复杂可修系统任务测试性建模

为了更加合理地衡量复杂可修系统执行任务过程中的测试性,建立一种符合复杂可修系统功能特性和任务特点的物理模型和数学模型。分析了复杂可修系统任务测试性参数,选取任务故障检测率和任务故障隔离率作为度量参数,结合系统测试性功能层次结构,建立系统任务测试性物理模型,并在此基础上,建立系统串并混联的任务测试性数学模型,针对某型潜艇燃油分系统开展验证分析工作。分析结果表明：该模型贴近实际,适用于复杂可修系统任务测试性建模。     

Experience on integration of solar thermal technologies with green buildings

The green buildings of Shanghai Research Institute of Building Science include an office building for the demonstration of public building and two residential buildings, which are for the demonstration of flat and villa, respectively. Here, a solar-powered integrated energy system including heating, air-conditioning, natural ventilation and hot water supply was designed and constructed for the office building. However, only solar hot-water systems were installed for the flat and villa. All the three solar thermal systems have continuously run for 2 years. Two different integrated approaches have been put into practice in the two green residential buildings. It is shown that, for new buildings, solar collectors can be mounted on balconies and awnings besides roofs, on condition that solar systems become part of the general building design. The solar-powered integrated energy system has the advantage of high utilization ratio with different functions according to different seasons. It is testified to be capable of taking on about 70% of the yearly building load regarding the involved space under the weather condition of Shanghai.     

Pre-irradiation grafting of styrene and maleic anhydride onto PVDF membrane and subsequent sulfonation for application in vanadium redox batteries

A poly(vinylidene difluoride) (PVDF) membrane was grafted with styrene (St) and maleic anhydride (MAn) using an electron-beam-induced pre-irradiation grafting technique. The grafted membrane (PVDF-g-PS-co-PMAn) was then sulfonated and hydrolyzed to give an ion exchange membrane (denoted as PVDF-g-PSSA-co-PMAc) for vanadium redox flow batteries (VRB) use. Micro-FTIR analysis indicated that PVDF was successfully grafted and sulfonated at the above condition, and the membrane with a high grafting yield (GY) can be easily prepared in a St/MAn binary system at low dose due to a synergistic effect. The water uptake and ion exchange capacity (IEC) of the PVDF-g-PSSA-co-PMAc membrane increased with GY, so too did the conductivity. At a GY of 33.6%, the resulting PVDF-g-PSSA-co-PMAc membrane showed a much higher IEC and conductivity than a conventional Nafion117 membrane, and a much lower permeability of vanadium ions: ca. 1/11 to 1/16 of that through Nafion117. Open circuit voltage measurements showed that the VRB assembled with the PVDF-g-PSSA-co-PMAc membrane maintained values above 1.3 V after a period of 33 h, which was much longer than that with the Nafion117 membrane. It is expected that this work provides a new approach for the fabrication of ion exchange membranes for VRB.     

Design and performance of a solar-powered air-conditioning system in a green building

A solar-powered adsorption air-conditioning system was designed and installed in the green building of Shanghai Research Institute of Building Science. The system contained 150 m² solar collectors and two adsorption chillers with nominal refrigeration capacity of 8.5 kW. Based on performance characteristics of the adsorption chiller, the operation mode of the solar-powered air-conditioning system was optimized by maintaining a phase shift of 540 s between the two adsorption chillers. Thereafter, the whole system realized stable operation by the balance of heat consumption and refrigeration output. From June to August of 2005, the solar-powered air-conditioning system continuously ran between 9:00 and 17:00. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 h operation and the maximum value exceeded 20 kW. Solar fraction for the system in summer was 71.7%, which corresponded to the designed cooling load (15 kW). Compared with the ambient temperature, it was deduced that solar radiant intensity had a more distinct influence on the performance of solar-powered air-conditioning system.     

电信重组后射频同轴连接器及电缆组件的市场前景分析

3G工程的启动为我国电信业的发展带来全新的、巨大的驱动力,而电信业重组后形成的失衡的竞争格局又使3G建设成为新一轮的竞争焦点。弱势运营商为抢夺市场份额、强势运营商为进一步巩固行业龙头地位,均不断加大对3G网络的投资,因此也为国内射频同轴连接器及电缆组件生产企业带来了巨大的需求市场。     

潜基导弹动基座瞄准技术

系统分析和论述了国内外采用和正在研究的先进动基座瞄准技术,包括动基座调平、光电瞄准、传递对准、自主对准等多种对准方法在动基座中应用的原理,论述采用不同方式完成初始方位对准后平台系统变射向的方法,为进一步减小初始对准误差对导弹落点精度的影响,提出惯性/星光制导方案及在动基座潜基弹道导弹中的工作流程和工作方法。     

基于复合式抛物面聚光器的LED反光杯建模研究

针对复合式抛物面聚光器(CPC)无法在TracePro软件中直接建模的不足,结合TracePro软件特点,对CPC关键参数进行了分析,通过数学模型对参数之间的几何关系进行了推导,得出了计算公式,实现了CPC在TracePro中的建模。将CPC设计成反光杯应用于LED灯具中,可方便地进行光学模拟和分析,进而有效地缩短产品开发周期和开发成本。为CPC设计提供了数学依据,通过建模验证了该方法的可行性,有效提高了设计效率。结果表明,用通过该方法设计出的CPC做成的LED反光杯,可以极大地提高灯具的发光效率。为其在照明领域的发展应用提供了更好的使用价值和前景。     

深空、自由空间、非可视散射和水下激光光子通信

激光光子通信是国际通信前沿研究领域的一个重要的研究方向。近年来激光光子通信技术被广泛地应用于深空通信,卫星与卫星激光通信,自由空间通信,非可视散射通信和水下通信等领域内。首先,由于自由空间激光光子通信系统的高下传速率优势,使其成为未来深空通信重要的研究方向。其次,基于自由空间和非可视散射光子通信方式的分布式传感网络逐渐从实研室走向实际应用。在农业土壤质量检测、地震灾害事件、结构件压力、医疗参数数据、污染物输运和军事应用领域具有广泛的应用价值。另外,水下光子通信技术能够满足与水下观测和海底检测以及钻井平台相关的研究和检测所需要的高速率通信需求。总之,由于激光和光子探测技术的独特优势,光子通信技术研究兴趣日益强劲,将在深空、自由空间和水下通信中被广泛的应用和深入研究。     

量子级联红外探测器

半导体基中远红外探测器在成像、传感、国家安全以及国防领域具有广泛的应用背景.目前,在这个领域最主流的技术之一是量子阱红外探测器( QWIPs).传统的量子阱红外探测器往往存在较大的暗电流和较低的工作温度等限制.量子级联探测器( QCDs)是一种新型的光伏型量子阱红外探测器.其工作原理基于电子吸收光子后在量子阱的子带间跃...     

云计算数据中心服务器数量动态配置策略

云计算数据中心由通过高速网络连接的大量服务器构成,一种有效的节能措施是维持与系统负载成比例的活跃服务器数量同时切换剩余服务器到空闲模式,由此分别产生操作能耗和切换能耗。该文研究如何动态配置活跃服务器数量以最小化数据中心能耗(操作与切换能耗之和)的问题。首先,建立了问题的NP数学模型,并分析了无切换能耗情况下最优解的特性;其次,通过消除整数动态规划的递推过程,推导具有多项式复杂度的最优静态算法;最后,采用对未来负载的最坏预测结果作为约束制定了优化在线策略。仿真结果表明,所提出的静态最优和动态优化策略能够适应外界负载的剧烈变化趋势始终谨慎调整活跃服务器和休眠服务器的比例,以接近最优的能耗代价维持数据中心的平稳运行。