无需顾及初值的坐标转换法拟合任意方向点云圆柱面

文中提出了一种简便可行的方法来拟合点云圆柱面,其主要通过改进坐标转换法的圆度误差方程进行去相关变换来减弱方程对初值的依赖性,因此不必顾及参数初值的选取。进一步对不同组点云数据的拟合结果进行分析,并在投影坐标系下绘制圆度投影图和等值线,验证了该方法的准确性和实用性。     

基于平板典型零件的多孔圆度与圆柱度误差测量系统设计

设计了一种测量平板典型零件多孔圆度与圆柱度误差的测量系统。选取了系统的测量方法,并进行了数学建模,分析了测量系统的工作原理。对测量系统的误差进行了分析,并对测量系统的数值进行了计算,结果表征:测量系统性能和精度满足要求,提高了多孔平板零件孔的圆度、圆柱度误差测量效率,对同类零件的检测提供借鉴和参考。     

两种圆柱体拟合算法的研究

圆柱拟合是工业测量中的常见问题,文中比较了基于坐标转换和基于点到直线位置关系的两种圆柱拟合算法的拟合原理和解算过程。通过实测数据表明,两种算法均能得到极佳的拟合精度,但基于坐标转换的拟合算法收敛速度更快,求解效率更高。     

单配圆柱斜齿轮的测绘方法

圆柱斜齿轮的测绘，难点就在测绘其分度圆螺旋角，介绍了用公法线长度来计算其法向模数。再用公法线长度及齿顶圆直径互推法来估算变位系数及分度圆螺旋角，然后用滚齿机校验分度圆螺旋角，从而算出准确的参数，测绘的精确度都能满足单配的要求。     

基于K折交叉验证的SVM隧道围岩分级判别

针对隧道施工期间围岩分级因样本数较少存在分类结果可靠性较低的问题,建立基于K折交叉验证的支持向量机判别模型。依据TSP303系统确定判别指标并建立判别指标体系; 根据围岩勘测情况,将围岩分为4个等级,并作为输出变量; 选取40组样本数据训练模型、10组样本数据测试模型,结果表明,10组样本中仅1组样品判别错误,准确率达到90%。研究成果为隧道围岩的分级判别提供了新方法。     

基于机器人技术的液压油缸圆度测量

提出一种基于机器人技术的液压油缸内圆圆度测量方法,以便携式大变径油缸机器人为载体,利用激光传感器进行圆度测量,实现了大变径油缸的圆度测量。建立了机构圆度检测数学模型,利用转台和激光传感器配合进行数据采集。进行了算法仿真分析以及油缸圆度测量实验,分别使用了S-G平滑滤波法和均匀窗平滑滤波法2种方法进行数据处理。经验证该方法具有良好的检测性能,可实现精度为0.03 mm的测量,适用于液压油缸内壁圆度检测。     

基于PCA-Bayes综合判别的矿井突水水源判别研究

根据矿井各含水层水化学成分的差异性,选取多种水化学成分指标作为突水水源识别的样本变量,综合利用多元统计分析技术、Bayes逐步判别法和PCA-Bayes综合判别法作比较,采用SPSS软件建立Bayes逐步判别模型、PCA-Bayes综合判别模型,以煤矿不同含水层的水化学资料中的多组样本为依据,利用该模型进行工程应用。结果表明：PCA-Bayes综合判别模型提高了突水水源判别的准确率和判别速度,实现了对矿井突水水源快速有效判别,为防治突水事故提供了有力的依据和判别方法。     

薄壁深孔零件高精度夹具的研制

薄壁深孔零件,在加工时容易产生变形和制造误差,导致加工精度难以保证,通过对夹具的合理改造,设计了一种针对薄壁深孔加工的专用夹具,改善了使用三爪卡盘夹持在加工中的圆度、圆柱度的高精度很难保证的问题,在实际的加工中,具有广泛的推广价值。     

GPS高程拟合方法的适用性研究

为研究各种GPS高程拟合方法所适用的不同范围,分别采用多项式拟合法、多面函数法、解析内插法对GPS测量点的高程进行拟合。针对地形起伏较大地区的高程点,计算出大地高和正常高之间高程异常的拟合残差,通过对各种方法计算的拟合残差的比对,探寻各种高程拟合所适用的条件。得出的结果表明:对于文中数据所反映的地形特点和数据点的布设方式,采用多面函数法具有较高的拟合精度、多面函数法拟合的平均误差较多项式拟合法减少37.5%,较解析内插法减少57.1%左右。不同的拟合方法有各自的特点以及适用范围和条件,对同一组数据采用不同的方法拟合,结果存在着很大的差异。     

某山前工业场地边坡稳定性分析研究

在论述某山前工业场地边坡地段工程地质条件的基础上,重点阐明边坡岩体结构特征及其有关物理力学指标,采用赤平极射投影法确定边坡中危险分离岩体边界条件,并分别采用赤平极射投影摩擦圆图解法和块体极限平衡法对其稳定性进行分析和计算,对拟建山前岩质边坡稳定性作出了评价.     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared