-Q water (Millipore)was used as a solvent. UV-vis absorption spectra were recorded with a Cary 50 spectrophotometer (Varian). Photoluminescence (PL) measurements were performed at room temperature using a FluoroMax-2 spectrofluorimeter (Instruments SA). The room-temperature PL quantum efficiency (QE) of CdTe nanocrystals was estimated following the procedure of ref 41 by comparison with Rhodamine 6G (laser grade， Lambda Physik) in ethanol (Uvasol) assuming its PL QE as 95%.42 High-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray analysis (EDX) were performed on a Philips CM-300 microscope operating at 300 kV. TEM samples were prepared by dropping diluted solutions of transferred in toluene (by surface exchange of capping agent with 1-dodecanethiol) CdTe nanocrystals onto 400-mesh carbon-coated copper grids with the excessive solvent immediately evaporated. Powder X-ray diffraction (XRD) measurements were carried out with a Philips X¢Pert diffractometer (Cu KR-radiation， variable entrance slit， Bragg-Brentano geometry， secondary monochromator). Samples for this study were prepared by placing finely dispersed powders of CdTe nanocrystals on standard Si supports. To investigate the photostability of CdTe QDs， dilute colloidal solutions were irradiated for different time intervals with light of a 450 W xenon lamp cut around 400 nm by a band-pass filter having a bandwidth of _40 nm and a peak transmission of _40%. a “Stable” means here that colloidal solutions of CdTe QDs are stable for months and even years being stored under air in the dark at room temperature. “Moderate” means that colloidal solutions coagulate occasionally during the storage; however， they are generally stable for months as well. Independent of the stabilizer nature， CdTe QDs are generally stable (no oxidation， no or only very minor changes of the optical properties) for years in powder form and in closely packed or nanocrystal/polymer films being kept in the dark under air. b The charge of nanocrystals was evaluated from ú-potential measurements with employment of oppositely charged latex beads. The experimental conditions were chosen so that the ú-potential of the beads changed its sign after adsorption of a monolayer of nanoparticles. 展开

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老末 2007-03-17 00:00:00

今对有效实验数据总结如下，水溶液中合成的硫醇包被碲化镉纳米晶代表着一种稳定、GX发光的壳－芯量子点体系，该体系带有和表面镉原子紧密结合的巯基官能团产生的硫化物自然包被表面(硫化镉外壳)。所有使用的化学品是分析纯或Z高纯度的。用来制备碲化氢的碲化铝购于CERAC公司，WI. Milli-Q水(Millipore公司)用作溶剂。紫外吸收光谱用Cary 50 分光光度计(Varian公司)记录。光致发光用FluoroMax-2 荧光分光光度计(Instruments SA公司)在室温下操作。碲化镉纳米晶在室温下的光致发光量子效率按照文献41中的步骤进行估计，该步骤中，用待测样和罗丹明6G (激光纯Lambda Physik公司)的乙醇(Uvasol公司)溶液进行比较，并假定后者的光致发光量子效率为95%（42）。高分辨率透射电镜和能量色散X射线分析用Philips CM-300型电镜在300 kV下操作。透射电镜样品用下述方法制备：碲化镉纳米晶转移到甲苯中配成稀释溶液(与包被剂1-十二烷基硫醇在表面进行交换)，然后滴加到 400目碳涂布的铜网上并立刻挥发去过量的溶剂。粉末X-射线衍射仪 were carried out with a Philips X¢Pert 散射仪(Cu KR-照射，可变光栅狭缝，Bragg-Brentano 几何仪，次级单色仪)。本研究使用的样品用分散良好的碲化镉纳米晶粉末置于标准硅支持体上的方法制备。为了研究碲化镉胶体量子点的光稳定性，稀释的胶体溶液用450 W的氙气灯发出的光在不同时间间隔进行照射，该光线在400 nm左右处被一个带宽40 nm和峰转移40%的窄带滤光片过滤。 A 这里的“稳定”指的是碲化镉胶体量子点的胶体溶液在室温下黑暗空气中储存几个月甚至几年是稳定的。“中等”指的是胶体溶液储存期间偶然发生凝固现象；然而，它们一般在几个月内是稳定的。不加稳定剂时密封包装或聚合物膜覆盖的碲化镉胶体量子点粉末在空气中几年内是稳定的(不被氧化，光学性质没有或者仅有微小变化)。 B 纳米晶体的电势用带有相反电荷液滴的ú-电位仪来估计。选择实验条件使得单层纳米颗粒吸收后液滴的ú-电位发生变化。

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化学专业翻译2: Summarizing the experimental data available today， thiol-capped CdTe nanocrystals synthesized in aqueous solution represent a kind of stable highly luminescent core-shell QD system with a naturally sulfur-capped surface (CdS shell) created ... Summarizing the experimental data available today， thiol-capped CdTe nanocrystals synthesized in aqueous solution represent a kind of stable highly luminescent core-shell QD system with a naturally sulfur-capped surface (CdS shell) created by mercapto- groups covalently attached to the surface cadmium atoms. All chemicals used were of analytical grade or of the highestpurity available. Al2Te3 (lumps) used as a source of H2Te waspurchased from CERAC Inc.， WI. Milli-Q water (Millipore)was used as a solvent. UV-vis absorption spectra were recorded with a Cary 50 spectrophotometer (Varian). Photoluminescence (PL) measurements were performed at room temperature using a FluoroMax-2 spectrofluorimeter (Instruments SA). The room-temperature PL quantum efficiency (QE) of CdTe nanocrystals was estimated following the procedure of ref 41 by comparison with Rhodamine 6G (laser grade， Lambda Physik) in ethanol (Uvasol) assuming its PL QE as 95%.42 High-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray analysis (EDX) were performed on a Philips CM-300 microscope operating at 300 kV. TEM samples were prepared by dropping diluted solutions of transferred in toluene (by surface exchange of capping agent with 1-dodecanethiol) CdTe nanocrystals onto 400-mesh carbon-coated copper grids with the excessive solvent immediately evaporated. Powder X-ray diffraction (XRD) measurements were carried out with a Philips X¢Pert diffractometer (Cu KR-radiation， variable entrance slit， Bragg-Brentano geometry， secondary monochromator). Samples for this study were prepared by placing finely dispersed powders of CdTe nanocrystals on standard Si supports. To investigate the photostability of CdTe QDs， dilute colloidal solutions were irradiated for different time intervals with light of a 450 W xenon lamp cut around 400 nm by a band-pass filter having a bandwidth of _40 nm and a peak transmission of _40%. a “Stable” means here that colloidal solutions of CdTe QDs are stable for months and even years being stored under air in the dark at room temperature. “Moderate” means that colloidal solutions coagulate occasionally during the storage; however， they are generally stable for months as well. Independent of the stabilizer nature， CdTe QDs are generally stable (no oxidation， no or only very minor changes of the optical properties) for years in powder form and in closely packed or nanocrystal/polymer films being kept in the dark under air. b The charge of nanocrystals was evaluated from ú-potential measurements with employment of oppositely charged latex beads. The experimental conditions were chosen so that the ú-potential of the beads changed its sign after adsorption of a monolayer of nanoparticles. 展开

求助化学专业翻译，谢谢: Syntheses and properties of fluorinated phosphate acrylates used for UV-curing coatings The acrylated perfluoroalkyl phosphates (PFPA I and PFPA II) used as an oligomer and monomer， respectively， for UV-curing systems were synthesized... Syntheses and properties of fluorinated phosphate acrylates used for UV-curing coatings The acrylated perfluoroalkyl phosphates (PFPA I and PFPA II) used as an oligomer and monomer， respectively， for UV-curing systems were synthesized and characterized with 1H NMR and FTIR spectra. The photopolymerization behavior was investigated by using photo-DSC analysis， showing that both acrylates were photopolymerized quickly to a moderate final unsaturation conversion at the presence of a photoinitiator. The limiting oxygen indices of the UV-cured pure filmswere determined to be over 35. The surface properties of UV-cured polyurethane films added PFPAs， respectively， as additives were investigated by measuring the contact angles. The results showed that the addition of a small amount of PFPA I or PFPA II efficiently led to the increases in the contact angles， and the decreases in the surface tension. The X-ray photoelectron spectroscopy analysis confirmed that the film surface was enriched with fluorinated species. 展开

专业翻译: Montmorillonite nanoparticles were found to be inefficient in polypropylene because of the lack of a heat insulating char layer and the decomposition of the couipatibilising surfactant layer on their surface.Comomation with an ammonium poly... Montmorillonite nanoparticles were found to be inefficient in polypropylene because of the lack of a heat insulating char layer and the decomposition of the couipatibilising surfactant layer on their surface.Comomation with an ammonium polyphosphatebased intumescent system shoued some synergism due to modified rheology.The effect of surface and interlace modification was analysed using Raman microscopy and X-ray photoelectron spectroscopy.Forming a heat resistant coating layer of low surface energy around the nanoparticles promotes their migration to the surface and formation of a flexible barrier layer， and thus leads to better performance. 展开

关于五金件表面处理PAINTING的专业翻译: 钣金机壳表面处理要求描述如下： PLATING. 1. ZINC PLATING PER ASTM-B633， TYPE 3， CLASS Fe-Zn13 2. CONVERSION COATING COLOR COLORLESS PER MIL-DTL-5541F TYPE II， CLASS 3， ROSH COMPLIANCE PAINTING. 1. PRIMER COATING EPOXY POL... 钣金机壳表面处理要求描述如下： PLATING. 1. ZINC PLATING PER ASTM-B633， TYPE 3， CLASS Fe-Zn13 2. CONVERSION COATING COLOR COLORLESS PER MIL-DTL-5541F TYPE II， CLASS 3， ROSH COMPLIANCE PAINTING. 1. PRIMER COATING EPOXY POLYAMIDE PER MIL-P-23377 TYPE 11， CLASS 1 2. TOP COATING EPOXY POLYAMIDE PER MIL-C-22750. COLOR RAL 7047 THICK. 20-30u. FINE TEXTURE. 请问， 1. 上面的英文描述的专业翻译是什么？ 2. ASTM-B633， TYPE 3， CLASS Fe-Zn13、 PER MIL-P-23377、MIL-C-22750和MIL-DTL-5541F TYPE II， CLASS 3， ROSH COMPLIANCE是什么标准吗？哪里有相关的资料？展开

尿维素C(VC干化学+2正常吗:

2，酶只能改变化学反应的活化能不能改变化学反:

中文翻译成英文，汽车变速器实验台使用说明.求专业翻译，谢绝机器翻译: diyi章操作说明一.实验台简介1.实验台示意图2.故障设置二．使用注意事项：1.380V三相电压是否安全，2，220v二相电压是否安全，2.安装蓄电池时必须注意正负极《220V变压12V.DC》，安装错... diyi章操作说明一.实验台简介 1.实验台示意图 2.故障设置二．使用注意事项： 1.380V三相电压是否安全， 2，220v二相电压是否安全， 2.安装蓄电池时必须注意正负极《220V变压12V.DC》，安装错误容易导致控制模块、传感器与执行器的损害以及不必要的火灾发生； 3.启动远行，应注意并通知周边的学生，头、手、衣物等切勿靠近运行部件（如：三相电机带动皮带和传动糸统等），以防止不必要的损伤； 6.检测时可通过面板原理图上进行检测，不用拔拉插头，以防插头接触不良; 7.在下列情况下必须踩刹车，输出轴转速停止后方能换挡：退回P档； N档或其他前进档（D\2\L）档换回R档时三．实训准备工作设备实训前应准备工作： 1.检查设备是否有安装蓄电池，电压是否充足； 1.380V三相电压是否安全接解完好 2，220v二相电压是否安全接解完好 3.检查变速器排档油是否正常； 5. 远行时，检查变速器是否有异响、运行是否正常等，如有不正常请及时联系生产厂家进行维修； 7变速器.运行后检查是否漏油、漏水等； 8.检查检测面板上的测量端子是否有松动，信号表及各个指示灯是否工作正常； 9.熟练操作实训设备，掌握发动机各个传感器、执行器的安装位置与性能特征。四．使用操作说明： 1.安装好蓄电池，闭合电源总开关（顺时针闭合，逆时针断开），电源总开关位于挂档杆侧； 2.打开点火开关至ON，检查仪表指示灯是否正常； 3.启动发动机（启动发动机前应通知周边学生），可用万用表在检测面板上进行检测； 4.面板右侧有故障设置区，‘0’为断路，‘1’为通路（即正常）； 5.设置故障后可安排学生进行检测以及故障判断与分析； 5.面板上安装有信号表，指示各传感器与执行器的信号电压；五．实训项目： 1.蓄电池的安装； 2.各个传感器与执行器的安装位置以及性能； 3.传感器的检测； 4.传感器设置故障后出现的异常现象，传感器的故障判断与 5.示波器的使用与分析。 6.变速器档位开关实训； 7变速器的油面检查、油质检查、油门拉索检查与调整、机械系统测试（失速试验、时滞试验、油压测试）等六．实训完毕后备事项 1.断开电源总开关，以备下次使用； 2.记录实训设备是否有故障未解决（如有故障及时通知厂家或安排专业人员维修）； 3.记录下次使用时需准备的材料（含易损件）； 4.保持实训台干净整洁，并摆放归位展开

用化学符号表示：（1）两个钙原子______；（2）4个二氧化硫分子_...: 用化学符号表示：（1）两个钙原子______；（2）4个二氧化硫分子______；（3）水______；（4）2个亚铁离子______；（5）氧化镁中的镁元素呈正二价+2MgO+2MgO；（6）两个碳酸根离子______；（7）氧化钠______；（8）氢氧化钙：... 用化学符号表示：（1）两个钙原子______；（2）4个二氧化硫分子______；（3）水______；（4）2个亚铁离子______；（5）氧化镁中的镁元素呈正二价+2MgO+2MgO；（6）两个碳酸根离子______；（7）氧化钠______；（8）氢氧化钙：______．展开

战地2就战地2嘛，什么男朋友2:

【化学问题】碱能不能与金属氧化物反应，如2NaOH＋CuO＝Cu(OH)2↓＋Na2O ？: 【化学问题】碱能不能与金属氧化物反应，如2NaOH＋CuO＝Cu(OH)2↓＋Na2O ？？

化学作业:将2钥匙小苏打加入一只干净的玻璃杯中会怎么样?:

断路器S263H/C25*2*2什么意思:

英语翻译(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 展开

电磁继电器2开2闭什么意思

难溶于水的非金属氧化物是（　　） A．MnO 2 B．CO 2 C．NO 2 D．SiO: 难溶于水的非金属氧化物是（　　） A．MnO 2 B．CO 2 C．NO 2 D．SiO 2

狙击精英2提示鼠标按键2探头什么是鼠标按键2:

比例式3：2减压阀3：2是什么意思:

电解质溶液2: 请逐步分析以下题中所有步骤目的及加星号的试剂的简单性质：准确称取0.1500g Mg-Al合金（含有镁铝硅等）试样于150毫升烧杯中，加入约10mL*混合酸，并立即加盖表面皿，待试样溶解后，用水冲洗表面皿和杯壁，将溶液转移至100mL容量瓶中，稀释至刻度，摇匀。用移... 请逐步分析以下题中所有步骤目的及加星号的试剂的简单性质：准确称取0.1500g Mg-Al合金（含有镁铝硅等）试样于150毫升烧杯中，加入约10mL*混合酸，并立即加盖表面皿，待试样溶解后，用水冲洗表面皿和杯壁，将溶液转移至100mL容量瓶中，稀释至刻度，摇匀。用移液管吸取25mL试液于250mL锥形瓶中，加入0.02mol\L的EDTA溶液20mL，*二甲酚橙指示剂，用氨水调至溶液恰呈紫红色，然后滴加稀盐酸三滴，将溶液煮沸三分钟左右，冷却，加入百分之20的六次甲基四胺溶液20mL，此时溶液应呈黄色，如不呈黄色，可再用盐酸调节。再补加二甲酚橙2滴，用cmol\L的*锌标准溶液滴定至溶液由黄色变为紫红色，用去锌标准溶液体积V1毫升，加入20%NH4F溶液10mL，将溶液加热到微沸，流水冷却，再补加稀盐酸使溶液显黄色。再用cmol\L的锌标准溶液滴定至溶液由黄色变为红紫色时，即为终点，用去锌标准溶液体积V2. 附问题 <1>列出计算合金中铝的质量分数的表达式 <2>为什么不用标准的EDTA溶液直接滴定来测铝离子 <3>加入20%NH4F溶液10mL的目的是什么 <4>实验完毕后要注意什么展开

孤岛危机2: Z近没时间玩孤岛2，孤岛2都照孤岛1改了什么啊，什么刷点，什么收集物品，都是些什么啊？刷点有什么用啊？我out了？求高人解答。

帮忙翻译2: 3.6. Advantages of chromia as promoter in copper-based Catalysts It should also be noted from Figs. 5 and 6 that in the steam reforming reaction to produce hydrogen for fuel cell applications， trace quantities (<0.4 wt.%) of Cr2O3 on Cu... 3.6. Advantages of chromia as promoter in copper-based Catalysts It should also be noted from Figs. 5 and 6 that in the steam reforming reaction to produce hydrogen for fuel cell applications， trace quantities (<0.4 wt.%) of Cr2O3 on Cu not only doubled the activity for the MSR but also halved the amount of CO formed， thereby enhancing H2 production. This improved selectivity reduces the problem of H2 separation from the reaction products in fuel cell applications. An important finding in this research is the role that very small amounts of Cr2O3 play in all the reactions investigated， namely， methanol synthesis， water gas shift and methanol steam reforming. In commercial co-precipitatedcopper-based methanol synthesis catalysts， copper is known to be the active component [3]. More recently， it has becomeestablished that ZnO promotes methanol synthesis and that surface species formed by Cu-ZnO interaction are responsible for methanol synthesis [42]. The role of Cr2O3 in commercial catalysts is thought to be similar to that of Al2O3， which is to act as stabilizer of the structure of the copper catalyst， thereby reducing sintering. In this study， as in a previous one [18] using a different technique todeposit chromia on the surface of skeletal copper， we have shown that Cr2O3 has a significant role in copper-based methanol synthesis from CO2. That role is to improve the methanol yield by reducing the RWGS reaction (Fig. 3) aswas observed in the earlier study [18]. A major finding of this study has been the very strong evidence the Cr2O3 has a synergistic effect on the activity of copper for methanol synthesis， methanol steam reforming and the water gas shift reactions. From Figs. 4 and 5 it can be seen that 0.85 wt.% Cr2O3 enhances the specific activity (mol/hm2 Cu) of skeletal copper 270% for the WGS and 150% for methanol steam reforming. In the case of methanol synthesis (Fig. 2) 0.61 wt.% Cr2O3 increases the specific activity of copper by 67%. The results for the WGS and MS reactions are similar to those obtained under the same reaction conditions using skeletal copper promoted by Cr2O3 which was deposited from sodium chromate in the caustic leach liquor [28]. In that study， the effect of chromia was more pronounced， with an increase in activity of 950% for theWGSand 168% for the MSR reaction， respectively， using skeletal copper containing 0.75 wt.% Cr2O3. For methanol synthesis over Cr2O3 promoted skeletal copperprepared using sodium chromate in the leach liquor， Ma et al. [18] observed no increase in the specific activity of copper. 展开

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