固相萃取高效液相色谱-质谱法测定动物组织中硝基呋喃代谢产物

研究了对动物组织中4种硝基呋喃类代谢产物AOZ、AMOZ、SEM和AHD的自动固相萃取HPLC-MS分析方法，分别以2-氯苯甲醛和2-硝基苯甲醛作为衍生化试剂，分别用AMOZ-d5、AOZ-d4作内标，用ENSPE柱进行提取，以乙腈-0．1％甲酸为流动相，采用梯度洗脱，可在15min内将4种代谢产物完全分离并进行测定。回收率为85％-90％；检出限可达0．5μg／kg。采用两种衍生化方法可获得较多的定性确证信息。采用本方法研究了硝基呋喃在鸡饲养过程中的残留规律。     

ζ(2)=π2/6的几个证明

给出并介绍 ζ( 2 ) =π26的几个证明     

一阶迭代微分方程的解析解

讨论了一阶迭代微分方程解析解的存在性,通过构造一个辅助方程的幂级数解给出该方程的解析解.     

高效液相色谱法测定动物组织中磺胺类残留量

磺胺类合成抗菌药是一类抑制核酸合成的抗菌药，可分为全身应用、肠道应用和局部外用等3类。磺胺类药物作为预防与治疗用药而广泛地用于食用动物中。但有文献报道该类药物可能使小鼠致癌。同时，由于该类药品可残留在动物组织中，食用含有磺胺类药物残留的动物源性食品，可引起过敏、尿和造血紊乱等不良反应。目前中国、欧盟、美国、日本、韩国等国家均将磺胺类药物列为动物饲养过程中限制使用的药物，其最大残余限量一般为50～100μg／kg。本实验采用样品加入乙腈提取后，用乙腈饱和的正己烷去除脂肪和杂质，通过优化色谱条件，进行7种磺胺类药物多残留的同时测定。结果表明，本方法简便，快速，结果准确，适合大批量样品的测定。     

A delay-decomposition approach for stability of neural network with time-varying delay

This paper studies delay-dependent asymptotical stability problems for the neural system with time-varying delay.By dividing the whole interval into multiple segments such that each segment has a different Lyapunov matrix,some improved delay-dependent stability conditions are derived by employing an integral equality technique.A numerical example is given to demonstrate the effectiveness and less conservativeness of the proposed methods.     

Further improvement of the Lyapunov functional and the delay-dependent stability criterion for a neural network with a constant delay

This paper investigates the asymptotical stability problem of a neural system with a constant delay. A new delaydependent stability condition is derived by using the novel augmented Lyapunov–Krasovskii function with triple integral terms, and the additional triple integral terms play a key role in the further reduction of conservativeness. Finally, a numerical example is given to demonstrate the effectiveness and lower conservativeness of the proposed method.     

二阶非线性摄动微分方程的振动性定理

研究了一类二阶非线性摄动微分方程解的振动性,建立了两个新的振动性定理,推广和改进了已有的结果.     

Improvement on generalised synchronisation of chaotic systems

In this paper,the problem of generalised synchronisation of two different chaotic systems is investigated.Some less conservative conditions are derived using linear matrix inequality other than existing results.Furthermore,a simple adaptive control scheme is proposed to achieve the generalised synchronisation of chaotic systems.The proposed method is simple and easy to implement in practice and can be applied to secure communications.Numerical simulations are also given to demonstrate the effectiveness and feasibility of the theoretical analysis.