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91.
硅盐电池快速充电的试验与研究 总被引:2,自引:1,他引:1
根据电池快速充电的原理,对硅盐电池进行充电试验,提出适用于该电池5段恒流快速充电和定压补充充电的充电方案,并在各种控制参量的基础上,给出了实现这种充电过程的控制方法。 相似文献
92.
93.
本文对双极性电解槽作了比较透彻的分析,提出了表达双极性电解槽的合理,可靠的等效电路,找到了更精确计算损失电流的数学方法,并有初步的实验数据验证。 相似文献
94.
R. Nuccitelli 《Cellular and molecular life sciences : CMLS》1988,44(8):657-666
Summary Morphogenetic fields must be generated by mechanisms based on known physical forces which include gravitational forces, mechanical forces, electrical forces, or some combination of these. While it is unrealistic to expect a single force, such as a voltage gradient, to be the sole cause of a morphogenetic event, spatial and temporal information about the electrical fields and ion concentration gradients in and around a cell or embryo undergoing morphogenesis can take us one step further toward understanding the entire morphogenetic mechanism. This is especially true because one of the handful of identified morphogens is Ca2+, an ion that will not only generate a current as it moves, but which is known to directly influence the plasma membrane's permeability to other ions, leading to other transcellular currents. It would be expected that movements of this morphogen across the plasma membrane might generate ionic currents and gradients of both electrical potential and intracellular concentration. Such ionic currents have been found to be integral components of the morphogenetic mechanism in some cases and only secondary components in other cases. My goal in this review is to discuss examples of both of these levels of involvement that have resulted from investigations conducted during the past several years, and to point to areas that are ripe for future investigation. This will include the history and theory of ionic current measurements, and a discussion of examples in both plant and animal systems in which ionic currents and intracellular concentration gradients are integral components of morphogenesis as well as cases in which they play only a secondary role. By far the strongest cases for a direct role of ionic currents in morphogenesis is the polarizing fucoid egg where the current is carried in part by Ca2+ and generates an intracellular concentration gradient of this ion that orients the outgrowth, and the insect follicle in which an intracellular voltage gradient is responsible for the polarized transport from nurse cell to oocyte. However, in most of the systems studied, the experiments to determine if the observed ionic currents are directly involved in the morphogenetic mechanism are yet to be done. Our experience with the fucoid egg and the fungal hypha ofAchlya suggest that it is the change in the intracellular ion concentration resulting from the ionic current that is critical for morphogenesis. 相似文献
95.
陆金康 《复旦学报(自然科学版)》1995,(6)
在相对论磁化等离子体内,除库仑和感应电场力外,粒子间的感应磁场力相互作用将对广义玻耳兹曼方程中碰撞项有贡献.本文导出了这个碰撞项的解析表式. 相似文献
96.
三华特高压电网地磁感应电流分析计算 总被引:2,自引:2,他引:0
在相同感应地电场作用下,高电压等级输电线路的地磁感应电流(geomagnetically induced currents,GIC)比较大,交流特高压电网建设使我国电网增加了1 000 k V电压等级,综合考虑线路长度、单位阻值等GIC影响因素,准确计算我国1000k V特高压电网的GIC是重要研究课题。以我国三华特高压电网为例,只考虑1 000 k V电压等级网络,建立GIC模型,计算了东向及北向感应地电场情况下特高压电网变电站及输电线路的GIC。计算结果表明,我国特高压电网1 000 k V变电站中受GIC影响最大的变电站有锡盟,上海等特高压变电站;另外我国特高压电网输电线路中GIC规划计算数据偏大的有石家庄—济南线路和南阳—长治(晋东南)线路等,应引起电网公司对GIC灾害防治的重视。 相似文献
97.
Based on the law of mass conservation, a general three-dimensional diffusion equation of suspended sediment due to waves and
currents, adaptable to estuarial and coastal areas, is derived by decomposing the instantaneous velocities and concentrations
into three-different-time-scale components respectively. A three-dimensional suspended sediment diffusion equation adaptable
to actual calculations is available as the result of the parameterizations of turbulent diffusion term and wave diffusion
term. Different from the former diffusion equations, the influence of waves and currents on suspended sediment diffusion can
be simultaneously reflected in the newly derived equation. 相似文献
98.
提出一种基于相对幅值法的接箍深度识别方法.该方法利用计算机处理技术对接箍曲线应用相对幅度鉴别方法,自动跟踪识别接箍深度,尤其是能够自动跟踪识别受套管磁化干扰信号影响的接箍深度.该方法识别的接箍深度比使用简单的门限值,识别范围及最大值方法计算的接箍深度更准确,精度也更高,能够有效确定射孔作业深度,防止误射孔发生,为油田薄油层的开采提供技术保证,应用效果良好. 相似文献
99.
为明确不同磁程长度条件下磁化水对混凝土压拉性能的影响,用不同磁程长度磁化后的磁化水拌制混凝土,制作立方体试块进行压拉强度试验,研究磁化水混凝土压拉强度的变化规律;并对其机理进行分析。试验结果表明:磁程长度显著影响混凝土压拉强度的增幅;磁程长度不同时,混凝土28 d抗压强度增幅为4.72%~24.80%;28 d劈裂抗拉强度增幅为3.49%~17.05%;水被磁化过程中,存在最佳磁程长度,在磁感应强度B=260 m T,水流速度V=0.8 m/s时,最佳磁程长度L=360 mm,此时磁化水混凝土压拉性能改善最显著。磁化水对混凝土早期强度提高更明显。 相似文献
100.
北部湾及广西近海潮流数值模拟 总被引:1,自引:0,他引:1
该文采用二维浅水模型模拟分析了北部湾海域潮流系统,并在此基础上建立了广西沿海一、二维耦合水动力模型,模型中考虑了广西沿岸6条主要入海河流对近岸水动力的影响,进一步分析了广西近海海域潮致余流场及其对近海污染物输移扩散的影响。模型潮位计算值和实测值符合良好。结果显示:K1分潮在北部湾口形成一个逆时针旋转潮波系统,M2分潮在湾顶越南海防附近形成逆时针旋转潮波系统,广西近海海域K1分潮占优。广西沿海海域内,离岸较近的海域余流场相对较强,余流速度受浅水效应及湾口等地形缩窄影响而增强;离岸较远海域余流明显减弱,水体交换能力降低。 相似文献