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101.
(η^2—C60)[Pt(PPh3)2]8的合成与表征 总被引:6,自引:2,他引:6
C60是高度共轭的宠状结构碳素体.分子结构中六元环间的共价碳碳双键是富电子区,其反应性能与烯键类似,以碳碳双键与中心金属形成η2配位化合物.富勒烯η2配合物的合成及性能研究是当前研究热点之一[1~7].本文在(η2-C60)[Pt(PPh3)2]n(n=1~6)系列研究[7]的基础上制备了(η2-C60)[Pt(PPh3)2]8,并用元素分析、红外光谱和光电子能谱进行鉴定和表征.1实验部分四(三苯基膦)合铂Pt(PPh3)4按文献[8]方法制备;C60纯度为99%;其余试剂均为分析纯.元素分析在ERLA-1106型元素分析仪上进行;光电子能谱在VGESCA… 相似文献
102.
The cyclohexamethylene-diamine squaric acid platinum(Ⅱ) complexs(R,R, S,S) binding to G-actin and the consquence conformation change were studied by N-(1-pyrenyl) maleimide(NPM) labeled fluorescence and intrinsic fluorescence. The binding and chemical kinetics were determined by fluorometry. The results showed that when R (Pt/actin molar ratio) was lower than 30, the Pt binded to G-actin strong binding sites(-SH), when R was larger than 30, the Pt binded to G-actin weaker binding sites. The consquence conformation changes were determined by CD. The CD results showed that R was smaller than 60, G-actin α-helix contents decreased slowly, R was larger than 60, G-actin conformation changed obviously. The reaction of R,R complex of platinum(Ⅱ) S,S complex of platinum(Ⅱ) with G-actin was similar to that of with S,S complex of platinum(Ⅱ). 相似文献
103.
The growth of cobalt hexacyanoferrate (CoHCF) films on bare and Au-colloid-modified electrodes in nitrate or sulfate solutions was monitored by electrochemical quartz crystal microbalance. The average efficiency of CoHCF film growth for Au colloid modified electrodes is 23 and 12 ng cm(-2) s(-1) in KNO3 and K2SO4 solutions, respectively, while those values for the bare gold electrode are 15 and 9 ng cm(-2) s(-1), respectively. In K2SO4 solution, the apparent molar masses for the Au-colloid-modified electrode at lower and higher potential is 58.4 and 37.3 g mol(-1), respectively, which is larger than those for the bare gold electrode (51.7 and 26.3 g mol(-1), respectively). The respective results were also obtained in KNO3 solution. Furthermore, the difference of the apparent molar masses at lower and higher potential for Au-colloid-modified electrodes is smaller than that for bare gold electrodes in the same electrolyte. Additionally, the mechanism of charge propagation is dependent on different anions in electrolyte solutions at higher potentials where the second redox reaction of CoHCF occurs. Therefore, the existence of Au colloids can accelerate CoHCF film growth and weaken the effect of anions on mass transport. 相似文献
104.
溶胶凝胶法制氧化铝负载铜基超细粒子催化剂的研究 总被引:9,自引:1,他引:9
采用溶胶凝胶法制氧化铝负载铜基超细粒子催化剂的制备了氧化铝负载的铜基超细粒子催化剂,用TG-DTA,XRD,BET以及TEM等技术手段,对催化剂的物相结构,表面孔结构,粒子形貌以及催化性能等进行了研究。结果表明,利用溶胶凝胶法,可以直接帛备出高比表面积,低堆积密度的纤维状纳米级负载型Cu/Al2O3超细粒子;活性组分以远低于纳米级的微晶粒子簇状态,均匀地分散在纳米级氧化铝载体表面上,而且在低于50 相似文献
105.
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107.
GuoXiangCHENG GuangLingPEI LingGangZENG LiYongZHANG ChaoLIU 《中国化学快报》2004,15(2):242-245
In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788),the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer,cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed. 相似文献
108.
先在0.5 mol·L-1硝酸介质中活化氟离子选择性电极,再在含硝酸的总离子强度调节混合液(TISAM)中测定氟,线性范围为1×10-7~1×10-2mol·L-1,检出限为1.9μg·L-1。该方法应用于绿茶饮料、水、牛奶中痕量氟的测定,结果的RSD小于4.8%,回收率在96.1%至100.2%之间,对氟离子选择性电极在硝酸介质中的活化机理作了阐述。 相似文献
109.
Fusarin C (FC) is a mutagenic and carcinogenic mycotoxin which was isolated from Fu-sarium moniliforme culture extracts. The Fusarium moniliforme is one of most prevalent fungi found on corn in Linxian, a high risk area for esophageal cancer. This paper reports, for the first time, the malignant transformation of rat esophageal epithelial cells induced by FC. The transformed cells showed several characteristics of transformation. Colonies were formed after seeding these transformed cells either into selective medium free of epidermal growth factor (EGF) and serum, or on semi-solid agar; there was an increase in chromosome number; the expression of c-myc and v-erb-B oncogenes was enhanced in the cells; and squamous cell carcinomas arose after inoculating the cells into nude mice. The results demonstrated transforming effect of FC on rat esophageal epithelial cells, and indicate that the abnormal expression of some oncogenes could serve as a hew property of transformed cells. 相似文献
110.
A theoretical study on the velocity of electroosmotic flow (EOF) and the retention times of neutral solutes under multiple-step gradient of capillary electrochromatography (CEC) was carried out, focusing on that with three kinds of mobile phases. Through the model computations, the detaining time of the second kind of mobile phase in the column was proved to play an important role in affecting EOF. The variation speed of EOF was shown to be determined by the differences among dead times in different steps. In addition, the prediction of the retention times of 13 aromatic compounds under gradient mode was performed with the deduced equations. A relative error below 3.3% between the calculated and experimental values was obtained, which demonstrated the rationality of the theoretical deduction. Our study could not only improve the comprehension of stepwise gradient elution, but also be of significance for the further optimization of separation conditions in the analysis of complex samples. 相似文献