全文获取类型
收费全文 | 4746篇 |
免费 | 90篇 |
国内免费 | 17篇 |
专业分类
化学 | 3400篇 |
晶体学 | 48篇 |
力学 | 77篇 |
数学 | 274篇 |
物理学 | 1054篇 |
出版年
2023年 | 22篇 |
2022年 | 25篇 |
2021年 | 31篇 |
2020年 | 61篇 |
2019年 | 56篇 |
2018年 | 53篇 |
2017年 | 33篇 |
2016年 | 73篇 |
2015年 | 71篇 |
2014年 | 93篇 |
2013年 | 216篇 |
2012年 | 209篇 |
2011年 | 275篇 |
2010年 | 161篇 |
2009年 | 173篇 |
2008年 | 238篇 |
2007年 | 272篇 |
2006年 | 267篇 |
2005年 | 200篇 |
2004年 | 183篇 |
2003年 | 184篇 |
2002年 | 190篇 |
2001年 | 121篇 |
2000年 | 144篇 |
1999年 | 92篇 |
1998年 | 65篇 |
1997年 | 64篇 |
1996年 | 54篇 |
1995年 | 50篇 |
1994年 | 58篇 |
1993年 | 66篇 |
1992年 | 56篇 |
1991年 | 57篇 |
1990年 | 52篇 |
1989年 | 56篇 |
1988年 | 54篇 |
1987年 | 45篇 |
1986年 | 41篇 |
1985年 | 66篇 |
1984年 | 63篇 |
1983年 | 59篇 |
1982年 | 56篇 |
1981年 | 38篇 |
1980年 | 40篇 |
1979年 | 63篇 |
1978年 | 45篇 |
1977年 | 49篇 |
1976年 | 19篇 |
1975年 | 29篇 |
1974年 | 35篇 |
排序方式: 共有4853条查询结果,搜索用时 0 毫秒
991.
Toshiyuki Taniuchi Hiroshi Kumigashira Masato Kubota Takanori Wakita Takanori Yokoya Kanta Ono Masaharu Oshima Mikk Lippmaa Hideomi Koinuma 《Surface science》2007,601(20):4690-4693
We have used photoelectron emission microscopy (PEEM) and X-ray magnetic circular dichroism (XMCD) to study the effect of thin film thickness on the magnetic domain formation in La0.6Sr0.4MnO3 samples that were epitaxially grown on stepped SrTiO3 (0 0 1) substrates. The magnetic image exhibited a stripe structure elongated along the step direction, irrespective of film thickness, suggesting that uniaxial magnetic anisotropy induced by step-and-terrace structures plays an important role in the magnetic domain formation. Additional domains evolved gradually with increasing film thickness. In these domains, the direction of magnetization differed from the step direction due to biaxial magneto-crystalline anisotropy. The evolution of additional magnetic domains with increasing film thickness implies that a competition exists between the two anisotropies in LSMO films. 相似文献
992.
993.
994.
Isao Akiyama Masaya Ogawa Keiichi Takase Toshiyuki Takamuku Toshio Yamaguchi Norikazu Ohtori 《Journal of solution chemistry》2004,33(6-7):797-809
Molecular dynamics (MD) simulations and X-ray scattering experiments have been carried out on liquid 1-propanol. The radial distribution functions obtained from these two methods were in good agreement with each other. On the basis of the hydrogen-bond number and the angular correlation functions of the four sequentially hydrogen-bonded O atoms derived from the MD calculation, it was found that the hydrogen-bonded O atoms preferentially form a planar zigzag chain structure, but that the plane undulates like a wave. 相似文献
995.
H. Iwasaki T. Motobayashi H. Sakurai K. Yoneda T. Gomi N. Aoi N. Fukuda Zs. Fülp U. Futakami Z. Gacsi Y. Higurashi N. Imai N. Iwasa T. Kubo M. Kunibu M. Kurokawa Z. Liu T. Minemura A. Saito M. Serata S. Shimoura S. Takeuchi Y.X. Watanabe K. Yamada Y. Yanagisawa M. Ishihara 《Physics letters. [Part B]》2005,620(3-4):118-124
The excitation of the neutron-rich nucleus 28Ne has been investigated via heavy-ion inelastic scattering in reversed kinematics. The value was determined to be , which is smaller than expected from the low excitation energy of the first state. A comparison with theoretical predictions suggests that the suppressed collectivity in 28Ne is characteristic of nuclei lying on the boundary of the ‘island of inversion’. 相似文献
996.
T. Watanabe M. Miyagi S. Schrunder T. Ertl G. Müller L Beerstecher 《Optics & Laser Technology》1995,27(6):389-391
A maximum energy of 1.6 J at 5 pps of Er:YAG laser light has been transmitted through a flexible ZnS-coated silver hollow waveguide which has an inner diameter of 800 μm and is 116 cm long. The straight waveguide loss is 0.6 dB m−1 and no significant loss and mechanical changes have been found after an endurance test of 10000 pulse transmissions and bending 400 times with a bending radius of 30 cm. 相似文献
997.
Toshiyuki Katsura Yuji Shimizu Kenji Ueno 《Communications in Mathematical Physics》1989,121(4):603-627
New formulation of bosonization is given so that it is defined over the ring Z of integers. The charge zero sector of the new boson Fock space is the completion of the coordinate ring of the universal Witt scheme. By using new bosonization, conformal field theory of free fermions over Z is given.Dedicated to Professor M. Sato on his sixtieth birthdayPartially supported by Max-Planck-Institut für MathematikPartially supported by Max-Planck-Institut für Mathematik 相似文献
998.
999.
M. Watanabe A. Endoh N. Sarukura S. Watanabe 《Applied physics. B, Lasers and optics》1989,48(5):417-420
A 180-fs UV pulse has been generated based on a hybrid synchronously pumped mode-locked dye laser for a multiterawatt KrF laser system. The pulse width was measured by the single shot autocorrelation technique with the three-photon fluorescence of the XeF C-A transition. The pulse width broadening due to dispersive media was investigated. The results show that the observed pulse width broadening from 210 fs to 390 fs through the entire system is explained mostly by the linear dispersion of the optical elements for near-transform-limited input pulses. 相似文献
1000.
H. Imajo K. Hayasaka R. Ohmukai M. Watanabe S. Urabe 《Applied physics. B, Lasers and optics》1995,61(3):285-289
Be+ ions trapped in a Penning trap are laser-cooled to about 10 mK. The excitation spectra of ion clouds containing about 500 ions are obtained by scanning the frequency of the cooling laser and discontinuities in these spectra are observed because of phase transitions. When the cooled ions are heated electrically by applying an rf voltage, no phase transition occurs and the spectra become continuous. Two-dimensional measurement of the ion clouds is carried out and the abrupt change in the shape of the ion cloud due to the phase transition is observed. When many ions are trapped and cooled, the phase transition occurs partially and a transient state where two states are mixed can be observed. The static properties of the ions are also measured by using an additional probe laser and the results of experimental measurements are compared with theoretical predictions. 相似文献