EXACT CONTROLLABILITY FOR FIRST ORDER QUASILINEAR HYPERBOLIC SYSTEMS WITH ZERO EIGENVALUES＊＊＊

For a class of mixed initial-boundary value problem for general quasilinear hyperbolic sys-tems with zero eigenvalues, the authors establish the local exact controllability with boundary controls acting on one end or on two ends and internai controls acting on a part of equations in the system.     

两个图的积的S-不可收缩性(英)

本文从组合角度明确给出了两个图的积是S-不可收缩的特征．     

双障碍问题阻尼牛顿法的二阶收敛性

本文研究由双障碍问题导出的一类B可微函数的性质，并在一定条件下证明了求解相应的B可微方程阻尼牛顿法的全局收效性和二阶收效性．数值例子表明这一算法是有效的．     

二阶Melnikov函数及其应用

在Ｍｅｌｎｉｋｏｖ函数的种种应用中，目前常见到的仅是一阶形式。本文具体推导了二阶Ｍｅｌｎｉｋｏｖ函数的分析表达，提出了临界情况下考察双曲鞍点的稳定流形与不稳定流形相对位置的二阶判据，并成功地用于环面ｖａｎｄｅｒＰｏｌ方程的研究中。     

高能物理学发展的回顾和展望

 从电弱统一理论提出到现在已经过去了23年.量子色动力学从诞生到现在也已经历了17年,在这期间CERN建成了E_cm=60GeV的质子对撞机ISR;FNAL和CERN分别建成了能量为500GeV和450GeV的质子同步加速器.     

Effect of Magnetic Field and Equilibrium Flow on Rayleigh-Taylor Instability

We investigate the effect of a finite equilibrium flow and magnetic field on the Rayleigh-Taylor instability. It is found that the equilibrium flow only makes a frequency shift of perturbation and the growth rate of the Rayleigh-Taylor instability remains unchanged. However, the magnetic field can change the growth rate and, in particular,a very strong magnetic field suppresses the growth rate.     

误差杆的概念及其应用

介绍了误差杆的概念及其在实验作图中的应用。     

Do the Experimental Violations of Bell Inequalities Require a Non-Local Interpretation of Quantum Mechanics？

Since the data show that Bell inequalities are violated experimentally, we must conclude that any hidden variable theory （which correctly predicts experimental data ） will be non-local. But, to conclude that the experimental violations of Bell inequalities show quantum mechanics to be non-local is unjustified. Specifically, the key assumptions required to obtain a Bell inequality are （ 1 ） locality and （2） the assignment of meaningful （ non- negative） probabilities to seemingly physical correlations （Bell expresses these correlations via ＂ hidden variables＂ ）. Since the Bell inequality is violated by experiment, at least one of these assumptions is wrong. The widespread conclusion that locality must be relinquished is valid only if we retain the previously mentioned correlations （ ＂hidden variables＂ ）. We will demonstrate that the latter are not physical observables - they are not elements of physical reality.