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701.
分析了动力装置水位测量系统的现状 ,并通过实验测试认为改进型水位测量仪表系统的设计是可行的 ,与原来的系统相比具有性能稳定的特点 .最后 ,提出了减少水位测量系统误差的方法和提高测量系统性能的建议 .  相似文献   
702.
结合前人在海浪功率谱以及海浪产生磁场两方面的研究 ,求出了海浪 磁场系统的传递函数 ,分析了该系统的性质 ,并利用该传递函数和Neumann谱、PM谱计算了磁场功率谱 ;在此基础上 ,根据实际观测我国海区的海浪高度 周期分布 ,求解海浪分布参数 ,模拟实际的海浪过程 ,求出了实际情况下的海浪感应磁场功率谱 ,并分析了其特性 .  相似文献   
703.
从核电站压水堆动力装置在运行中ΔT超温度 /超功率保护功能出发 ,介绍了压水堆ΔT超温度 /超功率保护系统 ,分析了确定极限限制线以及保护区的方法 ,并对此作出了评价 .  相似文献   
704.
电力电子技术的现状与绿色变换的发展趋势   总被引:3,自引:0,他引:3  
论述了电力电子技术的发展及其产生的影响 ,认为绿色变换是消除谐波污染、进一步发展绿色化电力电子技术的唯一途径 ,由此阐明了绿色变换技术的现实意义  相似文献   
705.
结合舰船电力网络绝缘监测装置进行支路电阻测量与故障支路判断时的需要 ,设计了采集漏电流信号的大口径弱电流传感器 ,并给出了试验数据 .设计出的传感器已用于实际装置 ,试验运行状况良好  相似文献   
706.
《防务技术》2020,16(4):883-892
The influence of initiation modes on the explosive dispersion process of the multi-layer composite charge (MCC) was studied. Overpressure sensors and high-speed photography system were used to investigate the energy release process of an MCC with a specific structure. The shock wave pressure and explosive dispersion characteristics of the MCC under different initiation modes were compared. The forming and expanding process of the shock wave of the composite charge under different initiation modes was determined. The separation position of the shock wave and fireball interface was determined. The calculation formulas of the shock radius and overpressure of the composite charge are presented. The radius of the shock wave of the composite charge was significantly affected by the initiation mode. Moreover, the development process of the composite explosive fireball under different initiation modes was analyzed, the variation rules of the composite charge dispersion radius and fireball dispersion velocity with time were obtained under the different initiation modes, the explosion energy release rate of composite charge under simultaneous initiation modes was the highest, and the peak overpressure under the simultaneous initiation mode was 1.61 times that of central single-point initiation.  相似文献   
707.
《防务技术》2020,16(2):290-298
In order to give the energy output structure of typical explosives near-ground explosion in real ground conditions, the free-field shockwave, ground reflection shockwave and Mach wave overpressure time history of composition B explosive, RDX explosive and aluminized explosive were measured by air pressure sensors and ground pressure sensors. The shape of the free-field shock wave, ground reflection shock wave, and Mach wave and explosion flame were captured by high-speed camera. The experimental results show that, at the same horizontal distance from the initiation point, the peak overpressure of explosive shock wave of composition B explosive, both in the air and on the ground, is less than that of RDX and aluminized explosives. At a distance of 3.0 m from the initiation point, the peak overpressure of aluminized explosives is slightly less than that of RDX explosives. Owing to the exothermic effect of aluminum powder, the pressure drop of aluminized explosives is slower than that of RDX explosives. At 5.0 m from the initiation point, the peak overpressure of aluminized explosives is larger than that of RDX explosives. At the same position from the initiation point, among the three kinds of explosives, the impulse of aluminized explosives is the maximum and the impulse of composition B explosives is the minimum. With the increase of the horizontal distance from the initiation point, the height of Mach triple-points (Mach steam) of the three explosives increases gradually. At the same horizontal distance from the initiation point, there is poorly difference in the height of Mach triple-points between aluminized explosive and RDX explosive, and the height of Mach triple-points of composition B explosive is much smaller than that of other two explosives. The maximum diameter and duration of the fireball formed by aluminized explosives are the largest, followed by composition B explosive, and the maximum diameter and duration of the fireball formed by RDX explosive are the smallest.  相似文献   
708.
通过建立等离子体中的波动方程、电子传递方程和重物质传递方程,研究了等离子体对高功率微波传输特性的影响。研究了高功率微波与等离子体相互作用中产生的电子密度和透射电场的变化过程,并重点分析了变化过程中入射波频率产生的影响。研究结果表明,在相互作用过程中,等离子体中的电子密度和透射电场在一定条件下会发生阶跃变化,即等离子体区域平均电子数密度会在极短的时间内由1×10~9m~(-3)增加到1×10~(19)m~(-3),平均电场强度也会由初始场强跃变为零,并且这种变化的产生存在一定的入射阈值场强和最低产生时间。当入射电磁波的频率不同时,产生阶跃变化所需的场强阈值和最低产生时间就会变得不同,高功率微波与等离子体相互作用中存在一定的色散效应。在所考虑的范围内,阈值场强随入射波频率线性增长,而最低产生时间随电磁波频率呈非线性增长变化。  相似文献   
709.
The beginning of the twenty-first century has witnessed the emergence of balancing responses to the US hegemony, among which Russia’s foreign policies stand out as corresponding to what is understood as ‘hard balancing.’ Why is the United States being balanced against? This paper categorizes the existing theories of non-balancing into six conditions that together guarantee the absence of balancing and demonstrates that the current unipolar system can satisfy only one of them. This eases the systemic constraints and makes balancing possible. The paper then presents three cases of balancing with reference to President Putin’s foreign policy. It argues that even though in terms of relative military capabilities unipolarity still holds, the emergence of counter-hegemonic balancing is indicative of important changes in the nature of post-Cold War American domination.  相似文献   
710.
How do we understand combat effectiveness – soldiers’ performance in battle? Despite the broad consensus that understanding combat effectiveness is important both for scholars and policymakers, there is widespread disagreement about what combat effectiveness is. More specifically, studies of effectiveness tend to focus on either the skill of soldiers in battle, or their will to fight. Yet both skill and will are essential components of an effective fighting force. This article argues that understanding combat effectiveness requires understanding both of these key components of effectiveness. In other words, combat effectiveness requires both the skill and will to engage the enemy in an organized manner. It then demonstrates the usefulness of this conceptualization by applying it to the cases of British, Indian, and Australian forces fighting the Japanese during the Second World War. Only when scholars are talking about the same concept will our understanding of the conditions under which militaries are effective in battle progress. By comparing different units fighting the same opponent under the same material conditions, I demonstrate that units vary both in their combat skill and their will to fight, and that understanding their effectiveness in battle requires analyzing both of these key factors.  相似文献   
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