4维完备Einstein流形的一些注释

本文给出了在开的定向的4维流形上存在有界曲率的完备Einstein度量的障碍．     

具连续变量脉冲差分方程解的振动性

考虑新的一类具有连续变量的脉冲差分方程x(t τ) - x(t) p(t)x(t - rτ) =0,x(tk τ) - x(tk) = bkx(tk),　t≥t0 -τ,t≠tk,t∈N(1),其中p(t)是[t0 -τ,∞]上的非负连续函数,τ>0,bk 是常数,r是正整数, 0≤t0 < t1 < t2 <…< tk <…且limk→∞tk =∞,获得了方程所有解振动的充分条件.     

有源RLC电路量子化的双波描述

采用正则变换量子化以及规范变换方案,得到有源RLC电路量子化哈密顿算符及其波函数.引入双波函数描述其量子状态,得到了电荷、电流等物理量的时间演化方程.对有源RLC电路给出更完整的描述.     

PPS抽样回归估计量及其在两相抽样中的应用

本文针对交通运输量抽样调查中存在的波动系数问题，讨论在ＰＰＳ的抽样条件下，回归估计量的构造及其在两相抽样中的应用     

六层加侧混合型摇摆器磁场的理论计算与数值模拟

 利用文献[1，2]给出的结果，提供了六层加侧混合型摇摆器中永磁体磁场的计算公式和软铁磁场计算的积分方程式。对周期长度lw =1.6cm，磁极间隙g=0.5cm的情况，计算了单向聚焦和双向聚焦两种不同构形的磁场分布，并得到了g /lw =1/3条件下，峰值磁场Bw超过1特斯拉的设计指标。     

片式消声器的设计及其在环境噪声控制中的应用

本文从应用角度，对片式消声器的结构，消声机理，设计原则等作了较为全面的阐述，介绍了应用实例，结合工程实践，提出了一个估算存在气流时消声系数的经验公式。     

*-Representations of Twisted Generalized Weyl Constructions

We study bounded and unbounded *-representations of Twisted Generalized Weyl Algebras and algebras similar to them for different choices of involutions.     

On General Volume-Preserving Mechanical Systems via Cohomology

We present the general form of equations that generate a volume-preserving flow on a symplectic manifold(Μ,ω) via the highest Euler-Lagrange cohomology. It is shown that for every volume-preserving fiow there are some 2-forms that play a similar role to the Hamiltonian in the Hamilton mechanics and the ordinary canonical equations with Hamiltonian H are included as a special case with a 2-form Hω/(n - 1).     

Superconvergence of Continuous Finite Elements with Interpolated Coeffcients for Initial Value Problems of Nonlinear Ordinary Differential Equation

In this paper, n-degree continuous finite element method with interpolated coefficients for nonlinear initial value problem of ordinary differential equation is introduced and analyzed. An optimal superconvergence u-uh = O(hn+2), n ≥ 2, at (n + 1)-order Lobatto points in each element respectively is proved. Finally the theoretical results are tested by a numerical example.