全文获取类型
收费全文 | 505篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
化学 | 275篇 |
晶体学 | 9篇 |
力学 | 7篇 |
数学 | 96篇 |
物理学 | 126篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2016年 | 4篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 13篇 |
2011年 | 32篇 |
2010年 | 27篇 |
2009年 | 10篇 |
2008年 | 24篇 |
2007年 | 20篇 |
2006年 | 26篇 |
2005年 | 17篇 |
2004年 | 21篇 |
2003年 | 15篇 |
2002年 | 19篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 23篇 |
1998年 | 14篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 14篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 8篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1962年 | 3篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1955年 | 2篇 |
排序方式: 共有513条查询结果,搜索用时 15 毫秒
1.
2.
IR and Raman spectra of (NH4)3ZnCl5 have been recorded. The observed spectra have been analysed on the basis of the vibrations of ZnCl
4
2−
and NH
4
+
ions. The appearance of multiple Raman bands indicates the presence of two different types of ammonium ions. The effect of
anisotropic crystalline field over the ZnCl4 and NH4 tetrahedra is also discussed. The assignment of internal modes has been verified by the potential energy distribution calculations. 相似文献
3.
The main objects of study in this article are two classes of Rankin–Selberg L-functions, namely L(s,f×g) and L(s, sym2(g)× sym2(g)), where f,g are newforms, holomorphic or of Maass type, on the upper half plane, and sym2(g) denotes the symmetric square lift of g to GL(3). We prove that in general, i.e., when these L-functions are not divisible by L-functions of quadratic characters (such divisibility happening rarely), they do not admit any LandauSiegel zeros. Such zeros, which are real and close to s=1, are highly mysterious and are not expected to occur. There are corollaries of our result, one of them being a strong lower bound for special value at s=1, which is of interest both geometrically and analytically. One also gets this way a good bound onthe norm of sym2(g). 相似文献
4.
T. V. Ramakrishnan H. R. Krishnamurthy S. R. Hassan G. Venketeswara Pai 《Journal of Chemical Sciences》2003,115(5-6):767-774
Manganites of the LA1−x
Ca
x
MnO3 family show a variety of new and poorly understood electronic, magnetic and structural effects. Here we outline a new approach
recently proposed by us, where we argue that due to strong Jahn-Teller (JT) coupling with phonons the twofold degeneratee
g
states at the Mn sites dynamically reorganize themselves into localised, JT polaronsl with exponentially small inter-site hopping, and band-like, nonpolaronic statesb, leading to anew 2-band model for manganites which includes strong Coulomb and Hund’s couplings. We also discuss some results from a dynamical mean-field theory treatment
of the model which explains quantitatively a wide variety of experimental results, including insulator-metal transitions and
CMR, in terms of the influence of physical conditions on the relative energies and occupation of thel andb states. We argue that this microscopic coexistence of the two types of electronic states, and their relative occupation and
spatial correlation is the key to manganite physics.
Dedicated to Professor C N R Rao on his 70th birthday 相似文献
5.
6.
7.
8.
9.
10.
Carbonate radicals react with aliphatic amines by a dual mechanism, viz. (i) hydrogen abstraction and (ii) electron transfer. The former is more probable with primary amines. Tertiary amines react via electron transfer. Both mechanisms may operate in secondary amines. Cyclic tertiary amines react with different rates and their relative reactivities are explained on the basis of the concept of Hoffmann's ‘through bond’ interaction. 相似文献