全文获取类型
收费全文 | 511451篇 |
免费 | 4859篇 |
国内免费 | 1248篇 |
专业分类
化学 | 257512篇 |
晶体学 | 7561篇 |
力学 | 24217篇 |
综合类 | 13篇 |
数学 | 70325篇 |
物理学 | 157930篇 |
出版年
2021年 | 3766篇 |
2020年 | 4185篇 |
2019年 | 4520篇 |
2018年 | 12402篇 |
2017年 | 12933篇 |
2016年 | 11901篇 |
2015年 | 6201篇 |
2014年 | 8641篇 |
2013年 | 20278篇 |
2012年 | 18924篇 |
2011年 | 28657篇 |
2010年 | 19067篇 |
2009年 | 18979篇 |
2008年 | 25863篇 |
2007年 | 28380篇 |
2006年 | 16405篇 |
2005年 | 19814篇 |
2004年 | 16188篇 |
2003年 | 14597篇 |
2002年 | 12873篇 |
2001年 | 13562篇 |
2000年 | 10330篇 |
1999年 | 7944篇 |
1998年 | 6602篇 |
1997年 | 6332篇 |
1996年 | 6225篇 |
1995年 | 5554篇 |
1994年 | 5473篇 |
1993年 | 5271篇 |
1992年 | 5888篇 |
1991年 | 5996篇 |
1990年 | 5725篇 |
1989年 | 5542篇 |
1988年 | 5571篇 |
1987年 | 5453篇 |
1986年 | 5161篇 |
1985年 | 6641篇 |
1984年 | 6789篇 |
1983年 | 5384篇 |
1982年 | 5467篇 |
1981年 | 5444篇 |
1980年 | 5038篇 |
1979年 | 5444篇 |
1978年 | 5587篇 |
1977年 | 5413篇 |
1976年 | 5388篇 |
1975年 | 4960篇 |
1974年 | 4932篇 |
1973年 | 4964篇 |
1972年 | 3492篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
T. Mihara K. Miyamoto M. Kida T. Sasaki N. Aoki Y. Ochiai 《Superlattices and Microstructures》2003,34(3-6):383
A multiwall carbon nanotube crossroads has been fabricated by a manipulation technique using a glass microcapillary, and the low temperature transport properties investigated. The two-terminal conductance of an individual tube shows Tomonaga–Luttinger liquid behavior G∝Tα at high temperature and dI/dV ∝V α at low temperature. However, no evidence of such a power-law behavior is obtained in the four-terminal conductance at the junction, where the conductance shows an almost metallic behavior ‘corrected’ by weak localization. Weak localization would essentially appear in electron states at the junctions of MWNTs. 相似文献
943.
Matter implies the existence of a large-scale connected cluster of a uniform nature. The appearance of such clusters as a function of hadron density is specified by percolation theory. We can therefore formulate the freeze-out of interacting hadronic matter in terms of the percolation of hadronic clusters. The resulting freeze-out condition as a function of temperature and baryo-chemical potential interpolates between resonance gas behavior at low baryon density and repulsive nucleonic matter at low temperature, and it agrees well with the data.Received: 10 September 2003, Published online: 7 November 2003 相似文献
944.
The periodic precipitation pattern formation in gelatinous media is interpreted as a moving boundary problem. The time law,
spacing law and width law are revisited on the basis of the new scenario. The explicit dependence of the geometric structure
on the initial concentrations of the reactants is derived. Matalon—Packter law, which relates the spacing coefficient with
the initial concentrations is reformulated removing many ambiguities and impractical parameters. Experimental results are
discussed to establish the significance of moving boundary concept in the diffusion controlled pattern forming systems 相似文献
945.
I. A. Stefanova 《Acoustical Physics》2003,49(2):203-206
Empirical approximating formulas describing the most important psychophysiological properties of the human auditory analyzer are derived. 相似文献
946.
This note investigates two long-standing conjectures on the Krull dimension of integer-valued polynomial rings and of polynomial rings in the context of (locally) essential domains.
947.
Bahraminasab A. Tabei S. M. A. Masoudi A. A. Shahbazi F. Reza Rahimi Tabar M. 《Journal of statistical physics》2004,116(5-6):1521-1544
The joint probability distribution function (PDF) of the height and its gradients is derived for a zero tension d + 1-dimensional Kardar-Parisi-Zhang (KPZ) equation. It is proved that the height's PDF of zero tension KPZ equation shows lack of positivity after a finite time t c . The properties of zero tension KPZ equation and its differences with the case that it possess an infinitesimal surface tension is discussed. Also potential relation between the time scale t c and the singularity time scale t c.v→0 of the KPZ equation with an infinitesimal surface tension is investigated. 相似文献
948.
In bricklayers' model, which is a generalization of the misanthrope processes, we show that a nontrivial class of product distributions is closed under the time-evolution of the process. This class also includes measures fitting to shock data of the limiting PDE. In particular, we show that shocks of this type with discontinuity of size one perform ordinary nearest neighbor random walks only interacting, in an attractive way, via their jump rates. Our results are related to those of Belitsky and Schütz(4) on the simple exclusion process, although we do not use quantum formalism as they do. The structures we find are described from a fixed position. Similar ones were found in Balázs,(2) valak as seen from the random position of the second class particle. 相似文献
949.
Christian J. Bordé Claus Lämmerzahl Ernst M. Rasel 《General Relativity and Gravitation》2004,36(10):2193-2196
950.
A. V. Burenin 《Optics and Spectroscopy》2004,97(6):867-875
A noninvariant geometrical group characterizing the internal dynamics of the tetrahydrofuran molecule C4H8O with allowance for the clearly pronounced pseudorotation effect is constructed. On this basis, some qualitative features of the energy spectrum of the molecule following from the analysis of high-resolution spectroscopic data are explained. 相似文献