Narcotic antagonism of seizures induced by a dopamine-derived tetrahydroisoquinoline alkaloid

Summary This paper describes experiments designed to evaluate whether the narcotic antagonist naloxone significantly interferes with seizures induced by tetrahydroisoquinolines (TIQs). In these experiments we found that naloxone significantly reduced seizure scores induced by intra-cranially infusing mice with 50 g of the dopamine-derived tetrahydroisoquinoline (TIQ) alkaloid, 6,7-dihydroxy TIQ. These findings support an opioid involvement in the actions of TIQs and may lead to further understanding of opioid-mediated novel excitatory receptors.     

The physiology of the smooth muscle: an interdisciplinary review—part II

Summary In the guinea pig taenia coli, when glycogen is depleted by repeating Ca-induced contracture in excess K solution containing no glucose, the tension cannot be maintained. The decrease in tension is accompanied by reduction of high energy phosphate compounds and oxygen consumption. When substrate is readmitted to the glycogendepleted preparation in the presence of 2.4 mM Ca and 20 mM K, the first response is hyperpolarization of the membrane and relaxation, and this is followed by depolarization and development of contracture. The latter response is blocked by verapamil, suggesting that energy supply increases the Ca conductance of the plasma membrane. The early response is considered to be due to activation of electrogenic Ca pump, since this is not affected by ouabain as well as removal of Na and K. ATP produced by substrate readmission is probably preferentially utilized for Ca pump activation to reduce the intracellular. Ca. The recovery of tension is likely to be brought about by ATP supply not only to the contractile machinery but also to the plasma membrane to remove inactivation of Ca conductance. It is postulated that as the energy source is depleted, energy consumption is automatically limited by suppressing Ca influx, as a selfdefence mechanism. Since HB is as effective as glucose in the recovery of these processes, and also in the activation of electrogenic Na pump, the matabolic pathway of oxidative phosphorylation alone can support these functions without a contribution of the glycolytic pathway.     

三相电压型SVPWM整流器控制策略研究

提出了一种便于数字实现的三相电压型PWM整流器控制方案,该方案基于矢量控制的思想,采用输入电压空间矢量定向,结合直接电流控制的方法进行电流跟踪控制,提高了整流器的整体性能,仿真结果证明了该方案的有效性.     

激励方式中的“手铐”--股票期权

股票期权作为激励方式中的“手铐”，将激励与约束很好地结合在一起，实现了经理人和股东利益实现渠道的一致性，作为一种长期的激励机制．实现了公司治理的帕累托改进，股票期权在中国的应用，有积极的一面，但也有其局限性。     

超高产水稻协优9308的高效光合功能

比较研究了具有超高产潜力的水稻品种协优9308及对照品种汕优63的光能吸收、转化和利用．结果表明，超高产水稻的叶绿素和类胡萝卜素的含量均高于汕优63，吸收光谱结果也表明超高产水稻叶绿体具有更强的光能吸收能力；其叶片PSⅡ光能转化效率(Fv／Fm)，光化学猝灭(qp)及量子效率(ΦPⅡ)均高于对照，而超高产品种的非光化学猝灭(qv)则低于对照品种；Mg^2 对超高产水稻叶绿体PsⅠ和PsⅡ之间激发能分配的调节能力高于对照品种．光合电子传递活性及RuBPCase活性和含量也均高于对照．协优9308叶片较高的光能吸收、转化和利用可能是其实现超高产的重要原因之一．     

电力系统电压稳定性的Matlab建模分析

电力系统的仿真可以帮助人们通过计算机手段分析实际电力系统的各种运行情况,Matlab软件作为一个重要的工具,凭借其功能的全面性和专业性,得到了电力工作者的认可,但是进行具体电力系统动态行为分析时,存在建模困难等实际弱点,所以提出利用Matlab软件中的状态方程模块建立了一种经过简化的发电机和电动机的三阶模型,使得电机模型建立方便,而且容易与系统主要参量即电压和频率进行接口,并且利用Simulink建立了含发电机、输电线路、电动机、静止无功补偿器的典型的电力系统,在建模过程中为了使模型物理概念明确,针对经典的模型进行了必要的简化.通过故障仿真得出了相关的电压稳定性方面的结论,从而证明了这种简化模型的正确性和在分析应用中的可行性.     

数学形态滤波的电器瞬动保护算法

配电网出现单相接地故障时,故障相会出现大短路电流.智能电器要求在出现大短路电流情况下尽快启动瞬动保护,清除故障.但目前瞬动保护算法难以保证在各种短路情况下都能快速清除故障,保护重要负荷.本文对智能电器的瞬动保护算法进行了研究,提出了基于数学形态学(MM)滤波的瞬动保护算法,该算法先用级联数学形态滤波器对短路电流信号进行滤波,有效滤除了故障信号中的非周期分量和高频分量,滤波后用快速求导算法计算短路电流的有效值.算法简洁快速,兼顾瞬动保护的快速性和可靠性、不但有效地保护了线路和负荷,而且能缩短短路引起的电压暂降的持续时间,减少了短路造成的经济损失.     

基于脱扣力的低压断路器连杆机构优化设计

在对低压断路器的连杆机构进行机构分析和受力分析的基础上,以脱扣力为优化目标,以单一变量为约束条件进行初步优化运算,根据初步优化结果选择了多变量约束条件并确立了优化模型,采用复合形法对连杆机构进行了优化设计,脱扣力比原设计有较大幅度的下降。计算结果表明,优化模型建立正确,优化方法选择适当,对于提高低压断路器的工作质量具有指导意义。     

无功补偿装置投切过程的仿真研究

对采用晶闸管或晶闸管并联磁保持继电器的无功补偿装置的投切过程进行了仿真研究.结果表明,根据电容器接线特点,选择适当的投切时间,可降低晶闸管的承受电压,有利于无功补偿装置可靠运行.     

电力系统电压薄弱点的快速寻求法

讨论了电力系统潮流雅可比矩阵最小模特征值与系统电压静态稳定性的关系,将最小模特征值定义为电压稳定裕度,在此基础上定义了电压稳定裕度对控制变量的灵敏度和PQ节点负荷灵敏度,用以找出对系统电压稳定性造成影响的因素和寻找系统电压薄弱点,同时给出了它们的算法。最后通过WSCC 9节点系统仿真计算验证其有效性。