全文获取类型
收费全文 | 15381篇 |
免费 | 716篇 |
国内免费 | 145篇 |
专业分类
化学 | 10050篇 |
晶体学 | 50篇 |
力学 | 323篇 |
综合类 | 1篇 |
数学 | 2926篇 |
物理学 | 2892篇 |
出版年
2023年 | 141篇 |
2022年 | 290篇 |
2021年 | 348篇 |
2020年 | 419篇 |
2019年 | 495篇 |
2018年 | 379篇 |
2017年 | 291篇 |
2016年 | 597篇 |
2015年 | 564篇 |
2014年 | 548篇 |
2013年 | 913篇 |
2012年 | 1078篇 |
2011年 | 1276篇 |
2010年 | 677篇 |
2009年 | 562篇 |
2008年 | 908篇 |
2007年 | 830篇 |
2006年 | 838篇 |
2005年 | 773篇 |
2004年 | 605篇 |
2003年 | 470篇 |
2002年 | 436篇 |
2001年 | 239篇 |
2000年 | 170篇 |
1999年 | 181篇 |
1998年 | 155篇 |
1997年 | 164篇 |
1996年 | 167篇 |
1995年 | 144篇 |
1994年 | 113篇 |
1993年 | 101篇 |
1992年 | 85篇 |
1991年 | 76篇 |
1990年 | 64篇 |
1989年 | 40篇 |
1988年 | 44篇 |
1987年 | 47篇 |
1986年 | 44篇 |
1985年 | 69篇 |
1984年 | 57篇 |
1983年 | 34篇 |
1982年 | 58篇 |
1981年 | 49篇 |
1980年 | 44篇 |
1979年 | 40篇 |
1978年 | 44篇 |
1977年 | 41篇 |
1976年 | 47篇 |
1974年 | 34篇 |
1973年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.
We consider systems of GI/M/1 type with bulk arrivals, bulk service and exponential server vacations. The generating functions of the steady-state probabilities
of the embedded Markov chain are found in terms of Riemann boundary value problems, a necessary and sufficient condition of
ergodicity is proved. Explicit formulas are obtained for the case where the generating function of the arrival group size
is rational. Resonance between the vacation rate and the system is studied. Complete formulas are given for the cases of single
and geometric arrivals.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
25.
The classical Yang–Baxter equation(CYBE) is an algebraic equation central in the theory of integrable systems. Its nondegenerate
solutions were classified by Belavin and Drinfeld. Quantization of CYBE led to the theory of quantum groups. A geometric interpretation
of CYBE was given by Drinfeld and gave rise to the theory of Poisson–Lie groups.
The classical dynamical Yang–Baxter equation (CDYBE) is an important differential equation analogous to CYBE and introduced
by Felder as the consistency condition for the differential Knizhnik–Zamolodchikov–Bernard equations for correlation functions
in conformal field theory on tori. Quantization of CDYBE allowed Felder to introduce an interesting elliptic analog of quantum
groups. It becomes clear that numerous important notions and results connected with CYBE have dynamical analogs.
In this paper we classify solutions to CDYBE and give geometric interpretation to CDYBE. The classification and interpretation
are remarkably analogous to the Belavin–Drinfeld picture.
Received: 24 March 1997 / Accepted: 20 June 1997 相似文献
26.
Alexander P. Schuster 《Proceedings of the American Mathematical Society》1997,125(6):1717-1725
Properties of the unions of sampling and interpolation sets for Bergman spaces are discussed in conjunction with the examples given by Seip (1993). Their relationship to the classical interpolation sequences is explored. In addition, the role played by canonical divisors in the study of these sets is examined and an example of a sampling set is constructed in the disk.
27.
Alexander Afriat 《Foundations of Physics Letters》1995,8(5):467-480
We consider the question of factorizability in tensor product spaces, and argue that the correlations associated with entangled states are even more problematic in the general case involving any tensor product of Hilbert spaces, than in the Einstein, Podolsky, and Rosen case with only two [1]. 相似文献
28.
29.
Alexander N Shivanyuk Dmitry M Rudkevich David N Reinhoudt 《Tetrahedron letters》1996,37(52):9341-9344
An assembly of cation receptor 1 and anion receptor 2 via the hydrogen bonding melamine-barbiturate structural motif complexes sodium thiocyanate, sodium iodide, and sodium azide in apolar solvents. 相似文献
30.
Dextran-modified iron oxide nanoparticles 总被引:1,自引:0,他引:1
Dextran-modified iron oxide nanoparticles were prepared by precipitation of Fe(Ⅱ) and Fe(Ⅲ) salts with ammonium hydroxide by two methods. Iron oxide was precipitated either in the presence of dextran solution, or the dextran solution was added after precipitation. In the second method, the iron oxide particle size and size distribution could be controlled depending on the concentration of dextran in the solution. The nanoparticles were characterized by size-exclusion chromatography, transmission electron microscopy and dynamic light scattering. Optimal conditions for preparation of stable iron oxide colloid particles were determined, The dextran/iron oxide ratio 0-0,16 used in precipitation of iron salts can be recommended for synthesis of nanoparticles suitable for biomedical applications, as the colloid does not contain excess dextran and does not coagulate. 相似文献