Implicit Scheme for Stochastic Parabolic Partial Diferential Equations Driven by Space-Time White Noise

We extend Rothe's method of solving linear parabolic PDEs to the case of nonlinear SPDEs driven by space-time white noise. When the nonlinear terms are Lipschitz functions we prove almost sure convergence of the approximations uniformly in time and space. When the nonlinear drift term is only measurable we obtain the convergence in probability, by using Malliavin calculus.     

公路交通噪声阈限值的分析研究

本文采用客观测量和主观评价相结合的方法研究公路交通噪声对人的影响。通过研究，求得了公路交通噪声扰民的容忍阈值，分析了比较了公路交通噪声各种客观评价量与人的主观评价量的之间的相互关系。     

具有色关联的色噪声驱动下单模激光线性模型的随机共振

研究了具有指数形式关联的两色噪声驱动下单模激光线性模型受信号调制后其输出信噪比，发现了随机共振现象.根据计算结果讨论了噪声（即噪声强度、噪声间互关联程度和关联时间）和信号（信号频率和信号振幅）对信噪比的影响. 关键词： 随机共振 噪声关联时间 信噪比     

Effects of traffic noise on paserine populations in Mediterranean wooded pastures

The effect of traffic noise on the breeding density of 20 passerine species was examined over a 2-year period in three different road types passing through pasture-woodlands in western-central Spain. No statistically significant differences were observed during the 2 years studied. An average of 19.6 birds/10 ha was recorded for the low-traffic road (LT), 21.7 birds/10 ha for the medium-traffic road (MT) and 19.1 birds/10 ha for the high-traffic road (HT). A total of 11 species (55%) did not show any statistically significant differences in breeding density among the different types of roads. By contrast, other species, such as the Blackbird, the Iberian Shrike and the Linnet, did point to differences between the MT and HT roads. House and Rock Sparrows, as well as the Corn Bunting, showed higher breeding densities near the HT road. The opposite effect was observed for the Wheatear, the Iberian chiffchaff and the Woodlark, for which high breeding densities were recorded in the vicinity of the LT road. Our results suggest that traffic noise constitutes a serious problem for at least 15% of the breeding bird community.     

掺铒光纤放大器在多路模拟光纤传输系统中应用

对应用掺铒光纤放大器的副载波频分复用模拟电视光纤传输系统的噪声和失真进行了实验研究，利用掺铒光纤放大器作为系统的功率提升和中继放大器，分别成功地进行了１８５ｋｍ和２１５ｋｍ的系统传输试验     

光子计数剪切干涉仪波前探测自适应光学系统噪声分析

在自适应光学系统中，波前探测器的噪声是主要误差源。针对我们建立的２．１６ｍ望远镜红外自适应光学系统，从伺服控制系统的角度分析了光子计数噪声及其在系统闭环过程中的传递，从理论上推导了系统的噪声功率谱、伺服传递函数以及开环和闭环噪声公式。另外，还给出了在系统中实测的开环和闭环噪声     

光纤克尔门全光再生器特性分析

讨论了光纤克尔门再生器抑制输入光脉冲的加性噪声和脉冲中心抖动的机制，分析了再生器中各元件的配置对其抑制噪声能力的影响。指出根据通信线路中心的噪声特性，适当选择克尔门中色散位移光纤长度，可以大大抑制通信系统中的噪声，提高系统通信容量。     

Numerical simulations of stochastic differential equations

A simple, very accurate algorithm for numerical simulation of stochastic differential equations is described. Its relationship to colored noise is elucidated and exhibited by explicit results. The especially delicate problem of mean first passage times is highlighted and highly accurate agreement between the numerical simulations and analytic results are shown.     

Analytic solution of the mean spherical approximation for ion-dipole model in a neutralizing background

The analytic solution of the mean spherical approximation (MSA) for a multicomponent mixture of hard ions and hard dipoles with arbitrary valences and sizes of particles in a uniform neutralizing background is found. Expressions for the pair correlation functions and thermodynamics in the MSA are obtained.     

On the structure of competitive societies

We model the dynamics of social structure by a simple interacting particle system. The social standing of an individual agent is represented by an integer-valued fitness that changes via two offsetting processes. When two agents interact one advances: the fitter with probability p and the less fit with probability 1-p. The fitness of an agent may also decline with rate r. From a scaling analysis of the underlying master equations for the fitness distribution of the population, we find four distinct social structures as a function of the governing parameters p and r. These include: (i) a static lower-class society where all agents have finite fitness; (ii) an upwardly-mobile middle-class society; (iii) a hierarchical society where a finite fraction of the population belongs to a middle class and a complementary fraction to the lower class; (iv) an egalitarian society where all agents are upwardly mobile and have nearly the same fitness. We determine the basic features of the fitness distributions in these four phases.