高效液相色谱法测定中党参中4种黄酮类物质的含量

黄酮类化合物广泛存在于中药等植物体中,对人体肿瘤、衰老、心血管等退行性疾病的治疗和预防有重要意义~([1]).目前测定黄酮类物质的方法很多~([2～5]),本研究采用高效液相色谱法测定了党参中芦丁、曲克芦丁、黄芩苷和槲皮素4种黄酮成分的含量.方法简单易行,结果准确可靠.     

镧掺杂的介孔分子筛的合成及其光学性能研究

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,正硅酸乙酯(TEOS)为硅源,采用水热晶化法,合成了镧掺杂的MCM-41介孔分子筛。通过X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、透射电镜(TEM)、紫外-可见(UV-Vis)光谱等测试手段对其孔结构和镧原子的存在状态进行了表征。XRD和TEM结果表明,合成样品具有典型的二维六方有序介孔结构,样品的傅里叶变换红外光谱和紫外-可见光谱表明镧被成功的引入到介孔骨架中。     

高功率激光器MOPA相干合成系统分析

输出功率和光束质量一直以来都是高功率激光器的两大技术难点。本文采用并联主振荡-功率放大(MOPA)相干合成方法来提高输出光束的功率和光束质量。建立多级MOPA相干合成系统模型,通过计算分析,得到耦合效率、合成效率对合成功率密度及系统输出功率大小的影响;并对模型略加扩充,得到相位偏差对相干合成功率密度的影响,为高功率激光器的设计提供依据。     

Nonlinear consensus protocols for multi-agent systems based on centre manifold reduction

Nonlinear consensus protocols for dynamic directed networks of multi-agent systems with fixed and switching topologies are investigated separately in this paper. Based on the centre manifold reduction technique, nonlinear consensus protocols are presented. We prove that a group of agents can reach a β-consensus, the value of which is the group decision value varying from the minimum and the maximum values of the initial states of the agents. Moreover, we derive the conditions to guarantee that all the agents reach a β--consensus on a desired group decision value. Finally, a simulation study concerning the vertical alignment manoeuvere of a team of unmanned air vehicles is performed. Simulation results show that the nonlinear consensus protocols proposed are more effective than the linear protocols for the formation control of the agents and they are an improvement over existing protocols.     

Automatic generation of min-weighted persistent formations

This paper researched into some methods for generating min-weighted rigid graphs and min-weighted persistent graphs. Rigidity and persistence are currently used in various studies on coordination and control of autonomous multi-agent formations. To minimize the communication complexity of formations and reduce energy consumption, this paper introduces the rigidity matrix and presents three algorithms for generating min-weighted rigid and min-weighted persistent graphs. First, the existence of a min-weighted rigid graph is proved by using the rigidity matrix, and algorithm 1 is presented to generate the min-weighted rigid graphs. Second, the algorithm 2 based on the rigidity matrix is presented to direct the edges of min-weighted rigid graphs to generate min-weighted persistent graphs. Third, the formations with range constraints are considered, and algorithm 3 is presented to find whether a framework can form a min-weighted persistent formation. Finally, some simulations are given to show the efficiency of our research.     

Generalized LMI-based approach to global asymptotic stability of cellular neural networks with delay

A global asymptotic stability problem of cellular neural networks with delay is investigated. A new stability condition is presented based on the Lyapunov-Krasovskii method, which is dependent on the amount of delay. A result is given in the form of a linear matrix inequality, and the admitted upper bound of the delay can be easily obtained. The time delay dependent and independent results can be obtained, which include some previously published results. A numerical example is given to show the effectiveness of the main results.     

可折叠航天结构展开动力学分析

以欧拉参数为广义坐标（准坐标）,相对角速度和相对移动速度为广义速率,采用Ｋａｎｅ方程的Ｈｕｓｔｏｎ形式建立多体系统的运动力学方程。由伪上三角分解求约束Ｊａｃｏｂｉ矩阵的正交补阵,约简约束力,从而将运动方程由微分几何方程（ＤＡＥ）变为常微分方程（ＯＤＥ）,并由Ｇｅａｒ法对ＯＤＥ积分求出运动历程。最后给出一伸展臂数值分析算例。     

抑制型离子色谱法测定白酒中的F-、Cl-、NO2-、H2 PO4-、NO3-

用抑制型离子色谱法测定白酒中的F^-、Cl^-、NO2^-、H2PO4^-、NO3^-。流动相为4mmol／LNa2CO3—3 mmol／LNaHCO3混合溶液,流速为1．5mL／min,进样量为0、5mL,在最佳色谱条件下,5种无机阴离子10min内实现基线分离。F^-、Cl^-、NO2^-、H2PO4^_、NO3^-的检出限分别为0、008、0．012、0、030、0．068、0．077mg／L。测定结果的相对标准偏差分别为1．86％、1．30％、2．06％、1．82％、1．50％,回收率分别为108．0％、94．0％、101．0％、98．7％、94．4％。     

面包酵母在催化不对称合成中的应用

介绍了当前国内外在以面包酵母为催化剂不对称催化合成手性化合物的研究情况,重点介绍了面包酵母催化各类潜手性羰基的不对称还原、潜手性碳一碳双键的不对称加成和碳一碳键形成的反应情况,讨论了各种提高酵母催化不对称合成反应立体选择性的方法,对酵母催化不对称合成有关生物学方面的研究进行了简单的介绍。     

抑制型离子色谱法测定蔬菜中的NO2-和NO3-

用抑制型离子色谱法定量测定了NO2-和NO3-.两种阴离子在最佳色谱条件下,8 m in内达到基线分离.对于NO2-,检出限为0.002 mg/L,相对标准偏差为2.58%,线性范围0.2 mg/L~20 mg/L,相关系数0.999 6.对于NO3-,检出限为0.011 mg/L,相对标准偏差为2.01%,线性范围0.3 mg/L~30 mg/L,相关系数0.999 2.该法用于蔬菜中NO2-和NO3-的测定,结果良好.