全文获取类型
收费全文 | 1608篇 |
免费 | 65篇 |
国内免费 | 7篇 |
专业分类
化学 | 1331篇 |
晶体学 | 10篇 |
力学 | 14篇 |
数学 | 73篇 |
物理学 | 252篇 |
出版年
2023年 | 16篇 |
2022年 | 20篇 |
2021年 | 20篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 26篇 |
2017年 | 16篇 |
2016年 | 42篇 |
2015年 | 33篇 |
2014年 | 48篇 |
2013年 | 84篇 |
2012年 | 142篇 |
2011年 | 111篇 |
2010年 | 61篇 |
2009年 | 71篇 |
2008年 | 113篇 |
2007年 | 122篇 |
2006年 | 125篇 |
2005年 | 95篇 |
2004年 | 77篇 |
2003年 | 59篇 |
2002年 | 42篇 |
2001年 | 26篇 |
2000年 | 23篇 |
1999年 | 12篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 7篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1988年 | 12篇 |
1986年 | 7篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1971年 | 6篇 |
1969年 | 4篇 |
排序方式: 共有1680条查询结果,搜索用时 15 毫秒
101.
A systematic perturbation theory is developed for the ESR shift and is applied to the spin-1/2 Heisenberg antiferromagnetic chain with a general anisotropic exchange interaction. Using the Bethe ansatz technique, the resonance shift is obtained exactly for the whole range of temperature and magnetic field in the first order of the anisotropy. The obtained g shift strongly depends on magnetic fields at low temperature, showing a significant deviation from the previous classical result. 相似文献
102.
Norihiro?SadatoEmail author Hiroki?Yamada Tomohisa?Okada Masaki?Yoshida Takehiro?Hasegawa Ken-Ichi?Matsuki Yoshiharu?Yonekura Harumi?Itoh 《BMC neuroscience》2004,5(1):56
Background
Sign-language comprehension activates the auditory cortex in deaf subjects. It is not known whether this functional plasticity in the temporal cortex is age dependent. We conducted functional magnetic-resonance imaging in six deaf signers who lost their hearing before the age of 2 years, five deaf signers who were >5 years of age at the time of hearing loss and six signers with normal hearing. The task was sentence comprehension in Japanese sign language. 相似文献103.
104.
105.
Peter D. Mlynek Masaki Kawano Michael A. Kozee Lawrence F. Dahl 《Journal of Cluster Science》2001,12(1):313-338
Reactions of [Ni6(CO)12]2- (1) with CuBr2 have given rise in small yields (10%) to the first example of a close-packed copper-nickel carbonyl cluster; its formulation as [CuxNi35-x(CO)40]5- (with x=3 or 5) is based upon a low-temperature CCD X-ray crystallographic determination coupled with an elemental analysis and X-ray fluorescence measurements. This air-unstable black pentaanion (2) together with one co-crystallized bromide anion, six [NMe4]+ counterions, and one solvated acetone molecule comprise the crystallographic independent part in a monoclinic unit cell of P21/n symmetry (with Z=4). The geometrically unprecedented 35-atom hcp M(A)2M(B)3Ni30 polyhedron of pseudo-D3h symmetry consists of a central 15-atom equilateral 4M(B)3Ni12 triangle that is capped on both sides by two symmetry-related 10-atom equilateral 3M(A)Ni9 triangles. The 35-atom M(A)2M(B)3Ni30 core is encapsulated by 40 COs, whose connectivities, due to an extra CO ligand on one of the three triangular sides, reduce the pseudo D3h symmetry of the metal core to Cs. An elemental analysis via AA and X-ray fluorescence measurements resulted in Cu/Ni ratios of 3.2/31.8 and 3.7/31.3, respectively, that are consistent with the metal core being either Cu5Ni30 (i.e., M(A)=M(B)=Cu) or Cu3Ni32 (i.e., M(A)=Ni; M(B)=Cu). Several attempts to determine the actual stoichiometry of the metal core by use of electrospray FT/MS/ICR measurements were unsuccessful. The maximum metal-core diameter of 2 is ca. 0.41 nm parallel and 0.85 nm perpendicular to the principal 3-fold axis. 相似文献
106.
Georgia Benkart Seok-Jin Kang Masaki Kashiwara 《Journal of the American Mathematical Society》2000,13(2):295-331
A crystal base theory is introduced for the quantized enveloping algebra of the general linear Lie superalgebra , and an explicit realization of the crystal base is given in terms of semistandard tableaux. 相似文献
107.
Toshiki Yasokawa Ichirou Ishimaru Masahiro Kondo Shigeki Kuriyama Tsutomu Masaki Kaoru Takegawa Naotaka Tanaka 《Optical Review》2007,14(4):161-164
This paper describes a method for measuring the three-dimensional (3D) refractive-index distribution in a single cell. The
method can be used to observe the distribution of cell components without fluorescence staining. The two-dimensional optical
path length distributions from multiple directions are obtained by non-contact rotation of the cell. These optical path lengths
are converted into the line integrals of the refractive index, and the 3D refractive-index distribution is reconstructed by
means of computed tomography. The refractive-index distribution in a breast cancer cell can be measured using a phase-shifting
Mach—Zehnder interferometer in conjunction with proximal two-beam optical tweezers. 相似文献
108.
Takashi Kamimura Masaki Sato Takao Iwata 《Journal of magnetism and magnetic materials》1987,70(1-3):209-210
Transitions related to the spin-glass phase in Mn1−xTixSb
are revisited from the nonlinear ac susceptibility. Near the tricritical point (x≈0.8), the transition between ferromagnetic and reentrant spin-glass states is sharp. At x0.8, an anomally is found slightly above the temperature of usual spin-glass freezing. 相似文献
109.
110.