单模光纤中光孤子与准光孤子传输特性研究

阐述了光学孤子的产生背景和基本理论，着重论述了光孤子形成的机理和光孤子的基本性质。分析了光孤子传输时所服从的标准非线性薛定谔方程和修正的非线性薛定谔方程并进行了数值模拟，得出了一些非常有意义的结果。最后系统地研究了Hasegawa等人提出的准光孤子概念，给出了准光孤子通信系统的组成、原理及影响光孤子通信的诸多因素并给出了相应地解决办法。     

非线性再生散度模型的广义变离差检验

研究了非线性再生散度模型的广义变离差检验,对于一类常见的正则散度分布族,解决了离差参数的齐性检验问题,得到了检验的似然比统计量和score统计量,并证明了score统计量的渐近χ2性.本文研究的非线性再生散度模型包括了许多常见的统计模型,诸如正态线性和非线性回归模型、广义线性模型和广义非线性模型等;同时,本文结果也适用于某些更复杂的分布,诸如基于极值分布、单纯形分布的非线性模型等.因此本文的结果进一步推广和发展了文献中已有的工作.     

Transitional phenomenon of particle dispersion in gas-solid two-phase flows

Without using any turbulent model, direct numerical simulation of a three-dimensional gas-solid two-phase turbulent jet was performed by finite volume method. The effects on dispersion of particles with different Stokes numbers by the transitional behavior of turbulent structures were investigated. To produce high-resolution results and reduce the computation and storage, the fractional-step projection algorithm was used to solve the governing equations of gas phase fluid. The low-storage, three-order Runge-Kutta scheme was used for time integration. The governing equations of particles were solved in the Lagrangian framework. These numerical schemes were validated by the good agreement be-tween the statistical results of flow field and the related experimental data. In the study of particle dis-persion, it was found that the effects on particle dispersion by the spanwise vortex structures were prominent. The new behaviors of particle dispersion were also observed during the evolution of the flow field, i.e. the transitional phenomenon of particle dispersion occurs for the particles with small and intermediate Stokes numbers.     

稠油分散体系中黏度与化学组成的灰熵关系分析

采用灰色关联熵分析法研究了稠油黏度及其族组成、有机杂原子、金属元素和主要官能团的关联,探讨了物系黏度随稠油分散系统微观结构的变化规律.结果表明:①沥青质是影响稠油黏度的最主要的因素,稠油体系中沥青质聚集分相的形成特性取决于稠油体系的物理结构,即稠油胶体构造的稳定性.胶体稳定性越高,沥青质越不容易从稠油分散体系中聚集沉淀.②在沥青质分子单元叠积过程中,由沥青质的杂原子因素、过渡金属因素、芳香环结构因素和脂肪性侧链因素共同决定的化学作用的影响是第一位的,其中芳香环结构因素和杂原子因素的影响最为显著,而由稠油体系不稳定性构成的物理作用的影响则居于次要地位.     

棱镜材料与其色散研究及应用

采用汞灯光谱谱线波长为已知数据,测量其通过三棱镜后所对应的各最小偏向角,求出其对应的折射率n值,进而作出色散曲线,验证其所满足的函数关系,在此基础上用图解插值法求其钠光谱谱线波长.     

Numerical Investigation of the Impact of Different Configurations and Aspect Ratios on Dense Gas Dispersion in Urban Street Canyons

The dispersion of chlorine gas in urban street canyons was numerically simulated using the fire dynamics simulator, a code developed by the National Institute of Standards and Technology of USA, which uses large eddy simulation coupled with the Smagorinsky sub-grid scale model. The unsteady flow fields were computed by solving the filtered incompressible Navier-Stokes equations under low Mach number ap-proximation by the finite difference method. The studies analyzed the influence of different street canyon configurations and aspect ratios on the flow and chlorine gas dispersion. The geometric configuration and aspect ratio both affect the vortices and the local concentration distributions in street canyons.     

浅谈公共建筑安全疏散

公共建筑安全疏散,其目的主要是使人能从发生事故的建筑中,迅速撤离到安全部位(室外或避难层、避难间等),及时转移室内重要的物资和财产,同时,尽可能地减少火灾造成的人员伤亡与财产损失,也为消防人员提供有利的灭火条件等。     

城市大气环境的数值模拟

空气质量是城市可持续发展的保证,是改善人居环境的重要条件之一。大气环境是多尺度的流体运动,本文介绍了城市尺度和居民小区尺度大气环境的现代数值预测方法——大涡数值模拟方法,着重说明该尺度下复杂环境流动的特点和数值模拟需要注意的问题,例如下垫面的处理方法、边界条件的合理提法等;以典型城市和模型小区为例,说明数值预测方法的应用,展示不同下垫面对城市大气环境的影响、风速与小区空气质量的关系等。     

固相原位接枝炭黑的制备及其在涂料中的应用

采用固相原位接枝反应方法将炭黑(CB)与有机小分子在Haake转矩流变仪中进行接枝反应,制得接枝炭黑(GCB)。通过原子力显微镜(AFM)观察发现该接枝炭黑呈单分散分布,粒径为30 nm左右。将接枝炭黑制得涂料并考察其对涂料性能的影响,结果表明:与用未接枝炭黑制得的涂料相比,接枝炭黑制得的涂料在光泽度、附着力等方面均有较大提高。同时,扫描电子显微镜(SEM)也观察到接枝炭黑在涂料中均匀分散,且达到纳米级。     

喀斯特水示踪模型研究

本文提出了两个喀斯特管流场和一个渗流场示踪模型,并给出了它们的解析解和应用分析以及对它们的识别原理和方法。