Groups of algebraic integers used for coding QAM signals

Linear block codes over Gaussian integers and Eisenstein integers were used for coding over two-dimensional signal space. A group of Gaussian integers with 2²ⁿ elements was constructed to code quadrature amplitude modulation (QAM) signals such that a differentially coherent method can be applied to demodulate the QAM signals. This paper shows that one subgroup of the multiplicative group of units in the algebraic integer ring of any quadratic number field with unique factorization, modulo the ideal (Pⁿ), can be used to obtain a QAM signal space of 2p^2n-2 points, where p is any given odd prime number. Furthermore, one subgroup of the multiplicative group of units in the quotient ring Z[ω]/(pⁿ) can be used to obtain a QAM signal space of 6p^2n-2 points; one subgroup of the multiplicative group of units in the quotient ring Z[i](pⁿ) can be used to obtain a QAM signal space of 4p^2n-2 points which is symmetrical over the quadrants of the complex plane and useful for differentially coherent detection of QAM signals; the multiplicative group of units in the quotient ring Z[ω]/(2ⁿ) can be used to obtain a QAM signal space of 3·2^2n-2 points, where i=√-1, ω=(-1+√-3)/2=(-1+i√3)/2, p is any given odd prime number, Z[i] and Z[ω] are, respectively, the Gaussian integer ring and the Eisenstein integer ring. These multiplicative groups can also be used to construct block codes over Gaussian integers or Eisenstein integers which are able to correct some error patterns     

非球面塑料透镜注射型芯工艺探讨

本文来自于作者的实践。介绍了加工方法及测量问题。重点叙述了加工中的一些关键,同时也提供了国内外在这方面的进展情况。     

Isolation and Structure Elucidation of Nortriterpenoids from Schisandra rubriflora

Seven new highly oxygenated nortriterpenoids, rubriflorins D–J ( 1 – 7 ), were isolated from the leaves and stems of Schisandra rubriflora, and their structures were elucidated on the basis of extensive analysis of spectroscopic data. These new compounds feature the opening of ring A compared with related known nortriterpenoids isolated from the genus Schisandra and showed weak activity against HIV‐1.     

采用级联原子滤光器的新型卫星激光链路系统研究

提出级联佛克脱型原子滤光器(Linked VADOF)的新构想。从理论上分析并计算了级联佛克脱型原子滤光器的透射谱。结果表明，级联佛克脱型原子滤光器将佛克脱型原子滤光器的多峰改造为单峰结构，具有比佛克脱型原子滤光器更窄的线宽和更高的噪声抑制比。将这种新型结构应用于激光信标锁频。该锁频方案提高了信标光频率的稳定性。在此基础上，给出了发射端采用级联佛克脱型原子滤光器锁频，接收端采用法拉第型原子滤光器(FADOF)滤光的新型卫星激光链路系统。外场初步联调实验表明了该系统的可行性。     

Hg_（1－x）Cd_xTe的扫描光致发光研究

用傅里叶变换红外扫描光致发光方法研究了Ｈｇ１－ｘＣｄｘＴｅ体单晶样品，该方法可直接得到ＨｇＣｄＴｅ晶片组分的二维平面分布，并可得到辐射复合在复合机制中所占比重的平面分布，以及晶体中非平衡载流子寿命的分布     

光纤通信在军事上的应用

简述了光纤通信在军事通信中的地位与作用，较全面介绍了陆、海、空军各领域的应用情况，阐明了军事通信对光纤通信元器件的要求和核爆炸对光纤通信的影响。     

SCLC法测量非晶硅有效隙态密度

提出了用空间电荷限制电流（SCLC）法测量非晶硅材料的有效隙态密度的新方法，并且报告了用4061A型半导体综合测试仪测量有效隙态密度的结果。测量结果发现与用低频电容法所得结果相符。     

TiO2 粉末催化剂光催化降解室内 空气中有机污染物

本文制备了一系列 TiO2粉末催化剂, 用光催化法降解室内空气中各种微量有机污染物,最终降解率 接近 100%. 考察了晶型对光催化剂性能的影响, 结果表明,锐钛矿型 TiO2 的催化性能最好. 最后,分析了 TiO2 光催化反应机理.     

醇体系中合成CuGaS2纳米晶及其形貌演变

以CuCl2·2H2O,自制的GaCl3和(NH2)2CS为原料,在乙二醇体系中合成了花状结构的CuGaS2纳米晶．产物分别用X射线粉末衍射仪、透射电子显微镜、场发射扫描电子显微镜、高分辩透射电子显微镜和X射线光电子能谱仪进行了表征．实验结果表明,220℃反应24 h得到均匀的花状纳米结构CuGaS2,它是由厚度80-100 nm的片晶组成．同时,通过反应时间的控制,可以清楚的看到由纳米颗粒到纳米球以及花状纳米结构的演变过程．另外,研究了反应温度、反应时间、溶剂等对产物和形貌的影响．此外,对花状结构纳米晶的生长机理进行了初步的探讨．室温荧光光谱表明,随粒径的降低,发光位发生了部分蓝移．     

水合乙酸锌脱水反应的动力学

用等温热重法和非等温热重法研究了Zn(CH3COO) 2·2H2 O的脱水反应 .在 61.1、62 .8、66.2、69.9℃下的等温热重数据 ,由等转化率下的lnt=E/RT +ln[g(α) /A]进行拟合 ,确定了活化能的大小 ;升温速率为 10℃ /min的非等温热重曲线显示 ,Zn(CH3COO) 2·2H2 O的脱水反应发生在 71～ 10 2℃间 ,其数据通过Doyle Zsako法进行拟合 ,以线性相关系数为判据 ,并结合等温热分析拟合结果 ,得到该脱水反应的积分动力学模式函数g(α) =[-ln( 1-α) ]2 / 3、活化能E =10 0 .8kJ/mol、指前因子ln(A/s-1) =3 6.0 9、动力学补偿效应方程为lnA =0 .3 3 3 9E + 2 .0 10 .