全文获取类型
收费全文 | 742篇 |
免费 | 54篇 |
国内免费 | 53篇 |
专业分类
化学 | 207篇 |
力学 | 59篇 |
综合类 | 26篇 |
数学 | 406篇 |
物理学 | 151篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 15篇 |
2020年 | 14篇 |
2019年 | 12篇 |
2018年 | 19篇 |
2017年 | 21篇 |
2016年 | 20篇 |
2015年 | 23篇 |
2014年 | 29篇 |
2013年 | 39篇 |
2012年 | 39篇 |
2011年 | 35篇 |
2010年 | 25篇 |
2009年 | 35篇 |
2008年 | 46篇 |
2007年 | 43篇 |
2006年 | 33篇 |
2005年 | 31篇 |
2004年 | 26篇 |
2003年 | 19篇 |
2002年 | 27篇 |
2001年 | 25篇 |
2000年 | 16篇 |
1999年 | 26篇 |
1998年 | 22篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 25篇 |
1992年 | 21篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有849条查询结果,搜索用时 7 毫秒
81.
The mixed integer quadratic programming (MIQP) reformulation by Zheng, Sun, Li, and Cui (2012) for probabilistically constrained quadratic programs (PCQP) recently published in EJOR significantly dominates the standard MIQP formulation ( and ) which has been widely adopted in the literature. Stimulated by the dimensionality problem which Zheng et al. (2012) acknowledge themselves for their reformulations, we study further the characteristics of PCQP and develop new MIQP reformulations for PCQP with fewer variables and constraints. The results from numerical tests demonstrate that our reformulations clearly outperform the state-of-the-art MIQP in Zheng et al. (2012). 相似文献
82.
Received February 10, 1997 / Revised version received June 6, 1998 Published online October 9, 1998 相似文献
83.
Martin Gugat 《Mathematical Programming》1999,85(3):643-653
The growth of the multipliers, when the parameter approaches such a critical parameter, is characterized by a parametric constraint
qualification which is introduced here. It is equivalent to a bound on the growth of the multipliers.
Received May 8, 1995 / Revised version received February 12, 1998
Published online February 25, 1999 相似文献
84.
85.
Wajeb Gharibi Yong Xia 《高等学校计算数学学报(英文版)》2007,16(3):265-270
In this paper,we consider nonlinear infinity-norm minimization problems.We device a reliable Lagrangian dual approach for solving this kind of problems and based on this method we propose an algorithm for the mixed linear and nonlinear infinity- norm minimization problems.Numerical results are presented. 相似文献
86.
Summary The nonlinear CCSDTQ equations are written in a fully linearized form, via the introduction of computationally convenient intermediates. An efficient formulation of the coupled cluster method is proposed. Due to a recursive method for the calculation of intermediates, all computational steps involve the multiplication of an intermediate with aT vertex. This property makes it possible to express the CC equations exclusively in terms of matrix products which can be directly transformed into a highly vectorized program.This work has been supported by the U.S. Air Force Office of Scientific Research, Grant No. 90-0079 相似文献
87.
Charles Audet Pierre Hansen Frédéric Messine 《Journal of Combinatorial Theory, Series A》2007,114(1):135-150
The convex octagon with unit diameter and maximum perimeter is determined. This answers an open question dating from 1922. The proof uses geometric reasoning and an interval arithmetic based global optimization algorithm to solve a series of non-linear and non-convex programs involving trigonometric functions. 相似文献
88.
用集成电路制成程序控制器,示教板性能稳定,寿命长,效果好,操作方便.其主要部分由电源、时钟、逻辑电路、输出驱动器四部分组成. 相似文献
89.
In generalized fractional programming, one seeks to minimize the maximum of a finite number of ratios. Such programs are, in general, nonconvex and consequently are difficult to solve. Here, we consider a particular case in which the ratio is the quotient of a quadratic form and a positive concave function. The dual of such a problem is constructed and a numerical example is given. 相似文献
90.
O. L. Mangasarian 《Journal of Global Optimization》1995,6(2):153-161
The nonmonotone linear complementarity problem (LCP) is formulated as a bilinear program with separable constraints and an objective function that minimizes a natural error residual for the LCP. A linear-programming-based algorithm applied to the bilinear program terminates in a finite number of steps at a solution or stationary point of the problem. The bilinear algorithm solved 80 consecutive cases of the LCP formulation of the knapsack feasibility problem ranging in size between 10 and 3000, with almost constant average number of major iterations equal to four.This material is based on research supported by Air Force Office of Scientific Research Grant F49620-94-1-0036 and National Science Foundation Grants CCR-9322479 and CDA-9024618. 相似文献