全文获取类型
收费全文 | 5019篇 |
免费 | 105篇 |
国内免费 | 43篇 |
专业分类
化学 | 3031篇 |
晶体学 | 46篇 |
力学 | 98篇 |
数学 | 947篇 |
物理学 | 1045篇 |
出版年
2022年 | 48篇 |
2021年 | 57篇 |
2020年 | 82篇 |
2019年 | 66篇 |
2018年 | 36篇 |
2017年 | 39篇 |
2016年 | 78篇 |
2015年 | 83篇 |
2014年 | 79篇 |
2013年 | 236篇 |
2012年 | 242篇 |
2011年 | 246篇 |
2010年 | 148篇 |
2009年 | 132篇 |
2008年 | 225篇 |
2007年 | 267篇 |
2006年 | 265篇 |
2005年 | 256篇 |
2004年 | 238篇 |
2003年 | 189篇 |
2002年 | 186篇 |
2001年 | 96篇 |
2000年 | 123篇 |
1999年 | 70篇 |
1998年 | 87篇 |
1997年 | 68篇 |
1996年 | 81篇 |
1995年 | 74篇 |
1994年 | 73篇 |
1993年 | 89篇 |
1992年 | 61篇 |
1991年 | 52篇 |
1990年 | 58篇 |
1989年 | 57篇 |
1988年 | 40篇 |
1987年 | 46篇 |
1986年 | 49篇 |
1985年 | 64篇 |
1984年 | 51篇 |
1983年 | 45篇 |
1982年 | 41篇 |
1981年 | 42篇 |
1980年 | 44篇 |
1979年 | 28篇 |
1978年 | 38篇 |
1977年 | 44篇 |
1976年 | 49篇 |
1975年 | 55篇 |
1974年 | 43篇 |
1973年 | 52篇 |
排序方式: 共有5167条查询结果,搜索用时 0 毫秒
21.
We give asymptotic formulas for the multiplicities of weights and irreducible summands in high-tensor powers Vλ⊗N of an irreducible representation Vλ of a compact connected Lie group G. The weights are allowed to depend on N, and we obtain several regimes of pointwise asymptotics, ranging from a central limit region to a large deviations region. We use a complex steepest descent method that applies to general asymptotic counting problems for lattice paths with steps in a convex polytope. 相似文献
22.
A. L'Esprance J. Nicolas D.K. Wilson D.W. Thomson Y. Gabillet G. Daigle 《Applied Acoustics》1993,40(4)
This paper presents a set of acoustical and meteorological data from an outdoor sound propagation experiment. This experiment was done in a farm field near Rock Springs, Pennsylvania, on 7 July 1990. Meteorological and acoustical measurements were recorded simultaneously during six different times in the day. The meteorological measurements permitted determination of the sound speed profiles during each of the measurement sessions, using a method based on surface-layer similarity scaling. The acoustical measurements allowed precise determination of the relative sound pressure levels for a frequency range up to 3150 Hz at six different distances (66, 88, 125, 175, 250 and 350 m). The results show atmospheric conditions have an important effect on sound propagation. At medium and high frequencies, variations of the relative SPL have been measured at distances as short as 62 m. These effects increased with the distances so that variations as great as 30 dB have been measured during that day. Comparisons with the fast field program predictions are also presented, and amply demonstrate the accuracies of this model, especially for the downward refraction cases. 相似文献
23.
24.
25.
26.
Differential oscillator strengths and dipole polarizabilities for transitions of the helium sequence
The dipole radial integral for an initial discrete 1s state and a final continuum state has been calculated under the screened hydrogenic model. In this model, single-electron hydrogenic wave functions are employed and the initial and the final states are treated by two different effective-charge parameters. Numerical values of differential oscillator strengths for transitions from 1s 21S to the continuum for the helium sequence ions are obtained. Also calculated are the dipole polarizabilities, which are found to be in excellent agreement with the results of other authors. 相似文献
27.
Bortoletto D Goldberg M Horwitz N Mestayer MD Moneti GC Sharma V Shipsey IP Skwarnicki T Csorna SE Letson T Brock IC Ferguson T Artuso M Bebek C Berkelman K Blucher E Byrd J Cassel DG Cheu E Coffman DM Crawford G DeSalvo R DeWire JW Drell PS Ehrlich R Galik RS Gittelman B Gray SW Halling AM Hartill DL Heltsley BK Kandaswamy J Kowalewski R Kreinick DL Kubota Y Lewis JD Mistry NB Mueller J Namjoshi R Nandi S Nordberg E O'Grady C Peterson D Pisharody M Riley D Sapper M Silverman A Stone S Worden H 《Physical review letters》1989,62(21):2436-2439
28.
Shaw NM Blanis D Bodek A Budd H Coombes R Eno S Fry CA Harada H Ho YH Kim YK Kumita T Mori T Olsen SL Sill A Thorndike EH Ueno K Zheng HW Imlay R Kirk P Lim J McNeil RR Metcalf W Myung SS Cheng CP Gu P Li J Li YK Mao ZP Xu YT Zhu YC Abashian A Gotow K Hu K Low EH Mattson ME Naito F Piilonen L Sterner KL Lusin S Rosenfeld C Wang AT Wilson S Frautschi M Kagan H Kass R Trahern CG Breedon RE Kim GN Ko W Lander RL Maeshima K Malchow RL Smith JR Sparks K Williams MC Abe K Fujii Y Higashi Y Kim SK 《Physical review letters》1989,63(13):1342-1345
29.
30.