全文获取类型
收费全文 | 1044篇 |
免费 | 8篇 |
国内免费 | 12篇 |
专业分类
化学 | 367篇 |
晶体学 | 2篇 |
力学 | 19篇 |
数学 | 335篇 |
物理学 | 341篇 |
出版年
2020年 | 10篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 24篇 |
2015年 | 7篇 |
2014年 | 15篇 |
2013年 | 46篇 |
2012年 | 43篇 |
2011年 | 46篇 |
2010年 | 23篇 |
2009年 | 17篇 |
2008年 | 32篇 |
2007年 | 47篇 |
2006年 | 56篇 |
2005年 | 50篇 |
2004年 | 39篇 |
2003年 | 27篇 |
2002年 | 26篇 |
2001年 | 13篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 10篇 |
1997年 | 11篇 |
1996年 | 24篇 |
1995年 | 24篇 |
1994年 | 26篇 |
1993年 | 27篇 |
1992年 | 30篇 |
1991年 | 21篇 |
1990年 | 17篇 |
1989年 | 10篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 18篇 |
1984年 | 20篇 |
1983年 | 14篇 |
1982年 | 20篇 |
1981年 | 16篇 |
1980年 | 10篇 |
1979年 | 16篇 |
1978年 | 14篇 |
1977年 | 14篇 |
1976年 | 13篇 |
1975年 | 17篇 |
1974年 | 13篇 |
1928年 | 6篇 |
1926年 | 5篇 |
1924年 | 4篇 |
排序方式: 共有1064条查询结果,搜索用时 15 毫秒
91.
Robert Gilmer William Heinzer Moshe Roitman 《Proceedings of the American Mathematical Society》1999,127(11):3141-3151
Suppose is a maximal ideal of a commutative integral domain and that some power of is finitely generated. We show that is finitely generated in each of the following cases: (i) is of height one, (ii) is integrally closed and , (iii) is a monoid domain over a field , where is a cancellative torsion-free monoid such that , and is the maximal ideal . We extend the above results to ideals of a reduced ring such that is Noetherian. We prove that a reduced ring is Noetherian if each prime ideal of has a power that is finitely generated. For each with , we establish existence of a -dimensional integral domain having a nonfinitely generated maximal ideal of height such that is -generated.
92.
Yair Shapira Moshe Israeli Avram Sidi Uzi Zrahia 《Numerical Methods for Partial Differential Equations》1999,15(5):535-543
Spectral element schemes for the solution of elliptic boundary value problems are considered. Preconditioning methods based on finite difference and finite element schemes are implemented. Numerical experiments show that inverting the preconditioner by a single multigrid iteration is most efficient and that the finite difference preconditioner is superior to the finite element one for both definite and indefinite problems. A multigrid preconditioner is also derived from the finite difference preconditioner and is found suitable for the CGS acceleration method. It is pointed out that, for the finite difference and finite element preconditioners, CGS does not always converge to the accurate algebraic solution. © 1999 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 15: 535–543, 1999 相似文献
93.
Moshe Sniedovich 《Operations Research Letters》1985,4(1):19-21
This paper presents the essentials of a method designed to solve optimization problems whose objective functions are of the form g(x)+ ψ(u(x)), where ψ is differentiable and either concave or convex. It is shown that solutions to such problems can be obtained through the solutions of the Lagrangian problem whose objective function is of the form g(x)+ λu(x). 相似文献
94.
Moshe Stupel Victor Oxman Avi Sigler 《International Journal of Mathematical Education in Science & Technology》2017,48(1):149-161
We present a geometrical investigation of the process of creating an infinite sequence of triangles inscribed in a circle, whose areas, perimeters and lengths of radii of the inscribed circles tend to a limit in a monotonous manner.First, using geometrical software, we investigate four theorems that represent interesting geometrical properties, after which we present formal proofs that rest on a combination between different fields of mathematics: trigonometry, algebra and geometry, and the use of the concept of standard deviation that is taken from statistics. 相似文献
95.
96.
97.
Moshe Sniedovich 《Mathematical Programming》1989,43(1-3):329-347
We propose a solution strategy for fractional programming problems of the form max
xx
g(x)/ (u(x)), where the function satisfies certain convexity conditions. It is shown that subject to these conditions optimal solutions to this problem can be obtained from the solution of the problem max
xx
g(x) + u(x), where is an exogenous parameter. The proposed strategy combines fractional programming andc-programming techniques. A maximal mean-standard deviation ratio problem is solved to illustrate the strategy in action. 相似文献
98.
Moshe Dror 《Discrete Applied Mathematics》2010,158(16):1767-1776
We examine computational complexity implications for scheduling problems with job precedence relations with respect to strong precedence versus weak precedence. We propose a consistent definition of strong precedence for chains, trees, and series-parallel orders. Using modular decomposition for partially ordered sets (posets), we restate and extend past complexity results for chains and trees as summarized in Dror (1997) [5]. Moreover, for series-parallel posets we establish new computational complexity results for strong precedence constraints for single- and multi-machine problems. 相似文献
99.
100.
Moshe Shaked 《Annals of the Institute of Statistical Mathematics》1979,31(1):67-84
In this work we consider some familiar and some new concepts of positive dependence for interchangeable bivariate distributions.
By characterizing distributions which are positively dependent according to some of these concepts, we indicate real situations
in which these concepts arise naturally. For the various families of positively dependent distributions we prove some closure
properties and demonstrate all the possible logical relations. Some inequalities are shown and applied to determine whether
under- (or over-) estimates, of various probabilistic quantities, occur when a positively dependent distribution is assumed
(falsely) to be the product of its marginals (that is, when two positively dependent random variables are assumed, falsely,
to be independent). Specific applications in reliability theory, statistical mechanics and reversible Markov processes are
discussed.
This work was partially supported by National Science Foundation GP-30707X1. It is part of the author's Ph.D. dissertation
prepared at the University of Rochester and supervised by A. W. Marshall.
Now at Indiana University. 相似文献