Fast handoff with reducing waste rate approach for wireless resources management in UMTS mobile networks

3G Wideband CDMA systems adopt the Orthogonal Variable Spreading Factor code tree as the channelization codes management for achieving high data rate transmission in personal multimedia communications. It assigns a single channelization code for each accepted connection. Nevertheless, it wastes the system capacity when the required rate is not powers of two of the basic rate. One good solution is to assign multiple codes for each accepted connection but it causes two inevitable drawbacks: long handoff delay and new call setup delay due to high complexity of processing with multiple channelization codes, and high cost of using more number of rake combiners. Especially, long handoff delay may result in more call dropping probability and higher Grade of Service, which will degrade significantly the utilization and revenue of the 3G cellular systems. Therefore, we propose herein an adaptive efficient codes determination algorithm based on the Markov Decision Process analysis approach to reduce the waste rate and reassignments significantly while providing fast handoff. Numerical results demonstrate that the proposed approach yields several advantages, including the lowest GOS, the least waste rate, and the least number of reassignments. Meanwhile, the optimal number of rake combiners is also analyzed in this paper. This research was supported in part by the National Science Council of Taiwan, ROC, under contract NSC-93-2213-E-324-018.     

快速纳秒响应二代近贴聚焦像增强器的批量生产

叙述了二代近贴聚焦像增强器批量生产所用真空设备性能及特点，同时给出了管子工艺考核结果及管子纳秒时间响应特性。工艺考核结果表明，制管工艺可靠、性能稳定，管子批量生产合格率大于70％。     

Trace elements in particles of motor vehicle exhaust in Shanghai

A nuclear microprobe with high spatial resolution and high analytical sensitivity was applied to analyze trace elements,especially lead,in vehicle exhaust of Shanghai city.The result shows that the chemical composition and its corresponding x-ray relative intensity are different among different vehicle exhausts.There are many kinds of metal elements in particles of vehicle exhaust.most are harmful to people,such as Ti,Cr,Mn,Pb,etc.We found that the lead concentration was 6820μg/g and the bromine concentration was 5300μg/g in the exhaust from Santana using leaded gasoline(SULG).which is higher than any other kinds of vehicle exhausts.We have also detected the minimum lead in the particles of unleaded gasoline and its content varies from one to another.Its mean concentration was 450μg/g and the highest reached 6210μg/g.The unleaded gasoline‘s Pb existed in the whole particle while the leaded gasoline‘s enriched in the surface of the particle and was more harmful to the human beings.     

我国清洁代用燃料汽车发展状况

随着汽车数量的迅速增加，汽车排放的有害废气也急剧增加，人们的健康受到威胁，解决这一问题的最好办法是发展清洁代用燃料汽车。介绍了天然气汽车和液化石油气汽车的主要优点，分析了目前我国清洁代用燃料汽车的发展现状，阐述了近期适宜发展我国清洁代用燃料汽车的机遇和面临的困难。最后就提高人们的环保意识、修改和完善汽车尾气污染控制法及排放标准、清洁代用燃料汽车的有关标准和安全措施。对发展这种汽车应给予优惠政策以及零部件生产和车辆改装企业的管理等方面，提出了建议。     

Fast convergent study on potential－harmonic method of directly solving Schrodinger equation in few－body systems

Ｆａｓｔｃｏｎｖｅｒｇｅｎｔｓｔｕｄｙｏｎｐｏｔｅｎｔｉａｌ－ｈａｒｍｏｎｉｃｍｅｔｈｏｄｏｆｄｉｒｅｃｔｌｙｓｏｌｖｉｎｇＳｃｈｒｏｄｉｎｇｅｒｅｑｕａｔｉｏｎｉｎｆｅｗ－ｂｏｄｙｓｙｓｔｅｍｓＷａｎｇＹｉ－Ｘｕａｎ（王沂轩）ａｎｄＤｅｎｓＣｏｎｇ...     

液体火箭发动机研制情况的一些回顾

４０年来，我国液体火箭发动机的研制工作取得了很大成绩。文中对发动机的一些研制情况作了回顾，对ＹＦ－７３和ＹＦ－７５氢氧发动机的设计特点、飞行结果作了简单叙述。对今后工作也提出了看法。     

SISAK快速化学分离装置的建立

SISAK(Short-lived Isotopes Studies by the AKUFVE technique)技术是目前使用最广泛的快速化学分离方法之一,主要应用在短寿命核素的分离和鉴别、超重元素的人工合成以及化学性质研究等方面的工作中.本文简单地叙述了SISAK技术的流程、原理和发展现状,介绍了自行建立的国内第一套基于SISAK技术的快速化学分离装置,并通过从裂变产物中分离短寿命核素这一实例验证了SISAK技术在快速化学分离中的优越性.     

检测骨架图形特征点的新方法

端点、折点、歧点和交点是骨架图形的重要特点是，提出用快速查表法检测侯选特征点，再进行侯选特征点聚集，用局部结构分析，去除假特征点，判别真特征点的类型，并对折点给以大致的定量描述。实验结果表明，该方法能快速有效地找出骨架图形的特征点，在目标识别、字符识别等应用中起着关键作用。     

一步法合成松香改性酚醛树脂

探讨了一步法合成松香改性酚醛树脂的反应机理，确定了最佳原料组成及合成工艺，由此制备出高溶解粘度和矿油容纳度的松香改性酚醛树脂，是一种性能优异的高级胶印油墨连接料     

高纯锗探测器的快定时性能及其应用

为了将高纯锗（ＨＰＧｅ）探测器用于快定时的物理实验中，本实验研究厂影响高纯锗探测器定时谱仪时间性能的各种因素，找出了获得谱仪最小时间分辨的各种最佳参数。并建立了分辨时间为４．１９ｎｓ，能量分辨率为２０ｋｅＶ，微分非线性好于±２．０％，计效率可承受１２０×１０￣３ｓ￣（－１）的时间微分扰动角关联谱仪。利用此谱仪，以￣（２０４）Ｂｉ为探针核，研究了Ｂｉ系高温超导的微观机理，取得了较好的结果。