多硫化钼微网格电极的几何弹跳效应对析氢效率提高的研究

气泡的析出行为在电化学析气反应中具有重要作用.为了研究周期性结构对气泡脱离的影响,我们构建了一维线性构造的多硫化钼微网格电极.结果表明,利用该电极上的气泡融合行为释放出的表面能可诱导气泡弹起,从而实现气泡的快速脱离,消除气泡屏蔽效应.基于优选的40μm凹槽宽度,产生的气泡以融合的方式可使得脱附尺寸显著降低(体积减小65...     

基于Nios嵌入式处理器的片上可编程系统设计

Nios嵌入式处理器是用户可配置的通用RISC嵌入式处理器,是一个非常灵活和强大的处理器.随着PLD(可编程逻辑器件)性能的不断提高,SOPC(可编程片上系统)的设计和实现非常方便,用户可以灵活地进行系统硬件和软件设计,还可以现场进行系统级修改.文中结合实例,给出了基于Nios嵌入式处理器的SOPC软、硬件设计与实现方法.     

Heat and mass coupled transfer combined with freezing process in building materials: Modeling and experimental verification

Newly completed building envelope is always characterized by high initial moisture content, and so the liquid moisture permeability is the main feature of mass transferring on its initial use. The high initial moisture content has strong impact on indoor condition and energy consumption especially in severe cold area where the moisture freezing in building envelope would occur in winter. Therefore, accurately predicting the hygrothermal states of building envelope to obtain useful envelope parameters is very important. In order to analyze the moisture transferring performance of enclosure on building initial use in severe cold area, the paper studied the coupling transfer of heat and moisture in building envelope. The permeability and freezing of the liquid water in porous building material were considered. The moisture content gradient was used as mass transfer driving force, and the temperature gradient was used as heat transfer driving forces. Heat and moisture coupled transfer conservation equations on different transferring conditions were built. An experimental set-up was built to verify the model, and good agreements were obtained, which suggests that the model can be used to simulate the heat and moisture coupled transfer in newly completed building envelope of severe cold area.