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101.
Tin dioxide nanoparticles of 5 nm in size were prepared on NaY zeolite external surface by impregnation of SnCl2 solution and subsequent calcination at 623 K. A SnO2-NaY based chemical sensor for detecting H2 was demonstrated. 相似文献
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A novel compound, [Co(phen)3][V10O26]·H2O, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group Ccca with a=13.447(3), b=29.936(6), c=23.252(5) Å, V=9360(3) Å3, Z=8 and R=0.0285. Data were collected on a Rigaku R-AXIS RAPID IP diffractometer at 293 K in the range of 1.36<θ<24.99°. The structure of the compound consists of vanadium oxide layers, which are built up from the infinite VO4 chains by corners and edges sharing. The [Co(phen)3]2+ complexes occupy the interlayer space and contact each other via π−π stacking interactions of the phen groups to form infinite one-dimensional chains. 相似文献
104.
Polymeric micelles based on amphiphilic diblock copolymers methoxy poly(ethylene glycol)-polylactide with various hydrophobic lengths were designed as carriers of poorly water-soluble anticancer drug methotrexate (MTX). Relationship between physicochemical characteristics of micelles and release behavior was explored. The critical micelle concentration was determined by fluorescence spectroscopy using 9-chloromethyl anthracene as fluorescence probe. Core-shell type polymeric micelles were prepared by free-surfactant dialysis technique. The mean size of micelles loaded with MTX was 50-200 nm with narrow polydispersity. Physicochemical properties of drug-loaded micelles were evaluated. In vitro release behavior of MTX was also investigated. MTX was continuously released from micelles and less than 50% MTX was released in 5 days. Release rate was dependent on chemical structures of micelles and enhanced by decreasing polylactide lengths. 相似文献
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Shu Ping XU* Huan Wen CHEN Ai Min YU Qin Han JIN Hua Ying LIAO Changchun R&D Center for Analytical Instruments Department of Chemistry Jilin University Changchun Key Laboratory for Supramolecular Structure Spectroscopy of Ministr 《中国化学快报》2002,13(7):660-661
In recent years, the determination of Cr (VI) has attracted great attention because of its toxicity to human, plants and animals1-5. Usually, in the industrial waste water, the concentration of Cr (VI) is relatively high and should be determined frequently. So, an accurate, quick, and convenient method for the measurement of Cr (VI) in environmental water, as well as in river, lake, sea and tap water, is of great importance. The method for determination of Cr (VI) by diphenylcarbazine … 相似文献
108.
Jun WANG Kai Ying LIU Li WANG Ji Ling BAI 《中国化学快报》2006,17(1):49-52
The techniques of combinatorial chemistry have recently been applied to the discovery of new asymmetric catalyst for a variety of organic transformations1-3. Using combina- torial methods, it is straightforward to generate thousands of potential asymmetri… 相似文献
109.
建立了处理双原子分子-表面相互作用的推广的LEPS势.借助推广的LEPS势,系统研究了一氧化碳分子在铂低指数表面吸附的动力学特性,重现了低指数表面的分子吸附热、吸附几何及本征振动等实验数据;鉴定了某些不合理的文献信息,预测了实验尚未探测到的重要信息:预测到Pt(100)表面四重洞位的C-O伸缩振动频率为1 962.60 cm-1;预测到Pt(110)表面吸附态的C-O及C-Pt键长分别为115.1、147 pm. 相似文献
110.
前驱体水解对纳米铂形状控制合成的影响 总被引:5,自引:1,他引:5
以聚丙烯酸钠(NaPA: M_w ≈ 2100)为保护剂,对比研究了H_2还原K_2PtCl_4 和K_2PtCl_6水溶液制备纳米铂晶粒的形状选择性,揭示了前驱体的水解对纳米铂 晶粒的形状控制合成具有显著影响。文献中通常采用的合成立方形状纳米铂的 K_2PtCl_4前驱体在水溶液中不稳定,避光静置一周会析出黑色沉淀。这种不稳定 性导致了以K_2PtCl_4为Pt前驱体的合成结果难以重复。相比而言,避光静墨的 K_2PtCl_6水溶液很稳定,以它为前驱体合成的纳米铂通常为削角八面体。 K_2PtCl_6水溶液暴露于室内光线中会出现[PtCl_6]~(-2)的光致水解。当[PtCl_6] ~(2-)的紫外特征吸收峰(260nm)由于光致水解完全消失后,以聚丙烯酸钠为保护剂 ,通过H_2还原可以有选择性地(约80%)合成由{100}晶面包裹的立方体形状的纳米 铂。 相似文献