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681.
When considering the bomb explosion damage effect, the air shock wave and high-speed fragments of the bomb case are two major threats. In experiments, the air shock wave was studied by the bare ex-plosives superseding the real cased bomb; in contrast, the bomb case influence was ignored to reduce risk. The air explosion simulations of the MK84 warhead with and without the case were conducted. The numerical simulation results showed that the bomb case significantly influenced the shock wave generated by the bomb: the spatial distribution of shock wave in the near field changed, and the peak value of shock wave was reduced. Breakage of the case and kinetic energy of the fragmentation consumed 3 and 38% of the explosion energy, respectively. The increasing factors of the peak over-pressure induced by the bare explosive on the ground and in the air were 1.43-3.04 and 1.37-1.57, respectively. Four typical stages of case breakage were defined. The mass distribution of the fragments follows the Mott distribution. The initial velocity distribution of the fragments agreed well with the Gurney equation. 相似文献
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We study the problem of recovering a production plan after a disruption, where the disruption may be caused by incidents such as power failure, market change, machine breakdown, supply shortage, worker no‐show, and others. The new recovery plan we seek after has to not only suit the changed environment brought about by the disruption, but also be close to the initial plan so as not to cause too much customer unsatisfaction or inconvenience for current‐stage and downstream operations. For the general‐cost case, we propose a dynamic programming method for the problem. For the convex‐cost case, a general problem which involves both cost and demand disruptions can be solved by considering the cost disruption first and then the demand disruption. We find that a pure demand disruption is easy to handle; and for a pure cost disruption, we propose a greedy method which is provably efficient. Our computational studies also reveal insights that will be helpful to managing disruptions in production planning. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献
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We focus on the concave‐cost version of a production planning problem where a manufacturer can meet demand by either producing new items or by remanufacturing used items. Unprocessed used items are disposed. We show the NP‐hardness of the problem even when all the costs are stationary. Utilizing the special structure of the extreme‐point optimal solutions for the minimum concave‐cost problem with a network flow type feasible region, we develop a polynomial‐time heuristic for the problem. Our computational study indicates that the heuristic is a very efficient way to solve the problem as far as solution speed and quality are concerned. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005 相似文献
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论红军时期的士兵委员会 总被引:1,自引:0,他引:1
军人委员会是人民军队在长期革命和建设实践中组建、演变并保留下来的群众性组织,前身是红军时期的士兵委员会。本文着力探讨士兵会的创建方式、促成因素、组织形式及作用、性质和历史意义。考察红军时期的士兵会,既是追溯我军军人委员会这一基层群众性组织和军内民主载体的前期形态,亦是对新时期发扬军队民主优良传统的一种求证与反思。 相似文献
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中国历史上军事科技与军事理论的命运是休戚与共,一荣俱荣,一损俱损的,往往是军事科技荣损于前、军事理论伴随其后。这是因为,军事科技是军事理论发展的基础和前提,其对军事理论的发展必然产生由低向高、由点向面的影响。有些军事理论虽具有古今相通的特征,但其内容及应用方法必须随着军事技术的发展而发展。同时,先进的军事理论对军事科技的发展具有牵引和拉动的功能,军事科技只有在正确的军事理论指导下才能不断得到发展。只重科技、轻视理论,与只重理论、轻视科技一样,对二者的发展都是有害的。 相似文献
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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
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