用剪切波速判别土液化

通过野外试验得到了粒状土的剪切波速与标贯阻力之间的符合实际的相关关系。这一关系同以前的研究也相吻合，同时还获得了粒状土的剪切波速与圆锥静阻力之间的类似的相关关系。利用西特提出的标准贯入试验土液化图，提出以剪切波速为基础的可用于各震级的土流化判别图。     

天津软土剪切波速影响因素的灰色关联分析

剪切波速是评价场地土动力特性的重要指标。很多地区基于已有勘察资料 ,取得了剪切波速与深度及土性指标之间的统计关系。但影响剪切波速的诸多因素的主次关系难以确定 ,致使在工程中难以找出影响剪切波速的主要因素 ,从而难以确定具有代表性的统计关系。该文引入灰色系统中灰色关联理论 ,对天津地区剪切波速及相应土性指标进行了灰色关联分析 ,得到了该地区影响剪切波速因素的主次关系。     

豫东平原土层剪切波速与埋深关系分析

对豫东平原郑州市、开封市、新乡市、濮阳市、商丘市、周口市市区部分钻孔土层剪切波速测试数据进行了整理。采用线性函数方程、幂函数方程和一元二次函数方程建立了各市土层剪切波速与埋深之间的回归公式,采用拟合优度指标对回归分析结果进行评价。结果表明:郑州市、新乡市、濮阳市、商丘市的拟合优度比较高,达到0.90以上;而开封市、周口市的拟合优度比较低。以拟合优度作为评价指标,初步建立了各市土层剪切波速与埋深关系函数表达式。     

山东东营城区剪切波速回归分析及应用

剪切波速是当前工程场地地震安全性评价和地震小区划工作中必备的参数之一,是土层地震反应分析中一个重要参数.然而受到实际情况的制约,测试不能达到工作要求的深度或是测试结果未满足要求,这时必须对剪切波速进行估计.该文通过对东营城区46个钻孔土体剪切波速测试结果的统计回归分析,提出了线性函数、幂函数相结合的土体剪切波速推算公式...     

用标准贯入试验方法时锤击数的取值问题

闽南地区花岗岩强风化界面的确定 ,在采用标准贯入试验作定量评价时 ,锤击数N是否修正 ,不同规范定义不一。该文以剪切波速成果为参照标准 ,结合经验鉴别 ,对工程实测资料进行剖析 ,最终认为N值应修正     

基于规范法的机场大面积填挖地基液化等级判别与处理深度讨论

该文采用规范法进行液化地基的液化指数计算及液化等级判定,并考虑机场进行大面积填挖方引起地势设计标高变化的工况,对规范公式进行修正并计算,讨论了基于标贯试验的液化指数计算的起算标高.通过对采用标贯击数计算液化指数标贯临界值以及液化指数的公式进行深度修正,求取其与填挖方深度的函数关系,并引用北京某机场液化地基标贯实测数据进行验证对比,结论为该修正方式与增加上覆非液化土层厚度可减小液化指数及等级的震后调查结论矛盾,应采用天然地面标高进行计算.液化地基处理措施及深度的控制采用规范初步判别标准,上覆非液化土层厚度考虑了填挖方引起的增减.对液化地基处理方式及深度不做要求,仅对处理后的效果采用标贯试验进行验证,并采用初步判别标准作为处理效果的评价标准.     

土样现场和室内剪切波速的试验研究

利用安装在动三轴仪上的剪切波速测试装置 ,测试了天津某地区土的剪切波速 ,并在此基础上将室内测试结果与现场测试值进行了比较。研究发现二者的差值与土层埋深、粘粒含量等因素有直接关系     

泉州市区场地土层剪切波速特征

根据实际观测资料研究了泉州市区场地土层刚度（剪切波速）的特征。对实测的泉州市区场地土层剪切波速进行数理统计，研究了泉州市区场地各主要土层剪切波速的数理统计特征和场地土等效剪切波速的分布规律。从对泉州市区场地土等效剪切波速的分布特征与场地土覆盖层厚度的分布规律的分析，得出场地土等效剪切波速与场地土覆盖层厚度密切相关。最后，应用研究成果对泉州市区场地进行初步土动力学的评价，为泉州市区建筑物的抗震设防及场地选择提供参考依据。     

淠河砂层的液化判别

本文综述了按标贯击数、液化势指数、等效剪应力、最大应力比和剪切波速五种液化判别的方法,并结合实际工程对诸法判别结果进行了讨论。     

砂土密实度的划分

本文介绍全国各地70多份砂土地基上载荷试验与静探、标贯的对比试验结果,采用P～S关系曲线与太沙基得出的沉降图,建立图解密度的分析方法,提出①用静探比贯入阻力值P_s来划分砂土的密度.②用标准贯入试验锤击数N=6,N=13来作为松散与稍密,稍密与中密的二个界限值.并对江苏太仓县邻近地区砂土密度按各种划分标准进行分析研究.     

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     

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     

2014 second batch of rare earth quota released

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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