全文获取类型
收费全文 | 2111篇 |
免费 | 46篇 |
国内免费 | 10篇 |
专业分类
化学 | 1615篇 |
晶体学 | 21篇 |
力学 | 13篇 |
数学 | 150篇 |
物理学 | 368篇 |
出版年
2021年 | 11篇 |
2020年 | 20篇 |
2019年 | 17篇 |
2018年 | 19篇 |
2017年 | 25篇 |
2016年 | 32篇 |
2015年 | 32篇 |
2014年 | 40篇 |
2013年 | 84篇 |
2012年 | 72篇 |
2011年 | 118篇 |
2010年 | 65篇 |
2009年 | 72篇 |
2008年 | 99篇 |
2007年 | 110篇 |
2006年 | 110篇 |
2005年 | 97篇 |
2004年 | 105篇 |
2003年 | 96篇 |
2002年 | 78篇 |
2001年 | 41篇 |
2000年 | 37篇 |
1999年 | 42篇 |
1998年 | 19篇 |
1997年 | 55篇 |
1996年 | 27篇 |
1995年 | 17篇 |
1994年 | 27篇 |
1993年 | 34篇 |
1992年 | 35篇 |
1991年 | 20篇 |
1990年 | 29篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1987年 | 23篇 |
1986年 | 19篇 |
1985年 | 36篇 |
1984年 | 32篇 |
1983年 | 21篇 |
1982年 | 26篇 |
1981年 | 23篇 |
1980年 | 37篇 |
1979年 | 47篇 |
1978年 | 26篇 |
1977年 | 25篇 |
1976年 | 28篇 |
1975年 | 16篇 |
1974年 | 15篇 |
1973年 | 12篇 |
1972年 | 10篇 |
排序方式: 共有2167条查询结果,搜索用时 15 毫秒
141.
Yutaka Kojima 《Physica A》1979,95(1):162-168
A re-evaluation is given of the temperature dependent term in the first order exchange contribution to the grand partition function for an electron gas. The existence and origin of the logarithmic term in the temperature-dependent part are shown in a very simple manner. 相似文献
142.
143.
Yasuto Uchio Junzo Toyota Hiroshi Nozaki Mitsuru Nakayama Yoshifumi Nishizono Tsunao Hase 《Tetrahedron letters》1981,22(41):4089-4092
The structures of lobohedleolide (1) and (7Z)-lobohedleolide (2), two new cembranolides containing the α,β-unsaturated carboxylic acid system isolated from the Japanese soft coral Lobophytum hedleyi Whitelegge, were elucidated from spectral and chemical evidence, and the absolute configuration of (1) was determined by X-ray analysis of its p-bromophenacyl ester (9). Lobohedleolide (1) showed growth inhibition of the in vitro Hella cells. 相似文献
144.
Electrostatic ion cyclotron waves in the presence of light minority-species ions are experimentally investigated. The observations reveal that already a small fraction (~1%) of the minority concentratios leads to a new cutoff and resonance near the minority-cyclotron-resonance frequency. 相似文献
145.
Yukiji Shimojima Hiroshi Hayashi Tadaaki Ooka Mitsuru Shibukawa Yoichi Iitaka 《Tetrahedron letters》1982,23(51):5435-5438
The structures of a novel gastroprotective substance AI-77-B and its analogues AI-77-C, D, F and G, which are produced by Bacillus pumilus, are described. Five of the asymmetric centers of AI-77-B have S absolute stereochemistry confirmed by X-ray in combination with chemical studies. 相似文献
146.
147.
Yoshio Teki Takeji Takui Mitsuru Hirai Koichi Itoh Hiizu Iwamura 《Chemical physics letters》1982,89(3):263-267
Optically detected ENDOR and electron—nuclear—nuclear triple resonance of 17O were measured via phosphorescence from 3(nπ*) benzil in benzophenone-d10 crystals at high magnetic field. The n and π* spin densities on the oxygen atom are 0.201 and 0.092, respectively, the angle between the two CO bonds being 150°. 相似文献
148.
149.
150.
Cho T Yoshida M Kohagura J Hirata M Numakura T Higaki H Hojo H Ichimura M Ishii K Islam KM Itakura A Katanuma I Nakashima Y Saito T Tatematsu Y Yoshikawa M Kojima Y Tokioka S Yokoyama N Tomii Y Imai T Pastukhov VP Miyoshi S;GAMMA Group 《Physical review letters》2005,94(8):085002
Vortexlike turbulent structures in hot-ion mode plasmas with several keV are observed in the case with a radially produced weak shear of electric fields E(r). However, a strong E(r) shear formation due to a high ion-confining potential phi(c) production clears up these vortices together with plasma-confinement improvement and disappearance of both drift-wave and turbulencelike Fourier spectral signals. These findings are based on three-time progress in phi(c) in comparison to phi(c) attained 1992-2002. The significant advance of phi(c) is well extended in line with proposed potential-formation physics scalings. 相似文献