全文获取类型
收费全文 | 254606篇 |
免费 | 10506篇 |
国内免费 | 6187篇 |
专业分类
化学 | 138754篇 |
晶体学 | 3945篇 |
力学 | 12251篇 |
综合类 | 333篇 |
数学 | 28369篇 |
物理学 | 87647篇 |
出版年
2022年 | 3144篇 |
2021年 | 3628篇 |
2020年 | 4006篇 |
2019年 | 4080篇 |
2018年 | 4443篇 |
2017年 | 4291篇 |
2016年 | 6250篇 |
2015年 | 4786篇 |
2014年 | 6568篇 |
2013年 | 12847篇 |
2012年 | 11896篇 |
2011年 | 13424篇 |
2010年 | 9291篇 |
2009年 | 8959篇 |
2008年 | 11179篇 |
2007年 | 10961篇 |
2006年 | 10295篇 |
2005年 | 9111篇 |
2004年 | 8115篇 |
2003年 | 7001篇 |
2002年 | 6720篇 |
2001年 | 7365篇 |
2000年 | 5774篇 |
1999年 | 4812篇 |
1998年 | 3870篇 |
1997年 | 3836篇 |
1996年 | 3567篇 |
1995年 | 3329篇 |
1994年 | 3063篇 |
1993年 | 2852篇 |
1992年 | 3109篇 |
1991年 | 3049篇 |
1990年 | 2921篇 |
1989年 | 2629篇 |
1988年 | 2623篇 |
1987年 | 2606篇 |
1986年 | 2434篇 |
1985年 | 3093篇 |
1984年 | 3302篇 |
1983年 | 2721篇 |
1982年 | 2856篇 |
1981年 | 2809篇 |
1980年 | 2665篇 |
1979年 | 2745篇 |
1978年 | 2829篇 |
1977年 | 2836篇 |
1976年 | 2905篇 |
1975年 | 2689篇 |
1974年 | 2651篇 |
1973年 | 2791篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Varfolomeev S. D. Panin A. A. Semenova N. A. Ublinskiy M. V. Akhadov T. A. Bykov V. I. Tsybenova S. B. 《Russian Chemical Bulletin》2022,71(3):591-594
A kinetic study of the effect of thermoheliox (inhalation of a helium and oxygen mixture, 70 °C) on the functional hemodynamics of the human brain by functional magnetic resonance imaging was carried out. The dynamic responses of the BOLD signal were found to be biphasic. An empirical equation describing the first phase of the hemodynamic response to visual stimulus was proposed. It was shown that preliminary inhalation of thermoheliox stimulates the hemodynamic responses by slowing down the vasoconstriction.
相似文献12.
Theoretical and Mathematical Physics - Dynamic systems acting on the plane and possessing the Wada property have been observed. There exist only two topological types, symmetric and antisymmetric,... 相似文献
13.
Let p ∈ [1, ∞), q ∈ [1, ∞), α∈ R, and s be a non-negative integer. Inspired by the space JNp introduced by John and Nirenberg(1961) and the space B introduced by Bourgain et al.(2015), we introduce a special John-Nirenberg-Campanato space JNcon(p,q,s) over Rn or a given cube of R;with finite side length via congruent subcubes, which are of some amalgam features. The limit space of such spaces as p →∞ is just the Campanato space which coincides with the space BMO(the space of functions with bounded mean oscillations)when α = 0. Moreover, a vanishing subspace of this new space is introduced, and its equivalent characterization is established as well, which is a counterpart of the known characterization for the classical space VMO(the space of functions with vanishing mean oscillations) over Rn or a given cube of Rn with finite side length.Furthermore, some VMO-H1-BMO-type results for this new space are also obtained, which are based on the aforementioned vanishing subspaces and the Hardy-type space defined via congruent cubes in this article. The geometrical properties of both the Euclidean space via its dyadic system and congruent cubes play a key role in the proofs of all these results. 相似文献
14.
JETP Letters - The concept and design optimization of a polarization-independent dielectric metasurface for the spatial separation of scalar light beams with different values of the orbital angular... 相似文献
15.
Technical Physics - Taking damping into account in the problems of structural dynamics is an important and nontrivial problem. Its complexity is primarily determined by the required specification... 相似文献
16.
Physics of Atomic Nuclei - In this paper, the analysis of the relation between the multiplication factor of neutrons of the multiplying system measured in critical experiments and the system... 相似文献
17.
Siberian Mathematical Journal - Suppose that $ n $ is an integer, $ n\geq 3 $ . We prove that a periodic group saturated with a set of the finite simple groups $ O_{2n+1}(q) $ , where $ q $ is... 相似文献
18.
M. Amar D. Andreucci R. Gianni C. Timofte 《Journal of Mathematical Analysis and Applications》2021,493(2):124533
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation. 相似文献
19.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
20.
Kopytov G. F. Malyshko V. V. Goryachko A. I. Sharafan M. V. Churkina A. V. Moiseev A. V. Shashkov D. I. Lyasota O. M. 《Russian Physics Journal》2021,64(2):255-260
Russian Physics Journal - The specific features of the sorption activity of silver nanoparticles (AgNPs) on biodegradable polymers of natural (collagen) and artificial (polyamide 6.6) origin have... 相似文献