浅谈磨机滚动轴承支承结构设计及轴承配合选择

磨机使用滑动轴承的优点是顺应性、嵌藏性好，抗胶合能力强，缺点是传动时摩擦阻力大，磨机功耗高。同时，频繁刮瓦费时繁琐，而且影响磨机运转率，维护费用高，在磨机上使用滚动     

FreeRTOS内存管理方案的分析与改进

针对FreeRTOS内存管理方案分配时间不确定,切割次数较多,利用率低及合并机制不足等缺点,采用一种“精确切割”和“延时合并”相结合的策略以最大限度减少内存碎片,提高内存利用率。具体实现方法是在FreeRTOS中引入TLSF（Two-level Segregated Fit）算法数据结构,采用二级位图索引对动态内存进行管理,并改进TLSF算法的内存分配和释放过程;最后将改进的算法以及FreeRTOS移植到STM32开发平台上进行实验测试。测试结果表明该方法提高了FreeRTOS的内存分配速度,减少了内存碎片率。     

基于回波趋向伪本征极化特性的目标识别研究

本文在全极化、高距离分辨力雷达体制背景下,研究了光学区雷达目标回波趋向一征极化的特性的并利用指数函数族拟合的方法对其进行了定量描述,在此基础上对四类军用飞机目标进行了识别实验研究,获得了良好的目标分类识别效果。     

数控加工技术中的一种双圆弧新插补方法

本文提出了数控加工技术中双圆弧插补的一种新方法：公切点选取不是从几何出发而是从最省材料的物理角度来考虑，并直接首次给出了满足工程设计要求的计算公式而无需迭代，还首次给出了工程设计点的概念。     

基于UG的装配特征自动识别及其逆向参数化方法研究

在三维CAD系统中,不论是自下而上还是自上而下的设计模式,对于组成装配体的不同零件之间仅能实现一对一的尺寸参数关联.提出了一种基于UG装配体装配特征自动识别的方法,分析了装配特征的各种定义和表达方法,建立了基于配合尺寸链的相关零件的尺寸关联,实现了逆向参数化设计,并在UG NX3.0环境开发了一个实现该功能的独立模块.     

机油泵零件配合公差的探讨与选用

内燃机机油泵的可靠性是难以保证而又必须保证的重要指标。本文从配合公差选用角度来探讨其对可靠性的影响。     

Outsourcing capabilities,organizational structure and performance quality monitoring: Toward a fit model

Provider IT services has grown substantially, since the advent of IT. However, research on it has been limited and mainly qualitative. A recurring provider problem was identified: a lack of attention to the performance of the IT they provide. Due to uncertainty or change in the client environment, the fit between capabilities and organizational structure of outsourcing providers must be balanced. Here we present the results of an exploratory quantitative empirical study among outsourcing experts involved with three different types of IT outsourcing providers: domestic, offshore, and global.     

Effect of wearing jeans on the back muscle flexion-relaxation phenomenon

The flexion–relaxation phenomenon (FRP) in back muscles is related to the lower back load. Although the FRP has been widely discussed, the effect of wearing jeans—a common attire in workplaces—on the FRP is unexplored. This study recruited 20 male participants with high and low flexibilities (10 each) and measured the related muscle activity and lumbopelvic movement at five trunk flexion angles (0°–90°) when wearing two types of bottom wears (swim trunks and fit jeans). Results revealed that the bottom wear type and trunk angle significantly affected all responses, whereas flexibility affected only erector spinae and hamstring activities. Participants with high flexibility and wearing swim trunks exhibited greater erector spinae activity than did those with low flexibility and wearing jeans. Thus, those who have low flexibility or are wearing jeans are likely to experience more activity reductions in erector spinae. However, the result with hamstring activity was the opposite. Wearing jeans limited participants’ pelvic rotation, forcing them to bend their lumbar spine further to complete trunk flexion, thus reducing erector spinae activity. A looser attire should be chosen to avoid constraining the pelvic rotation when work involves a deep trunk flexion.Relevance to industryPeople wearing jeans have limited pelvic movement and decreased erector spinae activity during deep trunk flexion, and this may further strain their interspinous ligaments. Thus, people should not wear fit jeans when in workplaces where their work involves stooping or trunk flexion exceeding 45° to minimize the load on their lower back.     

衔铁组件精密压装技术及设备

为实现衔铁组件过盈联接的高精度压装作业,研制了一套基于压力传感器、光栅尺、机器视觉的精密压装设备。该设备的移动横梁通过直线轴承与导向轴配合,在直线推杆的作用下沿导向轴移动,完成压装作业。根据导向轴和轴承的相关尺寸和公差,计算了压装过程中的导向偏差,并且在考虑压头压装面平行度和衔铁内孔垂直度的情况下,分析了压装设备抑制偏摆的能力。通过对光栅尺进行标定,保证了压装位移的准确测量。随机抽取10套零件进行压装实验,结果表明衔铁压装平行度≤±0.008mm、衔铁压装高度<±0.01mm、反馈杆压装高度≤±0.01mm。上述实验结果说明压装设备满足使用要求。     

复合轨道梁加工方法的研究

现在加工件越来越复杂，尤其是各种新型轨道梁的出现．它们体积庞大、重量多在1MN以上，传统的装夹已经根本无法适应。本文提出基于CAD模型和机床测量复合轨道梁的姿态匹配定位计算方法，利用最小二乘法计算转换矩阵，实现非定位加工，在工程应用中取得良好效果．尤其是在上海磁悬浮列车轨道梁加工中达到了预期效果，保证工程的顺利进行．