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661.
以浸渍法制备的10%V/Al2O3为催化剂,研究对GB染毒空气的脱除效果,考察接触时间、温度、温度和浓度等因素对GB染毒空气脱除效果的影响,用GC-MS和LC-MS对尾气组分进行了检测分析. 相似文献
662.
军事素质基础综合训练的改革与实践研究 总被引:1,自引:0,他引:1
以提高军事素质为核心,结合“4+1”培养模式对复合型军事人才的要求,对军事素质基础综合训练教学进行了改革。重点阐述了深化军事素质基础综合训练的教学改革特点和实践效果,为总装备部乃至全军院校进一步深化军事基础教学改革提供一些思路和参考。 相似文献
663.
This article is devoted to the study of an M/G/1 queue with a particular vacation discipline. The server is due to take a vacation as soon as it has served exactly N customers since the end of the previous vacation. N may be either a constant or a random variable. If the system becomes empty before the server has served N customers, then it stays idle until the next customer arrival. Such a vacation discipline arises, for example, in production systems and in order picking in warehouses. We determine the joint transform of the length of a visit period and the number of customers in the system at the end of that period. We also derive the generating function of the number of customers at a random instant, and the Laplace–Stieltjes transform of the delay of a customer. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 646–658, 2015 相似文献
664.
The Riffian rebel leader Mohammed Abd el-Krim Al-Khattabi (1882–1963) became an important early guerrilla leader by successfully initiating extensively organized resistance in the Moroccan Rif against Spanish and French imperial power in the early 1920s. The Rif War triggered a wave of adventure films since the 1930s. This article will look at some of these, especially Sergeant Klems (1971) and The Wind and the Lion (1975), and suggest that they can be seen in terms of the wider impact of screen Orientalism derived from the iconic film Lawrence of Arabia (1962) directed by David Lean. The article will show that these films promoted what it terms a colonial gaze by underlining many stereotyped cinematic clichés relating to the Islamic cultural area and Abd el-Krim's revolt that stretch back to the early history of cinema. 相似文献
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《防务技术》2022,18(10):1914-1921
The monolithic foamed propellants with high densities were prepared by casting and two-step foaming processes. Glycidyl azide polymer (GAP) and isocyanate were used as the binder system and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW, CL-20) was employed as the energetic component. The newly designed formulation containing 60 % CL-20 produced a force constant of 1077 J/g and low flame temperature of 2817 K. Two foamed propellants with densities of 1.32 g/cm3 and 1.53 g/cm3 were fabricated by a confined foaming process and examined by closed bomb tests. The results revealed that porosity significantly affects burning performance. A size effect on combustion behaviors was observed for the foamed propellant with 5.56 % porosity, and a double-hump progressive dynamic vivacity curve was obtained. At last, the 30 mm gun test was carried out to demonstrate the interior ballistic performance, and the muzzle velocity increased by 120 m/s at the same maximum chamber pressure when monolithic propellant was added in the charge. 相似文献
668.
In a multifunction radar, the maximum number of targets that can be managed or tracked is an important performance measure. Interleaving algorithms developed to operate radars exploit the dead‐times between the transmitted and the received pulses to allocate new tracking tasks that might involve transmitting or receiving pulses, thus increasing the capacity of the system. The problem of interleaving N targets involves a search among N! possibilities, and suboptimal solutions are usually employed to satisfy the real‐time constraints of the radar system. In this paper, we present new tight 0–1 integer programming models for the radar pulse interleaving problem and develop effective solution methods based on Lagrangian relaxation techniques. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004. 相似文献
669.
基于BP人工神经网络的GPS/SINS组合导航算法 总被引:1,自引:0,他引:1
基于扩展Kalman滤波的GPS/SINS组合导航算法,需要对原始的非线性连续系统模型进行线性化和离散化处理,要求系统噪声和测量噪声为零均值的高斯白噪声,且易于出现滤波器发散。BP人工神经网络无需对所求解的问题建模,能够很好地逼近系统非线性特性,获得较高精度的导航定位信息;还具有计算过程稳定,不涉及矩阵求逆,不需要迭代逼近,以及容易实现并行处理等优点。设计适用于GPS/SINS组合导航系统的BP网络模型,并在标准的BP算法基础上,采用共轭梯度法改进网络训练速度及精度。最后,通过仿真算例说明BP网络方法用于GPS/SINS组合导航计算的可行性。 相似文献
670.
分析了一种ZCS半桥式DC DC变流器时域工作特性.通过研究其工作各阶段的特性建立了其状态空间模型,采用Matlab语言进行编程仿真,得到其输出电压时域仿真波,与实测吻合,证明了所建状态空间模型的正确性,得到变流器工作的一些有用结论,有助于指导下一步变流器的传导干扰分析和抑制. 相似文献