全文获取类型
收费全文 | 3213篇 |
免费 | 44篇 |
国内免费 | 12篇 |
专业分类
化学 | 2124篇 |
晶体学 | 25篇 |
力学 | 94篇 |
数学 | 387篇 |
物理学 | 639篇 |
出版年
2022年 | 22篇 |
2021年 | 32篇 |
2019年 | 25篇 |
2016年 | 35篇 |
2015年 | 31篇 |
2014年 | 43篇 |
2013年 | 144篇 |
2012年 | 117篇 |
2011年 | 145篇 |
2010年 | 57篇 |
2009年 | 66篇 |
2008年 | 142篇 |
2007年 | 161篇 |
2006年 | 138篇 |
2005年 | 129篇 |
2004年 | 134篇 |
2003年 | 134篇 |
2002年 | 132篇 |
2001年 | 93篇 |
2000年 | 72篇 |
1999年 | 40篇 |
1998年 | 45篇 |
1997年 | 46篇 |
1996年 | 51篇 |
1995年 | 61篇 |
1994年 | 49篇 |
1993年 | 55篇 |
1992年 | 43篇 |
1991年 | 59篇 |
1990年 | 53篇 |
1989年 | 27篇 |
1988年 | 33篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 42篇 |
1984年 | 53篇 |
1983年 | 33篇 |
1982年 | 42篇 |
1981年 | 46篇 |
1980年 | 37篇 |
1979年 | 37篇 |
1978年 | 53篇 |
1977年 | 45篇 |
1976年 | 36篇 |
1975年 | 34篇 |
1974年 | 27篇 |
1973年 | 49篇 |
1972年 | 30篇 |
1971年 | 24篇 |
1969年 | 20篇 |
排序方式: 共有3269条查询结果,搜索用时 15 毫秒
11.
Nathalie Charton Achim Feldermann Alexander Theis Martina H. Stenzel Thomas P. Davis Christopher Barner‐Kowollik 《Journal of polymer science. Part A, Polymer chemistry》2004,42(21):5559-5559
The original article to which this Erratum refers was published in J Polym Sci Part A: Polym Chem (2004) 42(20) 5170–5179. No abstract. 相似文献
12.
Hydrogenated amorphous GaP films have been prepared by reactive rf sputtering. Infrared spectroscopy, optical transmission and reflection, photothermal deflection spectroscopy and dc conductivity have been studied to investigate the local bonding configurations, the optical absorption edges and the temperature dependence of the conductivity as a function of hydrogen content. The results are discussed and compared with the effects of hydrogenation on amorphous Si. 相似文献
13.
J. Pollanen K.R. Shirer S. Blinstein J.P. Davis H. Choi T.M. Lippman W.P. Halperin L.B. Lurio 《Journal of Non》2008,354(40-41):4668-4674
We discuss two methods by which high porosity silica aerogels can be engineered to exhibit global anisotropy. First, anisotropy can be introduced with axial strain (i.e. axial compression). In addition, intrinsic anisotropy can result during growth and drying stages and, suitably controlled, it can be correlated with preferential radial shrinkage in cylindrical samples. We have performed small angle X-ray scattering (SAXS) to characterize these two types of anisotropy. We show that global anisotropy originating from either strain or shrinkage leads to optical birefringence and that optical cross-polarization studies are a useful characterization of the uniformity of the imposed global anisotropy. 相似文献
14.
15.
Davis J. Clark R.W. Giuliani J.L. Jr. Thornhill J.W. Deeney C. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1998,26(4):1192-1201
In this paper, we study the dynamics of a massive aluminum Z-pinch plasma load and evaluate its performance as a soft X-ray radiator. A radiation hydrodynamic model self-consistently driven by a circuit describes the dynamics. Comparisons are made for the K- and L-shell soft X-ray emission as a function of the ionization dynamic model. The ionization dynamic models are represented by: 1) a time-dependent nonequilibrium (NEQ) model, 2) a collisional radiative equilibrium (CRE) model, and 3) a local thermodynamic equilibrium (LTE) model. For all three scenarios the radiation is treated 1) in the free streaming optically thin approximation where the plasma is treated as a volume emitter and 2) in the optically thick regime where the opacity for the lines and continuum is self-consistently calculated online and the radiation is transported through the plasma. Each simulation is carried out independently to determine the sensitivity of the implosion dynamics to the ionization and radiation model, i.e., how the ionization dynamic model affects the radiative yield and emission spectra. Results are presented for the L- and K-shell radiation yields and emission spectra as a function of photon energy from 10 eV to 10 keV. Also, departure coefficients from LTE are presented for selected levels and ionization stages 相似文献
16.
Davis RL 《Physical review D: Particles and fields》1989,40(12):4033-4036
17.
18.
19.
20.