全文获取类型
收费全文 | 880篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
化学 | 696篇 |
晶体学 | 12篇 |
力学 | 19篇 |
数学 | 54篇 |
物理学 | 133篇 |
出版年
2023年 | 7篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 13篇 |
2019年 | 19篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 23篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 49篇 |
2012年 | 57篇 |
2011年 | 62篇 |
2010年 | 45篇 |
2009年 | 28篇 |
2008年 | 53篇 |
2007年 | 52篇 |
2006年 | 52篇 |
2005年 | 46篇 |
2004年 | 41篇 |
2003年 | 30篇 |
2002年 | 29篇 |
2001年 | 15篇 |
2000年 | 19篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 13篇 |
1991年 | 20篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1974年 | 6篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有914条查询结果,搜索用时 609 毫秒
101.
Yoshiyuki Kagei 《Journal of Differential Equations》2011,251(11):3248-3295
The initial boundary value problem for the compressible Navier-Stokes equation is considered in an infinite layer of Rn. It is proved that if n?3, then strong solutions to the compressible Navier-Stokes equation around parallel flows exist globally in time for sufficiently small initial perturbations, provided that the Reynolds and Mach numbers are sufficiently small. The proof is given by a variant of the Matsumura-Nishida energy method based on a decomposition of solutions associated with a spectral property of the linearized operator. 相似文献
102.
Hossain MZ Mukai K Yamashita Y Kawai H Yoshinobu J 《Chemical communications (Cambridge, England)》2011,47(37):10392-10394
The anisotropic correlation between buckled dimers on Si(100) was investigated by scanning tunneling microscopy. A bidentate ligand molecule was used to pin two neighboring dimers at 300 K. The chemically pinned dimer induces antiferromagnetic interaction along the dimer rows. Observed results agree well with Monte-Carlo simulations semi-quantitatively. 相似文献
103.
Dynamical features of hydrogen bonds in methanol–water mixtures have been analysed in terms of lifetime in the wide range of conditions, including supercritical states, using a molecular dynamics simulation with flexible potential models. Hydrogen bond characteristics in methanol–water mixtures were investigated by considering the combination of molecular species and donor–acceptor of hydrogen-bonded molecules. The hydrogen bond lifetimes mainly depend on temperature, and those in supercritical condition were about 1/10th of that at ambient condition. Focusing on the composition dependence of the hydrogen bond lifetime, the unique behaviour of that resulting from hydration structure was observed. Moreover, the molecular combination, which showed the largest hydrogen bond lifetime, was different for ambient and high temperature and high pressure conditions. The relationship between hydrogen bond lifetime and molar volume was also calculated to discuss the hydrogen bond lifetime in terms of the collision frequency of molecules and the intermolecular distance. 相似文献
104.
To develop a novel nucleoside analogue for the effective recognition of CG interruption in a homopurine-homopyrimidine tract of double-stranded DNA (dsDNA), we succeeded in the synthesis of a triplex-forming oligonucleotide (TFO) containing a novel 2′,4′-BNA (QB) bearing 1-isoquinolone as a nucleobase, and the triplex-forming ability and sequence-selectivity of the TFO (TFO-QB) were examined. On melting temperature (Tm) measurements, it was found that the TFO-QB formed a stable triplex DNA in a highly sequence-selective manner under near physiological conditions. 相似文献
105.
Yoshiyuki Ono 《Zeitschrift für Physik B Condensed Matter》1978,30(1):53-59
The effect of impurities on the static conductivity in the Fröhlich-Peierls phase is discussed by using the technique of the temperature Green function. The diagrams of the phonon drag type especially are shown to give the most important contribution to the static conductivity at low temperatures. The temperature dependence of this contribution is of the activation type with an activation energy equal to the pinning frequency of the phase mode of the charge density wave. The dependence of the preexponential factor on the impurity concentrations is also discussed.On leave of absence 相似文献
106.
Yoshiyuki Yamashita 《General Relativity and Gravitation》1984,16(2):99-110
A new method of calculation is given for arbitrary tensors in Riemann normal coordinates. Inventing a compact notation for an abstract form of tensors which is suitable to a noncommutative algebra system, we carry out the computer calculations to obtain coefficients of the Taylor expansion of tensors in Riemann normal coordinates. Explicit forms are given up to the tenth order for the metric tensor. 相似文献
107.
108.
Yoshiyuki Ono 《Physics letters. A》1977,60(3):257-259
Magnetothermal resistivity of an antiferromagnetic insulator is calculated by assuming that the thermal energy is carried mainly by phonons which are scattered by spin fluctuations. The spin system is treated by the Green function method. 相似文献
109.
110.
Seiji Yamaguchi Masao Mutoh Masaaki Shimakura Kunihiro Tsuzuki Yoshiyuki Kawase 《Journal of heterocyclic chemistry》1991,28(1):119-123
Some ω-(3-chromonyl)alkanoic acid derivatives, 1a and 2a , n = 4, 5; 3a, 4a and 5a , n = 2-6, were synthesized by cyclization of corresponding methyl ω-(2-hydroxybenzoyl)alkanoates 7b or ethyl ω-(2,4-dihydroxybenzoyl)alkanoates 8b with N,N-dimethylformamide-dimethyl acetal or acetic anhydride-DBU followed by hydrolysis. 相似文献