双波理论描述三维谐振子在外电气中的轨迹

用双波函数量子理论描述了在均匀外电场中带电谐振子运动的轨迹,它与经典力学结果类似,这是单波函数量子理论不能实现的。     

含时外电场中带电谐振子的双波描述

讨论含时外电场中带电谐振子的双波描述，给出相关物理量的时间演化方程，得到双波描述的经典极限与纯经典描述相一致的结论。     

各向异性n维耦合谐振子能量本征值的代数解法

耦合谐振子是量子光学中的重要研究问题之一,原因是许多实际物理问题的解决都依赖于耦合谐振子的模型,因此研究耦合谐振子求解的简便方法显得十分必要。本文运用数学上二次型正交化理论构造了一个形式上的变换矩阵,使既有坐标耦合又有动量耦合的各向异性n维耦合谐振子的Hamilton量对角化,求出了其本征值。并应用此方法求解了三维耦合谐振子的本征值,验证了该方法的正确性。由于该方法不需要求出变换矩阵的具体形式,使得运用此方法求解具有对称形式的Hamilton量的本征值问题变得简单、易计算出结果,该方法更具有普遍性,是一种十分有效的代数方法。     

半球谐振陀螺仪线振动影响分析

在实际运用中,半球谐振陀螺仪受各种环境因素包括线振动的影响,而线振动可能会改变半球谐振子的工作状态。分析半球谐振陀螺仪在谐振子质量沿圆周角分布不均匀的情况下,线振动引起的惯性力对半球谐振子的工作状态的影响,并通过考察半球谐振子驻波进动角的变化来判断谐振子工作状态是否发生变化。结果表明,只有在线振动频率等于陀螺固有频率时,线振动才会对半球谐振陀螺仪谐振子的工作状态产生显著影响。     

超对称谐振子的双模相位算符及其本征态

在超对称谐振子的双模相位空间里构造了二类独立的相位算符并相应地求出了基本征态。     

基于分次吹制工艺的微半球陀螺制作

提出了一种微半球谐振子分次吹制工艺新方法,通过增加第二次旋转吹制的方式,以补偿第一次吹制过程中由于温度场不均匀性造成的谐振子对称度误差。设计了微半球陀螺整体工艺方案,并制作了硼硅酸玻璃材质的微半球谐振子及陀螺样品,测试结果表明,分次吹制后的谐振子频差由单次吹制的30～60 Hz降至10 Hz以内。经与力平衡控制电路联调,陀螺零偏不稳定性为8.2 (°)/h。     

开环位置激励半球谐振陀螺仪工作原理与误差分析

为了研究半球谐振陀螺仪的工作原理,首先推导了谐振子上振动波腹方位角的表达式,然后建立了振动位移和速度的状态方程,进而求出了状态方程的精确解析解,给出了在角速率输入和存在密度分布不均匀缺陷时的波腹方位角的稳态解和角速率解算误差.最后在开环位置激励下,给出了为保证半球谐振陀螺角速率估计精度的密度四次谐波的取值范围.     

反射镜拼接相机渐晕消除方法

分析了反射镜拼接相机渐晕现象产生的原因,得出渐晕能量分布数学模型.利用MATLAB对数学模型进行仿真,得出能量分布曲线;利用渐晕数学模型求出渐晕区域后,采用函数逼近法拟合出渐晕区域内各点的补偿因子曲线,得出补偿因子和亮度值的关系;通过对辐射定标图像和外场成像图像处理后,很好地消除了渐晕现象.     

相对论电子在周期磁场中的辐射频谱

分析了相对论电子在空间周期磁场中的运动轨迹.在一定条件下,电子在垂直原始入射方向上的运动是简谐的,利用谐振子模型求出了它的辐射频谱和频宽;最后讨论了运动的非谐性.得到辐射频谱分布将是与电子的初速度、磁场强度有关.     

不均匀电介质中的并矢格林函数问题

本文讨论了不均匀电介质系统中的电磁场的边值问题。把相对介电常数ε_r(R)作为权函数,证明了不均匀介质系统中本征函数系的正交性和完备性;因而可以应用本征函数展开法求出并矢格林函数的普遍形式。由于不均匀介质中的电磁场有和均匀介质中的类似的性质,所以我们最终也可以通过对标量格林函数的直接求解方法来解决介质加载系统的并矢格林函数问题。     

A K-band oscillator locked to the first water resonance

A Gunn diode oscillator has been locked to the rotational absorption line of water at 22235.170 MHz. The water in vapor form was obtained from atmospheric air. The air was held in a vacuum chamber which was inserted in a Fabry-Perot open semiconfocal resonator. A sinusoidal electric field, the Stark field, was impressed upon the gas in the cavity which is coupled to the Gunn oscillator, thus modulating the water vapor absorption of microwave energy. The second harmonic of the Stark Field was used to lock the Gunn oscillator. Working with the water spectral line (16₁₆-5₂₃) at 22.235 GHz, a frequency stability on the order of ±50 kHz was achieved     

基于混沌振子系统的电力谐波检测研究

利用混沌振子检测电力谐波的方法,改进了振子相变的自动判别方法。设计了一个电力谐波检测系统,仿真结果表明其在高次谐波检测上的优越性,为电力系统谐波时域检测的设计提供了依据。     

Electron transport in semiconductors under a strong high frequency electric field

We propose an analytical approach to study the electron transport in semiconductors when a strong high frequency (HF) electric field is applied together with a weak direct current (DC) electric field. We derive a set of dynamic equations, from which the amplitude and phase of each harmonic component of the electron drift velocity and the electron temperature can be obtained. Our calculation shows that the DC conductivity in an n-GaAs sample decreases dramatically with increase of the first and second harmonic applied electric fields and definitely becomes negative.     

Electromagnetic missile launched from a uniform current sheet ofarbitrary shape

A time-domain method, referred to as the variable transformation method, is used to study the transient radiation field from a uniform current sheet of any shape. A uniform current sheet of arbitrary shape is found to be capable of launching an electromagnetic missile (EMM) over the area equal to that of the sheet. The authors first derive the time-domain expression of the transverse electric and magnetic field strength along the axis of a circular sheet. The EMM condition is then derived in the time-domain form. It is then proven that the EMM can exist over an area equal to that of the sheet in any shape     

Proposal of a Microwave-Driven Semiconductor Superlattice Oscillator for Generation of THz Radiation

We present the proposal of a microwave-driven semiconductor superlattice oscillator. We show that the interplay of a microwave pump field with a synchronous harmonic field can make a semiconductor superlattice to a gain medium for the harmonic field. Placing the superlattice in a resonator for the harmonic field allows the operation of an oscillator. The gain mechanism is based on Bloch oscillations of miniband electrons. The gain is mediated either by the interaction of the high-frequency field with the single electrons or with space charge domains or with both. The microwave-driven superlattice oscillator should be suitable for generation of coherent radiation up to several THz.     

静电场对强激光场中氢原子产生高次谐波的影响

利用分裂算符方法数值求解了真实氢原子在强激光场和静电场作用下的含时薛定谔方程,研究了静电场对强激光场中氢原子产生高次谐波的影响.研究表明,静电场加入后,奇次谐波的强度有所降低,并且谐波谱中出现偶次谐波和双平台结构.利用小波变换,观察了高次谐波在不同时刻的发射情况.借助于半经典理论,解释了在静电场作用下高次谐波发生变化的机制.     

Double-resonance Semiconductor Superlattice Parametric Oscillator for Generation of Subterahertz Radiation

We report on a subterahertz superlattice parametric oscillator that operated simultaneously at two different harmonic frequencies of a microwave pump field. A pump field (frequency near 100 GHz) was coupled to a GaAs/AlAs superlattice in a resonator for the third and the fifth harmonic. The pump field produced a third harmonic field and this together with the pump field created a fifth harmonic field. A theoretical analysis indicates that the nonlinearity, which is based on the dynamics of miniband electrons, should allow for the upconversion of pump radiation of higher frequency into the terahertz frequency range.