The extraction,antioxidant and against β-amyloid induced toxicity of polyphenols from Alsophila spinulosa leaves

Alsophila spinulosa is a tree-like fern, and many evidences suggested that plant polyphenols had the potential therapeutic for Alzheimer s disease (AD). Herein, polyphenols (ASP) was isolated from A. spinulosa leaves and its major constituent were isoorientin and vitexin. ASP displayed excellent antioxidant activity and obvious anti-lipid peroxidation capacity in vitro. ASP improved the survival rate of C. elegans under high temperature by enhancing the antioxidant enzymes activities and decreasing the lipid peroxidation level. Moreover, ASP alleviated β-amyloid (Aβ) induced paralysis and reduced Aβ deposition, decreased reactive oxygen species (ROS) accumulation and improved the level of skn-1 mRNA. In addition, ASP decreased the levels of pdk-1 and akt-1 mRNA in P13K/AKT signaling pathway. In conclusion, ASP may be a potential ingredient for the alleviation of AD.     

Solubility of 1-Butene in Water and in a Medium for Cultivation of a Bacterial Strain

Solubility measurements of 1-butene in water, from 20 to 50°C and at atmospheric pressure, were carried out using a Ben-Naim/Baer-type apparatus. The experimental results have a precision of about ±0.3%. Using accurate thermodynamic relations, the Ostwald coefficients at the experimental conditions and at infinite dilution, the mole fractions of the dissolved gas at the gas partial pressure of 101.325 kPa and the Henry coefficients at the water vapor pressure were calculated. The mole fraction of dissolved gas were fitted to the Clarke, Glew, and Weiss equation and thermodynamic quantities, standard molar Gibbs energy, entropy, and enthalpy changes, for the process of transferring the 1-butene molecules from the gaseous to the water phase, were computed. Moreover, solubility measurements of 1-butene in an aqueous medium for the cultivation of Xanthobacter Py2 in the same temperature range were also performed at atmospheric pressure. These solubility data are approximately 2.6% lower than those observed in pure water.     

介质球面上极化电荷及空间电场分布规律

文章对置于匀强电场中的均匀介质球内和球外的电势和电场分布进行了定量的研究,同时讨论了ε1/ε2→0和ε1/ε2→∞时,介质球表面上极化电荷的分布规律及电势、电场分布。     

关于我国中小企业融资问题的思考

随着我国经济的发展，中小企业在经济建设中发挥着越来越重要的作用，而融资难已成为制约中小企业发展的重要因素之一。分析了我国中小企业融资难的现状及其成因，从我国国情出发，同时借鉴国外先进经验，提出了解决中小企业融资难的对策。     

清洁生产灰色层次评价模型在中小企业的应用

中小企业清洁生产的评价存在界限不确定性、评价指标难以量化等缺点。结合灰色系统理论,为清洁生产提出了灰色层次评价模型,并将其用于中小化学工业企业的评价过程,结果表明该模型能对清洁生产提供决策依据。     

基于ASP的中小企业信息化方案

我国中小企业信息化过程中普遍存在基础薄、资金少、人才缺乏等难题，因此传统的电子商务战略难以适应中小企业的需要、以“服务租用”理念为核心的应用服务提供商(ASP)模式能有效地解决上述难题．通过对ASP及其特点的介绍，详细分析了ASP模式在中小企业信息化中的优势，提出了一套适合中国中小企业的ASP解决方案。     

中厚板控制冷却数学模型

介绍了中厚板控制冷却过程中所用的数学模型,包括差分模型、空冷和水冷换热系数模型、比热和热传导率模型,并采用有限差分法模拟计算了钢板在冷却过程中厚度、宽度方向上的温度场分布,以及间歇冷却对控制冷却的影响·从模拟结果可以看出,返红时间、厚度上温度梯度随钢板厚度增加而增加;间歇冷却时钢板内部温度呈均匀下降,表面不断冷却与返红过程·在线应用证明该套数学模型计算精度较高,可以满足现场实际生产的要求·     

变形双重介质分形油藏渗流流动分析

研究了变形双重介质分形油藏渗流问题的压力不稳定响应 ,考虑了储层的双重介质特征和分形特征以及应力敏感地层中介质的变形问题 ,建立了新的应力敏感地层双重分形介质数学模型 ,包括只有裂缝发生形变和裂缝与岩石同时发生形变时定产量生产的两类数学模型。渗透率依赖于孔隙压力变化的流动方程是强非线性的 ,故采用数值方法求解了这些数学模型。探讨了分形参数、变形参数和双重介质参数变化时压力的变化规律 ,给出了典型的压力曲线图板。这些结果可用于试井分析。     

中小企业理论述评——兼论西部实施中小企业战略的可行性

本文从缝隙生存、交易成本和创业理论角度对中小企业存在合理性进行阐述 ,兼论西部实施中小企业战略的可行性     

以啤酒洗槽废水为主料产朊圆酵母液体发酵的研究

以啤酒洗槽废水为主料通过单因素优选和正交试验法对产朊圆酵母进行液体发酵培养基的筛选与发酵条件的确定，经方差分析结果最佳培养基为2^oBe糖度的啤酒洗槽废水，豆饼粉0.5%,葡萄糖2％，MgSOr.7H2O0.05%,KH2PO40.1%。最佳发酵条件为时间18h，温度28℃，转数150r/min，装量100mL/250mL三角瓶，pH5.0。干菌体系累量为20.12g/L。