Partially Classical States of a Boson Field

Employing positive-definiteness arguments we analyse Boson field states, which combine classical and quantum mechanical features (signal and noise), in a constructive manner. Mathematically, they constitute Bauer simplexes within the convex, weak-*-compact state space of the C*-Weyl algebra, defined by a presymplectic test function space (smooth one-Boson wave functions) and are affinely homeomorphic to a state space of a classical field. The regular elements are expressed in terms of weak distributions (probability premeasures) on the dual test function space. The Bauer simplex arising from the bare vacuum is shown to generalize the quantum optical photon field states with positive P-functions.     

双光束相干控制产生多次谐波的实验验证

利用两束相干度可改变的飞秒脉冲光对产生的五次谐波的强度特性进行了研究，发现谐波信号的强度随相干程度的增大而增加，谐波信号的最大值相对于相干零点(双光束相干度最大处)是非对称的，从而证明了合成的激光脉冲波形变化对谐波信号的影响.同时对谐波的受激放大理论进行了初步的实验探索和展望. 关键词： 五次谐波 波形变化 相干 受激放大     

Letter: Note on Invariants of the Weyl Tensor

Algebraically special gravitational fields are described using algebraic and differential invariants of the Weyl tensor. A type III invariant is also given and calculated for Robinson-Trautman spaces.     

水力机械内鲤鱼草鱼的压力损伤模拟试验

通过试验人工模拟水力机械内压力变化过程,测量压力时间变化,观察并解剖分析不同压力变化过程对鲤鱼和草鱼造成损伤的情况。试验发现,负压状态下的压力变化过程会对鱼的生存构成直接威胁,并得到了新型环保水力机械设计中应采用的压力时变导数极限值。     

一般线性模型下方差最小范数二次无偏估计的稳健性

本文给出了一般线性模型下,由最小二乘得到的方差估计与最小范数二次无偏估计相等的充分必要条件,并且当Gauss-Markov估计与最小二乘估计相等时,可以得到一个简单的等价条件。     

试题质量评价研究

教学过程的规范化管理是保证教学质量的重要手段。考试是对教和学的效果的检验，是教学过程管理规范化必须要解决的问题，一直受到教学管理部门的重视，采取了多项措施解决有关问题，其中一个重要的手段是采用试题库。在采用试题库时，必须要有高质量的试题作保证。本探讨基于KDD技术的试题质量评价方法和指标，并通过实例来说明其有效性。     

On the even power mean of a sum analogous to Dedekind sums

Summary Our purpose is to extend results due to P. Chandra and L. Leindler concerning the order of approximation by means of Fourier series for functions belonging to generalized Lipschitz-classes.     

利用拉曼型的Jaynes-Cummings模型传送两比特的未知原子态

实现量子态的隐形传送、尤其是多比特量子态的隐形传送在量子信息领域中有非常重要的作用，提出了一种隐形传送两比特未知原子态的方案，在此方案中，用两个两粒子纠缠态代替一个三粒子纠缠态作为量子信道，而且此方案可推广到隐形传送N比特的未知原子态。     

The solvability conditions for inverse eigenproblem of symmetric and anti‐persymmetric matrices and its approximation

The problem of generating a matrix A with specified eigen‐pair, where A is a symmetric and anti‐persymmetric matrix, is presented. An existence theorem is given and proved. A general expression of such a matrix is provided. We denote the set of such matrices by ??????_Eⁿ. The optimal approximation problem associated with ??????_Eⁿ is discussed, that is: to find the nearest matrix to a given matrix A* by A∈??????_Eⁿ. The existence and uniqueness of the optimal approximation problem is proved and the expression is provided for this nearest matrix. Copyright © 2002 John Wiley & Sons, Ltd.     

多束速调管的增益带宽

 研究了M个束、N个共振腔的多束速调管(MBK)的增益和带宽，得到了描述小信号增益和带宽与器件结构参数和电子束参数关系的公式，给出了在不同参数下增益随频率的变化曲线。分析了多腔对增益，多束对带宽的影响。计算结果表明：多腔可以提高增益；多束可以降低Q值，从而可以增中带宽，带宽增加工了3.6%，还可以提高增益；对于MBK，频率交叉调谐对增加带宽不如频率调谐好；空间电荷波只对增益有影响，对带宽没有影响。最后，预估一种L带多束速调管的增益带宽为8.1%。