全文获取类型
收费全文 | 6542篇 |
免费 | 713篇 |
国内免费 | 771篇 |
专业分类
化学 | 1957篇 |
晶体学 | 33篇 |
力学 | 572篇 |
综合类 | 169篇 |
数学 | 4123篇 |
物理学 | 1172篇 |
出版年
2024年 | 9篇 |
2023年 | 57篇 |
2022年 | 103篇 |
2021年 | 181篇 |
2020年 | 182篇 |
2019年 | 219篇 |
2018年 | 203篇 |
2017年 | 237篇 |
2016年 | 274篇 |
2015年 | 203篇 |
2014年 | 329篇 |
2013年 | 521篇 |
2012年 | 297篇 |
2011年 | 400篇 |
2010年 | 317篇 |
2009年 | 428篇 |
2008年 | 468篇 |
2007年 | 421篇 |
2006年 | 413篇 |
2005年 | 304篇 |
2004年 | 292篇 |
2003年 | 309篇 |
2002年 | 296篇 |
2001年 | 194篇 |
2000年 | 234篇 |
1999年 | 175篇 |
1998年 | 137篇 |
1997年 | 160篇 |
1996年 | 121篇 |
1995年 | 87篇 |
1994年 | 69篇 |
1993年 | 57篇 |
1992年 | 48篇 |
1991年 | 48篇 |
1990年 | 28篇 |
1989年 | 19篇 |
1988年 | 36篇 |
1987年 | 21篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1984年 | 23篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1936年 | 3篇 |
排序方式: 共有8026条查询结果,搜索用时 15 毫秒
41.
42.
In this paper, we exhibit a unified treatment of the mixed initial boundary value problem for second order (in time) parabolic linear differential equations in Banach spaces, whose boundary conditions are of a dynamical nature. Results regarding existence, uniqueness, continuous dependence (on initial data) and regularity of classical and strict solutions are established. Moreover, several examples are given as samples for possible applications.
43.
44.
Decentralized iterative learning control for a class of large scale interconnected dynamical systems
Hansheng Wu 《Journal of Mathematical Analysis and Applications》2007,327(1):233-245
The problem of decentralized iterative learning control for a class of large scale interconnected dynamical systems is considered. In this paper, it is assumed that the considered large scale dynamical systems are linear time-varying, and the interconnections between each subsystem are unknown. For such a class of uncertain large scale interconnected dynamical systems, a method is presented whereby a class of decentralized local iterative learning control schemes is constructed. It is also shown that under some given conditions, the constructed decentralized local iterative learning controllers can guarantee the asymptotic convergence of the local output error between the given desired local output and the actual local output of each subsystem through the iterative learning process. Finally, as a numerical example, the system coupled by two inverted pendulums is given to illustrate the application of the proposed decentralized iterative learning control schemes. 相似文献
45.
In this paper, the authors study the inclusion relations between Dirichlet type spaces DT and α-Bloch spacesβα by means of higher radial derivative. The strictness and the best possibility of the inclusion relations are shown with constructive methods.Furthermore, they sharpen one of the results when T = n, which proves that a conjecture in [7] is true. 相似文献
46.
本文得到Ω满足Dini型条件时,Marcinkiewicz积分交换子μΩ,b(f)的端点估计:|{x∈R~n:μΩ,b(f)(x)>λ}|≤c‖b‖BMO∫_(R~n)(|f(x)|)/λ(1+log+(|f(x)|)/λ)dx. 相似文献
47.
几何凸函数与琴生型不等式 总被引:20,自引:3,他引:17
吴善和 《数学的实践与认识》2004,34(2):155-163
给出几何凸函数的定义以及判定几何凸函数的方法 ,建立关于几何凸函数的琴生型不等式 ,最后给出它的应用 ,包括改进一些已知不等式和建立一些新不等式 . 相似文献
48.
We show that in each dimension n = 4k, k≥ 2, there exist infinite sequences of closed simply connected Riemannian n-manifolds with nonnegative sectional curvature and mutually distinct oriented cobordism type.
W. Tuschmann’s research was supported in part by a DFG Heisenberg Fellowship. 相似文献
49.
A PICARD TYPE THEOREM AND BLOCH LAW 总被引:9,自引:0,他引:9
Ye Yasheng 《数学年刊B辑(英文版)》1994,15(1):75-80
A PICARD TYPE THEOREM AND BLOCH LAW ¥YEYASHENGAbstract:Apicardtypetheoremisproved,andacounterexampleisgiventoshowthattheBolch... 相似文献
50.
S K Deshpande S M Chaudhari Ashok Pimpale A S Nigavekar S B Ogale V G Bhide 《Pramana》1991,37(4):373-385
An automated linear laboratory EXAFS spectrometer of the Johansson type has been indigenously developed. Only two translational
motions are required to achieve the necessary Rowland circle configuration for the (fixed) X-ray source, the dispersing and
focusing bent crystal and the receiving slit. With the available crystals the spectral region from 5 to 25 keV can be scanned.
The linear motions of the crystal and receiving slit including the detector assembly are achieved by employing software-controlled
DC motors and utilizing optical encoders for position sensing. The appropriate rotation of the crystal is achieved by the
geometry of the instrument. There is a facility to place the sample alternately in the path of the X-ray beam and out of the
path to record both the incident X-ray intensityI
0 and the transmitted intensityI employing the scintillation detector. An arrangement with a two-window proportional detector before the sample to measureI
0 and the scintillation detector to recordI is also developed; in this case it is not necessary to oscillate the sample. Fast electronic circuits are employed to minimize
counting errors. The instrument is user-friendly and it is operated through a menu-driven IBM compatible PC. EXAFS spectra
of high resolution have been recorded using the spectrometer and employing the Si(111) reflecting planes; the X-ray source
being a Rigaku 12 kW rotating anode with Cu target. We describe the spectrometer and discuss its performance with a few representative
spectra. 相似文献