太极拳运动考评软件的设计与实现

针对太极拳教学现状,基于自主学习理论,提出设计基于关键帧提取技术和三维坐标变换技术的太极拳运动考评系统。本文采用运动捕捉技术采集了24式太极运动数据,以关键帧提取技术为基础,设计了运动时间对比模块,解决了运动速度对比问题;以三维坐标平移变换和朝向旋转变换技术为基础,设计了运动空间对比模块,解决了运动位置对比问题;结合运动速度对比与运动位置对比,系统能够自动地对教学运动素材进行对比与评价,满足了学生自主学习需求。     

一种基于和差波束的机载 SAR 定位方法

机载 SAR 绝对定位技术可以直接对地面目标进行定位,无需地面参考点,对于军事及民事应用具有重要的实用价值.该文提出一种新的机载 SAR 对地定位方法,主要研究在无地面参考点的情况下,利用和差波束 SAR图像直接对地面目标定位,获取地面目标3维坐标信息.论文分析了载机速度、高度及测角误差对定位精度的影响,并与传统基于距离多普勒模型的定位方法进行了比较,最后通过仿真实验验证了该定位方法的有效性.     

三维表面扫描机器人系统本体标定新方法

提高三维表面扫描机器人系统的机器人本体定位精度是其用于制造加工质量控制的关键,提出一种基于三坐标测量机和非线性优化方法的机器人本体标定方法。该方法首先设计并加工一个测量转接件,测量转接件由3个标准球组成,将其安装于机器人的末端,利用三坐标测量机获得转接件上精确的球心坐标,并且通过串口获得机器人的6个关节角度值。而后建立机器人运动学本体标定的目标函数,确定所要优化参数的初值后,通过Levenberg-Marquardt优化方法得到机器人的实际D-H参数。将获得的实际D-H参数应用于修正后的机器人运动学模型,由未参与计算的验证点数据表明标定后的机器人绝对定位精度提高了一倍。     

Effect of plane strain on microstructures and texture, through the reduction ratio of AZ31 Mg alloy

Structural evolution of warm-rolled AZ31 alloy sheets was investigated with respect to various reduction ratios. In order to examine the effect of rolling pass on deformation of the sheet, one-pass rolling was applied to the AZ31 alloys for various 6/1/2011reduction ratios. When the applied reduction ratio was ∼85% of the initial thickness, significant grain refinement and texture development were achieved with dynamic recrystallization. Moreover, with the increase of the rolling reduction ratio from 30% to 85%, the warm rolled sheets exhibit plane strain mode displaying uniform 〈0 0 0 1〉//ND basal textures throughout the whole sheet thickness. The two-dimensional finite element method simulation showed that the current lubrication rolling results in a uniform plane strain deformation through the whole warm rolled sheet.     

Numerical simulation of TBM construction ventilation in a long diversion tunnel

A three-dimensional Renormalization-group (RNG) k-ε model has been performed for forced ventilation to the working face of a long diversion tunnel, taking into account the effects of air leakage and the frictional resistance along the tunnel. The case study involves the working face during TBM construction of the Xinjiang 81 Daban long diversion tunnel, China. Analysis of the flow-field distribution and the pressure distribution near the working face and tunnel outlet revealed the relationships among the air leakage rate per 100 m, pressure difference at the air leakage port, and quantity of air in the air duct. The simulation results show that the air flux, velocity, and leakage rate gradually decrease along the tunnel. The air leakage rate per 100 m increases logarithmically along with pressure growth when the latter is limited within a certain pressure difference range. A low-pressure area can be found on the duct wall near the air leakage port, and the pressure inside the tunnel gradually decreases from the working face to the tunnel outlet; the velocity is relatively high near the leakage port, and is low in the tunnel. The simulated results were in good agreement with the experimental work by Cigdem Aydin and Hui-min Wang, and the simulated axial velocities of the tunnel were validated with the empirical value.     

铁路移动定测系统的设计与实现

基于VRS、SerialPort通信、Socket通信、GPS坐标变换、NMEA0183协议等关键技术,本文利用Windows Mobile 5.0 SDK平台以及.Net Compact Framework 2.0类库,在Visual studio 2005（C#语言）开发环境中开发了PDA铁路移动定测软件。试验结果...     

Enhanced rate capability of nanostructured three-dimensional graphene/Ni3S2 composite for supercapacitor electrode

Three-dimensional graphene/Ni₃S₂ (3DG/Ni₃S₂) composite electrodes were produced by a facile two-step synthesis route involving chemical vapor deposition (CVD) growth of graphene foam and in situ hydrothermal synthesis of Ni₃S₂. The porous structure of the prepared 3DG is ideal for use as a scaffold for fabricating monolithic composite electrodes. The relative content of Ni₃S₂ initially increased and then decreased with increasing hydrothermal reaction time. The basal surface of the electrode was completely covered after 6 h of hydrothermal reaction. The size of the Ni₃S₂ microspheres also increased with increasing hydrothermal reaction time. The composite electrodes exhibited good specific capacitance (11.529 F cm⁻² at 2 mA cm⁻², i.e., 2611.9 F g⁻¹ at 5 mV s⁻¹) and cyclability (retention of 88.97% capacitance after 1000 charge/discharge cycles at 20 mA cm⁻²). These results are attributed to the fact that the uniform distribution of the Ni₃S₂ microspheres increased the specific surface area of the electrode and facilitated electron transfer and ion diffusion. The 3D multiplexed and highly conductive pathways provided by the defect-free graphene foam also ensured rapid charge transfer and conduction to improve the rate capability of the supercapacitors.     

苏里格气田低产低效井差异化管理对策

鄂尔多斯盆地苏里格气田储层非均质性强,气水分布规律复杂,随着开发的深入,低产低效井增多,气井的管理、资料分析和应用难度加大。为此,结合对该气田储层地质认识、生产动态特征分析和现场试验的成果,提出"苏中控压稳产、苏西控水开发"的技术思路,将苏中气井分为高、中、低产井;苏西气井分为连续带液井、间歇带液井和积液井,分类分析评价气井生产动态,并提出各类气井的开发技术政策。在气井分类管理的基础上,形成了具有该气田特色的低产低效井差异化管理对策:①不断优化低产井间歇生产制度,有效减少和降低储层应力敏感效应和水锁伤害,提高了低产井外围储量动用程度;②建立气井"三维矩阵"管理方式,明确了气井措施适用范围,量化了措施实施参数,提高了气井措施有效率;③应用智能化气井管理平台,推行气井全生命周期管理。差异化管理对策贯穿气井整个生命周期,大大提高了气井管理效率,老井的开井时率、新井贡献率、措施有效率明显上升,为该气田稳产提供了帮助和支持,也为同类气田的高效开发提供了技术支撑。     

阿姆河盆地查尔朱阶地中部低幅构造天然气藏研究

通过对研究区地层、沉积相、油气丰度、油气地质特征的综合研究及对已有油气藏的解剖,建立了低幅构造天然气藏形成的地质模式并指出了油气勘探有利区带。低幅构造发现的关键是通过优化地震参数设计、野外采集参数优选和室内保真处理。本文在地质模型指导下,采用井-震联合标定技术,对地震资料进行了精细解释,发现和准确的描述了多个盐下低幅度构造,通过对其中2个圈闭的钻探,均获得了高产天然气流,发现了具底水、层状低幅西莎天然气田,同时,首次在下侏罗统砂岩发现了重要油气显示,展现了低幅度构造在查尔朱阶地勘探的重要意义。