全文获取类型
收费全文 | 558篇 |
免费 | 33篇 |
国内免费 | 15篇 |
专业分类
化学 | 56篇 |
晶体学 | 3篇 |
力学 | 153篇 |
综合类 | 3篇 |
数学 | 292篇 |
物理学 | 99篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 13篇 |
2021年 | 7篇 |
2020年 | 13篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 23篇 |
2016年 | 10篇 |
2015年 | 18篇 |
2014年 | 23篇 |
2013年 | 49篇 |
2012年 | 22篇 |
2011年 | 47篇 |
2010年 | 41篇 |
2009年 | 28篇 |
2008年 | 34篇 |
2007年 | 37篇 |
2006年 | 26篇 |
2005年 | 23篇 |
2004年 | 22篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 10篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有606条查询结果,搜索用时 0 毫秒
591.
In this paper, we present second-order optimality conditions for convex composite minimization problems in which the objective function is a composition of a finite-valued or a nonfinite-valued lower semicontinuous convex function and aC
1,1 function. The results provide optimality conditions for composite problems under reduced differentiability requirements.This paper is a revised version of the Departmental Preliminary Report AM92/32, School of Mathematics, University of New South Wales, Kensington, NSW, Australia.Research of this author was supported in part by an Australian Research Council Grant. 相似文献
592.
一种高效的等参有限元逆变换算法 总被引:24,自引:3,他引:24
采用Taylor展开技术构造了一种具有线性迭代格式的等参有限元逆变换算法,对算法的收敛性和收敛速度分别给出了理论证明和数值检验。该算法不仅形式简单、便于程序实现,且适合于任何类型的等参单元,是一种高效实用的逆变换算法。文中还给出了算法的实施框图。 相似文献
593.
为了研究调整架角度误差以及波片与光源波长不匹配对线偏振光经过1/4波片之后偏振态的影响,本文利用坐标变换法得到1/4波片的琼斯矩阵,并用琼斯矩阵表示各偏振态。推导出波片与光源不匹配时对偏振态的影响理论模型。当考虑到调整架的角度误差时,对入射光偏振态以及波片的琼斯矩阵表达式做引入角度误差的泰勒展开,最后得到和实验结果匹配的仿真曲线。仿真结果表明,当采用808 nm 1/4波片对795 nm波长的线偏振光作用时,在不考虑调整误差的理想情况下出射光椭圆度最高为0.9746,考虑调整误差时,对应理想情况下椭圆度最高为0.96,椭圆度最高点偏移1.72°。仿真和实验结果为进一步分析泵浦光椭圆度对原子参数的影响提供了依据。 相似文献
594.
595.
Mihai Deleanu Jean-François Hernandez Hervé Cottet Joseph Chamieh 《Electrophoresis》2023,44(7-8):701-710
The use of fluorescently tagged amyloid peptides, implicated in Alzheimer's disease, to study their aggregation at low concentrations is a common method; however, the fluorescent tag should not introduce a bias in the aggregation process. In this work, native amyloid peptides Aβ(1–40) and Aβ(1–42) and fluorescein-5-isothiocyanate (FITC), tagged ones, were studied using Taylor dispersion analysis coupled with a simultaneous UV and light-emitting diode-induced fluorescence detection, to unravel the effect of FITC on the aggregation process. For that, a total concentration of 100 µM of peptides consisting of a mixture of native and tagged ones (up to 10% in moles) was applied. Results demonstrated that FITC had a strong inhibition effect upon the aggregation behaviour of Aβ(1–42), whereas for Aβ(1–40), only a retardation in kinetics was observed. It was also shown that when mixed solutions of Aβ(1–40) and Aβ(1–42) are used, the Aβ(1–42) alloform was the leading peptide in the aggregation process, and when the latter was tagged, the aggregation kinetics decreased but the lifetime of potentially toxic oligomers was drastically increased. These results confirmed that the hydrophilicity of the N-terminus part of the peptide plays a major role in the aggregation process. 相似文献
596.
Mustafa Gü lsu Yalç ın Ö ztü rk & Ayşe Anapali 《advances in applied mathematics and mechanics.》2013,5(6):872-884
In this article, we have introduced a Taylor collocation method,
which is based on collocation method for solving fractional Riccati
differential equation. The fractional derivatives are described in
the Caputo sense. This method is based on first taking the truncated
Taylor expansions of the solution function in the fractional Riccati
differential equation and then substituting their matrix forms into
the equation. Using collocation points, the systems of nonlinear
algebraic equation are derived. We further solve the system of
nonlinear algebraic equation using Maple 13 and thus obtain the
coefficients of the generalized Taylor expansion. Illustrative
examples are presented to demonstrate the effectiveness of the
proposed method. 相似文献
597.
598.
Pallop Huabsomboon Hideaki Kaneko 《Journal of Computational and Applied Mathematics》2010,234(5):1466-1472
In this paper, we comment on the recent papers by Yuhe Ren et al. (1999) [1] and Maleknejad et al. (2006) [7] concerning the use of the Taylor series to approximate a solution of the Fredholm integral equation of the second kind as well as a solution of a system of Fredholm equations. The technique presented in Yuhe Ren et al. (1999) [1] takes advantage of a rapidly decaying convolution kernel k(|s−t|) as |s−t| increases. However, it does not apply to equations having other types of kernels. We present in this paper a more general Taylor expansion method which can be applied to approximate a solution of the Fredholm equation having a smooth kernel. Also, it is shown that when the new method is applied to the Fredholm equation with a rapidly decaying kernel, it provides more accurate results than the method in Yuhe Ren et al. (1999) [1]. We also discuss an application of the new Taylor-series method to a system of Fredholm integral equations of the second kind. 相似文献
599.
In this paper, we consider a one-dimensional nonlinear partial differential equation that has the form ut + αuux + βunux - γuxx + δuxxx = F(u). A higher order lattice Bhatnager-Gross-Krook (BGK) model with an amending-function is proposed. With the Chapman-Enskog expansion, different kinds of nonlinear partial differential equations are recovered correctly from the continuous Boltzmann equation. The numerical results show that this method is very effective. 相似文献
600.
Let R and S be commuting n-tuples of operators. We will give some spectral relations between RS and SR that extend the case of single operators. We connect the Taylor spectrum, the Fredholm spectrum and some other joint spectra of RS and SR. Applications to Aluthge transforms of commuting n-tuples are also provided. 相似文献