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31.
任鸣 《宁波大学学报(理工版)》2007,20(3):417-420
通过对浙江会展旅游现状的分析和研究,总结了浙江会展旅游业的现状与优势,指出了面临的问题,进而从政府与会展企业角度提出了发展浙江会展旅游业的对策. 相似文献
32.
设$(A,B,V,W,\psi,\phi)$是一个Morita Context,具有一对零态射$\psi=0$, $\phi=0$, $C =\left ( \begin{array} {cc}A & V \\W & B \end{array}\right)$是对应的Morita Context环.本文给出了$C$与$A,B,V,W$之间关于环的$\pi$-正则性、semiclean性、Mophic性和环的Exchgange性、Potent性、GM性的关系. 相似文献
33.
Pinning effect of lead lanthanum titanate (PLT) ferroelectric thin films with excess PbO of 20 mol% has been studied for deposition on diffe rent substrates. Silicon, sapphire and quartz were used as substrates on which P t/Ti or LaNiO3 thin films were deposited as bottom electrodes. Electron probe analysis results showed that there was still a certain amount of excess Pb in PLT films after annealing at 550 ℃ for 1 h, and the amount of it was dependent on the substrate used. The distribution of excess Pb in the films was investig ated by Auger electron spectroscopy depth profile. It was shown that the substrates and the bottom electrodes had significant effects on the content and distrib ution of excess Pb in PLT films. The excess Pb and its accumulation at the inter face between the film and bottom electrode may act as pinning centers and have a pinning effect on domains, which can be observed by abnormal P-E hysteresis loops and abnormal C-V curves. The excess Pb content in the films and the accumulation of Pb at the interface were high in PLT films deposited on Pt/Ti/S i, and considerable pinning effect was observed. As LaNiO3 would absorb most part of the excess Pb in PLT films, the content of excess Pb in the films deposited on LaNiO3/Si was very low and the pinning effect was hardly observed. 相似文献
34.
在假设算子方程解存在的前提下,给出了以解为中心的一个球域,证明了当初始点落到这个球域时,用于判断简化Newton方法收敛性的Kantorovich定理的条件必然满足,从而由简化Newton方法产生的迭代序列收敛. 相似文献
35.
本论述了吉林省农林天敌昆虫双翅目的8科,即食虫虻科、蜂虻科、食蚜蝇科,眼蝇科、长足蝇科、突颜寄蝇科、麻蝇科、寄蝇科,共258种。对这些种类的分布及其食性进行了详细的描述。 相似文献
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37.
HUANG Xiao-wen SHI Peng-fei 《高等学校化学研究》2006,22(1):73-75
IntroductionLithium ion batteries are key components of mobiletelephones and portable computers.Among the knownLi-intercalation materials for lithium ion battery cath-odes,LiCoO2,LiNiO2,and LiMn2O4have been stud-ied extensively[1—3].LiCoO2is nowused in c… 相似文献
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39.
Electrochrometic measurements were carried on the Z-type Langmuir-Blodgett films oftwo liquid crystalline polymers: mono-{6-[4-(phenylazo) naphthyloxy] hexyl} (1a) andmono-{6-[4-(anthraquinone-1-azo) naphthyloxy] hexyl} (2a) ester of polymaleic acid. Itwas found that for both polymers, poling fields parallel and antiparalle1 to dipole momentsof the polymer side chains induce red and blue shift in absorption bands, respectively. Forpolymer la blue shift is accompanied by absorbance increase, while red shift by absorbancedecrease;but for polymer 2a only decrease in absorbance is observed. A simple model wasproposed to analyze the results. 相似文献
40.
The imidazole covalently coordinated sandwich-type heteropolymngstates Na9[ {Na(H=O2}3{M(C3H4N2)}3( Sb W9O33)2]·xH=O(M=Ni^Ⅱ, Co^Ⅱ, Zn^Ⅱ, Mn^Ⅱ) were obtained by the reaction of Na2WO4·2H2O, SbCl3·6H2O, NiCl2·6H2O [MnSO4·H2O, Co(NO3)2·6H2O, ZnSO4·7H2O] and imidazole at pH≈7.5. The structure of Na9[{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2]·32H2O was determined by single crystal X-ray diffraction. Polyanion [{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2}3]^9- has approximate C3v symmetry, imidazole coordinated six-nuclear duster [{Na(H2O)2}3{Ni(C3H4N2)}3]^9+ is encapsulated between two (α-SbW9O33)^9-, the three rings of imidazole in the polyanion are perpendicular to the horizontal plane formed by six metals (Na-Ni-Na-Ni-Na-Ni) in the central belt, and x-stacking interactions exist between imidazoles of neighboring polyanions with dihedral angel of 60%. The compounds were also characterized by IR, UV-Vis spectra, TG and DSC, and the thermal decomposition mechanism of the four compounds was suggested by TG curves. 相似文献