全文获取类型
收费全文 | 12431篇 |
免费 | 1000篇 |
国内免费 | 1342篇 |
专业分类
化学 | 1592篇 |
晶体学 | 26篇 |
力学 | 534篇 |
综合类 | 236篇 |
数学 | 10922篇 |
物理学 | 1463篇 |
出版年
2024年 | 12篇 |
2023年 | 130篇 |
2022年 | 180篇 |
2021年 | 224篇 |
2020年 | 308篇 |
2019年 | 344篇 |
2018年 | 319篇 |
2017年 | 357篇 |
2016年 | 391篇 |
2015年 | 318篇 |
2014年 | 585篇 |
2013年 | 980篇 |
2012年 | 497篇 |
2011年 | 681篇 |
2010年 | 605篇 |
2009年 | 776篇 |
2008年 | 900篇 |
2007年 | 858篇 |
2006年 | 776篇 |
2005年 | 698篇 |
2004年 | 563篇 |
2003年 | 610篇 |
2002年 | 512篇 |
2001年 | 403篇 |
2000年 | 411篇 |
1999年 | 365篇 |
1998年 | 318篇 |
1997年 | 328篇 |
1996年 | 227篇 |
1995年 | 151篇 |
1994年 | 124篇 |
1993年 | 102篇 |
1992年 | 84篇 |
1991年 | 87篇 |
1990年 | 49篇 |
1989年 | 40篇 |
1988年 | 55篇 |
1987年 | 27篇 |
1986年 | 33篇 |
1985年 | 46篇 |
1984年 | 43篇 |
1983年 | 25篇 |
1982年 | 33篇 |
1981年 | 44篇 |
1980年 | 30篇 |
1979年 | 28篇 |
1978年 | 30篇 |
1977年 | 20篇 |
1976年 | 19篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
本文应用上、下解方法和 Leray-Schauder不动点定理 ,证明了一类拟线性椭圆方程边值问题弱解的存在性 ,并且给出了一个应用实例 相似文献
22.
Mathematical economics has a long history and covers many interdisciplinary areas between mathematics and economics. At its center lies the theory of market equilibrium. The purpose of this expository article is to introduce mathematicians to price decentralization in general equilibrium theory. In particular, it concentrates on the role of positivity in the theory of convex economic analysis and the role of normal cones in the theory of non-convex economies. 相似文献
23.
24.
线性分式规划最优解集的求法 总被引:5,自引:0,他引:5
薛声家 《应用数学与计算数学学报》2002,16(1):90-96
本文使用多面集的表示定理,导出了线性分式规划最优解集的结构,并给出确定全部最优解的计算步骤。 相似文献
25.
We consider some Sobolev-type spaces and obtain a necessary and sufficient condition for their embedding in a Lebesgue space. 相似文献
26.
We establish the existence and stability of multidimensional transonic shocks for the Euler equations for steady potential compressible fluids. The Euler equations, consisting of the conservation law of mass and the Bernoulli law for the velocity, can be written as a second-order, nonlinear equation of mixed elliptic-hyperbolic type for the velocity potential. The transonic shock problem can be formulated into the following free boundary problem: The free boundary is the location of the transonic shock which divides the two regions of smooth flow, and the equation is hyperbolic in the upstream region where the smooth perturbed flow is supersonic. We develop a nonlinear approach to deal with such a free boundary problem in order to solve the transonic shock problem. Our results indicate that there exists a unique solution of the free boundary problem such that the equation is always elliptic in the downstream region and the free boundary is smooth, provided that the hyperbolic phase is close to a uniform flow. We prove that the free boundary is stable under the steady perturbation of the hyperbolic phase. We also establish the existence and stability of multidimensional transonic shocks near spherical or circular transonic shocks.
27.
We extend the matrix version of Cochran's statistical theorem to outer inverses of a matrix. As applications, we investigate the Wishartness and independence of matrix quadratic forms for Kronecker product covariance structures. 相似文献
28.
Suppose μ is a Radon measure on ℝ
d
, which may be non doubling. The only condition assumed on μ is a growth condition, namely, there is a constant C0>0 such that for all x∈supp(μ) and r>0, μ(B(x, r))⪯C0rn, where 0<n⪯d. We prove T1 theorem for non doubling measures with weak kernel conditions. Our approach yields new results
for kernels satisfying weakened regularity conditions, while recovering previously known Tolsa’s results. We also prove T1
theorem for Besov spaces on nonhomogeneous spaces with weak kernel conditions given in [7]. 相似文献
29.
Jeannette H. C. Woerner 《商业与工业应用随机模型》2005,21(1):27-44
In the framework of stochastic volatility models we examine estimators for the integrated volatility based on the pth power variation (i.e. the sum of pth absolute powers of the log‐returns). We derive consistency and distributional results for the estimators given high‐frequency data, especially taking into account what kind of process we may add to our model without affecting the estimate of the integrated volatility. This may on the one hand be interpreted as a possible flexibility in modelling, for example adding jumps or even leaving the framework of semimartingales by adding a fractional Brownian motion, or on the other hand as robustness against model misspecification. We will discuss possible choices of p under different model assumptions and irregularly spaced data. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
30.
The Iyengar Type Inequalities with Exact Estimations and the Chebyshev Central Algorithms of Integrals 总被引:3,自引:0,他引:3
Xing Hua WANG Shi Jun YANG 《数学学报(英文版)》2005,21(6):1361-1376
In this paper, both low order and high order extensions of the Iyengar type inequality are obtained. Such extensions are the best possible in the same sense as that of the Iyengar inequality. hzrthermore, the Chebyshev central algorithms of integrals for some function classes and some related problems are also considered and investigated. 相似文献