全文获取类型
收费全文 | 163920篇 |
免费 | 1845篇 |
国内免费 | 402篇 |
专业分类
化学 | 89867篇 |
晶体学 | 2455篇 |
力学 | 6389篇 |
综合类 | 3篇 |
数学 | 15899篇 |
物理学 | 51554篇 |
出版年
2021年 | 1172篇 |
2020年 | 1386篇 |
2019年 | 1394篇 |
2018年 | 1808篇 |
2017年 | 1857篇 |
2016年 | 2968篇 |
2015年 | 1937篇 |
2014年 | 2727篇 |
2013年 | 6766篇 |
2012年 | 5551篇 |
2011年 | 6798篇 |
2010年 | 4574篇 |
2009年 | 4556篇 |
2008年 | 6490篇 |
2007年 | 6225篇 |
2006年 | 6075篇 |
2005年 | 5538篇 |
2004年 | 4900篇 |
2003年 | 4546篇 |
2002年 | 4396篇 |
2001年 | 5869篇 |
2000年 | 4248篇 |
1999年 | 3316篇 |
1998年 | 2309篇 |
1997年 | 2409篇 |
1996年 | 2305篇 |
1995年 | 2146篇 |
1994年 | 2111篇 |
1993年 | 1964篇 |
1992年 | 2467篇 |
1991年 | 2491篇 |
1990年 | 2297篇 |
1989年 | 2257篇 |
1988年 | 2220篇 |
1987年 | 2265篇 |
1986年 | 2089篇 |
1985年 | 2588篇 |
1984年 | 2609篇 |
1983年 | 2106篇 |
1982年 | 2110篇 |
1981年 | 1982篇 |
1980年 | 1932篇 |
1979年 | 2206篇 |
1978年 | 2310篇 |
1977年 | 2235篇 |
1976年 | 2140篇 |
1975年 | 2034篇 |
1974年 | 1987篇 |
1973年 | 2022篇 |
1972年 | 1312篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
U. Kreibig K. Fauth M. Quinten D. Schönauer 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,12(1-4):505-514
First, some general remarks concerning macroscopic “cluster matter” are given. In the second part, three recent, mainly optically and electron-microscopically performed investigations are discussed which deal with special properties of noble metal cluster systems forming the building units of this kind of matter:(1) dressed Au-55 clusters,(2) electromagnetic coupling effects among coagulated clusters,(3) the transition towards compact inhomogeneous matter caused by coalescence of clusters. 相似文献
992.
993.
994.
995.
T. Yu. Samgina P. A. Sharbatyan L. S. Shishkanova N. A. Andronova A. I. Pavlyuchenko V. V. Titov 《Chemistry of Heterocyclic Compounds》1987,23(11):1207-1211
The basic principles of the mass-spectral fragmentation of arylalkylpyridines that contain substituents in various positions were established. The principle ions that can be used in Chromatographic mass-fragmentographic analysis in the study of liquid-crystal compositions were determined for each specific case.Communication 1 of the series Mass spectra of liquid crystalsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1509–1513, November, 1987. 相似文献
996.
Y. Sakaiguchi T. Shikata H. Urakami A. Tamura H. Hirata 《Colloid and polymer science》1987,265(8):750-753
Some cationic surfactants such as cetyltrimethylammonium bromide (CTAB) show a very spectacular viscoelasticity in solution, in even very diluted states, with some aromatic substances added, such as salicylic acid. Formerly, the authors established that the remarkable solution behaviour was the result of the entanglement of such enormously elongated giant micelles, based on recognition of the existence of large aggregates, through direct observation of them as substantial images under the electron microscope.In this report, we further confirm the relation between micelle length and solution viscoelasticity after arbitrarily obtaining different size aggregates by altering the media pH, or by admixing shorter chain length surfactants than CTAB, which alone did not induce viscoelasticity. 相似文献
997.
Conclusions Pronounced synergism of the asymmetric effect of chiral copper-palladium catalysts related to manifestation of a ligand effect was found.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 277–280, February, 1987. 相似文献
998.
T. P. Pogrebnaya V. G. Solomonik V. N. Vinogradova M. I. Godneva 《Theoretical and Experimental Chemistry》1987,22(6):693-697
The geometric structure, force fields, and vibrational spectra of M2O and MOH (M=Li, Na) molecules have been investigated. The size of the d basis on the oxygen atom has a significant influence only on the frequency of the deformation vibration 3. Experimentally unknown constants of the molecules considered have been evaluated.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 6, pp. 724–728, November–December, 1986. 相似文献
999.
1000.