全文获取类型
收费全文 | 545篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 340篇 |
晶体学 | 12篇 |
力学 | 8篇 |
数学 | 56篇 |
物理学 | 134篇 |
出版年
2018年 | 5篇 |
2016年 | 9篇 |
2014年 | 10篇 |
2013年 | 33篇 |
2012年 | 13篇 |
2011年 | 31篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 19篇 |
2007年 | 24篇 |
2006年 | 20篇 |
2005年 | 23篇 |
2004年 | 31篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 14篇 |
1996年 | 22篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1973年 | 5篇 |
1966年 | 2篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1960年 | 4篇 |
1956年 | 2篇 |
1948年 | 3篇 |
1942年 | 2篇 |
1935年 | 2篇 |
排序方式: 共有550条查询结果,搜索用时 15 毫秒
61.
62.
63.
Proceedings - Mathematical Sciences - The microwave spectrum of CD3NH2 has been studied in the region 24·9–38 KMc. The general experimental arrangements for observing the lines and... 相似文献
64.
The paramagnetic resonance absorption spectrum of the OD radical in the excited vibrational levels up to v = 5 of the ground , state has been observed at X-band frequencies. The theory of the Zeeman effect of a paramagnetic 2Π state of a light diatomic molecule has been applied to analyze the spectrum. The Λ-doubling frequencies, the molecular g factors, coefficients of the second order Zeeman effect, and the hyperfine interaction constants were determined for each of the vibrational levels. The experimental results agree reasonably well with the values calculated from (a) optical data and (b) ab initio data. The experimental determinations are still much better than theoretical calculations. 相似文献
65.
66.
Static dielectric constants and refractive indices of 2-butoxyethanol-n-hexane and-n-heptane mixtures were measured at 30 and 40°C and the various dielectric excess functionsviz. dielectric constants, molar polarizations, and orientation polarizations were evaluated. The excess dielectric constants and molar polarizations were found to be unsymmetrical and negative over the entire range of mole fraction. The trend in the variation of excess orientation polarization has shown three characteristic regions. The excess functions were smoothed through a variable degree polynomial. The results show the dominance of dipole-dipole interactions in the butoxyethanol deficient regions and weak specific interactions with unlike alkane molecules at higher butoxyethanol mole fractions. 相似文献
67.
Basaltic rocks contain magnetic grains oriented randomly in a nonmagnetic matrix. Experimental studies of low-field hysteresis of such rocks have shown partially and totally constricted hysteresis loops for some specimens. A possible origin of these constricted loops on the basis of interacting single domain behaviour is suggested. 相似文献
68.
69.
S.B.S. Sastry R.B. Tripathi C. Ramasastry 《Journal of Physics and Chemistry of Solids》1973,34(3):481-486
In the case of NaClO3 and KClO3 crystals, analysis of the long wavelength tail of their fundamental absorption revealed the active participation of the internal vibrations of the chlorate ion (Part I). In order to test the validity of the above interpretation the absorption spectra of two more halates with different anions namely sodium bromate and sodium iodate are analysed in a manner similar to that given in Part I. It is found that the principle internal vibrations of bromate and iodate ions are involved in the indirect transitions. The variation of indirect band gap with temperature is found to be ?2·5 × 10?4 eV/K and ?2·9 × 10?4 eV/K for sodium bromate and sodium iodate respectively. 相似文献
70.
Electron spin resonance studies have been carried out on Cu2+ ion doped in single crystals of cadmium maleate dihydrate at 303 and 77K. It has been found that Cu2+ enters this lattice interstitially. The spin Hamiltonian parameters have been evaluated and the ground state wave function
is found to be predominantly |X
2 −Y
2〉 with a slight admixture of |3Z
2 −r
2〉. 相似文献