全文获取类型
收费全文 | 227318篇 |
免费 | 3441篇 |
国内免费 | 747篇 |
专业分类
化学 | 126204篇 |
晶体学 | 3454篇 |
力学 | 8671篇 |
综合类 | 9篇 |
数学 | 24460篇 |
物理学 | 68708篇 |
出版年
2018年 | 1730篇 |
2017年 | 1659篇 |
2016年 | 3259篇 |
2015年 | 2440篇 |
2014年 | 3252篇 |
2013年 | 9493篇 |
2012年 | 6911篇 |
2011年 | 8365篇 |
2010年 | 5565篇 |
2009年 | 5354篇 |
2008年 | 7635篇 |
2007年 | 7673篇 |
2006年 | 7353篇 |
2005年 | 6700篇 |
2004年 | 6116篇 |
2003年 | 5330篇 |
2002年 | 5131篇 |
2001年 | 6390篇 |
2000年 | 4949篇 |
1999年 | 3904篇 |
1998年 | 3056篇 |
1997年 | 3093篇 |
1996年 | 3138篇 |
1995年 | 2899篇 |
1994年 | 2820篇 |
1993年 | 2725篇 |
1992年 | 3236篇 |
1991年 | 2943篇 |
1990年 | 2897篇 |
1989年 | 2912篇 |
1988年 | 2838篇 |
1987年 | 2845篇 |
1986年 | 2643篇 |
1985年 | 3652篇 |
1984年 | 3617篇 |
1983年 | 3005篇 |
1982年 | 3209篇 |
1981年 | 3137篇 |
1980年 | 3043篇 |
1979年 | 3194篇 |
1978年 | 3406篇 |
1977年 | 3244篇 |
1976年 | 3137篇 |
1975年 | 2980篇 |
1974年 | 2907篇 |
1973年 | 2906篇 |
1972年 | 1873篇 |
1968年 | 2073篇 |
1967年 | 2313篇 |
1966年 | 2059篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
11.
Alawainati F. A. Manaa H. Henari F. Z. Biyiklioglu Z. Arslan T. Jaafar A. 《Journal of Applied Spectroscopy》2021,88(5):951-957
Journal of Applied Spectroscopy - Detailed measurements of nonlinear optical properties and optical limiting for four phthalocyanine (Pc) derivatives (PcCo, PcCu, PcMn, and PcSi) are reported. The... 相似文献
12.
Analysis Mathematica - We introduce and study the k-Hankel Gabor transform. We investigate the localization operators for this transform. In particular, we study their trace class properties and we... 相似文献
13.
14.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
15.
Vasile M. Loots H. Vercammen L. Bruggeman M. Verrezen F. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(8):3349-3357
Journal of Radioanalytical and Nuclear Chemistry - In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine... 相似文献
16.
17.
Laurens Kooijman Dr. Matthias Schuster Christian Baumann Simon Jurt Dr. Frank Löhr Dr. Boris Fürtig Prof. Dr. Peter Güntert Prof. Dr. Oliver Zerbe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21151-21158
To achieve efficient proton pumping in the light-driven proton pump bacteriorhodopsin (bR), the protein must be tightly coupled to the retinal to rapidly convert retinal isomerization into protein structural rearrangements. Methyl group dynamics of bR embedded in lipid nanodiscs were determined in the dark-adapted state, and were found to be mostly well ordered at the cytosolic side. Methyl groups in the M145A mutant of bR, which displays only 10 % residual proton pumping activity, are less well ordered, suggesting a link between side-chain dynamics on the cytosolic side of the bR cavity and proton pumping activity. In addition, slow conformational exchange, attributed to low frequency motions of aromatic rings, was indirectly observed for residues on the extracellular side of the bR cavity. This may be related to reorganization of the water network. These observations provide a detailed picture of previously undescribed equilibrium dynamics on different time scales for ground-state bR. 相似文献
18.
Cavitation erosion is caused in solids exposed to strong pressure waves developing in an adjacent fluid field. The knowledge of the transient distribution of stresses in the solid is important to understand the cause of damaging by comparisons with breaking points of the material. The modeling of this problem requires the coupling of the models for the fluid and the solid. For this purpose, we use a strategy based on the solution of coupled Riemann problems that has been originally developed for the coupling of 2 fluids. This concept is exemplified for the coupling of a linear elastic structure with an ideal gas. The coupling procedure relies on the solution of a nonlinear equation. Existence and uniqueness of the solution is proven. The coupling conditions are validated by means of quasi‐1D problems for which an explicit solution can be determined. For a more realistic scenario, a 2D application is considered where in a compressible single fluid, a hot gas bubble at low pressure collapses in a cold gas at high pressure near an adjacent structure. 相似文献
19.
20.
The European Physical Journal Special Topics - The removal of suspended particles from the interior of a thermocapillary liquid bridge via a finite-particle-size effect restricting the particle... 相似文献