Multiple-symbol detection of MPSK in narrow-band interference andAWGN

We propose a new technique for rejection of narrow-band interference (NBI) based on multiple-symbol detection of coherent or differential phase-shift keying (DPSK). We first show that the direct use of multiple-symbol detection offers poor performance when NBI is dominant. Our proposed technique employs a special signaling or coding scheme which is shown to be robust against NBI. The evaluation of bit-error rate (BER) shows significant performance improvement in NBI vis-a-vis direct multiple-symbol detection. When viewed as a coding scheme, the proposed signaling scheme is significantly simpler for achieving the same coding gain than conventional error correction codes     

多级放大频分复用系统中四波混频串扰的消除

本文从理论上研究了四波混频在多级放大频分复用光通信系统中的特性，提出了一种消除四波混频串扰的新方法，该方法只需适当选择信道间隔，无需增添其它器件，因而更有利于在实际光通信系统当中的应用。     

Phase equilibria in InAsSbP quaternary alloys grown by liquid phase epitaxy

The quaternary alloy InAs_1−x−ySb_xP_y, lattice-matched to InAs, is a promising material for the production of infrared light sources for the detection of gases in the 2–4 μm region of the spectrum. In this work, thermodynamic phase equilibrium calculations have been carried out to determine the compositions required for liquid phase epitaxial growth and the extent of the miscibility gap in the solid material. For high band gap materials, the desired growth temperature is found to be intermediate between a low temperature required to grow P-rich solids and higher temperatures required to avoidspinodal decomposition. Conventional LPE growth at an intermediate temperature of 583°C is found to produce good material with high luminescence efficiency and excellent optical characteristics. Problems with phosphorus loss from the melt are also discussed and lower growth temperatures are found to considerably reduce this problem. Growth in the metastable region between the binodal and spinodal lines has been achieved with the production of phosphorus-rich solids with concentrations up to y = 0.445.     

紫外激光无损检测潜在指印技术研究

潜在指印的显现是物证检验技术中的关键问题之一,而紫外(UV)照相技术是显现潜在指印等隐性痕迹物证的重要技术手段。采用266 nm紫外固体激光器为激发光源,利用人体指印固有物质成分对紫外光具有特殊的吸收、反射、散射及荧光特性,减弱或消除指印背景上的图案和其他细节干扰,增加指印纹线与背景的亮度反差,显出或增强潜在指印。通过紫外反射照相及紫外固有荧光照相技术,分别实现了对彩色杂志纸张、玻璃、电话背面、木纹桌面油漆面4种非渗透性物证检材及牛皮纸信封、便签纸2种渗透性物证检材表面遗留的新鲜及陈旧潜在指印的无损检测显现,并具有鉴定价值。     

大型水利枢纽发电—航运优化日运行

本文研究河流主航道上大型水利枢纽的发电-航运优化日运行方式,提出决规划阶段问题和运行阶段问题的两个数学模型及其求解方法。以长江三峡-葛洲坝梯级水电站为实例进行了计算,得出初步结果。     

谐波随机过程的高阶平稳性和高阶遍历性条件

本文分析了由随机谐波构成的复信号高阶矩的有限数据估计，得到了高阶平稳和高阶遍历条件，给出了估计误差及其方差，以及它们大样本极限值的显式表达式。最后考虑了文献［２］中的情形，说明文献［２］中所得结果为本文的特例。     

基于巴特沃斯逼近的二维IIR数字滤波器的设计

本文给出了一种基于巴特沃斯逼近的二维ＩＩＲ数字滤波器的设计方法，得到了由基本的全通节级联，并联实现的各种二维滤波器函数，包括，镜象对称互补滤波器，扇形滤波器和具有任意矩形通、阻带的滤波器，结果表明，这种实现结构具有通有灵敏度低、滤波器系数少的优点，并且由于巴特沃斯逼近的最大平坦性，得到的滤波器具有良好的相位特性。     

ZnO 晶须/Ni-Zn 铁氧体复合材料对电磁波阻抗及反射能力研究

研究了ＺｎＯ晶须与Ｎｉ－Ｚｎ铁氧体复合材料在１～１０００ＭＨｚ范围内的阻抗和对电磁波的反射能力。结果表明，复合材料的阻抗随ＺｎＯ晶须含量增加先急剧下降，后趋于恒定，这是由于复合材料的导电网络形成后，其电导率就逐渐趋于恒定的原因。反射能力随低阻抗ＺｎＯ晶须的增加逐渐增加，且也因阻抗逐渐恒定而趋于恒定。     

Aromatization of n-butane over new LD-HBS catalysts. Effect of the gallium oxide support

It is shown that even pure quartz, other silicas or aluminas can enhance the aromatization activity of a ZSM-5 zeolite. Incorporation of gallium oxide onto these supports increases further the production of aromatics. The use of supported gallium oxide co-catalyst obtained by co-evaporation of a colloidal silica and a Ga salt has led to extremely high aromatization performance for the hybrid catalyst.