灰色模型(GM)在软土路基沉降量预测中的应用研究

该文讨论了灰色系统理论在软土路基沉降量预测中的应用 ,以京珠高速公路灵山试验段沉降观测数据为例 ,建立了沉降量灰色预测模型 ,并与三点法、双曲线法的预测结果以及实测结果进行了对比 ,结果表明 ,灰色预测模型的预测沉降量与实际沉降量更接近。最后分析了用灰色模型进行预测应注意的问题     

老采空区残余沉降的离散灰色预测模型

针对老采空区残余沉降序列波动性较大、传统灰色模型预测效果差的不足,建立了残余沉降的多变量离散灰色预测模型(DGM(2,2)),取阶次为2以适应残余沉降的波动变化,选择残余沉降值作为沉陷系统的主行为因子,而将空气、地下水等外界渐变因素对沉陷系统的综合影响作为相关因子,并按等时间影响原则进行量化。通过实例将DGM(2,2)模型的预测结果与6种传统灰色预测模型作对比分析。结果表明:DGM(2,2)预测模型在拟合优度、预测精度和稳定性等方面明显优于传统灰色预测模型,且建模过程避免了微分方程的解算,降低了计算复杂度。     

基于灰色系统模型的矿区地表沉降预测研究

文中以灰色Verhulst模型为预测模型,以陕西北部某煤矿某综采工作面地表26期实测沉降值为实验数据,开展了地下采矿后地表沉降预测的实践研究。以实验数据中的A10、A11、A12和A13号监测点预测结果计算了灰色系统模型检验中后验方差法的C值和P值,进行了预测模型的精度评价。结果表明:灰色系统Verhulst模型精度达到了一级,可为地下采煤区地表沉降预测研究与实践提供参考。     

灰色系统预测在基坑信息化施工中的应用

基坑工程系统是一个灰色系统。根据灰色系统理论，建立了基坑变形的GM（1，1）预测模型。根据工程实例的位移及沉降观测值对后续施工中的变形值进行预测，并用工程实例后续监测值加以验证。研究结果表明，基坑变形的灰色预测模型具有较好的精度，对指导基坑开挖和支护具有积极意义。     

灰色Verhulst模型在白象山铁矿地表沉降趋势预测中的应用

地表沉降曲线与灰色Verhulst预测模型为特征一致的"S"形曲线,利用灰色Verhulst预测模型理论,以矿山疏干过程中的地表沉降实测数据为样本,计算矿山的模型参数,构建了矿山的灰色Verhulst预测模型。经过模型预测矿山地面沉降高峰期发生在5～7 a,最大沉降速率为7.6 cm/a,且10 a之后基本趋于稳定。     

灰色模型预测城市地面沉降的研究

文中简要介绍了灰色系统理论,针对西安市单个水准点的一组高程时间序列观测数据,建立了灰色预报GM(1,1)模型,预测西安市某点近期沉降量。计算结果表明,预测模型计算结果与实测值拟合较好。同时,用VB编制了灰色模型预测程序,证明其正确性和有效性,并绘制了其高程沉降图。     

基于不等时距模型的烟囱基础沉降预测

为了克服灰色模型以上以等时距原始数据作为前提条件的缺点,对灰色模型进行了改进,建立了不等时距的预测模型,将不等时距灰色模型应用于某烟囱基础沉降预测中。通过沉降预测与实际监测值对比表明,不等时距灰色预测模型精度较好,可以运用到实际工程中。     

两种预测模型在客专路基沉降预测中的对比分析

在提出客运专线路基沉降预测重要性的基础上,以灰色预测模型GM(1,1)和双曲线模型,对路基沉降变形观测数据进行了分析预测,并结合实例,编写matlab程序,对这两种预测结果做了对比分析.结果分析显示:灰色预测模型GM(1,1)比双曲线模型在客运专线路基沉降预测具有更高的精度,效果更佳.     

基于不等时距模型的烟囱基础沉降预测

为了克服灰色模型以上以等时距原始数据作为前提条件的缺点,对灰色模型进行了改进,建立了不等时距的预测模型,将不等时距灰色模型应用于某烟囱基础沉降预测中.通过沉降预测与实际监测值对比表明,不等时距灰色预测模型精度较好,可以运用到实际工程中.     

钻孔扩底灌注桩沉降量的灰色预测

利用实测的钻孔扩底灌注桩静载试验数据,用灰色系统理论建立桩基沉降量的灰色GM(1,1)预测模型,并用残差GM(1,1)模型对原预测值进行修正。研究结果表明,建立的GM(1,1)模型可有效预测桩基沉降量。应用实例中,用预测的桩基沉降量修正了其实测值,结果表明,钻孔扩底灌注桩具有比检测结果更优的承栽性能。     

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。