关于群布尔矩阵的收敛和周期

在文[1]和[2]中,各自得到了如下结果：一个循环布尔矩阵A是本原的当且仅当gcd（i2-i1,…,i1-i1,n）＝1,其中A＝Pi1十Pi2十…＋Pi1,0≤i1＜i2＜…＜i1≤n-1,P是对应于n阶循环置换（123…n）的置换矩阵．在本文中,先把此结果推广到群矩阵（一种循环矩阵的推广）．其次,讨论群布尔矩阵的周期．给出了计算周期的算法,最后,探讨循环布尔矩阵A的使Am p＝Am的最小正整数m.     

负载型钼基催化剂上甲烷,乙烷无氧芳构化反应研究

研究了不同载体钼基催化剂上甲烷，乙烷的无氧芳构化反应。在所采用的载体中，ＨＺＳＭ－５具有最佳性能，对甲烷的芳构化反应，Ｍｏ／ＨＺＳＭ－５催化剂表现出较高的活性和芳烃选择性；而Ｍｏ／Ａｌ２Ｏ３或Ｍｏ／ＳｉＯ２催化剂则相对较差。对于乙烷的反应，钼物种的存在更有利于甲烷或乙烯的生成，芳烃选择性相对较低。钼物种较强的断键能力可能是使甲烷Ｃ－Ｈ键活化的原因。     

纳米二氧化硅物理吸附乙醇的密度泛函研究

利用密度泛函理论, 采用周期性边界条件及簇方法研究了无定型纳米二氧化硅的表面结构以及其对小分子吸附物乙醇的吸附性质. 计算结果表明, 小簇模型在研究特定种类的吸附方面具有优势, 而周期性切片模型更能真实地反映纳米二氧化硅的表面环境; 乙醇在二氧化硅表面的吸附主要依赖于氢键作用, 并倾向于充当氢键受体的角色.     

Concomitance in single bubble sonoluminescence of period doubling in emission and shape distortion

We report the first direct observation for a single stable sonoluminescing bubble of a shape instability. Furthermore we show that stable saturation of the shape distortion caused by the instability for a certain range of parameters is experimentally possible and furthermore is directly linked to the curious phenomenon of flash by flash period doubling of the sonoluminescent emission as the afterbounce instability causing the shape distortion is always period doubled whenever the emission is & vice versa.     

线宽增强因子对外光注入半导体激光器非线性单周期振荡特性的影响

线宽增强因子是影响半导体激光器输出特性的一个重要参量,不同材料不同结构类型的半导体激光器的线宽增强因子有较大的差异.利用光注入半导体激光器的单模速率方程模型,数值研究了线宽增强因子对外光注入半导体激光器的非线性单周期振荡特性的影响.结果表明:外光注入半导体激光器的动态特性对线宽增强因子的变化极为敏感,随着线宽增强因子的增加,在负失谐注入范围内单周期振荡区域显著增大,同时注入锁定的稳态输出被大大抑制.分析了线宽增强因子对非线性单周期振荡光谱特性和振荡频率的影响,结果表明:随着半导体激光器线宽增强因子的增大,单周期振荡的频率越大|当线宽增强因子不变时,单周期振荡的频率随注入光强度和频率失谐的增加而增加.     

Measurement of period difference in grating pair based on analysis of far-field intensity patterns

We propose and demonstrate an experimental method for measuring the period difference in grating pair. The method uses the compensating relationship between line-density difference and the Littrow-angle difference of gratings. Far-field intensity patterns of 0th- and −1st-orders diffraction beams are monitored for alignment during the angle measurement. For a pair of ∼0.676 μm period gratings, the relative period difference was measured to be 798.4 × 10⁻⁶ with a standard deviation of 2.0 × 10⁻⁶.     

Higher Order Approximation of the Period-energy Function for Single Degree of Freedom Hamiltonian Systems

In 1985 Franz Rothe [J. Reine Angew Math. 355 (1985) 129–138] found, by means of the thermodynamical equilibrium theory, an asymptotic estimate of the period of solutions of ordinary differential equations originated by predator–prey Volterra–Lotka model. We extend some of the Rothe's ideas to more general systems:

On the busy period of a multichannel Markovian queue

For a multichannel Markovian queue with infinite waiting space the density function of the busy period is obtained in series form by using simple induction.The expression obtained can be used to find easily the moment of the length of the –channel busy period of any arbitrary order in an explicit form.     

On the Recursive Sequence x n+1 = α + (βx n−1)/(1 + g(xn ))

We investigate the boundedness character, the oscillatory and periodic nature and global attractivity of the nonnegative solutions of the difference equation where the parameters α and β are nonnegative real numbers and g(x) is a continuous function on [0, ∞), which satisfies some additional conditions.     

旋转摆的周期单调性

考虑了一类旋转摆系统.该系统拥有至多5个周期轨族,通过计算椭圆积分得到了参数在不同取值范围内该系统各个周期轨族的周期单调性.该文的分析过程也为讨论这类周期单调性问题提供了一个比Abel积分更基本的方法.最后给出的数值仿真结果映证了文中的结论.