Preparation and characterization of directional conducting and lower methanol permeable ultrathin membrane based on poly (vinyl alcohol) and imidazolium compounds

To produce directional conducting and lower methanol permeable ultrathin membrane for fuel cell, the imidazolium salt as both cross-linking agent and proton donor has been designed to build a directional proton conducting channel in a poly (vinyl alcohol)-based membrane. The methanol permeability of directional conducting membrane is very low, which is about twice smaller than that of Nafion₁₁₇. In addition, the membranes show a relatively high oxidative durability in H₂O₂ solutions, with only about 10% weight loss after the membrane being immersed in 3% H₂O₂ solution for 120 h. All the properties of prepared directional conducting membrane indicate their promising prospects in proton conducting membrane applications.     

杭州文化创意产业区的空间发展格局及空间影响

在我国城市化发展转型的大环境下,随着城市新区的开发以及城市中心区传统产业的外迁和置换,文化创意产业区建设正日益受到城市决策者和研究者的关注。本文以杭州为例,在分析目前城市文化创意产业区建设现状的基础上,探讨了其在城市宏观层面的空间发展格局与发展的基本模式。     

Comparison study on different ITM‐integrated MCFC hybrid systems with CO2 recovery using sweep gas

Previous study shows the ITM (oxygen ion transfer membrane)‐integrated MCFC (molten carbonate fuel cell) hybrid system with CO₂ recovery can maintain high efficiency; however, the oxygen partial pressure on the ITM permeate side is usually 1 atm, which requires a very high pressure ratio of the ITM air compressor in order to separate the oxygen; using the sweep gas can solve this problem. In this paper the ITM‐integrated MCFC hybrid systems with CO₂ recovery using different sweep gases are studied. With the Aspen plus software, two systems with different sweep gases are established, and their performances are compared with the benchmark system without sweep gas; the effects of key parameters on the optimum system performance are also investigated. Results show that compared with the benchmark system, the efficiencies of the systems with sweep gases are increased and the pressure ratios of the air compressors are decreased; the system using pure CO₂ as sweep gas can improve the system efficiency by 1.25%, which is superior to the system using the mixture gas of CO₂ and H₂O as sweep gas. Achievements from this paper will provide a valuable reference for CO₂ recovery from the MCFC hybrid power system with lower energy consumption. Copyright © 2016 John Wiley & Sons, Ltd.     

低弗劳德数水流辅助消能工空蚀问题研究

辅助消能工的空蚀问题是水利工程中重点关注的问题之一。本文针对水利工程中常遇到的消力墩表面空蚀破坏问题进行了试验研究,提出通过两种方法解决空蚀问题:采用消力池+不完全宽尾墩+消力墩联合消能工和圆化消力墩棱角。试验结果表明:采用联合消能工不仅能够减小底流流速、减轻水流对消力墩的冲击力,而且能够提升消力墩表面的空化数、有效提高消能率。适当圆化消力墩棱角可以降低初生空化数;还能减轻紊动、提升空化数,从而提高消力墩的抗空蚀能力。     

基于并行机制的变电站远动联调验收模式

随着广域分布式地县一体调度技术支持系统和湖州地区备用调度系统建成投运,多套系统多个通道的联调、验收工作复杂且繁重。为确保联调验收质量、提高工作效率,在工作方法和工作模式上改造传统串行方式,引入并行机制,提出一种基于并行机制的变电站远动联调验收模式。新模式在联调方法上改变逐套系统、逐个通道、逐点调试的方法,采用多位自动化主站人员同时联调多个远动通道数据。在工作流程上改变先自动化联调后监控验收的模式,将监控验收结合到自动化联调过程中一并开展,在保证联远动调验收质量的前提下大大提高了工作效率。     

220kV变电站W相电流互感器故障分析及处理

针对某220kV变电站W相电流互感器故障情况,对W相电流互感器进行油色谱试验、带电相对介质损耗及电容量测试、高压试验和解体分析,认为W相电流互感器内部存在低密度能量的局部放电缺陷是造成本次故障的主要原因,并提出了处理措施。     

电压间谐波对紧凑型荧光灯光闪变效应的实验研究

为进行实验研究,对IEC闪变仪模型中的加权滤波器进行分解,提出闪变仪的分解模型,该模型可直接导入实验获得的光通量信号以进行光闪变强度Pst计算,实验验证了该模型的可行性和有效性;设计并建立了实验装置,利用高准确度照度计采集紧凑型荧光灯在含有特定间谐波频率和幅值的电压下的光通量输出,使用闪变仪分解模型,对其在间谐波电压下的光闪变效应进行实验研究,获得了紧凑型荧光灯在不同间谐波频率和含量下的光闪变强度Pst,并据此提出了针对紧凑型荧光灯光闪变的间谐波限制曲线。     

氩霜竞争吸附实验平台的设计与验证

为了研究氩霜对氦气与氢气的混合气体竞争吸附的特性,设计并搭建了一套低温实验台,该实验台主要包括液氦恒温器、吸附室和气体缓冲室,能实现氩霜在低温下对纯氦气、纯氢气以及两种气体的混合物的吸附特性的研究。从理论上分析了液氦恒温器的热力性能,预冷恒温器低温部分所需液氦为35.3 L,系统漏热为7.109 2 W,稳定运行时液氦耗量为9.8 L/h。为了验证本实验台的可信度,以氦气为吸附质气体,研究了氩霜在液氦温度下对其吸附的吸附特性,通过与文献实验数据的对比,表明该实验台在低温下研究氩霜对不同气体的吸附研究是可信的。     

大倾角综放面预掘巷道群快速过断层技术

针对长壁工作面过断层时存在产量低、煤质差、工期长及安全系数低等问题,提出了预掘巷道群快速过断层技术,即在考虑断层落差、工作面开采条件及支架稳定性的基础上,确定出大倾角综放面过断层的"预想层位",并在此层位上预掘若干条巷道(巷道群),使工作面连续推过预掘巷道群过断层。此项技术的关键为:1)预掘巷道群围岩控制技术,包括其布置方式、预掘巷间岩柱尺寸及支护参数等;2)大倾角综放面过断层期间支架稳定性控制技术,即考虑走向角度对液压支架倾向稳定性及倾向角度对液压支架走向稳定性的影响,分析大倾角(双斜)综放面过断层期间支架失稳机理,得出支架不倾倒、不滑移所需的临界支护阻力,并提出对应控制技术。高庄煤矿3上1101大倾角综放面应用此项技术,快速(历时23 d)推过了落差为13.5 m的断层,保证了工作面(呈双斜状态)过断层期间原煤产量的稳定。