Identification of Elastic Orthotropic Material Parameters by the Singular Boundary Method

This article addresses the resolution of the inverse problem for the parameter identification in orthotropic materials with a number of measurements merely on the boundaries. The inverse problem is formulated as an optimization problem of a residual functional which evaluates the differences between the experimental and predicted displacements. The singular boundary method, an integration-free, mathematically simple and boundary-only meshless method, is employed to numerically determine the predicted displacements. The residual functional is minimized by the Levenberg-Marquardt method. Three numerical examples are carried out to illustrate the robustness, efficiency, and accuracy of the proposed scheme. In addition, different levels of noise are added into the boundary conditions to verify the stability of the present methodology.     

不确定混沌系统的反同步与参数辨识

针对一类混沌系统,提出了一种系统的混沌反同步设计方案,基于该方案,设计一种自适应控制方法,实现了参数不确定系统的混沌反同步和未知参数的辨识.数值模拟结果表明了提出方法的有效性.     

拉曼光谱在优化处理绿松石中的应用研究

优化处理绿松石的大量面市,给绿松石的鉴定带来了挑战。通过激光拉曼光谱测试分析、压制及人工注塑处理绿松石为研究对象,对优化处理绿松石的激光拉曼光谱特征进行了研究。结果表明,拉曼光谱技术是一种有效鉴别绿松石及其处理品的无损检测方法,OH,H₂O,PO₄ 及CH₂基团的振动模式和频率决定了优化处理绿松石的激光拉曼光谱特征。优化处理绿松石除具绿松石典型拉曼光谱特征外,在2 937和2 883 cm-1处普遍出现一组具鉴定意义的由外来添加物中CH₂伸缩振动及CH₂弯曲振动致拉曼谱带。依据这些特征拉曼谱带,有助于将天然绿松石与优化处理品区分开。该研究为快速、准确、无损鉴别绿松石提供了一种新思路。     

Who is whistling? Localizing and identifying phonating dolphins in captivity

Acoustic communication through whistles is well developed in dolphins. However, little is known on how dolphins are using whistles because localizing the sound source is not an easy task. In the present study, the hyperbola method was used to localize the sound source using a two-hydrophone array. A combined visual and acoustic method was used to determine the identity of the whistling dolphin. In an aquarium in Mexico City where two adult bottlenose dolphins were housed we recorded 946 whistles during 22 days. We found that a dolphin was located along the calculated hyperbola for 72.9% of the whistles, but only for 60.3% of the whistles could we determine the identity of the whistling dolphin. However, sometimes it was possible to use other cues to identify the whistling dolphin. It could be the animal that performed a behavior named “observation” at the time whistling occurred or, when a whistle was only recorded on one channel, the whistling dolphin could be the animal located closest to the hydrophone that captured the whistle. Using these cues, 15.4% of the whistles were further ascribed to either dolphin to obtain an overall identification efficiency of 75.7%. Our results show that a very simple and inexpensive acoustic setup can lead to a reasonable number of identifications of the captive whistling dolphin: this is the first study to report such a high rate of whistles identified to the free swimming, captive dolphin that produced them. Therefore, we have a data set with which we can investigate how dolphins are using whistles. This method can be applied in other aquaria where a small number of dolphins is housed; though, the actual efficiency of this method will depend on how often dolphins spend time next to each other and on the reverberation conditions of the pool.     

虹膜身份识别技术

介绍了现在最有发展前景的生物特征识别技术——虹膜身份识别技术。在整体介绍了其技术的基础上,详细介绍了当今具有代表性的虹膜识别算法,最后针对虹膜识别技术存在的主要问题分析了虹膜识别的发展方向：精度高、速度快、鲁棒性好的定位算法,高效的特征提取方法,机器学习的分类方法,虹膜图像的质量评价,不完整、不合作情况下的虹膜识别以及活体虹膜检测。     

基于扩展单粒子模型的锂离子电池参数识别策略

为了精确识别电动汽车锂离子动力电池的关键状态参数,基于多孔电极理论和浓度理论,建立了一种考虑液相动力学行为的锂离子电池扩展单粒子模型.相较于传统单粒子模型,该模型增加了对负电极表面固体电解质界面膜参数的描述,并考虑了温度和液相浓度变化对锂离子电池关键参数的耦合影响.基于所建立的扩展单粒子模型,提出一种简化的参数灵敏度分析方法和有效的锂电池参数识别策略,用以确定特定工况下的高灵敏度待识别参数,进而利用遗传算法实现参数的优化求解.最后,通过对比分析本文模型和传统单粒子模型的仿真输出电压和相同工况下电池的实验输出电压验证了提出模型和参数识别方法的有效性和可行性,为电池管理系统的健康状态估计提供了理论基础.     

不确定自催化反应扩散时空混沌系统的延时同步

设计了一种延迟同步控制器实现了时空混沌系统之间的同步控制.基于Lyapunov稳定性定理,确定了延迟同步控制器的结构以及系统状态变量之间的误差方程.以自催化反应扩散时空混沌系统为例,仿真模拟验证了该控制器的有效性.进一步设计了参量辨识器,对不确定自催化反应扩散时空混沌系统中的参量进行了有效辨识.通过研究有界噪声影响下系统的同步效果,表明该同步方法具有较好的抗干扰能力. 关键词： 时空混沌 延时同步 参量辨识 有界噪声     

GeⅩⅩ～GeⅩⅩⅥ谱线的测量和辨认

测量了线聚焦激光加热锗等离子体发射的ＸＵＶ光谱，对ＧｅＸＸ～ＧｅＸＸⅥ谱线进行了辨认和分类。给出了谱线波长和相对强度；计算了辐射跃迁几率和吸收振子强度；并与其它实验室有关结果进行了比较。     

Tb0.3Dy0.7Fe2合金的本构参数辨识方法研究

建立了一种简便的、适用于磁畴模型应用的Tb0.3Dy0.7Fe2合金本构参数辨识方法.针对Tb0.3Dy0.7Fe2合金磁畴模型中本构参数不明确且直接实验测试困难的问题,提出了一种数值计算与实验测试相结合的参数辨识方法.采用坐标变换与绘制自由能等势曲线相结合的方法,简化了载荷作用下Tb0.3Dy0.7Fe2合金内磁畴角度偏转的数值计算,研究了合金磁畴角度偏转模型的参数依赖性.在此基础上,结合简单的实验测试,建立了Tb0.3Dy0.7Fe2合金各向异性常数K1和K2、能量分布因子ω、晶轴取向分布的辨识及修正方法.该方法能够简单、快速地完成Tb0.3Dy0.7Fe2合金磁畴模型中本构参数的辨识,对完善磁致伸缩材料磁畴偏转的数值计算模型非常有意义.理论分析可为类磁致伸缩材料磁机耦合模型的建立、完善,以及材料本构参数的辨识、获取提供参考.     

三维荧光光谱结合Tchebichef矩快速鉴别掺伪芝麻油

应用FS920荧光光谱仪测定样品的三维荧光光谱数据,直接利用Tchebichef矩提取三维光谱灰度图的特征信息,然后对其进行聚类分析,最后通过逐步回归建立样本中各成分的线性模型。聚类分析能够准确识别掺伪芝麻油,并正确解析其组成成分,得到的线性模型相关系数R>0.99。研究表明,Tchebichef矩能够有效提取光谱的特征信息,应用于掺伪芝麻油鉴别可获得良好的定性和定量分析结果。