颗粒表面改性法制备PTC粉体的研究

本文介绍了一种通过液相颗粒表面改性技术添加二次掺杂物来制备ＰＴＣ粉体的新方法。即将烧结助熔剂Ａｌ２Ｏ３，ＳｉＯ２以及受主杂质ＭｎＯ采用溶液形式，包裹在ＢａＴｉＯ３基粉体颗粒表面进行改性，由此可以得到二次掺杂物Ａｌ２Ｏ３、ＳｉＯ２和ＭｎＯ分布均匀的ＰＴＣ粉体。     

砼受压损伤力学本构模型的研究

本文利用ＭＴＳ公司８１５．０２型电液伺服试验系统对砼进行了等应变速率加载控制的应力一应变全曲线试验，应用不可逆热力学和内变量理论的成果建立了砼损伤力学模型，并用概率统计的观点分析了损伤的演化规律。由于考虑了不可逆变形的影响，本文所建本构模型与实验吻合较好。     

考虑环境影响的水电站水库模糊优化调度模型及其应用

本文在提出一种水电站水库优化调度准则的基础上,建立了考虑环境因素影响的水电站水库模糊优化调度模型,实例研究表明,所建模型是有效的、适用的。     

Ultrasonic evaluation of environmental durability of adhesive joints

An angle-beam ultrasonic technique is used to investigate the interfacial properties of lap shear adhesive joints subjected to severe environmental degradation under load. The mode of failure during the process of degradation changes from cohesive (through the bulk adhesive) to predominantly interfacial (along the adhesive/adherent interface). It is found that the minimum shift in the frequency spectrum of the reflected ultrasonic signal is more sensitive to changes of properties in the interphasial region than in the bulk adhesive. The shift of the minimum to lower frequencies is related to the fraction of interfacial failure area and to the joint strength. This could lead to a methodology for predicting the residual lifetime of the joint in service. The joint degradation is described by a mathematical model of an adhesive joint with nonhomogeneous interphase structure. Reasonable agreement between the experimental results and computer simulations on the basis of the proposed model is obtained.     

北京谱仪Ⅱ（BESⅡ）顶点探测器数据获取系统

北京谱仪（ＢＥＳⅡ）顶点探测器数据获取系统是北京谱仪数据获取系统的一部分，该子系统电子学采用快总线标准，本文描述了该系统的硬件结构和软件系统，软件包括快总线系统的微码软件和上层控制软件，该系统的死时间为１．５ｎｓ，对ＢＥＳⅡ系统总死时间的贡献小于０．５ｍｓ。     

Ginkgolides antagonizing some effects of platelet-activating factor in vitro

The mixture of platelet-activating factor (PAF) and platelets produced significant contraction of guinea pigs' bronchus, while the contraction induced by PAF alone was mild relatively, the IC50 were 6.14 x 10(-7) mol/L and 6.32 x 10(-4) mol/L respectively. There was significant difference between these two groups (P < 0.05). When the platelets were pre-incubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, effects of the PAF and platelets mixture were significantly inhibited (P < 0.01). Exposure of guinea pigs' bronchus to PAF in vitro resulted in a loss of beta-adrenergic receptors and responses to isoproterenol, and this effect of PAF was prevented by prior incubation of the guinea pigs' bronchus with ginkgolides (P < 0.05). The results showed ginkgolides were a potent PAF antagonist.     

重金属污染物动态吸附试验及数学模拟

本文采用泥沙动力学中Ｒｏｕｓｅ等人用来研究泥沙浓度沿垂线分布的装置。对泥沙吸附重金属污染物进行了动态模拟。试验分有底泥和无底泥两种情况。研究中发现在Ｒｏｕｓｅ装置的水力、泥沙条件下泥沙吸附重金属污染物达到平衡状态需要６小时以上，由极坐标下的重金属迁移转化数学模型方程，在本文具体试验条件下进行数值求解，计算结果和试验结果合良好，说明数学模型是正确合理的试验是可靠的。计算时依据室内静态试验结果，对动态