全文获取类型
收费全文 | 791009篇 |
免费 | 6619篇 |
国内免费 | 2091篇 |
专业分类
化学 | 374088篇 |
晶体学 | 10914篇 |
力学 | 45359篇 |
综合类 | 36篇 |
数学 | 135919篇 |
物理学 | 233403篇 |
出版年
2021年 | 6599篇 |
2020年 | 7165篇 |
2019年 | 8164篇 |
2018年 | 20656篇 |
2017年 | 20514篇 |
2016年 | 21090篇 |
2015年 | 9113篇 |
2014年 | 14537篇 |
2013年 | 31776篇 |
2012年 | 27904篇 |
2011年 | 38419篇 |
2010年 | 27352篇 |
2009年 | 27745篇 |
2008年 | 33541篇 |
2007年 | 35136篇 |
2006年 | 25223篇 |
2005年 | 23396篇 |
2004年 | 22143篇 |
2003年 | 20683篇 |
2002年 | 19749篇 |
2001年 | 20044篇 |
2000年 | 15681篇 |
1999年 | 12119篇 |
1998年 | 10739篇 |
1997年 | 10447篇 |
1996年 | 9840篇 |
1995年 | 8735篇 |
1994年 | 8749篇 |
1993年 | 8575篇 |
1992年 | 8891篇 |
1991年 | 9484篇 |
1990年 | 9121篇 |
1989年 | 9062篇 |
1988年 | 8704篇 |
1987年 | 8548篇 |
1986年 | 8133篇 |
1985年 | 10311篇 |
1984年 | 10755篇 |
1983年 | 9084篇 |
1982年 | 9440篇 |
1981年 | 8887篇 |
1980年 | 8378篇 |
1979年 | 9196篇 |
1978年 | 9474篇 |
1977年 | 9468篇 |
1976年 | 9500篇 |
1975年 | 9099篇 |
1974年 | 8861篇 |
1973年 | 9186篇 |
1972年 | 7006篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Russian Physics Journal - The paper shows that the values of zero-point energy and vibrations of atoms in a crystal determined by the uncertainty principle, depend on the dynamic response of atoms.... 相似文献
112.
Journal of Applied and Industrial Mathematics - We study the problem of optimal location of the ambulance fleet at the base stations. The objective is to minimize the average waiting time for... 相似文献
113.
114.
115.
116.
Physics of Particles and Nuclei Letters - When creating accelerators and storage-ring installations in a compact space, there is not always enough space for all the necessary magnet elements. In... 相似文献
117.
Dr. Kathiravan Murugesan Vishwas G. Chandrashekhar Dr. Carsten Kreyenschulte Prof. Dr. Matthias Beller Dr. Rajenahally V. Jagadeesh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17561-17565
Herein, we report the synthesis of specific silica-supported Co/Co3O4 core–shell based nanoparticles prepared by template synthesis of cobalt-pyromellitic acid on silica and subsequent pyrolysis. The optimal catalyst material allows for general and selective hydrogenation of pyridines, quinolines, and other heteroarenes including acridine, phenanthroline, naphthyridine, quinoxaline, imidazo[1,2-a]pyridine, and indole under comparably mild reaction conditions. In addition, recycling of these Co nanoparticles and their ability for dehydrogenation catalysis are showcased. 相似文献
118.
Paired single residue‐transposed Lys‐N and Lys‐C digestions for label‐free identification of N‐terminal and C‐terminal MS/MS peptide product ions: ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry and tandem mass spectrometry for peptide de novo sequencing
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)
119.
The influence of different referencing methods on the accuracy of δ13C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)
120.
ABSTRACTThe Coupled-Cluster (CC) theory is one of the most successful high precision methods used to solve the stationary Schrödinger equation. In this article, we address the mathematical foundation of this theory with focus on the advances made in the past decade. Rather than solely relying on spectral gap assumptions (non-degeneracy of the ground state), we highlight the importance of coercivity assumptions – Gårding type inequalities – for the local uniqueness of the CC solution. Based on local strong monotonicity, different sufficient conditions for a local unique solution are suggested. One of the criteria assumes the relative smallness of the total cluster amplitudes (after possibly removing the single amplitudes) compared to the Gårding constants. In the extended CC theory the Lagrange multipliers are wave function parameters and, by means of the bivariational principle, we here derive a connection between the exact cluster amplitudes and the Lagrange multipliers. This relation might prove useful when determining the quality of a CC solution. Furthermore, the use of an Aubin–Nitsche duality type method in different CC approaches is discussed and contrasted with the bivariational principle. 相似文献