首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   504篇
  免费   11篇
  2020年   8篇
  2019年   10篇
  2018年   8篇
  2017年   15篇
  2016年   13篇
  2015年   9篇
  2014年   5篇
  2013年   121篇
  2011年   7篇
  2010年   4篇
  2009年   9篇
  2008年   6篇
  2007年   4篇
  2006年   5篇
  2005年   11篇
  2004年   9篇
  2003年   6篇
  2002年   4篇
  2001年   4篇
  2000年   5篇
  1999年   5篇
  1998年   4篇
  1997年   4篇
  1996年   10篇
  1995年   9篇
  1994年   10篇
  1993年   6篇
  1992年   12篇
  1991年   21篇
  1989年   9篇
  1988年   5篇
  1987年   11篇
  1986年   13篇
  1985年   18篇
  1984年   5篇
  1983年   5篇
  1980年   6篇
  1979年   4篇
  1978年   7篇
  1977年   6篇
  1976年   6篇
  1975年   4篇
  1974年   10篇
  1973年   6篇
  1972年   9篇
  1971年   6篇
  1970年   10篇
  1969年   5篇
  1968年   6篇
  1967年   5篇
排序方式: 共有515条查询结果,搜索用时 31 毫秒
121.
122.
从"2·15"吉林大火所存在的消防安全管理原因入手,着重分析了<消防法>第51条立法之不足,通过法理与实践相结合的方法,提出了有关<消防法>第51条的完善建议,以期为实践提供理论借鉴.  相似文献   
123.
This article introduces a replacement life-test procedure for the exponential failure rate: Failure-free operation of a unit for at least tk consecutive time units is designated a “success”; the acceptance test is passed if and only if the first success is encountered before k unit failures have been recorded. Test plans are presented and the test is compared with the usual time-truncated test and to the truncated sequential probability ratio test. It is shown that this new test has smaller expected test time than the time truncated test when the true failure rate is small relative to the null hypothesized failure rate. Consistency and unbiasedness are proved and methods for making inferences on failure rate are described.  相似文献   
124.
It is sometimes reasonable to assume that the lifetime distribution of an item belongs to a certain parametric family, and that actual parameter values depend upon the testing environment of the item. In the two-parameter Weibull family setting, suppose both the shape and scale parameters are expressible as functions of the testing environment. For various models of functional dependency on environment, maximum likelihood methods are used to estimate characteristics of interest at specified environmental levels. The methodology presented handles exact, censored, and grouped data. A detailed accelerated life testing analysis of stress-rupture data for Kevlar/epoxy composites is given.  相似文献   
125.
The paper proposes an algorithm for the determination of the solution of the activities to be shortened and the amount by which they are to be shortened in order to minimize the total cost of project completion. This cost involves a linear penalty for tardienss of a set of key events and a linear cost of activity compression from its normal duration. The procedure is a generalization of the work of Fulkerson.  相似文献   
126.
The simplex method is interpreted as a labeling procedure for certain classes of multicommodity flow problems in a manner similar to that for single commodity networks. As opposed to general multicommodity algorithms, no explicit matrix inversion is required; all simplex operations are performed graph-theoretically.  相似文献   
127.
Optimal time-sequential fire-support strategies are studied through a two-person zero-sum deterministic differential game with closed-loop (or feedback) strategies. Lanchester-type equations of warfare are used in this work. In addition to the max-min principle, the theory of singular extremals is required to solve this prescribed-duration combat problem. The combat is between two heterogeneous forces, each composed of infantry and a supporting weapon system (artillery). In contrast to previous work reported in the literature, the attrition structure of the problem at hand leads to force-level-dependent optimal fire-support strategies with the attacker's optimal fire-support strategy requiring him to sometimes split his artillery fire between enemy infantry and artillery (counterbattery fire). A solution phenomnon not previously encountered in Lanchester-type differential games is that the adjoint variables may be discontinuous across a manifold of discontinuity for both players' strategies. This makes the synthesis of optimal strategies particularly difficult. Numerical examples are given.  相似文献   
128.
We consider a class of asymmetric two-person games played on graphs, and characterize all the positions in the game.  相似文献   
129.
This paper develops a mathematical theory for predicting force annihilation from initial conditions without explicitly computing force-level trajectories for deterministic Lanchester-type “square-law” áttrition equations for combat between two homogeneous forces with temporal variations in fire effectivenesses (as expressed by the Lanchester attrition-rate coefficients). It introduces a canonical auxiliary parity-condition problem for the determination of a single parity-condition parameter (“the enemy force equivalent of a friendly force of unit strength”) and new exponential-like general Lanchester functions. Prediction of force annihilation within a fixed finite time would involve the use of tabulations of the quotient of two Lanchester functions. These force-annihilation results provide further information on the mathematical properties of hyperbolic-like general Lanchester functions: in particular, the parity-condition parameter is related to the range of the quotient of two such hyperbolic-like general Lanchester functions. Different parity-condition parameter results and different new exponential-like general Lanchester functions arise from different mathematical forms for the attrition-rate coefficients. This theory is applied to general power attrition-rate coefficients: exact force-annihilation results are obtained when the so-called offset parameter is equal to zero; while upper and lower bounds for the parity-condition parameter are obtained when the offset parameter is positive.  相似文献   
130.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号