直线度误差目标函数凸凹性的研究

证明了直线度误差最小区域评定法的目标函数是一维欧式空间R1中的连续、不可微的凸函数 ,从而证明了目标函数的全局极小值是唯一的。     

Ionospheric response to the 17 March and 22 June 2015 geomagnetic storms over Wuhan region using GNSS-based tomographic technique

By using the data of GNSS (Global Navigation Satellite System) observation from Crustal Movement Observation Network of China (CMONOC), ionospheric electron density (IED) distributions reconstructed by using computerized ionospheric tomography (CIT) technique are used to investigate the ionospheric storm effects over Wuhan region during 17 March and 22 June 2015 geomagnetic storm periods. F-region critical frequency (foF2) at Wuhan ionosonde station shows an obvious decrease during recovery phase of the St. Patrick’s Day geomagnetic storm. Moreover, tomographic results present that the decrease in electron density begins at 12:00 UT on 17 March during the storm main phase. Also, foF2 shows a long-lasting negative storm effect during the recovery phase of the 22 June 2015 geomagnetic storm. Electron density chromatography presents the evident decrease during the storm day in accordance with the ionosonde observation. These ionospheric negative storm effects are probably associated with changes of chemical composition, PPEF and DDEF from high latitudes.     

浅析工业建筑未来发展趋势

根据我国基本国情及目前建筑业的发展水平，借鉴国外工业建筑成功经验，工业建筑的发展就节约用地的原则而言，宜向多层、高层方向发展；就人与环境协调发展考虑，宜向民用建筑化方向发展；就职业安全与卫生方面，宜向高水平高标准方向发展。     

无热化大相对孔径星敏感器光学系统设计

提出了一种大相时孔径轻小型光学系统的设计方案,给出了设计方案及热分析结果.光学系统工作谱段500～800nm,视场角9°,相对孔径1／1.2,光学系统设计结果良好,弥散斑直径在两个像元尺寸之内,能够满足光学系统对能量集中度和弥散斑的要求.基于光学热补偿理论对光学系统进行了无热化分析和消热设计.通过分析不同温度下的传递函...     

大量程力平衡加速度表的系数标定技术

对比研究了用于加速度表标定的重力场，离心机与电模拟的三种方法，给出了在国内目前没有大ｇ值精密离心机条件下，如何解决大量程加速度表的系数标定问题。     

大型复杂构件制造过程残余应力演化与调控

归纳了残余应力的基本类型及各类残余应力的计算机仿真方法，概述了残余应力形成与演化行为及残余应力调控技术的研究现状。以机械臂基座本体淬火过程为例，展示了有限元仿真在大型复杂构件残余应力演化行为分析上的应用；以工字型材模压去应力为例，通过有限元仿真重现了变截面构件模压去应力的过程并分析了模压去应力的影响因素。讨论了残余应力仿真预测与调控技术应用于组件及其涵盖构件制造-服役全寿命周期的可行性，预测了其集成于智能制造技术体系的巨大潜力。     

Two dimensional simulation of amplitude modulated electron plasma waves

Highly modulated waves near electron plasma frequency with both parallel and perpendicular polarization have been observed near diffusion region at dayside and in the tail region. In this paper, two dimensional Particle-In-Cell (PIC) simulation was performed to study the possible generation mechanism of these modulated electron plasma waves. It is shown that weak beam instability could generate the modulated Langmuir wave and the ambient magnetic field plays an important role in the formation of modulation. When the weak beam has loss cone distribution, highly modulated upper hybrid waves are generated and propagate with large angle to the ambient magnetic field. The properties of these modulated waves are discussed and compared with observations.     

数控布带缠绕机关键技术

 多功能数控布带缠绕机是集机械、电子、气动、控制、软件和数控等技术一体化的多学科交叉综合应用的复杂设备。从提高参数控制精度及匹配精度的角度出发,详细地介绍了一种新型布带缠绕机的结构、组成及实现方式,并对机床本体、张力控制系统、温度控制系统、压力控制系统及数控系统的设计与开发中的关键技术做了较为深入的探讨。将该技术应用于多功能布带缠绕设备中,采用专用数控系统、先进机械装置及控制算法,既实现了缠绕成型过程的自动化,又保证了缠绕制品的质量,解决了复合材料零部件成型过程的关键制造技术难题。     

基于CAD模型的涡轮叶片误差检测系统

涡轮叶片型面误差检测是其制造过程中的重要环节.研究了涡轮叶片型面误差检测关键技术的实现方法,提出了基于测量数据的叶片截面关键参数的自动提取方法以及测量数据与计算机辅助设计(CAD)模型的坐标配准方法,制定了衡量叶片截面轮廓度、倾斜度、弯曲度和扭曲度的评估指标,并基于UG平台开发了叶片型面误差检测系统.应用实例表明,该系统可显著提高叶片的误差检测速度和分析质量.