Application of asymptotic waveform evaluation to eigenmode expansion method for analysis of simultaneous switching noise in printed circuit boards (PCBs)

In this paper, the asymptotic waveform evaluation (AWE) technique is first applied to the conventional eigenmode expansion method for characterizing a power/ground (P/G) plane pair and analyzing the simultaneous switching noise on such plane pairs for printed circuit boards or multichip modules. The application of AWE avoids a large number of iterations in computing the impedance frequency response of a P/G plane pair structure and greatly reduces the computation time. Meanwhile, to obtain an accurate solution in an entire frequency range, we employ the complex frequency hopping technique which can help select multiple expansion points. In addition, the proposed approach can also be used to characterize the P/G plane pair structures with irregular shapes. Three examples demonstrate its high efficiency and good accuracy.     

加强无线电管理,日常监督检查势在必行

随着社会经济的迅速发展,无线电通信事业取得了很大进步,无线电通信广泛应用于各行各业,在经济发展、社会进步中发挥了重要的作用.但目前一些单位和个人无视国家有关频率管理和无线电设备管理的有关法规,擅自占用频率和非法设台情况比较严重,极大地损害了电磁环境和秩序,干扰了航空导航、公安、消防、护林防火、“三防”等重要通信业务,对无线电通信的可持续性发展造成了极大隐患,加强无线电管理日常监督检查势在必行.     

低强度激光血管内照射对海洛因戒断综合征的疗效观察

对于毒瘾戒断综合症的治疗一般采用强行戒断或逐步撤药等方法 ,但患者非常痛苦 ,且复吸率较高。为了观察低强度He -Ne激光对戒断症状的抑制作用 ,本文用低强度激光血管内照射疗法对 3 0例吸毒戒断综合征患者进行了治疗 ,并与对照组比较。结果证明 :实验组疗效明显优于对照组 (P <0 .0 1) ,为进一步的临床应用提供了临床依据。     

电子电气设备的熔断器、断路器保护

熔断器、断路器是电子电气设备最常用的保护电器,熔断器可以实现过载、短路保护,断路器除具上述功能外,还能实行失压保护.根据线路特点和所保护的设备,采取相应的保护设施,确保用电安全.     

A 5 mW and 5% efficiency 210 GHz InP-based heterostructure barrier varactor quintupler

This letter reviews the design, construction, and measurement of a 210 GHz heterostructure barrier varactor frequency quintupler. The quintupler utilizes planar heterostructure barrier varactors (HBVs) based on the InGaAs/InAlAs/AlAs material system and has produced a measured output power of 5.2 mW with 5.2% conversion efficiency at 210 GHz. This performance is comparable to the state-of-the-art results reported in the literature for HBV frequency triplers operating at millimeter and submillimeter wavelengths.     

A Sufficient Condition for Interolation by Functions in A~P(φ) (1

肖杰  赵大蕻 《数学季刊》1992,(4)

YAG：Nd激光照射犬气管粘膜的实验研究

An experimental study for the pathologic changes of the canine tracheal mucosa under YAG:Nd laser ablation was performed in order to master the appropriate parameters for the clinical treatment of YAG:Nd laser. 6 male and female Mongolia dogs weighing 13-18 kg were received 20W YAG:Nd laser treatment and their pathologic changes were examined instantly and 3, 7, 14 and 28 days after ablation.     

数字电视及其标准

电视技术的数字化是电视领域发展的必然趋势，它给电视技术带来了质的飞跃。在对比分析了电视模拟技术与电视数字技术的区别的基础上，对数字电视的相关技术及其标准进行了介绍，并提出了作者的看法与见解。     

Modeling, analysis, and implementation of parallel multi-inverter systems with instantaneous average-current-sharing scheme

Parallel multi-inverter systems can be designed to have the advantages of expandable output power, improved reliability, and easy N+X redundancy operation. However, a current-sharing control scheme has to be employed to enable the inverters to share the load current equally. A multi-inverter system with instantaneous average-current-sharing scheme is presented in this paper. By introducing a disturbance source to represent all the sources that may cause current unbalances, a model of the system can be built. Some key issues are discussed based on the model, including stability of the current-sharing controller, impedance characteristics and voltage regulation. Three experimental 110 VAC/1.1 kVA inverters are built and paralleled to verify the theoretical predictions.     

数字通信系统设计中FPGA的仿真

在大规模的FPGA设计中，由于逻辑过于复杂，给仿真与调试工作带来很大难度。本文结合“实用化综合接入系统”边缘路由器子系统的设计，结合仿真软件提供的接口，提出用测试程序自动生成测试向量，自动完成仿真结果检查的方法，大大降低了仿真与调试的工作量。