箱覆盖问题的半定松驰算法

箱覆盖问题是NP困难问题中的经典问题，得到了广泛地研究，九十年代以来，半定松驰策略被用来求解组合优化问题，取得了很好的结果[13]，本文首次给箱覆盖问题的半定松驰算法，算法的理论分析结果表明它适合于求解大规模的箱覆盖问题。     

溅射功率对多层膜质量的影响

用磁控溅射技术制备薄膜，用X射线衍射研究在基片和靶间距离固定的情况下不同的溅射功率对薄膜结构的影响。结果表明：过低的溅射功率下淀积的薄膜有畸变的X射线衍射特征峰，特征峰强度小，半峰全宽大。而比较高溅射功率得到的薄膜有比较尖锐的X射线衍射特征峰，强度高和半峰全宽非常窄。研究表明，X射线衍射特征峰强度小和半峰全宽大的薄膜结构疏松，而强度高和半峰全宽非常窄的薄膜结构致密。     

受激喇曼散射在掺铒光纤放大器中的影响

本文在分析了均匀掺杂分布式光纤放大器（d－EDFA）的基础上，提出了沿传输方向掺杂浓度单调下降（单变），和降升结合（两变）的两种渐变型分布式光纤放大器，并用传输方程研究了透明传输和最佳掺杂浓度下，受激喇曼散射对均匀、单变和两变型三种d－EDFA的各种特性的影响．     

一类广义积分integral from n=0 to ∞(((sin(θ_x))/x)~ndx)的计算

利用三角函数幂公式、L′Hospital法则、分部积分公式,得到含有三角函数的第一类广义积分integral from n=0 to ∞(((sin(θ_x))/x)~ndx)的计算公式,其中n≥1且θ≠0.     

Collective mechanism for nuclear stopping and transverse flow in heavy-ion collisions

The role of filamentation instability of quark-gluon plasma, in explaining collective phenomena in relativistic heavy-ion collisions, has been analyzed. Using equations of SU(2) two fluid color hydrodynamics it is shown that this instability can significantly enhance nuclear stopping and might contribute to collective sideward flows.     

X波段五腔渡越管振荡器的理论与实验研究

 提出了一种新结构的X波段五腔渡越管振荡器，进行了理论和实验研究。根据场分布进行了一维非线性分析，结果表明该结构可以产生高功率微波，并判断了工作模式，为TM₀₁模的3π/5模。采用粒子模拟验证了一维非线性分析的结论，并优化设计出五腔渡越管振荡器,优化结果为：输出功率约1 GW， 工作频率9.3 GHz，束波转换效率约22%。实验中，通过参数调节，得到频率约9.25 GHz，峰值功率约780 MW，脉宽（半高宽）21 ns的输出微波，束波转换效率约为16%。实验结果与模拟结果基本符合。     

Limit Regimes of Braking of Disc-Type Composite Flywheels Made by Filament Winding

A set of invariants describing the limit regimes of braking disk-type wound composite flywheels is suggested. The limit regime is determined by using a linear failure criterion. It is shown that, for generating short-time impulses of very high power, a set of small identical flywheels is more effective than one large flywheel with an equivalent mass. Particular examples illustrating the theory considered are discussed.     

激发对相干态的等阶Y压缩效应

用数值计算法研究了激发对相干态|ζ;m〉＝a^+mb^+m|ζ〉的等阶Y压缩效应.结果表明:对于态a^+mb^+m|ζ〉,光场存在着等阶K(＝2,3,4,5,…)次方Y压缩效应,但是随着场模上光子增加数m的增大,等阶K次方Y压缩效应减弱.     

On the stationary Lp-approximation power to derivatives by radial basis function interpolation

In this paper, we consider approximation to derivatives of a function by using radial basis function interpolation. Most of well-known theories for this problem provide error analysis in terms of the so-called native space, say C_φ. However, if a basis function φ is smooth, the space C_φ is extremely small. Thus, the purpose of this study is to extend this result to functions in the homogenous Sobolev space.     

Covering group and graph of discretized volumes

We consider a discretized volume V consisting of finite, congruent and attached copies of a tile t. We find a group L _V the orbit of which, when applied to t, is just V. We show the connection between the structural matrixQ in the formal solution of a boundary value problem formulated for volume V and the so called auxiliary matrix of the graph Γ _v associated with V. We show boundary value problems to be isomorphic if the graphs associated with the volumes are isomorphic, or, if the covering groups are Sunada pairs.