The study and applications of photochemical-dynamical gravity wave model I

A two-dimensional, nonlinear, compressible, diabatic, nonhydrostatic photochemical-dynamical gravity wave model has been advanced. The model includes diabetic process produced by photochemistry and the effect of gravity wave on atmospheric chemical species. In the horizontal direction, the pseudospectral method is used. The finite difference approximations are used in vertical direction z and time t. The FICE method is used to solve the model. The model results on small amplitude fluctuation are very close to those of linear theory, which demonstrates the correctness of the model.

     

计算机辅助物理实验教学的几点思考

探讨了物理实验教学引入智能化仪器的必要性和意义，指出引入计算机辅助教学必须对传统的实验教学内容和方法重新设计，同时软件的设计应给学生留有接口的余地。     

The study and applications of photochemical-dynamical gravity wave model II

A nonlinear, compressible, non-isothermal gravity wave model that involves photochemistry is used to study the effects of gravity wave on atmospheric chemical species distributions in this paper. The changes in the distributions of oxygen compound and hydrogen compound density induced by gravity wave propagation are simulated. The results indicate that when a gravity wave propagates through a mesopause region, even if it does not break, it can influence the background distributions of chemical species. The effect of gravity wave on chemical species at night is larger than in daytime.     

DISCRETE HUYGENS' MODELLING APPROACH TO WAVE PROPAGATIONS IN A HOMOGENEOUS ELASTIC FIELD

The application of the discrete Huygens' modelling has been discussed for acoustic wave propagation problems, in which the scalar wave field problems have been focused. The present paper extends the application of the modelling to the elastic wave propagation in a homogeneous elastic medium in which two types of waves, the longitudinal wave and the shear wave, are independent except at the boundary. Each wave can be treated like a scalar wave until the two waves reach the boundary where they couple so as to satisfy the displacement or stress boundary condition. We propose the approach confining ourselves to the two-dimensional field. Some examples are demonstrated, whose solutions are compared with the vectorial wave modelling and finite difference modelling solutions whenever they are available.     

A Promising MoO_x-based Catalyst for n-Heptane Isomerization

The increasing demand for higher-octane gasoline and the regulations limiting the amount of aromatics in the fuel motivate the interest in catalytic isomerization of n-alkanes. In the last ten years, transition metal oxides or oxycarbides based on molybdenum or tungstate have attracted much attention due to their high activity and isomerization selectivity compared to the conventional bifunctional supported platinum catalyst and high resistance to sulphur and nitrogen catalyst poisons1-5. Ma…     

处理原子-辐射场相互作用系统的变分方法

用Heisenberg-Weyl(简H-W)群直积SU(2)群上的相干态表述了原子-辐射场相互作用系统的非平衡态统计力学.引入一个新定义的含时分布函数,将非平衡态下密度矩阵所满足的von Neumann方程转化成可分离变量的偏微分方程,给出了方程的形式解,算符的平均值表示.本文还就便于作微扰展开的相互作用绘景作了讨论.     

关于《一类奇异边值问题的正解》的注记

文[4]通过构造反例断言文[1]中定理的必要性证明有误,本文首先指出文[4] 的这个断言不正确,然后对文[4]中定理2.1作了本质性的改进.     

N2（A）及N（2D）对IF（X）的传能研究

在微波放电系统中,对NH_3-F-F_2-CF_3I体系进行研究,结果表明,向IF(X)传能的诸多媒介中,N_2(A)及N(~2D)起着主要作用,并且这一结论在经微波激发后的N_2与CF_3I的直接反应中得到了进一步证实。     

氩气介质阻挡放电的发光特性

本文使用水电极介质阻挡放电装置,采用光学方法测量了氩气介质阻挡放电的发光特性。发现在驱动电压处于一定的范围内时,放电处于丝极模式,在驱动电压的每半周期内,无论是放电的总光还是单个微通道的放电发光均只有一次脉冲,单个微放电的时间为2μs,而总放电时间为2.4μs,这表明在氩气的丝极模式中,各单丝产生与熄灭的时间极其接近,各个放电丝之间有着很好的时间相关性。最后将本文的结果与空气中介质阻挡放电丝极模式的发光特性相比较,空气放电在每半周内的总光信号由多个脉冲组成,而每一个脉冲对应多个放电丝,因而氩气中各个放电微通道之间的时间相关性远强于空气的情况。     

质量控制图原理在股票投资组合中的应用研究

质量控制图是用来控制生产过程质量的一种统计方法。其基本理论方法应用到股票投资组合中,可以降低投资风险,提高投资组合的收益率。通过实证研究表明:利用质量控制图原理来确定投资组合的选股、买点和卖点,可以使投资组合获得明显高于大盘指数的收益率,从而验证了质量控制图的基本理论方法完全可以应用于股票投资决策,并且具有显著的实际应用价值。