干扰条件下的“北斗”信号解扩重构DOA估计

在干扰条件下，卫星导航抗干扰波束形成算法往往需要卫星信号波达方向（Direction-of-Arrival，DOA）的先验信息。但当存在低信噪比信号或主动干扰源时，常规的DOA估计算法性能急剧下降甚至失效。针对此问题，提出了一种被干扰信号压制的低信噪比“北斗”信号的DOA估计算法。该算法首先通过对接收信号进行子空间投影抑制干扰信号，然后对抑制干扰后的信号进行解扩重构处理，最后通过多重信号分类算法完成对“北斗”信号的DOA估计。仿真结果表明，在干扰信号干信比80 dB条件下，“北斗”信号DOA估计误差在5°以内，为下一步进行波束形成计算提供了高精度的入射角信息。     

氧化铝陶瓷缺口件循环疲劳及断裂机理

用实验方法研究了Ａｌ＿２Ｏ＿３陶瓷缺口试件在循环载荷作用下的疲劳寿命。结果表明，缺口导致的应力集中效应显著降低了循环疲劳寿命；若用缺口根部最大应力为应力水平，则不同缺口半径陶瓷试件具有相同疲劳断裂规律，说明陶瓷材料的疲劳集中系数和理论应力集中系数相同。本文还分析讨论了陶瓷材料的循环疲劳寿命表达式和循环疲劳断裂机理。     

场顺序彩色显示器

荫罩CRT受自身结构的限制,要进一步改进其分辨率就有很大的困难。近年已研制成一种获得彩色图像的颇有吸引力的替代品,即场顺序彩色显示器。它由单色CRT和液晶电子色闸组成,称之为LC/CRT系统。液晶电子色闸由液晶π盒及其连用的偏振片组成,可看成是老式机械彩色轮那样的一种电控色带带通滤色片。本文描述了液晶电子色闸的功能及其工作优点,讨论了其可能结构与显示特性。     

一种新的TDRSS扩频调制方式的研究

本文讨论跟踪及数字中继卫星系统（TDRSS）一种新通信体制，即并行MSK扩频系统，发射端采用长短码正交扩频的平衡调制，接收端采用一种简单解扩方式简化了并行MSK信号的解调，同时用短码全“1”引导长码同步的方法大大减小了长码的捕获时间，实验结果证明了良好的伪码同步性能。     

金刚石膜的计算机虚拟制备技术中的分子动力学模拟

综述了近年来金刚石薄膜形成过程的分子动力学（Molecular Dynamics，简称MD）模拟研究，详细地阐述了原子间相互作用势的选取，总结了不同沉积条件下MD的计算模型和几种典型情况下的模拟结果。研究表明：在原子尺度上，MD方法能较全面地提供有关膜生长的信息，对进一步了解金刚石膜形成的微观机制以及为细观层次仿真提供基本信息均具有重要意义。     

An artificial intelligent diagnostic system on differential recognition of hematopoietic cells from microscopic images

The endothelium participates actively in homeostatic mechanisms such as the regulation of vascular tone and maintenance of a nonthrombotic environment, as well as directing biological responses such as leukocyte trafficking to inflammatory sites. Disruption of these processes leads to disease. In the antiphospholipid antibody syndrome autoantibodies provoke the endothelium to develop a prothrombotic surface. In systemic vasculitides associated with presence of antineutrophil cytoplasm antibodies, it is likely that the autoantibodies incite premature neutrophil activation, disrupted neutrophil-endothelium interactions and endothelial damage. This review considers how normal endothelial functions may be subverted in disease and how active endothelial responses may contribute to disease.     

An outbreak of malignant catarrhal fever in young rusa deer (Cervus timorensis)

On the basis of clinical signs and histological findings eight 9-month-old male rusa deer (Cervus timorensis) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5 degrees C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested polymerase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer.     

Early and late postinfarct dilatation of the left ventricle: the connection to electrophysiological disorders and the risk of developing ventricular tachyarrhythmias

The aim of the study was to discover determinants of the onset of life threatening ventricular tachyarrhythmia. 102 patients with acute myocardial infarction and 32 patients with postinfarction cardiosclerosis were examined. The data gained at programmed ventricular stimulation, high resolution ECG, Holter ECG monitoring, spectral analysis of cardiac rhythm variability and two-dimension echocardiography proved the importance of early postinfarction left ventricular dilatation in the onset of electrical cardiac instability, establishment of anatomic substrate of monomorphic ventricular tachycardias, low variability of cardiac rhythm. The findings evidence that MI patients with late ventricular potentials and end-diastolic left ventricular index above 100 ml/m2 in subacute period may be considered as a group of high risk in need of individual approach and further therapy. The discovered lowering of informative value of non-invasive methods in patients late after MI dictates the necessity of new approaches to detection of electrophysiological disturbances and sudden death risk in registration of postinfarction dilatation of the heart.     

Fertilization in vitro. A review over the medical indications and suggestion to unified guidelines for public fertility clinics in Denmark

Medical indications for in vitro fertilization and embryo transfer (IVF-ET) internationally and in Denmark are reviewed. Reports from large international centres document that tubal infertility, unexplained infertility, endometriosis and male infertility are equally good indications for IVF. Traditionally, tubal infertility has been the only medical indication qualifying for IVF treatment within the National Health Service in Denmark. Thus, in this country, couples with unexplained and male infertility and with endometriosis have to pay up to 25,000 D.Kr. per IVF-ET treatment in private fertility clinics. Since there is no scientific basis for this discrimination, it is urged that the present rules are changed, so that couples with unexplained and male infertility and endometriosis are also allowed IVF treatment free of charge in the public fertility clinics.     

网格曲面中孔洞的光滑填充算法研究

三角网格模型是几何描述的一种重要形式，有着广泛的应用。但三角网络模型常常会存在孔洞缺陷。这些孔洞的存在一方面影响视觉效果，另一方面会影响许多后续的操作，如快速原型制造、有限元分析等，因此有必要对这些孔洞进行修补。目前绝大多数孔洞填充算法是将网格模型中的孔洞提取成空间多边形，并对孔洞多边形进行三角化。这种处理方法的主要缺陷是没有考虑网格曲面在孔洞附近的几何形态，因而填充部分不能与整个曲面光滑地融为一体。笔者提出了一种三角网格曲面中孔洞的光滑填充算法。该算法根据孔洞周围网格曲面的几何信息来增加孔洞内部的采样点，然后再对增加的采样点进行三角化，较好地解决了填充部分与整体曲面光滑连接的问题。