全文获取类型
收费全文 | 2983篇 |
免费 | 342篇 |
国内免费 | 277篇 |
专业分类
化学 | 831篇 |
晶体学 | 8篇 |
力学 | 845篇 |
综合类 | 45篇 |
数学 | 782篇 |
物理学 | 1091篇 |
出版年
2024年 | 4篇 |
2023年 | 33篇 |
2022年 | 55篇 |
2021年 | 63篇 |
2020年 | 67篇 |
2019年 | 69篇 |
2018年 | 68篇 |
2017年 | 89篇 |
2016年 | 86篇 |
2015年 | 106篇 |
2014年 | 151篇 |
2013年 | 180篇 |
2012年 | 178篇 |
2011年 | 164篇 |
2010年 | 133篇 |
2009年 | 144篇 |
2008年 | 130篇 |
2007年 | 178篇 |
2006年 | 167篇 |
2005年 | 164篇 |
2004年 | 138篇 |
2003年 | 142篇 |
2002年 | 140篇 |
2001年 | 105篇 |
2000年 | 113篇 |
1999年 | 105篇 |
1998年 | 89篇 |
1997年 | 83篇 |
1996年 | 63篇 |
1995年 | 64篇 |
1994年 | 57篇 |
1993年 | 47篇 |
1992年 | 31篇 |
1991年 | 38篇 |
1990年 | 27篇 |
1989年 | 24篇 |
1988年 | 26篇 |
1987年 | 14篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1974年 | 2篇 |
1969年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有3602条查询结果,搜索用时 15 毫秒
1.
就标准厚度卡片在霍尔传感器的定标方面的应用作了有益的探讨。在纵向测量微小长度时,霍尔片处于磁场边缘位置,其对磁场的梯度更大,即灵敏度更高,且靠中心位置的线性更好。 相似文献
2.
3.
4.
R. J. Saykally K. M. Evenson D. A. Jennings L. R. Zink A. Scalabrin 《International Journal of Infrared and Millimeter Waves》1987,8(6):653-662
Twenty new cw FIR laser lines in CD3OH, optically pumped by a CO2 laser, are reported. The frequencies of 39 of the stronger laser lines were measured relative to stabilized CO2 lasers with a fractional uncertainty, as determined by the reproducibility of the FIR frequency itself, of 2 parts in 107.Contribution of the U.S. Government, not subject to copyright. 相似文献
5.
HUA Jianjun LIU Yanhong & ZHANG Zhihe . Institute of Physics Chinese Academy of Sciences Beijing China . College of Biomedical Engineering Capital University of Medical Sciences Beijing China Correspondence should be addressed to Hua Jianjun 《中国科学G辑(英文版)》2004,(1)
Adustyplasmacanbedefinedasacomplicatedplasmacontainingsmallsolidmattercalleddustgrainsordustparticles,whichareusuallychargednegatively,duetoelectronshighermobilitythanion,bycollectingelectronsandionsfromthebackgroundplasma.Theuniverseisfilledwithdustyplasmassuchasplanetaryrings,comettails,andnebulae.Also,inindustrialplasmaprocessing,particulatessuspendedinplasmaarethemajorcontaminationinsemiconductormanufacture.Studiesondustyplasmahavebeenextendedtofar-flungtopicssuchaswaves,instabilities,stro… 相似文献
6.
A one-dimensional bulk reaction model for the oxidation of nickeltitanium is formulated, with preferential oxidation of titaniumbeing included. The modelling is directed at the better understandingof the dominant mechanisms involved in the oxidation processand their significance for the biocompatibility of the alloy.Two different regimes for the relative diffusivities of oxygenand the metals are investigated. By assuming fast bulk reactions,different asymptotic structures emerge in different parameterregimes and the resulting models take the form of moving boundaryproblems. Different profiles of nickel concentration are obtained:in particular a nickel-rich layer (observed in practice) ispresent below the oxide/metal interface for the case when oxygenand the metals diffuse at comparable rates. 相似文献
7.
8.
We investigate the effects of adding uniformity requirements to concepts in computable structure theory such as computable categoricity (of a structure) and intrinsic computability (of a relation on a computable structure). We consider and compare two different notions of uniformity, previously studied by Kudinov and by Ventsov. We discuss some of their results and establish new ones, while also exploring the connections with the relative computable structure theory of Ash, Knight, Manasse, and Slaman and Chisholm and with previous work of Ash, Knight, and Slaman on uniformity in a general computable structure-theoretical setting. 相似文献
9.
10.
We investigate a new interpretation for the Navier-Stokes corrections to the hydrodynamic equation of asymmetric interacting particle systems. We consider a system that starts from a measure associated with a profile that is constant along the drift direction. We show that under diffusive scaling the macroscopic behavior of the process is described by a nonlinear parabolic equation whose diffusion coefficient coincides with the diffusion coefficient of the hydrodynamic equation of the symmetric version of the process. 相似文献