全文获取类型
收费全文 | 15868篇 |
免费 | 2574篇 |
国内免费 | 2166篇 |
专业分类
化学 | 7619篇 |
晶体学 | 263篇 |
力学 | 741篇 |
综合类 | 141篇 |
数学 | 1503篇 |
物理学 | 10341篇 |
出版年
2024年 | 27篇 |
2023年 | 125篇 |
2022年 | 323篇 |
2021年 | 420篇 |
2020年 | 397篇 |
2019年 | 374篇 |
2018年 | 375篇 |
2017年 | 537篇 |
2016年 | 566篇 |
2015年 | 557篇 |
2014年 | 800篇 |
2013年 | 1248篇 |
2012年 | 1110篇 |
2011年 | 929篇 |
2010年 | 822篇 |
2009年 | 1013篇 |
2008年 | 1095篇 |
2007年 | 1199篇 |
2006年 | 1019篇 |
2005年 | 981篇 |
2004年 | 817篇 |
2003年 | 766篇 |
2002年 | 653篇 |
2001年 | 536篇 |
2000年 | 545篇 |
1999年 | 507篇 |
1998年 | 430篇 |
1997年 | 426篇 |
1996年 | 350篇 |
1995年 | 271篇 |
1994年 | 244篇 |
1993年 | 220篇 |
1992年 | 186篇 |
1991年 | 163篇 |
1990年 | 106篇 |
1989年 | 107篇 |
1988年 | 83篇 |
1987年 | 47篇 |
1986年 | 41篇 |
1985年 | 31篇 |
1984年 | 32篇 |
1983年 | 9篇 |
1982年 | 28篇 |
1981年 | 16篇 |
1980年 | 12篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1974年 | 8篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
51.
52.
53.
Two-Layered Poly-o-phenylenediamine/Polyaniline Composite: Electrosynthesis and Spectroelectrochemical Properties 总被引:1,自引:0,他引:1
E. Yu. Pisarevskaya E. V. Ovsyannikova N. M. Alpatova 《Russian Journal of Electrochemistry》2004,40(9):969-976
Spectroelectrochemical properties of poly-o-phenylenediamine (PPD) and the synthesized composite of PPD and polyaniline—two chemically related polymers containing an amino-substituted benzene ring but having different conduction nature—are studied. The polyaniline synthesis on PPD-modified electrodes involves stages of the reaction initiation, the copolymer formation, and the formation of a polyaniline layer at the copolymer/solution interface. 相似文献
54.
55.
56.
胡迪鹤 《数学物理学报(B辑英文版)》2005,25(1):23-29
This paper is a continuation of [8]. In Section 1, three kinds of communication are introdnced for two states and the relations among them are investigated. In Section 2, two kinds of period of a state are introdnced and it is obtained that the period is a “class property” ,i.e. two states x and y belong to same class implies the period of x is equal to the period of y. 相似文献
57.
T. K. Solovykh 《Journal of Applied Spectroscopy》1997,64(5):654-657
The role of impurity ions in formation of the optical properties of rare-earth orthoferrites is investigated. Optical spectra
of the substituted against unsubstituted orthoferrites are presented. The influence of different isovalent substitutions on
the optical absorption of orthoferrites that are promising for magnetooptics is studied.
Institute of Solid-State and Semiconductor Physics of the Academy of Sciences of Belarus, 17, P. Brovka St., Minsk, 220072,
Belarus. Translated from zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 642–645, September–October, 1997. 相似文献
58.
We show that an electron confined to a single finite parabolic quantum well in crossed electric and magnetic fields can behave as a double quantum well system. The magnetic field is parallel to the heterostructure layers and the electric field is perpendicular to those. For a suitable choice of both fields and quantum well width, the electron can be confined to a double quantum well effective potential that is very similar to the electronic potential model for diatomic molecules. The double quantum well spectrum is calculated using a numerical algorithm based on semiclassical methods. A physical interpretation of this quantum system is given based on the analogy to the electrons bound to diatomic molecules. 相似文献
59.
A complete study of the spectrum of a finite-dimensional Bose operator is carried out in the paper. The cases in which the
spectrum is discrete or continuous are studied.
Translated fromMatematicheskie Zametki, Vol. 61, No. 6, pp. 835–854, June, 1997.
Translated by A. M. Chebotarev 相似文献
60.