基于创新能力培养的仪器分析实验教学改革与实践

针对仪器分析实验课程的教学现状,以提升学生综合学术素养为导向,以培养化学学科拔尖人才为目标,提出将分析仪器组装和拆装废旧分析仪器等创新实验教学方式引入到仪器分析实验教学当中。以这些创新实验教学为例详细阐述了这些创新实验内容。在教学过程中,将讨论式教学、演示实验和线下实际操作相结合,并辅以口头报告、专题讨论等多种教学手段,在丰富课程教学元素的同时充分也充分调动了学生的学习兴趣,取得了很好的教学效果。同时,结合课程特点,依据分析仪器实验的特色及适用领域对创新实验进行教学设计,挖掘课程思政元素,进行课程与思政融合的教学探索与实践。

BNES对转子系统扭转振动抑制的理论和试验研究

为了抑制转子系统的扭转振动,提出了一种双稳态非线性能量阱(bi-stable nonlinear energy sink,BNES).首先介绍了BNES的结构和工作原理,在此基础上建立了转子-BNES耦合系统的动力学方程.然后利用数值计算方法,对BNES在瞬态和稳态激励下的振动抑制能力进行了研究,并与相同转动惯量的线性动力吸振器(linear dynamic vibration absorber,LDVA)进行了对比.最后,搭建测试平台,试验验证了BNES对转子系统扭转振动抑制的能力.研究结果表明,该BNES对转子系统的瞬态响应以及稳态响应具有良好的振动抑制效果;在给定的参数下,BNES的振动抑制能力优于LDVA.

GNES和LDVA在转子系统振动抑制中的性能比较

为了抑制各向异性转子系统的横向振动,设计了一种接地式非线性能量阱(grounded nonlinear energy sink,GNES)和一种线性吸振器(linear dynamic vibration absorber,LDVA).首先介绍了GNES的结构、工作原理及一些固有特性;然后分别建立GNES和LDVA与转子系统组成的耦合系统的动力学模型;最后,采用数值法分析了两种吸振装置的抑振效果.结果表明,在给定参数下,GNES的抑振性能优于LDVA.

基于MatDEM的烟家沟滑坡演化过程数值模拟分析

在对陕西省山阳县烟家沟滑坡基本地质特征调查的基础上,利用无人机获取滑坡高程数据,基于高性能矩阵离散元软件MatDEM建立起烟家沟滑坡运动及堆积特征的三维离散元模型,还原了滑坡启动发生的全过程,最终得到了运动速度、滑移距离以及堆积体厚度3个方面特征,取得以下认识:烟家沟滑坡属于高速滑坡;滑坡运动堆积过程分为加速碰撞堆积阶段、整体滑动堆积阶段和减速堆积阶段;其堆积层厚度分布沿运动方向呈现出先增加后减小的总体变化趋势,且堆积厚度在堆积体后部达到最大;MatDEM矩阵离散元法用来模拟滑坡演化过程具有可行性.

非光滑NES在转子-叶片系统振动抑制中的应用

用非光滑非线性能量阱(non-smooth nonlinear energy sink,NSNES)抑制转子-叶片系统的振动,NSNES结构采用分段线性刚度梁形式.首先介绍了NSNES的结构和工作原理,然后利用拉格朗日方程建立转子-叶片-NSNES系统的动力学模型,最后采用数值法分析了该耦合系统处于稳态共振时,NSNES对转子振动和叶片振动的抑制能力.在给定参数下,附加于叶片尖部的NSNES在抑制转子振动时,抑振率可达到68%;在抑制叶片振动时,抑振率可达到62%.文中还将该NSNES的抑振能力与具有相同质量线性动力吸振器(linear dynamic vibration absorber,LDVA)的抑振能力进行了对比.

Landslide susceptibility assessment using the certainty factor and analytic hierarchy process

A new approach combining the certainty factor(CF) and analytic hierarchy process(AHP) methods was proposed to assess landslide susceptibility in the Ziyang district, which is situated in the Qin-Ba Mountain region, China. Landslide inventory data were collected based on field investigations and remote sensing interpretations. A total of 791 landslides were identified. A total of 633 landslides were randomly selected from this data setas the training set, and the remaining landslides were used for validation as the test set. Nine factors, including the slope angle, slope aspect, slope curvature, lithology, distance to faults, distance to streams, precipitation, road network intensity degree and land use were chosen as the landslide causal factors for further susceptibility assessment. The weight of each factor and its subclass were calculated by AHP and CF methods. Landslide susceptibility was compared between the bivariate statistical method and the proposed CF-AHP method. The results indicate that the distance to streams, distance to faults and lithology are the most dominant causal factors associated with landslides. The susceptibility zonation was categorized into five classes of landslide susceptibility, i.e., very high, high, moderate, low and very low level. Lastly, the relative operating characteristics(ROC) curve was used to validate the accuracy of the new approach, and the result showed a satisfactory prediction rate of 78.3%, compared to 69.2% obtained with the landslide susceptibility index method. The results indicate that the CF-AHP combined method is more appropriate for assessing the landslide susceptibility in this area.

异步起动永磁同步电机设计关键技术发展综述

异步起动永磁同步电机相比于异步感应电机,具有体积小、重量轻、效率高和功率因数高等优点,在水泵、风机等领域具有广泛的应用前景。异步起动永磁同步电机设计流程包括定子和绕组设计、转子鼠笼设计、永磁体设计、计算稳态性能指标分析四个步骤。针对国内外异步起动永磁同步电机研究工作,侧重从转子拓扑结构设计和性能优化方面进行了综述,认为异步起动永磁同步电机未来研究应着眼于应生态化优化设计、结构设计、热问题设计和专业化应用四个方向。

Determination of Cd,Pb and Sr by Microwave Plasma Torch Atomic Emision Spectrometry Using an Electrothermal Vaporization Sample Introduction System

A method for the determination of Cd,Pb and Sr by microwave plasma torch(MPT)atomic emission spectrometry(AES)was developed.Th e samples were introduced into the MPT with an elec trothermal vaporization(ETV)device.The effects of some experimental conditions on the de-termination of Cd,Pb and Sr were examined.The effects of easily ionized elements on the emis-sion intensity of Cd,Pb and Sr were studied in detail.The detection limits for Cd,Pb and Sr are 2.4,4.0 and 1.3 ng/mL,respectively.

朝阳市2015年-2017年无偿献血者血液不合格原因分析

目的探究朝阳市无偿献血者血液不合格原因及预防策略。方法对朝阳市2015年-2017年所有无偿献血者血液标本,利用酶联免疫吸附试验(ELISA)及速率法进行乙肝表面抗原(HBs Ag)、丙型肝炎病毒抗体(anti-HCV)、人免疫缺陷病毒抗体(anti-HIV)及梅毒螺旋体抗体(anti-TP)和谷丙转氨酶(ALT)检测。结果在83 539份血液标本中有1 329份为不合格血液标本,五项检测项目中以ALT的不合格率最高,为0. 71%;其次为anti-TP,不合格率为0. 34%。结论朝阳市2015年-2017年无偿献血者血液ALT和anti-TP不合格成为血液报废主要原因,严格执行采血前征询和初筛工作,规范操作,保障输血的安全性,提高血液标本合格率,以减少对血液资源的浪费,使更多献血者的血液得到合理利用。