全文获取类型
收费全文 | 3149篇 |
免费 | 267篇 |
国内免费 | 330篇 |
专业分类
化学 | 292篇 |
晶体学 | 2篇 |
力学 | 329篇 |
综合类 | 117篇 |
数学 | 2402篇 |
物理学 | 604篇 |
出版年
2024年 | 6篇 |
2023年 | 16篇 |
2022年 | 44篇 |
2021年 | 40篇 |
2020年 | 63篇 |
2019年 | 44篇 |
2018年 | 59篇 |
2017年 | 74篇 |
2016年 | 102篇 |
2015年 | 65篇 |
2014年 | 126篇 |
2013年 | 196篇 |
2012年 | 175篇 |
2011年 | 209篇 |
2010年 | 192篇 |
2009年 | 230篇 |
2008年 | 226篇 |
2007年 | 245篇 |
2006年 | 217篇 |
2005年 | 177篇 |
2004年 | 151篇 |
2003年 | 158篇 |
2002年 | 120篇 |
2001年 | 116篇 |
2000年 | 94篇 |
1999年 | 93篇 |
1998年 | 98篇 |
1997年 | 74篇 |
1996年 | 61篇 |
1995年 | 37篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 31篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1971年 | 1篇 |
1936年 | 2篇 |
排序方式: 共有3746条查询结果,搜索用时 0 毫秒
61.
62.
Heng-You Lan 《Journal of Mathematical Analysis and Applications》2007,327(1):481-493
In this paper, we introduce and study a new system of nonlinear A-monotone multivalued variational inclusions in Hilbert spaces. By using the concept and properties of A-monotone mappings, and the resolvent operator technique associated with A-monotone mappings due to Verma, we construct a new iterative algorithm for solving this system of nonlinear multivalued variational inclusions associated with A-monotone mappings in Hilbert spaces. We also prove the existence of solutions for the nonlinear multivalued variational inclusions and the convergence of iterative sequences generated by the algorithm. Our results improve and generalize many known corresponding results. 相似文献
63.
设T是m-增生算子,I是恒等映射.本文通过一个反例说明(T+λI)-1(λ>0)不一定是非扩张映射. 相似文献
64.
A multiparameter boundary-value problem of fresh infiltration water seepage in a drained fringe above quiescent saline water is solved in the direct statement and studied in detail. 相似文献
65.
研究函数族的正规性定则是复变函数论中的一个重要且有意义的工作.引进多元K-拟全纯函数的定义,并给出了多元K-拟全纯函数族的一个正规定则. 相似文献
66.
Summary Some stability and convergence theorems of the modified Ishikawa iterative sequences with errors for asymptotically nonexpansive
mapping in the intermediate sense and asymptotically pseudo contractive and uniformly Lipschitzian mappings in Banach spaces
are obtained. 相似文献
67.
《Surface and interface analysis : SIA》2006,38(1):19-24
We have been developing a new analytical transmission electron microscope (TEM), called a coincidence TEM, which in principle enables elemental mapping images to be observed at a high signal‐to‐noise (S/N) ratio under very low dose radiation conditions. In this paper, we report the development of a coincidence TEM with a digital waveform measuring system for obtaining a coincidence elemental mapping image. In this system, analog signals detected by a Si(Li) detector and a multianode, position‐sensitive photomultiplier (PSPM) are continuously converted into 12‐bit digital waveform data at a rate of 100 MHz, and transferred to a PC. From the transferred digital waveform data, information on X‐ray photon energy, electron incident position, and detection times of both X rays and electrons are calculated by digital waveform measurement, which lead to the observation of a successful coincidence elemental mapping image. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
68.
A. Shapiro 《Journal of Optimization Theory and Applications》1990,66(3):477-487
Various definitions of directional derivatives in topological vector spaces are compared. Directional derivatives in the sense of Gâteaux, Fréchet, and Hadamard are singled out from the general framework of -directional differentiability. It is pointed out that, in the case of finite-dimensional spaces and locally Lipschitz mappings, all these concepts of directional differentiability are equivalent. The chain rule for directional derivatives of a composite mapping is discussed. 相似文献
69.
Ion mobility spectrometry (IMS) measurement combined with unsupervised neurocomputing is considered as a new potential method for on-line monitoring of fermentation and other processes producing volatile compounds that involve micro-organisms. This was demonstrated in a model system in which a strain of brewer’s yeast (Saccharomyces cerevisiae) was cultivated in a bench-top fermenter. Five phases of yeast growth could be detected from measurements of the exhaust gases from the fermenter, as indicated by the changes in ion mobility spectra analysed by computational methods.The data were first processed using the Self-Organizing Map (SOM) algorithm, the results showing that the phases of fermentation can be detected and identified. The cultivations were also shown by Sammon’s mapping to be comparable to a certain level of accuracy. Contaminated cultivation could be detected by its distinctive ion mobility spectrometry profile. 相似文献
70.
Summary A set of algorithms designed to enhance the display of protein binding cavities is presented. These algorithms, collectively entitled CAVITY SEARCH, allow the user to isolate and fully define the extent of a particular cavity. Solid modeling techniques are employed to produce a detailed cast of the active site region, which can then be color-coded to show electrostatic and steric interactions between the protein cavity and a bound ligand. 相似文献