网络RTK在数字化测图一级控制网布设中的应用

近几年来,GPS-RTK技术在数字化地形图测绘中已得到广泛应用。结合杭州富阳市1∶500数字化地形图测绘工程实例,探讨了在数字化地形图测绘中运用网络RTK进行一级控制网布设的方法、原理和可行性,并对测绘结果进行了精度分析。通过实验验证:用网络RTK施测的一级控制点方法的精度完全符合《浙江省GPS-RTK测量技术规定》的要求,此成果完全可以满足测区的1∶500数字化地形图测图需要。     

RTK测量高程精度探讨

通过RTK技术在海阳市城区控制测量中应用,分析了校正参数的求取方法及影响参数精度的因素;从观测精度、基准转换参数精度和基准站控制点精度三方面入手,阐述了提高RTK高程的具体措施;并通过对高程精度和高差精度两方面进行分析,得出RTK高程测量的精度能够达到四等水准测量精度要求的结论。     

RTK技术在沈阳市区图根控制测量中的应用

文中主要叙述了RTK技术在沈阳市图根控制测量中的应用，通过比较说明RTK的测量精度完全能够满足1：500地形测图图根控制的精度要求．     

城市地籍测量1：500航测成图精度

本文介绍了地籍测量作业中利用1∶3000像片测绘1∶500图的精度,统计资料表明物点点位中误差为±0.173米。     

IKONOS卫星影像在若羌河山区河段1∶10000地形图测制中的应用

详细介绍IKONOS卫星立体影像在新疆若羌河山区河段1∶10 000地形图测制中的应用,并以项目资料为基础,对不同像控点数量及分布情况的定向精度进行分析,给出同类项目控制点布设方案的建议。     

云南首次大面积利用低空无人机进行航摄及1∶2000 DOM的制作

论述了利用低空无人机航摄系统在云南省首次进行大面积高分辨率航摄,并成功制作5 000余km2、0.2 m分辩率的1∶2 000正射影像图(DOM)的主要技术流程,并对最终获得的DOM的精度进行分析,旨在为利用低空无人机航摄系统进行大面积高分辨率航摄,以及制作1∶2 000正射影像图提供一些参考。     

基于卫星影像的多尺度DLG更新技术研究

文中以资源三号卫星影像立体像对为数据源,按照1:10 000和1:50 000 DLG成图要求对地物要素进行更新,并且结合检测数据对成果精度统计分析。试验表明资源三号卫星立体像对可以满足部分地形1∶10 000地形图成图的精度要求,提高了1∶10 000地形图更新的工作效率。     

无人机航测技术在土遗址保护工程中的应用

文章在详细介绍无人机航测外业、内业作业方法的基础上,分析了大疆M300 RTK在郑州某遗址工程施工中的应用及其测量精度。结果表明,在现场环境条件较好及一定的像控点密度下,无人机航测计算得到的检查点点位精度能达到1∶500地形图的精度要求,且与传统测量手段相比,土方量计算的相对中误差也达到了0.12%,说明无人机航测作业手段可为类似的土遗址保护工作提供参考。     

双基站RTK布设控制点精度分析

实时动态测量技术(简称RTK)已广泛应用于图根控制测量,施工放样测量及地形碎部测量等诸多方面。但相对于GPS静态测量,单基站RKT布设控制点缺少必要的检核条件,文中通过分析RTK技术特点及工程实例,得出RTK控制测量精度指标,结果证明双基站RTK布设控制点精度数据稳定,完全满足施工放样控制测量要求。     

无人机在矿区1∶2000地形测绘中的应用研究

以无人机航摄技术在矿区1∶2 000大比例尺地形图测绘中的应用为研究目的,采用复合翼无人机搭载非量测相机,对甘肃某矿区进行了地形图快速测绘与更新,生产了该矿区1∶2 000地形图和矿区的正射影像图。通过外业施测像控点对测图高程精度的检测与分析,结果表明:通过提前布设地标点,严控飞行质量等误差影响因素,此无人机可满足矿区1∶2 000航测成图。     

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     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。