非稳态导热乘积法测量煤体热物性的不确定度分析

为解决现有技术在测试多孔介质材料的热物性参数时由于加热热源存在热阻值或对被测试样加热不均匀从而导致测试结果精度不高的问题,在基于无量纲温度场乘积法的思路下采用非稳态导热乘积法测松散煤体的热物性参数,再根据测试系统采集的实验数据分布并结合GUM (测量不确定度表示与指南)中标准不确定度的A类和B类不确定度分析、合成标准不确定度及扩展不确定度该4种不确定度,对松散煤的热扩散率测试系统进行不确定度分析。研究表明:煤样热扩散率的合成不确定度值为1%,其扩展不确定值为2.01%,各种煤样热物性的测量结果与相关文献的相对偏差在5%以内,最大相对偏差为4.09%。由此验证了该测试方法的稳定性和可行性,有效拓展了松散煤体的热物性测量方法,并避免加热热源存在热阻损耗及对被测试样加热不均匀性等问题。     

参数估计在松散煤体热物性测试中的应用

基于模拟退火算法,提出考虑接触热阻的松散煤体热物性参数估计方法。首先介绍考虑接触热阻影响的传热数学模型,针对由于参数灵敏度系数线性相关,而无法同时估计接触热阻和试样热扩散率的情况,提出先估计热扩散率再估计接触热阻。然后在自行研发的松散煤体热物性测试系统上进行实验测试,参数估计与实验测试结果相符很好(相对误差2%),仿真计算结果也表明本参数估计方法是可行的。针对研究结果,相同实验条件下,接触热阻随煤样粒径的增加先增加后减小,但不超过6.6681×10-4(m2·K/W),不考虑接触热阻引起的热物性参数测试误差≤3%。     

松散煤体导热系数测定系统设计

提出利用平面热源法测定松散煤体导热系数,在数学模型中考虑了松散煤体导热系数与温度的依变关系,详细介绍了数学模型的求解过程,并在此基础上设计了松散煤体导热系数测定系统。该系统也可用于其他类似材料的热物性测定。     

煤层不同地质结构相似材料配比实验研究

为研究煤岩层与隐蔽地质异常体地球物理响应特征,本文基于矿井工作面煤岩层结构设计,构建煤岩隐蔽致灾异常体实体1:1大型物理模型进行模拟实验.采用煤粉、砂石、水泥等材料通过正交试验方法对新元矿的煤层、顶底板、陷落柱和断层等进行相似材料配比与制作工艺实验以及物性参数实验测试,并将获得的波速、电阻率、介电常数等物性参数实验数据...     

电绝缘导热材料的热物性研究

本文报道了两种电绝缘导热材料BeO和BN导温系数的测试结果,并对其进行了误差分析;找出它们的导温系数随温度变化的规律,为BeO和BN在防爆壳内作为电绝缘导热材料的应用,提供了热物性依据。     

测井参数曲线在地层物性研判中的应用

测井获得的参数曲线,在某些地层段出现与地层地质物性不相符的曲线形态特征.通过分析地层物性特征及研判依据,列举了不同地球物理测井参数曲线的分析方法,结合具体实例中地层岩性所具有的物理性质,综合判断了钻孔剖面裂隙、破碎带、空洞,并以井中电视测井的方法进行了验证.钻孔裂隙发育、岩体破碎后,体积松散,孔隙增大,渗透性增强、液压...     

散装乳化炸药水相材料物性分析

结合散装乳化炸药水相材料物性实际数据, 用ASPEN PLUS软件对水相材料在不同温度下进行了pure和binary物性分析, 结果表明, 物性分析数据与实际数据相符。     

松散承压含水层下采煤突水机理与防治研究

针对祁东煤矿多起采煤工作面突水灾害问题,采用现场测试和模拟实验方法,对松散承压含水层下采煤顶板导水裂隙发育特征与突水机理、突水危险区域预测与突水灾害防治对策等进行了深入研究.结果表明:祁东煤矿采煤工作面每次突水前都伴随有压架现象,说明工作面突水灾害的发生与覆岩破断运动紧密相关.由于松散承压含水层的载荷传递作用,易导致覆岩关键层产生复合破断,引起松散承压含水层下部较大范围岩层的整体破断,使得顶板导水裂隙发育高度异常增大而沟通含水层,这是引发松散承压含水层下采煤发生异常突水灾害的根本原因.提出了松散承压含水层下采煤突水危险区域的预测方法和突水灾害防治对策,指导了祁东煤矿松散承压含水层下采煤突水灾害的防治实践.     

跳汰机水动力因素的测定和床层松散度的研究

<正> 跳汰机是在垂直脉动流中选别物料的常用重选设备,其分选效果与水流的脉动特性和床层松散过程有直接关系。因此,考查水流脉动特性、床层松散状况与分层效果间的关系,是跳汰机生产操作和理论研究工作的主要内容。长期以来,由于测试技术条件的限制,     

三峡库区松散地质体加固声波测试法试验研究

对三峡库区奉节、巫山等地的松散地质体灌浆加固试验,应用室内岩块声波测试、现场钻孔声波测试及跨孔测试等方法可获得松散岩土体的地球物理动力学参数,用以评价库区松散地质体的灌浆加固效果,并定量评价三峡库区的松散岩土体的稳定性。     

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。