Ad hoc网络应用及在后3G中面临的挑战

Ad hoc网络是一种具有有限生存期的无基础设施网络。它具有动态网络拓扑、多跳通信、分布式结构、有限带宽和功率、抗毁坏、入侵性差等特点。文章围绕Ad hoc网络,从Ad hoc的发起开始,简要介绍了Ad hoc的应用方向,然后结合后3G(B3G),着重介绍了Ad hoc在B3G中所面临的挑战。     

Isoscaling in Statistical Sequential Decay Model

A sequential decay model is used to study isoscaling, i.e. the factorization of the isotope ratios from sources of different isospins and sizes over a broad range of excitation energies, into fugacity terms of proton and neutron number, R21（N, Z） = Y2（ N, Z）/Y1（ N, Z） = Cexp（αN -βZ）. It is found that the isoscaling parameters α and β have a strong dependence on the isospin difference of equilibrated source and excitation energy, no significant influence of the source size on α andβ has been observed. It is found that α and β decrease with the excitation energy and are linear functions of 1/T and △（Z/A）2 or△（N/A）2 of the sources. Symmetry energy coefticient Gsym is constrained from the relationship of a and source △（Z/A）2, /3 and source △（N/A）2.     

Electrochemical Deposition and Properties of ZnTe Nanowire Array

Pulsed electrodeposited technique is applied to fabricate ZnTe nanowire arrays with different diameters into the anodic alumina membrane in citric acid solution. The x-ray powder diffraction, scanning electron microscopy and transmission electron microscopy indicate that the high ordered, uniform and single-crystalline nanowires have been fabricated. The optical absorption spectra of the nanowire array show that the optical absorption band edge of the ZnTe nanowire array exhibit a blue shift compared with that of bulk ZnTe, and the nonlinear current-voltage characteristic is observed.     

Flat Supercontinuum Generation at 1550 nm in a Dispersion-Flattened Microstructure Fibre Using Picosecond Pulse

The generation of a flat supercontinuum of over 80nm in the 1550nm region by injecting 1.6ps 10 GHz repetition rate optical pulses into an 80-m-long dispersion-flattened microstructure fibre is demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 （ps·nm^-1·km^-1） between 1500 and 1650nm. The generated supercontinuum ranging from 1513 to 1591 nm has the flatness of ±1.5 dB and it is not so flat in the range of several nanometres around the pump wavelength 1552nm. Numerical simulation is also used to study the effect of optical loss, fibre parameters and pumping conditions on supercontinuum generation in the dispersion-flattened microstructure fibre, and can be used for further optimization to generate flat broad spectra.     

断言技术在SOC验证中的应用

主要阐述了基于断言技术新硬件验证平台用于实时监测设计描述是否违反了设计目标,提出了OVA的特点及应用,并以LCD controller的sharp接口时序为实例讲解了该方法的优点。     

认知无移盆认知无线电体系结构:无线电XML工程基础

认知无线电(Cognitive Radio)是软件无线电技术发展的下一步，是一种新的智能无线通信技术，它将智能计算能力综合到软件无线电中，从而服务于嵌入式智能代理，使其更好地适应射频环境和用户需求。利用这项技术，用户可以更充分有效地利用无线频谱和各项业务。例如，用户试图在载波负载量大的区域发送10MB的电子邮件时，认知无线电就会发出告警，并建议用户到办公室通过局域网发送。认知无线电技术是一项很有发展前景的技术，能够提高无线适应性，对无线通信技术的发展具有革命性的影响。全球无线通信巨头和科研实验室都已经致力于这一新…     

仪表放大器工作原理及其新型应用

本文介绍了仪表放大器的原理及其新型应用。     

256kDRAM的可靠性

MOS动态RAM的集成密度、性能正以每年约2倍的速度向前推进,现在是以256k位动态RAM(以下256kDRAM)为主流(图1)。由于历史的原因在多种多样的IC中,使用的工艺技术、集成密度、性能、产量等方面,通常是MOS动态RAM居首位,所以在评价IC制造技术水平方面它具有代表性。在这里,就256kDRAM的可靠性作一概述。     

激光眼损伤效应研究进展

对不同波长、不同发射方式激光眼损伤效应及其作用机理的研究,为制订及修订激光安全标准提供了必不可少的生物学依据。国外现行的安全标准,主要依据激光眼损伤阈值加以安全系数而订出辐照限值(EL)或称最大容许辐照量(MPE)。所谓损伤阈值系指有50％几率发生检眼镜或角膜裂隙灯显微镜最小可见损伤所需照射剂量,一般以角膜     

人体足跖骨的力学分析及其临床应用

本文研制新型的人体足底负荷测定装置,确定正常步态下的正常足和病理足的负荷谱.在此基础上,进行了人体足跖骨力学模型的理论分析计算和跖骨应力的实验测定,综合分析结果在足外科和矫、整形外科临床中得到了实际应用.