检索结果-南通市图书馆

Chinese Physics B 2014年第2期23卷 80-86页

作者：廖湘萍方卯发方见树朱钱泉 College of Science Hunan University of Technology College of Physics and Information Science Hunan Normal University

We demonstrate a method to preserve entanglement and improve fidelity of three-qubit quantum states undergoing amplitude-damping decoherence using weak measurement and quantum measurement reversal. It is shown that we are able to enhance entanglement to the greatest extent, and to circumvent entanglement sudden death by increasing the weak measurement strength both for the GHZ state and the W state. The weak measurement technique can also enhance the fidelity to the quantum region and even close to 1 for the whole range of the decoherence parameter in both of the two cases. In addition, the W state can maintain more fidelity than the GHZ state in the protection protocol. However, the GHZ state has a higher success probability than the W state.

关键词： entanglement protection quantum fidelity weak measurement

Feasible synthesis of porous h-BN by Mg^(2+)induced lattice dislocations for hydrogen and ammonia storage

在线全文

学校读者我要写书评

暂无评论

Nano Research 2025年第1期18卷 94-99页

作者： Xiaojia Huang Zihao Wang Yihan Kong Li Jiang Baolin Wang Jiangtao Jia Heping Ma Guangshan Zhu Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Northeast Normal UniversityChangchun 130024China School of Chemical Engineering and Technology Xi’an Jiaotong university Xi’an 710049China

Hexagonal boron nitride(h-BN)is a two-dimensional(2D)layered material with a structure similar to graphite and it has potential as a hydrogen and ammonia storage ***,dense packing in the standard h-BN structure limits its surface area and prevents the B and N from being adsorption *** this study,the addition of Mg^(2+)during h-BN synthesis facilitated the growth of lattice dislocations and led to a crosslinked three-dimensional(3D)porous structure.A proposed formation mechanism for porous h-BN was confirmed by several characterization routes,most clearly by high-resolution transmission electron microscopy(HRTEM).Porous Mg/BNs exhibited high H_(2)and NH_(3)uptakes and showed potential for H_(2)and NH_(3)storage.

关键词： hexagonal boron nitride porous material dislocation gas storage

Sudden death and revival of entanglement of two qubits coupled collectively to a thermal reservoir

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第9期19卷 379-385页

作者：廖湘萍方见树方卯发 College of Science Hunan University of Technology College of Physics and Information Science Hunan Normal University

In this paper, we investigate the entanglement of two qubits coupled collectively to a common thermal environment and find that the the collective decay can lead to a revival of the entanglement that has already been destroyed. We also show that the ability of the system to revival entanglement relies on the mean photon number of the thermal environment and the degree of entanglement of the initial state.

关键词： sudden death of entanglement two qubits the thermal reservoir

Hawking Radiation of a d-Dimensional Black Hole with Quantum Correction

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2013年第2期59卷 165-171页

作者：尹芬芬陈松柏 Institute of Physics and Department of Physics Hunan Normal University Quantum Control of Ministry of Education Hunan Normal University

We study the absorption probability and Hawking radiation of the scalar field in a d-dimensional black hole with quantum correction arising from the polymer quantization. We find that the quantum length scale k （i.e., the bounce radius） modifies the standard results in greybody factors and Hawking radiation on the brahe and into the bulk. For the black hole with the larger mass M the effects of the parameter k in the four-dimensional black hole spacetime are entirely different from those in the high dimensional cases. When the mass of black hole M becomes very small, we also find that only the sign of the change rate of the greybody factors on the brahe with respect to the dimensional number depends sharply on the bounce radius k. These information can help us know more about the extra dimension and the black holes with quantum correction.

关键词： Hawking radiation quantum correction black hole

Coherent State of N Components and Cycle Representation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1995年第3期12卷 132-135页

作者： ZENG Gaojian KUANG Leman LI Jinhui Department of Physics Hunan Normal UniversityHunan 410006

In this paper,we construct a type of coherent state with N components,and use it to span cycle representations of the Lie algebras SU(2),SU(1,l)and the Lit:superalgebra OSP(1,2).The method for constructing cycle repre... 详细信息

关键词： cycle constructing coherent

Identification of differential brain regions in MCI progression via clustering-evolutionary weighted SVM ensemble algorithm

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2021年第6期15卷 165-173页

作者： Xia-an BI Yiming XIE Hao WU Luyun XU hunan Provincial Key Laboratory of Intelligent Computing and Language Information Processing Hunan Normal UniversityChangsha 410081China College of Information Science and Engineering Hunan Normal UniversityChangsha 410081China Business School of hunan normal university Changsha 410081China

Mild cognitive impairment(MCI)as the potential sign of serious cognitive decline could be divided into two stages,i.e.,late MCI(LMCI)and early MCI(EMCI).Although the different cognitive states in the MCI progression have been clinically defined,effective and accurate identification of differences in neuroimaging data between these stages still needs to be further *** this paper,a new method of clustering-evolutionary weighted support vector machine ensemble(CEWSVME)is presented to investigate the alterations from cognitively normal(CN)to EMCI to *** CEWSVME mainly includes two *** first step is to build multiple SVM classifiers by randomly selecting samples and *** second step is to introduce the idea of clustering evolution to eliminate inefficient and highly similar SVMs,thereby improving the final classification ***,we extracted the optimal features to detect the differential brain regions in MCI progression,and confirmed that these differential brain regions changed dynamically with the development of *** exactly,this study found that some brain regions only have durative effects on MCI progression,such as parahippocampal gyrus,posterior cingulate gyrus and amygdala,while the superior temporal gyrus and the middle temporal gyrus have periodic effects on the *** work contributes to understanding the pathogenesis of MCI and provide the guidance for its timely diagnosis.

关键词： machine learning MCI progression optimal feature extraction differential brain regions functional magnetic resonance imaging

Orbital effect in the stationary axisymmetric field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第7期17卷 2356-2360页

作者：龚添喜王永久 Institute of Physics Hunan Normal University School of Physics Hunan University of Science and Technology

This paper uses an elegant mathematical method to calculate the orbital effects in the axisymmetric field created by the spinning mass with electric charge and a large number of magnetic monopoles. In comparison with that in the Reissner-Nordstroem （R-N） field, the correction terms caused by the spinning mass decrease the advanced effect as the revolution direction of the test particle coincides with that of the Kerr field, however, the correction terms caused by the spinning charged mass increase the advance effect as the revolution direction of the test particle coincides with that of the Kerr-Newman-Kasnya （KNK） field. Generalizing the effect in the axisymmetric field, it obtains interesting results by discussing the parameters of the celestial body, these parameters provide a feasible experimental verification of the general relativity.

关键词： general relativity gravitational effect space-time metric

On the Category of Koszul Modules of Complexity One of an Exterior Algebra

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2006年第3期22卷 849-854页

作者： Jin Yun GUO Bing Jun LI Qiu Xian WU Department of Mathematics Hunan Normal University

In this paper, we prove that there is a natural equivalence between the category F1（x） of Koszul modules of complexity 1 with filtration of given cyclic modules as the factor modules of an exterior algebra A = ∧V of an m-dimensional vector space, and the category of the finite-dimensional locally nilpotent modules of the polynomial algebra of m - 1 variables.

关键词： exterior algebra Koszul module complexity

DIAGONAL REDUCTION OVER sπr IDEALS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2008年第1期28卷 179-184页

作者：陈焕艮 Department of Mathematics Hunan Normal University

This article introduces a new class of ideals, namely, the sπr ideals. It is shown that every regular square matrix over sπr ideals of a ring admits a diagonal reduction.

关键词： sπr Ideals diagonal reduction stable range one

THRESHOLD RESULT FOR SEMILINEAR PARABOLIC EQUATIONS WITH INDEFINITE NON-HOMOGENEOUS TERM

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2012年第6期32卷 2302-2314页

作者：谢君辉戴求亿刘芳 Department of Mathematics Hunan Normal University

In this paper, we study the threshold result for the initial boundary value problem of non-homogeneous semilinear parabolic equations {μt-△μ=g（μ）＋λf（x）,（x,t）∈Ω×（0,T）,μ=0,（x,t）∈ Ω×[0,T）,μ（x,0）=μ0（x）≥0,x∈Ω.By combining a priori estimate of global solution with property of stationary solution set of problem （P）, we prove that the minimal stationary solution Uλ（x） of problem （P） is stable, whereas, any other stationary solution is an initial datum threshold for the existence and nonexistence of global solution to problem （P）.

关键词： parabolic equations initial boundary value problem global solution thresh-old result non-homogenous tern: