全文获取类型
收费全文 | 17237篇 |
免费 | 528篇 |
国内免费 | 184篇 |
专业分类
化学 | 6901篇 |
晶体学 | 372篇 |
力学 | 1069篇 |
综合类 | 6篇 |
数学 | 1548篇 |
物理学 | 8053篇 |
出版年
2023年 | 92篇 |
2022年 | 222篇 |
2021年 | 216篇 |
2020年 | 144篇 |
2019年 | 162篇 |
2018年 | 254篇 |
2017年 | 204篇 |
2016年 | 355篇 |
2015年 | 277篇 |
2014年 | 415篇 |
2013年 | 787篇 |
2012年 | 1018篇 |
2011年 | 1286篇 |
2010年 | 914篇 |
2009年 | 882篇 |
2008年 | 1023篇 |
2007年 | 1000篇 |
2006年 | 1015篇 |
2005年 | 828篇 |
2004年 | 705篇 |
2003年 | 540篇 |
2002年 | 525篇 |
2001年 | 928篇 |
2000年 | 630篇 |
1999年 | 525篇 |
1998年 | 346篇 |
1997年 | 362篇 |
1996年 | 276篇 |
1995年 | 233篇 |
1994年 | 221篇 |
1993年 | 169篇 |
1992年 | 188篇 |
1991年 | 175篇 |
1990年 | 157篇 |
1989年 | 123篇 |
1988年 | 100篇 |
1987年 | 90篇 |
1986年 | 71篇 |
1985年 | 80篇 |
1984年 | 58篇 |
1983年 | 42篇 |
1982年 | 29篇 |
1981年 | 29篇 |
1980年 | 21篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 29篇 |
1975年 | 27篇 |
1974年 | 22篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Shilin Jiang Dr. Yalan Liu Dr. Lin Wang Prof. Zhifang Chai Prof. Wei-Qun Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(60):e202201145
The coordination chemistry of f-block elements (lanthanide and actinide) in molten salts has become a resounding topic in view of its great importance to the research and development (R&D) of molten salt reactors and pyroprocessing. In this Review article, a general overview of the coordination chemistry of f-block elements in molten salts is provided including past achievements and recent advances. Particular emphases are placed on the oxidation state, speciation, and solution structure of f-block metal ions in molten salts, as well as their relationships with the salt composition. Furthermore, this review briefly discusses the spectroscopic and theoretical methods that complement each other in revealing the coordination properties. 相似文献
2.
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
3.
4.
Su X. F. Zhang Y. L. Maximov A. L. Zhang K. Xin Q. Feng C. Q. Bai X. F. Wu W. 《Russian Journal of Applied Chemistry》2020,93(1):127-136
Russian Journal of Applied Chemistry - Nanoscale ZSM-5 (AlZ5-D) and Ga-substituted ZSM-5 zeolites ((Al,Ga)Z5-D and GaZ5-D) were synthesized by a green dry-gel conversion strategy. For comparison,... 相似文献
5.
Journal of Thermal Analysis and Calorimetry - In the present work, pyrolysis kinetic mechanism was studied for regenerated cellulosic fiber (RCF) and composite RCF containing silicon/nitrogen flame... 相似文献
6.
7.
Kinetics and Catalysis - A series of Cu-SSZ-13@CeO2 catalysts with surface modification with CeO2 was prepared by the modified self-resemble method based on the one-pot synthesized Cu-SSZ-13... 相似文献
8.
本文给出了混合型多项式Hammerstein积分方程正解的迭代求法,并将所得结果应用到二阶非线性常微分方程的边值问题 相似文献
9.
In this paper, the authors studied certain properties of the estimate of Liang and Krishnaiah (1985, J. Multivariate Anal. 16, 162–172) for multivariate binary density. An alternative shrinkage estimate is also obtained. The above results are generalized to general orthonormal systems. 相似文献
10.
A numerical procedure, with an exact strain-displacement relationship of twisted and curved cylindrical panels having variable thickness derived by considering the Green strain tensor on general shell theory, is presented using the principle of virtual work and the Rayleigh-Ritz method with algebraic polynomials as in-plane and transverse displacement functions. The accuracy and applicability of the procedure are verified by comparing the present results with previous experimental and theoretical results for several panels. The effects of variation ratio of thickness in chordwise and lengthwise directions, twist, and curvature both in two directions aforementioned on vibrations of cylindrical panels are studied in detail, and typical vibration mode shapes are plotted to demonstrate the effects. 相似文献