全文获取类型
收费全文 | 1078篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
化学 | 376篇 |
力学 | 51篇 |
数学 | 394篇 |
物理学 | 270篇 |
出版年
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2014年 | 11篇 |
2013年 | 55篇 |
2012年 | 42篇 |
2011年 | 55篇 |
2010年 | 24篇 |
2009年 | 15篇 |
2008年 | 27篇 |
2007年 | 38篇 |
2006年 | 27篇 |
2005年 | 43篇 |
2004年 | 24篇 |
2003年 | 27篇 |
2002年 | 26篇 |
2001年 | 16篇 |
2000年 | 30篇 |
1999年 | 20篇 |
1998年 | 16篇 |
1997年 | 20篇 |
1996年 | 35篇 |
1995年 | 30篇 |
1994年 | 30篇 |
1993年 | 39篇 |
1992年 | 42篇 |
1991年 | 39篇 |
1990年 | 42篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 13篇 |
1986年 | 23篇 |
1985年 | 12篇 |
1984年 | 26篇 |
1983年 | 7篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 13篇 |
1976年 | 14篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1973年 | 5篇 |
1972年 | 8篇 |
1970年 | 4篇 |
1968年 | 10篇 |
1938年 | 5篇 |
排序方式: 共有1091条查询结果,搜索用时 15 毫秒
1.
W.P. RDZANEK JR 《Journal of sound and vibration》2002,249(2):307-323
The standardized mutual active and reactive sound power of a clamped plate, representing the energy aspect of the reciprocal interactions of two different in vacuo modes, has been computed. It was assumed that the vibrations are axisymmetric, elastic and time harmonic, the plate's transverse deflection is small as compared with the plate's size, and that the vibration velocity is small as compared with the acoustic wavenumber generated. The Kirchhoff-Love theory of a perfectly elastic plate was used. The integral formulae for the mutual sound power were transformed into their Hankel representations which made possible their subsequent computation. A closed path integral was used to express the integral in its Hankel representation to compute the mutual active sound power. The asymptotic stationary phase method was used to compute the two magnitudes, i.e., the mutual active and reactive sound power. The results obtained are the asymptotic formulae valid for the acoustically fast waves. The oscillating as well as the non-oscillating terms have been identified in the formulae to make possible their further separate analysis. The availability of the asymptotic formulae makes possible some fast numerical computations of the mutual sound power. Moreover, the formulae presented herein, together with those for the individual modes known from the literature, make a complete basis for further computations of the total sound power of the plate's damped and forced vibrations in fluid. 相似文献
2.
Ajay K. Saini Clifford M. Carlin Howard H. Patterson 《Journal of polymer science. Part A, Polymer chemistry》1992,30(3):419-427
New model compounds for poly[N,N′-bis(phenoxyphenyl)pyromellitimide] have been synthesized in order to investigate the formation of imine bonds which are proposed to form during the curing process and lead to crosslinking in the bulk polymer. Raman studies show that terminal amines can react with imide carbonyls during curing to form C?N bonds. The Raman band due to C?N appears at 1656 cm?1 and the band due to C?O closest to the imine bond is observed at 1742 cm?1. These results are in agreement with previously published results on vapor deposited polyimide films. 相似文献
3.
Patterson JR Barker A Briere RA Gibbons LK Makoff G Papadimitriou V Somalwar S Wah YW Winstein B Winston R Woods M Yamamoto H Swallow E Bock GJ Coleman R Enagonio J Hsiung YB Stanfield K Stefanski R Yamanaka T Blair G Gollin GD Karlsson M Okamitsu JK Tschirhart R Brisson JC Debu P Peyaud B Turlay R Vallage B 《Physical review letters》1990,64(13):1491-1494
4.
5.
Patterson P 《OR manager》1990,6(10):1, 6-1, 7
6.
7.
Patterson P 《OR manager》1990,6(4):1, 8-1, 9
8.
9.