Link4A数据链压制干扰效果分析

首先介绍了Link4A数据链信号的特征,建立了各种干扰样式模型,并在非相干检测前提下分析了各种干扰样式的理论误码率,仿真了各种干扰样式对Link4A数据链的干扰效能;其次,分析了数据链信号和干扰信号的传播损耗,计算了不同通信距离和干扰距离时通信接收机端的干信比,并得出最优干扰样式选择原则.     

EDITOR'S NOTE

The Nonproliferation Review (NPR) recently interviewed Ambassador Sergio de Queiroz Duarte of Brazil, who presided over the 2005 Seventh Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). Ambassador Duarte discussed his views on the outcome of the conference and the future of the treaty. He provided NPR with valuable insights into the outcome of the conference and also shared his thoughts on some of the most pressing issues confronting the NPT today, including the Middle East, nuclear terrorism, elimination of the threat of highly enriched uranium in the civilian nuclear sector, proposals to limit access to the nuclear fuel cycle, nuclear disarmament, and negative security assurances. Blaming the failed conference on a general lack of political commitment among states parties and their unwillingness to negotiate common solutions, Ambassador Duarte stressed that “the conference should face squarely its own failure without my attempting to disguise or sugarcoat the deep differences of view, which must be resolved with courage and determination by the states parties if they want the treaty to remain effective.”?He emphasized that if states fail to act on their overriding interest in upholding the NPT, especially if states parties continue to ignore or disregard their nonproliferation and nuclear disarmament obligations, some states might come to believe that their security interests are no longer served by the treaty. The future prospects of the NPT would then “look dire indeed.”     

THE GEOGRAPHY OF NUCLEAR PROLIFERATION NETWORKS

This article uses a geographic approach to examine one aspect of the nuclear black market: the coordinators who bring buyers and sellers together, and transport goods between them. The most important factor in determining the geographical structure of a proliferation network is the network coordinator's access (or lack thereof) to unique state resources. Coordinators with access to state resources and prerogatives can avoid embedding themselves in hostile countries or relying on commercial infrastructure, often leading to territorially diffuse logistical networks. Coordinators without such access are forced to rely on commercial infrastructure and favorable local political, economic, and social conditions, often resulting in territorially centralized logistical networks. This is illustrated through case studies of Abdul Qadeer Khan's supply networks to Pakistan, Libya, and Iran. The article concludes with some observations about the implications of a geographical approach for understanding nuclear proliferation networks.     

基于龙芯1A+BMN2200S的加固手持终端设计与实现

结合国产化工程实践需要介绍了一款新型的基于龙芯1A+BMN2200S的GPS/北斗加固手持终端设计思路与方法,该手持终端主要应用于单兵指挥系统。详述了手持终端系统的硬件设计,国产麒麟linux操作系统内核的移植,BMN2200S模块的原理,GPS和北斗信息的实时解算。该系统经实验证明能满足军用系统的高安全性和可靠性,并且有良好的实时性和实用性的特点。     

任务空间概念模型VV&A研究

任务空间概念模型是现实世界军事知识的第一层抽象,是仿真系统开发的业务基础。所以任务空间概念模型的质量直接影响到仿真系统的质量,任务空间概念模型自身的VV&A是一个非常值得关注的问题。任务空间概念建模本质上看是军事领域的知识表示或者需求描述,定性描述占主要,定量成分非常少。因此,传统的通过分析输出数据的方法不能适应任务空间概念模型的特点。概要介绍了任务空间概念模型建模,并且提出了从专家法、静态校核机制、概念执行机制三个角度来考察模型质量的思路。     

窄带干扰下GPS接收机捕获性能的研究

针对GPS接收机抗干扰能力强的特点,分析了窄带干扰对接收机的捕获性能的影响.在扩频理论的基础上,给出了GPS C/A码接收机信号捕获的数学模型,计算得出平均捕获时间与捕获时间方差,给出窄带干扰下的接收机信号捕获的仿真结果.结果表明,当窄带干扰功率超过一定的值时,会导致GPS接收机捕获性能的严重恶化.     

全数字交流异步电机伺服系统的设计与实现

介绍了基于TMS320LF2407A的交流伺服系统的硬件和软件构成及实现方案,给出了系统的实验结果,矢量控制与其它控制方法的比较结果表明,与其它控制方式相比,转差频率矢量控制具有动态性能好、控制精度高的突出优点,适合于伺服系统的设计.     

改进型Voronoi图和动态权值A*算法的无人机航迹规划

针对实际作战环境中的不同威胁等级和不同威胁实体的威胁源,提出了改进型的Voronoi图,并建立了基于改进型Voronoi图的航迹规划空间;基于A*算法的估价函数在不同阶段对指标的敏感度不同,在传统的启发式A*搜索算法基础上提出了动态权值A*搜索算法,提高了航迹搜索的效率,实现了航迹搜索过程快速性和准确性的结合。最后通过Matlab仿真计算出由动态权值A*算法得到的最优航迹,并进行了航迹的平滑处理,仿真表明了该方法的可行性。     

回归再时效7A60铝合金在0.5mol/L NaCl溶液中的点蚀性能

采用腐蚀电化学的点蚀极化曲线并结合腐蚀形貌的扫描电镜分析的方法,研究了回归再时效(RRA)工艺处理7A60铝合金在0.5mol/L NaCl溶液中的点蚀行为,对其耐点蚀性能进行了评价,并探讨了RRA工艺改善该合金点蚀性能的机理。结果表明:采用120RRA工艺(120℃×24h预时效+195℃×0.5h回归+120℃×24h再时效)处理后,7A60铝合金在0.5mol/L NaCl溶液中的阳极极化曲线闭合环面积减小,再钝化电流密度Ipp降低,蚀孔较浅,RRA工艺在一定程度上改善了该铝合金在0.5mol/L NaCl溶液中的耐点蚀性能。     

损伤铝合金表面超声焊接界面断口分析与结合机理

采用超声焊接铝合金箔材的工艺修复处理表面腐蚀受损的2A12CZ基体,并利用Quanta200型环境扫描电子显微镜分析了截面形貌及箔材与基体之间界面表面断口的微观形貌。结果表明：从截面来看,箔材与基体之间大部分发生了焊合,界面分界线大部分消失;从机械脱开的界面断口来看,其表面微观形貌表现为鳞片状及韧窝状的典型金属型断口形貌。这说明在给定条件下,焊接部位大部分呈冶金结合。最后对铝台金箔材与铝合金基体之间超声焊接机理进行了探讨。