全文获取类型
收费全文 | 12860篇 |
免费 | 302篇 |
国内免费 | 178篇 |
专业分类
化学 | 904篇 |
晶体学 | 88篇 |
力学 | 139篇 |
综合类 | 25篇 |
数学 | 10723篇 |
物理学 | 1461篇 |
出版年
2023年 | 24篇 |
2022年 | 57篇 |
2021年 | 90篇 |
2020年 | 60篇 |
2019年 | 290篇 |
2018年 | 314篇 |
2017年 | 195篇 |
2016年 | 115篇 |
2015年 | 138篇 |
2014年 | 325篇 |
2013年 | 621篇 |
2012年 | 459篇 |
2011年 | 720篇 |
2010年 | 572篇 |
2009年 | 839篇 |
2008年 | 913篇 |
2007年 | 947篇 |
2006年 | 799篇 |
2005年 | 606篇 |
2004年 | 475篇 |
2003年 | 339篇 |
2002年 | 341篇 |
2001年 | 311篇 |
2000年 | 314篇 |
1999年 | 346篇 |
1998年 | 281篇 |
1997年 | 243篇 |
1996年 | 298篇 |
1995年 | 281篇 |
1994年 | 289篇 |
1993年 | 202篇 |
1992年 | 180篇 |
1991年 | 126篇 |
1990年 | 120篇 |
1989年 | 135篇 |
1988年 | 88篇 |
1987年 | 94篇 |
1986年 | 74篇 |
1985年 | 103篇 |
1984年 | 90篇 |
1983年 | 54篇 |
1982年 | 83篇 |
1981年 | 69篇 |
1980年 | 77篇 |
1979年 | 43篇 |
1978年 | 56篇 |
1977年 | 48篇 |
1976年 | 43篇 |
1975年 | 14篇 |
1973年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
41.
Peter Clifford 《Annals of Combinatorics》2005,9(3):281-291
Motivated by recent results of Stanley, we generalize the rank of a partition λ to the rank of a shifted partition S(λ). We show that the number of bars required in a minimal bar tableau of S(λ) is max(o, e + (ℓ(λ) mod 2)), where o and e are the number of odd and even rows of λ. As a consequence we show that the irreducible projective characters of Sn vanish on certain conjugacy classes. Another corollary is a lower bound on the degree of the terms in the expansion of Schur’s
Qλ symmetric functions in terms of the power sum symmetric functions.
Received November 20, 2003 相似文献
42.
Extending to r > 1 a formula of the authors, we compute the expected reflection distance of a product of t random reflections in the complex reflection group G(r, 1, n). The result relies on an explicit decomposition of the reflection distance function into irreducible G(r, 1, n)-characters and on the eigenvalues of certain adjacency matrices.Received December 8, 2003 相似文献
43.
The First Intramolecular Charge Transfer Transition Based on 2-Ureido-4[1H]-pyrimidinone Binding Module 总被引:1,自引:0,他引:1
The first intramolecular charge transfer transition based on 2-ureido-4[1H]-pyrimidinone binding module was reported. 相似文献
44.
Walter Benz 《Monatshefte für Mathematik》2004,141(1):1-10
The lines of euclidean and hyperbolic geometries are characterized as metric lines in the sense of Blumenthal–Menger, and the lines of spherical and elliptic geometry as periodic ones. In euclidean geometries there do not exist periodic lines. 相似文献
45.
46.
Dorina Mitrea Marius Mitrea Jill Pipher 《Journal of Fourier Analysis and Applications》1997,3(2):131-192
We study boundary value problems for the time-harmonic form of the Maxwell equations, as well as for other related systems
of equations, on arbitrary Lipschitz domains in the three-dimensional Euclidean space. The main goal is to develop the corresponding
theory for Lp-integrable bounday data for optimal values of p's. We also discuss a number of relevant applications in electromagnetic scattering. 相似文献
47.
Guido Cortesani 《Annali dell'Universita di Ferrara》1997,43(1):27-49
Let Ω be an open and bounded subset ofR
n
with locally Lipschitz boundary. We prove that the functionsv∈SBV(Ω,R
m
) whose jump setS
vis essentially closed and polyhedral and which are of classW
k, ∞ (S
v,R
m) for every integerk are strongly dense inGSBV
p(Ω,R
m
), in the sense that every functionu inGSBV
p(Ω,R
m
) is approximated inL
p(Ω,R
m
) by a sequence of functions {v
k{j∈N with the described regularity such that the approximate gradients ∇v
jconverge inL
p(Ω,R
nm
) to the approximate gradient ∇u and the (n−1)-dimensional measure of the jump setsS
v
j converges to the (n−1)-dimensional measure ofS
u. The structure ofS
v can be further improved in casep≤2.
Sunto Sia Ω un aperto limitato diR n con frontiera localmente Lipschitziana. In questo lavoro si dimostra che le funzioniv∈SBV(Ω,R m ) con insieme di saltoS v essenzialmente chiuso e poliedrale che sono di classeW k, ∞ (S v,R m ) per ogni interok sono fortemente dense inGSBV p(Ω,R m ), nel senso che ogni funzioneu∈GSBV p(Ω,R m ) è approssimata inL p(Ω,R m ) da una successione di funzioni {v j}j∈N con la regolaritá descritta tali che i gradienti approssimati ∇v jconvergono inL p(Ω,R nm ) al gradiente approssimato ∇u e la misura (n−1)-dimensionale degli insiemi di saltoS v jconverge alla misura (n−1)-dimensionale diS u. La struttura diS vpuó essere migliorata nel caso in cuip≤2.相似文献
48.
Kevin Houston 《Inventiones Mathematicae》2002,147(3):471-485
The disentanglement of certain augmentations is shown to be the topological join of a disentanglement and a Milnor fibre.
The kth disentanglement of a finite map is defined and for corank 1 maps from ℂ
n
to ℂ
n
+1 it is shown that they are homotopically equivalent to a wedge of spheres. Applications to the Mond conjecture are given.
Oblatum 24-VII-2000 & 5-VII-2001?Published online: 12 October 2001 相似文献
49.
50.
A Pair of Dimeric Stilbene Epimers from Gnetum Montanum 总被引:1,自引:0,他引:1
GnetummontanumofgnetaceaisdistributedinsouthernChina.AsaChinesefOlkmedicine,itslianasareusedtotreatbronchitisandarthritis'.Previousinvestigationofthisspeciesledtotheisolationofsomealkaloidsanddibenzyletherde,i.ati.es2.lnourstudies,tenknowncomponentsincludingresveratrol,isohapontigenin,daucosterol,6-sitosterol,stearicacid,gnetifolinE,gnetol,isorhapontigenin-3-O-6-glucopyra(-)E-viniferinandgnetifolinCwereisolatedfromthesameresource.Atthesametime,apairoftraceepimerswereobtained.Thisisthefirste… 相似文献