全文获取类型
收费全文 | 2022篇 |
免费 | 55篇 |
国内免费 | 4篇 |
专业分类
化学 | 1458篇 |
晶体学 | 30篇 |
力学 | 47篇 |
数学 | 88篇 |
物理学 | 458篇 |
出版年
2022年 | 15篇 |
2021年 | 17篇 |
2020年 | 31篇 |
2019年 | 29篇 |
2018年 | 14篇 |
2017年 | 17篇 |
2016年 | 31篇 |
2015年 | 30篇 |
2014年 | 29篇 |
2013年 | 84篇 |
2012年 | 92篇 |
2011年 | 99篇 |
2010年 | 56篇 |
2009年 | 49篇 |
2008年 | 98篇 |
2007年 | 103篇 |
2006年 | 108篇 |
2005年 | 93篇 |
2004年 | 98篇 |
2003年 | 78篇 |
2002年 | 68篇 |
2001年 | 54篇 |
2000年 | 45篇 |
1999年 | 32篇 |
1998年 | 24篇 |
1997年 | 28篇 |
1996年 | 34篇 |
1995年 | 30篇 |
1994年 | 30篇 |
1993年 | 28篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 30篇 |
1984年 | 39篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 32篇 |
1979年 | 22篇 |
1978年 | 23篇 |
1977年 | 16篇 |
1976年 | 30篇 |
1975年 | 25篇 |
1974年 | 30篇 |
1973年 | 27篇 |
排序方式: 共有2081条查询结果,搜索用时 15 毫秒
1.
Optical Review - This paper demonstrates a method to estimate the depth of a fluorescence object in turbid media using dual-wavelength excited photodynamic diagnosis, to aid in the invasion depth... 相似文献
2.
Hirokazu Nishimura 《International Journal of Theoretical Physics》1995,34(2):211-228
The notion of a manual, introduced and investigated in detail by Foulis, Randall, and their followers, has turned out to be further reaching than its originators had envisaged. Its omnipresence is comparable with the notion of a sheaf, whose significance is well recognized by every pure and applied mathematician. The principal concern of this paper is to give an appropriate vehicle, as general as possible, by which the theory of manuals can be developed. The vehicle is called an orthogonal category, which is akin to the notion of a category with coproducts. Orthogonal categories provide also a new perspective on the notion of a sheaf over a complete Boolean algebra, deepening our comprehension of Boolean mathematics and paving the way to quantum mathematics. 相似文献
3.
Shuichi Ishida Keiki Takeda Atsushi Okamoto Ichiro Shibasaki 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):255
Magnetoresistance (MR) effects have been investigated in perpendicular and parallel magnetic fields at 300, 80 K and liquid He temperatures for undoped InSb thin films 0.1–2.3 μm thick grown on GaAs(1 0 0) substrates by MBE. At high temperatures, the intrinsic carriers show the parabolic negative MR observable only in magnetic fields parallel to the film. The skipping-orbit effect due to surface boundary scattering in the classical orbits in the plane vertical to the film has been argued to be responsible for the negative MR. At low temperatures (T=80 K), the transport is dominated by the two-dimensional (2D) electrons in the accumulation layers at the InSb/GaAs(1 0 0) hetero interface; MR is positive and shows a logarithmic increase with anisotropy between parallel and perpendicular field orientation, arising from the 2D weak anti-localization (WAL) that reflects the interplay between the spin-Zeeman effect and strong spin–orbit interaction caused by the asymmetric potential at the interface (Rashba term). The zero-field spin splitting energy of Δ013 meV, the electron effective mass of m*0.10m0 seven times of the band edge mass in bulk InSb and the effective g-factor of |g*|15 in the accumulation layer have been inferred from fits of MR for the 0.1 μm thick film to the 2D WL theory. 相似文献
4.
In this paper, we study Schrödinger type operator on a Riemannian manifold. Under some assumptions on a potential function, we characterize the domain of the square root of the Schrödinger type operator on L p space. In the proof, the defective intertwining properties and the Littlewood-Paley inequalities play important roles. 相似文献
5.
6.
S. Homma-Takeda Y. Nishimura Y. Watanabe H. Imaseki M. Yukawa 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(3):521-525
Stage-specific and age-dependent profiles of zinc, copper, manganese, and selenium in testis were examined in Wistar rats
by both inductively coupled argon plasma-mass spectrometry (ICP-MS) with a microdissection technique and in situ elemental
imaging of micro-PIXE analysis. The young adult animals (10 weeks old) contained higher levels of zinc and manganese in the
seminiferous tubules at stages VII-VIII than stages XI through VI and IX-X and the levels were higher than those of the immature
and old animals. Copper and selenium levels at stages VII-VIII of the young adult animals were also higher than those of the
immature and old animals. In stages VII and VIII, zinc was higher in the central area of the seminiferous epithelium, where
spermatozoa were localized, demonstrating a cell-specific property.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
8.
9.
Muonium in liquid SiCl has been observed for the first time at low temperature (−65°C) The observed polarization of muonium
is as much as 25% of the total spin polarization and shows a fast relaxation rate. 相似文献
10.