全文获取类型
收费全文 | 3783篇 |
免费 | 201篇 |
国内免费 | 467篇 |
专业分类
化学 | 39篇 |
力学 | 45篇 |
综合类 | 49篇 |
数学 | 3850篇 |
物理学 | 468篇 |
出版年
2023年 | 51篇 |
2022年 | 22篇 |
2021年 | 45篇 |
2020年 | 78篇 |
2019年 | 102篇 |
2018年 | 102篇 |
2017年 | 95篇 |
2016年 | 110篇 |
2015年 | 89篇 |
2014年 | 180篇 |
2013年 | 337篇 |
2012年 | 110篇 |
2011年 | 202篇 |
2010年 | 152篇 |
2009年 | 265篇 |
2008年 | 317篇 |
2007年 | 261篇 |
2006年 | 234篇 |
2005年 | 228篇 |
2004年 | 176篇 |
2003年 | 197篇 |
2002年 | 173篇 |
2001年 | 119篇 |
2000年 | 108篇 |
1999年 | 122篇 |
1998年 | 113篇 |
1997年 | 121篇 |
1996年 | 62篇 |
1995年 | 43篇 |
1994年 | 29篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1973年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有4451条查询结果,搜索用时 31 毫秒
1.
2.
3.
宋显花 《数学的实践与认识》2021,(3):182-185
设B(X)是维数大于等于3的复Banach空间X上有界线性算子全体构成的代数.设A∈B(X),若Ax=x,则称x∈X是算子A的固定点.Fix(A)表示A的所有固定点的集合.本文刻画了B(X)上保持算子的Jordan积的固定点的满射. 相似文献
4.
Micha Rzeczkowski 《Mathematische Nachrichten》2021,294(1):118-131
In the paper we prove that the Nevanlinna counting function and the Carleson function of analytic self‐maps of finitely connected domains with smooth boundary are equivalent. Using this result we obtain the characterization of compact composition operators on Hardy–Orlicz spaces. 相似文献
5.
6.
The quantum effect plays an important role in quantum thermodynamics, and recently the application of an indefinite causal order to quantum thermodynamics has attracted much attention. Based on two trapped ions, we propose a scheme to add an indefinite causal order to the isochoric cooling stroke of an Otto engine through reservoir engineering. Then, we observe that the quasi-static efficiency of this heat engine is far beyond the efficiency of a normal Otto heat engine and may reach one. When the power is its maximum, the efficiency is also much higher than that of a normal Otto heat engine. This enhancement may originate from the non-equilibrium of the reservoir and the measurement on the control qubit. 相似文献
7.
《Journal of Pure and Applied Algebra》2022,226(8):107032
An iterative formula for the Green polynomial is given using the vertex operator realization of the Hall-Littlewood function. Based on this, (1) a general combinatorial formula of the Green polynomial is given; (2) several compact formulas are given for Green's polynomials associated with upper partitions of length ≤3 and the diagonal lengths ≤3; (3) a Murnaghan-Nakayama type formula for the Green polynomial is obtained; and (4) an iterative formula is derived for the bitrace of the finite general linear group G and the Iwahori-Hecke algebra of type A on the permutation module of G by its Borel subgroup. 相似文献
8.
二次量子化是研究生和高年级本科生量子力学课程中的重要内容.如何从一次量子化中的多粒子哈密顿量及波函数出发,自然地导出二次量子化中由产生和湮没算符表示的单体和两体算符,是一个既关键且又使初学者较难理解的步骤.以全同费米子系统为例,本文给出该步骤的一种自然且具有启发性的推导方法.该方法仅依赖于:多粒子波函数的对称性假设,Fock空间中“真空填充”的概念,以及全反对称多粒子波函数与Fock态的等价性. 相似文献
9.
Diego Maldonado 《Journal of Differential Equations》2018,264(2):624-678
We prove a Harnack inequality for nonnegative strong solutions to degenerate and singular elliptic PDEs modeled after certain convex functions and in the presence of unbounded drifts. Our main theorem extends the Harnack inequality for the linearized Monge–Ampère equation due to Caffarelli and Gutiérrez and it is related, although under different hypotheses, to a recent work by N.Q. Le.Since our results are shown to apply to the convex functions with and their tensor sums, the degenerate elliptic operators that we can consider include subelliptic Grushin and Grushin-like operators as well as a recent example by A. Montanari of a nondivergence-form subelliptic operator arising from the geometric theory of several complex variables. In the light of these applications, it follows that the Monge–Ampère quasi-metric structure can be regarded as an alternative to the usual Carnot–Carathéodory metric in the study of certain subelliptic PDEs. 相似文献
10.
Boris Baeumer Mihály Kovács Harish Sankaranarayanan 《Journal of Differential Equations》2018,264(2):1377-1410
We identify the stochastic processes associated with one-sided fractional partial differential equations on a bounded domain with various boundary conditions. This is essential for modelling using spatial fractional derivatives. We show well-posedness of the associated Cauchy problems in and . In order to do so we develop a new method of embedding finite state Markov processes into Feller processes on bounded domains and then show convergence of the respective Feller processes. This also gives a numerical approximation of the solution. The proof of well-posedness closes a gap in many numerical algorithm articles approximating solutions to fractional differential equations that use the Lax–Richtmyer Equivalence Theorem to prove convergence without checking well-posedness. 相似文献