微波消化石墨炉原子吸收法测定动物组织中的微量铝

采用微波消化测定动物组织中微量的铝。先用硝酸高压溶解，然后用石墨炉原子吸收测定。方法的检出限0．91ng／ml，线性范围0—1000ng／ml，其回收率为95．1％-104．7％．该方法简化了对动物组织中铝测定的消化，精密度高，检出限低。     

微波消解-氢化物发生-原子荧光光谱法同时测定食品中的As和Hg

应用微波消解-氢化物发生-原子荧光光谱法测定食品中微量砷(As)和汞(Hg)的含量,实验结果表明,在最佳条件下,该法的回收率分别是:砷为94.5%～101%,汞为92%～96%,相对标准偏差值为1.0%～1.66%,As和Hg的检出限分别为0.1μg·L-1和0.02μg·L-1,其线性范围分别为1.0～100μg·L-1和0.2～60μg·L-1.该法能满足各类食品中微量砷和汞含量的测定要求,具有分析速度快、操作简便、检验效率高等特点.     

地方政府对产业集群的促导机制和效应解析

产业集群的培育与发展如同森林的栽植 ,其关键是根据自然条件与树种特性 ,相互选择 ,并精心呵护。因此 ,政府在培育和发展产业集群的进程中具有不可替代的促导作用 ,本文从产业集群的内涵和形成方式入手 ,对地方政府在产业集群中扮演的促导角色、发挥这一角色的机制和效应进行了系统的分析。     

聚类分析法在大气环境质量评价中的应用

大气环境质量评价工作是一项重要但又复杂的工作,用传统方法很难准确判断。用聚类分析方法来处理这一类问题,可得出综合、客观、准确的结论。文章对这一方法在国内大气环境质量现状评价中的应用进行了综述。     

High-Performance Broadcasting Algorithms on Cluster

In many clusters connected by high-speed communication networks, the exact structure of the underlying communication network and the latency difference between different sending and receiving pairs may be ignored when they broadcast, such as in the approach adopted by the broadcasting method in MPICH，a widely used MPI implementation. However, the underlying network cluster topologies are becoming more and more complicated and the performance of traditional broadcasting algorithms, such as MPICH‘s MPI_Bcast, is far from good. This paper analyzed the impact of communication latencies and the underlying topologies on the performance of broadcasting algorithms for multilevel clusters. A multilevel model was developed for broadcasting in clusters with complicated topologies, which divides the cluster topology into many levels based on the underlying topology. The multilevel model was used to develop a new broadcast algorithm，MLM broadcast-2 (MLMB-2), that adapts to a wide range of clusters. Comparison of the performance of the counterpart MPI operation MPI_Bcast and MLMB-2 shows that MLMB-2 outperforms MPI_Bcast by decreasing the broadcast running time by 60%-90%.     

Combined-dynamic mode “dip-pen” nanolithography and physically nanopatterning along single DNA molecules

Atomic force micriscope (AFM)-based dip-pen nanolithography (DPN) is an emerging approach for constructing nanostructures on material surfaces such as gold, silicon and silicon oxide. Although DPN is a powerful technique, it has not shown its ability of direct-writing and patterning of nanostructures on surfaces of soft materials, for example biomacromolecules. Direct depositing on soft surfaces becomes possible with the introduction of a combined-dynamic mode DPN rather than mostly used contact mode DPN or tapping mode DPN. In this report, the combined dynamic mode DPN is used for direct depositing protein ink on DNA molecules at the nanometer scale.     

基于群集技术的电子政务系统的设计与实现

电子政务是借助电子信息技术而进行的政务活动．要保证电子政务持续的运作和成功，就要保护基于计算机的信息．从服务器的群集技术、数据的备份、异地容灾几方面来构架安全的网络系统，最后实现了基于服务器群集技术的电子政务系统。     

一种异构机群系统管理软件模型及其关键技术

机群系统管理软件是机群系统管理员管理和监控整个机群状态的有力工具,给出了异构机群系统管理软件(HCSMS)的一种构建模型,分析该模型的组织结构,以及实现技术路线。提出了系统管理虚拟命令的统一和远程管理两项异构机群系统管理关键技术的解决方案。通过实用性能测试,表明该方案对异构机群管理有效。     

目标函数聚类法的适用性分析

以基于模糊c—划分的聚类方法为基础，针对影响目标函数聚类法聚类效果的主要因素，分别从5个主要方面作了聚类算法的适用性分析。     

FAAS测定汽车尾气催化剂中的铑

采用火焰原子吸收(FAAS)法对汽车尾气净化催化剂中贵金属铑(Rh)的含量进行了分析.为避免共存元素N i的谱线干扰,选择Rh的次灵敏线369.2 nm作为分析线,采用标准加入法定量、有效地消除了基体元素对测试结果的影响.催化剂样品分析相对标准偏差(RSD)为1.8%~2.7%,加标回收率为102.9%~104.7%.