基于B/S结构的高职院校科研管理系统分析与设计

为了实现科研管理的信息化,结合高职院校的实际情况,提出一种基于B/S结构的科研管理系统方案,系统利用Spring MVC框架,采用三层架构的方式,开发出适用于高职院校实际情况的的科研管理信息系统,提高了科研信息管理人员的工作效率,实现了资源高度共享。     

基于发布/订阅的需求响应安全通信机制设计

随着网络攻击的日益增多,需求响应通信安全是一个值得研究的课题。文中基于发布/订阅模式实现了通信的灵活性和动态性,基于OpenID的动态密码技术进行身份认证,通过认证后进行基于角色的访问控制,信息经加密后进行通信。最后通过案例验证和安全分析表明,在计算开销增加有限的情况下,该机制能有效增强需求响应通信的安全性。     

Monolithic integration of an AlGaN/GaN metalinsulator field-effect transistor with an ultra-low voltage-drop diode for self-protection

In this paper,we present a monolithic integration of a self-protected AlGaN/GaN metal-insulator field-effect transistor(MISFET).An integrated field-controlled diode on the drain side of the AlGaN/GaN MISFET features a selfprotected function for a reverse bias.This diode takes advantage of the recessed-barrier enhancement-mode technique to realize an ultra-low voltage drop and a low turn-ON voltage.In the smart monolithic integration,this integrated diode can block a reverse bias(> 70 V/μm) and suppress the leakage current(< 5 × 10-11 A/mm).Compared with conventional monolithic integration,the numerical results show that the MISFET integrated with a field-controlled diode leads to a good performance for smart power integration.And the power loss is lower than 50% in conduction without forward current degeneration.     

Efficient synthesis of the C/D rings of atisine-type C20-diterpenoid alkaloids

A bicyclo[2.2.2]octane C/D ring system,with a lactonic ring at C-8 and C-9,of the atisine-type C₂₀-diterpenoid alkaloids,was successfully synthesized,using an oxidative dearomatization/intramolecular Diels-Alder reaction.     

In situ IR study of dimethyl oxalate hydrogenation to ethylene glycol over Cu/SiO2 catalyst

The mechanism of dimethyl oxalate hydrogenation to ethylene glycol over Cu/SiO2 catalyst was investigated by in situ Fourier transform infrared(FTIR)spectroscopy.It was found that dimethyl oxalate and methyl glycolate proceeded via dissociative adsorption on Cu/SiO2 catalyst,and four main intermediates,CH3OC(O)(O)C-M(1655 cm-1),M-C(O)(O)C-M(1618 cm-1),HOCH2(O)C-M(1682 cm-1)and CH3O-M(2924-2926 cm-1),were identified during the reaction.It was concluded that dimethyl oxalate hydrogenation to ethylene glycol mainly proceeded along the route:dimethyl oxalate →CH3OC(O)(O)C-M→ methyl glycolate →HOCH2(O)C-M→ ethylene glycol.Finally a schematic reaction network was proposed.     

高温超导带材的故障电流冲击模型

提出了一种高温超导带材的故障电流冲击模型的建立方法,该方法以超导带材的数学模型为基础,用可变电阻模拟带材的阻值变化情况;搭建了带材的电路模型,编写了电阻值的计算程序,将PSCAD/EMTDC和MATLAB通过接口程序连接到一起进行联合仿真;得到了大电流下,高温超导带材失超过程中的电流、电压及温度的波形图,并对其进行了分析。对超导带材进行了交流测量实验,并将实验得到的波形和仿真波形进行了对比和分析。     

有源EMI滤波器

Vicor Corporation近日慕尼黑上海电子展上向市场推出面向DC—DC变换器的PicorQuietPower QPI-21高密度有源EMI滤波器。该OPI-21支持48VDC．DC变换器在通信和电信的应用设计，电流高达14A，效率在99．5％上，将滤波器性能推向新的水平。