多模光纤不同模式布里渊散射参数

基于射线光学和波动光学理论分析了多模光纤的布里渊散射特性,提出了确定布里渊散射角取值范围的方法;推导了阶跃型和渐变型多模光纤不同模式群布里渊频移、线宽、散射谱和散射功率的表达式.结果表明,阶跃型和渐变型多模光纤布里渊散射角的最大取值范围为全反射临界角的2倍到π;阶跃型光纤的布里渊频移、线宽、归一化峰值增益和散射功率随模式群的变化比渐变型光纤缓慢,且随着模式群编号的增加,阶跃型光纤的上述参量分别在11.084~10.932GHz、21.760~21.168 MHz、1~0.933和1.990×10-9~1.857×10-9 W范围内呈曲线下降;渐变型光纤的上述参量分别在11.064~10.969GHz、21.683~21.314MHz、1~0.957和2.052×10-9~1.965×10-9 W范围内呈直线下降.     

随机波动率跳跃扩散模型下复合期权定价

复合期权是一类以期权作为标的物的奇异型合约,它已广泛应用于许多金融实践。本文在股价满足一类随机波动率及跳跃均存在于股价和波动率的仿射跳跃扩散模型下(也称随机波动率混合跳跃扩散模型)考察了复合期权的定价。应用二维特征函数和Fourier反变换方法获到了标的为欧式标准看涨期权的欧式复合看涨期权的定价半封闭公式,并将其应用于推导扩展期权的定价。最后,借助于离散快速Fourier变换法(FFT)数值计算定价公式,并用数值实例分析了期权价格对波动率的敏感性。数值结果表明扩散波动和跳跃波动对期权价格都有正的影响,而且跳跃波动的冲击非常显著。     

Novel correction method for X-ray beam energy fluctuation of high energy DR system with a linear detector

A high energy digital radiography (DR) testing system has generated diverse scientific and technological interest in the field of industrial non-destructive testing. However, due to the limitations of manufacturing technology for accelerators, an energy fluctuation of the X-ray beam exists and leads to bright and dark streak artifacts in the DR image. Here we report the utilization of a new software-based method to correct the fluctuation artifacts. The correction method is performed using a high pass filtering operation to extract the high frequency information that reflects the X-ray beam energy fluctuation, and then subtracting it from the original image. Our experimental results show that this method is able to rule out the artifacts effectively and is readily implemented on a practical scanning system.     

A New 3D Four-Wing Chaotic System with Cubic Nonlinearity and Its Circuit Implementation

A new 3D four-wing smooth autonomous chaotic system in which each equation contains a cubic product term is presented and physically implemented. Spectral analysis shows that the four-wing chaotic attractor has extremely wide frequency bandwidth compared with that of the Lorenz system and other four-wing chaotic systems, which is important in some relevant engineering applications such as secure communications.     

从人文素质教育角度，探讨大学语文与思想品德整合的现实性和实施途径

如何利用有限的课时，使人文素质教育取得最大的教育效果，一直是理工科院校努力探索解决的一个重要问题。本文从大学生精神成人的角度，以普世价值观为准则，对大学语文和思想品德课的课程目标进行分析，探索如何把品德课中抽象的理论和大学语文中的生动形象结合起来，力图用熏陶感染代替空洞说教，使学生更容易接受，更好实现教育功能。     

Carrier－Envelop Phase－Dependent Effect on Photoelectron Angular Distribution in Single－Cycle Laser Pulses ＊

Using a nonperturbative scattering theory, We study the photoelectron angular distributions (PADs) of Kr atoms irradiated by an infinite sequence of intense single-cycle pulses of circular polarization. We demonstrate the inversion asymmetry of PADs and the dependence of PADs on the carrier-envelop phase of the single-cycle pulses. The inversion asymmetry is caused by the interference between transition channels where the different channels are characterized by different combinations of absorbed-photon numbers in the ionization process. Our results provide a possible method to determine the value of carrier-envelop phase by the detected PADs.     

双参数变形量子代数SU（1，1）_（q，s）的Nodvik实现和Holstein—Primakoff实现

给出了双参数变形量子代数ＳＵ（１，１）ｑ，ｓ的Ｎｏｄｖｉｋ实现和Ｈｏｌｓｔｅｉｎ－Ｐｒｉｍａｋｏｆｆ实现，并给出了ＳＵ（１，１）ｑ，ｓ，和双参数变形振子的变形映射。     

长水波近似方程的多孤子解

利用直接而简单的齐次平衡方法，给出了长水波近似方程的多孤子解.本方法可进一步推广研究一大类非线性波动方程. 关键词：     

Nonlinear Internal Damping of Wave Equations with Variable Coefficients

For wave equations with variable coefficients on regions which are not necessarily smooth, we study the energy decay rate when a nonlinear damping is applied on a suitable subrigion.