综合流动和传热的废轮胎回转窑热解模型

废轮胎在回转窑内的热解主要受到气-固相流动、传质和传热及化学反应动力参数等因素的影响。在对回转窑 内固体颗粒运动、传热传质进行分析的基础上,结合对轮胎热解反应动力学的研究,发展了综合流动、传热的废轮胎回转 窑热解模型,可计算得到回转窑内热解的温度分布、物料转化率、产物得率等。模型计算结果与试验结果吻合较好。     

碳黑颗粒生长模型的初步研究

本文利用反应类(Reaction Class)概念和矩(Moment)方法,研究了层流预混甲烷火焰中碳黑颗粒的成核与长大过程。模型综合考虑了颗粒的成核、颗粒间由于碰撞的聚合、以及气态组分在颗粒表面的生长。通过数值计算预报了碳黑颗粒平均粒径、总表面积、体积分数和数密度,以及萘(A4)和乙炔(C2H2)在颗粒表面的增长速率。     

考虑信号灯影响的交通流模型与数值模拟

基于信号灯交通系统中跟车行为的特点,改进了现有跟车方程,提出一个考虑信号影响的交通流模型.数值计算结果表明,该模型可以很好地再现车流的聚集与消散、停车波和启动波的演化规律及传播特性,证明模型是合理有效的. 关键词： 交通流模型 信号灯 停车波 启动波     

基于滑速比的气水两相流气相流量计算方法研究

目前对气水两相流的分相流量的研究中,多是针对两相流总流量和液相分相流量进行,对气相分相流量的研究很少.本文利用文丘里管和含气率传感器对空气水两相流气相流量计算方法进行了研究,在均相流模型基础上考虑了滑速比因素造成的影响,探讨了两相流气相流量计算方法.结果表明,该方法相对于传统的均相流模型在计算精度上得到了显著提高.     

Characterizing localization properties of two spinless electrons in a one-dimensional Harper model with concurrence

By mapping the Fock space of many local fermionic modes isomorphically onto a many-qubit space and using the measure of concurrence, this paper studies numerically the mode entanglement of two spinless electrons with on-site interaction U moving in the one-dimensional Harper model. Generally speaking, for electrons in extended regimes （potential parameter λ 〈 2）, the spectrum-averaged concurrence N（C） first decreases slowly as A increases until its local minimum, then increases with λ until its peak at λ = 2, while for electrons in localized regimes （λ 〉 2）, N（C） decreases drastically as λ increases. The functions of N（C） versus λ are different for electrons in extended and localized regimes. The maximum of N（C） occurs at the point λ= 2, which is the critical value in the one-dimensional singleparticle Harper model. From these studies it can distinguish extended, localized and critical regimes for the two-particle system. It is also found for the same λ that the interaction U always induce the decreases of concurrence, i.e., the concurrence can reflect the localization effect due to the interaction. All these provide us a new quantity to understand the localization properties of eigenstates of two interacting particles.     

CIELAB与CIECAM02色空间均匀性比较研究

采用均匀色空间Munsell系统检验和验证了CIELAB和色貌模型CIECAM02色空间的均匀性。利用Mun- sell色卡所对应的三刺激值X,Y,Z作为模型的输入值,预测色空间模型的明度、彩度和色调,并通过预测结果比较和检验了CIELAB色空间和CIECAM02模型色空间的均匀性。研究表明:在预测明度方面,两个色空间的结果相似;在预测彩度时,CIECAM02模型较好于CIELAB色空间;在预测色调时,当色调逐渐从BG变化到B时,CIELAB所预测的色调角与由Munsell色空间计算出来的色调角之差逐渐增大,最大时超过6%,而CIECAM02所预测的色调角与Munsell色空间的色调角之差在2.5%以内,CIECAM02优于CIELAB色空间。     

改进的基于主成分分析的三维人脸形状建模

针对基于主成分分析(PCA)的三维(3D)人脸形状重构不精确的缺点,对位移向量、缩放因子、旋转矩阵、重构系数等参数进行了精确的定义和计算,并对重构模型进行了有效的调整。根据CVL Face Database建立了113个3D人脸形状模型,经迭代运算后重构出了由特征点组成的稀疏3D人脸形状模型。利用径向基函数(RBF)得到了密集3D人脸形状模型。试验结果表明,算法可以得到精确的重构模型,对深度旋转的人脸图像和特征点定位误差也有很好的鲁棒性。     

红外视景仿真技术及其研究进展

从红外视景仿真技术意义出发，介绍了其所包含的几个基本部分；从目标辐射建模、背景辐射建模和大气建模三方面，总结了国内外红外视景仿真技术发展历程和状况。其中列举了国外多个典型红外视景仿真软件和几个较完善红外辐射模型，并统计了2000年以来国内高校在红外视景仿真方面的研究情况。统计数据表明，多个发达国家的红外视景仿真技术已逐步趋于成熟和产品化，而国内尚未开发出功能较完善的红外视景仿真系统，只能仿真较简单场景。     

Higher Dimensional Unified Description of Early Universe with Variable <Emphasis Type="Italic">G</Emphasis> and Λ

A homogeneous and isotropic Friedmann-Robertson-Walker (FRW) model with varying gravitational and cosmological constant is studied in the context of higher dimensional space time. Exact solution of the field equations are obtained by using the “gamma law” equation of state p=(γ−1)ρ, where γ is adiabatic parameter varies continuously as the universe expands. The functional form γ which is assumed to be the function of scale factor R as proposed by Carvalho (1996) is used to analyse the behavior of scale factor R, cosmological constant Λ and the gravitational constant G for two different phases: inflation and radiation. The various physical aspects of the early cosmological models has also been discussed in the framework of higher dimensional space time.     

Massive and massless neutrinos on unbalanced seesaws

The observation of neutrino oscillations requires new physics beyond the standard model (SM).A SM-like gauge theory with p lepton families can be extended by introducing q heavy right-handed Majorana neutrinos but preserving its SU(2)L x U(1)y gauge symmetry.The overall neutrino mass matrix M turns out to be a symmetric (p+q) x (p+q) matrix.Given p＞q,the rank of M is in general equal to 2q,corresponding to 2q non-zero mass eigenvalues.The existence of (p-q) massless left-handed Majorana neutrinos is an exact consequence of the model,independent of the usual approximation made in deriving the Type-I seesaw relation between the effective p x p light Majorana neutrino mass matrix M,and the q x q heavy Majorana neutrino mass matrix MR.In other words,the numbers of massive left- and right-handed neutrinos are fairly matched.A good example to illustrate this "seesaw fair play rule"is the minimal seesaw model with p ＝ 3 and q ＝ 2,in which one masslese neutrino sits on the unbalanced seesaw.