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%.     

A new monitoring system for piping systems in fossil fired power plants

A CEC-funded project has been performed to tackle the problem of producing an advanced Life Monitoring System (LMS) which would calculate the creep and fatigue damage experienced by high temperature pipework components. Four areas were identified where existing Life Monitoring System technology could be improved:

1. 1. the inclusion of creep relaxation

2. 2. the inclusion of external loads on components

3. 3. a more accurate method of calculating thermal stresses due to temperature transients

4. 4. the inclusion of high cycle fatigue terms.

The creep relaxation problem was solved using stress reduction factors in an analytical in-elastic stress calculation. The stress reduction factors were produced for a number of common geometries and materials by means of non-linear finite element analysis. External loads were catered for by producing influence coefficients from in-elastic analysis of the particular piping system and using them to calculate bending moments at critical positions on the pipework from load and displacement measurements made at the convenient points at the pipework. The thermal stress problem was solved by producing a completely new solution based on Green's Function and Fast Fourier transforms. This allowed the thermal stress in a complex component to be calculated from simple non-intrusive thermocouple measurements made on the outside of the component. The high-cycle fatigue problem was dealt with precalculating the fatigue damage associated with standard transients and adding this damage to cumulative total when a transient occurred.

The site testing provided good practical experience and showed up problems which would not otherwise have been detected.     

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。     

保护储层的无固相压井液

研制出了具有保护储层效果的无固相压井液，其基液配方为0．5％LG－1－1＋0．4％LG－2＋1％小阳离子＋0．1％其它。此外还研究开发出了无机盐增溶剂LG－3，加入LG－3可加宽低成本无机盐的使用范围，很大程度地降低压井液配液成本和单井综合成本。该压井液密度在1．0－2．5g/cm^3之间可调，具有无固相、滤失量低、抑制性强等特点，抗温能力在120℃左右。室内性能评价结果表明，无固相压井液对高渗储层岩心的渗透率损害率平均为4．0％，对低渗储层岩心的渗透率损害率平均为2．9％，说明该体系对储层具有很好的保护效果。     

聚合物降解产物伤害与糖甙键特异酶破胶技术

综述了钻井，完井，尤其是水力压裂作业中产生的多糖类聚合物伤害和应用糖甙键特异酶破胶，解除多糖类聚合物伤害的技术。第一节报道了聚合物降解产物造成的伤害，指出冻胶破胶液粘度低并不代表压裂液已从充填裂缝中充分返排，氧化破胶剂和普通酶破胶剂不能使多糖类聚合物充分降解，产生的大分子量，水不溶的降解产物可对地层造成伤害，消除伤害的办法是采用对糖甙键有特异性的各种水解酶作压裂液破胶剂或伤害地层处理剂。第二节报道了各种聚合物（纤维素，瓜尔胶，淀粉）糖甙键特异酶降解聚合物的机理。第三节报道了糖甙键特异酶（主要针对瓜尔胶）的应用性能测试及结果，包括岩心流动实验，含糖量和分子量测定，传导性测试。第四节介绍了糖甙键特异酶消除聚合物伤害和用作压裂液破胶剂的现场应用，包括选井原则，实施工艺要点及3个典型井例。     

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。