A Class of Sequential Blind Source Separation Method in Order Using Swarm Optimization Algorithm

We consider the problem of sequential, blind source separation in some specific order from a mixture of sub- and sup-Gaussian sources. Three methods of separation are developed, specifically, kurtosis maximization using (a) particle swarm optimization, (b) differential evolution, and (c) artificial bee colony algorithm, all of which produce the separation in decreasing order of the absolute kurtosis based on the maximization of the kurtosis cost function. The validity of the methods was confirmed through simulation. Moreover, compared with other conventional methods, the proposed method separated the various sources with greater accuracy. Finally, we performed a real-world experiment to separate electroencephalogram (EEG) signals from a super-determined mixture with Gaussian noise. Whereas the conventional methods separate simultaneously EEG signals of interest along with noise, the result of this example shows the proposed methods recover from the outset solely those EEG signals of interest. This feature will be of benefit in many practical applications.     

LD端面泵浦Nd：YVO_4激光器及其高阶横模的工作特性

报道了ＬＤ端面泵浦Ｎｄ：ＹＶＯ_４激光器的实验结果，获得了２３．６％的光－光转换效率，相应的斜效率为２８．８％。特别对在泵浦光与腔模匹配欠佳时高阶横模的起振特性作了比较详细的实验研究和定性讨论。     

半导体激光泵浦掺钕铍酸镧固体激光器

报道了用国产二极管激光端面泵浦自行研制的掺铵铍酸镧（Ｎｄ：ＢＥＬ）晶体得到１．０７μｍ线偏振激光输出的研究结果。分别用非球面透镜成像、加棱镜对扩束、加光纤传输三种方式将泵浦光耦合到增益介质中，由此得到不同的斜效率，并对此作了分析。     

输出千瓦级基模CO_2激光的七折光学谐振腔

报道了一种成功地在横向磁场约束的直流辉光放电激励横向流动ＣＯ２激光器上输出千瓦级基模光束的七折腔的结构、参数及实验结果，并对其进行了讨论。     

原发性纤毛运动障碍电镜观察

本文报道一例原发性纤毛运动障碍患者的超微结构表现，该例病人具有典型的Ｋａｒｔａｇｅｎｅｒ氏综合征的临床表现，电镜观察到支气管粘膜上皮纤皮弯曲倒伏，部分相互融合，发育不主发，可呈连体状，质膜有丝状突起，有的纤毛呈正方形或多角形，中央及周围微管缺失，移位和增加，内外动力臂缺失，本文对该病的超生病理学进行了讨论。     

A Study of the Parasitic Properties of the Schottky Barrier Diode

In this paper, we present a newly designed parameter extraction method of the Schottky barrier diode (SBD) with the purpose of measuring and studying its parasitic properties. This method includes three kinds of auxiliary configurations and is named as three-configuration parameter extraction method (TPEM). TPEM has such features as simplicity of operation, self-consistence, and accuracy. With TPEM, the accurate parasitic parameters of the diode can be easily obtained. Taking a GaAs SBD as an example, the pad-to-pad capacitance is 7 fF, the air-bridge finger self-inductance 11 pH, the air-bridge finger self-resistance 0.6 Ω, and the finger-to-pad capacitance 2.1 fF. A more accurate approach to finding the value of the series resistant of the SBD is also proposed, and then a complete SBD model is built. The evaluation of the modeling technology, as well as TPEM, is implemented by comparing the simulated and measured I-V curves and the S-parameters. And good agreements are observed. By using TPEM, the influence of the variation of the geometric parameters is studied, and several ways to reduce the parasitic effect are presented. The results show that the width of the air-bridge finger and the length of the channel are the two largest influencing parameters, with the normalized impact factors 0.56 and 0.29, respectively. By using TPEM and the modeling technology presented in this paper, a design process of the SBD is proposed. As an example, a type of SBD suitable for 500–600 GHz zero-biased detection is designed, and the agreement between the simulated and measured results has been improved. SBDs for other applications could be designed in a similar way.     

基于对偶四元数的圆锥及划船误差补偿改进算法

为提高高动态环境下的对偶四元数捷联惯性导航算法解算精度,将梯形数字积分算法应用于圆锥和划船误差补偿算法中,改进了姿态和速度解算算法,提高了对偶四元数捷联惯性导航算法的解算精度。在单个采样周期内,利用前一时刻采集的陀螺角速率信号和当前时刻采集的陀螺角速率信号,通过梯形积分方式计算角增量进行圆锥误差补偿;利用前一时刻采集的加速度计信号和当前时刻的加速度计信号,通过梯形积分方式计算速度增量并结合同一时刻的角增量进行划船误差补偿。通过设计的多组动态模拟仿真航迹验证表明,当角速率和比力作为圆锥和划船误差补偿算法输入时,梯形积分算法的精度高于传统的矩形积分算法,且航迹的动态性越高,改进算法的性能优势越显著。同时,通过动态跑车实验结果的分析对比,进一步验证了该改进算法的实用性。     

齿轮钢18Cr2Ni4WA磨削烧伤实验及仿真预测研究

18Cr2Ni4WA钢以其韧性好和强度高的特点,广泛使用于螺旋伞齿轮等重载齿轮的生产与制造。磨齿作为齿轮加工的最后工序,磨削区域较高温度场容易引起磨削烧伤发生,使加工表面质量和疲劳寿命难以保证。针对齿轮钢18Cr2Ni4WA磨削烧伤问题,设计SG砂轮磨削实验,研究其发生磨削烧伤时表面形貌、显微硬度的变化规律,并通过有限元仿真预测烧伤层深。研究结果表明：当砂轮速度为20.3 m/s、工件速度为0.03 m/s、磨削深度大于0.05 mm时工件发生磨削烧伤,随着磨削深度的增加,烧伤程度加重,磨削表面氧化层颜色由淡黄色转为褐色最后呈现青色,表面形貌由纹理清晰转为涂覆;工件产生回火烧伤时,产生硬度较低的回火索氏体;烧伤层深的仿真模拟值与实验测量值基本吻合,验证了有限元仿真对磨削烧伤预测的可行性。