相移阴影莫尔基于迭代LSM拟合

相移阴影莫尔技术相位高度存在着非线性关系,无法在全场获得均匀相移,因而致使经典的相移算法不能得到精确解.对此,提出了一种基于最小方差迭代的相移阴影莫尔技术,该技术通过垂直光栅面等间距移动光栅来产生相移,但光栅移动距离可不采用固定值,所以相移过程灵活|使用在高度解调过程中确定的逐点相移增量来抽取精确的测量相位,实现了相移阴影莫尔技术中固有的相位高度非线性误差补偿.结果表明,该方法可通过干涉图计算光栅的移动量,具有相移器的自标定特性.     

大学物理互动教学研究

通过分析大学物理互动教学的必要性及意义,结合自身的教学实践及兄弟单位的有关经验,探讨了大学物理互动教学的几种模式,认为：大学物理互动教学有利于体现教学以学生为主体的思想,有利于提高学生学习大学物理的积极性及主动性,大学物理互动教学法是一种值得推广的教学方法。     

Neutrino Production via e~-e~+ Collision at Z-Boson Peak

The production of the three normal neutrinos via e-e+ collision at Z-boson peak(neutrino production in a Z-factory) is investigated thoroughly. The differences of νe-pair production from νμ-pair and ντ-pair production are presented in various aspects. Namely the total cross sections, relevant differential cross sections and the forwardbackward asymmetry etc. for these neutrinos are presented in terms of figures as well as numerical tables. The restriction on the room for the mixing of the three species of light neutrinos with possible externals(heavy neutral leptons and/or sterile neutrinos) from refined measurements of the invisible width of Z-boson is discussed.     

Dark blue erenkov second harmonic generation in the two-layer-stacked hexagonal periodically poled MgO:LiNbO_3s

We report the dark blue nonlinearˇCerenkov radiation by the second harmonic generation(SHG)in a two-layer-stacked hexagonal periodically-poled-MgO:LiNbO3s(PPMgOLNs).Based on the direct wafer bonding of two target PPMgOLNs rotating around the axis perpendicular to the plane with an angle of 30°,twelve bright spots as twice of those in a single PPMgOLN are shown at each second-harmonicˇCerenkov ring.The experimental results agree with the theoretical ones and present a promising application in the fabrication of three-dimensional(3D)PPMgOLNs.     

Study on lattice vibrational properties and Raman spectra of Bi_2Te_3 based on density-functional perturbation theory

We present a variational density-functional perturbation theory(DFPT) to investigate the lattice dynamics and vibrational properties of single crystal bismuth telluride material. The phonon dispersion curves and phonon density of states(DOS) of the material were obtained. The phonon dispersions are divided into two fields by a phonon gap. In the lower field,atomic vibrations of both Bi and Te contribute to the DOS. In the higher field, most contributions come from Te atoms. The calculated Born effective charges and dielectric constants reveal a great anisotropy in the crystal. The largest Born effective charge generates a significant dynamic charge transferring along the c axis. By DFPT calculation, the greatest LO–TO splitting takes place in the infrared phonon modes and reaches 1.7 THz in the Brillouin zone center. The Raman spectra and peaks corresponding to respective atomic vibration modes were found to be in good agreement with the experimental data.     

基于“圆周运动”模型建构的高中物理深度学习

将传统学习环节依据布鲁姆教育目标分类学划分层级,以“圆周运动”模型建构为载体,研究如何从传授知识为主的传统课程过渡到以知识育人的课程改革,培养学生的建模能力.以模型建构教学为例开展深度学习教学设计,实现从浅层学习到深度学习的跨越.     

Diode-Pumped Self-Q-Switched Cr,Nd：YAG Laser with High Average Output Power

A diode end-pumped self-Q-switched Cr,Nd:YAG laser was established with pulse duration in the range of 8-10ns. The maximum average output power was 4.4 W and the slope efficiency was 27% using an output coupler of R=70%. At pumping power of 17.4 W the laser produces high-quality pulses at 1064 nm in a TEMoo-mode.     

Antiphase State in Passively Q-Switched Yb：YAG Microchip Lasers with a Nd,Cr：YAG as Saturable Absorber

We experimentally investigate the antiphase dynamics phenomenon that occurs in a diode-pumped passively Q-switched Yb:YAG multimode laser with a Nd,Cr:YAG saturable absorber. Due to the effect of spatial hole burning, the multimode lasers with one, two, or three modes at different pump power are observed, and the pulses sequences display classic antiphase dynamics.     

数学竞赛之窗

2005年国家集训队于3月14日至4月2日在辽宁沈阳东北育才学校进行了培训、测验和选拔.经过6次测验和选拔考试,选出了今年的6名国家队队员:任庆春(天津耀华中学),刁晗生(上海华师大二附中),罗晔(江西师大附中),康嘉引(广东深圳中学),邵火亘程(上海复旦大学附中),赵彤远(河北石家庄二中).选择考试命题组成员为:熊斌,王建伟,陈永高,余红兵,冷岗松,李伟固,朱华伟,郑仲义.