全文获取类型
收费全文 | 3067篇 |
免费 | 433篇 |
国内免费 | 313篇 |
专业分类
化学 | 575篇 |
晶体学 | 40篇 |
力学 | 1385篇 |
综合类 | 51篇 |
数学 | 257篇 |
物理学 | 1505篇 |
出版年
2024年 | 9篇 |
2023年 | 14篇 |
2022年 | 64篇 |
2021年 | 74篇 |
2020年 | 100篇 |
2019年 | 82篇 |
2018年 | 59篇 |
2017年 | 112篇 |
2016年 | 124篇 |
2015年 | 114篇 |
2014年 | 145篇 |
2013年 | 206篇 |
2012年 | 140篇 |
2011年 | 185篇 |
2010年 | 129篇 |
2009年 | 169篇 |
2008年 | 194篇 |
2007年 | 190篇 |
2006年 | 170篇 |
2005年 | 172篇 |
2004年 | 167篇 |
2003年 | 163篇 |
2002年 | 126篇 |
2001年 | 115篇 |
2000年 | 105篇 |
1999年 | 110篇 |
1998年 | 85篇 |
1997年 | 66篇 |
1996年 | 64篇 |
1995年 | 45篇 |
1994年 | 56篇 |
1993年 | 36篇 |
1992年 | 30篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 25篇 |
1988年 | 27篇 |
1987年 | 17篇 |
1986年 | 20篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1957年 | 1篇 |
排序方式: 共有3813条查询结果,搜索用时 203 毫秒
991.
992.
M. Castrillón López 《Reports on Mathematical Physics》2003,52(3):423-435
Let λ : U(1) → GL (V) be a linear representation. Lagrangians defined on J1(T*M × V)whose universal current form is gauge invariant, are described in terms of gauge invariant Lagrangians and invariant functions on V. A characterization of gauge invariant Lagrangians depending on matter fields only, that is, L : J1V → ?, is also obtained. 相似文献
993.
994.
Dong-Won Kim Nak-Kyu Lee Kyoung-Hoan Na Dongil Kwon 《Optics and Lasers in Engineering》2005,43(2):221-232
We used electronic speckle pattern interferometry (ESPI) to measure in situ displacement fields nondestructively and with high resolution (10−2 μm) by using the interferometry principle and the phase-shift technique. We measured the depth profile of the residual stress in steel pipe manufactured by thermomechanically controlled processing using a quantitative model, which explains the relationship between residual stress and displacement measured by ESPI in chemical etching. We analyzed the variation of yield stresses measured by the indentation technique and the residual stresses at various depths. The relationship between the residual stresses and the yield stresses was consistent with simulated results and can be used for indirect evaluation of the residual stresses from the yield stresses. 相似文献
995.
R. G. Yakupov 《Journal of Applied Mechanics and Technical Physics》2008,49(2):306-312
Wave processes in a semi-infinite rod located in an elastic medium under pulsed loading by an external distributed force are
considered. A system of two differential equations of motion of Timoshenko’s beam theory is solved with the use of the Laplace
transform in time. The resultant integrals are determined numerically. The changes in bending and bending moment over the
longitudinal coordinate at different times are demonstrated.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 2, pp. 178–184, March–April, 2008. 相似文献
996.
The first part of the paper deals with homogenization models of unidirectional composites, in which each phase of the material
is bounded by parallel cylindrical surfaces. For a GFRP with epoxy resin and glass fibres, five elastic constants for six
models of the composite are calculated. In the second part, the results of strain gauge tests, photoelasticity investigations,
and scanning electron inspection are discussed. With these data, some elastic constants of the composite in tension and compression
are found. A comparison of experimental and analytical results is presented.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 2, pp. 195–206, March–April, 2008. 相似文献
997.
HWANG Keh-Chih 《中国科学G辑(英文版)》2009,52(9):1375-1381
The flow theory of mechanism-based strain gradient plasticity theory (MSG) developed by Qiu et al. (2003) is extended for
incompressible material. The MSG flow theory is used to predict the increase of plastic work hardening for plane strain tension
of surface-passivated Cu thin film. The theoretical predictions agree well with experiments for suitably chosen material parameters.
Contributed by HWANG Keh-Chih 相似文献
998.
An exotic class of nonlinear p-form non-Abelian gauge theories is studied, arising from the most general allowed covariant deformation of linear Abelian gauge theory for a set of massless 1-form fields and 2-form fields in four dimensions. These theories combine a Chapline–Manton type coupling of the 1-forms and 2-forms, along with a Yang–Mills coupling of the 1-forms, a Freedman–Townsend coupling of the 2-forms, and an extended Freedman–Townsend type coupling between the 1-forms and 2-forms. It is shown that the resulting theories have a geometrically interesting dual formulation that is equivalent to an exotic Yang–Mills dilaton theory involving a nonlinear sigma field. In particular, the nonlinear sigma field couples to the Yang–Mills 1-form field through a generalized Chern class 4-form term. 相似文献
999.
1000.
采用多种X射线衍射技术和磁电阻测量技术研究了不同厚度的La0.8Ca0.2MnO3/SrTiO3 (LCMO/STO)薄膜的应变状态及其对磁电阻性能的影响.结果表明,在STO(001)单晶衬底上生长的LCMO薄膜沿[00l]取向生长.LCMO薄膜具有伪立方钙钛矿结构,随着薄膜厚度的增加,面内晶格参数增加,垂直于面内的晶格参数减小,晶格参数a和b相近,略小于c.LC
关键词:
X射线衍射
微结构
应变
物理性能 相似文献