全文获取类型
收费全文 | 14602篇 |
免费 | 1937篇 |
国内免费 | 1622篇 |
专业分类
化学 | 8643篇 |
晶体学 | 338篇 |
力学 | 1249篇 |
综合类 | 139篇 |
数学 | 3164篇 |
物理学 | 4628篇 |
出版年
2024年 | 25篇 |
2023年 | 128篇 |
2022年 | 285篇 |
2021年 | 367篇 |
2020年 | 435篇 |
2019年 | 415篇 |
2018年 | 414篇 |
2017年 | 479篇 |
2016年 | 582篇 |
2015年 | 457篇 |
2014年 | 656篇 |
2013年 | 1369篇 |
2012年 | 745篇 |
2011年 | 774篇 |
2010年 | 611篇 |
2009年 | 807篇 |
2008年 | 903篇 |
2007年 | 933篇 |
2006年 | 889篇 |
2005年 | 786篇 |
2004年 | 753篇 |
2003年 | 662篇 |
2002年 | 672篇 |
2001年 | 547篇 |
2000年 | 548篇 |
1999年 | 451篇 |
1998年 | 374篇 |
1997年 | 343篇 |
1996年 | 294篇 |
1995年 | 283篇 |
1994年 | 248篇 |
1993年 | 217篇 |
1992年 | 176篇 |
1991年 | 88篇 |
1990年 | 73篇 |
1989年 | 50篇 |
1988年 | 62篇 |
1987年 | 43篇 |
1986年 | 34篇 |
1985年 | 35篇 |
1984年 | 32篇 |
1983年 | 19篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 13篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 3篇 |
1976年 | 12篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Lá szló L. Stachó Borut Zalar 《Proceedings of the American Mathematical Society》2004,132(10):3019-3025
We prove that every JB* triple with rank one bicircular projection is a direct sum of two ideals, one of which is isometrically isomorphic to a Hilbert space.
82.
83.
G. Lanyi 《Foundations of Physics》2003,33(3):511-528
In 1916, Einstein rederived the blackbody radiation law of Planck that originated the idea of quantized energy one hundred years ago. For this purpose, Einstein introduced the concept of transition probability, which had a profound influence on the development of quantum theory. In this article, we adopt Einstein's assumptions with two exceptions and seek the statistical condition for the thermal equilibrium of matter without referring to the inner details of either statistical thermodynamics or quantum theory. It is shown that the conditions of thermodynamic equilibrium of electromagnetic radiation and the energy balance of thermal radiation by the matter, between any of its two energy-states, not only result in Planck's radiation law and the Bohr frequency condition, but they remarkably yield the law of the statistical thermal equilibrium of matter: the Maxwell–Boltzmann distribution. Since the transition probabilities of the modern quantum theory of radiation coincide with their definition in Einstein's theory of blackbody radiation, the presented deduction of the Maxwell–Boltzmann distribution is equally valid within the bounds of modern quantum theory. Consequently, within the framework of the fundamental assumptions, the Maxwell–Boltzmann distribution of energy-states is not only a sufficient, but a necessary condition for thermal equilibrium between the matter and radiation. 相似文献
84.
代数$A$ 称为不可分解的,如果 $A$ 不能分解成理想的直和.文中将证明满足$C(L_{\bar{0}})=C(L)=\{0\}$的限制李超代数能够分解成不可分解限制理想的直和,这种分解在不计理想次序的前提下是唯一的.而且还证明了限制李超代数的一些结果. 相似文献
85.
S. Mentus Dijana Jelić Veselinka Grudić 《Journal of Thermal Analysis and Calorimetry》2007,90(2):393-397
Thermal decomposition of lanthanum nitrate to lanthanum oxide was carried out by both temperature programmed heating (TPH)
and citrate-gel combustion. The temperature programmed heating was carried out under flow of oxidizing (air), neutral (nitrogen)
and reducing (25 vol.% hydrogen+argone mixture) gases, and the processes were controlled by simultaneous thermogravimetry
and differential thermal analysis. It was shown that hydrogen atmosphere helps to reduce temperatures of all decomposition
steps. The results of TPH were utilized to check the nature of residues in the products of lanthanum nitrate-to-oxide conversion
performed via citrate-gel combustion technique. 相似文献
86.
Idealization of a decomposition theorem 总被引:1,自引:1,他引:0
In 1986, Tong [13] proved that a function f : (X,τ)→(Y,φ) is continuous if and only if it is α-continuous and A-continuous. We extend this decomposition of continuity in terms of ideals. First, we introduce the notions of regular-I-closed sets, A
I-sets and A
I -continuous functions in ideal topological spaces and investigate their properties. Then, we show that a function f : (X,τ,I)→(Y, φ) is continuous if and only if it is α-I-continuous and A
I-continuous.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
87.
C. Baumgarten B. Braun G. Court G. Ciullo P. Ferretti G. Graw W. Haeberli M. Henoch R. Hertenberger N. Koch H. Kolster P. Lenisa A. Nass S.P. Pod'yachev D. Reggiani K. Rith M.C. Simani E. Steffens J. Stewart T. Wise 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):37-49
The use of storage cells has become a standard technique for internal gas targets in conjunction with high energy storage
rings. In case of spin-polarized hydrogen and deuterium gas targets the interaction of the injected atoms with the walls of
the storage cell can lead to depolarization and recombination. Thus the number of wall collisions of the atoms in the target
gas is important for modeling the processes of spin relaxation and recombination. It is shown in this article that the diffusion
process of rarefied gases in long tubes or storage cells can be described with the help of the one-dimensional diffusion equation.
Mathematical methods are presented that allow one to calculate collision age distributions (CAD) and their moments analytically.
These methods provide a better understanding of the different aspects of diffusion than Monte Carlo calculations. Additionally
it is shown that measurements of the atomic density or polarization of a gas sample taken from the center of the tube allow
one to determine the possible range of the corresponding density weighted average values along the tube. The calculations
are applied to the storage cell geometry of the HERMES internal polarized hydrogen and deuterium gas target.
Received 9 July 2001 and Received in final form 18 September 2001 相似文献
88.
89.
90.
Eric Flauraud Frdric Nataf Isabelle Faille Roland Masson 《Comptes Rendus Mecanique》2003,331(12):849-855
We present in this paper a domain decomposition method to treat faults in geological basin modeling. The particularity of this model is that the faults whose widths are very small in comparison with the basin size, are not characterized as subdomains any more but as interfaces between sedimentary blocks. The originality of this work lies in the formulation of this new fault model and in the definition and the computation of the interface conditions between the subdomains. To cite this article: E. Flauraud et al., C. R. Mecanique 331 (2003). 相似文献