虚拟现实技术的国内外研究现状与发展

虚拟现实技术是一项新兴技术,结合了多种技术如多媒体技术、计算及图形技术、网络技术、人机交互技术、仿真技术以及立体显示技术等等,前景非常的广阔。文章结合了虚拟现实技术国内外的研究现状对虚拟现实技术的发展趋势进行了分析。     

国内外半导体设备技术与市场

概述了国内外半导体设备技术动态,介绍了光刻技术、CMP技术、膜生长技术、刻蚀技术、离子注入技术、清洗技术及封装技术的发展现状和技术趋势,预测了全球半导体制造设备未来市场变化,并提出了国产半导体设备技术创新的途径。     

液滴分析技术

介绍了用于液滴分析的光纤液滴分析技术、电容液滴分析技术、图像液滴分析技术、光谱液滴分析技术的原理、数学模型等.对这些技术进行了分析比较,提出了各种技术存在的问题,展望了液滴分析技术的发展前景.     

光实时延时技术进展

分析了光实时延时技术(OTTD)出现的背景,讨论了OTTD技术的理论基础,在此基础上,分别讨论了基于光纤的OTTD技术、基于光纤光栅的0TTD技术和基于光波导技术的OTTD技术.针对各种类型的技术讨论了其主要技术特色和优缺点.     

SiGe异质结晶体管技术的发展

以全球信息产业需求及技术发展为背景,回顾了以能带工程为基础的、在现代通信领域得到广泛应用的SiGe异质结晶体管技术的发展历程。介绍了分子束外延、超高真空化学气象淀积和常压化学气象淀积3种典型的SiGe外延技术并对比了这三种技术的优缺点。在此基础上,对SiGe HBT技术进行了分析总结并列举了其典型技术应用。以IBM的SiGe BiCMOS技术为例,介绍了目前主流的SiGe异质结晶体管技术-SiGe BiCMOS技术的研究现状及典型技术产品。最后对正在发展中的SiGe FET技术做了简要介绍。在回顾了SiGe异质结晶体管技术发展的同时,认为未来SiGe异质结晶体管技术的提高将主要依赖于超薄SiGe基区外延技术。     

室内空气污染危害及其净化技术的探究

概述了室内空气污染物的来源、种类及其对人体健康的危害,介绍了目前室内空气净化技术有吸附净化技术、光催化技术、离子化法净化技术、臭氧法净化技术、组合净化技术,并且分析了各技术的优缺点。提出了组合净化技术已经成为今后该领域研究的一个重要方向。     

无线城域网（WMAN）下两种接入技术的分析比较

当前,WiMAX技术和McWiLL技术已经成为无线城域网下接入技术研究的热点。首先简要介绍了WiMAX技术和McWiLL技术的发展及现状,分别分析了两类接入技术的网络架构,重点研究了两种技术在组网方面的不同,提出了每类技术对应的组网方式,并最后分析了WiMAX技术和McWiLL技术与现有3G网络的融合组网方案以及两种WiMAX与WCDMA网络融合方案的优缺点。     

DSRC技术及其通信机制的研究

国际上通常应用于车载通信开发的技术有DSRC技术、WiMAX技术、Wi-Fi技术等,本文深入浅出地介绍了DSRC技术的概念,着重介绍了此技术的通信原理和系统结构,阐明了DSRC技术在ITS中广泛的应用前景和发展意义,同时提出了DSRC技术中仍存在的问题。     

COM技术在构件软件中的研究与应用

分析了构件软件中有关COM技术的应用，介绍了COM技术的基本理论，对COM中的重用技术和通讯问题进行了分析，探讨了基于COM技术的ezCOM技术的应用，并对两种技术进行了分析比较。     

人工智能技术中计算机相关技术的运用解析

随着我国科学技术的迅猛发展,人工智能技术也在许多领域得到了应用。而计算机相关技术作为人工智能技术的重要技术支撑,其在人工智能技术中的应用对于技术更新以及系统升级具有重要的作用。本文从人工智能技术中计算机相关技术的发展历程出发,对人工智能技术中计算机相关技术的发展方向进行了探究,并探讨了计算机人工智能技术的应用。     

浅谈PCB贴膜不良的改善

主要讲述如何通过对不良问题的原因进行深入分析及如何通过各种交叉试验,寻找真因,制定改善措施,最终使问题得到彻底解决.     

一种主从混沌同步系统的研究及硬件实现

对一种基于主从同步的混沌同步系统进行了深入的研究.首先建立了该系统的数学模型并做出了仿真;然后在此基础上建立电路模型,并做了电路仿真;继而搭建了实际电路,通过示波器的观察,获得了满意的结果;最后对该系统应用于混沌保密通信中的可行性作出预测.     

Microwave radiometric determination of wind speed at the surface of the ocean during BESEX

Microwave radiometric measurements were made at wavelengths ranging from 0.8 to 2.8 cm at altitudes from 0.16 to 11 km under well documented meteorological conditions over the Bering Sea. It is shown that determinations of wind speed at the ocean surface and liquid water content of the clouds may be made from such data. Determinations were made from two simultaneous but independent sets of radiometric measurements. The wind speeds and liquid water contents made from these two sets showed remarkable agreement. Independent estimates of these parameters made from in situ measurements showed reasonable agreement as well.     

分布式计算技术概述

分布式计算已经广泛而又深入的参透到各行各业的科技应用中.本文对几种主要的分布式计算技术,如网格、云计算、普适计算等,做了分析和比较,同时对分布式计算目前所面临的问题做了总结.最后对分布式计算技术未来的发展方向做了展望与预测.     

Relation between splice loss and mode conversion in a graded-index optical fibre

To design an optical-transmission-line system, transmission characteristics of splices made by arc-fusion and V-groove methods were investigated experimentally for a graded-index optical fibre. It was found that the splice made by the arc-fusion method had a larger mode conversion than the splice made by the V-groove method for the same loss.     

费索激光波长计的温度补偿

论文概述了费索干涉仪型激光波长计的原理和标定。详细分析了环境温度变化使仪器参数发生微小变化；论述了ＳＩＯＭ－０１激光波长计以一种新颖的将标准激光引入测量光路的方法，随时对仪器参数实行单点标定，克服了由环境温度变化引进的测量误差。     

Portable radio antenna performance in the 150, 450, 800, and 900MHz bands `outside' and in-vehicle

Portable radio antenna performance on the human body was measured for several different radio models in the 150, 450, 800, and 900 MHz. bands. In-vehicle measurements were made at an outdoor antenna range equipped with a vehicle turntable. All other measurements were made in an anechoic chamber. Tests were made at the head level, at the side-level swivel-type carry case, at the side-level belt-loop type carry case, and at the shoulder level with a speaker microphone antenna. A statistical analysis was made of the data for use in coverage propagation predictions, and system designs. The results of the statistical analysis are presented     

Summary of conclusions of the 1992 World Administrative RadioConference

The major decisions made at the conference are briefly described. Additional frequency bands for shortwave (HF) radio broadcasting were agreed upon. Frequency allocations were made to support a number of US proposals, to provide advanced mobile radio services using low Earth orbit satellites. Allocations for land based mobile services adopted at WARC '92, in the range 1700 to 2600 MHz, are meant to foster improved mobile services that can be used worldwide. An allocation was also made to support commercial telephone service between passengers flying on aircraft and individuals on the ground. Allocations were made for sound broadcasting from satellites, as well as for providing a means to accommodate a complementary terrestrial-based digital audio broadcasting service. New frequency allocations to support space activities were agreed upon, and an allocation was made to the fixed satellite service in the band 13.75 to 14.0 GHz     

新石器时期马家窑文化彩陶的科技分析

本文采用超景深显微镜、扫描电镜（SEM）、X射线能谱仪（EDS）及X射线衍射仪（XRD）对新石器时期马家窑文化彩陶陶片的黑彩、陶衣、胎体的形貌、物相等进行了表征研究.结果表明黑色颜料以磁铁矿、软锰矿、黑锰矿为主;陶衣以白云石、石英、赤铁矿和钙长石为主;胎体以高岭土、蒙脱石类粘土为主.     

New active-gyrator circuit

Ideal passive gyrators can be made using two operational amplifiers, and it has been proved that they cannot be made with only one amplifier. However, this latter proof led to the discovery that an ideal active gyrator can be made with only one amplifier. A circuit for doing this is presented here, and its behaviour when used in an inductance-simulating mode is analysed.