基于RFC3576协议的E3RAS主动控制系统研究

简要介绍了RADIUS协议的基本概念,介绍了RFC3576协议的基本原理,阐述了如何基于RADIUS协议实现一套基于web的BRAS上网会话的主动控制系统。     

Modeling and design of polymer-based tunneling accelerometers by ANSYS/MATLAB

A prototype design of an inexpensive polymer-based tunneling accelerometer is described in this paper. Instead of silicon, polymethyl methacrylate (PMMA) is used as the mechanical material. By using silicon molds fabricated by conventional lithography and wet-etching techniques in hot embossing, PMMA structures can be replicated within 20 min. The performance of the tunneling sensor can be estimated and improved based on mechanical-level analysis by ANSYS and system-level analysis by MATLAB. The nonlinear tunneling mechanism and electrostatic actuation are linearized using small-signal approximation. To enhance the stability and broaden the bandwidth of the tunneling accelerometer system, a feedback control system with one zero and two poles is designed. The dynamic range of the system is greatly enhanced. The bandwidth of the closed-loop system is approximately 15 kHz.     

S1240J型机市话带故障的处理

介绍制作S1240交换机市话计费带时容易出现的几种故障,并给出了相应的处理方法。     

Design of 25 Gbit/s half-rate CDR with 1:2 demultiplexer for 100 GbE optical interconnects

A 25 Gbit/s clock and data recovery(CDR) circuit with 1:2 demultiplexer for 100 Gbit/s Ethernet(100 Gb E) optical interconnects has been designed and fabricated in Taiwan Semiconductor Manufacture Company(TSMC) 65 nm complementary metal-oxide-semiconductor(CMOS) technology. A novel quadrature voltage-controlled-oscillator(QVCO) structure adopts two pairs of transconductance cell and inverters to acquire rail-to-rail output swing. A half-rate bang-bang phase detector adopts four flip-flops array to sample the 25 Gbit/s input data and align the data phase, so the 25 Gbit/s data are retimed and demultiplexed into two paths 12.5 Gbit/s output data. Experimental results show that the recovered clock exhibits a peak-to-peak jitter of 7.39 ps and the recovered data presents a peak-to-peak jitter of 7.56 ps, in response to 312-1 pseudorandom bit sequence(PRBS) input. For 1.2 V voltage supply, the CDR circuit consumes 92 m W(excluding output buffers).     

On-line Optimal Pre-decision Making for Stability Control

1.IntroductionCompetitiveusesofpowersystemshavebecomemoreandmoreimportantconcernforopenaccessofmodernpowersystems,therefore,dynamicaspectsofon-1inesecurityanalysesandcontrolsarebadlyneeded(DyLiacco,l979;CIGREWG,l997;Kunduf,l994;Riverinetal-,l994;Otaetal-,l996).Themaintasksofon-linetransientstabilityassessment(TSA)arequantitativeevaluationofthedynamicsecuritylevelbasedonactualoperatinginformation,estimationofvariousstabilitylimits,decision-makingsupportforpreventivecontrol,andpreparationo…     

分形理论在煤储层物性研究中的应用

基于分形理论在地质问题研究中的标度不变性 ,利用煤层的自然粒级组成和压汞法测出的煤中不同孔径段的比孔密资料。进行了煤岩破碎结构的块度分形和孔隙结构分形 ,并就分形特征在构造煤破碎程度的划分中的意义及其对煤层气开发的影响进行了探讨。尤其指出了煤层孔隙结构分形存在两个“无标度区” ,孔径大于 10 -10 m的分数维 (D1) ,可用于评价煤层气的解吸和运移 ,小于 10 -10 m的分数维 (D2 )可用于评价煤层气的吸附与扩散。     

峰峰矿务局宾馆空调设计系统选择与节能

结合工程实例介绍了宾馆空调系统与冷负荷的计算、设备选择及运行中的节能。     

叠层压敏电阻器的近期研制动向

从构成叠层压敏电阻器的生片材料（材料晶粒大小、生片厚度）、内电极材料、叠层结构和表面处理等方面，介绍叠层压敏电阻器的近期研制动向。     

一种低信噪比条件下点目标检测方法

本文提出了一种低信噪比条件下从图像序列中检测点目标运动轨迹的新方法。基于目标运动轨迹的连续性，构造了一种准连续性滤波器结构，采用正向－反向二次滤波算法，有效地抑制了噪声的影响。在此基础上，依据待检目标运动轨迹的性质定义了一种目标函数，将轨迹检测问题转化成为寻找该目标函数最小值的问题。进而由Ａ算法在加权图中搜索最短路径以获取目标函数的最小值，从而确定点目标的运动轨迹。实验结果表明，该方法克服了以往算     

Molecular reconstruction of naphtha by maximum information entropy method

Naphtha is the feedstock for steam cracking and catalytic reforming of aromatics. Based on the molecular library and 42 groups of practical data including the properties of density, potential aromatic content, the weight fractions of PNA and carbon number distribution, a molecular reconstruction model for naphtha was established by maximum information entropy method. The content of 451 components for naphtha were estimated. The molecular composition generated by the simulation is in good agreement with the practical data. The model can provide the referential value for the steam cracking and catalytic reforming of aromatics processes at molecular level.