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1.
本文介绍一台200KeV中子发生器的调试结果:用200KeV,1.5mA氘束轰击氚钛靶,由(d,T)反应产生中子产额可达2×10~(11)n/s;有效直径为20mm质量好的新靶,在160Kev,0.8mA下,中子产额5×10~(10)n/s维持4小时。该发生器采用高频离子源,用普通高压电瓷绝缘环装配加连管,高压电源采用四级倍压回路、离子源和高压电源的供电频率50Hz,靶室用水冷却。  相似文献   

2.
我们研制了并行高速 HF-Modem SC-3466,它的最高数据传输率可达2400bit/s,具有多种功能可供用户自由选择,能满足用户对数字话音及一般数据传输的要求。本文详细讨论了本系统中差错控制编码、交错与去交错技术的设计与实现。  相似文献   

3.
针对某总线数据传输网络要求利用光纤实现宽频带通信链路的问题,提出了一种基于高速光纤通信接口的总线网络链路设计,该设计中以现场可编程逻辑门阵列(field programmable gate array,FPGA)为控制芯片,HTA8525和Aurora协议为光纤通信接口的核心实现光电转换,利用以太网模块将数据转化为上位机可识别的数据帧,可验证总线数据传输的准确性。实验和仿真结果表明,总线网络中的光纤通信链路传输速率达到10 Gb/s级,能够快速进行数据传输,并且可以将数据回传至上位机进行观察分析,解决传统总线网络中传输速率受限等问题,同时提升总线网络的可靠性,满足任务要求。  相似文献   

4.
等精度频率测量方法   总被引:6,自引:0,他引:6  
介绍单片机应用系统中的频率测量方法,其特点是在不需要复杂的传统等精度频率测量控制的情况下,利用单片机的自身特性,实现宽范围内实用、简单而且精度较高的等精度频率测量.其测量分辨率可达到1×10-6/s.  相似文献   

5.
论述了静风洞概念并设计和建立了一座小型静风洞SQWT-120。SQWT-120的设计马赫数为4.0,喷管出口直径为120mm,Re=0.46~1.78×107,运行时间为6~60s。测量结果表明,喷管出口马赫数为3.8,在x从160~438mm一段轴向距离内,ΔM/-M≯±1.2%。在P0=0.4MPa,喷管出口6cm处,静压脉动值不超出0.1%,风洞工作时间15s,具备静风洞试验能力。  相似文献   

6.
在实时控制系统中,乘除法指令用的较多。DJS—130机无专门的乘除法指令,用子程序做乘、除法,每次需时150μS以上,即乘、除法运算速度每秒6700次。虽然加、减法运算速度可达每秒50万次,但平均速度并不高。若乘、除法指令占30%,平均执行一条指令的时间为:150×0.3+2×0.7=46.4μS即,速度只有1/(46.4×10~(-6))≈2万次/秒。 622机增加了专门的乘除法指令,每次乘、除法时间为18μS,平均执行一条指令的时  相似文献   

7.
为快速、准确地测定出现场舰船火灾烟气中氯的含量,在体系中加入适量的十二烷基苯磺酸钠(DBS)、聚乙烯醇溶液(PVA)和吐温-80,对传统AgCl浊度法进行了改进。结果表明,系统的稳定性、灵敏度均大幅度提高,检测限则由3.5×10-1mg/l降低至3.1×10-2mg/l。改进后的方法线性范围宽、重现性好。  相似文献   

8.
性能数据系统发射率 2×800发/分初速 1400米/秒俯仰范围 -13°~+80°旋回范围无限高低瞄准速度 75°/秒高低瞄准加速度 100°/秒~2方向瞄准速度 120°/秒  相似文献   

9.
本文研究了NICALON SiC束丝纤维增强铝预制丝在15~400℃温度区间内的热膨胀特性。研究表明预制丝两次热循环后得到的膨胀曲线不一致,该曲线在15~400℃范围的平均热膨胀系数分别为3.2×10~(-6)℃~(-1)、4.1×10~(-6)℃~(-1)。本文对预制丝的热膨胀行为进行了理论分析和探讨,计算值和实验值较为符合。  相似文献   

10.
航空发动机可以对空气增压,并且增加气流温度,理论上存在应用于超声速引射系统的可能。分析了气源对引射器性能的影响以及引气对航空发动机的影响,介绍了3种航空发动机在超声速引射系统中可能的布局方案。针对某领域内的排气参数要求,分别对3种布局方案进行了计算分析。计算结果表明,当上游气体压强为0.044×105 Pa和0.029 3×105 Pa时,通过合理选择发动机的布局以及工作参数,发动机可以直接将上游气体排出或者作为驱动气源应用于超声速引射系统。  相似文献   

11.
Recent events demonstrate the complex and adaptive approach employed by Russia to reassert influence in Europe. The changing face of Russia’s strategy commenced in 2007 when it launched a crippling cyber-attack against Estonia. This was followed by a large Russian conventional attack against Georgia in 2008, occupying two large areas of the nation. 2014 witnessed the Russian annexation of Crimea where in just a week, Russia seized control of Crimea “without firing a shot.” The annexation of Crimea was rapidly followed by a Russian inspired and led subversive war in eastern Ukraine. The common thread among these diverse Russian operations is its use of ambiguity to confound and confuse decision makers in the West.  相似文献   

12.
The Indian Army, a force trained primarily for conventional warfare, has been engaged in internal counter-insurgency operations since the 1950s. Despite such a long innings on a counter-insurgency mode, little attention has been accorded within military circles to doctrinal innovation for waging sub-conventional warfare in India's democratic political context. At best, the Army continues to view counter-insurgency duty as secondary to its primary duty of defending India from external conventional threats. By conceptualizing a counter-insurgency strategy of ‘trust and nurture’, this article aims to fill this critical doctrinal gap in India's military policy. The author argues that a counter-insurgency strategy of ‘trust and nurture’ based on democratic political culture, measured military methods, special counter-insurgency forces, local social and cultural awareness and an integrative nation-building approach will result in positive handling of India's internal security problems. The author utilizes India's counter-insurgency experiences in Assam, Mizoram, Nagaland, Punjab, and Operation ‘Sadhbhavana’ in Jammu and Kashmir as illustrative empirical indicants in order to validate the ‘trust and nurture’ strategy.  相似文献   

13.
The war that Portugal was obliged to fight in Africa began in 1961 and immediately stretched the resources of its armed forces. Nowhere was this thinness more apparent than in policing the vast territory of Angola. The east and southeast of Angola were particularly vulnerable, as the area was a vast, sparsely populated region characterised by enormous featureless plains or chanas covered in tall grass and broken by an extensive river system and mountainous forests. The only military solution to policing these immense spaces was aviation and specifically the helicopter that could carry troops into battle, protect them with a gunship and bring them home when the operation was concluded. The immediate problem for the Portuguese Air Force (Força Aérea Portuguesa or FAP) in Angola and elsewhere was a scarcity of helicopters. The solution was an alliance with South Africa, which had a strong inventory of Alouette IIIs, to help in policing the east. This move was likewise in the interest of South Africa, as its threat came from Zambia through south-eastern Angola. This article examines the strategic and tactical development of this unusual, cross-cultural alliance and the symbiotic relationship that resulted in destruction of the enemies of both in Angola.  相似文献   

14.
In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.  相似文献   

15.
Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).  相似文献   

16.
本文主要介绍了国外焊条的现状和发展趋势,包括焊条的高韧性、高效率、低尘低毒和耐吸潮性能,为国内的焊条研究提供了参考依据。  相似文献   

17.
《Arms and Armour》2013,10(2):122-143
Many late medieval documents, notably inventories of arms and armour, of Englishmen contain references to ‘Scottish swords’ and other weapons. What did the compilers of these documents mean when they described a weapon as ‘Scottish’? How did such weapons come to be in the possession of these men? This article will attempt to explain this phenomenon drawing on primary documentary sources and surviving material culture from Glasgow Museums’ collections and others, as well as artworks from the period.  相似文献   

18.
This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.  相似文献   

19.
The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.  相似文献   

20.
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