Magneto-optical Enhancement Effect in MnBi_xAl_(0.15) Films

ＭａｇｎｅｔｏｏｐｔｉｃａｌＥｎｈａｎｃｅｍｅｎｔＥｆｅｃｔｉｎＭｎＢｉｘＡｌ０１５ＦｉｌｍｓＣ．Ｈ．ＳｈａｎｇＹ．Ｊ．Ｗａｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＰｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００８０）...     

基于强Universal2函数的消息认证码构造与安全性分析

基于强Ｕｎｉｖｅｒｓａｌ_２函数的消息认证码构造与安全性分析ＴｈｅＣｏｎｓｔｒｕｃｔｉｏｎａｎｄＳｅｃｕｒｉｔｙＡｎａｌｙｓｉｓｏｆＭｅｓｓａｇｅＡｕｔｈｅｎｔｉｃａｔｉｏｎＣｏｄｅＢａｓｅｄｏｎＳｔｒｏｎｇＵｎｉｖｅｒｓａｌ_２Ｆｕｎｃｔｉｏｎ￥朱华...     

PSpice Modeling of Opto-electronic devices Using ABM Components

ＰＳｐｉｃｅＭｏｄｅｌｉｎｇｏｆＯｐｔｏ┐ｅｌｅｃｔｒｏｎｉｃｄｅｖｉｃｅｓＵｓｉｎｇＡＢＭＣｏｍｐｏｎｅｎｔｓＪｉａｎｐｉｎｇＣＨＥＮＤｉｅｔｅｒＳＴＯＬＬ１（ＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｙｏｎＬｏｃａｌＦｉｂｅｒ－ＯｐｔｉｃＣｏｍｍｕｎｉ...     

解析SiGe基极HBT模型及其对BiCMOS倒相器电路的影响

解析ＳｉＧｅ基极ＨＢＴ模型及其对ＢｉＣＭＯＳ倒相器电路的影响＝ＡｎＡｎａｌｙｔｌｃａｌＳｉＧｅ－ｂａｓｅＨＢＴｍｏｄｅｌａｎｄｉｔｓｅｆｆｅｃｔｓｏｎａＢｉＣＭＱＳｉｎｖｅｒｔｅｒｃｉｒｃｕｉｔ［刊．英］／Ｌｕ，Ｔ．Ｃ．…／ＩＥＥＥＴｒａｎｓ．Ｅｌｅ...     

A New Optical Fiber Loop System Used in Measurement of Dispersion Compensation Ability

ＡＮｅｗＯｐｔｉｃａｌＦｉｂｅｒＬｏｏｐＳｙｓｔｅｍＵｓｅｄｉｎＭｅａｓｕｒｅｍｅｎｔｏｆＤｉｓｐｅｒｓｉｏｎＣｏｍｐｅｎｓａｔｉｏｎＡｂｉｌｉｔｙＭａｎｕｓｃｒｉｐｔｒｅｃｅｉｖｅｄＤｅｃ．２４，１９９６．ＳｕｐｐｏｒｔｅｄｂｙＫｅｙＰｒｏｊｅｃｔ...     

Structural and Electrical Behaviors of Ag Films Deposited on Liquid Substrates

ＳｔｒｕｃｔｕｒａｌａｎｄＥｌｅｃｔｒｉｃａｌＢｅｈａｖｉｏｒｓｏｆＡｇＦｉｌｍｓＤｅｐｏｓｉｔｅｄｏｎＬｉｑｕｉｄＳｕｂｓｔｒａｔｅｓＧ．Ｘ．Ｙｅ１，２Ｑ．Ｒ．Ｚｈａｎｇ２Ｈ．Ｌ．Ｇｅ２Ｃ．Ｍ．Ｆｅｎｇ２（１Ｄｅｐｔ．ｏｆＰｈｙｓ．，Ｈａｎｇｚｈ...     

Spatial Light Modulator with BSO Crystal and Its Application in Holography

ＳｐａｔｉａｌＬｉｇｈｔＭｏｄｕｌａｔｏｒｗｉｔｈＢＳＯＣｒｙｓｔａｌａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎｉｎＨｏｌｏｇｒａｐｈｙ①ＷＡＮＧＷｅｎｓｈｅｎｇ（ＣｈａｎｇｃｈｕｎＣｏｌｅｇｅｏｆＯｐｔｉｃｓａｎｄＦｉｎｅＭｅｃｈａｎｉｃｓ，Ｃｈａｎｇｃｈ...     

Optical PPM CDMA Communication System with Optical Hard Limiter

1　ＩｎｔｒｏｄｕｃｔｉｏｎＯｐｔｉｃａｌＣｏｄｅＤｉｖｉｓｉｏｎＭｕｌｔｉｐｌｅＡｃｃｅｓｓ (ＯＣＤ ＭＡ)ｃｏｍｍｕｎｉｃａｔｉｏｎｓｙｓｔｅｍｓｈａｖｅｂｅｅｎａｔｔｒａｃｔｉｎｇａｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｒｅｃｅｎｔｌｙ .Ｔｈｉｓｉｓｄｕｅｔｏｔｈｅｖａｓｔｂａｎｄｗｉｄｔｈｉｎｔｈｅｏｐｔｉｃａｌｌｉｎｋｓａｎｄｔｈｅｅｘｔｒａ ｈｉｇｈｏｐｔｉｃａｌｓｉｇｎａｌｐｒｏｃｅｓｓｉｎｇｓｐｅｅｄｗｈｅｎｕｓｉｎｇｏｐｔｉ ｃａｌｃｏｍｐｏｎｅｎｔｓ.Ｍｏｓｔｒｅｓｅａｒｃｈｗｏｒ…     

美国AEM公司公布成立AEM／WALLACE分公司

美国ＡＥＭ公司公布成立ＡＥＭ／ＷＡＬＬＡＣＥ分公司应ＷａｌｌａｃｅＴｅｃｈｎｉｃａｌＣｅｒａｍｉｃｓ董事局邀请，入选１９９４年度“全美成长最快５００名私营企业”（ＩＮＣ．５００）排行榜的ＡＥＭ公司公布收编美国ＷＴＣ的Ｍｒ．Ｂｉｍ＆ＫｅｎＷａｌｌａｃｅ...     

Measuring System for Interference Optical Fiber Acoustic Emission

ＭｅａｓｕｒｉｎｇＳｙｓｔｅｍｆｏｒＩｎｔｅｒｆｅｒｅｎｃｅＯｐｔｉｃａｌＦｉｂｅｒＡｃｏｕｓｔｉｃＥｍｉｓｉｏｎ①ＬＵＱｉｚｈｕ，ＺＨＥＮＧＳｈｅｎｇｘｕａｎ（ＹａｎｓｈａｎＵｎｉｖｅｒｓｉｔｙ，Ｑｉｎｈｕａｎｇｄａｏ０６６００４，ＣＨＮ）Ａｂｓｔ...     

Theoretical Bounds and Practical Constructions for Families of One—Coincidence Sequences in FHMA

Theoretical bounds are given for the number of one-coincidence sequences in syn-chronous FHMA systems,and for the number and period of one-coincidence sequences in asyn-chronous FHMA systems.Several practical constructions for families of one-coincidencesequences are surveyed,and a new model for families of one-coincidence sequences is presented.     

跳频序列设计理论的研究进展

跳频技术具有抗干扰和多址组网性能，在军事无线电通信、民用移动通信、现代雷达和声纳等电子系统中具有重要的应用。跳频序列用于控制载波频率随机时间的变化规律，其性能对跳频系统的性能有重大影响。本文综述跳频序列设计理论的研究成果，并指出今后的发展方向。     

基于分组密码的跳频序列多址接入性能分析

基于3DES迭代型分组密码产生的跳频序列,构造了一种跳频组网的随机多址接入方案模型。在此基础上分析了跳频码分多址的系统接入性能,从理论上推导出跳频图案碰撞引起的误分组率、跳频组网的吞吐量和归一化吞吐率,证明数据分组长度M与可用频隙数q的比值是决定跳频码分多址系统性能的重要因素。计算机仿真结果验证了理论的正确性,同时也证明了基于分组密码的跳频序列具有较好的跳频多址组网性能。     

Optimal frequency hopping sequences: a combinatorial approach

Frequency hopping multiple access (FHMA) spread-spectrum communication systems employing multiple frequency-shift keying (MFSK) as data modulation technique are investigated from a combinatorial approach. A correspondence between optimal frequency hopping (FH) sequences and partition-type difference packings is first established. By virtue of this correspondence, FHMA systems with a single optimal FH sequence each are constructed from various combinatorial structures such as affine geometries, cyclic designs, and difference families. Combinatorial recursive constructions are also presented. Many new infinite series of optimal FH sequences are thus obtained. These new FH sequences are also useful in ultra wideband (UWB) communication systems.     

Upper bound on one-coincidence sequences of odd length with distance constraints in frequency-hopping spread-spectrum systems

We deal with one-coincidence sequences for the frequency-hopping CDMA systems. We derive an upper bound on the number of one-coincidence sequences of odd length where the distances between all adjacent frequency indices are required to be greater than a specified distance value. It is shown that there exist infinitely many cases in which our bound is tighter than the conventional bound.     

有限精度混沌映射跳频多址序列

跳频地址码的性能对跳频多址通信系统的性能起着关键性的作用.把混沌系统引入跳频通信系统可以得到大量性能良好的跳频地址码,但是数字计算中的有限精度效应会使混沌系统的性质恶化.这里提出以m序列扰动在双精度计算条件下产生跳频多址序列,对序列的性质进行了研究.     

Analysis of FHMA performance on block cipher based frequency-hopping sequences

Based on the triple Data Encryption Standard (DES) block cipher frequency-hopping (FH) sequences, a kind of packet protocol for frequency-hopping multiple-access (FHMA) network is suggested in this paper. In theory, the performances of both the packet error and the throughput are derived, which shows that the ratio of the packet length M to the frequency slots number q is most key parameter to determine the FHMA system performance under the condition of large user number. Computer simulation results of 3-DES FH sequences compared with those of the chaotic FH sequences are also included to support our developments.     

Residue number system assisted fast frequency-hopped synchronous ultra-wideband spread-spectrum multiple-access: a design alternative to impulse radio

Ultra-wideband (UWB) systems having a bandwidth on the order of gigahertz have received wide attention both in the US and in Europe. The family of UWB systems may communicate either, by generating ultra-wideband signals or with the aid of innovatively combining conventional narrowband, wideband, or broadband signals. At the time of writing, UWB systems have only been implemented using ultra-wideband signals, such as those known from impulse radio systems. Hence, in this paper, UWB systems using narrowband signals are explored as a design alternative, which are based on the well-known family of frequency-hopping (FH) spread-spectrum multiple-access techniques. In the proposed UWB system, FH is implemented using multistage frequency-hopping multiple access (MS/UWB FHMA). We highlight the principles of the synchronous MS/UWB FHMA communication system, investigate the associated spectrum assignment, and the residue number system (RNS) based FH strategy: detection of the received signal can be achieved with the aid of existing fast FH signal detection schemes. Our study shows that the RNS assisted FH strategy is capable of efficiently dividing the huge number of users supported by the synchronous MS/UWB FHMA system into a number of reduced-size user groups, where the multiuser interference only affects the users within the same group. Since the number of users in each group is only a small fraction of the total number of users supported by the synchronous MS/UWB FHMA system, advanced multiuser detection algorithms can be employed for achieving near-single-user performance at an acceptable complexity. Our results show that MS/UWB FHMA is capable of supporting an extremely high number of users, while employing relatively simple receivers.     

非重复跳频序列族的理论限制

本文讨论跳频多址组网用的非重复序列族的理论限制,得到了限定汉明相关条件下非重复序列族中序列数目和序列长度的理论限,列举了几种达到了理论限的非重复跳频序列族。     

一类新的宽间隔跳频序列族的构造

基于GF（p)上的m序列构造的最佳跳频序列，提出了一种宽间隔跳频序列族的构造方法。通过理论推导和计算机模拟，表明该宽间隔跳频序列族具有较好的汉明相关性能，略差于最佳跳频序列族。