过模介质O-波导的传播特性

本文详细分析了过模介质O-波导的全部模式,提出一种简单准确的模式分类法,导出了各本征模分离的特征方程,避免了直接求解复杂的特征方程。讨论了按场分布划分的三类正规模:表面模、界面模和泄漏模以及它们的传播特性,给出了相应的近似解。几个极限结果与文献十分吻合。研究表明,适当选择过模介质O-波导的材料参数和波导尺寸,它的传播特性很容易控制。     

光合色素分子吸附膜的非线性增强效应

吸附在光学表面上的细菌叶绿素和藻兰素生物分子膜.在基波(λ=1.06μm)激光作用下,观察到谐波效应.文中对藻兰素只产生三次谐波而不产生二次谐波做了分析.     

对硝基苯磺酰基乙酸酯与α,β—不饱和酸酯类化合物在固液…

在固液相转移催化（Ｋ２ＣＯ３／ＤＭＦ／ＴＥＢＡ）条件下，对硝基苯磺酰基乙酸酯与α、β－不饱和酸酯反应意外地生成加成重排产物。其反应机理可能是砜酯首先与α、β－不饱和酯起Ｍｉｃｈａｅｌ反应，随后加成物发生分子内芳环上的新核性取代，酸化后脱去ＳＯ２得最终产物。     

用立体李萨如图形测频率

在用李萨如图形测频率时，若待测频率与参考频率相差太大，则示波器上的李氏图形尤其是边缘区太拥挤，不易观测切点数目。本提出采用具有立体感的李萨如图形，就可以解决上述问题。     

增益饱和在啁啾脉冲放大中的影响

研究了增益饱和在啁啾脉冲放大中的影响，发现由于增益饱和在存在，压缩后脉冲的信噪比会下降，而且展宽器附加的色散也会降低输出的信噪比，这种降低对应着一定的光谱畸变。通过对展宽／压缩器作用的分析，提示了啁啾脉冲放大中光谱与光强的内在联系，提出利用非共振放大来修正光谱畸变提高放大压缩后的信噪比。     

关于丢番图方程(ax~m±1)/(ax±1)=y~n与(ax~m±1)/(ax±1)=y~n+1

本文证明了方程(1.4)没有x是一个n次完全幂的整数解(a,x,y,m,n),从而推广了乐茂华的结论:方程(1.1)没有x是一个n次完全幂的整数解(x,y,m,n),并有条件的得到了方程(1.5)的全部解.     

心动周期性多普勒波形的平均方法

许多临床上有用的多普勒小以形都是随时产是变化的，但又近似于周期心动周期的周期信号。为准确估计这些多普靳波形，并提取主同灵敏度的特征参数，有必要对它们按心吉期进行平均。     

大气环境质量评价的灰色模型

大气环境是一个包含未知信息的灰色系统，根据其灰色性．运用灰色系统理论可以克服目前一些环境质量评价方法（综合指数法、概率统计法、模糊综合评判法）的局限性，使评价结果更为科学和客观。     

Quantum Fluctuation of Mesoscopic Capacitance Coupled Circuit in a Thermal Vacuum State

The quantum fluctuations of mesoscopic capacitance-coupled circuit in thermal vacuum state are investigated by using the theory of thermal field dynamics on the basis of quantization of the mesoscopic circuit. It is shown that under a definite temperature, the fluctuations of electric charges and currents change with temperature. The higher the temperature, the more quantum noise the coupled circuit exhibits.     

Simulation of Helium Behaviour in Titanium Crystals Using Molecular Dynamics

The behaviour of helium in Ti crystals at 300 K has been investigated by means of the molecular dynamics. The study is focused on the influences of He-Ti interaction on the aggregation of helium atoms in the substrate. When a Born-Mayer potential is used to describe the He-Ti interaction, the He atoms are unable to cluster with each other due to the weak bridge barrier that cannot trap the helium atoms, Whereas using a He-Ti potential that is constructed by fitting the ab initio pairwise He-Ti potential, the clustering of He atoms can be observed. The results indicate that suitable He-Ti potential plays an important role in the formation of He clusters in metals. Moreover, it is noted that the shape of the formed He cluster is irregular, and the produced defect prefers to congregating on one side of the He cluster rather than spreading symmetrically around it.