全文获取类型
收费全文 | 135篇 |
免费 | 14篇 |
国内免费 | 32篇 |
专业分类
化学 | 31篇 |
力学 | 2篇 |
数学 | 97篇 |
物理学 | 51篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 16篇 |
2012年 | 12篇 |
2011年 | 13篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 2篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有181条查询结果,搜索用时 15 毫秒
31.
In the last decade, much attention has been focused on examining the nonlocality of various quantum networks, which are fundamental for long-distance quantum communications. In this paper, we consider the nonlocality of any forked tree-shaped network, where each node, respectively, shares arbitrary number of bipartite sources with other nodes in the next “layer”. The Bell-type inequalities for such quantum networks are obtained, which are, respectively, satisfied by all -local correlations and all local correlations, where denotes the total number of nodes in the network. The maximal quantum violations of these inequalities and the robustness to noise in these networks are also discussed. Our network can be seen as a generalization of some known quantum networks. 相似文献
32.
The smoothing algorithms have been successfully applied to solve the symmetric cone complementarity problem (denoted by SCCP), which in general have the global and local superlinear/quadratic convergence if the solution set of the SCCP is nonempty and bounded. Huang, Hu and Han [Science in China Series A: Mathematics, 52: 833–848, 2009] presented a nonmonotone smoothing algorithm for solving the SCCP, whose global convergence is established by just requiring that the solution set of the SCCP is nonempty. In this paper, we propose a new nonmonotone smoothing algorithm for solving the SCCP by modifying the version of Huang-Hu-Han’s algorithm. We prove that the modified nonmonotone smoothing algorithm not only is globally convergent but also has local superlinear/quadratical convergence if the solution set of the SCCP is nonempty. This convergence result is stronger than those obtained by most smoothing-type algorithms. Finally, some numerical results are reported. 相似文献
33.
Let H be an infinite-dimensional complex Hilbert space and (H)the algebra of all bounded linear operators on H. Some characterizationsare obtained of linear maps on (H) preserving essential spectralfunctions such as the intersection of left essential spectrumand right essential spectrum of operators, preserving Fredholmoperators, and preserving semi-Fredholm operators, and preservingcloseness of operator ranges. A result of Mbekhta, Rodman andemrl (Integral Equations Operator Theory 55 (2006) 93-109) ongeneralized invertibility preserving linear maps is improved. 相似文献
34.
Jingyong Tang Li Dong Liang Fang Jinchuan Zhou 《Journal of Applied Mathematics and Computing》2013,43(1-2):307-328
The symmetric cone complementarity problem (denoted by SCCP) is a broad class of optimization problems, which contains the semidefinite complementarity problem, the second-order cone complementarity problem, and the nonlinear complementarity problem. In this paper we first extend the smoothing function proposed by Huang et al. (Sci. China 44:1107–1114, 2001) for the nonlinear complementarity problem to the context of symmetric cones and show that it is coercive under suitable assumptions. Based on this smoothing function, a smoothing-type algorithm, which is a modified version of the Qi-Sun-Zhou method (Qi et al. in Math. Program. 87:1–35, 2000), is proposed for solving the SCCP. By using the theory of Euclidean Jordan algebras, we prove that the proposed algorithm is globally and locally quadratically convergent under suitable assumptions. Preliminary numerical results for some second-order cone complementarity problems are reported which indicate that the proposed algorithm is effective. 相似文献
35.
In this paper, we identify a favorable class of nonsmooth functions for which local weak sharp minima can be completely characterized in terms of normal cones and subdifferentials, or tangent cones and subderivatives, or their mixture in finite-dimensional spaces. The results obtained not only extend previous ones in the literature, but also allow us to provide new types of criteria for local weak sharpness. Applications of the developed theory are given to semi-infinite programming and to a new class of semi-infinite complementarity problems. 相似文献
36.
Let be a complex Hilbert space, be the algebra of all bounded linear operators on , be the subset of all selfadjoint operators in and or . Denote by the numerical radius of . We characterize surjective maps that satisfy for all without the linearity assumption.
37.
SPECTRUM-PRESERVING ELEMENTARY OPERATORS ON B(X) 总被引:4,自引:0,他引:4
Hou Jinchuan 《数学年刊B辑(英文版)》1998,19(4):511-516
1.IntroductionLetXbeaninfinitedimensionalcomplexBanachspaceandB(X)theBanachalgebraofallboundedlinearoperatorsonX.ForTEB(X),a(T),asusual,willdenotethespectrumofT.Let4bealinearmapfromB(X)intoitself.4isspectrum-preservingifa(di(T))=a(T)forallTEB(X);4isspectrum-compressingifa(4(T))ga(T)forallTEB(X).Itisclearthatif4isunital(i.e.,ac(I)=I),thenacisspectrum-preserving(spectrum-compressing)ifandonlyif4preservesinvertibilityinbothdirections(preservesinvertibility),i.e.,4(T)isinvertibleifando… 相似文献
38.
39.
研究了成像板辐射图像测量的基本原理及其物理机制,并将其应用于伽马图像测量。建立了MS,SR和TR三种类型成像板数值模拟模型,分别使用MCNPX程序和基于Geant4开发的NPE程序计算了三种成像板对不同能量伽马射线的能量沉积,计算结果表明:SR和MS成像板比TR成像板能量沉积在低能部分大3~5倍,高能部分大7~9倍。实验测量了MS成像板灵敏度随铜膜厚度的变化关系,测量结果与理论计算结果有较好的一致性。理论与实验结果表明:成像板伽马图像测量的空间分辨力优于50 m。 相似文献
40.
以去氢枞酸为原料,通过不同的长度碳链与硫化氢供体4-羟基硫代苯甲酰胺偶联,合成了5个新型硫化氢供体型去氢枞酸衍生物,所得化合物结构经1H NMR、 13C NMR和HR-MS表征。以阿霉素为阳性对照药,采用MTT法测定目标化合物对HepG2、 MGC803、 T24、 A549和LO2的细胞抑制作用。结果表明:大部分化合物对4种肿瘤细胞株的抑制活性优于母体化合物去氢枞酸,其中化合物4c对HepG2、 T24和A549细胞株的IC50值分别为4.63±0.18、 6.06±0.49和5.79±0.14 μmol·L-1,优于或接近阳性对照药阿霉素(5.44±0.87、 3.69±0.78和3.75±0.11μmol·L-1)。 相似文献