化學專業(yè)翻譯2

whsxiaolong 2007-03-16 05:16:39 438 瀏覽

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. 展開

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老末 2007-03-17 00:00:00

今對有效實驗數(shù)據(jù)總結(jié)如下，水溶液中合成的硫醇包被碲化鎘納米晶代表著一種穩(wěn)定、GX發(fā)光的殼－芯量子點體系，該體系帶有和表面鎘原子緊密結(jié)合的巰基官能團產(chǎn)生的硫化物自然包被表面(硫化鎘外殼)。所有使用的化學品是分析純或Z高純度的。用來制備碲化氫的碲化鋁購于CERAC公司，WI. Milli-Q水(Millipore公司)用作溶劑。紫外吸收光譜用Cary 50 分光光度計(Varian公司)記錄。光致發(fā)光用FluoroMax-2 熒光分光光度計(Instruments SA公司)在室溫下操作。碲化鎘納米晶在室溫下的光致發(fā)光量子效率按照文獻41中的步驟進行估計，該步驟中，用待測樣和羅丹明6G (激光純Lambda Physik公司)的乙醇(Uvasol公司)溶液進行比較，并假定后者的光致發(fā)光量子效率為95%（42）。高分辨率透射電鏡和能量色散X射線分析用Philips CM-300型電鏡在300 kV下操作。透射電鏡樣品用下述方法制備：碲化鎘納米晶轉(zhuǎn)移到甲苯中配成稀釋溶液(與包被劑1-十二烷基硫醇在表面進行交換)，然后滴加到 400目碳涂布的銅網(wǎng)上并立刻揮發(fā)去過量的溶劑。粉末X-射線衍射儀 were carried out with a Philips X¢Pert 散射儀(Cu KR-照射，可變光柵狹縫，Bragg-Brentano 幾何儀，次級單色儀)。本研究使用的樣品用分散良好的碲化鎘納米晶粉末置于標準硅支持體上的方法制備。為了研究碲化鎘膠體量子點的光穩(wěn)定性，稀釋的膠體溶液用450 W的氙氣燈發(fā)出的光在不同時間間隔進行照射，該光線在400 nm左右處被一個帶寬40 nm和峰轉(zhuǎn)移40%的窄帶濾光片過濾。 A 這里的“穩(wěn)定”指的是碲化鎘膠體量子點的膠體溶液在室溫下黑暗空氣中儲存幾個月甚至幾年是穩(wěn)定的?！爸械取敝傅氖悄z體溶液儲存期間偶然發(fā)生凝固現(xiàn)象；然而，它們一般在幾個月內(nèi)是穩(wěn)定的。不加穩(wěn)定劑時密封包裝或聚合物膜覆蓋的碲化鎘膠體量子點粉末在空氣中幾年內(nèi)是穩(wěn)定的(不被氧化，光學性質(zhì)沒有或者僅有微小變化)。 B 納米晶體的電勢用帶有相反電荷液滴的ú-電位儀來估計。選擇實驗條件使得單層納米顆粒吸收后液滴的ú-電位發(fā)生變化。

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化學專業(yè)翻譯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. 展開

求助化學專業(yè)翻譯，謝謝: 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. 展開

專業(yè)翻譯: 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. 展開

關(guān)于五金件表面處理PAINTING的專業(yè)翻譯: 鈑金機殼表面處理要求描述如下： 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... 鈑金機殼表面處理要求描述如下： 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. 請問， 1. 上面的英文描述的專業(yè)翻譯是什么？ 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是什么標準嗎？哪里有相關(guān)的資料？展開

尿維素C(VC干化學+2正常嗎:

2，酶只能改變化學反應(yīng)的活化能不能改變化學反:

中文翻譯成英文，汽車變速器實驗臺使用說明.求專業(yè)翻譯，謝絕機器翻譯: diyi章操作說明一.實驗臺簡介1.實驗臺示意圖2.故障設(shè)置二．使用注意事項：1.380V三相電壓是否安全，2，220v二相電壓是否安全，2.安裝蓄電池時必須注意正負極《220V變壓12V.DC》，安裝錯... diyi章操作說明一.實驗臺簡介 1.實驗臺示意圖 2.故障設(shè)置二．使用注意事項： 1.380V三相電壓是否安全， 2，220v二相電壓是否安全， 2.安裝蓄電池時必須注意正負極《220V變壓12V.DC》，安裝錯誤容易導致控制模塊、傳感器與執(zhí)行器的損害以及不必要的火災(zāi)發(fā)生； 3.啟動遠行，應(yīng)注意并通知周邊的學生，頭、手、衣物等切勿靠近運行部件（如：三相電機帶動皮帶和傳動糸統(tǒng)等），以防止不必要的損傷； 6.檢測時可通過面板原理圖上進行檢測，不用拔拉插頭，以防插頭接觸不良; 7.在下列情況下必須踩剎車，輸出軸轉(zhuǎn)速停止后方能換擋：退回P檔； N檔或其他前進檔（D\2\L）檔換回R檔時三．實訓準備工作設(shè)備實訓前應(yīng)準備工作： 1.檢查設(shè)備是否有安裝蓄電池，電壓是否充足； 1.380V三相電壓是否安全接解完好 2，220v二相電壓是否安全接解完好 3.檢查變速器排檔油是否正常； 5. 遠行時，檢查變速器是否有異響、運行是否正常等，如有不正常請及時聯(lián)系生產(chǎn)廠家進行維修； 7變速器.運行后檢查是否漏油、漏水等； 8.檢查檢測面板上的測量端子是否有松動，信號表及各個指示燈是否工作正常； 9.熟練操作實訓設(shè)備，掌握發(fā)動機各個傳感器、執(zhí)行器的安裝位置與性能特征。四．使用操作說明： 1.安裝好蓄電池，閉合電源總開關(guān)（順時針閉合，逆時針斷開），電源總開關(guān)位于掛檔桿側(cè)； 2.打開點火開關(guān)至ON，檢查儀表指示燈是否正常； 3.啟動發(fā)動機（啟動發(fā)動機前應(yīng)通知周邊學生），可用萬用表在檢測面板上進行檢測； 4.面板右側(cè)有故障設(shè)置區(qū)，‘0’為斷路，‘1’為通路（即正常）； 5.設(shè)置故障后可安排學生進行檢測以及故障判斷與分析； 5.面板上安裝有信號表，指示各傳感器與執(zhí)行器的信號電壓；五．實訓項目： 1.蓄電池的安裝； 2.各個傳感器與執(zhí)行器的安裝位置以及性能； 3.傳感器的檢測； 4.傳感器設(shè)置故障后出現(xiàn)的異常現(xiàn)象，傳感器的故障判斷與 5.示波器的使用與分析。 6.變速器檔位開關(guān)實訓； 7變速器的油面檢查、油質(zhì)檢查、油門拉索檢查與調(diào)整、機械系統(tǒng)測試（失速試驗、時滯試驗、油壓測試）等六．實訓完畢后備事項 1.斷開電源總開關(guān)，以備下次使用； 2.記錄實訓設(shè)備是否有故障未解決（如有故障及時通知廠家或安排專業(yè)人員維修）； 3.記錄下次使用時需準備的材料（含易損件）； 4.保持實訓臺干凈整潔，并擺放歸位展開

用化學符號表示：（1）兩個鈣原子______；（2）4個二氧化硫分子_...: 用化學符號表示：（1）兩個鈣原子______；（2）4個二氧化硫分子______；（3）水______；（4）2個亞鐵離子______；（5）氧化鎂中的鎂元素呈正二價+2MgO+2MgO；（6）兩個碳酸根離子______；（7）氧化鈉______；（8）氫氧化鈣：... 用化學符號表示：（1）兩個鈣原子______；（2）4個二氧化硫分子______；（3）水______；（4）2個亞鐵離子______；（5）氧化鎂中的鎂元素呈正二價+2MgO+2MgO；（6）兩個碳酸根離子______；（7）氧化鈉______；（8）氫氧化鈣：______．展開

戰(zhàn)地2就戰(zhàn)地2嘛，什么男朋友2:

【化學問題】堿能不能與金屬氧化物反應(yīng)，如2NaOH＋CuO＝Cu(OH)2↓＋Na2O ？: 【化學問題】堿能不能與金屬氧化物反應(yīng)，如2NaOH＋CuO＝Cu(OH)2↓＋Na2O ？？

化學作業(yè):將2鑰匙小蘇打加入一只干凈的玻璃杯中會怎么樣?:

斷路器S263H/C25*2*2什么意思:

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

電磁繼電器2開2閉什么意思

難溶于水的非金屬氧化物是（　　） A．MnO 2 B．CO 2 C．NO 2 D．SiO: 難溶于水的非金屬氧化物是（　?。? A．MnO 2 B．CO 2 C．NO 2 D．SiO 2

比例式3：2減壓閥3：2是什么意思:

電解質(zhì)溶液2: 請逐步分析以下題中所有步驟目的及加星號的試劑的簡單性質(zhì)：準確稱取0.1500g Mg-Al合金（含有鎂鋁硅等）試樣于150毫升燒杯中，加入約10mL*混合酸，并立即加蓋表面皿，待試樣溶解后，用水沖洗表面皿和杯壁，將溶液轉(zhuǎn)移至100mL容量瓶中，稀釋至刻度，搖勻。用移... 請逐步分析以下題中所有步驟目的及加星號的試劑的簡單性質(zhì)：準確稱取0.1500g Mg-Al合金（含有鎂鋁硅等）試樣于150毫升燒杯中，加入約10mL*混合酸，并立即加蓋表面皿，待試樣溶解后，用水沖洗表面皿和杯壁，將溶液轉(zhuǎn)移至100mL容量瓶中，稀釋至刻度，搖勻。用移液管吸取25mL試液于250mL錐形瓶中，加入0.02mol\L的EDTA溶液20mL，*二甲酚橙指示劑，用氨水調(diào)至溶液恰呈紫紅色，然后滴加稀鹽酸三滴，將溶液煮沸三分鐘左右，冷卻，加入百分之20的六次甲基四胺溶液20mL，此時溶液應(yīng)呈黃色，如不呈黃色，可再用鹽酸調(diào)節(jié)。再補加二甲酚橙2滴，用cmol\L的*鋅標準溶液滴定至溶液由黃色變?yōu)樽霞t色，用去鋅標準溶液體積V1毫升，加入20%NH4F溶液10mL，將溶液加熱到微沸，流水冷卻，再補加稀鹽酸使溶液顯黃色。再用cmol\L的鋅標準溶液滴定至溶液由黃色變?yōu)榧t紫色時，即為終點，用去鋅標準溶液體積V2. 附問題 <1>列出計算合金中鋁的質(zhì)量分數(shù)的表達式 <2>為什么不用標準的EDTA溶液直接滴定來測鋁離子 <3>加入20%NH4F溶液10mL的目的是什么 <4>實驗完畢后要注意什么展開

孤島危機2: Z近沒時間玩孤島2，孤島2都照孤島1改了什么啊，什么刷點，什么收集物品，都是些什么??？刷點有什么用啊？我out了？求高人解答。

幫忙翻譯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. 展開

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