Design and characteristics of quantum cascade laser-based CO detection system

National High Technology Research and Development Program of China 2007AA03Z112；Program of Ministry of Education of China 20060183030；Program of Jilin Provincial Science and Technology Department of China 20070709；Program of Bureau of Science and Technology of Changchun City 2007107

Dual Confocal Laser-Induced Fluorescence/Moveable Contactless Conductivity Detector For Capillary Electrophoresis Microchip

A new dual simultaneous detector was developed for capillary electrophoresis microchip. Confocal laser-induced fluorescence (LIF) and moveable contactless conductivity detection (MCCD) were combined together for the first time. The two detection systems shared a common detection cell and could respond simultaneously. They were mutually independent and advantageous in analyses of mixtures containing organic and inorganic ions. The confocal LIF had high sensitivity and the MCCD could move along the separation channel and detect in different positions of the channel. The detection conditions of the dual detector were optimized. Rhodamine B was used to evaluate the performance of the dual detector. The limit of detection of the confocal LIF was < 5 nM, and that of the MCCD was 0.1 mu M. The dual detector had highly sensitivity and could offer response easily, rapidly and simultaneously. 

Dual confocal laser-induced fluorescence/moveable contactless

A new dual simultaneous detector was developed for capillary electrophoresis microchip. Confocal laser-induced fluorescence (LIF) and moveable contactless conductivity detection (MCCD) were combined together for the first time. The two detection systems shared a common detection cell and could respond simultaneously. They were mutually independent and advantageous in analyses of mixtures containing organic and inorganic ions. The confocal LIF had high sensitivity and the MCCD could move along the separation channel and detect in different positions of the channel. The detection conditions of the dual detector were optimized. Rhodamine B was used to evaluate the performance of the dual detector. The limit of detection of the confocal LIF was <5 nM, and that of the MCCD was 0.1 μM. The dual detector had highly sensitivity and could offer response easily, rapidly and simultaneously.

密码协议的一种安全模型

将密码协议与密码算法视为一个系统,建立了密码协议系统的一种安全模型.基于假设/保证的组合推理技术提出了新的假设/保证推理规则和假设/保证推理算法,证明了该规则的完备性,实现了密码协议系统的模型检查,并重点解决了系统分解问题、假设函数的设定问题、进程+逻辑的系统特性描述问题等难题.以kerberos密码协议系统为例,利用该安全模型和假设/保证推理技术对密码协议系统进行了安全验证.

基于基因规划的主机异常入侵检测模型

异常检测技术假设所有的入侵行为都会偏离正常行为模式.尝试寻找一种新的异常入侵检测模型改善准确性和效率.模型利用应用程序的系统调用序列,通过基因规划建立了正常行为模式.模型的一个例程管理一个进程.当它发现进程的实际系统调用序列模式偏离正常的行为模式时,会将进程设标记为入侵,并采取应急措施.还给出了基因规划的适应度计算方法以及两个生成下一代的基本算子.通过与现有一些模型的比较,该模型具有更好的准确性和更高的效率.

基于模糊行为分析的移动自组网入侵检测

移动自组网络是一种不需要基础设施的网络．在这种网络中，移动节点是自组织的，并且需要互相提供网络路由服务．自组网络非常容易受到攻击，特别是内部攻击．提出了一个基于模糊行为分析的入侵检测方案，以检测网络内部的路由攻击．利用邻接节点监测，通过分析节点路由行为与路由规范的偏差，发现恶意行为．在数据分析的过程中引入了模糊路由行为分析的方法，大大降低了误报率．仿真实验表明，该方案能有效地检测出路由入侵行为，而将误报率控制在一个较低的水平．

一种基于移动代理自动优化的分布式入侵检测系统

随着网络技术的飞速发展，网络入侵检测系统需要处理大量的数据，处理能力的缺乏会引起入侵事件的漏报或误报，提高入侵检测系统的处理能力是目前急需解决的关键问题．AODIDS是一个由移动代理作为优化组件、多个分析结点及探测结点组成的可自动进行优化的分布式网络入侵检测系统．AODIDS的优化组件执行系统的性能评估，制定相应的优化策略，在规定的系统检测正确率的前提下平衡分配网络流量，从而尽可能地发挥整个系统的处理能力．

基于进程行为的异常检测模型

利用系统漏洞实施攻击是目前计算机安全面临的主要威胁.本文提出了一种基于进程行为的异常检测模型.该模型引入了基于向量空间的相似度计算算法和反向进程频率等概念,区分了不同系统调用对定义正常行为的不同作用,提高了正常行为定义的准确性;该模型的检测算法针对入侵造成异常的局部性特点,采用了局部分析算法,降低了误报率.

一种基于Agent的自适应的分布式入侵检测系统

针对传统分布式入侵检测系统组件之间依赖程度大、系统不够健壮且入侵检测系统自身结构固定不能适应入侵的变化的问题,提出了一种基于Agent的自适应的分布式入侵检测系统(简称AAA-DIDS)·AAADIDS采用Agent概念重新构造系统的组件,改进了分布式入侵检测系统由于高层节点单一无冗余而产生的可靠性差的缺陷,从构造上克服了分布式入侵检测系统的脆弱性·同时,AAADIDS系统采用智能技术构建了自适应的入侵检测系统模型,增加了系统应对入侵行为变化的智能性·AAA-DIDS系统相对于传统的分布式入侵检测系统有效地提高了系统自身的可靠性和针对外界变化的适应能力·

Separation of ternary systems of hydrophilic ionic liquid with miscible organic compounds by RPLC with refractive index detection

A rapid and simple analytical method was developed for the simultaneous and quantitative determination and separation of hydrophilic imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium chloride, [C(4)mim]Cl; 1-hexyl-3-methylimidazolium chloride, [C(6)mim]Cl; 1-octyl-3-methylimidazolium chloride, [C(8)mim]Cl; 1-allyl-3-methylimidazolium chloride, [Amim]Cl; or 1-allyl-3-methylimidazolium bromide, [Amim]Br) with miscible ethyl acetate and EtOH and their mixtures using reverse phase liquid chromatography coupled with refractive index detection (RPLC-RI). The influence of 60 to 100% (volume percentage) methanol in the mobile phase on the IL systems ([C(4)mim]Cl, [C(6)mim]Cl, [C(8)mim]Cl, [Amim]Br, or [Amim]Cl)-ethyl acetate-EtOH was investigated.

Simultaneous Laser-Induced Fluorescence And Contactless-Conductivity Detection For Microfluidic Chip

A combined detection system involving simultaneous LIF and contactless-conductometric measurements at the same place of the microfluidic chip was described. The LIF measurement was designed according to the confocal principle and a moveable contactless-conductivity detector was used in (CD)-D-4. Both measurements were mutually independent and advantageous in analyses of mixtures. Various experimental parameters affecting the response were examined and optimized. The performances were demonstrated by simultaneous detection of Rhodamine B. And the results showed that the combined detection system could be used sensitively and reliably. (C) 2008 Yong Yu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Detection and quantitative analysis of polychlorinated biphenyls in tilapia from Hawaiian waters

The purpose of this study was to investigate polychlorinated biphenyls (PCBs) contamination in tilapia (Oreochromis mossambicus) collected from the Manna stream and Ala Wai Canal of O'ahu, an island of the geographically isolated Hawaiian archipelago. Our results show that the average concentrations of PCBs varied from 51.90 to 89.42 ng g(-1) lipid weight for the sampling sites. Relative toxic potencies (RTPs) and toxic equivalencies (TEQs) were determined to be 20.38-40.60 ng TCDD g(-1) lipid weight and 2.89-4.17 ng TEQ g(-1) lipid weight by 7-ethoxy-resorufin-O-deethylase (EROD) activity analysis and calculation of PCB concentrations based on toxic equivalency factors (TEFs), respectively. Penta-chlorinated congeners were found to be predominant, which revealed that Aroclor 1254 was a possible major source of PCBs in our fish samples. PCB 118, an indicator PCBs, constituted more than 55% and 30% of the total PCBs and TEQs, respectively. In addition, PCB 118 was found to have a linear correlation to the total PCBs (R = 0.975) and TEQs (R = 0.782). Detection of concentrated PCBs in Hawaiian waters suggests a potentially adverse impact of this pollutant on human health, as well as ecological systems, and suggests the necessity of environmental monitoring and hazard assessment of PCBs within the Hawaiian Islands. (c) 2008 Published by Elsevier Ltd.