全文获取类型
收费全文 | 20596篇 |
免费 | 157篇 |
国内免费 | 89篇 |
专业分类
化学 | 10447篇 |
晶体学 | 419篇 |
力学 | 609篇 |
综合类 | 7篇 |
数学 | 1718篇 |
物理学 | 7642篇 |
出版年
2017年 | 159篇 |
2016年 | 247篇 |
2015年 | 171篇 |
2014年 | 268篇 |
2013年 | 848篇 |
2012年 | 579篇 |
2011年 | 642篇 |
2010年 | 472篇 |
2009年 | 478篇 |
2008年 | 633篇 |
2007年 | 679篇 |
2006年 | 641篇 |
2005年 | 590篇 |
2004年 | 509篇 |
2003年 | 473篇 |
2002年 | 467篇 |
2001年 | 691篇 |
2000年 | 512篇 |
1999年 | 430篇 |
1998年 | 350篇 |
1997年 | 332篇 |
1996年 | 303篇 |
1995年 | 381篇 |
1994年 | 349篇 |
1993年 | 320篇 |
1992年 | 347篇 |
1991年 | 389篇 |
1990年 | 362篇 |
1989年 | 364篇 |
1988年 | 335篇 |
1987年 | 334篇 |
1986年 | 328篇 |
1985年 | 407篇 |
1984年 | 424篇 |
1983年 | 318篇 |
1982年 | 327篇 |
1981年 | 350篇 |
1980年 | 324篇 |
1979年 | 336篇 |
1978年 | 335篇 |
1977年 | 314篇 |
1976年 | 332篇 |
1975年 | 290篇 |
1974年 | 283篇 |
1973年 | 299篇 |
1972年 | 182篇 |
1969年 | 159篇 |
1968年 | 189篇 |
1967年 | 334篇 |
1966年 | 284篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
71.
Kaon production is studied within the Giessen Boltzmann–Uehling–Uhlenbeck (GiBUU) model. Results are compared with experiment and with other models. The influence of the kaon potential on the kaon azimuthal distributions at SIS energies is considered. We also discuss the role of the many-body collisions at high-density phase of reaction. 相似文献
72.
We consider a multiperiod mean-variance model where the model parameters change according to a stochastic market. The mean
vector and covariance matrix of the random returns of risky assets all depend on the state of the market during any period
where the market process is assumed to follow a Markov chain. Dynamic programming is used to solve an auxiliary problem which,
in turn, gives the efficient frontier of the mean-variance formulation. An explicit expression is obtained for the efficient
frontier and an illustrative example is given to demonstrate the application of the procedure. 相似文献
73.
This paper provides exact and rigorous upper and lower bounds to the ground state energy of the Single Impurity Anderson Model in the limit of infiniteU. The upper bound approximates the ground state energy very well and the corresponding state may be used as a starting point for further investigations. The energy spectrum of the Single Impurity Anderson Model is calculated exactly for a special non-trivial model density of states describing the bare band electrons. All approaches introduced here are compared to this exact result and to other ground state energy calculations. 相似文献
74.
M. U. Belyi V. V. Grabovskii S. E. Zelenskii B. A. Okhrimenko 《Journal of Applied Spectroscopy》1991,54(2):137-141
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 2, pp. 229–233, February, 1991. 相似文献
75.
R. Resel M. Oehzelt O. Lengyel T.U. Schülli G. Hlawacek C. Teichert G. Koller 《Surface science》2006,600(19):4645-4649
A para-sexiphenyl monolayer of near up-right standing molecules (nominal thickness of 30 Å) is investigated in-situ by X-ray diffraction using synchrotron radiation and ex-situ by atomic force microscopy. A terrace like morphology is observed, the step height between the terraces is approximately one molecular length. The monolayer terraces, larger than 20 μm in size, are extended along the [0 0 1] direction of the TiO2(1 1 0) substrate i.e. along the Ti-O rows of the reconstructed substrate surface. The structure of the monolayer and its epitaxial relationship to the substrate is determined by grazing incidence X-ray diffraction. Extremely sharp diffraction peaks reveal high crystalline order within the monolayer, which was found to have the bulk structure of sexiphenyl. The monolayer terraces are epitaxially oriented with the (0 0 1) plane parallel to the substrate surface (out-of-plane order). Four epitaxial relationships are observed. This in-plane alignment is determined by the arrangement of the terminal phenyl rings of the sexiphenyl molecules parallel to the oxygen rows of the substrate. 相似文献
76.
S. Park T. U. Kampen T. Kachel P. Bressler W. Braun D. R. T. Zahn 《Applied Surface Science》2002,190(1-4):376-381
The interaction of Ag and In with a thin film of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) was studied by near-edge X-ray absorption fine structure (NEXAFS). Upon Ag deposition on a PTCDA film of 20 nm thickness the relative intensities and lineshapes, as well as the angular dependence of the spectra remains unchanged, illustrating the formation of a chemically unreactive Ag/PTCDA interface. On the other hand, the adsorption of 0.3 nm In strongly decreases the intensity of the π* resonances in C and O K-edge NEXAFS spectra. This is attributed to a strong charge transfer between In and PTCDA, leading to a redistribution of the charge in the molecule. However, the absence of a strong shift or new features and negligible dependence of peak intensities corresponding to π* resonances on the In thickness indicate that the interaction between In and PTCDA is not accompanied by a covalent bond formation. 相似文献
77.
78.
S. D. Borkute U. H. Nagvekar S. A. Balakrishnan R. S. Mani 《Journal of Radioanalytical and Nuclear Chemistry》1987,119(4):297-302
A novel method to eliminate T3 from gross sera/plasma based on prior treatment with 8-anilino-1-naphthalene sulphonic acid has been standardized. This method is rapid with a minimum loss of protein and uses only small quantities of charcoal. The treated sera have been tested for acceptance in the RIA system for routine assays. 相似文献
79.
80.