负性VA-LCD视角特性研究

液晶材料具有双折射效应,因此偏振光在液晶材料中各个方向上发生双折射的程度不同,这决定了LCD的视角特性和对比度随视角的变化有所不同。用光栅光谱仪测量在不同电压驱动下负性VA-LCD的电光特性,以及测量其电光特性随视角的变化;并对其三基色的电光特性和视角特性进行分析。结果表明,三基色的透过率在驱动电压2.2 V之前很小;在2.2 V后,透过率随电压的升高而增大;其中红基色和绿基色的透过率是一直升高,在电压达到5.0 V后,就是趋于平缓,而蓝基色的透过率是在3.7 V左右达到最大,而后慢慢变小,最后在电压达到6.0 V后,趋近一个稳定值。负性VA-LCD三基色的视角特性:红基色的视角范围最宽,绿基色次之,蓝基色的视角范围最窄。     

Modeling of a membrane reactor system for crude palm oil transesterification. Part II: Transport phenomena

The mechanistic modeling of biodiesel production process in membrane reactor with the consideration of chemical reaction, phase equilibrium, and ultrafiltration is important for the membrane reactor design. In part II of this work, the chemical and phase equilibrium (CPE) model for crude palm oil transesterification reaction in the membrane reactor developed in part I is extended to an integration of CPE with modified Maxwell–Stefan model, which considers multicomponent mass transport phenomena of concentration polarization and intramembrane. A good fit of simulated permeate fluxes and apparent solute rejection to the experimental data shows that the model has a good prediction capability. Reversible fouling was found to be the major fouling and no pore plugging was observed. Simulation results verified that micelles were retained by the membrane at CPO:MEOH molar ratio of 1:24 and catalyst concentration of 0.5 wt %. However, phase inversion happened when catalyst concentration of 0.05 and 0.1 wt % were used. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1981–1996, 2015     

基于FPGA的遥感相机多模式数传转接电路设计

为满足遥感相机视频处理电路的测试需求,研究并设计了一种遥感相机数传转接电路,对视频处理电路处理过的不同模式的图像数据进行格式转换,再通过Cameralink接口与上位机进行图像数据传输并实时成像,同时系统采用乒乓操作提高图像数据的传输速率。主要描述系统的主要组成和FPGA模块化设计的实现方法。以Xilinx公司XC2V型号FPGA为核心,采用VHDL语言实现图像数传转换的逻辑设计,利用RS232接口接收上位机指令实现不同模式图像信号的选择输出,对不同模式的图像信号进行格式转换。实际应用表明,本系统成像结果准确,具有较好的灵活性,能够满足多种遥感相机视频处理电路的测试需求。     

直接空冷机组电动给水泵自动并泵逻辑设计

针对直接空冷机组电动给水泵配置的特点,分析了目前国内流行的2种给水泵自动并泵逻辑设计方案的优缺点。在分析结果的基础上,引入多模式切换控制思想,对通用方案进行了改进和优化,提出了多台给水泵自动并泵的逻辑设计方案,并在多台机组控制逻辑设计中得到了应用,可为同类型机组进行给水泵自动并泵逻辑设计提供借鉴。     

Improving properties of ceramic silicone rubber composites using high vinyl silicone oil

Reactive high vinyl silicone oil (HVSO) was selected to prepare the ceramic silicone rubber composites. The effects of HVSO on the mechanical properties and thermal stabilities of ceramic silicone rubber composites were investigated. The structures of the cross‐linked network of silicone rubber with or without HVSO were studied. The intermolecular space of silicone rubber was enlarged, and the cross‐linked point was concentrated by addition of HVSO, which was demonstrated by cross‐linking densities, scanning electron microscope (SEM) images, and dynamic mechanical analysis (DMA). The cross‐linked network model was formed with the slipping of the cross‐linked points along with the silicone rubber chain. Mechanical properties of composites were enhanced by the formation of this cross‐linked network. The tear strength, tensile strength, and elongation at break of the composites were increased by 18.5%, 13.2%, and 37.4% by the adding of 2 phr HVSO, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41864.     

Co‐electrospun nanofibers of PVA‐SbQ and Zein for wound healing

In this study, electrospun biocompatible nanofibers with random orientation were prepared by physically blending poly(vinyl alcohol)‐stilbazol quaternized (PVA‐SbQ) with zein in acetic acid solution for wound healing. PVA‐SbQ was used as the foundation polymer as well as crosslinking agent, blended with zein to achieve desirable properties such as improved tensile strength, surface wettability, and in vitro degradable properties. Moreover, vaccarin drug was incorporated in situ into electrospun nanofibrous membranes for cell viability and cell attachment. The addition of vaccarin showed great effects on the morphology of nanofiber and enhanced cell viability and proliferation in comparison with composite nanofibers without drug. The presence of PVA‐SbQ, zein, and vaccarin drug in the nanofibrous membranes exhibited good compatibility, hydrophilicity, and biocompatibility and created a moist environment to have potential application for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42565.     

发电企业500kV贸易结算关口无功功率高的问题分析

针对一起发电企业在升压变电站安装无功补偿电抗器而产生大量无功调整电价的问题,对发电企业的发、用电量结算方式进行分析,提出在高压备用变压器位置设置计量点、在高压电抗器前端增设计量点等解决措施,为发供电企业在选择贸易结算计量点时提供参考。     

电能量采集与监控系统的设计与应用

针对电力系统在购电、供电和售电方面数据交互困难、计量管理不统一、条块分割等问题,提出一种"购、供、售"一体化电能量采集与监控系统,分析该系统的组成、关键技术和功能,并说明系统应用情况及应用效果。     

Preparation of Spherical AlN Granules Directly by Carbothermal Reduction–Nitridation Method

In this work, an efficient carbothermal reduction–nitridation strategy was rationally designed and delicately tailored to directly synthesize spherical granules of aluminum nitride. Effects of processing parameters, such as N₂ pressure, additives and temperature on the nitridation ratio, especially on the morphologies of the AlN granules were elaborately investigated. The experimental results showed that the elevated N₂ pressure of 0.9 MPa and additives of CaF₂ and Y₂O₃ greatly favored for forming micrometer‐sized AlN granules with smooth spherical appearance. More significantly, the underlying formation mechanism of spherical morphology and large particle size was also attentively put forward.