有界F-支撑函数和类空Wulff形

给定H_+~n上适合凸条件的正函数F,对L~(n+1)中具有非退化Gauss映射的类空超曲面引入了Θ_F曲率.对适当的F,本文证得:具有常Θ_F曲率,且F-支撑函数介于两个负常数之间的类空超曲面必是类空Wulff形.在F=1的情况下,对H_i/H_n为常数的类空超曲面也建立了类似的唯一性结果.     

Theoretical Study on the Propagation of Acoustic Phonon Modes in Single-Wall Carbon Nanotubes by Different Potential Models

Propagation of a heat pulse in （10,0） zig-zag carbon nanotubes, modeled by the Brenner-H and Tersoff bondorder potentials, respectively, is investigated using a molecular dynamics simulation. The longitudinal acoustic mode, twisting phonon mode, and second sound waves are observed in the simulation. The time variations of speed and intensity of the above three phonon modes are in good agreement with the previous works based on the Brenner-I potential. Higher speed and weaker peak intensity are observed in the simulation of the Tersoff potential. The inherent over-binding of radicals and the non-local effects in Tersoff＇s covalent-bonding formula may play an important role in the heat pulse propagating simulation.     

DAIP改性环氧树脂研究

采用共固化的方法,得到酚醛环氧树脂(F-51)和间苯二甲酸二烯丙基酯(DAIP)的共固化树脂。实验结果表明:DAIP的加入降低了F-51环氧树脂的粘度[体系粘度为150～350mPa·s(25℃)],利于工艺操作;提高了F-51环氧树脂的耐热性,热变形温度达200℃。研究了F-51环氧树脂和DAIP共固化的固化行为、不同配比对共固化物形态结构的影响;并研究了不同配比对固化物耐热性的影响。     

广义F-互补问题及其与变分不等式问题的等价性

在Banach空间中引入了一类广义F-互补问题,研究了它与一类变分不等式问题的等价性关系,给出了此类变分不等式问题的解的存在唯一性定理.     

构造和评价奖惩系统的新方法

当知道一个奖惩系统的等级和保费水平时,利用信息熵提出并得到奖惩系统的理想概率分布．在保单中考虑人身伤亡索赔次数的二元模型,将奖惩系统的平稳概率分布与理想概率分布的差异,通过卡方值与多余度分别表现出来,将其作为评价奖惩系统的一个新工具．     

四色猜想的解析论证及其在地图绘制中的应用

依据欧拉定理,研究了边数差和着色数计算公式,对四色猜想进行了研究．借助四面体顶点数与面积数相等的原则、多面体边数不变的原则和多余理论,用边数差数学计算方法论证了四色猜想．用简单的数学公式和几何作图方法说明了四色猜想的合理性,为其提供了可靠的理论依据．用“三色包点”和“以面切体”的几何作图法,证明多面体和平面地图的着色数恒为4;非三色包点的图形,可以通过“以面切体”的方法转换成三色包点的图形;使用多余国家、多余边数的数学技巧代替计算机使用的不可避免性、可约性是合适的．理论分析及实例论证表明该方法简单可行．     

F-本质子模与F-多余子模

本文研究了F-本质子模和F-多余子模.利用同调的方法,得到了F-本质与F-包络,F-多余与F-复盖之间的关系,另外还得到了F-本质子模,F-多余子模的相关性质,从而推广了文献[3,10]中的部分结果.     

Evolution of the 251 cm-1 temperature in infrared phonon mode with Ba0.6K0.4Fe2As2

The far-infrared optical reflectivity of an optimaUy doped Ba1-xKxFe2As2 （x = 0.4） single crystal is measured from room temperature down to 4 K. We study the temperature dependence of the in-plane infrared-active phonon at 251 em-1. This phonon exhibits a symmetric line shape in the optical conductivity, suggesting that the coupling between the phonon and the electronic background is weak. Upon cooling down, the frequency of this phonon continu- ously increases, following the conventional temperature dependence expected in the absence of a structural or magnetic transition. The intensity of this phonon is temperature independent within the measurement accuracy. These observa- tions indicate that the structural and magnetic phase transition might be completely suppressed by chemical doping in the optimally doped Bao.6Ko.4Fe2As2 compound.     

A Generalization of F-Expansion Method and Its Application to （2＋l）-Dimensional Boussinesq Equation

A new generalized F-expansion method is introduced and applied to the study of the （2＋1）-dimensional Boussinesq equation. The further extension of the method is discussed at the end of this paper.     

The Periodic Wave Solutions for Two Nonlinear Evolution Equations

By using the F-expansion method proposed recently, the periodic wave solutions expressed by Jacobi elliptic functions for two nonlinear evolution equations are derived. In the limit cases, the solitary wave solutions and the other type of traveling wave solutions for the system are obtained.