Theoretical advances of the structures and catalytic activities of small-sized gold nanoclusters

Gold nanoclusters exhibit extraordinary catalytic activities,but the dominating factor is still unclear due to the complexity of the structures.In this review,we briefly summarized the recent theoretical progress on their structures and catalytic activities.Combining the experimental and theoretical efforts,the structures of small-sized gold clusters have been explored systematically.Based on the determined structures,factors that influence the catalytic capabilities of small-sized gold clusters(Au_(16)-Au_(35))are studied using CO oxidation asa probe.The preadsorption energies of CO and O_2are found strongly correlated with catalytic activities,which could be affected by the clusters'geometries,sizes,and charge distributions.In addition,the presence of water could significantly lower the activation energy barrier of O_2 dissociation to enhance the clusters'catalytic activities.     

Maximum likelihood estimator of the parameter for a continuous one-parameter exponential family under the optimal ranked set sampling

This paper studies a maximum likelihood estimator (MLE) of the parameter for a continuous one-parameter exponential family under ranked set sampling (RSS). The authors first find the optimal RSS according to the character of the family, viz, arrange the RSS based on quasi complete and sufficient statistic of independent and identically distributed (iid) samples. Then under this RSS, some sufficient conditions for the existence and uniqueness of the MLE, which are easily used in practice, are obtained. Using these conditions, the existence and uniqueness of the MLEs of the parameters for some usual distributions in this family are proved. Numerical simulations for these distributions fully support the result from the above two step optimizations of the sampling and the estimation method.     

宁波物流信息化水平现状及其发展对策探讨

以宁波地区为背景,介绍了物流信息化及其必要性,分析了宁波物流信息化的现状,探讨了宁波物流信息化存在的问题,提出了相应的对策。     

用ARX

基于客户     

土地开发整理中的权属管理研究——以吉林省西部土地开发整理重大工程为例

土地开发整理中的权属管理对巩固土地开发整理成果、提高土地利用效益、避免土地产权纠纷具有重要作用和意义.在论述土地开发整理权属管理的基本内容、方式和方法等的基础上,针对吉林省西部土地开发整理中的土地权属调整问题,提出了加强土地整理前期权属调查登记、规范权属调整运作等对策.     

创建机场鸟害防治实验室的探索与实践

迄今为止,鸟害给民航部门和军方造成了巨大的经济损失,甚至一些人为此付出了生命,机场鸟害防治工作日益受到人们的重视.文中从严峻的鸟害形势需要高素质的人才和鸟害防治教学培训需要专业的实践场所2个方面介绍了创建机场鸟害防治实验室的必要性,并从生物标本的展示与制作、上墙图表的设计与标绘、软件系统的开发与应用3个方面论述了机场鸟...     

基于视域剪裁的三维场景快速消隐算法

提出了一种基于视域剪裁的三维场景快速消隐算法。对于场景中每个物体,通过判断其最小闭包长方体是否和视域相交,以决定是否绘制此物体。在我们的算法中,视域被抽象成一个近似方锥。这种近似并不影响判断效果,而算法的逻辑得到了极大的简化,速度得到了很大提高。在每一次相交判断中,只需进行乘法和加法运算。因为此算法数据结构简单,可以和其他基于层次遮挡的消隐算法一起使用。由于算法逻辑简单,适合采用硬件实现。     

猪血制备丙种球蛋白的研究

讨论工厂制备丙种球蛋白的方法 ,所得制品绝大多数为IgG ,另有极少量IgM和IgA。并就盐析和DEAE -纤维素联合使用制备高纯度丙种球蛋白作了初步性的探讨 ,结果表明此方法制备的丙种球蛋白纯度相当高     

Hierarchical Bayesian Estimation of the Products Reliability Based on Zero-Failure Data

1　IntroductionThezero-failuredataresearchisanewfieldintherecentyears,butitisrequiredurgentlyinpracticalprojects,sotheworkhasmoretheoryandpracticalvalues.Fromthearticle[1]presenting,moreandmoreattentionispaidbyresearchersallovertheworldintheze-ro-fai...     

带有非线性边界条件强耦合半线性抛物方程组解的Blow-up性态

讨论了一类非线性边界条件强耦合并线性抛物方程组解的Ｂｌｏｗ－ｕｐ性态。