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311.
主要讨论一类具有星形结点的平面四次多项式微分系统的全局结构,用系统的积分直线把相平面分成四类扇形区域,根据系统的有限远奇点的情况,给出了相应的实例及其全局结构。 相似文献
312.
We consider three basic graph parameters, the node‐independence number, the path node‐covering number, and the size of the kernel, and study their distributional behavior for an important class of random tree models, namely the class of simply generated trees, which contains, e.g., binary trees, rooted labeled trees, and planted plane trees, as special instances. We can show for simply generated tree families that the mean and the variance of each of the three parameters under consideration behave for a randomly chosen tree of size n asymptotically ~μn and ~νn, where the constants μ and ν depend on the tree family and the parameter studied. Furthermore we show for all parameters, suitably normalized, convergence in distribution to a Gaussian distributed random variable. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009 相似文献
313.
Pedro González‐Casanova José Antonio Muñoz‐Gómez Gustavo Rodríguez‐Gómez 《Numerical Methods for Partial Differential Equations》2009,25(6):1482-1501
During the last years, there has been increased interest in developing efficient radial basis function (RBF) algorithms to solve partial differential problems of great scale. In this article, we are interested in solving large PDEs problems, whose solution presents rapid variations. Our main objective is to introduce a RBF dynamical domain decomposition algorithm which simultaneously performs a node adaptive strategy. This algorithm is based on the RBFs unsymmetric collocation setting. Numerical experiments performed with the multiquadric kernel function, for two stationary problems in two dimensions are presented. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009 相似文献
314.
李毅夫 《数学的实践与认识》2009,39(23)
克服了以往成果中对余弦型振荡函数进行Gauss积分的一些缺点,对余弦型振荡函数的Gauss积分的做了进一步的探讨. 相似文献
315.
A unified a posteriori error analysis has been developed in [18, 21-23] to analyze the finite element error a posteriori under a universal roof. This paper contributes to the finite element meshes with hanging nodes which are required for local mesh-refining. The twodimensional 1-irregular triangulations into triangles and parallelograms and their combinations are considered with conforming and nonconforming finite element methods named after or by Courant, Q1, Crouzeix-Raviart, Poisson, Stokes and Navier-Lamé equations Han, Rannacher-Turek, and others for the The paper provides a unified a priori and a posteriori error analysis for triangulations with hanging nodes of degree ≤ 1 which are fundamental for local mesh refinement in self-adaptive finite element discretisations. 相似文献
316.
Since many large real networks tend to present scale-free degree distribution, this paper investigates the structural properties of scale-free networks with finite size. Beginning with a comprehensive analysis of the degree distribution consisting of the concentration trend, dispersion and inequality, this paper then focuses on the discussion of heterogeneity and hub nodes of scale-free networks. The findings will help to improve our understanding of the structure and function of real networks. 相似文献
317.
Identifying the most influential nodes in complex networks provides a strong basis for understanding spreading dynamics and ensuring more efficient spread of information. Due to the heterogeneous degree distribution, we observe that current centrality measures are correlated in their results of nodes ranking. This paper introduces the concept of all-around nodes, which act like all-around players with good performance in combined metrics. Then, an all-around distance is presented for quantifying the influence of nodes. The experimental results of susceptible-infectious-recovered (SIR) dynamics suggest that the proposed all-around distance can act as a more accurate, stable indicator of influential nodes. 相似文献
318.
该文对具有星形结点的平面五次系统的全局结构的拓扑分类应用Ⅰ Ⅳ型区域(见[2]),讨 论了平面五次系统(1)的全局结构的拓扑分类,并得到93种全局结构及其右边多项式系统的判定方法。
相似文献
319.
Honggang Zhang Shaozhi Liu Aili Zheng Prof. Peng Wang Prof. Zhaoke Zheng Prof. Zeyan Wang Prof. Hefeng Cheng Prof. Ying Dai Prof. Baibiao Huang Prof. Yuanyuan Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(15):e202400965
Recently, amorphous materials have gained great attention as an emerging kind of functional material, and their characteristics such as isotropy, absence of grain boundaries, and abundant defects are very likely to outrun the disadvantages of crystalline counterparts, such as low conductivity, and ultimately lead to improved charge transfer efficiency. Herein, we investigated the effect of amorphization on the charge transfer process and photocatalytic performance with a phosphonate-based metal–organic framework (FePPA) as the research object. Comprehensive experimental results suggest that compared to crystalline FePPA, amorphous FePPA has more distorted metal nodes, which affects the electron distribution and consequently improves the photogenerated charge separation efficiency. Meanwhile, the distorted metal nodes in amorphous FePPA also greatly promote the adsorption and activation of O2. Hence, amorphous FePPA exhibits a better performance of photocatalytic C(sp3)−H bond activation for selective oxidation of toluene to benzaldehyde. This work illustrates the advantages of amorphous MOFs in the charge transfer process, which is conducive to the further development of high performance MOFs-based photocatalysts. 相似文献
320.