全文获取类型
收费全文 | 1521篇 |
免费 | 51篇 |
国内免费 | 16篇 |
专业分类
化学 | 1072篇 |
晶体学 | 11篇 |
力学 | 53篇 |
综合类 | 3篇 |
数学 | 107篇 |
物理学 | 342篇 |
出版年
2024年 | 11篇 |
2023年 | 14篇 |
2022年 | 64篇 |
2021年 | 68篇 |
2020年 | 42篇 |
2019年 | 49篇 |
2018年 | 41篇 |
2017年 | 30篇 |
2016年 | 71篇 |
2015年 | 52篇 |
2014年 | 60篇 |
2013年 | 127篇 |
2012年 | 109篇 |
2011年 | 121篇 |
2010年 | 60篇 |
2009年 | 65篇 |
2008年 | 63篇 |
2007年 | 53篇 |
2006年 | 61篇 |
2005年 | 51篇 |
2004年 | 44篇 |
2003年 | 39篇 |
2002年 | 32篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 13篇 |
1998年 | 10篇 |
1997年 | 11篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 9篇 |
1993年 | 12篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 14篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1962年 | 3篇 |
排序方式: 共有1588条查询结果,搜索用时 0 毫秒
111.
Part of this work was done while the second author was visiting the University of Georgia, Athens/Georgia, USA. 相似文献
112.
113.
(+)-Bis(methyl-1-naphthylphenylsilyl)mercury has been prepared, though probably in an optically impure state. Racemization without decomposition takes place at about 150°, and stereospecific cleavages of the Si—Hg bonds are possible. 相似文献
114.
Talat S. Rahman D.L. Mills J.E. Black 《Journal of Electron Spectroscopy and Related Phenomena》1983,29(1):199-212
Electron energy loss spectroscopy has proved a powerful probe of vibrational modes of a wide variety of adsorbed species. Here the primary focus has been on modes with frequency well above the maximum phonon frequency of the substrate. Examples are internal vibration modes of adsorbed molecules, possibly shifted significantly in frequency from their gas phase analogues, and high frequency vibrations of an adsorbed molecule or atom against the substrate. Recent experiments explore features in the energy loss spectrum with frequency below the maximum phonon frequency of the substrate, for ordered overlayers of atoms adsorbed on low index metal surfaces. We shall summarize our theoretical studies of such spectra for several adsorbate/substrate combinations, with emphasis oh the physical origin of the features which appear in the calculations. We obtain a good account of the existing data, within the framework of a rather simple lattice dynamical model, and the calculations show that the features which appear are quite sensitive to the symmetry of the adsorption sits, and other details of the surface geometry. We shall illustrate this with several specific examples. 相似文献
115.
Matiur Rahman 《Applied Mathematical Modelling》1981,5(2):109-121
The numerical development of resonance of a harbour of arbitrary shape and depth is studied. The harbour is subdivided into subregions according to the variations of bottom topography such that each subregion is of uniform depth. The Helmholtz wave equation is formulated in each subregion as an integral equation of the Green's theorem. The solution to the entire harbour basin is obtained by a matching procedure at the subregion boundaries. Here, we consider a harbour with basins of constant depths connected in series successively to accommodate a more complicated harbour geometry. An application of this study is made to Kincardine harbour with five basins connected in series successively. 相似文献
116.
Rahman M Younis 《Journal of Functional Analysis》1980,39(1):16-22
An interpolation result related to the Hardy space H∞(m) associated with a logmodular algebra A is presented, where m is the representing measure for some γ?M (A). The above result is used to answer a question rasied in [6]. 相似文献
117.
The theory of double resonance through the continuum is considered in view of incorporating statistical effects. After resolving the relevant Schrödi 相似文献
118.
119.
In this paper we study the local behaviour of a trigonometric polynomial around any of its zeros in terms of its estimated values at an adequate number of freely chosen points in . The freedom in the choice of sample points makes our results particularly convenient for numerical calculations. Analogous results for polynomials of the form are also proved.
120.
H.?AhmadEmail author M.?A.?J.?Miah M.?S.?Pervin M.?M.?Rahman 《Colloid and polymer science》2003,281(9):897-901
Modification of surface properties of polymer particles suitable for biomedical application has been done by incorporating acrylic acid (AA) as a hydrophilic component. First, submicron-sized poly(methyl methacrylate) seed particles were prepared by soap-free emulsion polymerization. Then, seeded emulsion copolymerizations were carried out with varying proportions of AA and methyl methacrylate (MMA). MMA was used as a comonomer to prevent the dissolution of AA from the polymer particles. The adsorption behaviors of different biomolecules indicate that the surface of the composite polymer particles is sufficiently hydrophilic, particularly at higher AA content. Specific activities of adsorbed trypsin on the composite polymer particles were also comparatively high compared to free trypsin, which suggests that the adsorbed trypsin undergoes only slight conformational change owing to the interaction with the surface of particles. 相似文献