A high‐resolution hybrid scheme for hyperbolic conservation laws

A new hybrid scheme is proposed, which combines the improved third‐order weighted essentially non‐oscillatory (WENO) scheme presented in this paper with a fourth‐order central scheme by a novel switch. Two major steps have been gone through for the construction of a high‐performance and stable hybrid scheme. Firstly, to enhance the WENO part of the hybrid scheme, a new reference smoothness indicator has been devised, which, combined with the nonlinear weighting procedure of WENO‐Z, can drive the third‐order WENO toward the optimal linear scheme faster. Secondly, to improve the hybridization with the central scheme, a hyperbolic tangent hybridization switch and its efficient polynomial counterpart are devised, with which we are able to fix the threshold value introduced by the hybridization. The new hybrid scheme is thus formulated, and a set of benchmark problems have been tested to verify the performance enhancement. Numerical results demonstrate that the new hybrid scheme achieves excellent performance in resolving complex flow features, even compared with the fifth‐order classical WENO scheme and WENO‐Z scheme. Copyright © 2015 John Wiley & Sons, Ltd.     

HMSIW-based switchable units using super compact loaded shunt stubs and its applications on SIW/HMSIW switches

Half-mode substrate integrated waveguide (HMSIW) switchable unit, built by HMSIW section with loaded single or multi-microstrip shunt stub(s), was proposed in this work. Both shorted and opened stubs were studied, investigated and compared, bandwidth enhancement method for proposed switchable units was proposed and demonstrated. Based on these switchable units, narrowband and broadband HMSIW single-pole-single-through (SPST) switches, SIW SPST switch and SIW/HMSIW-based single-pole-double-through (SPDT) switch were designed, fabricated and measured. Good performances were observed experimentally for these proposed circuits, showing the advantages of proposed concept and an excellent candidate for switchable or reconfigurable SIW/HMSIW circuits or systems.     

Stimuli-Responsive Cycloaurated “OFF-ON” Switchable Anion Transporters

Anion transporters have shown potential application as anti-cancer agents that function by disrupting homeostasis and triggering cell death. In this research article we report switchable anion transport by gold complexes of anion transporters that are “switched on” in situ in the presence of the reducing agent GSH by decomplexation of gold. GSH is found in higher concentrations in tumors than in healthy tissue and hence this approach offers a strategy to target these systems to tumors.     

多端口通信设备测试装置的设计

基于射频开关通过互联的方式获得不同的逻辑组合,从而形成射频开关网络对网络分析仪的端口数量进行扩展,用以满足多种功能的测试需求。文章介绍的装置同时具有4端口全矩阵,4端口半矩阵的功能,且可以通过改变跳线连接来实现不同功能的测试。从而大幅度提高多端口射频器件(如多端口基站天线,多系统合路平台(POI),多频合路器等)生产测试效率、降低测试成本,也可应用于无线终端或基站的多端口射频测试。     

Synthesis,tautomeric stability,spectroscopy and computational study of a potential molecular switch of (Z)-4-(phenylamino)pent-3-en-2-one

The (Z)-4-(phenylamino) pent-3-en-2-one (PAPO) was synthesised applying carbon-based solid acid and described by experimental techniques. Calculated results reveal that its keto-amine form is more stable than its enol-imine form. A relaxed potential energy surface scan has been accomplished based on the optimised geometry of NH tautomeric form to depict the potential energy barrier related to intramolecular proton transfer. The spectroscopic results and theoretical calculations demonstrate that the intramolecular hydrogen bonding strength of PAPO is stronger than that in 4-amino-3-penten-2-one)APO(. In addition, molecular electrostatic potential, total and partial density of stats (TDOS, PDOS) and non-linear optical properties of the compound were studied using same theoretical calculations. Our calculations show that the title molecule has the potential to be used as molecular switch.     

河南油田通信网络升级改造方案设计

根据计算机网络技术发展趋势和油田计算机网络的现状,本设计采用接入层、汇聚层、核心层三个层次网络构架,更新出口路由器为防火墙、更新核心交换机、新建缓存系统、认证和网管系统等,进而实现系统整体升级。     

电爆丝断路开关输出性能分析

电爆丝断路开关是电感储能系统中广泛应用的技术。文中首先分析了电爆丝断路开关(EEOS)在电感储能系统中工作的基本原理,在理论上分析了影响电爆丝断路开关输出性能的因素。接着设计了一组试验来验证理论分析。首先在同一电路中,相同起爆时刻,比较了铜丝和银丝输出的电压脉冲。从理论上分析了银丝比铜丝输出电压幅值更高,脉冲宽度更窄的原因。接着采用相同根数的铜丝,在电流大小不同电路中进行试验,结果发现电流大的回路产生的电压幅值更高,脉宽更窄。最后采用1根银丝和4根银丝进行实验。实验结果是1根银丝产生的脉冲宽度小,幅值大;4根银丝产生的脉冲宽度大,电压幅值小。然后得出结论金属丝状态变化过程中流过金属丝的电流密度影响产生电压脉冲的宽度。     

An experimental/computational approach to identify moduli and residual stress in MEMS radio-frequency switches

In this paper, we identify the Young's modulus and residual stress state of a free-standing thin aluminum membrane, used in MEMS radio-frequency (rf) switches. We have developed a new methodology that combines a membrane deflection experiment (MDE) and three-dimensional numerical simulations. Wafer-level MDE tests were conducted with a commercially available nanoindenter. The accuracy and usefulness of the MDE is confirmed by the repeatability and uniformity of measured load-deflection curves on a number of switches with both wedge and Berkovich tips. It was found that the load-deflection behavior is a function of membrane elastic properties, initial residual stress state and corresponding membrane shape. Furthermore, it was assessed that initial membrane shape has a strong effect on load-deflection curves; hence, its accurate characterization is critical. Through an iterative process and comparison between MDE data and numerical simulations, the Young's modulus and residual stress state, consistent with measured membrane shape, were identified. One important finding from this investigation is that variations in membrane elastic properties and residual stress state affect the load-deflection curve in different regimes. Changes in residual stress state significantly affect the load-deflection slope at small values of deflection. By contrast, variations in Young's modulus result in changes in load-deflection slope at large deflections. These features are helpful to decouple both effects in the identification process.