全文获取类型
收费全文 | 13122篇 |
免费 | 1466篇 |
国内免费 | 1688篇 |
专业分类
化学 | 1053篇 |
晶体学 | 52篇 |
力学 | 891篇 |
综合类 | 333篇 |
数学 | 10328篇 |
物理学 | 3619篇 |
出版年
2024年 | 30篇 |
2023年 | 158篇 |
2022年 | 185篇 |
2021年 | 223篇 |
2020年 | 280篇 |
2019年 | 318篇 |
2018年 | 316篇 |
2017年 | 362篇 |
2016年 | 401篇 |
2015年 | 315篇 |
2014年 | 606篇 |
2013年 | 852篇 |
2012年 | 564篇 |
2011年 | 781篇 |
2010年 | 700篇 |
2009年 | 901篇 |
2008年 | 1022篇 |
2007年 | 1034篇 |
2006年 | 846篇 |
2005年 | 819篇 |
2004年 | 632篇 |
2003年 | 738篇 |
2002年 | 605篇 |
2001年 | 484篇 |
2000年 | 559篇 |
1999年 | 471篇 |
1998年 | 439篇 |
1997年 | 377篇 |
1996年 | 271篇 |
1995年 | 159篇 |
1994年 | 152篇 |
1993年 | 105篇 |
1992年 | 75篇 |
1991年 | 65篇 |
1990年 | 51篇 |
1989年 | 39篇 |
1988年 | 40篇 |
1987年 | 26篇 |
1986年 | 21篇 |
1985年 | 43篇 |
1984年 | 41篇 |
1983年 | 15篇 |
1982年 | 32篇 |
1981年 | 15篇 |
1980年 | 20篇 |
1979年 | 20篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1936年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
THE FIRST EXPERIMENT OF A THz GYROTRON WITH A PULSE MAGNET 总被引:1,自引:0,他引:1
T. Idehara H. Tsuchiya O. Watanabe La Agusu S. Mitsudo 《International Journal of Infrared and Millimeter Waves》2006,27(3):319-331
A THz gyrotron with a pulse magnet has been designed, constructed and operated in FIR FU. It is developed as one of high frequency
gyrotrons included in Gyrotron FU Series. The gyrotron has already achieved the first experimental result for high frequency
operations whose radiation frequency exceeds 1 THz. In this paper, the design detail and the operation test results for sub-terahertz
to terahertz range are described. The second harmonic operation is confirmed experimentally at the expected frequency of 1.005
THz due to TE6,11 cavity mode at the magnetic field intensity of 19.0 T. 相似文献
82.
Wei Gang SU Huai Jie ZHONG 《数学学报(英文版)》2006,22(2):515-522
This paper introduces the concept of the generalized Riesz operators and the concept of the generalized West decomposition of a general operator which generalizes the definition of the West decomposition of Riesz operators, and proves that the following three statements are equivalent on a general Banach space:
(a) Every generalized Riesz operator has the generalized West decomposition;
(b) Every operator makes strong Stampfli theorem true; Every operator has Apostol's compact correction. 相似文献
83.
Alexander Ya. Kruger 《Set-Valued Analysis》2006,14(2):187-206
The paper continues investigations of stationarity and regularity properties of collections of sets in normed spaces. It contains
a summary of different characterizations (both primal and dual) of regularity and a list of sufficient conditions for a collection
of sets to be regular. 相似文献
84.
HU Yun & SHEN Yuliang Department of Mathematics Suzhou University Suzhou China 《中国科学A辑(英文版)》2006,(7)
We will be mainly concerned with some important fiber spaces over Teichmuller spaces, including the Bers fiber space and Teichmuller curve, establishing an isomorphism theorem between "punctured" Teichmuller curves and determining the biholomorphic isomorphisms of these fiber spaces. 相似文献
85.
Howel Tong 《应用数学学报(英文版)》2002,18(2):177-184
Abstract I reflect upon the development of nonlinear time series analysis since 1990 by focusing on five majorareas of development. These areas include the interface between nonlinear time series analysis and chaos,thenonparametric/semiparametric approach,nonlinear state space modelling,financial time series and nonlinearmodelling of panels of time series. 相似文献
86.
一类多线性积分算子的端点有界性 总被引:3,自引:0,他引:3
本文对一类相关于非卷积型算子的多线性算子,证明了其在端点情形上的有界性,该算子包括Littlewood-Paley算子和Marcinkiewicz算子. 相似文献
87.
88.
Given a constant of motion for the one-dimensional harmonic oscillator with linear dissipation in the velocity, the problem to get the Hamiltonian for this system is pointed out, and the quantization up to second order in the perturbation approach is used to determine the modification on the eigenvalues when dissipation is taken into consideration. This quantization is realized using the constant of motion instead of the Hamiltonian.
PACS: 03.20.+i, 03.30.+p, 03.65.−w,03.65.Ca 相似文献
89.
We investigate function spaces of generalised smoothness of Besov and Triebel–Lizorkin type. Equivalent quasi-norms in terms
of maximal functions and local means are given. An atomic decomposition theorem for this type of spaces is proved.
Mathematics Subject Classification (2000) 46E35 相似文献
90.
Bin Han 《Advances in Computational Mathematics》2006,24(1-4):375-403
In this paper, we present a necessary and sufficient condition for the existence of solutions in a Sobolev space Wpk(ℝs) (1≤p≤∞) to a vector refinement equation with a general dilation matrix. The criterion is constructive and can be implemented.
Rate of convergence of vector cascade algorithms in a Sobolev space Wpk(ℝs) will be investigated. When the dilation matrix is isotropic, a characterization will be given for the Lp (1≤p≤∞) critical smoothness exponent of a refinable function vector without the assumption of stability on the refinable function
vector. As a consequence, we show that if a compactly supported function vector φ∈Lp(ℝs) (φ∈C(ℝs) when p=∞) satisfies a refinement equation with a finitely supported matrix mask, then all the components of φ must belong to a Lipschitz
space Lip(ν,Lp(ℝs)) for some ν>0. This paper generalizes the results in R.Q. Jia, K.S. Lau and D.X. Zhou (J. Fourier Anal. Appl. 7 (2001) 143–167)
in the univariate setting to the multivariate setting.
Dedicated to Professor Charles A. Micchelli on the occasion of his 60th birthday
Mathematics subject classifications (2000) 42C20, 41A25, 39B12.
Research was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC Canada) under Grant
G121210654. 相似文献