基体亲水ePTFE的复合质子交换膜

采用萘-钠法对ePTFE膜进行亲水处理,研究了萘钠自由基溶液处理ePTFE的机理及对ePTFE的亲疏水性的处理效果,探讨了ePTFE的亲水性对复合膜制备的影响.结果表明,萘钠自由基亲水化处理的实质是生成了-OH、-CO和-CH等基团.处理后的ePTFE的接触角由(137±0.5)゜变为(45±0.5)゜全氟磺酸树脂(PFSI)与ePTFE基体的结合能力增大.提高了PFSI的填充度,电池性能有所提高.     

直接甲醇燃料电池用磺化聚醚醚酮基复合膜

磺化聚醚醚酮(SPEEK)用N,N'-羰基二咪唑和氨基丙基三乙氧基硅烷进行预处理后,与原硅酸四乙酯和经三乙醇胺溶液处理过的α-磷酸氢锆由sol-gel法制得有机/无机复合膜,并对其进行了傅里叶变换红外光谱(FTIR)、表面形貌、甲醇透过性和DMFC极化曲线的研究.复合膜有比SPEEK膜低的甲醇渗透系数和溶胀,由复合膜组装的直接甲醇燃料电池有比Nafion117膜高的开路电压,最高比功率达到15 mW/cm2.     

Rectification in biological membranes

Rectification in biological membranes is discussed in terms of four models: simple electrodiffusion based on the constant field approximation, without and with surface charge on the inner side of the membrane; a channel with an energy barrier; and a voltage-gated channel. The current-voltage relations are derived for simplified cases and the rectification characteristics analyzed and compared     

Reactance of biological membranes

Discusses the reactance of a voltage-gated channel that obeys first-order kinetics, where the current-voltage characteristic is derived and linearized at an arbitrary quiescent point. It is shown that the reactance is inductive in the high-conductance region of the characteristic, where the incremental conductance is larger than the chord conductance; that the reactance is capacitive in the low-conduciance region, where the incremental conductance is smaller than the chord conductance; and that the reactance vanishes at the equilibrium potential. The values of the elements of the equivalent circuit are derived as a function of membrane voltage and parameters, and some general aspects of the reactance of biological membranes are discussed     

Composite resonant switches

Main types of zero-current and zero-voltage composite resonant switches are described. Their basic properties and characteristics are analyzed. It is shown that the use of these switches ensures soft switching conditions for all switching elements of the circuit, including the primary, antiphase, and auxiliary ones.     

复合横担用复合法兰设计研究

为了缩短复合横担、降低塔重和压缩走廊宽度,提出采用复合法兰取代常规的钢制节点,实现复合横担节点复合化。通过试验研究和有限元仿真分析,研究了复合法兰的受力性能,结果表明,复合法兰承载能力可满足一般750 kV线路工程的要求。