激光技术在薄膜科学中的应用

膜的一维尺寸大大小于其余两维。一般把厚度小于1μm的膜称为薄膜,反之则称为厚膜。由于薄膜材料具有许多优异性能,因此近年来薄膜科学的发展极为迅速,涌现出许多薄膜制备技术与方法,如真空蒸发沉积、磁控溅射沉积、离子束溅射沉积、金属有机物化学气相沉积和分子束外延等等。虽然这些各具特色的方法在薄膜研究中得到了广泛应用,但是都各具局限性,不能满足薄膜研究和制备的需要,而激光则具有单色性和方向性好、功率密度高等一系列优点。激光沉积薄膜的方法主要分为两类:一类是激光化学反应沉积,如激光化学气相沉积(laser chemical vapor dep…     

《强激光与粒子束》2006年度的总被引频次和影响因子

从2007年10月万方数据公布的2007年版《中国科技期刊引证报告（核心版）》上获悉：《强激光与粒子束》2006年度的总被引频次为1158，在全部1723种期刊中列246位；影响因子为0．560，名列417位。在物理学类31种期刊中，总被引频次排名第7，影响因子排名第14。《中国科技期刊引证报告》已经连续出版11年，收录的中国科技论文统计源期刊即中国科技核心期刊，是经过严格的定量和定性分析选取出来的各学科的重要科技期刊，每年都在动态变化，2006年度共1723种。近年来，随着《强激光与粒子束》的不断发展，刊物的质量不断提高，影响力逐步增大，总被引频次和影响因子有了较大幅度的提升。     

超声波电机的原理与应用

 超声波电机(Ultrasonic Motor，USM )是国外近20年发展起来的一种新型电机。事实上，在超声波电机问世之前，已有以压电效应进行驱动的电机，但其频率并不局限于超声波范围内。早在1984年，威廉和布朗就申请了“压电马达”的美国的专利；1964年，前苏联基辅理工学院设计了第一个压电旋转电机；1970～1972年西门子和松下发明了压电步进电机，不过因为无法达到较大的输出转矩而没能实际应用。1980年日本指田年生研制成超声波压电电动机（即现代意义上的超声波电动机），克服了传统压电电动机转换效率低和变位微小的缺陷，使压电电动机进入工业实用阶段。     

基于MATLAB的线性调频Z变换及应用

作为数字信号处理的一种算法,线性调频Z变换(Chirp-Z)是适用于更为一般情况下沿螺旋曲线计算有限时宽Z变换的快速变换算法,它使得DFT的运算变得相当灵活,为数字信号处理技术应用于各种高速信号的快速处理创造了良好的条件,从而大大推动了数字信号处理技术的发展.     

物理概念和公式的教学探究

物理教学的主要任务是学习基础知识,掌握基本技能,为专业课打基础．在教学活动中,把握好概念和公式是关键．笔者在教学实践中,应用三步教学法,取得的教学效果比较显著．第一步从具体到抽象概念和公式是科学的概括,是客观规律,比较抽象,学生不易理     

多晶硅薄膜太阳能电池的研究进展

1前言太阳能的光伏应用已给我们展示了非常广阔的前景．因此,可将太阳能转化为电能的太阳能电池的研制和发展正日益引起关注．硅太阳能电池是最有发展前景的．目前,晶体硅太阳电池因丰富的原材料资源和成熟的     

开边界条件下一类新Hubbard模型的精确解

用坐标Bethe ansatz方法详细研究了开边界条件下一类新Hubbard模型的可积性问题. 得到了系统的能谱、可积边界条件和Bethe ansatz方程.     

Evaluation of Optical Properties of Self-Frequency-Doubling Crystal Yb：GdYAl3（BO3）4 for Laser Applications

Yb：GdYAl3 （B03）4 （Yb：GdYAB） is investigated as a new laser crystal for potential applications in self-frequency doubling. The emission and absorption properties of Yb：GdYAB crystal are studied, and the emission decay times of the upper laser level are measured. The emission cross sections are evaluated using the absorption cross section and principle of reciprocity. The other laser performance parameters, such as the minimum inversion fraction βmin, pump saturation intensity Isat and minimum pump intensity 1rain, are also calculated. The results are discussed in the framework of requirements for an effective diode-pumped Yb^3＋ laser system. Yb：GdYAB is expected to exhibit the most useful laser properties and to be superior to Yb：YAB crystal that has been excellent self-frequency-doubling crystal at present in many key spectroscopic parameter values.     

Propagation Properties of Gaussian-Shaped and Double-Side Unsymmetrical Metallic Nano-Corrugations

A Gaussian-shaped and double-side unsymmetrical groove structure is presented. Rigorous calculation of the optical properties of the structure is performed on the basis of a multiple multipole program. We analyse the effect of the grating period, the groove width and the film thickness on transmission and reflectance. Simulation results demonstrate that surface-plasmon-polariton resonance positions depend strongly on the structure period and can be changed slightly by the variation of incomplete perforation thickness, while the resonance peak values can be controlled by tuning the groove width. Our results not only give an insight into the physical mechanisms of the double-side unsymmetrical gratings, but also open a way to design novel nano-photonic devices.     

The relationship between acoustic radiation modes and structural modes and its applications

Both acoustic radiation modes and structural modes play an important role in the field of structure-borne sound, however, little work has been done for inherent relations between these two kinds of modes. This paper is focused on the relationship between the radiation modes and structural modes and its physical mechanisms. First, a governing equation for relating the radiation mode and structural mode is given based on the characteristics of the modes. Then, using the symmetric or anti-symmetric properties of two kinds of modes, the corresponding relations are presented. And then, numerical examples are given to verify the theoretical investigations, and it has been shown that, for a simply supported rectangular panel vibrating at low frequencies, the first radiation mode is dominant corresponding to (odd, odd) structural modes; the following radiation modes are respectively dominant corresponding to (even, odd), (odd, even), and (even, even) structural modes. Finally, such relations are applied to active acoustic structural control and provide a direct help for the design of active control strategy and arrangement of the secondary forces.