全文获取类型
收费全文 | 7736篇 |
免费 | 1083篇 |
国内免费 | 434篇 |
专业分类
化学 | 818篇 |
晶体学 | 29篇 |
力学 | 1634篇 |
综合类 | 186篇 |
数学 | 3017篇 |
物理学 | 3569篇 |
出版年
2024年 | 8篇 |
2023年 | 62篇 |
2022年 | 99篇 |
2021年 | 153篇 |
2020年 | 208篇 |
2019年 | 177篇 |
2018年 | 210篇 |
2017年 | 234篇 |
2016年 | 259篇 |
2015年 | 243篇 |
2014年 | 368篇 |
2013年 | 585篇 |
2012年 | 357篇 |
2011年 | 394篇 |
2010年 | 303篇 |
2009年 | 375篇 |
2008年 | 459篇 |
2007年 | 530篇 |
2006年 | 443篇 |
2005年 | 366篇 |
2004年 | 338篇 |
2003年 | 349篇 |
2002年 | 324篇 |
2001年 | 301篇 |
2000年 | 344篇 |
1999年 | 276篇 |
1998年 | 225篇 |
1997年 | 174篇 |
1996年 | 148篇 |
1995年 | 139篇 |
1994年 | 127篇 |
1993年 | 104篇 |
1992年 | 77篇 |
1991年 | 90篇 |
1990年 | 55篇 |
1989年 | 44篇 |
1988年 | 52篇 |
1987年 | 45篇 |
1986年 | 31篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 14篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 9篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1973年 | 12篇 |
排序方式: 共有9253条查询结果,搜索用时 0 毫秒
11.
The large deviation principle (LDP) which has been effectively used in queueing analysis is the sample path LDP, the LDP in a function space endowed with the uniform topology. Chang [5] has shown that in the discrete-time G/D/1 queueing system under the FIFO discipline, the departure process satisfies the sample path LDP if so does the arrival process. In this paper, we consider arrival processes satisfying the LDP in a space of measures endowed with the weak* topology (Lynch and Sethuraman [12]) which holds under a weaker condition. It is shown that in the queueing system mentioned above, the departure processes still satisfies the sample path LDP. Our result thus covers arrival processes which can be ruled out in the work of Chang [5]. The result is then applied to obtain the exponential decay rate of the queue length probability in an intree network as was obtained by Chang [5], who considered the arrival process satisfying the sample path LDP. 相似文献
12.
Kasper K. Berthelsen Jesper Møller 《Bulletin of the Brazilian Mathematical Society》2002,33(3):351-367
This primer provides a self-contained exposition of the case where spatial birth-and-death processes are used for perfect
simulation of locally stable point processes. Particularly, a simple dominating coupling from the past (CFTP) algorithm and
the CFTP algorithms introduced in [13], [14], and [5] are studied. Some empirical results for the algorithms are discussed.
Received: 30 June 2002 相似文献
13.
Let G=(V(G),E(G)) be a graph. A (n,G, λ)‐GD is a partition of the edges of λKn into subgraphs (G‐blocks), each of which is isomorphic to G. The (n,G,λ)‐GD is named as graph design for G or G‐decomposition. The large set of (n,G,λ)‐GD is denoted by (n,G,λ)‐LGD. In this work, we obtain the existence spectrum of (n,P3,λ)‐LGD. © 2002 Wiley Periodicals, Inc. J Combin Designs 10: 151–159, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jcd.10008 相似文献
14.
Alexander Krasnosel'skii Dmitrii Rachinskii 《NoDEA : Nonlinear Differential Equations and Applications》2002,9(1):93-115
We consider autonomous systems with a nonlinear part depending on a parameter and study Hopf bifurcations at infinity. The
nonlinear part consists of the nonlinear functional term and the Prandtl--Ishlinskii hysteresis term. The linear part of the
system has a special form such that the close-loop system can be considered as a hysteresis perturbation of a quasilinear
Hamiltonian system. The Hamiltonian system has a continuum of arbitrarily large cycles for each value of the parameter. We
present sufficient conditions for the existence of bifurcation points for the non-Hamiltonian system with hysteresis. These
bifurcation points are determined by simple characteristics of the hysteresis nonlinearity. 相似文献
15.
A multi-exposure of color fringes method has been developed to improve the capture speed of a conventional color CCD camera. In the method, four groups of projected fringe patterns encoded with different colors and different directions are stored in one CCD frame. Therefore the capture frequency of the conventional CCD can be improved to 200 Hz. It is available to measure the insect wings with low beating frequency, such as dragonfly, moth, or butterfly, whose beating frequency is about 30–40 Hz. We have used the method to measure the beating motion of a moth successfully. 相似文献
16.
17.
股票价格遵循几何分式Brown运动的期权定价 总被引:6,自引:0,他引:6
讨论了股票价格过程遵循几何分式B row n运动的欧式期权定价.由于该过程存在套利机会使得传统的期权定价方法(如资本资产定价模型(CAPM),套利定价模型(APT),动态均衡定价理论(DEPT))不可能对该期权定价.利用保险精算定价法,在对市场无其它任何假设条件下,获得了欧式期权的定价公式.并讨论了在有效期内股票支付已知红利和红利率的推广公式. 相似文献
18.
19.
通过分析计算,设计了一种大口径宽视场折射式红外相机光学系统。该系统设计用于超长线阵扫描红外相机的地面演示成像,它能同时对短波2μm—3μm、中波3μm—4.5μm双波段成像,且同时具有24°的大视场和150mm的宽口径,成像质量接近衍射极限。该系统在航天遥感领域应用广泛。 相似文献
20.
介绍了13~18世纪物理学史和科技史上曾名噪一时的第一类永动机的设计方案的破灭.第一类永动机幻梦破灭的历史引起了人们的反思与启示,有力地促进了19世纪中叶能量转化和守恒定律的确立. 相似文献