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基于加速度量测幅值零速检测的计步算法研究
Step Counting Algorithm Based on Zero Velocity Update
 [PDF]

陈国良, 杨洲
CHEN Guoliang
, YANG Zhou

- , 2017, DOI: 10.13203/j.whugis20150400
Abstract: 准确的步数统计是进行人员航位推算的关键,通过分析行人运动模型及步行姿态,设计了一种基于零速检测的加速度量测幅值计步算法,实现了载体坐标系和行人地理坐标系的转换,剔除了伪零速现象,在室内模拟环境下采用低成本的微机电机械系统(micro electro mechanical system,MEMS)惯性测量元件对人员行走进行检测,实现了行人运动姿态的有效识别和步数的精确统计。实验结果表明,该计步方法准确性高,对不同的运动环境(走廊、拐角和楼梯)具有良好的适应性,计步正确率均达到98%以上,并且所用的测量元件功耗低,便于携带,适合室内复杂环境
横风下普速客车与动车组在挡风墙后交会气动性能
Aerodynamic performances of common passenger train and EMU passing by each other under crosswind and wind-break wall
 [PDF]

周志鹏, ,姚松,刘凯,梁玉
ZHOU Zhipeng
, , YAO Song, LIU Kai, LIANG Yu

- , 2018,
Abstract: 基于三维、非定常、不可压缩N-S方程和k-ε双方程湍流模型,采用滑移网格技术,对横风作用下普速客车与动车组在挡风墙后交会气动性能进行数值模拟,并研究4种挡风墙高度对交会列车气动性能的影响。研究结果表明:数值模拟的列车表面瞬变压力与实车试验结果规律一致,交会压力波峰值的相对误差在10%以内;普速客车和动车组在横风下交会时,横风使得列车头部和尾部最大正压区和负压区域均发生了横向偏移;动车组与普速客车所受横向力和倾覆力矩均随着车速的增加而增加,当普速客车车速由100 km/h增至160 km/h时,普速客车和动车组倾覆力矩峰值分别增加了11.7%和20.8%,动车组受交会车速的影响更大。设置3.5 m高的挡风墙时,列车受到的横向力在4种挡风墙高度中整体上最小,与无挡风墙时相比,普速客车机车和动车组头车受到的横向力峰值分别下降了85.7%和45.4%,列车气动性能明显改善。
On the basis of the three-dimensional unsteady incompressible N-S equation and the turbulence model of k-ε two equations, the sliding mesh method was adopted, and the aerodynamic performances of EMU passing by common passenger train under crosswind and wind-break walls were simulated. The results show that by contrasting the transient pressure on the train surface with numerical simulation is consistent with the results of full-scale experiment, the peak values of pressure wave shows agreeable accordance with the error under 10%. When trains passing by each other under crosswind, the crosswind makes the pressure zone of train had lateral movement. The lateral force and overturning moment increase with the increase of train speed, and when the speed of common passenger train increase from 100 km/h to 160 km/h, the peak values of overturning moment of common passenger train and EMU increase by 11.7% and 20.8%. When 3.5 m wind-break walls are set in line side, the lateral force of trains almost approach the minimum value in the four heights, and the lateral force acting on head car of common passenger train and EMU decrease by 85.7% and 45.4% compared with no wind-break wall, which means the aerodynamic performances of the two trains are obviously improved
太行山猕猴第Ⅶ颈椎变量的异速生长分析  [PDF]
薛德明
动物学杂志 , 2001,
Abstract: 以肱骨最大长为参照,对成年太行山猕猴第Ⅶ颈椎变量进行了异速生长分析。结果表明,椎体后高、椎体上矢径、全宽呈正异速生长;椎体下横径接近等速生长;椎体前高、椎体下矢径、椎体上横径、椎孔矢径、椎孔横径、矢径呈负异速生长。
镀膜锰铜计的压阻性能研究  [PDF]
施尚春,张清福,罗教明,程菊鑫,陈攀森
高压物理学报 , 1992, DOI: 10.11858/gywlxb.1992.01.010
Abstract: 用磁控阴极等离子体溅射技术在云母基底上制作镀膜锰铜压阻计。5~56GPa冲击应力的标定实验表明,该计的压阻性能稳定。压阻系数的拟合式为p(GPa)=-0.14+90.63(ΔR/R0)+10.81(ΔR/R0)2-7.64(ΔR/R0)3,式中R0为锰铜计初始电阻,ΔR为受压时的电阻变化值。
一种测量中等压力的新方法——双压阻计法  [PDF]
黄正平,冯喜春
兵工学报 , 1991,
Abstract: ?本文介绍一种适用子测量中等压力的双锰铜压阻计测压方法。此法把H型或双π型等低阻值锰钢压阻计的量程扩展到O,2Gpa,压力的最高分辨率达到20MPa。
阵列式薄膜锰铜计的动态压阻响应研究  [PDF]
滕林,杨邦朝,杜晓松,周鸿仁,崔红玲
高压物理学报 , 2004, DOI: 10.11858/gywlxb.2004.03.014
Abstract: 利用直流磁控溅射薄膜工艺制备阵列式薄膜锰铜压阻计,以氧化铝作为基片和绝缘封装材料。在结构上,4个具有相同阻值的薄膜锰铜计在同一氧化铝基片上呈对称分布。51.72GPa压力下的动态加载实验表明,4个计的压阻一致性好,无高压旁路效应,验证了薄膜锰铜压阻计动态测试的准确性和可靠性。
降雨影响散射计测风的初步研究  [PDF]
杨吉龙,张雪虎,陈秀万,柯樱海,daniel,esteban,james,carswell,david,jmclaughlin,paul,chang,peter,black,frank,marks
遥感技术与研究 , 2005,
Abstract: 给出了降雨影响c、ku波段微波散射计测量海面风速的初步结果。研究结果显示,海面风速为25~30m/s时,雨速为15mm/hr的降雨会使这两个波段的微波散射计测量的风速偏低10m/s。  
冲击波中横向、纵向应力计响应初步研究  [PDF]
段卓平,关智勇
高压物理学报 , 2002, DOI: 10.11858/gywlxb.2002.04.005
Abstract: 采用低阻值锰铜压阻应力计,通过一维平板撞击实验和理论分析对横向、纵向应力计在有机玻璃和陶瓷材料中的不同响应进行了研究。实验结果表明,在陶瓷等硬质材料中进行横向应力测量时,可用康铜计补偿的方法,直接用锰铜计纵向标定的压阻系数计算,而在有机玻璃中却不能简单地得到横向应力。
小水线面双体船横摇阻尼特性数值与试验研究  [PDF]
孙小帅, 姚朝帮, 叶青
SUN Xiaoshuai
, YAO Chaobang, YE Qing

- , 2017, DOI: 10.11887/j.cn.201706012
Abstract: 针对安装稳定鳍的小水线面双体船开展了零速静水自由横摇衰减数值与试验研究。通过不确定度分析验证数值计算方法的可靠性,进而对比船体的线性横摇阻尼和非线性横摇阻尼,并分析摩擦阻尼和稳定鳍对小水线面双体船横摇恢复力矩的影响规律。结果表明:由数值计算求得的自由横摇衰减曲线与试验结果吻合良好;在线性横摇运动假设下,线性横摇阻尼系数随着初始横倾角的增加而增大;将通过数值计算求得的非线性阻尼系数代入到非线性横摇运动方程中能准确地模拟船体的自由横摇衰减运动;摩擦阻尼和稳定鳍对小水线面双体船零速静水自由横摇时的横摇恢复力矩贡献很小。
A SWATH (small waterplane area twin hull) installed with stabilizing fins rolling freely in calm water was investigated by both numerical approach and experimental method. Uncertainty analysis was made to verify and validate the numerical method. Both linear roll damping and nonlinear roll damping were obtained and the contributions of the frictional damping and the stabilizing fins to the roll restoring moment were analyzed. The results illustrate that: the numerical free roll decay curve agrees well with the experiment; under the assumption of linear roll mode, the linear roll damping coefficient sees an upward trend with the increase of initial heel angle; the computed free roll decay curves using nonlinear damping coefficients agree well with the experimental results; the frictional damping and the stabilizing fins make minimal contributions to the roll restoring moment for the free roll decay motion in still water.
流体横掠方形微针肋阵列热沉的传热特性  [PDF]
夏国栋,李宴君,孔凡金
工程热物理学报 , 2008,
Abstract: 本文以去离子水为冷却工质,对流体横向冲刷方形微针肋阵列热沉的传热特性进行了实验研究.结果表明流体横掠微针肋热沉具有优越的换热特性。实验得出,冷却液的雷诺数对热沉的换热性能影响显著;总热阻随着泵功的增大而降低;对流换热热阻在总热阻中所占比例较小,流体吸热焓变热阻成为影响热沉性能的主导因素.
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