全文获取类型
收费全文 | 350篇 |
免费 | 10篇 |
国内免费 | 29篇 |
专业分类
化学 | 20篇 |
晶体学 | 2篇 |
力学 | 4篇 |
综合类 | 19篇 |
数学 | 287篇 |
物理学 | 57篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 23篇 |
2013年 | 29篇 |
2012年 | 9篇 |
2011年 | 21篇 |
2010年 | 20篇 |
2009年 | 14篇 |
2008年 | 34篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 13篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有389条查询结果,搜索用时 406 毫秒
61.
The mean transformations M(A,?B) are linear mappings and they are analogues of the matrix means of A,?B?≥?0. They are defined by operator monotone functions. In this article several properties are described and a part of them characterize the concept. 相似文献
62.
Let A
1,…,A
N
be complex self-adjoint matrices and let ρ be a density matrix. The Robertson uncertainty principle
gives a bound for the quantum generalized covariance in terms of the commutators [A
h
,A
j
]. The right side matrix is antisymmetric and therefore the bound is trivial (equal to zero) in the odd case N=2m+1.
Let f be an arbitrary normalized symmetric operator monotone function and let 〈⋅,⋅〉
ρ,f
be the associated quantum Fisher information. Based on previous results of several authors, we propose here as a conjecture
the inequality
whose validity would give a non-trivial bound for any N∈ℕ using the commutators i[ρ,A
h
]. 相似文献
63.
Asymptotic results for weighted means of linear combinations of independent Poisson random variables
Rita Giuliano Claudio Macci 《Stochastics An International Journal of Probability and Stochastic Processes》2020,92(4):497-518
ABSTRACT In this paper we prove the large deviation principle for a class of weighted means of linear combinations of independent Poisson distributed random variables, which converge weakly to a normal distribution. The interest in these linear combinations is motivated by the diffusion approximation in Lansky [On approximations of Stein's neuronal model, J. Theoret. Biol. 107 (1984), pp. 631–647] of the Stein's neuronal model (see Stein [A theoretical analysis of neuronal variability, Biophys. J. 5 (1965), pp. 173–194]). We also prove an analogue result for sequences of multivariate random variables based on the diffusion approximation in Tamborrino, Sacerdote, and Jacobsen [Weak convergence of marked point processes generated by crossings of multivariate jump processes. Applications to neural network modeling, Phys. D 288 (2014), pp. 45–52]. The weighted means studied in this paper generalize the logarithmic means. We also investigate moderate deviations. 相似文献
64.
I. Schoolmann 《Mathematische Nachrichten》2020,293(8):1591-1612
65.
Tianxuan Miao 《Proceedings of the American Mathematical Society》1998,126(12):3571-3579
Let be a -compact locally compact nondiscrete group and let be a -invariant ideal of . We denote the set of left invariant means on that are zero on (i.e. for all ) by . We show that, when is amenable as a discrete group and the closed -invariant subset of the spectrum of corresponding to is a -set, is very large in the sense that every nonempty -subset of contains a norm discrete copy of , where is the Stone- compactification of the set of positive integers with the discrete topology. In particular, we prove that has no exposed points in this case and every nonempty -subset of the set of left invariant means on contains a norm discrete copy of .
66.
We derive differential inequalities and difference inequalities for Riesz means of eigenvalues of the Dirichlet Laplacian,
67.
In this paper, a class C1 of risk measures, which generalizes the class of risk measures for the right-tail deviation suggested by Wang [Wang, S., 1998. An actuarial index of the right-tail risk. North Amer. Actuarial J. 2, 88–101], is characterized in terms of dispersive order. If dispersive order does not hold, unanimous comparisons are still possible by restricting our attention to a subclass C2C1 and then the criterion is the excess-wealth order. Sufficient conditions for stochastic equivalence of excess-wealth ordered random variables are derived in terms of some particular measures of C2. 相似文献
68.
A matrix approach to approximating solutions of variational inequalities in Hilbert spaces is introduced. This approach uses two matrices: one for iteration process and the other for regularization. Ergodicity and convergence (both weak and strong) are studied. Our methods combine new or well-known iterative methods (such as the original Mann’s method) with regularized processes involved regular matrices in the sense of Toeplitz. 相似文献
69.
《数学物理学报(B辑英文版)》1999,19(5):497-504
This paper presents a new type of interpolation of Ba spaces, with which a new characterization of Ba spaces by the Jackson means of entire exponential type is given. 相似文献
70.