全文获取类型
收费全文 | 160篇 |
免费 | 11篇 |
国内免费 | 15篇 |
专业分类
化学 | 8篇 |
力学 | 3篇 |
综合类 | 5篇 |
数学 | 158篇 |
物理学 | 12篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 14篇 |
2011年 | 12篇 |
2010年 | 10篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 15篇 |
2006年 | 4篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有186条查询结果,搜索用时 15 毫秒
1.
S. A. Mohiuddine Tuncer Acar Abdullah Alotaibi 《Mathematical Methods in the Applied Sciences》2017,40(18):7749-7759
In the present paper, we construct a new sequence of Bernstein‐Kantorovich operators depending on a parameter α. The uniform convergence of the operators and rate of convergence in local and global sense in terms of first‐ and second‐order modulus of continuity are studied. Some graphs and numerical results presenting the advantages of our construction are obtained. The last section is devoted to bivariate generalization of Bernstein‐Kantorovich operators and their approximation behaviors. 相似文献
2.
二维正态分布函数值的计算是估算串联结构体系失效概率上、下限的一项重要内容。目前一般常采用两种方法,即数值积分和界限法。前者因计算量大,耗时多不便实用,后者使结构体系失效率的上、下界限进一步变宽。本文给出一个计算二维正态分布函数值的近似方法。实际计算表明,本方法计算效率高,精度完全能满足工程应用要求 相似文献
3.
The stochastic behaviour of lifetimes of a two component system is often primarily influenced by the system structure and by the covariates shared by the components. Any meaningful attempt to model the lifetimes must take into consideration the factors affecting their stochastic behaviour. In particular, for a load share system, we describe a reliability model incorporating both the load share dependence and the effect of observed and unobserved covariates. The model includes a bivariate Weibull to characterize load share, a positive stable distribution to describe frailty, and also incorporates effects of observed covariates. We investigate various interesting reliability properties of this model using cross ratio functions and conditional survivor functions. We implement maximum likelihood estimation of the model parameters and discuss model adequacy and selection. We illustrate our approach using a simulation study. For a real data situation, we demonstrate the superiority of the proposed model that incorporates both load share and frailty effects over competing models that incorporate just one of these effects. An attractive and computationally simple cross‐validation technique is introduced to reconfirm the claim. We conclude with a summary and discussion. 相似文献
4.
Mohammad Reza Saeb Yousef Mohammadi Amir Saeid Pakdel Alexander Penlidis 《Macromolecular theory and simulations》2016,25(4):369-382
A Kinetic Monte Carlo (KMC) simulation approach has been adopted in this study to capture evolutionary events in the course of free radical copolymerization, through which batch and starved‐feed semibatch processes are compared. The implementation of the KMC code developed in this work: (i) enables satisfactory control of the molecular weight of the copolymer by tracking the profiles of concentrations of macroradicals, monomers, and polymer as well as degree of polymerization, polydispersity, and chain length distribution; (ii) captures the bivariate distribution of chain length and copolymer composition; (iii) comprehensively tracks and analyzes detailed information on the molecular architecture of the growing chains, thus distinguishing between sequence length and polydispersity of chains produced in batch and starved‐feed semibatch operations; (iv) makes possible the screening of products, based on such details as the number and weight fractions of products having different comonomer units located at various positions along the copolymer chains. The aforementioned characteristics are achieved by stochastic calculations through code developed in‐house. This KMC simulator becomes a very useful tool for the development of tailored copolymers through free radical polymerization, with blocks separated with single units of a different type.
5.
We establish various properties for the zero sets of three families of bivariate Hermite polynomials. Special emphasis is given to those bivariate orthogonal polynomials introduced by Hermite by means of a Rodrigues type formula related to a general positive definite quadratic form. For this family we prove that the zero set of the polynomial of total degree n+m consists of exactly n+m disjoint branches and possesses n+m asymptotes. A natural extension of the notion of interlacing is introduced and it is proved that the zero sets of the family under discussion obey this property. The results show that the properties of the zero sets, considered as affine algebraic curves in R2, are completely different for the three families analyzed. 相似文献
6.
J.S. Huang G.D. Lin 《Applied mathematics and computation》2011,218(3):919-923
We investigate the maximum correlation for Sarmanov bivariate distributions with fixed marginals and strengthen the existing results in the literature. The improvement in the maximum correlation is significant. A characterization of the Sarmanov distribution via chi-square divergence is also given. This extends Nelsen [13] result about the Farlie-Gumbel-Morgenstern (FGM) distribution. 相似文献
7.
The single 2 dilation wavelet multipliers in one-dimensional case and single A-dilation (where A is any expansive matrix with integer entries and |detA| = 2) wavelet multipliers in twodimensional case were completely characterized by Wutam Consortium (1998) and Li Z., et al.
(2010). But there exist no results on multivariate wavelet multipliers corresponding to integer expansive dilation matrix
with the absolute value of determinant not 2 in L
2(ℝ2). In this paper, we choose $2I_2 = \left( {{*{20}c}
2 & 0 \\
0 & 2 \\
} \right)$2I_2 = \left( {\begin{array}{*{20}c}
2 & 0 \\
0 & 2 \\
\end{array} } \right) as the dilation matrix and consider the 2I
2-dilation multivariate wavelet Φ = {ψ
1, ψ
2, ψ
3}(which is called a dyadic bivariate wavelet) multipliers. Here we call a measurable function family f = {f
1, f
2, f
3} a dyadic bivariate wavelet multiplier if Y1 = { F - 1 ( f1 [^(y1 )] ),F - 1 ( f2 [^(y2 )] ),F - 1 ( f3 [^(y3 )] ) }\Psi _1 = \left\{ {\mathcal{F}^{ - 1} \left( {f_1 \widehat{\psi _1 }} \right),\mathcal{F}^{ - 1} \left( {f_2 \widehat{\psi _2 }} \right),\mathcal{F}^{ - 1} \left( {f_3 \widehat{\psi _3 }} \right)} \right\} is a dyadic bivariate wavelet for any dyadic bivariate wavelet Φ = {ψ
1, ψ
2, ψ
3}, where [^(f)]\hat f and F
−1 denote the Fourier transform and the inverse transform of function f respectively. We study dyadic bivariate wavelet multipliers, and give some conditions for dyadic bivariate wavelet multipliers.
We also give concrete forms of linear phases of dyadic MRA bivariate wavelets. 相似文献
8.
At present, the methods of constructing vector valued rational interpolation function in rectangular mesh are mainly presented by means of the branched continued fractions. In order to get vector valued rational interpolation function with lower degree and better approximation effect, the paper divides rectangular mesh into pieces by choosing nonnegative integer parameters d1 (0 〈 dl ≤ m) and d2 (0 ≤ d2≤ n), builds bivariate polynomial vector interpolation for each piece, then combines with them properly. As compared with previous methods, the new method given by this paper is easy to compute and the degree for the interpolants is lower. 相似文献
9.
10.