长余辉材料Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+)中稀土离子的发光特性

利用同步辐射光源(德国HASYLAB实验室的SUPERLUMI实验站)和真空紫外激光(157.6nm)对新型蓝光发射长余辉材料Sr2MgSi2O7∶Eu2 (0·2%),Dy3 (8%)进行了光谱研究。在170nm同步辐射光源激发下,观察到对应Eu2 :5d-4f跃迁的477nm发射带和对应Dy3 :4f-4f跃迁的两组线谱发射,其中只有来自Eu2 的5d-4f发射对长余辉光谱有贡献。在157.6nm激光激发下,除了上述发射外,还明显观察到对应Eu3 的红色线谱(590,614,626nm)。结合这些光谱特性,对Sr2MgSi2O7∶Eu2 ,Dy3 中稀土离子的发光特性以及长余辉发光机理进行了讨论,并提出了Eu2 充当空穴陷阱的可能性。     

在重力场和磁场影响下自旋刚性航天器的周期运动

考虑重力场和磁场对轴对称航天器本体的影响，研究其质心在圆形轨道上的运动,通过降低系统的运动方程数，并将它变成为一个带电粒子在电磁场作用下的平面运动．确认系统运动是稳定的，并通过Liapunov全纯积分定理，构建其近似的周期运动.     

Do the Experimental Violations of Bell Inequalities Require a Non-Local Interpretation of Quantum Mechanics？

Since the data show that Bell inequalities are violated experimentally, we must conclude that any hidden variable theory （which correctly predicts experimental data ） will be non-local. But, to conclude that the experimental violations of Bell inequalities show quantum mechanics to be non-local is unjustified. Specifically, the key assumptions required to obtain a Bell inequality are （ 1 ） locality and （2） the assignment of meaningful （ non- negative） probabilities to seemingly physical correlations （Bell expresses these correlations via ＂ hidden variables＂ ）. Since the Bell inequality is violated by experiment, at least one of these assumptions is wrong. The widespread conclusion that locality must be relinquished is valid only if we retain the previously mentioned correlations （ ＂hidden variables＂ ）. We will demonstrate that the latter are not physical observables - they are not elements of physical reality.     

Linear Volterra Integral Equations

The Kurzweil-Henstock integral formalism is applied to establish the existence of solutions to the linear integral equations of Volterra-typewhere the functions are Banach-space valued. Special theorems on existence of solutions concerning the Lebesgu3 integral setting are obtained. These sharpen earlier results.     

超模的同构定理

本文利用模论导出超模的三个同构定理,同时,给出超模的Jordan-Holder定理,最后,探讨了超模的基本关系∈~*,并研究其性质．     

Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation

The application of radiation technology in the en-vironmental protection was listed as one of the mostimportant research fields by the International AtomicEnergy Agency (IAEA) for the peaceful use of nuclearenergy. It has great research value and potential appli-cation. Because of their broad-spectrum antimicrobialproperties, Cholophenols (CPs) have been used aspreservative agents for wood, paints, vegetable fibersand leather and as disinfectants. In addition, they havebeen widely employed…     

利用低能质子束产生高强度放射性束流

加拿大TRIUMF实验室利用¹¹C成功验证了一种产生高强度(～10⁸ions/s)放射性束流的方法. 该方法不同于普通在线同位素分离方法, 它利用了13MeV的低能强流质子束, 可以产生一系列核天体物理实验感兴趣的高强度放射性束流.     

Non-Achievability of Metal-Insulator Transition in Two-Dimensional Systems

We present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the 2D case. The many body effects are included in the screening function, and binding energies of a donor are obtained as a function of impurity concentration so as to find out the possible way leading metal-insulator transition in the 2D system. While solving for the binding energy for a shallow donor in an isolated well of a GaAs/Ga1-x Als As superlattice system within the effective mass approximation, it leads to unphysical results for higher concentrations. It shows that the phase transition, the bound electron entering into the conduction band whereby （H）min=0, is not possible beyond this concentration. The results suggest thai a phase transition is impossible in 213 systems, supporting the scaling theory of localization. The results are compared with the existing data available and discussed in the light of existing literature.     

斜向静磁场中光导波模式转换与衍射理论

应用经典场论和耦合模理论计算了斜向静磁场作用下，磁性薄膜波导中静磁波与导波光的相互作用.计算结果表明，与垂直静磁场情形相比，斜向静磁场时的相匹配条件有所变化，由于磁性薄膜波导中法拉第磁光效应增强等因素，导波光的Bragg衍射效率得以显著增加.这有利于应用YIG等低损耗磁性薄膜做成高衍射效率的磁光波导器件，亦有利于降低Bi∶YIG等高比法拉第旋转的磁光薄膜波导器件的体积和损耗.此外，理论指出的在斜向静磁场条件下所具有的一些磁光特性与实验结果亦符合得很好. 关键词：     

Theoretical analysis on waveform structures of pulse propagating in shallow water with an ideal thermocline

I.IntroductionDuetospatia1andtemporalvariabilityoftheocean-acousticenvironment,especially,theeffectsofboundaryaswel1asmediumonpropagationofacousticwavesinshal1owwater,theacousticpropagationisextrcmelycomp1icatcd.Multipathtransmissionisthebasiccharacteris-hcsofunderwatersoundchannels.Undctcrminedmultipathstructurescangreatlylimittheperformanceofunderwateracousticdetcction.However,ifthemultipathcharacteristicsofacousticpropagationinunderwatcrsoundchanne1sareknown,spaee-timeresolutionandpro-cess…