Dynamical Behavior of Core 3 He Nuclear Reaction-Diffusion Systems and Sun''s Gravitational Field

The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos.     

关于“二阶非线性泛函微分方程解的振动性质”一文的一点注记

文中就文1所讨论的二阶非线性泛函微分方程x″(t) p(t)x′(t-τ(t)) q(t)f(x(τ(t))=0的解的振动性质,利用文2的已知结果改进了文1的相应结果。     

转动系统的微幅振荡

由力学积分变分原理导出了第二类拉格朗日方程，得出了转动系统微幅振荡的运动微分方程组，求出了系统相对平衡状态应满足的条件，且讨论了微弱转动对正则振型的型态和频率的影响，得到了频率修正表达式．     

一类具有偏差变元的双曲偏泛函微分方程的H-振动性

本文研究了一类具有连续偏差变元带中立项的双曲偏泛函微分方程解的H-振动性,给出了判别解H-振动的充分条件.这里H是Rm中单位向量.     

高阶中立型偏微分系统的振动性分析(英文)

研究了一类具连续时滞和非线性扩散项的高阶中立型偏微分系统的边值问题,利用积分平均技巧和Riccati方法将高维振动问题转化为一维振动问题,建立了该类边值问题在Dirichlet边界条件下所有解振动的若干新的充分判据。     

一类具有连续变量的偶数阶中立型差分方程的振动性

研究了一类具有连续变量的偶数阶中立型差分方程的振动性,通过利用累次积分变换和一些新的技巧,给出了这类方程的一些振动准则。     

An improvement index to quantify the evolution of performance in running

Abstract

Improvements in track and field sports have been attributed to factors such as population increase, drugs and new technologies, but previous research has found it difficult to distinguish the contributions from specific influences. Here it is shown how this is possible by means of a performance improvement index based on useful work done combined with modelling of the annual top 25 performances. The index was set to 100 in 1948 and showed that, by 2012, it had increased in running events to between 110.5 and 146.7 (men’s 100 m and marathon). Underlying global effects accounted for the majority of all improvements (16.2 to 46.7) with smaller influences attributable to an influx of African runners (3.6 to 9.3), and a 4 -year oscillation that arose from staging of the Olympic Games (±0.2 to ±0.6). Performance decreased with the introduction of compulsory random drug testing (?0.9 to ?3.9) the World Anti-Doping Agency (WADA; ?0.5 to ?2.5) and fully automated timing (?0.6 to ?2.5). Changes in elite sporting performance since the 1890s are attributable to societal changes caused by the industrial revolution and globalisation superimposed on millennia of human evolution.     

一维线性谐振子的波函数和几率密度作图方法探讨

针对一维线性谐振子教学中的难点,阐述了如何利用厄密多项式的递归或递推公式,通过计算机画出线性谐振子的波函数和几率密度曲线.既方便了多媒体的教学,又加深了学生对一维线性谐振子的理解.最后对几种绘图方法的特点进行了讨论.     

强激光场下NH_3分子波包演化和粒子数布居研究

计算了质量加权坐标系下NH3分子基态、激发态和离子基态势能面,研究了基态波包演化情况以及波包在基态激发态之间布居情况.通过研究证实了NH3分子存在拉伸振动,同时发现基态、激发态粒子数布居存在拉比振荡现象.     

具高阶Laplace算子的非线性中立抛物型方程的强迫振动性

讨论一类具高阶Laplace算子的非线性中立型抛物偏微分方程的强迫振动性,给出了这类方程在三类不同边值条件下所有解振动的若干新的充分性判据.所得结果推广和包含了已知的一些结果.