共查询到20条相似文献,搜索用时 46 毫秒
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陈玉祥 《水力采煤与管道运输》1994,(1)
煤炭部煤矿专用设备标委会1993年秘书长工作会议简报煤矿专用设备标委会水采机械分会简讯第七期煤炭部煤矿专用设备标委会1993年秘书长工作会议,于1993年11月30日至12月3日在北京召开。参加这次会议的有煤炭部科教司.部技术监督处、煤科总院和总院技... 相似文献
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煤矿机械中液压冲击的机理分析与控制方法 总被引:1,自引:0,他引:1
目前煤矿机械中普遍采用液压传动技术,而液压冲击是煤矿机械液压系统和元件的常见故障之一,它不仅影响液压元件的使用寿命,而且严重妨碍系统的正常工作。分析了液压冲击的产生机理,根据能量守恒定律建立了冲击压力的数学计算模型,并针对产生液压冲击的回路和元件提出了控制策略。 相似文献
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<正> 由煤科院太原分院和中国矿业大学共同研制的煤矿液压支架用DYF型大流量安全阔于1988年5月通过了部级鉴定。该阀的研制对延长液压支架的使用寿命、减轻支架重量、确保采煤工作面安全生产及提高综采工作面经济效益都有着极为重要的意义。DYF型大流量安全阀是煤矿液压支架承受动载荷时的过载保护元件,其主要技术 相似文献
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煤矿专用设备标委会电气分会第二次年会召开煤炭部煤矿专用设备标准备化技术委员会电气设备分会第二次年会于1993年11月10日至14日在浙江省建德市召开。参加会议的代表有:总会秘书处、分会委员、通讯成员及特邀嘉宾共44人。电气分会副主任委员王瑞义向大会作... 相似文献
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阐述了煤矿机械设备维修用液压压力机(用废旧液压元件和材料制造)设计的主要内容,简要说明了其结构特点,并分析了液压系统的性能。 相似文献
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<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 相似文献
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《中国稀土信息(英文版)》2014,(6)
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 相似文献
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YANG Li 《中国稀土信息(英文版)》2014,(6)
<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 相似文献
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Gao Wei 《中国稀土信息(英文版)》2014,(11)
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 相似文献
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《中国稀土信息(英文版)》2014,(8)
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 相似文献
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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。 相似文献
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Chen Zhanheng 《中国稀土信息(英文版)》2014,(5)
<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 相似文献
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Bai Wenping 《中国稀土信息(英文版)》2014,(12)
<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 相似文献
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《中国稀土信息(英文版)》2014,(9)
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 相似文献
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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。 相似文献