线性回归系数最小二乘估计弱相合性的一个结果

假定线性回归模型的误差列为i.i.d.,有r阶矩,1≤r＜2.[1]中证明若     

弱耦合LC电路节拍振荡的实验现象

对弱耦合LC电路的节拍振荡现象进行了计算机模拟研究,由此可以加深学生对这一物理现象的现解。     

阻尼振动的回复时间最短时所满足的条件

本文指出在讨论阻尼振动的回复时间时必须要考虑仪器的测量精度才有意义,而且并非临界阻尼运动的回复时间最短,而是本文所定义的“弱阻尼振动的临界状态”的回复时间最短,进而导出了在给定测量精度时最短回复时间所满足的方程。     

向量拟平衡问题系统及其应用

引入了向量拟平衡问题系统并证明了其解的存在性定理．作为应用,还得到约束多目标对策和无约束多目标对策弱Pareto平衡的一些存在性结果．     

超子的稀有衰变及CP不守恒

简述了近些年来超子稀有衰变的理论和实验研究进展及其待解决的问题。简单地讨论了兰州CSR上进行超子稀有衰变实验的可能性。A brief review is given on recent studies of hyperon rare decay both in theory and experiment. Some problems which exist in the field are presented. A possibility of study on the rare decay of Hyperon ∑^＋ at CSR is discussed.     

The solution of the time-dependent Fokker--Planck equation of non-degenerate optical parametric amplification and its application to the optimum realization of EPR paradox

In this paper, the solution of the time-dependent Fokker--Planck equation of non-degenerate optical parametric amplification is used to deduce the condition demonstrating the Einstein--Podolsky--Rosen (EPR) paradox. The analytics and numerical calculation show the influence of pump depletion on the error in the measurement of continuous variables. The optimum realization of EPR paradox can be achieved by adjusting the parameter of squeezing. This result is of practical importance when the realistic experimental conditions are taken into consideration.     

Tau Leptonic Decay τ→lVlVτ in Littlest Higgs Model＊

We consider the τ leptonic decay $\tau\rightarrow l\bar{\nu}_{l}\nu_{\tau}$ in the framework of the littlest Higgs (LH) model and calculate the corrections of new particles to this decay. We find that the contributions of the charged scalars can be safely ignored and the LH model is in perfect agreement with the universality of the couplings of the SU gauge bosons to the leptonic charged currents. The corrections of the LH model to the τ leptonic decay $\tau\rightarrow l\bar{\nu}_{l}\nu_{\tau}$ are not sensitive to the parameter c, but depend strongly on the parameters f and x. The precision measured data about the τ leptonic decay demand that the parameter f approximately equal 3.5 TeV and x>0.1, while agree with the general expectation based on other phenomenological explorations.     

弱界面ZnO-SiO2-Si压电层合结构中的Love波

建立了考虑弱连接界面特性的传递矩阵,基于状态空间法分析了弱界面压电层合结构中Love波的传播特性,揭示了ZnO-SiO2-Si层间的弱界面位置和特性对Love波相速度的影响,研究发现频率较高的第零阶Love波对靠近表面的弱界面更敏感,当频率趋于零和无穷时,弱界面的特性和位置对Love波第零阶的相速度没有影响.第一阶Love波的相速度在截断频率附近受弱界面影响相对显著,当频率趋于无穷时,弱界面的特性和位置对Love波第一阶的相速度影响越来越小.     

A computational study of the wing–wing and wing–body interactions of a model insect

The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.     

分片试验与有限元法

提出分片试验在有限元法中有着重要的作用,它是近代有限元发展的一个主要特色。得出分片试验对位移和应变函数的要求,这些要求便是一个好的有限元法所应保证的;分析了几何方程弱形式与分片试验的关系,借此分析了杂交元、拟协调元如何满足这些要求,以及在满足这些要示的同时产生的对其他条件的影响;分析了精化直接刚度法、广义协调元和双参数法如何保证分片试验的满足;最后作为位移条件的应用例子,改进了ＢＣＩＺ元。