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161.
AN Ya XU Jun ZHANG Jin HU Changgang LI Ganzuo WANG Zhining WANG Zhongni ZHANG Xiaoyi & ZHENG Liqiang . Key Lab of Colloid Interface Chemistry for State Education Ministry Jinan China . College of Science Guizhou Normal University Guiyang China 《中国科学B辑(英文版)》2006,49(5)
The pseudo-quaternary phase diagram of Brij35/sodium oleate/oleic acid/water systems has been investigated, and the liquid crystal area has been identified, which covers about two thirds of the whole phase diagram. The liquid crystal structure and behavior have been also studied by using polarizing texture, small angle X-ray scattering, 2H-NMR and rheometer etc. The result shows that when the composition of the system changes along the line of AA′ in this large liquid crystal region, the structural change is cubic→cubic/lamellar→lamellar→lamellar/hexagonal→hexagonal. Meanwhile, we made the first attempt of systematic study of the rheological properties of the above system. The lattice constants of cubic and hexagonal liquid crystals are 10.53 and 5.68 nm, respectively. 相似文献
162.
Huang M Jin Y Jiang H Sun X Chen H Liu B Wang E Dong S 《The journal of physical chemistry. B》2005,109(32):15264-15271
Multiple-deposited Pt overlayer modified Pt nanoparticle (MD-Pt overlayer/PtNPs) films were deliberately constructed on glassy carbon electrodes through alternately multiple underpotential deposition (UPD) of Ag followed redox replacement reaction by Pt (II) cations. The linear and regular growth of the films characterized by cyclic voltammetry was observed. Atomic force spectroscopy (AFM) provides the surface morphology of the nanostructured Pt films. Rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry demonstrate that the MD-Pt overlayer/PtNPs films can catalyze an almost four-electron reduction of O(2) to H(2)O in air-saturated 0.1 M H(2)SO(4). Thus-prepared Pt films behave as novel nanostructured electrocatalysts for dioxygen reduction and hydrogen evolution reaction (HER) with enhanced electrocatalytic activities, in terms of both reduction peak potential and peak current, when compared to that of the bulk polycrystalline Pt electrode. Additionally, it is noted that after multiple replacement cycles, the electrocatalytic activities improved remarkably, although the increased amount of Pt is very low in comparison to that of pre-modified PtNPs due to the intrinsic feature of the UPD-redox replacement technique. In other words, the electrocatalytic activities could be improved markedly without using very much Pt by the technique of tailoring the catalytic surface. These features may provide an interesting way to produce Pt catalysts with a reliable catalytic performance as well as a reduction in cost. 相似文献
163.
合成了六种轻希土硫氰酸盐与标题不饱和冠醚的新固体配合物,进行了元素分析,摩尔电导率、DTA、UV、IR和XPS等表征。对Ln(NCS)_3·L和Ln(NCS)_3的XPS研究中,得到它们组成原子芯能级电子(Ln3d_(5/2),Ols,Nls,S2p)的结合能信息;观察到除Y3d_(5/2)外Ln3d_(5/2)(Ln=La、Ce、Pr、Nd、和Sm)的伴峰结构,Ln3d_(5/2)结合能与原子序数呈线性关系,并推断类似化合物Pm3d_(5/2)结合能在1035eV附近. 相似文献
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167.
An analytical method has been developed for determination of dextromethorphan (DMP) and dextrorphan (DRP) in human hair by gas chromatography–mass spectrometry (GC–MS). Hair samples (30 mg) were washed with distilled water and acetone and cut into small fragments (<1 mm) before extraction with methanol. The extracts were evaporated to dryness and then derivatized by use of BSTFA containing 1% TMCS, for preparation of the trimethylsilyl (TMS) derivative of DRP. The extract (1 μL) was then injected into the GC–MS. Recoveries of DMP and DRP at 7.0 and 22.5 ng mg?1 were in the range 90.6–97.2% with intra-assay and inter-assay precision of less than 5.7% and 4.7%, respectively. LOD and LOQ were, respectively, 0.67 and 2.13 ng mg?1 for DMP and 0.14 and 0.47 ng mg?1 for DRP. The responses were linear with correlation coefficients (r > 0.9995) for the drugs studied. The applicability of the method was proven by analysis of authentic hair samples. 相似文献
168.
The reduction of C = C double bonds is one of the most fundamental synthetic transformations and plays a key role in the manufacturing of a wide variety of bulk and fine chemicals. Hydrogenation of olefinic substrates can be achieved readily with molecular hydrogen in many cases, but transfer hydrogenation methods using suitable donor molecules such as formic acid or alcohols are receiving increasing attention as possible synthetic alternatives because it requires no special equipment and avoids the handling of potentially hazardous gaseous hydrogen. 相似文献
169.
以十四酸根阴离子柱撑Zn-Al水滑石Zn0.77Al0.22(OH)2.0.22C13H27COO.0.81 H2O(记为ZnAl-14A)为预撑前体,在水溶液中用离子交换法将以2∶17缺位杂多酸根离子(P2Mo16VO61)11-记为(P Mo V)为配体的稀土杂多配阴离子Ce(P2Mo16VO61)219-(记为Ce(PMoV)2)插层组装到水滑石层板间,合成了一种具有大的层间距(3.37 nm)的超分子插层材料Zn0.77Al0.23(OH)2.0.0105[Ce(P1.9Mo15.7V1.1O61)2].0.011C13H27COO.0.83H2O(记为ZnAl-Ce(PMoV)2)。用ICP,IR,XRD和DTA对产物的组成和结构进行了表征。结果表明,该产物中Ce(PMoV)2配阴离子沿其长轴垂直于层板的方向分布于水滑石层间;产物具有规整的层状结构和热稳定性;产物对乙酸与正丁醇的酯化反应,二甘醇的脱水-环化反应和H2O2氧化环己烷的反应有良好的催化性能,且易于回收重复使用。 相似文献
170.
Guo Hua GAO Jin Bao GAO Wen Juan ZHOU Liang LU Ming Yuan HE 《中国化学快报》2006,17(10):1293-1296
Since much more attention has been paid to the sustainable development, many researchers try to improve conventional chemical process and find new and more, environmentally friendly routes1. Aqueous-phase reactions are of interest as environ- mentally ben… 相似文献