Oleuropein Inhibits LDL Oxidation Induced by Cooking Oil Frying By-products and Platelet Aggregation Induced by Platelet-Activating Factor

Oleuropein, a polyphenolic glucoside, constituent of olive fruit and oil, has been previously shown to exhibit, in vitro, potent properties as a biological antioxidant. In the present paper, two new properties are demonstrated in vitro as well, concerning its vascular protection activity, against the atheromatic lesion formation and its blood antithrombotic effect. Firstly, it was found that the oxidation of low-density lipoproteins (LDL), induced by different quantities of total polar materials (TPM), was inhibited by 10 μ M (final concentration) of oleuropein, revealing approx. 50% protection. Secondly, platelet-rich human plasma aggregation, induced by either the platelet-activating factor or adenosine diphospate or arachidonic acid, was inhibited by oleuropein. The 10 μ M (final concentration) of oleuropein was proven to be the most effective among the tested concentrations against LDL oxidation, while an IC₅₀=0.41 mM was calculated for its inhibitory activity against platelet aggregation induced by 0.7 μ M platelet-activating factor.     

GaN and AlGaN high-voltage rectifiers grown by metal-organic chemical-vapor deposition

In this paper, we report the study of the electrical characteristics of GaN and AlGaN vertical p-i-n junctions and Schottky rectifiers grown on both sapphire and SiC substrates by metal-organic chemical-vapor deposition. For GaN p-i-n rectifiers grown on SiC with a relatively thin “i” region of 2 μm, a breakdown voltage over 400 V, and forward voltage as low as 4.5 V at 100 A/cm² are exhibited for a 60-μm-diameter device. A GaN Schottky diode with a 2-μm-thick undoped layer exhibits a blocking voltage in excess of ∼230 V at a reverse-leakage current density below 1 mA/cm², and a forward-voltage drop of 3.5 V at a current density of 100 A/cm². It has been found that with the same device structure and process approach, the leakage current of a device grown on a SiC substrate is much lower than a device grown on a sapphire substrate. The use of Mg ion implantation for p-guard rings as planar-edge terminations in mesageometry GaN Schottky rectifiers has also been studied.     

STRESS INTENSITY FACTORS AND WEIGHT FUNCTIONS FOR SEMI-ELLIPTICAL SURFACE CRACKS IN FINITE-THICKNESS PLATES UNDER TWO-DIMENSIONAL STRESS DISTRIBUTION

Abstract— A Fourier series approach is proposed to calculate stress intensity factors using weight functions for semi-elliptical surface cracks in flat plates subjected to two-dimensional stress distributions. The weight functions were derived from reference stress intensity factors obtained by three-dimensional finite element analyses. The close form weight functions derived are suitable for the calculation of stress intensity factors for semi-elliptical surface cracks in flat plates under two-dimensional stress distributions with the crack aspect ratio in the range of 0.1 ≤ a/c ≤ 1 and relative depth in the range of 0 ≤ a/t ≤ 0.8. Solutions were verified using several two-dimensional non-linear stress distributions; the maximum difference being 6%.     

基于属性相关表的关系模式全部候选关键字求法

本文提出了属性相关表这样一种新的概念，定义了相应的运算并研究了它的有关性质及定理，在此基础上提出了用属性相关表求关系模式全部主属性的等级，并给出了用主属性来组合关系模式全部候选关键字的算法，上述算法的时间复杂度均为Ｏ（ｎ＾２）。     

水溶性防氧化剂在SMT用印制板上的应用

水溶性的防氧化剂是一种有机可焊性保护剂。其方法是在印制板完全阻焊、字符层的印刷，并经电检之后，通过表面浸渍在裸铜的贴片位或通孔内形成一种耐热性的有机可焊性膜层。这种有机、可焊、耐热的膜层，膜厚可达0.3-0.5mm，其分解的温度可达约300℃，传统的印制板的热风整平法亦无法满足QFP愈来愈密集的需求，同时也无法满足SMD表面平整度的要求，更无法适应PCB薄型化生产。烷基苯并咪唑的OSP法能弥补这项缺陷，因而在PCB业乃至SMT产业中得到了广泛的应用。     

水平井岩屑录井的影响因素及对策

由于岩屑沉积床的形成、井壁坍塌和井眼不规则、岩屑多次破碎、钻时资料失真及混油钻井液污染等因素影响，水平井的岩屑比普通直井更混杂、更细碎，代表性也更差，岩屑中的油气显示真假难辨。通过加密实测迟到时间，参考钻井参数及DC指数可以对岩屑进行较准确地分层、描述，采用多次荧光滴照、四氯化碳浸泡、气测资料分析等方法，能够有效地区分真假油气显示。     

地地战术导弹飞行可靠性指标评定方法

在小子样情况下 ,利用系统和分系统试验数据对导弹的飞行可靠性指标进行评定 ,从数学上说是系统可靠性综合问题 .运用MML SR方法对新型号地地战术导弹的飞行可靠性指标进行评定 ,避免了MML方法在遇到无失败单元时不适用的缺陷 ,在利用地面试验信息方面有其明显优势 ;运用Bayes方法对改进型导弹的飞行可靠性指标进行评定 ,将不同试验阶段的多源试验信息作为验前信息 ,扩大了信息量 .最后 ,对两种方法在工程应用上遇到的问题进行了讨论 ,并给出了解决方法 .     

分户计量供暖节能住宅户型修正研究

针对多层住宅中不同户型在耗热量上的差异，引入户型体形系数修正各户的计量用热量，以计算和实测方法分析了一栋节能住宅不同围护结构户型的能耗特点，发现山墙、屋面、地面造成的不同户型之间的耗热量差别小于传统建筑；使用面积大的住户山墙造成的户型间耗热量差别小于使用面积小的住户。     

SHAPE GENERALIZED ISOTHERMAL EFFECTIVENESS FACTOR FOR FIRST-ORDER KINETICS

A generalized effectiveness factor equation (Eq. (32)), in terms of modified Bessel functions, is derived for a catalyst pellet of arbitrary shape. The derivation is based on utilizing an appropriate one-dimensional approximation for the Laplacian in an arbitrary shaped body subjected to a uniform external concentration field. The comparison of the result with the available expressions for various geometries is highly satisfactory. It unifies the expressions for the three fundamental shapes, viz., infinite slab, infinite cylinder and sphere, and also compares very well with the exact solutions for finite shapes over the entire range of the Thiele modulus.     

组播通信的访问控制和密钥管理

IP组播是一种高效的多目标传输机制.随着网络的发展,组播在网络的应用占据着越来越重要的地位,其应用不断扩展,技术日益成熟.目前,组播作为一个崭新的学术研究领域,在组播路由算法、流量控制、可靠传输等方面的研究已有很多成果,而对于组播安全问题的研究特别是组播通信密钥的研究还很不成熟.本文通过研究绀播通信安全进行深入的研究,对比各种密钥管理方法,研究了可扩展的密钥管理方法.该密钥管理体系采用分层管理结构,采用子管理中心对各个子域进行管理,不仅可以高效地处理组播组成员动态加入和退出,同时,大大减少了密钥管理中心的负担.使该方法可以应用于大型、动态的组播系统.此外,该方法根据现有的网络和组播系统的要求,提出了控制中心由计算机组进行统一调度管理,避免了单点故障的问题,增加了系统的鲁棒性.