基于电力线通信技术的宽带网络的运营模式和投资回报分析

我国最大的有线网络是输电和配电网络，如果能利用四通八达、遍布城乡、直达千家万户的220V低压电力线传输高速数据，无疑是解决“最后300米／100米”最具竞争力的方案。同时也无疑会对有效打破驻地网的局部垄断，为多家运营商带来平等竞争的机会提供有力的技术武器。     

机顶盒CA的实现模式及摩托罗拉机顶盒解决方案

6清开灵注射液是安宫牛黄丸的改良剂型,主要成分为牛黄,水牛角,珍珠母,黄芩,橘核,金银花,板蓝根等。具有清热解毒,化痰通络,开窍醒神功效。临     

3G一场全新规则的全新竞赛

在过去30年里，电信业巳经历了从数字到包到光以至无线的彻底技术转变，而保持不变的是以话音为中心的业务模式。     

CATV镇－村光缆网建设应注意可持续发展

本通过对县级市有线电视网络发展历程的回顾，指出在镇-村二级光缆网络建设中应注重技术标准与设备选型，以确保网络可持续发展。通过对1．31μm与1．55μm光传输系统的比较，提出建议与对策，对于有线电视村村通工程建设具有一定的借鉴意义。     

CDMA系统硬切换的解决方案

文章第一部分，简要介绍了CDMA系统中硬切换种类的几种主要形式。指出当前随着多载频基站的广泛应用．在一个相当长的时期内，我国的CDMA网络会形成多载频和单载频其存的状态．不同载频之间的硬切换将会随之增加，这就要求有一种切实可行的硬切换的解决方案。为此，文章中给出了一种经济有效的解决方案——采用Flash Beacon设备.     

Fuzzy Entropy： Axiomatic Definition and Neural Networks Model

The measure of uncertainty is adopted as a measure of information. The measures of fuzziness are known as fuzzy information measures. The measure of a quantity of fuzzy information gained from a fuzzy set or fuzzy system is known as fuzzy entropy. Fuzzy entropy has been focused and studied by many researchers in various fields. In this paper, firstly, the axiomatic definition of fuzzy entropy is discussed. Then, neural networks model of fuzzy entropy is proposed, based on the computing capability of neural networks. In the end, two examples are discussed to show the efficiency of the model.     

雅马哈新款7．1AV功放RX—V2700／1700

雅马哈两款7．1声道功放新品面向高级市场，部带有Yamaha全新升级的“电影院技术（Cinema DSP）”．DSP处理能力提高了15％，通过分析房间的反射音营造出逼真的临场感，总共拥有CLASSICAL、LIVE CLUB等23种环绕声模式。DSP-AX2700采用模拟电路与数字电路彻底分离、输入信号到扬声器输出间电路最短化的双层结构设计，24bit／192kHz高精度DAC具备对DTS、DTS ES Matrix 6．1、Dolby Digital、Dolby Digital EX、Pro Logic、DTS NeO：6 Cinema、SRS Circle Surround II Cinema等18种环绕音频格式的硬件解码能力。     

Decomposition of the Two Lowest Lamb modes in a Bonded Plate

Based on the expression of the dispersion equation of Lame waves in an adhesive two-layered plate pressented in our proevious paper [Chin,Phys,Lett,18(2001)1483],the two lowest Lamb modes,the symmetric mode S0 and the antisymmetric mode A0 are successfully decomposed in the low-frequency regime,Relations between the rigidity of the bond and the velocity of the two Lamb modes are found,which lay a foundation for the estimation of the bond rigidity of the adhesive plate.The influence of the variations of the bond rigidity in terms of the stiffness constants KN and KT of the spring model on the velocity of the two Lamb modes in discussed and numerically evaluated.numerical results indicate that the deterioration of the bond rigidity causes the phase velocity decrease for Lamb modes of the two lowest order,thus having a possibility for the evaluation of the bonding state of the adhesive plate by using ultrasonic wave velocity measurement.     

ARCAM FMJ AV9/P7前后级多声道功放

ARCAM进入AV领域之后，所有的AV类产品均保持着与Hi-Fi产品相同的声音水准。2002年时他们推出了FMJ AV8环绕声前级处理器，配合FMJ P7七声道功放，构成Hi-End级的多声道功放系统。经过4年的潜心研究，最近ARCAM又推出了更前卫的FMJ AV9前级处理器，除了能应对当前各种各样的环绕声模式之外，