基于双无迹卡尔曼滤波算法的永磁同步电机转子磁链辨识

转子磁链的准确辨识是实现永磁同步电机(Permanent Magnet Synchronous Motor, PMSM)转子磁场监控,确保其驱动系统可靠运行并实现高性能控制的有效方法。为解决测量噪声、电机参数变化及辨识模型欠秩对转子磁链辨识精度影响的问题,提出了基于双无迹卡尔曼滤波（UKF）算法的PMSM转子磁链辨识方法,可在确保满秩辨识的前提下,减小测量噪声与电机参数变化对转子磁链辨识精度的影响,实现PMSM转子磁链的准确辨识,并在参数敏感性分析的基础上,降低了算法计算量,合理兼顾了辨识精度与辨识速度。对所提方法进行了仿真研究和实验验证,研究结果证实了所提方法的有效性。     

气相色谱-三重四极杆质谱联用测定沉积物中的多氯联苯

建立索氏提取-气相色谱三重四极杆质谱多反应监测同时测定沉积物中19种多氯联苯单体的方法,确定19种多氯联苯化合物多反应监测模式(MRM)的最佳质谱条件。方法检出限为0.020～0.025μg/kg,以不含目标物的沉积物作为空白基体,加入19种不同浓度水平的多氯联苯作回收试验,测得回收率为82%～111%,测定的相对标准偏差均小于7.3%。     

磨刀门水道枯季底边界层的泥沙交换过程

河口底边界层细颗粒泥沙运动往往受边界层内多种尺度的动力过程影响而变得十分复杂。由此,基于座底支架上的ADV与OBS,于2010年枯季在珠江磨刀门水道分别进行大、中、小潮的底边界层观测,对磨刀门水道底边界层湍流动力特征与小尺度泥沙交换过程进行研究。结果表明:悬沙有效沉速、床面切应力与底床侵蚀率的变化范围随着潮差的增大而增大;底床侵蚀率与平均流速变化规律相似,当流速小于0.3 m/s时,侵蚀率基本保持在0.002 kg/m2左右,流速超过此临界值时,床面泥沙发生再悬浮。悬沙和床沙交换过程随着潮差增大而增强,且落潮时段强于涨潮时段。     

The Influence of the Air-Drying Pretreatment of Sediment Samples for Metallic Element Mobilities

Chemical analysis of sediments provides an efficient tool for water quality management. Ten sediment samples collected in 2008 from two locations situated in the Danube Delta Biosphere were analyzed in a comparative study of mobile metallic elements via two different pre-treatment techniques: air-drying followed by sieving and wet sieving. The experimental data proved that air-drying procedure produces drastic changes in mobility of the metallic elements from the sediments which were studied as an effect of the oxidizing conditions. Wet sediment or oxygen-free dried sediment is recommended to be used in environmental studies regarding determination of mobile fractions from sediment samples.     

A monotone finite volume scheme for advection–diffusion equations on distorted meshes

A new monotone finite volume method with second‐order accuracy is presented for the steady‐state advection–diffusion equation. The method uses a nonlinear approximation for both diffusive and advective fluxes that guarantee the positivity of the numerical solution. The approximation of the diffusive flux is based on nonlinear two‐point approximation, and the approximation of the advective flux is based on the second‐order upwind method with proper slope limiter. The second‐order convergence rate for concentration and the monotonicity of the nonlinear finite volume method are verified with numerical experiments. Copyright © 2011 John Wiley & Sons, Ltd.     

考虑主、漏磁路饱和影响的异步电机数学模型

本文用综合矢量法推导出考虑主，漏磁路饱和影响下异步电机的通用数学模型．用此模型计算一台笼式异步电动机的起动瞬态过程计算与试验结果吻合较好．     

微机在电子式电动阀流量控制中的应用

在水工模型中，应用电子式电动阀控制流量时，由于电子式电动阀对微机控制信号的响应比较慢，导致流量超调，严重地影响了物理模型的稳定性，针对流量控制中的这一问题，从微机控制电子式电动阀的特点出发，给出了电子式电动阀的优化控制算法，并从软件上予以实现，试验证明，优化的控制算法使流量控制稳定可靠，提高了物理模型试验的精确度。     

北部湾东侧沉积物硫酸盐还原菌含量及其意义

用ＭＰＮ法测定了北部湾东侧沉积物硫酸盐还原菌含量,表层沉积物ＳＲＢ的检出率约７６．３％。浅层中是３１．３％。表层和浅层中各自的ＳＲＢ平均含量分别是１７６０．０个每克和３４４．４个每克。     

Progress in the applications of flux analysis of metabolic networks

The metabolic network has become a hot topic in the area of system biology and flux-based analysis plays a very important role in understanding the characteristics of organism metabolic networks. We review mainly the static methods for analyzing metabolic networks such as flux balance analysis (FBA), minimization of metabolic adjustment (MOMA), regulatory on / off minimization (ROOM), and dynamic flux balance analysis with linear quadratic regulator (DFBA-LQR). Then several kinds of commonly used software for flux analysis are introduced briefly and compared with each other. Finally, we highlight the applications of metabolic network flux analysis, especially its usage combined with other biological characteristics and its usage for drug design. The idea of combining the analysis of metabolic networks and other biochemical data has been gradually promoted and used in several aspects such as the combination of metabolic flux and the regulation of gene expression, the influence of protein evolution caused by metabolic flux, the relationship between metabolic flux and the topological characteristics, the optimization of metabolic engineering. More comprehensive and accurate properties of metabolic networks will be obtained by integrating metabolic flux analysis, network topological characteristics and dynamic modeling.     

湖盆滩坝沉积研究进展

 介绍了滩坝的定义,综述了湖盆滩坝研究的相关成果。滩坝可根据其沉积物、发育位置以及对与潮汐作用响应等进行分类。基于沉积物,滩坝分为碳酸盐岩滩坝和碎屑岩滩坝;基于发育位置,滩坝分为近岸滩坝和远岸滩坝等;基于对潮汐作用响应,滩坝分为小潮差滩坝、中潮差滩坝和大潮差滩坝等。针对滩坝砂体沉积特征提出滩坝的沉积模式,并可进一步对其内部微相进行划分。滩坝发育的控制要素为古地貌、水动力条件、沉积旋回、物源以及古水深、古气候等,古地貌的控制体现在岸线形态和局部地形起伏;水动力条件的控制体现在不同强度的波浪作用;沉积旋回的控制体现在基准面的升降和旋回;物源的富集及贫乏对滩坝的形成类型起到决定性作用;古水深、古气候则影响滩坝的发育与否。