期刊文献+
共找到25篇文章
< 1 2 >
每页显示 20 50 100
Matrix elements in the SU(1,1)⊗SO(6)limit of the proton-neutron symplectic model 被引量:1
1
作者 H.G.Ganev 《Chinese Physics C》 SCIE CAS CSCD 2021年第11期101-114,共14页
The matrix elements along the reduction chain Sp(12,R)⊃SU(1,1)⊗SO(6)⊃U(1)⊗SUpn(3)⊗SO(2)⊃SO(3)of the proton-neutron symplectic model(PNSM)are considered.Closed analytical expressions are obtained for the matrix element... The matrix elements along the reduction chain Sp(12,R)⊃SU(1,1)⊗SO(6)⊃U(1)⊗SUpn(3)⊗SO(2)⊃SO(3)of the proton-neutron symplectic model(PNSM)are considered.Closed analytical expressions are obtained for the matrix elements of the basic building blocks of the PNSM and the Sp(12,R)symplectic generators,allowing the computation of matrix elements of other physical operators as well.The computational technique developed in the present study generally provides us with the required algebraic tool for performing realistic symplectic-based shell-model calculations of nuclear collective excitations.Utilizing two simple examples,we illustrate the application of the theory. 展开更多
关键词 matrix elements proton-neutron symplectic model SU(1 1)⊗SO(6)limit Sp(12 R)dynamical algebra
原文传递
Research on convergence of the nuclear matrix elements for 2νββ decays
2
作者 胡玥 李瀚涛 董成伟 《Chinese Physics C》 SCIE CAS CSCD 2020年第12期171-176,共6页
In this work,the characteristics of 2νββ decays for six nuclei(36Ar,46Ca,48Ca,50Cr,70Zn,and 136Xe)in a mass range from A=36 to A=136 are studied within the nuclear shell model(NSM)framework.Calculations are present... In this work,the characteristics of 2νββ decays for six nuclei(36Ar,46Ca,48Ca,50Cr,70Zn,and 136Xe)in a mass range from A=36 to A=136 are studied within the nuclear shell model(NSM)framework.Calculations are presented for the half-lives,nuclear matrix elements(NMEs),phase space factors(G2ν),and convergence of the NMEs.The theoretical results agree well with the experimental data.In addition,we predict the half-lives of 2νββ decays for four nuclei.We focus on the convergence of the NMEs by analyzing the number of contributing intermediate 1+states(NC)for the nuclei of interest.We assume that NC is safely determined when the accumulated NMEs saturate 99.7%of the final calculated magnitude.From the calculations of the involved nuclei,we discover a connection between NC and the total number of intermediate 1+states(NT).According to the least squares fit,we conclude that the correlation is NC=(10.8±1.2)×N(0.29±0.02)T. 展开更多
关键词 two-neutrino double beta decay nuclear matrix elements CONVERGENCE
原文传递
THE DYNAMIC STIFFNESS MATRIX OF THE FINITE ANNULAR PLATE ELEMENT
3
作者 张益松 高德平 吴晓萍 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第12期1151-1162,共12页
The dynamic deformation of harmonic vibration is used as the shape functions of the finite annular plate element, and sonic integration difficulties related to the Bessel's functions are solved in this paper. Then... The dynamic deformation of harmonic vibration is used as the shape functions of the finite annular plate element, and sonic integration difficulties related to the Bessel's functions are solved in this paper. Then the dynamic stiffness matrix of the finite annular plate element is established in closed form and checked by the direct stiffness method. The paper has given wide convcrage for decomposing the dynamic matrix into the power series of frequency square. By utilizing the axial symmetry of annular elements, the modes with different numbers of nodal diameters at s separately treated. Thus some terse and complete results are obtained as the foundation of structural characteristic analysis and dynamic response compulation. 展开更多
关键词 DE THE DYNAMIC STIFFNESS matrix OF THE FINITE ANNULAR PLATE ELEMENT PING
下载PDF
THE GENERATION OF NON-LINEAR STIFFNESS MATRIX OF TRIANGLE ELEMENT WHENCONSIDERING BOTH THE BENDING AND IN-PLANEME MBRANE FORCES
4
作者 张建海 李永年 陈大鹏 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第5期425-434,共10页
Using Stricklin Melhod ̄[5],we have this paper has derived the formulas for the ge-neration of non-linear element stiffness matrix of a triangle element when considering both the bending and the in-plane membrane forc... Using Stricklin Melhod ̄[5],we have this paper has derived the formulas for the ge-neration of non-linear element stiffness matrix of a triangle element when considering both the bending and the in-plane membrane forces. A computer programme for the calculation of large deflection and inner forces of shallow shells is designed on theseformulas. The central deflection curve computed by this programme is compared with other pertaining results. 展开更多
关键词 triangular element non-linear stiffness matrix
下载PDF
Non Degeneration of Fibonacci Series, Pascal’s Elements and Hex Series
5
作者 Balasubramani Prema Rangasamy 《Advances in Pure Mathematics》 2020年第7期393-404,共12页
Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I ex... Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I explored the inter relations of Fibonacci series when I was intent on Fibonacci series in my difference parallelogram. In which, I found there is no degeneration on Fibonacci series. In my thought, Pascal triangle seemed like a lower triangular matrix, so I tried to find the inverse for that. In inverse form, there is no change against original form of Pascal elements matrix. One day I played with ring magnets, which forms hexagonal shapes. Number of rings which forms Hexagonal shape gives Hex series. In this paper, I give the general formula for generating various types of Fibonacci series and its non-degeneration, how Pascal elements maintain its identities and which shapes formed by hex numbers by difference and matrices. 展开更多
关键词 Fibonacci Series Lucas Series Golden Ratio Various Type of Fibonacci Series Generated by Matrices matrix Operations on Pascal’s elements and Hex Numbers
下载PDF
Magic wavelengths for 6s_(1/2)→5d_(3/2,5/2)transitions of Yb~+ions
6
作者 陈婷 吴磊 +3 位作者 张儒奎 唐永波 蒋军 董晨钟 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期405-412,共8页
The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabiliti... The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabilities of the ground state and low-lying excited states are determined.Then,the magic wavelengths of the magnetic sublevel 6s_(1/2,m=1/2)→5d_(3/2,m=±3/2,±1/2)and 6s_(1/2,m=1/2)→5_(d5/2,m=±5/2,±3/2,±1/2)transitions in the linearly,right-handed,and left-handed polarized light are further determined.The dependence of the magic wavelengths upon the angle between the direction of magnetic field and the direction of laser polarization is analyzed. 展开更多
关键词 matrix elements POLARIZABILITIES magic wavelengths relativistic configuration interaction plus core polarization(RCICP)method
下载PDF
Variational Calculations for (ns2) 1Se, (np2) 1De and (nd2) 1Ge Resonance States for He Isoelectronic Sequences below the n = 2, 3 and 4 Hydrogenic Thresholds
7
作者 Matabara Dieng 《Journal of Modern Physics》 2023年第12期1617-1633,共17页
This work presents results of the different parameters which characterize the nonrelativistic Hamilton operator for the helium atoms allowing us to solve the Schrödinger equation. The total energy is decomposed i... This work presents results of the different parameters which characterize the nonrelativistic Hamilton operator for the helium atoms allowing us to solve the Schrödinger equation. The total energy is decomposed into three terms allowing to separate the kinetic energy, the electrons-nucleus interaction energy and the electron-electron interaction energy of the (2s<sup>2</sup>, 3s<sup>2</sup> and 4s<sup>2</sup>) <sup>1</sup>S<sup>e</sup>, (2p<sup>2</sup>, 3p<sup>2</sup> and 4p<sup>2</sup>) <sup>1</sup>D<sup>e</sup> and (3d<sup>2</sup> and 4d<sup>2</sup>) <sup>1</sup>G<sup>e</sup> resonance singlet states of the helium isoelectronic sequences. The states have been defined by using special forms of the Hylleraas type wave functions. The calculations have been carried out in the framework of the variational method using configuration interaction basis states with a real Hamiltonian. The agreement of the energy value of other states between the present theoretical values available in the literature is excellent. But as for the comparison of the kinetic energies, the electrons-nucleus energies interaction and the electron-electron interaction energies, we note a slight difference with the theoretical values common in literature. 展开更多
关键词 Hylleraas Method Helium-Like Ions Systems Singlet Doubly-Excited States matrix elements AUTOIONIZATION
下载PDF
NORMALIZED ELEMENT NODE TOPOLOGICAL MATRIX OF FINITE ELEMENT MESHES
8
作者 Hao Yongping 《Computer Aided Drafting,Design and Manufacturing》 1996年第1期69-74,共2页
On the basis of concept of element node topological analysis, the normalized element node topological matrices for finite element meshes are presented in the paper, including 3-node and 6-node triangular element, 4-n... On the basis of concept of element node topological analysis, the normalized element node topological matrices for finite element meshes are presented in the paper, including 3-node and 6-node triangular element, 4-node and 8-node quadrilateral element, 8-node and 20-node hexahedral element. It is beneficial to further analyzing topological characteristics of finite element models and automatic generation of meshes 展开更多
关键词 ss: element node topological matrix relativity
全文增补中
Rotation and vibration of diatomic molecule oscillator with hyperbolic potential function 被引量:2
9
作者 陆军 钱卉仙 +1 位作者 李良梅 柳凤伶 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第12期2402-2406,共5页
The explicit expressions of energy eigenvalues and eigenfunctions of bound states for a three-dimensional diatomic molecule oscillator with a hyperbolic potential function are obtained approximately by means of the hy... The explicit expressions of energy eigenvalues and eigenfunctions of bound states for a three-dimensional diatomic molecule oscillator with a hyperbolic potential function are obtained approximately by means of the hypergeometric series method. Then for a one-dimensional system, the rigorous solutions of bound states are solved with a similar method. The eigenfunctions of a one-dimensional diatomic molecule oscillator, expressed in terms of the Jacobi polynomial, are employed as an orthonormal basis set, and the analytic expressions of matrix elements for position and momentum operators are given in a closed form. 展开更多
关键词 diatomic molecule hyperbolic potential matrix elements
下载PDF
Energy Positions of the <sup>1,3</sup>D<sup>e</sup>Rydberg Series of the He-Like Ions Up to the <i>N</i>= 9 Threshold
10
作者 Matabara Dieng Babou Diop +4 位作者 Malick Sow Youssou Gning Mamadi Biaye Ababacar Sadikhe Ndao Ahmadou Wagué 《Journal of Applied Mathematics and Physics》 2020年第8期1535-1549,共15页
The <img alt="" src="Edit_a001991b-d72d-4ec7-885a-6fd2c587397c.bmp" /> <span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;&qu... The <img alt="" src="Edit_a001991b-d72d-4ec7-885a-6fd2c587397c.bmp" /> <span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">doubly excited states of helium-like ions are investigated using a combination of the no-linear parameters of Hylleraas and the </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-parameters of screening constant by unit nuclear charge. Calculations are performed for total energies of low-lying doubly excited states (</span><i><span style="font-family:Verdana;">N</span></i><span style="font-family:Verdana;"> = 2</span></span><span><span><span><span> </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span></span><span><span><span><span> </span></span></span></span><span><span><span><span><span style="font-family:Verdana;">9)</span><i> </i><span style="font-family:Verdana;">in He-like ions up to </span><i><span style="font-family:Verdana;">Z</span></i><span style="font-family:Verdana;"> = 10. The results obtained from the novel method are in good agreement with the available theoretical calculations and experimental observations.</span></span></span></span></span> 展开更多
关键词 Electronic Correlations Variational Calculations Atoms And Ions Helium-Like Systems Singlet States Triplet States matrix elements Doubly-Excited States AUTOIONIZATION
下载PDF
Optimizing the atmospheric sampling sites using fuzzy mathe-matic methods
11
作者 FANG Chun sheng WANG Ju +1 位作者 DONG De ming YU Lian sheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第4期464-468,共5页
A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental samp... A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental sampling sites. According to its basis, an application in the optimization of sampling sites in the atmospheric environmental monitoring was discussed. The method was proven to be suitable and effective. The results were admitted and applied by the Environmental Protection Bureau (EPB) of many cities of China. A set of computer software of this approach was also completely compiled and used. 展开更多
关键词 fuzzy set primary matrix element theorem fisher classification method optimization of sampling sites
下载PDF
Analysis of the decay B^0→χc1~π~0 with light-cone QCD sum rules
12
作者 王志刚 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期3803-3809,共7页
In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic (QCD) sum rules. The numerical results show t... In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic (QCD) sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally. 展开更多
关键词 light-cone QCD sum rule B-decay nonfactorizable hadronic matrix element
下载PDF
Application of Viscoelastic Material in Structures Control
13
作者 魏文辉 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2004年第1期91-93,共3页
The factors influencing mechanical performances of viscoelastic material are studied.The proper finite element model for dynamical calculating the passive control of wind-earthquake resistance is constructed.A combine... The factors influencing mechanical performances of viscoelastic material are studied.The proper finite element model for dynamical calculating the passive control of wind-earthquake resistance is constructed.A combined element stiffness matrix of damper-brace system is deduced.At last,the theoretical deduction is verified by comparing the theoretical results with experimental ones. 展开更多
关键词 ENERGY-DISSIPATION viscoelastic materials element stiffness matrix
下载PDF
Evidence for Non-existence of Oscillations in Photofield Emission Current in Gallium Arsenide
14
作者 R.K.Thapa Nikita Chhetri 《材料科学与工程(中英文A版)》 2022年第3期94-96,共3页
We have shown here the results of PFEC(photofield emission current)calculated for GaAs(gallium arsenide).We have used the initial state wavefunctions derived using the Kronig-Penney potential model for evaluating the ... We have shown here the results of PFEC(photofield emission current)calculated for GaAs(gallium arsenide).We have used the initial state wavefunctions derived using the Kronig-Penney potential model for evaluating the PFEC.We have found that PFEC is not oscillatory as obtained by Modinos and Klient,[Solid State Commun.50,651(1984)],but it is an exponential function. 展开更多
关键词 Photofield emission matrix element Kronig-Penney potential model density of state.
下载PDF
Hypoxia-controlled matrix metalloproteinase-9 hyperexpression promotes behavioral recovery after ischemia 被引量:3
15
作者 Hongxia Cai Zhihao Mu +3 位作者 Zhen Jiang Yongting Wang Guo-Yuan Yang Zhijun Zhang 《Neuroscience Bulletin》 SCIE CAS CSCD 2015年第5期550-560,共11页
Matrix metalloproteinase-9(MMP-9) plays a beneficial role in the sub-acute phase after ischemic stroke.However,unrestrained MMP-9 may disrupt the blood-brain barrier(BBB),which has limited its use for the treatmen... Matrix metalloproteinase-9(MMP-9) plays a beneficial role in the sub-acute phase after ischemic stroke.However,unrestrained MMP-9 may disrupt the blood-brain barrier(BBB),which has limited its use for the treatment of brain ischemia.In the present study,we constructed lentivirus mediated hypoxiacontrolled MMP-9 expression and explored its role after stroke.Hypoxia response element(HRE)was used to confine MMP-9 expression only to the hypoxic region of mouse brain after 120-min transient middle cerebral artery occlusion.Lentiviruses were injected into the peri-infarct area on day 7 after transient ischemia.We found hyperexpression of exogenous HRE-MMP-9 under the control of hypoxia,and its expression was mainly located in neurons and astrocytes without aggravation of BBB damage compared to the CMV group.Furthermore,mice in the HRE-MMP-9 group showed the best behavioral recovery compared with the normal saline,GFP,and SB-3CT groups.Therefore,hypoxia-controlled MMP-9 hyperexpression during the sub-acute phase of ischemia may provide a novel promising approach of gene therapy for stroke. 展开更多
关键词 blood-brain barrier hypoxia response element matrix metalloproteinase 9 stroke
原文传递
Theoretical Study on Electron Transfer Matrix Element in Oxidation of α-Amino Carbon-Centered Radical by O_2
16
作者 刘继凤 朱权 +1 位作者 李象远 杨胜勇 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2002年第10期972-977,共6页
As a successive work of our previous paper, 1 the electron transfer matrix element (V rp) in the oxidation of the simplified model molecule of α-amino carbon-centered radical by O 2 has been investigated wi... As a successive work of our previous paper, 1 the electron transfer matrix element (V rp) in the oxidation of the simplified model molecule of α-amino carbon-centered radical by O 2 has been investigated with ab initio calculation at the level of UHF/6-31++G**. Based on the optimized geometries of the reactant and the ion-pair complex obtained previously, the reaction heat and the inner reorganization energy have been obtained by constructing the potential energy curves of reactant and product states considering the solvent effect with the conductor-like screening model (COSMO). The solvent reorganization energy has been estimated using Lippert-Mataga relationship. The calculated results show that the value of V rp is several times larger than that of RT, which means that the model reaction is an adiabatic one. Theoretical investigation indicates that the solvent effect on the direct electron transfer (ET) process of oxidation of α-amino carbon-centered radical by oxygen is remarkable. 展开更多
关键词 electron transfer solvent reorganization energy ET matrix element
原文传递
Stiffness Matrix Derivation of Space Beam Element at Elevated Temperature
17
作者 杨秀英 赵金城 龚景海 《Journal of Shanghai Jiaotong university(Science)》 EI 2010年第4期492-497,共6页
<Abstract>Element stiffness equation is very important in structural analysis,and directly influences the accuracy of the results.At present,derivation method of element stiffness equation is relatively mature u... <Abstract>Element stiffness equation is very important in structural analysis,and directly influences the accuracy of the results.At present,derivation method of element stiffness equation is relatively mature under ambient temperature,and the elastic phrase of material stress-strain curve is generally adopted as physical equation in derivation.However,the material stress-strain relationship is very complicated at elevated temperature,and its form is not unique,which brings great diffculty to the derivation of element stiffness equation.Referring to the derivation method of element stiffness equation at ambient temperature,by using the continuous function of stress-strain-temperature at elevated temperature,and based on the principle of virtual work,the stiffness equation of space beam element and the formulas of stiffness matrix are derived in this paper,which provide basis for finite element analysis on structures at elevated temperature. 展开更多
关键词 elevated temperature space beam element element stiffness matrix principle of virtual work
原文传递
Coupling matrix element of electron self-exchange reactions in solution
18
作者 步宇翔 刘成卜 邓从豪 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1998年第6期509-513,共5页
On the basis of the common feature among the electron transfer process and the ion hydration process as well as the relevant experimental kinetic data of electron trader reaction, a new accurate hydration potential fu... On the basis of the common feature among the electron transfer process and the ion hydration process as well as the relevant experimental kinetic data of electron trader reaction, a new accurate hydration potential function scheme for the determination of electron transfer coupling matrix element is presented. The coupling matrix element between two hydrated ions of the reacting system in solution is calculated. The results and the applicability of this scheme are discussed. 展开更多
关键词 Electron transfer reaction coupling matrix element nonadiabatic transition hydration potential function
全文增补中
First lattice QCD calculation of semileptonic decays of charmed-strange baryonsΞc
19
作者 张其安 华俊 +7 位作者 黄飞 李任博 李园园 吕才典 孙鹏 孙玮 王伟 杨一玻 《Chinese Physics C》 SCIE CAS CSCD 2022年第1期12-20,共9页
While the standard model is the most successful theory to describe all the interactions and constituents of elementary particle physics,it has been constantly scrutinized for over four decades.Weak decays of charm qua... While the standard model is the most successful theory to describe all the interactions and constituents of elementary particle physics,it has been constantly scrutinized for over four decades.Weak decays of charm quarks can be used to measure the coupling strength between quarks in different families and serve as an ideal probe for CP violation.As the lowest charm-strange baryons with three different flavors,Ξ;baryons(composed of csu or csd)have been extensively studied in experiments.In this study,we use state-of-the-art lattice QCD techniques to generate 2+1 clover fermion ensembles with two lattice spacings,a=(0.108,0.080 fm).Then,we present the first ab-initio lattice QCD calculation of the Ξ;→Ξ form factors.Our theoretical results for the Ξc→Ξl;v;decay widths are consistent with and approximately two times more precise than the latest measurements by the ALICE and Belle collaborations.Based on the latest experimental measurements,we independently obtain the quark-mixing matrix element |V;|,which is in good agreement with results from other theoretical approaches. 展开更多
关键词 Ξc semileptonic decays lattice QCD form factors CKM matrix elements
原文传递
Physics program of open charm and heavy c states at the BES-Ⅲ experiment
20
作者 荣刚 《Chinese Physics C》 SCIE CAS CSCD 2010年第6期788-794,共7页
We present the physics program of the open charm and heavy cc states above the DD production energy threshold, which will be studied with the BES-Ⅲ detector at the BEPC- Ⅱ collider in the coming years. Based on some... We present the physics program of the open charm and heavy cc states above the DD production energy threshold, which will be studied with the BES-Ⅲ detector at the BEPC- Ⅱ collider in the coming years. Based on some full Monte Carlo simulations with the BES-Ⅲ detector, we predict the accuracy levels on measuring some physical quantities related to D^0, D^+ and Ds^+ decays as well as some non-charmed decays of the heavy cc states. 展开更多
关键词 D semileptonic decays D(s)^+ purely leptonic decays CKM matrix elements Standard Model D^0D^0 mixing CP violation in D decays Rare D and Ds^+ decays non-charmed decays of heavy resonances
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部