Study of Liquid Phase Shifter for ICRF on EAST

A method of current drive with Ion Cyclotron Range of Frequency （ICRF） on Experimental Advanced Superconducting Tokomak （EAST） is described. A variety of liquid silicon oil heights in the phase shifter will bring the phase difference to the current drive. It is found that the current drive can be achieved by using the phase shifter. The liquid phase shifter is one of the impedance matching systems too.     

A uniplanar printed antenna with an inverted L‐shaped coupling feed for LTE/GSM/DCS/PCS/UMTS operations

A novel uniplanar printed antenna with a total size of 115 × 40 mm² is proposed for mobile device application. By using an inverted L‐shaped feeding mechanism and a meandered shorting strip, a dual‐band operation with wideband characteristic can be achieved. Here, the lower operating band is able to cover the LTE 700 and GSM 850/900 operations, while the higher operating band allows DCS 1800, PCS 1900, UMTS, and LTE 2300 operations. Furthermore, in order to increase the bandwidth of the higher operating band so that LTE 2500 operation can also be covered, an additional parasitic stub is attached to the feed line to excite a resonant frequency at around 2.72 GHz. Parametric studies via simulation are carried out, and prototype of the proposed antenna is also experimentally investigated to validate the simulated results. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

基于动态依赖的类间测试顺序研究

类间集成测试顺序决定着测试成本的大小,为了得到合适的测试顺序,提出了一种基于动态依赖的类间测试顺序的方法。首先分析对象关系图中类间依赖关系,然后运用边删除规则去除环路,最后运用有向无环图的拓扑序列给出类的测试顺序。仿真结果表明,本文的方法较Briand的方法减少了42%的测试桩。此方法满足最小化测试桩的需要,提高了测试效率,减少了测试成本。     

H型钢部分包裹混凝土组合短柱偏心受力性能研究

对6根焊接普通H型钢部分包裹混凝土组合短柱进行了偏心受压试验的研究,主要考虑含钢率、翼缘宽厚比等因素.试验结果表明,钢与混凝土能够很好地协同工作,达到最大荷载前,翼缘没有发生局部屈曲.这种组合结构柱最终的破坏模式为混凝土压碎,横向系杆间翼缘发生局部屈曲.     

基于平行耦合线和开路枝节的小型带通滤波器设计

为了解决耦合线滤波器谐波抑制问题,提出了一种新的结构简单的平行耦合线带通滤波器.该滤波器由平行耦合线和开路枝节组成.首先基于耦合线带通滤波器的等效电路图,通过奇偶模理论得到设计方程,并设计了带通滤波器;分析了滤波器特性与电参数之间的关系;通过仿真优化得到了滤波器的物理尺寸;制备并测试了滤波器的S参数,仿真结果和测试结果基本一致.该滤波器具有结构简单、面积小等优点,并通过引入传输零点实现了较宽的阻带抑制和较好的选择性.     

Independently controllable dual‐band microstrip bandpass filter using quadruple‐mode stub‐loaded resonator

In this article, a quadruple‐mode stub‐loaded resonator (QM‐SLR) is introduced and its four modes are excited using a simple approach, which can provide a dual‐band behavior. By changing the length of the loaded stubs, independently tunable transmission characteristics of the proposed quadruple‐mode stub‐loaded resonator were extensively described for filter design. Moreover, microwave varactors were adopted to represent the length variation of the loaded stubs for the dual‐band tunability. The equivalent circuit modeling of the open stub with microwave varactor was given and discussed. Then, adopting the compact quadruple‐mode stub‐loaded resonator with three varactors, an independently controllable dual‐band bandpass filter (BPF) was designed, analyzed, and fabricated. Its separated bandwidths and transmission zeros can be tuned independently by changing the applying voltage of the microwave varactors. A good agreement between simulated and measured results verified the design methodology. The proposed filter possesses compact size, simple structure, and excellent dual‐band performances. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:602–608, 2016.     

具有耐火钢短梁的钢框架梁-柱连接抗火性能模拟

通过有限元模拟探讨将耐火钢短梁应用于钢框架梁 柱连接以提高连接抗火性能的可能性.考察三维有限元建模过程中模型简化、网格划分、求解方法和接触关系等关键技术,以提高计算效率并确保分析结果的可靠性.提出3个确定极限温度的准则并应用于钢框架,通过比较可知：对于采用普通钢的钢框架,采用准则1与准则2确定的极限温度与由最大挠度为L/20和L/10所确定的临界温度较接近,这有益于指导钢框架抗火设计.比较普通钢与耐火钢短梁的变形可知：耐火钢的使用可以有效控制跨中挠度变形,使最大变形值减小1/2以上.     

A novel compact planar ultra‐wideband antenna with dual band‐notched characteristics

A novel planar ultrawideband monopole antenna with dual notched bands is presented. The antenna mainly consists of a radiation patch and a modified ground plane. To realize dual band‐notched characteristics, a U‐shaped stub embedded in the rectangular slot of the radiation patch and a novel coupled open‐/shorted‐circuit stub resonator are used on the backside of the substrate. The bandwidth of the dual notched bands can be controllable by adjusting some key parameters. The simulated and measured results indicate that the proposed antenna offers a very wide bandwidth from 2.6 to 18 GHz with Voltage Standing Wave Ratio (VSWR) < 2, except the dual notched bands of 3.3–3.7 GHz (World Interoperability for Microwave Access [WiMAX]) and 5.15–5.825 GHz (Wireless Local Area Network [WLAN]). Furthermore, good group delay and stable gains can be achieved over the operating frequencies. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:48–55, 2015.     

Java RMI设计实现的分析与研究

随着Java开发技术的迅猛发展,其具有的跨平台、代码可移植性、安全高效等功能逐渐被认可,一种基于Java的远程方法调用(RMI)为进行Java开发应用提供了行之有效的解决方案。详细介绍了设计RMI的具体步骤,并给出了具体实现的关键代码。     

实时操作系统的性能分析和评估

针对实时操作系统的基本原理和运行机制,提出评估系统实时性能的基本参考指标,并分析各项指标对系统实时性能的影响。采用软件插桩的方法测试不同实时操作系统的性能指标,根据测试结果对系统实时性能进行综合对比评估。