相对论密度泛函法对CN^—在铜和银电极上振动频率的研究

对ＣＮ＾－在铜和银电极上的吸附性质进行了相对论密度泛函簇模型计算。结果表明，电场微扰方法可以描述ＣＮ＾－在铜和银电极上吸附的表面现象，电极势诱导的频率移动被理解为Ｓｔａｒｋ效应所引起。内振动模式Ｍ－ＣＮ和Ｃ－Ｎ的耦合对电位诱导的Ｃ－Ｎ振动频率变化的大小起重要作用，计算所得的由Ｓｔａｒｋ效应所引起Ｃ－Ｎ振动频率变化的斜率和实验结果相符。     

舰船红外搜索跟踪系统发展展望

红外搜索跟踪系统具有角分辨精度高、隐蔽性好、探测能力强、抗电磁干扰能力强等优点,在舰船预警探测领域得到了广泛的应用。详细介绍了舰船红外搜索跟踪系统的工作原理、分类及舰船红外搜索跟踪系统的发展现状,最后总结了舰船红外搜索跟踪系统的发展趋势。     

漂移的星系

围绕银河系运转的小星系大麦哲伦星云，正在以相对于我们自己的星系每秒378±18千米的速度运动。天文学家用哈勃太空望远镜跟踪观测了这个星系相对于21个遥远类星体的运动情况，这是迄今为止最精确的天文测量数据。     

基于激光二极管光反馈效应的肌肉震颤测量系统

介绍一种测量肌肉震颤频率和幅度的无损伤、非接触光学方法。分析了在直接频率调制下 ,激光二极管中的光反馈效应 ,探讨了振动微小位移和速度的理论模型。设计并研制了一套基于光反馈效应的直接频率调制激光二极管光电探测系统。利用该系统对微弱机械振动信号进行了探测 ,表明该系统能用于肌肉震颤的测量。最后介绍了人体前臂内侧屈肌群紧张收缩时 ,肌肉震颤的光学测量结果     

对巯基苯胺分子表面增强拉曼光谱的密度泛函理论研究

采用密度泛函理论(density functional theory,DFT),在B3LYP/6-31++-G** (C,H,N,S)/LANL2DZ(Ag)水平上,对对巯基苯胺(p-aminothiophenol,PATP)分子进行了几何结构优化,计算了 PATP的常规拉曼散射(normal Raman scatte...     

谈谈‘9’的乘积巧算

多位数9乘任何数，运算起来并不难，但不论是‘加1乘’，还是‘跟踪乘’，拨珠次数都较烦琐。我在工作中摸索出一种巧算方法，也可称它为‘规律法’。现奉献给广大珠算卫作者和珠算爱好者。     

基于FPGA的DDS设计方法

介绍了一种基于FPGA的DDS设计方法,结合DDS的原理,给出了具体设计程序以及仿真波形。基于FPGA的DDS与传统的专业DDS芯片相比具有电路简单、输出波形调整灵活以及性价比高等特点。     

Cubature Kalman filters: Derivation and extension

This paper focuses on the cubature Kalman filters （CKFs） for the nonlinear dynamic systems with additive process and measurement noise. As is well known, the heart of the CKF is the third-degree spherical–radial cubature rule which makes it possible to compute the integrals encountered in nonlinear filtering problems. However, the rule not only requires computing the integration over an n-dimensional spherical region, but also combines the spherical cubature rule with the radial rule, thereby making it difficult to construct higher-degree CKFs. Moreover, the cubature formula used to construct the CKF has some drawbacks in computation. To address these issues, we present a more general class of the CKFs, which completely abandons the spherical–radial cubature rule. It can be shown that the conventional CKF is a special case of the proposed algorithm. The paper also includes a fifth-degree extension of the CKF. Two target tracking problems are used to verify the proposed algorithm. The results of both experiments demonstrate that the higher-degree CKF outperforms the conventional nonlinear filters in terms of accuracy.     

Auditory filter based broadband MUSIC algorithm for sound source localization

Based on the analysis of the shortcomings of broadband MUSIC algorithm with short-time Fourier transform （SF-MUSIC） for sound source localization, a broadband MUSIC algorithm with auditory filter （AF-MUSIC） was proposed. The proposed algorithm first em- ploys auditory filter bank to decompose the signals received on the microphone array, and then locates the sound source with MUSIC algorithm over every frequency channel. At last, by combining with the subinterval frequency estimation, the final localization result is gained. Evaluations on the proposed algorithm prove that comparing with the SF-MUSIC algorithm, the AF-MUSIC algorithm decreases the average error of the estimation results with 2.5479 de- gree in different source conditions. The accuracy of sound source DOA estimation is enhanced effectively.