双波场共振泵浦的四能级原子系统

本文运用Dressed原子态方法;把四能级原子与两个激光场和一个探测场的相互作用转化为四能级原子与一个弱探测吸收场的相互作用,然后采用微扰理论求解Dressed原子表象中的密度矩阵方程,得出吸收谱的解析表达式,并详细讨论了吸收谱的各种持性.最后,导出了由外场感应的能级间的电偶极矩表达式,并找出了吸收谱与它的关系.     

电磁测井的物理基础

本文介绍电磁场理论在石油测井中的应用,主要介绍感应测井和相位介电测井的基本原理．感应测井涉及变化频率较低的似稳电磁场问题,可由测量感应电动势的振幅来区分油气层与非油气层．相位介电测井涉及高频变化的电磁场问题,可由测量电动势的位相差来解决区别油气层与水淹层的问题．两种测井方法所测的电动势都是由变化电磁场的非辐射场部分产生的,因此它们是这部分非辐射场在工业技术上应用的重要例子．     

RESEARCH ANNOUNCEMENTS——Modular [Distributive] Left Regular Bands

ＲＥＳＥＡＲＣＨＡＮＮＯＵＮＣＥＭＥＮＴＳＭｏｄｕｌａｒ［Ｄｉｓｔｒｉｂｕｔｉｖｅ］ＬｅｆｔＲｅｇｕｌａｒＢａｎｄｓＬｕｏＹａｎｆｅｎｇ（罗彦锋）ＧｕｏＸｉａｏｊｉａｎｇ（郭小江）ＭＲ（１９９１）ＳｕｂｊｅｃｔＣｌａｓｉｆｉｃａｔｉｏｎ：２０Ｍ１０...     

同时采用P矩阵法和多波长直线回归法测定脑清片中两组分的含量

本文经选择适当的测定波长，同时采用Ｐ－矩阵法和多波长直线回归法测定脑清片中氨基比林和咖啡因的含量。两个方法简便、快速、准确。样品测定结果均和北京市药品标准法测定结果一致。     

GEOMETRIC PHASES AND SCHR?DINGER''S CAT STATE

A matrix method is presented for treating the dynamical phases, adiabatic phases and nonadiabatic phases of quantum superposition states. It is effective for any parameter-varying Hamiltonian system. As two examples, the evolution of mass-varying harmonic oscillator and the evolution of coherent states under parameter-varying displaced operator have been studied, Some new phenomena are obtained in the first case and the possible producing of so-called Schr?dinger's cat state by geometric phases is pointed out. The quantum state useful for the quantum optical verification of Berry's phase is introduced.     

REALIZATION OF THE WAVE-PACKET-COLLAPSE —A VIEWPOINT TO THE QUANTUM MEASUREMENT THEORY

An interpretion of the wave-packet-collapse (WPC) in the system of quantum mechanics is given. We find a connection between the WPC and the limitation to the measurement precision determined by the quantum fluctuation. A simple and explicit relation about them is obtained.     

稀土氧化物薄膜的制备及其光学性能

本文介绍了Gd_2O_3、Eu_2O_3、Yb_2O_3薄膜制备方法的研究结果,所述的光学性能指的是用电子枪蒸发的0.2—9μm波长范围内薄膜的光学常数n和k,并对红外吸收带作了说明。     

铝基薄膜忆阻器作为感觉神经系统的习惯化特性

感觉神经系统可在外界刺激与生物体反应之间建立联系.感觉神经系统中的最小单位神经元可直接将外界刺激传递至中枢神经,再由中枢神经通过控制和调节生物体对外界刺激作出反应.神经突触连接了相邻神经元进行脉冲信息传递功能.习惯化是神经突触在信息传递中过滤外界无关信息时的一个基本特性,可以让感觉神经系统更快速地适应外界环境变化.忆阻器模拟神经突触功能在近年获得进展,然而针对以忆阻器为基础的具有习惯化特性的神经突触以及完整神经系统的研究相对匮乏.本文利用磁控溅射技术制备了厚度约为40 nm且含铝纳米颗粒的氮化铝薄膜忆阻器,并发现这种结构忆阻器对于重复的外界刺激有明显的习惯化行为,该行为与感觉神经系统的习惯化特性极为相似.若将这种具有习惯化的神经突触与感觉神经元串联,可形成LIF(leaky integrate-and-fire)生物模型模拟完整的神经系统行为,也为忆阻器在第三代神经网络(脉冲神经网络)中的应用提供理论参考.     

Electromagnetic scattering from two-layer rough interfaces in the Kirchhoff approximation

Electromagnetic wave scattering from multilayers consisting of two two-layer Gaussian rough surfaces with lossless media is investigated in the Kirchhoff approximation (KA), with consideration of the shadowing effects. The tapered incident wave is introduced into the classic KA, and the bistatic scattering coefficient is redetermined. The advantage of this method is that it is faster in computation than the exact numerical methods. The numerical results show that the bistatic scattering coefficient calculated in the KA is in good agreement with that obtained by using the method of moment (MOM) over a most angular range, which indicates the validity of the KA proposed in our paper. Finally, the effects of the relative permittivity, the root-mean-square (RMS) height, the correlative length, and the average height between the two interfaces on the bistatic scattering coefficient are discussed in detail.     

56MeV—70MeV~(12)C+~(28)Si弹性散射研究

用大面积位置灵敏电离室测量了69.5MeV,66MeV,59MeV和56MeV轰击能量下~(12)C+~(28)Si弹性散射角分布。用光学模型对实验数据进行了拟合,并讨论了弹散角分布振荡及增强的可能原因。