双孤子压缩态的特性

在线性近似条件下,量子化了非线性薛定谔方程,用后向传播法数值求解了双孤子压缩态的特性.数值结果表明,在碰撞距离附近,压缩比显著增加.减小孤子间相互作用,可以降低压缩比.     

单元法教学改革经验总结

近年来,在国家教委教学基本要求的精神指导下,全国各院校都在物理实验教学改革方面做了大量的工作,也涌现了一批各具特色,不同风格的教学体系,提供了很好的教学经验。从1985年以来,我校在物理实验教学改革方面也进行了一系列的探索与尝试。我们认真研究了国内兄弟院校教学改革的经验,仔细分析了国外物理实验教学情况,通过总结自已实践的经验,决定建立适合本校实际情况,有利于提高教学质量和加强能力培养的,有自己特色的普通物理实验教学体系和实施办法。自1987年2月以来,我们实施了以单元法教学为基础     

低温胁迫下香蕉叶片Chla荧光动力学参量的变化及其品种差异性

低温胁迫下,广东2号香蕉品种和巴西香蕉品种Williams的叶绿素(Chla)荧光动力学参量F_Ⅴ/F_m、ΔF_Ⅴ/F_T以及williams品种的F_IV/F_Ⅴ均呈下降趋势,两个品种的荧光上升半时间T_1/2及广东2号的F_IV/F_Ⅴ呈上升趋势.其中,Williams的F_Ⅴ/F_m、ΔF_Ⅴ/F_T和T_1/2的变化幅度小于广东2号,表明低温胁迫通过抑制光合电子传递速度和PSⅡ无活性中心含量的提高使香蕉叶片PSⅡ原初光能转换效率下降,相同低温对广东2号的影响大于对Williams的影响.F_Ⅴ/F_m和ΔF_Ⅴ/F_T可以作为评价香蕉幼苗抗冷性的物理指标.     

Photoluminescence Characterization of Nanocrystalline ZnO Array

High-density and uniform well-aligned ZnO sub-micron rods are synthesized on the silicon substrate over a large area. The morphology and structure of the ZnO sub-micron rods are investigated by x-ray diffraction, transmission electron microscopy and Raman spectra. It is found that the ZnO sub-micron rods are of high crystal quality with the diameter in the range of 400-600 nm and the length of several micrometres long. The optical properties were studied by photoluminescence spectra. The results show that the intensity of the ultraviolet emission at 3.3eV is rather high, meanwhile the deep level transition centred at about 2.38eV is weak. The free exciton emission could a/so be observed at low temperature, which implies the high optical quality of the ZnO sub-micron rods.This growth technique provides one effective way to fabricate the high crystal quality ZnO nanowires array, which is very important for potential applications in the new-type optoelectronic nanodevices.     

自然的边界：物理学的第二课程狭义和广义相对论以及量子力学

人们对广义相对论和量子力学的公共渴求是无止境的，我们除了竭力地吸引学生的这种学习愿望外(这些学生大多数不会成为物理专业工作者，但所有的学生都可以经历“深奥的物理学”)，还必须选择地应用它。理科、工科和数学学科的学生每个人都熟知微积分，     

二维光学神经网络自由空间互连结构设计

本文分析了以透镜阵列元件建立空间互连通道的光学神经网络中神经元数的理论极限.为了提高网络中的神经元数,我们提出了一种并行结构设计,该结构克服了小透镜成象中的离轴象散的影响,提高了系统的光能利用效率,同时降低了系统中的对位精度误差,提高了互连运算精度.     

Magnetic Properties of Melted ThMn12-Type Carbides and Their Nitrides

The carbides of NdDy0.2Fe12-yMoyC0.6 （y = 1.5, 2） crystallized in the ThMn12-type structure have been successfully synthesized by arc melting method, followed by a heat treatment. The magnetic properties are strongly enhanced with the addition of carbon. Upon the carbonation the saturation magnetization Ms is increased by about 20emu/g and the Curie temperature Tc is enhanced by 40-70K. The spin reorientation （SR） temperature decreases from 125 K for NdDy0.2Fe10Mo2 to 55 K for NdDy0.2Fe10MO2C0.6 indicating the change of magnetocrystalline anisotropy in the Nd sublattice. It is found that the intrinsic magnetic properties of the carbides can be improved by further nitrogenation, The composite carbon-nitrogen compounds show a Tc - 560K, M8 - 105 emu/g and Ha （anisotropy field） - 86kOe for NdDy0.2Fe10Mo2Co.6Nz and a Tc- 628K, M8 - 119 emu/g and Ha - 115kOe for NdDy0.2Fe10.5Mo1.5C0.6Nz. These magnetic properties are even better than those of simple nitrides, suggesting that these compounds can be considered as a good candidate for permanent magnet applications.