全文获取类型
收费全文 | 2858篇 |
免费 | 533篇 |
国内免费 | 325篇 |
专业分类
化学 | 20篇 |
晶体学 | 1篇 |
力学 | 620篇 |
综合类 | 159篇 |
数学 | 2391篇 |
物理学 | 525篇 |
出版年
2024年 | 38篇 |
2023年 | 31篇 |
2022年 | 44篇 |
2021年 | 54篇 |
2020年 | 55篇 |
2019年 | 51篇 |
2018年 | 37篇 |
2017年 | 44篇 |
2016年 | 54篇 |
2015年 | 63篇 |
2014年 | 139篇 |
2013年 | 97篇 |
2012年 | 113篇 |
2011年 | 158篇 |
2010年 | 204篇 |
2009年 | 218篇 |
2008年 | 168篇 |
2007年 | 186篇 |
2006年 | 131篇 |
2005年 | 199篇 |
2004年 | 156篇 |
2003年 | 167篇 |
2002年 | 136篇 |
2001年 | 134篇 |
2000年 | 119篇 |
1999年 | 100篇 |
1998年 | 103篇 |
1997年 | 135篇 |
1996年 | 86篇 |
1995年 | 99篇 |
1994年 | 67篇 |
1993年 | 59篇 |
1992年 | 65篇 |
1991年 | 76篇 |
1990年 | 57篇 |
1989年 | 52篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
排序方式: 共有3716条查询结果,搜索用时 15 毫秒
101.
We present a novel perspective on characterizing the spectral correspondence between nodes of the weighted graph with application to image registration. It is based on matrix perturbation analysis on the spectral graph. The contribution may be divided into three parts. Firstly, the perturbation matrix is obtained by perturbing the matrix of graph model. Secondly, an orthogonal matrix is obtained based on an optimal parameter, which can better capture correspondence features. Thirdly, the optimal matching matrix is proposed by adjusting signs of orthogonal matrix for image registration. Experiments on both synthetic images and real-world images demonstrate the effectiveness and accuracy of the proposed method. 相似文献
102.
据2008年9月27日美国Science News报道:9月3日费米实验室的Dzero探测器发言人DmitriDenisov宣布,他们发现了一个由底夸克和围绕着它旋转的两个奇异夸克组成的奇异粒子,该粒子被命名为Ωb-(Omega-b-minus).这是继1964.年发现由3个奇异夸克组成的奇异粒子后,又一个符合粒子物理标准模型所预见的粒子.美国斯坦福直线加速器中心的物理学家Michael Peskin誉此发现为装饰在美妙理论桂冠上的又一根羽毛. 相似文献
103.
MA Hong-Cai YU Yao-Dong GE Dong-Jie 《理论物理通讯》2009,51(4):609-612
In this paper, the nonlinear dispersive Zakharov- Kuznetsov equation is solved by using the generalized auxiliary equation method. As a result, new solitary pattern, solitary wave and singular solitary wave solutions are found. 相似文献
104.
Perturbation to Unified Symmetry and Adiabatic Invariants for Relativistic Hamilton Systems 总被引:1,自引:0,他引:1
ZHANG Ming-Jiang FANG Jian-Hui LU Kai PANG Ting LIN Peng 《理论物理通讯》2009,51(6):961-966
Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the system is presented, and the criterion of the perturbation to unified symmetry is given. Meanwhile, the Noether adiabatic invariants, the generalized Hojman adiabatic invariants, and the Mei adiabatic invariants for the perturbed system are obtained. 相似文献
105.
Variational iteration method for solving perturbed mechanism of western boundary undercurrents in the Pacific 总被引:9,自引:0,他引:9
下载免费PDF全文

A class of perturbed mechanisms for the western boundary
undercurrents in the Pacific is considered. The model of generalized
governing equations is studied. Employing the method of variational
iteration, an approximate solution of corresponding model is
obtained. It is proved from the results that the solution for the
variational iteration method can be used for analysing operation of
the perturbed mechanism of western boundary undercurrents in the
Pacific. 相似文献
106.
Singular value decomposition with normalized period for magnetocaridiography signal processing
下载免费PDF全文

In this paper, we have developed an algorithm based on singular value
decomposition (SVD) for matrix. And the novel SVD algorithm with normalized
period of cardiac cycles is presented. The results from real
magnetocardiography (MCG) data processing show that the new algorithm is
better than the standard one not only in suppressing noises, but also in
providing high-fidelity MCG signals. 相似文献
107.
108.
A perturbation method is applied to study the structure of the ground state of the adiabatic quantum optimization for the exact cover 3 problem. It is found that the instantaneous ground state near the end of the evolution is mainly composed of the eigenstates of the problem Hamiltonian, which are Hamming close to the solution state. And the instantaneous ground state immediately after the starting is mainly formed of low energy eigenstates of the problem Hamiltonian. These results are then applied to estimate the minimum gap for a special case. 相似文献
109.
系统地研究了相对论夸克模型框架下的底奇异介子的辐射衰变。给出了底奇异介子E1 和M1 辐射衰变分宽度。这些结果表明,大多数电偶极辐射衰变宽带能达到数个keV,大多数磁偶极辐射衰变宽度小于1 个keV,这为实验上通过辐射衰变寻找底奇异介子提供了理论依据。建设中的Belle II 上的实验可以进一步验证我们的结果。We systematically study the radiative transitions of bottom-strange mesons in the framework of the relativistic constituent quark model. The partial widths of the E1 and M1 decays are predicted. The results predict that most of E1 decay widths are several keV and most of M1 decay widths are less than 1 keV,which give a roadmap of searching for the higher bottom-strange mesons via radiative decays. The experimental searches by the forthcoming Belle II can in turn provide further tests to our result in the present work. 相似文献
110.
采用相对论和非相对论理论模型可描述奇异核的性质 .相对论平均场理论预言了2 6,2 7,2 8P存在一个质子晕 ,而27,28,29S存在两个质子晕 .最近 ,MSU的最新的实验发现了2 6,2 7,2 8P核存在一个质子晕.采用相对论 Hartree- Fock理论研究了 Fock项和矢量介子对奇异核性质的贡献,研究表明交换项和矢量介子对非常丰中子核性质的影响非常不同于对稳定线附近核性质的影响.同时,采用形变的Hartree- Fock- Bogoliubov理论研究了某些轻核同位素链的性质和形变. 相似文献