全文获取类型
收费全文 | 424074篇 |
免费 | 3178篇 |
国内免费 | 1018篇 |
专业分类
化学 | 220754篇 |
晶体学 | 6805篇 |
力学 | 20673篇 |
综合类 | 18篇 |
数学 | 49067篇 |
物理学 | 130953篇 |
出版年
2020年 | 3598篇 |
2019年 | 4244篇 |
2018年 | 5918篇 |
2017年 | 5946篇 |
2016年 | 8260篇 |
2015年 | 4536篇 |
2014年 | 7675篇 |
2013年 | 17595篇 |
2012年 | 13397篇 |
2011年 | 16178篇 |
2010年 | 12082篇 |
2009年 | 12025篇 |
2008年 | 15182篇 |
2007年 | 15316篇 |
2006年 | 13928篇 |
2005年 | 12490篇 |
2004年 | 11673篇 |
2003年 | 10606篇 |
2002年 | 10504篇 |
2001年 | 11582篇 |
2000年 | 8848篇 |
1999年 | 6831篇 |
1998年 | 5943篇 |
1997年 | 6023篇 |
1996年 | 5557篇 |
1995年 | 5074篇 |
1994年 | 5277篇 |
1993年 | 4959篇 |
1992年 | 5651篇 |
1991年 | 5694篇 |
1990年 | 5558篇 |
1989年 | 5472篇 |
1988年 | 5499篇 |
1987年 | 5383篇 |
1986年 | 5135篇 |
1985年 | 6716篇 |
1984年 | 7057篇 |
1983年 | 5880篇 |
1982年 | 5949篇 |
1981年 | 5876篇 |
1980年 | 5660篇 |
1979年 | 5936篇 |
1978年 | 6231篇 |
1977年 | 6291篇 |
1976年 | 6316篇 |
1975年 | 5863篇 |
1974年 | 5872篇 |
1973年 | 6117篇 |
1972年 | 4424篇 |
1971年 | 3860篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of the Ukraine. Translated from Prikladnaya Mekhanika, Vol. 31, No. 9, pp. 15–23, September, 1995. 相似文献
992.
E.P. Yelsukov Yu.N. Vorobyov T.I. Arbusova I.B. Smolyak 《Journal of magnetism and magnetic materials》1994,130(1-3):44-50
We have measured the concentration dependence of the average magnetic moment per Fe atom
Fe(x) in microcrystalline and amorphous Fe-P alloys obtained over a wide concentration range using electrochemical deposition. The model of local magnetic moments has been used to described
Fe(x). On the basis of this model the effects of phosphorus on the value
Fe are explained in terms of the parameters of the local environment of the Fe atom. 相似文献
993.
L Jirovetz G Buchbauer W J?ger A Woidich A Nikiforov 《Biomedical chromatography : BMC》1992,6(3):133-134
After inhalation experiments with sandalwood oil and the pure fragrance compounds coumarin and alpha-terpineol, substances were detected and measured in the blood samples of test animals (mice) using gas chromatography/mass spectrometry (GC/MS) (MID) in connection with GC/FTIR (SWC), GC/AES (carbon and oxygen trace) and flame ionization detection/gas chromatography. Using tiglinic acid benzyl ester as the internal standard the following concentrations in serum could be found: alpha-santalol 6.1 ng/mL, beta-santalol 5.3 ng/mL and alpha-santalene 0.5 ng/mL. In separate inhalation experiments with coumarin and with alpha-terpineol the corresponding concentrations were 7.7 ng/mL and 6.9 ng/mL, respectively. 相似文献
994.
Middle-ear phenomenology: the view from the three windows. 总被引:1,自引:0,他引:1
995.
996.
997.
S. A. Chernyak O. V. Shekhter N. L. Sergovskaya Yu. S. Tsizin 《Chemistry of Heterocyclic Compounds》1992,28(7):832-834
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 994–996, July, 1992. 相似文献
998.
Brush S.G. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(6):577-589
Hannes Alfven's research program in solar system physics provides a valuable case study for the historians and philosophers of science. The response of the scientific community to his remarkable contributions is a severe test of widely held views about how science is or should be done. Seven of those contributions are examined, in the light of two doctrines of scientific methodology, those of Karl Popper (1959) and Imre Lakatos (1978). The seven are: application of the magnetic braking concept to the origin of the solar system; magnetohydrodynamic waves; field-aligned (`Birkeland') currents; critical ionization velocity and the existence of planetary rings; jet streams; electrostatic double layers; and partial corotation 相似文献
999.
1000.
Dumbrajs O. Nuisnovich G.S. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(4):452-457
A theory is presented which describes the dependence of the multimode operation of a gyrotron on the modulation and beam voltages. Nonlinear nonstationary processes are considered. An approximate start-up scenario of a gyrotron is determined which makes it possible to achieve single-mode excitation and high-efficiency operation in a desired mode, as well as to switch the tube to a similar operation in other modes 相似文献