蚓激酶提取条件的优化与酶活性测定

蚯蚓纤溶酶是目前较为理想的溶栓药物之一,具有广泛的临床应用前景。采用盐析法从蚯蚓中提取蚓激酶,通过采用考马斯亮蓝G-250染色法间接地测定蚓激酶活性,优化出最佳的提取条件。结果显示,蚓激酶的提取最佳PH为7.5-8.0,二次盐析硫酸铵饱和度应在80%以上。     

第三类边界条件一维波动问题解法

求解第三类边界条件波动、输运定解问题时,本征值方程总是超越代数方程,手工无法求解.而且本征函数序列不是周期函数序列,理论上定解问题不能严格求解.利用Mathematica编程,可以快速得到这类问题的近似解,而且近似解完全满足应用需要.以一维波动定解问题为例,展示第三类边界条件定解问题的求解思路和技巧.     

Existence for Second Order Semilinear Impulsive Delay Integrodifferential Equations with Nonlocal Conditions

A fixed point analysis approach is used to investigate the existence of mild solutions of second order semilinear impulsive delay integrodifferential equations with nonlocal conditions. Without imposin...     

一类非光滑B-(p,r)-规划问题的最优性条件

针对目标函数和约束函数是正则弱Lipschitz的非光滑规划问题,在一定的条件下,给出并证明了带有等式和不等式约束的非光滑B-(p,r)-规划问题的最优性条件,讨论了KKT条件与局部最优解之间的关系。     

Effect of storage conditions on long-term stability of Ag nanoparticles formed via green synthesis

Spherical Ag nanoparticles (AgNPs) with a diameter of 20 nm or smaller were biologically synthesized using algae Parachlorella kessleri. The effect of storage conditions on the long-term stability of AgNPs was investigated. UV/Vis spectrophotometry, transmission electron microscopy, and dynamic light scattering measurements revealed that the long-term stability of AgNPs was influenced by light and temperature conditions. The most significant loss of stability was observed for the AgNPs stored in daylight at room temperature. The AgNPs stored under these conditions began to lose their stability after approximately 30 d; after 100 d, a substantial amount of agglomerated particles settled to the bottom of the Erlenmeyer flask. The AgNPs stored in the dark at room temperature exhibited better long-term stability. Weak particle agglomeration began at approximately the 100th day. The AgNPs stored in the dark at about 5℃ exhibited the best long-term stability; the AgNPs stored under such conditions remained spherical, with a narrow size distribution, and stable (no agglomeration) even after 6 months. Zeta-potential measurements confirmed better dispersity and stability of AgNPs stored under these conditions.     

米曲霉A－9005产生酸性蛋白酶的适宜条件

本文研究了米曲霉Ａ－９００５产生酸性蛋白酶的适宜培养基和培养条件。培养基组成（％）为：玉米粉４，黄豆粉５，ＫＨ２ＰＯ４，０．１，ＫＮＯ３０．２，ＺｎＳＯ４０．００１，ｐＨ５，适宜培养温度为３１℃。在上述条件下于往返式摇床（１１０ｒ／ｍｉｎ）培养７２ｈｒ，发酵液的酶活力为８８８２．５μ／ｍｌ。     

基于SPSS的我国各省市经济状况的实证分析与探讨

随着经济的发展，传统的三大经济地带分类法已不能满足现状．本文通过选取除港、澳、台之外的31个省市为样本，基于能够综合反映经济状况的多个指标，采用SPSS中的聚类分析方法将所选样本分为三类经济区域，并分别进行讨论．     

n集函数极小极大分数规划的最优性充分条件

本文主要讨论了n集函数极小极大分数规划最优性问题.首先介绍了具有广义V不变凸的函数的概念,然后在这类广义凸性性质下证明n-集函数极小极大分数规划的最优性充分条件.     

浅谈高校图书馆网络化信息服务

介绍了网络空间的定义以及网络对高校图书馆的影响,比较了传统的高校图书馆信息服务、网络化的高校图书馆信息服务以及二者的特点,分析了高校图书馆网络信息服务的构建条件,提出了高校图书馆网络信息服务体系与创新.     

浮动密封在煤矿机械中应用的重要性

介绍了浮动密封的结构、密封机理、材质、性能及其应用,并对它的使用条件、使用范围和发展提出了一些看法。