排序方式: 共有67条查询结果,搜索用时 15 毫秒
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氧化铝基COS、CS_2水解催化剂表面碱性和催化作用 总被引:8,自引:0,他引:8
进行了3种氧化铝基催化剂上CO2的TPD和COS、CS2的水解活性研究.结果表明,催化剂表面碱性中心类型、强度和数目是不相同的;K2O和Pt的负载能提高弱碱性中心的数目和强度,同时能显著提高COS、CS2的水解转化率.关联第一类CO2脱附活化能和峰面积与COS水解反应活化能和速率常数,发现呈线性关系,说明弱碱性中心是COS催化水解的活性中心.关联第一、二两类CO2脱附峰面积与CS2水解速率常数,指出弱、次弱两类碱性中心均参与了CS2催化水解.催化剂表面上能量的分布是不均匀的. 相似文献
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G. Mink 《Reaction Kinetics and Catalysis Letters》1999,68(2):221-227
Under steady state conditions also La2O3 and ThO2, both having strong ionic character, unfilled d- and f-orbitals and a large metal ion radius proved to be order(s) of magnitude
more active than oxides of s, sp and d-metals. 相似文献
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RIG-G基因是利用全反式维甲酸(ATRA)诱导,采用差异显示PCR方法从APL细胞系NB4中克隆到的一个新基因。采用酶母双杂交的方法筛到了与RIG-G发生相互作用的JAB1。由于在酵母这种低等真核细胞中缺少诸如高等真核细胞中各种保证蛋白正常生物学功能发挥所必需的翻译后修饰,这种方法筛到的阳性克隆并不一定代表了真实的作用,所以在COS7细胞中采用了CO-IP(co-immunoprecipitation)实验,间接法、直接法均证实了这种相互作用。 相似文献
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The central spot of COS beam (CS-COS) can be obtained from COS beam by using the zero field truncation technique. The transversal intensity distributions of CS-COS through three different kinds of aperture functions are simulated numerically from the near field to the far field. It is shown that the CS-COS has the property of eliminating the diffraction fringes in the whole propagation process if a suitable aperture is introduced. 相似文献
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Meisheng Liang Chunhu Li Hanxian Guo Kechang XieState Key Laboratory of Cl Chemistry Technology Architecture Environmental College Research Institute of Coal Chemical Engineering Taiyuan University of Technology Taiyuan China 《天然气化学杂志》2002,(Z2)
The adsorptions of COS, H2S and O2 were investigated over the TGH catalyst in this paper. It was found that the numbers of basic centers and basic intensities were reduced over the deactivated TGH catalyst. The PT-IR results of COS+H2S+O2 co-adsorption on the TGH catalyst show that the main causes of catalyst deactivation is the formation of element sulfur and trace sulfate. 相似文献
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提取麻疹病毒Nepal毒株的RNA并利用逆转录PCR方法特异性地扩增血凝素基因(Hemagglutinin).将H基因克隆并测定序列,结果表明新毒株的H基因与标准疫苗毒株Edmonston之间存在较多重要的基因变异,两者的同源性为98.17%.将H基因克隆到表达载体pCD-SRα中并利用电转染法转染COS-7细胞,利用血凝实验检测了H蛋白的表达及功能 相似文献
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面向21世纪的海岸海洋科学 总被引:9,自引:3,他引:9
面对人口、资源与发展等当代一系列重大而紧迫的社会环境问题,在地球系统科学思想(ESS)指导下,以国际地圈-生物圈计划(IGBP)为代表的全球变化(GC)研究工作相继展开。20世纪90年代中期,以IGBP新的核心项目“海岸带海陆相互作用研究”(LOICZ)的建立为标志,海岸海洋代表了当代对海岸的新认识,并成为全球变化研究的关键地区,加之,“联合国海洋法公约”正式实施,迫切需要建立新的国际海洋秩序,因此,20世纪末,海岸海洋科学(COS)在世界范围内兴起,并与全球变化研究紧密结合,成为21世纪科学的热点。 相似文献
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In this paper, we consider some dividend problems in the classical compound Poisson risk model under a constant barrier dividend strategy. Suppose that the Poisson intensity for the claim number process and the distribution for the individual claim sizes are both unknown. We use the COS method to study the statistical estimation for the expected present value of dividend payments before ruin and the expected discounted penalty function. The convergence rates under large sample setting are derived. Some simulation results are also given to show effectiveness of the estimators under finite sample setting. 相似文献