产生2元de Bruijn序列的一个新算法

２元ｎ级ｄｅＢｒｕｉｊｎ序列是由ｎ级移位寄存器产生的周期为２ｎ的移位寄存器序列，给出了２元ｄｅＢｒｕｉｊｎ序列的一个新的生成算法，该算法能生成２ｓ·ｇ（ｎ，ｓ）个ｎ级如ｄｅ　Ｂｒｕｉｊｉｎ序列，其中，０≤ｓ≤２（ｎ－７）／３；当 ２ｌ－１＜ｓ≤２Ｌ时，ｇ（ｎ，ｓ）＝ｎ－３Ｌ－６－［（ｎ－２Ｌ－６）／（Ｌ＋１）］。     

关于M序列的自相关函数的一点注记

本文讨论了Ｍ序列的自相关性，并证明了：当０＜｜ｔ－２＾ｎ－１｜≤［ｎ－１／２］时，｜ＣＭ（ｔ）｜≤２＾ｎ－１。     

关于本原M序列的一些自相关函数取值

本文讨论了由ｍ序列叠加小项ｘ２…ｘｎ构成的Ｍ序列的自相关性能，获得了ｃ（ｎ＋１）＝－４或０或４，ｃ（τ１）＝－４，ｃ（τ２－１）＝０或４（τ１和τ２意义见定理１）的新结果，同时并给出了ｃ（ｎ＋ｋ）（ｋ≥２）的可能取值范围。     

TEA CO_2序列带激光

ＴＥＡＣＯ２序列带激光序列带ＣＯ２激光属０００ｎ－［１００（ｎ－１），０２０（ｎ－１）］，ｎ≥２的跃迁。较易实现的是０００２－［１００１，０２０１］跃迁，可使ＣＯ２激光谱线数增加一倍，且不会被ＣＯ２气体吸收。在选择性光物理与光化学、激光光谱、光泵激光...     

线性拟等重码的结构分析

Ｃ为二元正侧线性拟等重码，我们证明：（１）如果ｎ＝２ｄ则Ｃ等价于１阶；（２）如何为素数，则Ｃ等价于ＲＭ（ｋ－１）删除第１个分量后得到的线性码，另外，利用编码理论中著名的Ｍａｃ Ｗｉｌｌｉａｍ恒等式给出文（１）定量１的一个新的简洁证明。     

RuO_2－Ag低阻浆料中掺入MnO_2、V_2O_5杂质改善电阻特性

ＲｕＯ_２－Ａｇ低阻浆料中掺入ＭｎＯ_２、Ｖ_２Ｏ_５杂质改善电阻特性宋兴义（昆明贵金属研究所昆明６５０２２１）为了改善ＲｕＯ２－Ａｇ系低阻浆料的电阻温度系数，大多采用在电阻浆料中掺入表１掺ＭｎＯ２的ＲｕＯ２－Ａｇ电阻浆料配方ＭｎＯ２、Ｖ２Ｏ５、Ｎｂ２Ｏ...     

新型厚膜片式NTC热敏元件研究

作者以Ｍｎ（１＋ｘ）Ｃｏ（２－ｘ）Ｏ４作热敏基料，掺适量ＭｅＭｎ２Ｏ４添加物，有效地降低了热敏浆料的方组，改善了元件的热稳定性，使厚膜片式ＮＴＣ热敏元件达到了实用化的要求。     

La—Ca—Mn—O薄膜的巨磁效应

报道了Ｃａ掺杂量对Ｌａ－Ｃａ－Ｍｎ－Ｏ巨磁薄膜材料的巨磁效应影响，测量薄膜电阻（外磁场强度Ｈ＝０．５Ｔ）磁化强度，温度关系曲线，认为Ｌａ１－ｘＣａｘＭｎＯ３体系中Ｍｎ＾４＋的含量是由于掺杂量Ｃａ的调制Ｍｎ＾４＋的含量变化导致磁性结构转变，用双交换模型解释了该象现，对实验给出满意的解释。     

热压烧结对Co－Mn－Ni－O热敏材料电性能的影响

研究了不同热压压力、热压方式对Ｃｏ－Ｍｎ－Ｎｉ－Ｏ热敏材料电性能的影响。热压烧结能够提高材料的电阻率及Ｂ值。Ｘ射线衍射分析表明，热压烧结材料有ＭｎＣｏ２Ｏ４、ＮｉＭｎ２Ｏ４和ＣｏＮｉＯ２三相组成。从扫描电镜照片可见，热压烧结材料晶粒细小、均匀、气孔率少，是提高其电性能的主要原因。调整热压压力可以有效地控制材料的电学参数     

创新推出8倍速DVD-ROM套件

创新公司的ＤＶＤ－ＲＯＭ套件又将升级,配备８倍速ＤＶＤ－ＲＯＭ的ＰＣ－ＤＶＤＥｎｃｏｒｅ８Ｘ即将上市。ＰＣ－ＤＶＤＥｎｃｏｒｅ８Ｘ套件包括一个８ＸＤＶＤ－ＲＯＭ和一块采用Ｄｘｒ３技术的ＭＰＥＧ２解压缩卡,能提供效果上佳的硬件ＭＰＥＧ２解压缩的影音播放效果。创新的ＤＸＲ３（ＤｙｎａｍｉｃＸｔｅｎｄｅｄＲｅｓｏｌｕｔｉｏｎ３）技术,除了能完成硬件ＭＰＥＧ２解压缩外,还可将ＤＶＤ影片普遍使用的ＡＣ－３５．１声道数码音效输出,再通过ＡＣ－３解码器由５．１声道音箱输出相当于影院的效果,该卡还配有Ｓ／ＰＤＩ…     

Ternary sequence with zero correlation

A method of generating ternary sequences with zero cyclic correlation except for the spike for zero lag is described. The sequences are of length given by (3ⁿ-1)/2 where n is odd. A method of generating uncorrelated sequences derived from the ternary sequence modified by a Hadamard matrix is indicated.     

产生k元M序列的一种新算法

本文给出了生成k元M序列的一种新的算法.该算法不再采用主圈并一个圈的经典并圈法,而是利用了主圈并一组共轭圈的新的并圈方法.这样减少了选择桥状态的次数,进而加快了并圈速度.     

A NEW ALGORITHM FOR THE GENERATION OF k-AKY M SEQUENCES

A new algorithm for generating k-ary M sequences is given. In the algorithm a new method is used that the main cycle is extended by joining to it a subset of cycles instead of the classical one in which the main cycle is extended by joining to it one cycle. The algorithm reduces the times of choosing bridging states and accelerates the speed of joining cycles.     

余弦映射法产生混沌跳频序列及宽间隔的改进

提出了一种基于余弦映射法产生十进制混沌跳频序列的方案，并对此方案所产生的十进制混沌序列在跳频通信系统中的性能进行了分析，包括用C语言进行模拟计算，使性能达到良好。在此基础上，通过查表和使用DSP使该方案得到落实并结合对偶宽间隔法产生了宽间隔的跳频序列，使跳频间隔得到了大大的改善。     

广义映射混沌扩频序列及其特性分析

该文从扩频通信对扩频码序列的要求出发,提出采用广义映射产生混沌数字序列的思路。通过对广义映射混沌数字序列相关性和平衡性的分析,给出一种改进的广义映射混沌数字序列生成方法。计算机模拟分析表明,使用该文方法生成的混沌序列具有良好的平衡性和保密性,更适合在码分多址通信中应用。     

Design of sequence set with group-wise zero correlation window

Zero correlation window (ZCW) or zero correlation zone (ZCZ) sequence can be used in quasi-synchronous code division multiple access (QS-CDMA) system to eliminate multiple access and multipath interferences. However, as the length of ZCW or ZCZ increases, fewer sequences are available. Recently, a new concept, sequence set with group-wise zero correlation window is introduced, which can increase the number of available sequences for a QS-CDMA system. In this article, a new method for generating sequence set with group-wise zero correlation window is presented. This method is based on a Hadamard matrix of size N×N and a pair of Hadamard matrices of size M×M. Compared with previous methods, the proposed sequence set has a group-wise zero correlation window for both periodic and aperiodic cross-correlation functions.     

By the numbers

We have presented two methods for generating i.i.d. standard Gaussian random variates, given a function that generates i.i.d. uniform random variates. Given modern computer hardware and software libraries, the Box-Muller transform is likely to be slightly more efficient than the inverse-transform method. Both are very simple to program, provided, in the latter case, that one already has available one of the high-accuracy approximations to F_x ^-1. The inverse-transform method also has appeal in particular specialized applications of Monte Carlo simulation. We have also briefly presented methods for generating i.i.d. sequences of bivariate Gaussian random vectors with correlation p, as well as general multivariate Gaussian random vectors.     

Code modulation of m-sequences

A family of binary sequences exists with the property that the cross-correlation function of each member with a reference m-sequence has a unique pattern of four peaks with equal offsets from a constant base level. The positive peak is position invariant and knowledge of the locations of the remaining three peaks, which are negative, identifies the sequence. A simple method for generating the sequences is given and an application in the form of a system for data transmission by code modulation of an m-sequence carrier is proposed.     

Sequences and codes with asymmetrical runlength constraints

Presents a generating function for runlength limited sequences intended for binary asymmetrical channels. The channel capacity for such channels is derived from this generating function. The authors furthermore present selected numerical values of channel capacity for these sequences. An expression for the power spectrum of binary maxentropic asymmetrical sequences is given and the influence of the asymmetry on the spectrum is investigated, Two new runlength limited modulation codes which are suitable for use on binary asymmetrical channels are investigated     

N-shift cross-orthogonal sequences

N-shift cross-orthogonal sequences and a complete complementary code derived from them are defined and discussed. A general method for generating this code is also discussed. A synchronous multiple-user spread-spectrum multiple system is proposed that uses N-shift cross-orthogonal sequences