电磁场角动量守恒定律的简明推导

对电磁场角动量守恒定律作了一种简明的推导。     

The Electromagnetic Sector of the Evans Field Theory

The equations of the electromagnetic sector of the Evans field theory are given in terms of differential geometry and are based on the well-known structure relations and Bianchi identities. The equations thus complete Einstein’s basic axiom, that physics is derived from geometry, and extend the axiom to electrodynamics. Precise tests are suggested for the theory using the interaction of circularly polarized electromagnetic radiation with a non-relativistic electron beam. These tests include; the inverse Faraday effect (IFE), radiatively induced fermion resonance (RFR), and the electromagnetic Aharonov-Bohm (EMAB) effect.     

The Electromagnetic Sector of the Evans Field Theory

No Heading The equations of the electromagnetic sector of the Evans field theory are given in terms of differential geometry and are based on the well-known structure relations and Bianchi identities. The equations thus complete Einsteins basic axiom, that physics is derived from geometry, and extend the axiom to electrodynamics. Precise tests are suggested for the theory using the interaction of circularly polarized electromagnetic radiation with a non-relativistic electron beam. These tests include; the inverse Faraday effect (IFE), radiatively induced fermion resonance (RFR), and the electromagnetic Aharonov-Bohm (EMAB) effect.     

角动量演示仪器的设计

设计了角动量演示装置 ,该装置结构简单 ,便于携带 ,可较好的演示角动量守恒和决定转动惯量的因素等 .     

验证变力作用下的动量定理

利用CBL技术在变力作用下验证了动量定理,并介绍了实验原理及实验步骤.     

旋转带电体和电磁场的角动量守恒定律及能量守恒定律

对均匀带电薄球壳匀加带旋转问题,由电磁场的角动量定恒守律和能量守恒定律两种方法分别得出了外力矩力其功率的正确正确结果。     

Equivalence of the Abraham momentum and the Minkowski momentum of photons in media

The century-long debate on the momentum of light in a medium involves two rival forms of momentum, namely those of Abraham and Minkowksi. In this Letter, we analyze this dilemma from the view of the quantum theory of light, the result of which can be easily extended to the classical level. It is found that the Abraham momentum of one polariton mode in linear and dispersive dielectrics differs from its Minkowski momentum, by a considerable factor. However, after taking all branches into consideration, we find the two lead to the same end, which unifies the two rival forms of momentum. The sum rule is traditional, but our conclusion provides a new perspective on the Abraham-Minkowski dilemma, and is consistent with existing experiments including a recent measurement of recoil momentum of atoms using an atom interferometer with Bose-Einstein Condensates [G. K. Campbell et al. Phys. Rev. Lett. 94, 170403 (2005).], the Cerenkov effect, the Doppler effect and the phase matching conditions in nonlinear optical processes.     

近代物理实验教学改革与实践

绍了中国科学技术大学理学院近代物理系的专业实验的改革思路、改革内容及教学实验和课程教材的建设情况．     

Further Support of the Reliability of the Limit on Photon Mass Given by the Rotating Torsion Balance Experiment

We consider there is a vacancy in the plasma in the solar system,and calculate the vector potential produced by the magnetic field frozen in the plasma.The result shows that,in the vacancy,the vector potential produced by the magnetic field frozen in the plasma is much less than the large scale cosmic vector potential.This means if our earth is in such a vacancy,the total vector potential on the surface of the earth is dominated by the cosmic magnetic vector potential,which gives a further support of the reliability of the limit on photon mass given by rotating torsion balance experiment [Phys.Rev.Lett.90(2003) 081801].     

用于近代物理实验教学的振动样品磁强计

简述了振动样品磁强计的工作原理,采用电磁驱动方式自制了振动样品磁强计.利用该仪器测试了各向同性永磁钡铁氧体的永磁特性,与商业振动样品磁强计的测量结果相比,测量误差小于1%,可用于近代物理实验教学.     

Odd-even effect in fragment angular momentum in low-energy fission of actinides

Quantitative explanation for the odd-even effect on fragment angular momenta in the low-energy fission of actinides have been provided by taking into account the single particle spin of the odd proton at the fragment’s scission point deformation in the case of odd-Z fragments along with the contribution from the population of angular momentum bearing collective vibrations of the fissioning nucleus at scission point. The calculated fragment angular momenta have been found to be in very good agreement with the experimental data for fragments in the mass number region of 130–140. The odd-even effect observed in the fragment angular momenta in the low-energy fission of actinides has been explained quantitatively for the first time.      

Electron momentum distributions and compton profiles of some molecules with FSGO model

The electron momentum distributions and the Compton profiles (within the impulse approximation) of H₂, LiH, methane, water, acetylene, ethylene, ethane cyclopropane and cyclobutane have been calculated using the floating spherical Gaussian orbital (FSGO) wavefunctions. The agreement of the single-FSGO Compton profiles with the corresponding experimental or the Hartree-Fock (HF-SCF) theoretical ones is fairly good in most of the cases examined. The advantages and drawbacks of using the FSGO model for the calculation of Compton profiles are discussed.     

Magnetic Manipulation of Massless Dirac Fermions in Graphene Quantum Dot

We have theoretically analyzed the quasibound states in a Mraphene quantum dot （GO, D） with a magnetic flux -φ in the centre. It is shown that the two-fold time reversal degeneracy is broken and the quasibound states of GQD with positive~negative angular momentum shifted upwards/downwards with increasing the magnetic flux. The variation of the quasibound energy depends linearly on the magnetic flux, which is quite different from the parabolic relationship for SchrSdinger electrons. The GQD＇s quasibound states spectrum shows an obvious Aharonov-Bohm （AB） oscillations with the magnetic flux. It is also shown that the quasibound state with energy equal to the barrier height becomes a bound state completely confined in GQD.     

Electromagnetic mass differences oft-flavored hadrons in modified bag model

Mass difference oft-flavored hadrons is calculated using bag model modified for considering heavy quarks inside the bag. Both electric and magnetic contributions to mass differences are evaluated without the assumption of degenerate intermediate state. Mass differences between up and down quarks inside the bag is taken to be a constant in the absence of a dynamical calculations for the same.     

"电场生物学效应"引入大学物理实验教学的探讨

为培养学生创新意识和能力,实现物理实验教学现代化,本文介绍了将“电场生物学效应”科研工作中取得的部分成果引入大学物理实验教学的一些尝试。     

悬线式二维碰撞实验

提出用长摆线单摆实现在准水平面内的无摩擦运动,用摄像头记录二维碰撞过程,设计了检验二维碰撞中动量守恒和机械能守恒的教学实验.     

Remark on the Connectedness of Space in the Experimental Devices of Aharonov-Bohm Effect

This article shows that in Aharonov-Bohm (AB) effect arrangements, the electron wave propagation spaceis doubly connected for two real coherent sources, and simply connected under certain condition for two virtual coherentsources, and all known AB experiments belong to the latter case. By the Feynman path integral method, we show thatin the former case there is no AB effect, whereas in the latter case there is.     

The Three-Dimensional Dirac Oscillator in the Presence of Aharonov-Bohm and Magnetic Monopole Potentials

No Heading We study the Dirac equation in 3+1 dimensions with non-minimal coupling to an isotropic radial three-vector potential and in the presence of a static electromagnetic potential. The space component of the electromagnetic potential has angular (non-central) dependence such that the Dirac equation separates completely in spherical coordinates. We obtain solutions for the case where the three-vector potential is linear in the radial coordinate (Dirac oscillator) and the time component of the electro-magnetic potential vanishes. The relativistic energy spectrum and spinor eigenfunctions are obtained.     

博雅理念在大学物理实验教学中的实践

博雅教育是对大学本科生实施的一种教育,它更关注个人的发展而不是为具体职业做准备,作为理科和工科大学所共有的基础课程——大学物理实验,是最能体现博雅教育理念的课程之一.但是教师如果缺乏理念和意识,博雅的哲学教育以及教育的目标就无法得到很好的贯彻.本文以具体的大学物理实验教学为例,从微观层面进行分析和阐述,研究如何结合博雅教育思想来实践教学.