全文获取类型
收费全文 | 22056篇 |
免费 | 2446篇 |
国内免费 | 2347篇 |
专业分类
化学 | 2302篇 |
晶体学 | 33篇 |
力学 | 1868篇 |
综合类 | 585篇 |
数学 | 16065篇 |
物理学 | 5996篇 |
出版年
2024年 | 22篇 |
2023年 | 177篇 |
2022年 | 263篇 |
2021年 | 372篇 |
2020年 | 441篇 |
2019年 | 478篇 |
2018年 | 486篇 |
2017年 | 643篇 |
2016年 | 743篇 |
2015年 | 540篇 |
2014年 | 1110篇 |
2013年 | 1452篇 |
2012年 | 1165篇 |
2011年 | 1389篇 |
2010年 | 1270篇 |
2009年 | 1525篇 |
2008年 | 1534篇 |
2007年 | 1628篇 |
2006年 | 1435篇 |
2005年 | 1364篇 |
2004年 | 1105篇 |
2003年 | 1025篇 |
2002年 | 854篇 |
2001年 | 787篇 |
2000年 | 727篇 |
1999年 | 625篇 |
1998年 | 553篇 |
1997年 | 530篇 |
1996年 | 388篇 |
1995年 | 309篇 |
1994年 | 260篇 |
1993年 | 195篇 |
1992年 | 172篇 |
1991年 | 147篇 |
1990年 | 147篇 |
1989年 | 99篇 |
1988年 | 92篇 |
1987年 | 85篇 |
1986年 | 72篇 |
1985年 | 95篇 |
1984年 | 74篇 |
1983年 | 54篇 |
1982年 | 77篇 |
1981年 | 69篇 |
1980年 | 50篇 |
1979年 | 43篇 |
1978年 | 35篇 |
1977年 | 30篇 |
1976年 | 31篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
71.
林正炎 《数学物理学报(B辑英文版)》2003,23(3)
Let {X_n, n≥1} be a strictly stationary sequence of random variables, whichare either associated or negatively associated, f(·) be their common density. In this paper,the author shows a central limit theorem for a kernel estimate of f(·) under certain regularconditions. 相似文献
72.
Chin-Tsang Chiang Mei-Cheng Wang 《Annals of the Institute of Statistical Mathematics》2004,56(1):87-100
This paper proposes kernel estimation of the occurrence rate function for recurrent event data with informative censoring.
An informative censoring model is considered with assumptions made on the joint distribution of the recurrent event process
and the censoring time without modeling the censoring distribution. Under the validity of the informative censoring model,
we also show that an estimator based on the assumption of independent censoring becomes inappropriate and is generally asymptotically
biased. To investigate the asymptotic properties of the proposed estimator, the explicit form of its asymptotic mean squared
risk and the asymptotic normality are derived. Meanwhile, the empirical consistent smoothing estimator for the variance function
of the estimator is suggested. The performance of the estimators are also studied through Monte Carlo simulations. An epidemiological
example of intravenous drug user data is used to show the influence of informative censoring in the estimation of the occurrence
rate functions for inpatient cares over time. 相似文献
73.
袁文俊 《数学物理学报(A辑)》2003,23(2):224-230
该文考虑具有控制系数 A\-0 和系数仅有有限个极点的高阶线性齐次微分方程(1.1)。得到了一个复振荡结果,该结果是J. K. Langley[11]等作者在整系数下相应结果的推广。 相似文献
74.
75.
A locally convex space is said to be a Gateaux differentiability space (GDS)provided every continuous convex function defined on a nonempty convex open subset D of the space is densely Gateaux differentiable in D.This paper shows that the product of a GDS and a family of separable Frechet spaces is a GDS,and that the product of a GDS and an arbitrary locally convex space endowed with the weak topology is a GDS. 相似文献
76.
给出了Banach空间的一个增算子不动点定理,将这一定理应用到Banach空间的积分-微分方程,给出了一类积分-微分方程的连续可微最大解和连续可微最小解的存在性定理. 相似文献
77.
J. Giroire T. Ha‐Duong V. Moumas 《Mathematical Methods in the Applied Sciences》2005,28(13):1527-1552
This article deals with a boundary value problem for Laplace equation with a non‐linear and non‐local boundary condition. This problem comes from petroleum engineering and is used to obtain an estimation of well productivity. The non‐linear and non‐local boundary condition is written on the well boundary. On the outer reservoir boundaries, we have both Dirichlet and Neumann conditions. In this paper, we prove the existence and uniqueness of a solution to this problem. The existence is proved by Schauder theorem and the uniqueness is obtained under more restricted conditions, when the involved operator is a contraction. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
78.
本文考虑广义C-R组^[1](H)的解f=u iv jw∈C^2的一些性质,提出与之相关的两个边值问题,用积分方程方法和调和函数性质证明了边值问题解的存在唯一性,并写出解的积分表达式. 相似文献
79.
研究了Banach空间中非线性混合型微分-积分方程初值问题u′=f(t,u,Tu,Su),u(0)=x0的整体解,完全没有要求f的任何增性,利用Mnch不动点定理和比较结果得到了初值问题整体解的存在性和唯一解,并且给出了一致收敛于唯一解的迭代序列,改进推广和统一了已有的许多结果. 相似文献
80.
We present a practical polynomial-time algorithm for computing the
zeta function of a Kummer curve over a finite field of small
characteristic. Such algorithms have recently been obtained using a
method of Kedlaya based upon Monsky–Washnitzer cohomology, and are of
interest in cryptography. We take a different approach.
The problem is reduced to that of computing the L-function
of a multiplicative character sum. This latter task is achieved via a
cohomological formula based upon the work of Dwork and Reich. We show,
however, that our method and that of Kedlaya are very closely related.Dedicated to the memory of Gian-Carlo Rota 相似文献