全文获取类型
收费全文 | 5749篇 |
免费 | 504篇 |
国内免费 | 533篇 |
专业分类
化学 | 200篇 |
力学 | 88篇 |
综合类 | 54篇 |
数学 | 5177篇 |
物理学 | 1267篇 |
出版年
2024年 | 8篇 |
2023年 | 79篇 |
2022年 | 50篇 |
2021年 | 78篇 |
2020年 | 160篇 |
2019年 | 222篇 |
2018年 | 188篇 |
2017年 | 185篇 |
2016年 | 204篇 |
2015年 | 180篇 |
2014年 | 303篇 |
2013年 | 563篇 |
2012年 | 198篇 |
2011年 | 317篇 |
2010年 | 259篇 |
2009年 | 382篇 |
2008年 | 443篇 |
2007年 | 365篇 |
2006年 | 333篇 |
2005年 | 294篇 |
2004年 | 243篇 |
2003年 | 259篇 |
2002年 | 264篇 |
2001年 | 167篇 |
2000年 | 158篇 |
1999年 | 152篇 |
1998年 | 152篇 |
1997年 | 145篇 |
1996年 | 77篇 |
1995年 | 53篇 |
1994年 | 41篇 |
1993年 | 26篇 |
1992年 | 21篇 |
1991年 | 24篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 18篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 16篇 |
1979年 | 16篇 |
1978年 | 15篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1970年 | 2篇 |
排序方式: 共有6786条查询结果,搜索用时 0 毫秒
51.
Paul Caylor McKinney 《Journal of mathematical chemistry》2002,32(4):381-404
The solution of a generalized non-relativistic Schrödinger equation with radial potential energy V(r)=V
0(r/a
0)2–2 is presented. After reviewing the general properties of the radial ordinary differential equation, power series solutions are developed. The Green's function is constructed, its trace and the trace of its first iteration are calculated, and the ability of the traces to provide upper and lower bounds for the ground eigenvalue is examined. In addition, WKB-like solutions for the eigenvalues and eigenfunctions are derived. The approximation method yields valid eigenvalues for large quantum numbers (Rydberg states). 相似文献
52.
53.
Some Estimates for $θ$-Type Calderόn–Zygmund Operators and Linear Commutators on Certain Weighted Amalgam Spaces 下载免费PDF全文
In this paper, we first introduce some new kinds of weighted amalgam
spaces. Then we discuss the strong type and weak type estimates for a class of
Calderόn–Zygmund type operators $T_θ$ in these new weighted spaces. Furthermore,
the strong type estimate and endpoint estimate of linear commutators $[b, T_θ]$ formed
by $b$ and $T_θ$ are established. Also we study related problems about two-weight, weak
type inequalities for $T_θ$ and $[b, T_θ]$ in the weighted amalgam spaces and give some
results. 相似文献
54.
Jean Saint Raymond 《Rendiconti del Circolo Matematico di Palermo》1995,44(1):162-168
Let (T, ℐ, μ) be a σ-finite atomless measure space,p∈[1,∞),E a real Banach space andf a measurable function:E xT→ℝ. We denote byF the functionalF:
and byDom(F) its domain, it is the set {uεL
p(T,E):ū(t)=f(u),t)εL
1(T)}, and we prove that the sublevelsS(λ)={u:F(u)≤λ} are all connected in the subspaceDom(F) of the Banach spaceL
p(T, E). 相似文献
55.
Ronghui Ji 《K-Theory》1995,9(1):59-76
For certain classes of discrete groups we verify the idempotent conjectures for various group algebras by the method of cyclic cohomology. In particular, the Banach 1 (G) of a torsion free word hyperbolic groupG of Gromov contains no nontrivial idempotents. Moreover, the range of any tracial state onK
0(1(G)) is .Sponsored in part by a grant from the National Science Foundation. 相似文献
56.
给出 Banach空间列{Xi}i=1∞的 lp乘积B-凸的特征刻划, 证明B-凸空间上的每个黎斯算子可West分解,即分解成一个紧算子和一个拟幂 零算子的和. 相似文献
57.
Alain Joye 《Journal of statistical physics》1994,75(5-6):929-952
The spectrum of the Floquet operator associated with time-periodic perturbations of discrete Hamiltonians is considered. If the gap between successive eigenvalues
j
of the unperturbed Hamiltonian grows as
j
-
j-1
j
and the multiplicity of
j
grows asj
with >0 asj tends to infinity, then the corresponding Floquet operator possesses no absolutely continuous spectrum provided the perturbation is smooth enough. 相似文献
58.
We present an algorithm for numerically computing an absolutely continuous invariant measure associated with a piecewiseC
2 expanding mappingS: on a bounded region R
N. The method is based on the Galerkin projection principle for solving an operator equation in a Banach space. With the help of the modern notion of functions of bounded variation in multidimension, we prove the convergence of the algorithm. 相似文献
59.
Andrea Posilicano 《Potential Analysis》1996,5(3):241-271
We prove a convergence theorem for sequences of Diffusion Processes corresponding to Dirichlet Forms of the kind
.We obtain convergence in total variation norm of the corresponding probability measures on the path space C(+;d) under hypotheses which, for example, are satisfied in the case of H
loc
1
(
d
)-convergence of the 's, but we can allow more singular situations as regards the approximating sequences. We use then these results to give a criterion of convergence for generalized Schrödinger operators in which the potential function should not necessarily exists as a measurable function. We obtain convergence not only in strong resolvent sense, but we also obtain convergence in the uniform operator topology up to sets of arbitrarily small Lebesgue measure. Applications to the problem of the approximation of ordinary Schrödinger operators by generalized ones corresponding to zero-range interactions are given. 相似文献
60.
Michael Renardy 《Proceedings of the American Mathematical Society》1996,124(8):2451-2453
Let be the infinitesimal generator of a -semigroup of operators in a Hilbert space. We consider the class of operators , where is bounded. It is proved that the spectrum of determines the growth of the associated semigroup for ``most" operators (in the sense of Baire category).