火控雷达抗自卫干扰研究

机载自卫干扰设备,体积小便于灵活机动,干扰方式多种多样,对火控雷达的探测、跟踪和生存能力造成了很大的威胁。介绍了当前机栽自卫干扰设备的基本功能和主要组成,回顾了其发展历程,分析了抗自卫干扰的必要性和可行的现实条件。在此基础上,从目前抗干扰技术和实例中,总结并提出了抗击敌自卫干扰的主要对策。     

高密度电阻率法对盐渍土的检测效果分析

在天然状态下,盐渍土为较好的地基,一旦因自然条件的改变就会产生严重的溶陷、膨胀和腐蚀,使建筑物裂缝、倾斜或结构被腐蚀破坏.本文主要从高密度电阻率法和地质雷达法的探测精度问题展开讨论,通过对瓜州干河口风电场盐渍土所进行的高密度电阻率法和地质雷达法无损检测数据的分析和对比,表明高密度电阻率法对盐渍土的检测效果较地质雷达法更...     

短时大暴雨的多普勒雷达探测及暴雨预警信号发布

本文通过对环流背景和广州CINRAD-SA多普勒天气雷达资料的详细分析,探讨了发生在广州市的一次短时大暴雨的成因.结果表明：广州市夏季短时大暴雨在低空急流、低层辐合以及高空辐散和抽吸作用的有利环流背景下,多个单体接连穿越同一地区所造成,单体排列方向与单体移动方向一致.弱中气旋特征、逆风区和能量锋对对流的维持和加强起到了十分重要的作用.另外本文还对暴雨预警信号的发布技巧进行了探讨.     

隧道含水断层破碎带的探测

以泉三高速公路某隧道含水断层为例,对比瑞利波和地质雷达两种探测技术,论述其优缺点,阐明瑞利波探测技术探测公路施工隧道含水断层破碎带的优点。     

RASTER-BASED HYDROLOGIC MODELING OF SPATIALLY-VARIED SURFACE RUNOFF1

ABSTRACT: The proliferation of watershed databases in raster Geographic Information System (GIS) format and the availability of radar-estimated rainfall data foster rapid developments in raster-based surface runoff simulations. The two-dimensional physically-based rainfall-runoff model CASC2D simulates spatially-varied surface runoff while fully utilizing raster GIS and radar-rainfall data. The model uses the Green and Ampt infiltration method, and the diffusive wave formulation for overland and channel flow routing enables overbank flow storage and routing. CASC2D offers unique color capabilities to display the spatio-temporal variability of rainfall, cumulative infiltrated depth, and surface water depth as thunderstorms unfold. The model has been calibrated and independently verified to provide accurate simulations of catchment response to moving rainstorms on watersheds with spatially-varied infiltration. The model can accurately simulate surface runoff from flashfloods caused by intense thunderstorms moving across partial areas of a watershed.     

Degradation of a Terephthalate-containing Polyester by a Thermophilic Microbial Consortium

Biomax^® is an aliphatic-aromatic polyester. The biodegradability of Biomax^® was studied at 58 °C using a laboratory scale bioreactor. The bioreactor was inoculated with bacteria derived from compost and supplemented with powdered Biomax^® and an additional energy source. After a period of acclimation, the microorganisms in the bioreactor were capable of metabolizing the major components of the polymer, i.e., TPA and ethylene glycol. TPA and ethylene glycol were detected in the bioreactor only when they were added. Degradation and disintegration of the powdered Biomax^® was monitored by laser diffraction. The particle size distribution of the powdered polymer progressively shifted toward smaller sizes until the diameters of the polymer particles were indistinguishable from bacteria. The types of microbes in the bioreactor were determined by analyzing 16S rRNA gene sequences. The bacteria belonged to 35 different groups, and the majority of the bacteria appeared to represent new species.     

"艾利"台风异常路径与登陆地点分析

2004年18号台风“艾利”的移动路径在登陆前发生了两次左折，是一次十分罕见的异常路径。从大尺度环流、天气尺度特征分析发现，双台风作用使两个台风产生逆时针旋转效应，及由东西环副高联成的东西向高压坝的阻挡作用，台风西北侧我国江南一福建的偏东一东北气流的加强和沿海地形摩擦效应的综合效果是造成台风“艾利”异常路径的原因。“艾利”台风第二次左折向西南方向移动，沿着福建海岸线的移动阶段，利用沿海多部雷达的高时空分辨率的定位，准确及时地反映了台风西折的动向，为防台抗灾提供了重要的信息，从一定程度上弥补了第二次左折路径预报存在一定偏差的不足。分析还发现，“艾利”台风在第二次左折前后，多普勒雷达速度图象上出现了明显的风速极值区不对称特征，西北象限风速极值大于其它象限的不对称分布可能是导致并维持AERE台风向西南方向移动的重要原因。最后，利用沿海地区稠密的自动气象站探测到的风和气压资料，较好地验证了雷达定位的准确性，同时能够更精确地判定台风的登陆点。     

激光片光前向散射法测量烟雾颗粒尺寸分布

提出了一种利用激光片光CCD成像测量火灾烟雾颗粒粒径的方法，结合Mie散射理论确定了采取前向散射成像的方法测量烟雾颗粒尺寸分布，针对摄影测量过程中的成像形变，给出了结合数字摄影测量DLT技术进行数字校正的方法，并对实验方法和结果进行了分析与讨论。     

Modeling and simulation of arc: Laser and hybrid welding process

Welding is a fabrication process to join two different materials. Among the many welding processes, the arc and laser welding processes are the most widely used. Great effort is required to understand the physical phenomena of arc and laser welding due to the complex behaviors which include liquid phase, solid phase and, gas phase. So it is necessary to conduct numerical simulation to understand the detailed procedures of welding. This paper will present the various numerical simulation methods of the arc welding processes such as arc plasma, gas tungsten arc welding, gas metal arc welding, laser welding, and laser–arc hybrid welding. These simulations are conducted by the finite element method, finite differential method and volume of fluid method to describe and analyze the various welding processes.     

军用地面雷达装备环境工程探讨

目的提高军用地面雷达装备的环境适应性。方法按GJB 4239的要求,实施雷达装备的环境工程。简要阐述雷达装备环境工程的各项工作内容和实施方法,分析雷达寿命期内经历的环境和雷达定型阶段的环境鉴定试验方法。结果提出了目前存在的问题并给出了改进建议。结论按GJB4239的要求实施装备环境工程的各项工作,可使军用地面雷达获得良好的环境适应性。