Synthesis of TiO<Subscript>2</Subscript> Hybrid Molecular Imprinted Polymer for Ethofumesate Linked by Silane Coupling Agent

TiO₂ hybrid molecular imprinted polymer (MIP) for ethofumesate using methacrylic acid (MAA) as the functional monomer and silane coupling agent 3-(trimethoxysilyl) propylmethacrylate (KH570) as organic–inorganic connective bridge was synthesized via photo-excitation method. Hydrogen bond was proved to act between MAA and ethofumesate for pre- and post-polymerization binding properties as testified by UV spectrometric method. KH570 modified TiO₂ nanoparticles were prepared via sonochemical reaction, which can accelerate hydrolysis, increase collision chance for the reactive system and improve the dispersion of the nanoparticles. Scanning electron microscope (SEM), transmission electron microscope (TEM), binding and the adsorption kinetics experiments as well as thermogravimetric analysis (TGA) were employed for characterization. The results indicated that the hybrid MIP revealed a larger surface area and more ordered imprinting cavities with improved thermal stability compared to organic-only MIP. Furthermore, faster adsorption kinetics and enhancive adsorption capacity were achieved, which made it promising in chemical sensor applications.     

一种考虑分布电容的模糊故障测距算法

提出了一种考虑分布电容的故障测距新算法。该算法基于微分方程描述的线路数学模型，利用单端信息对高压输电线路进行故障测距，保留了解微分方程算法的简单可靠、现实可行、不必考虑衰减直流分量和谐波及电网频率波动影响的特点，同时考虑过渡电阻和分布电容的影响，克服了传统解微分方程法中在经高阻接地故障时测距误差过大和忽略分布电容引起的故障定位不准确的缺点。为了检验算法的精度，进行了大量的动模实验。结果表明，算法原理正确并具有较高的测距精度。     

Fabrication of a poly-Si thin-film transistor with storage capacitor

The fabrication process of a low-temperature poly-Si thin-film transistor (TFT) with a storage capacitor was studied. The atmospheric-pressure chemical-vapour deposited SiO₂ protected the buried indium tin oxide (ITO) from reduction by a pure H₂ plasma treatment that was essential for the effective improvement of the poly-Si TFT characteristics. Thus, a storage capacitor with an ITO (picture electrode)-SiO₂-ITO (buried common electrode) structure was successfully fabricated. The poly-Si TFT with a channel width/length W/L ratio of 5 drove a 3 pF storage capacitor in 2 μs, and it showed superior driverability for LCD use. The TFT also had good hold characteristics under illumination for the realization of grey-scale representation.     

Strengthening of Preloaded RC Beams Using Hybrid Carbon Sheets

Reinforced concrete (RC) beams subject to service loads of 40 or 60% of steel yielding were strengthened using hybrid continuous carbon fiber sheets. The hybrid systems were made of high-strength and high-modulus carbon sheets, and compared with systems using only high-strength carbon. It was found that the use of high-modulus carbon sheets in hybrid systems could increase the yielding load, the flexural stiffness, the postyielding ductility, and reduce the crack opening in concrete. The slope changes on load-deflection curves at steel yielding are not noticeable in hybrid systems. The tensile strains developed in hybrid sheets after the fracture of high-modulus carbon are higher in magnitude and distributed in a larger area, leading to an ultimate carbon fracture with concrete crushing. These unique features are attributed to the high stiffness and low ultimate tensile strain of the high-modulus carbon fibers which stiffen the structures, avoid or delay the fiber-reinforced polymer debonding, and facilitate the deformability during their subsequent breakdown.     

Stabilization of inter-area and/or oscillatory modes in large-scale power system by voltage impedance power system (VIPS) apparatus based on decentralized control scheme

New technologies such as power electronics have made it possible to change continuously the impedance of a power system not only to control power flow but also to enhance stability. A power system incorporating a variable impedance apparatus such as a variable series capacitor (VSrC) and high-speed phase shifter (HSPS) is called VIPS (Variable Impedance Power System) by the authors. This paper proposes a novel control method of VIPS apparatus such as VSrC and HSPS installed at an interconnecting point for stabilizing inter-area unstable and/or oscillatory modes. The proposed design method of the control system is a kind of hierarchical decentralized control method of a large-scale power system based on a Lyapunov function. Under the proposed control scheme, each subsystem can be stabilized independently by local controllers such as AVR, speed governor and PSS, and then the whole interconnected system can be stabilized by VIPS apparatus taking into account interactions between subsystems. The effectiveness and robustness of the VIPS apparatus control are shown by numerical examples with model systems including a large-scale power system.     

压电超声微电机混合结构定子的固有频率特性分析

压电超声微电机是依靠定子振动变换能的功率器件，定子性能将直接关系到微电机能否实现，本文采用Ｒａｙｌｅｉｇｈ－Ｒｉｔｚ方法来分析机械中经常采用的多层膜结构（混合结构）定子的固有振动特性，推导中考虑了平面应力和弯曲应力对固有频率的影响，模拟计算和实验结果符合得较好，此外还讨论了定子有关参数对固有频率的影响。     

用于高压电容器的SrTiO3基陶瓷

报道ＳｒＴｉＯ３基陶瓷的制备方法和介电性质，给出了用此种陶瓷制成的高压电容器的试验结果，并对它位进行了讨论。     

LASER ENHANCED ELECTROCHEMICAL MACHINING PROCESS

An experimental apparatus was designed and built for the hybrid process of laser enhanced electrochemical machining (ECM). Comparison experiments had been done between solely ECM and laser enhanced ECM. The machining performance of hybrid process was investigated and compared with solely ECM. The principle of the hybrid process was exposed by analyzing the microstructure of machining surface. The results show that the hybrid process has advantages in machining accuracy, surface quality, and machining efficiency.     

基于MATLAB仿真的无功补偿电容器投切控制研究

对目前常用的无功补偿电容器投切控制方案所存在的不足进行了详细的分析,给出了补偿电容器投切的优化控制方案,并在MATLAB电力仿真环境下进行了仿真试验。结果表明,所提出的优化方案达到较理想的效果。     

Hybrid LES — Review and assessment

In the late eighties and up to the beginning of nineties computation of turbulent flows is mostly dominated by RANS (Reynolds Averaged Navier-Stokes Simulation) type modelling. During the last few years URANS (Unsteady RANS) and LES (Large Eddy Simulation) type of approaches have been attempted with some success. Yet, there have been many difficulties when LES is applied to practical engineering problems and to high Reynolds number flows as energy dissipating eddies become really small and mesh resolution required for a reasonably resolved LES approaches that of DNS (Direct Numerical Simulation). An alternative solution suggested was to combine RANS and LES, which in general referred to as Hybrid LES. There have been many proposals for combining RANS and LES in different ways. In this article, some of the issues involved in performing hybrid LES reported in the recent literature is briefly reviewed.