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101.
《防务技术》2014,10(2):101-105
Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN) (TEGDN propellants) to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper. 相似文献
102.
由于SiC光学材料具有高化学稳定性,使其在普通的等离子体加工中难以获得较高的加工效率。在等离子体加工实验中,我们发现提高等离子体的自身射频电压,可增强等离子体与SiC材料之间的电弧放电作用,而借助电弧的增强作用提高SiC材料的加工效率,因此本文提出了电弧增强等离子体加工方法。为研究电弧的形成原理,本文使用自制的探针分别测量了普通电感耦合等离子体和电弧增强等离子体的电压。并分别使用传统方法和电弧增强方法对S-SiC进行直线扫描加工实验,证明了电弧增强等离子加工方法在加工过程中具有更高的加工效率。 相似文献
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介绍了双DSP技术在无线分组网络路由控制器中的应用,阐述了双DSP间通信方案的选择及双DSP系统的实现,提出了一种双DSP对多个串行通信控制器(SCC)的设计方案,并给出了具体的硬件、软件设计方法. 相似文献
105.
BTT控制系统半实物仿真试验以BTT试验器为背景,配合BTT控制技术研究可全面验证导弹控制系统设计。给出了半实物仿真试验方案、方法及试验结果分析,试验结果表明BTT控制系统设计满足最小侧滑(近似零侧滑角)倾斜转弯的技术指标要求,半实物仿真试验方法正确。 相似文献
106.
Fangruo Chen 《海军后勤学研究》2000,47(5):422-439
Consider a distribution system with a central warehouse and multiple retailers. Customer demand arrives at each of the retailers continuously at a constant rate. The retailers replenish their inventories from the warehouse which in turn orders from an outside supplier with unlimited stock. There are economies of scale in replenishing the inventories at both the warehouse and the retail level. Stockouts at the retailers are backlogged. The system incurs holding and backorder costs. The objective is to minimize the long‐run average total cost in the system. This paper studies the cost effectiveness of (R, Q) policies in the above system. Under an (R, Q) policy, each facility orders a fixed quantity Q from its supplier every time its inventory position reaches a reorder point R. It is shown that (R, Q) policies are at least 76% effective. Numerical examples are provided to further illustrate the cost effectiveness of (R, Q) policies. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 422–439, 2000 相似文献
107.
In this paper, two different kinds of (N, T)‐policies for an M/M/m queueing system are studied. The system operates only intermittently and is shut down when no customers are present any more. A fixed setup cost of K > 0 is incurred each time the system is reopened. Also, a holding cost of h > 0 per unit time is incurred for each customer present. The two (N, T)‐policies studied for this queueing system with cost structures are as follows: (1) The system is reactivated as soon as N customers are present or the waiting time of the leading customer reaches a predefined time T, and (2) the system is reactivated as soon as N customers are present or the time units after the end of the last busy period reaches a predefined time T. The equations satisfied by the optimal policy (N*, T*) for minimizing the long‐run average cost per unit time in both cases are obtained. Particularly, we obtain the explicit optimal joint policy (N*, T*) and optimal objective value for the case of a single server, the explicit optimal policy N* and optimal objective value for the case of multiple servers when only predefined customers number N is measured, and the explicit optimal policy T* and optimal objective value for the case of multiple servers when only predefined time units T is measured, respectively. These results partly extend (1) the classic N or T policy to a more practical (N, T)‐policy and (2) the conclusions obtained for single server system to a system consisting of m (m ≥ 1) servers. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 240–258, 2000 相似文献
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110.
分布孔径红外系统的研究现状及其展望 总被引:1,自引:0,他引:1
介绍了分布孔径红外系统 ( DAIRS)的基本概念与研制现状 ,讨论了DAIRS在先进战斗机及其它作战平台上的应用 ,并简略介绍了其中涉及的关键技术 ,对 DAIRS系统将来可能的发展趋势作了预测。 相似文献