全文获取类型
收费全文 | 96292篇 |
免费 | 1488篇 |
国内免费 | 2005篇 |
专业分类
化学 | 38522篇 |
晶体学 | 959篇 |
力学 | 7103篇 |
综合类 | 12篇 |
数学 | 34423篇 |
物理学 | 18766篇 |
出版年
2023年 | 162篇 |
2022年 | 139篇 |
2021年 | 474篇 |
2020年 | 421篇 |
2019年 | 444篇 |
2018年 | 10709篇 |
2017年 | 10558篇 |
2016年 | 6753篇 |
2015年 | 1487篇 |
2014年 | 1051篇 |
2013年 | 1937篇 |
2012年 | 5310篇 |
2011年 | 12045篇 |
2010年 | 6554篇 |
2009年 | 7173篇 |
2008年 | 7689篇 |
2007年 | 9810篇 |
2006年 | 1168篇 |
2005年 | 2240篇 |
2004年 | 2722篇 |
2003年 | 2808篇 |
2002年 | 1777篇 |
2001年 | 612篇 |
2000年 | 568篇 |
1999年 | 363篇 |
1998年 | 398篇 |
1997年 | 329篇 |
1996年 | 380篇 |
1995年 | 276篇 |
1994年 | 195篇 |
1993年 | 241篇 |
1992年 | 173篇 |
1991年 | 143篇 |
1990年 | 135篇 |
1989年 | 134篇 |
1988年 | 130篇 |
1987年 | 117篇 |
1986年 | 125篇 |
1985年 | 144篇 |
1984年 | 145篇 |
1983年 | 108篇 |
1982年 | 110篇 |
1981年 | 101篇 |
1980年 | 108篇 |
1979年 | 81篇 |
1978年 | 71篇 |
1977年 | 59篇 |
1976年 | 45篇 |
1975年 | 43篇 |
1914年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
1.
Zlámalová M. Pitňa Lásková B. Vinarčíková M. Zukalová M. Kavan L. 《Journal of Solid State Electrochemistry》2022,26(3):639-647
Journal of Solid State Electrochemistry - The addition of nanocrystalline titanium dioxide (P90) to a cathode of Li/S cell enhances its voltammetric charge capacity by 19%, from which only a small... 相似文献
2.
Numerical Algorithms - An inverse central ordering of the nodes is proposed for the Newton interpolation formula. This ordering may improve the stability for certain distributions of nodes. For... 相似文献
3.
Garcia-Vicua Daniel Esparza Laida Mallor Fermin 《Central European Journal of Operations Research》2022,30(1):213-249
Central European Journal of Operations Research - This paper presents a discrete event simulation model to support decision-making for the short-term planning of hospital resource needs, especially... 相似文献
4.
Dariusz Marek Adam Domaski Joanna Domaska Jakub Szygua Tadeusz Czachrski Jerzy Klamka 《Entropy (Basel, Switzerland)》2021,23(5)
In this article, a way to employ the diffusion approximation to model interplay between TCP and UDP flows is presented. In order to control traffic congestion, an environment of IP routers applying AQM (Active Queue Management) algorithms has been introduced. Furthermore, the impact of the fractional controller and its parameters on the transport protocols is investigated. The controller has been elaborated in accordance with the control theory. The TCP and UDP flows are transmitted simultaneously and are mutually independent. Only the TCP is controlled by the AQM algorithm. Our diffusion model allows a single TCP or UDP flow to start or end at any time, which distinguishes it from those previously described in the literature. 相似文献
5.
Zayed Elsayed M. E. Shohib Reham M. A. Alngar Mohamed E. M. Yıldırım Yakup 《Computational Mathematics and Modeling》2021,32(2):235-252
Computational Mathematics and Modeling - Based on the extended simplest equation method, we construct solitons and other solutions for the nonlinear convection-diffusion-reaction equation with... 相似文献
6.
Redondo Mara Julia Romn Lucrecia Rossi Bertone Fiorela Verdecchia Melina 《Algebras and Representation Theory》2022,25(4):1037-1059
Algebras and Representation Theory - Let A and B be two Morita equivalent finite dimensional associative algebras over a field . It is well known that Hochschild cohomology is... 相似文献
7.
Martin Obst 《Aequationes Mathematicae》2018,92(1):135-163
Measuring angles in the Euclidean plane is a well-known topic, but for general normed planes there exists a variety of different concepts. These can be of a special kind, e.g. also preserving special orthogonality types. But these concepts are no angle measures in the sense of measure theory since they are not additive. This motivates us to define a new angle measure for normed planes that is in fact a measure in the sense of measure theory. Furthermore, we look at related types of rotation and reflection. 相似文献
8.
We analyze isolated resonance curves (IRCs) in single-degree-of-freedom systems possessing nonlinear damping. Through the combination of singularity theory and the averaging method, the onset and merging of IRCs, which coincide to isola and simple bifurcation singularities, respectively, can be analytically predicted. Numerical simulations confirm the accuracy of the analytical developments. Another important finding of this paper is that we unveil a geometrical connection between the topology of the damping force and IRCs. Specifically, we demonstrate that extremas and zeros of the damping force correspond to the appearance and merging of IRCs. Considering a damping force possessing several minima and maxima confirms the general validity of the analytical result. It also evidences a very complex scenario for which different IRCs are created, co-exist and then merge together to form a super IRC which eventually merges with the main resonance peak. 相似文献
9.
Arkadiusz Lewandowski 《Archiv der Mathematik》2018,111(5):503-511
We give the parameter version of a localization theorem for the Bergman metric near the boundary points of strictly pseudoconvex domains. The approximation theorem for square integrable holomorphic functions on such domains in the spirit of Graham-Kerzman is proved in the hereby paper, as well. 相似文献
10.