全文获取类型
收费全文 | 134431篇 |
免费 | 11574篇 |
国内免费 | 7903篇 |
专业分类
化学 | 47156篇 |
晶体学 | 2182篇 |
力学 | 8639篇 |
综合类 | 1191篇 |
数学 | 37233篇 |
物理学 | 57507篇 |
出版年
2023年 | 663篇 |
2022年 | 2301篇 |
2021年 | 2106篇 |
2020年 | 1987篇 |
2019年 | 2209篇 |
2018年 | 1961篇 |
2017年 | 1856篇 |
2016年 | 1952篇 |
2015年 | 1887篇 |
2014年 | 3231篇 |
2013年 | 5691篇 |
2012年 | 3509篇 |
2011年 | 4485篇 |
2010年 | 4863篇 |
2009年 | 9716篇 |
2008年 | 10909篇 |
2007年 | 9488篇 |
2006年 | 8284篇 |
2005年 | 6108篇 |
2004年 | 5789篇 |
2003年 | 5807篇 |
2002年 | 8681篇 |
2001年 | 5244篇 |
2000年 | 4798篇 |
1999年 | 4462篇 |
1998年 | 3753篇 |
1997年 | 2925篇 |
1996年 | 2617篇 |
1995年 | 2970篇 |
1994年 | 2822篇 |
1993年 | 2341篇 |
1992年 | 1813篇 |
1991年 | 1354篇 |
1990年 | 1104篇 |
1989年 | 949篇 |
1988年 | 949篇 |
1987年 | 687篇 |
1986年 | 500篇 |
1985年 | 1373篇 |
1984年 | 957篇 |
1983年 | 705篇 |
1982年 | 1005篇 |
1981年 | 1149篇 |
1980年 | 1022篇 |
1979年 | 912篇 |
1978年 | 835篇 |
1977年 | 693篇 |
1976年 | 661篇 |
1974年 | 425篇 |
1973年 | 579篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
《Mendeleev Communications》2022,32(4):534-536
Correlation times and diffusion coefficients of water molecules were measured for the first time by 1H spin relaxation and pulsed field gradient NMR in Li+, Na+ and Cs+ ionic forms of Nafion 117 membrane. Hydration numbers of Li+, Na+ and Cs+ cations were calculated. It was shown that at high humidity macroscopic transfer is controlled by the local translational motion of water molecules. 相似文献
3.
4.
5.
《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2021,38(5):1337-1371
In this paper we consider minimizers of the functional where is a bounded open set and where are the first k eigenvalues on Ω of an operator in divergence form with Dirichlet boundary condition and with Hölder continuous coefficients. We prove that the optimal sets have finite perimeter and that their free boundary is composed of a regular part, which is locally the graph of a -regular function, and a singular part, which is empty if , discrete if and of Hausdorff dimension at most if , for some . 相似文献
6.
7.
《Mendeleev Communications》2022,32(4):507-509
We report on the synthesis of new Ru(bpy)2(phen) catalyst for the oscillatory Belousov–Zhabotinsky chemical reaction and on the preparation of novel Ru(bpy)2(phen)-based self-oscillating gels. The synthesized gels exhibit high-amplitude autonomous mechanical oscillations when the Belousov–Zhabotinsky reaction proceeds inside these gels 相似文献
8.
Dr. Joaquim Torra Dr. Felipe Viela Dr. Diego Megías Dr. Begoña Sot Prof. Cristina Flors 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200026
CRANAD-2 is a fluorogenic curcumin derivative used for near-infrared detection and imaging in vivo of amyloid aggregates, which are involved in neurodegenerative diseases. We explore the performance of CRANAD-2 in two super-resolution imaging techniques, namely stimulated emission depletion (STED) and single-molecule localization microscopy (SMLM), with markedly different fluorophore requirements. By conveniently adapting the concentration of CRANAD-2, which transiently binds to amyloid fibrils, we show that it performs well in both techniques, achieving a resolution in the range of 45–55 nm. Correlation of SMLM with atomic force microscopy (AFM) validates the resolution of fine features in the reconstructed super-resolved image. The good performance and versatility of CRANAD-2 provides a powerful tool for near-infrared nanoscopic imaging of amyloids in vitro and in vivo. 相似文献
9.
In this article, we construct and analyze a residual-based a posteriori error estimator for a quadratic finite volume method (FVM) for solving nonlinear elliptic partial differential equations with homogeneous Dirichlet boundary conditions. We shall prove that the a posteriori error estimator yields the global upper and local lower bounds for the norm error of the FVM. So that the a posteriori error estimator is equivalent to the true error in a certain sense. Numerical experiments are performed to illustrate the theoretical results. 相似文献
10.