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EXPLICIT ERROR ESTIMATE FOR THE NONCONFORMING WILSON'S ELEMENT 被引量:3
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作者 赵纪坤 陈绍春 《Acta Mathematica Scientia》 SCIE CSCD 2013年第3期839-846,共8页
In this article, we study the explicit expressions of the constants in the error estimate of the nonconforming finite element method. We explicitly obtain the approximation error estimate and the consistency error est... In this article, we study the explicit expressions of the constants in the error estimate of the nonconforming finite element method. We explicitly obtain the approximation error estimate and the consistency error estimate for the Wilson's element without the regular assumption, respectively, which implies the final finite element error estimate. Such explicit a priori error estimates can be used as computable error bounds. 展开更多
关键词 Nonconforming finite element explicit error estimate Wilson's element
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Non Degeneration of Fibonacci Series, Pascal’s Elements and Hex Series
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作者 Balasubramani Prema Rangasamy 《Advances in Pure Mathematics》 2020年第7期393-404,共12页
Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I ex... Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I explored the inter relations of Fibonacci series when I was intent on Fibonacci series in my difference parallelogram. In which, I found there is no degeneration on Fibonacci series. In my thought, Pascal triangle seemed like a lower triangular matrix, so I tried to find the inverse for that. In inverse form, there is no change against original form of Pascal elements matrix. One day I played with ring magnets, which forms hexagonal shapes. Number of rings which forms Hexagonal shape gives Hex series. In this paper, I give the general formula for generating various types of Fibonacci series and its non-degeneration, how Pascal elements maintain its identities and which shapes formed by hex numbers by difference and matrices. 展开更多
关键词 Fibonacci series Lucas series Golden Ratio Various Type of Fibonacci series Generated by Matrices Matrix Operations on Pascal’s elements and Hex Numbers
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基于D-S证据理论的岩爆预测方法研究
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作者 高永涛 朱强 +1 位作者 吴顺川 王勇兵 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第2期244-251,共8页
为了有效预测岩爆,提出基于D-S证据理论的岩爆预测方法.首先,选取与岩爆发生相关的6个指标因素作为证据体,并通过模糊物元框架和正态型隶属度函数构建证据体的基本概率分配.然后,利用K均值将证据体分类,并提出簇内证据用传统方式融合而... 为了有效预测岩爆,提出基于D-S证据理论的岩爆预测方法.首先,选取与岩爆发生相关的6个指标因素作为证据体,并通过模糊物元框架和正态型隶属度函数构建证据体的基本概率分配.然后,利用K均值将证据体分类,并提出簇内证据用传统方式融合而簇间证据用权重方式融合的组合融合规则,以减轻高冲突证据融合的不利影响.最后,将模型应用在秦岭终南山公路隧道2号竖井工程,且与经验方法对比.为了分析预测过程的不确定性和估计岩爆发生概率,采用蒙特卡洛模拟进行抽样仿真,并通过Spearman秩相关系数衡量输入指标的全局敏感性.研究结果表明:输入指标在不同的岩爆案例的影响程度差异较大且方向不同;5个岩爆案例的发生概率在40.8%~70.1%之间.该模型表现出优异的预测分类性能,可为深埋地下工程岩爆预测提供参考. 展开更多
关键词 岩石力学 岩爆预测 D-s证据理论 模糊物元 K均值
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小红石砬子铅锌(银)矿床成因:来自S-Pb同位素和元素特征的证据
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作者 王贵龙 王达 +2 位作者 白峰 徐德兵 王高天 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第1期241-266,共26页
小红石砬子铅锌(银)矿床是吉中-延边铜镍多金属成矿带中具有代表性的中型矿床,前人关于该矿床类型划分的观点有火山成因块状硫化物型(Volcanogenic Massive Sulfide,VMS)、中-低温热液脉型、喷流沉积-热液叠加改造型,这三种观点的争论... 小红石砬子铅锌(银)矿床是吉中-延边铜镍多金属成矿带中具有代表性的中型矿床,前人关于该矿床类型划分的观点有火山成因块状硫化物型(Volcanogenic Massive Sulfide,VMS)、中-低温热液脉型、喷流沉积-热液叠加改造型,这三种观点的争论严重制约了对该矿区及区域成矿和找矿的认识。本文选取该矿床中金属硫化物开展原位微量和S-Pb同位素分析,赋矿围岩开展全岩S同位素分析。闪锌矿Fe-Zn含量(4.48%~10.33%、53.67%~62.12%)与中温热液矿床一致(3.00%~10.00%、50.00%~60.00%,成矿温度约200℃),Zn/Cd比值(53.68~76.75)同样指示中低温成矿作用(高温:Zn/Cd>500;低温:Zn/Cd<250),Ga/Ge比值在lg(Ga/Ge)-T图解中,对应温度约为100~180℃,上述温度范围与前人测定的流体包裹体均一温度基本吻合(90~250℃)。闪锌矿Zn/Cd的比值(53.68~76.75)与Cd含量(7577×10-6~11266×10-6)特征与密西西比河谷型(Mississippi Valley-Type,MVT)矿床一致;黄铁矿Fe/S比值(0.76~1.29,平均值为0.89)接近典型MVT矿床的理论值(0.88)。金属硫化物δ34 S V-CDT值介于-9.6‰~-0.5‰之间,总体偏负;赋矿围岩δ34 S V-CDT值介于-8.5‰~4.2‰之间,两者重叠范围较大(主要集中于-9.0‰~-2.0‰),说明围岩提供了主要的还原硫,而古老基底可能提供了部分较轻的硫。金属硫化物Pb同位素比值为206 Pb/204 Pb=18.30~18.39、207 Pb/204 Pb=15.61~15.63、208 Pb/204 Pb=38.38~38.44,指示铅为混合来源,成矿物质可能主要来自上地壳和造山带,模式年龄计算显示上太古界乌拉山群变质岩可能为铅的初始来源。综上所述,小红石砬子铅锌(银)矿床地球化学特征与MVT型矿床基本一致,地质特征略有差别,因此推测其为类MVT型矿床。 展开更多
关键词 小红石砬子矿床 s-Pb同位素 元素分析 矿床成因 类MVT矿床
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S对铸造高温合金K417G凝固行为的影响
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作者 杨亚倩 邢炜伟 +1 位作者 丁磊磊 马颖澈 《特殊钢》 2024年第2期30-38,共9页
在1340~1230℃采用等温凝固实验,研究了w[S]分别为0.0001%、0.0018%和0.0037%对K417G合金凝固特性的影响。结果表明,S降低合金的固相线温度,扩大固液两相区,当w[S]从0.0001%增加到0.0037%时,合金的固相线温度由1255℃降低至1245℃。在... 在1340~1230℃采用等温凝固实验,研究了w[S]分别为0.0001%、0.0018%和0.0037%对K417G合金凝固特性的影响。结果表明,S降低合金的固相线温度,扩大固液两相区,当w[S]从0.0001%增加到0.0037%时,合金的固相线温度由1255℃降低至1245℃。在凝固过程中S元素偏析于液相,并在终凝区析出Y相,且S促进Al、Cr元素在固液界面处的富集。在相同等温温度下,S元素对MC碳化物和γ+γ’共晶的析出温度与形貌无明显影响,但S含量的增加促使MC碳化物、γ+γ’共晶和Y相数量的增加,且Y相的析出温度从1230℃提升至1240℃。 展开更多
关键词 s 等温凝固 K417G 元素偏析 Y相
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ESD保护电路在HDMI板级信号完整性中的影响分析及其布局优化研究
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作者 王淼 李嘉豪 +1 位作者 汤浩 郭亚 《现代电子技术》 北大核心 2024年第8期68-74,共7页
为了解决HDMI接入ESD保护电路后信号完整性受破坏等问题,从器件的空间布局对HDMI信号完整性影响进行研究分析,同时考虑了瞬态电压抑制(TVS)高频寄生参数的影响,搭建了ESD放电模型和TVS高频等效电路模型,并对其可靠性进行了验证。从差分... 为了解决HDMI接入ESD保护电路后信号完整性受破坏等问题,从器件的空间布局对HDMI信号完整性影响进行研究分析,同时考虑了瞬态电压抑制(TVS)高频寄生参数的影响,搭建了ESD放电模型和TVS高频等效电路模型,并对其可靠性进行了验证。从差分器件接入信号线旋转角度和彼此间错开距离研究其对信号完整性的影响,设计了25套不同夹角和4套不同错开距离的板级模型,在不同特性的传输频率下进行S参数仿真,并从中选取出垂直型、水平型、错开型三种具有代表性的空间布局模型,利用有限元仿真得到差分信号线的S参数和眼图。仿真结果表明,垂直型排布相比于其他两种典型空间布局,回波损耗平均降低了248.1%,插入损耗平均降低了20.6%,眼图的眼宽和眼高在三种空间布局中最大。研究成果为PCB静电放电保护电路分析与设计提供了布局优化指导。 展开更多
关键词 静电放电(EsD) HDMI 信号完整性 空间布局优化 瞬态电压抑制(TVs) s参数 有限元仿真
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基于S-A模型的覆冰输电线绕流数值分析 被引量:1
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作者 廖绍凯 张研 陈达 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2023年第1期110-117,共8页
基于Spalart-Allmaras湍流模型(S-A模型)封闭的雷诺平均N-S方程,采用沿均匀流线的三阶Runge-Kutta法和Galerkin法分别进行时间和空间离散,得到了湍流方程的有限元格式。采用自编Matlab程序,数值模拟了不同风攻角下覆冰输电线绕流问题,... 基于Spalart-Allmaras湍流模型(S-A模型)封闭的雷诺平均N-S方程,采用沿均匀流线的三阶Runge-Kutta法和Galerkin法分别进行时间和空间离散,得到了湍流方程的有限元格式。采用自编Matlab程序,数值模拟了不同风攻角下覆冰输电线绕流问题,得到了覆冰输电线绕流瞬态和时均流场、气动力系数时程曲线和平均气动力系数随风攻角的变化关系,并与试验结果进行对比,验证了该算法的有效性。基于流场演化和平均压力分布,分析表明风攻角变化引起的边界层分离点转移是产生升力系数尖峰突跳现象的主要原因。 展开更多
关键词 spalart-Allmaras模型 雷诺平均N-s方程 RUNGE-KUTTA法 有限元格式 覆冰输电线 流场演化 气动力系数
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Analysis of the geometrical dependence of auxetic behavior in reentrant structures by finite elements 被引量:5
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作者 V.H.Carneiro H.Puga J.Meireles 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第2期295-300,共6页
Materials with a negative Poisson's ratio(PR)are called auxetics;they are characterized by expansion/contraction when tensioned/compressed.Given this counterintuitive behavior,they present very particular character... Materials with a negative Poisson's ratio(PR)are called auxetics;they are characterized by expansion/contraction when tensioned/compressed.Given this counterintuitive behavior,they present very particular characteristics and mechanical behavior.Geometrical models have been developed to justify and artificiall reproduce such materials' auxetic behavior.The focus of this study is the exploration of a reentrant model by analyzing the variation in the PR of reentrant structures as a function of geometrical and base material parameters.It is shown that,even in the presence of protruding ribs,there may not be auxetic behavior,and this depends on the geometry of each reentrant structure.Values determined for these parameters can be helpful as approximate reference data in the design and fabrication of auxetic lattices using reentrant geometries. 展开更多
关键词 Auxetic Poisson’s ratio Reentrant Finite element analysis Elasticity
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Ore Genesis for Stratiform Ore Bodies of the Dongfengnanshan Copper Polymetallic Deposit in the Yanbian Area, NE China:Constraints from LA-ICP-MS in situ Trace Elements and Sulfide S–Pb Isotopes 被引量:3
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作者 LU Siyu REN Yunsheng +3 位作者 YANG Qun SUN Zhenming HAO Yujie SUN Xinhao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第5期1591-1606,共16页
The Dongfengnanshan Cu polymetallic deposit is one representative deposit of the Tianbaoshan ore district in the Yanbian area, northeast(NE) China. There occur two types of ore bodies in this deposit, the stratiform o... The Dongfengnanshan Cu polymetallic deposit is one representative deposit of the Tianbaoshan ore district in the Yanbian area, northeast(NE) China. There occur two types of ore bodies in this deposit, the stratiform ore bodies and veintype ones, controlled by the Early Permian strata and the Late Hercynian diorite intrusion, respectively. Due to the ambiguous genetic type of the stratiform ore bodies, there has been controversy on the relationship between them and veintype ore bodies. To determine the genetic type of stratiform ore bodies, laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) in situ trace elements and S–Pb isotope analysis have been carried on the sulfides in the stratiform ore bodies. Compared with that in skarn, Mississippi Valley-type(MVT), and epithermal deposits, sphalerite samples in the stratiform ore bodies of the Dongfengnanshan deposit are significantly enriched in Fe, Mn, and In, while depleted in Ga, Ge, and Cd, which is similar to the sphalerite in volcanic-associated massive sulfide(VMS) deposits. Co/Ni ratio of pyrrhotites in the stratiform ore bodies is similar to that in VMS-type deposits. The concentrations of Zn and Cd of chalcopyrites are similar to those of recrystallized VMS-type deposits. These characteristics also reflect the intermediate ore-forming temperature of the stratiform ore bodies in this deposit. Sulfur isotope compositions of sulfides are similar to those of VMS-type deposits, reflecting that sulfur originated from the Permian Miaoling Formation. Lead isotope compositions indicate mixed-source for lead. Moreover, the comparison of the Dongfengnanshan stratiform ore bodies with some VMStype deposits in China and abroad, on the trace elements and S–Pb isotope characteristics of the sulfides reveals that the stratiform ore bodies of the Dongfengnanshan deposit belong to the VMS-type, and have closely genetic relationship with the early Permian marine volcanic sedimentary rocks. 展开更多
关键词 LA-ICP-Ms in situ trace element s-Pb isotope VMs-type sTRATIFORM orebodies Dongfengnanshan copper POLYMETALLIC deposit Tianbaoshan ORE district
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Finite Element Analysis of Diamond Saw Blades to Prevent Steel Base Wear
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作者 HU Ying-ning 1,WANG Cheng-yong 2,WEI Xin 2,LI Zhi-guo 1 (1.Department of Mechanical Engineering,Guangxi University,Nanning 530 004,China 2.Department of Mechanical Engineering,Guangdong University of Technol ogy, Guangzhou 510090,China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期299-,共1页
The FEM analysis of stress and deformation of steel base of the special diamond saw blades are carried out.The small carbide round segments are welded on the side of blades in order to increase the side wear re sistan... The FEM analysis of stress and deformation of steel base of the special diamond saw blades are carried out.The small carbide round segments are welded on the side of blades in order to increase the side wear re sistance of blade.Comparing with conventional saw blade,the maximum stress val ues of reasonable special saw blade are reduced respectively about 17%20% 33%,and the maximum deformation values are reduced respectively about 26%22 %44.7%in thetangential(X),radial(Y)and axial(Z)direction.The stress conce ntration zone is decreased for the special structure diamond saw blade.The stru ctures of diamond saw blade with different number of hard material pellet are an alyzed and optimized. 展开更多
关键词 diamond saw blades side wear finite element analysi s
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A simplified two-dimensional boundary element method with arbitrary uniform mean flow 被引量:2
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作者 Bassem Barhoumi Safa Ben Hamouda Jamel Bessrour 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第4期207-221,共15页
To reduce computational costs, an improved form of the frequency domain boundary element method(BEM) is proposed for two-dimensional radiation and propagation acoustic problems in a subsonic uniform flow with arbitr... To reduce computational costs, an improved form of the frequency domain boundary element method(BEM) is proposed for two-dimensional radiation and propagation acoustic problems in a subsonic uniform flow with arbitrary orientation. The boundary integral equation(BIE) representation solves the two-dimensional convected Helmholtz equation(CHE) and its fundamental solution, which must satisfy a new Sommerfeld radiation condition(SRC) in the physical space. In order to facilitate conventional formulations, the variables of the advanced form are expressed only in terms of the acoustic pressure as well as its normal and tangential derivatives, and their multiplication operators are based on the convected Green's kernel and its modified derivative. The proposed approach significantly reduces the CPU times of classical computational codes for modeling acoustic domains with arbitrary mean flow. It is validated by a comparison with the analytical solutions for the sound radiation problems of monopole,dipole and quadrupole sources in the presence of a subsonic uniform flow with arbitrary orientation. 展开更多
关键词 Two-dimensional convected Helmholtz equation Two-dimensional convected Green’s function Two-dimensional convected boundary element method Arbitrary uniform mean flow Two-dimensional acoustic sources
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波纹管参数对TRB管胀形S型波纹管壁厚分布的影响
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作者 何滔 顾栩 《机械设计与制造工程》 2023年第4期130-134,共5页
为研究TRB管无轴向补料胀形S型波纹管壁厚分布影响因素,通过理论设计构建了TRB管坯参数与S型波纹管参数的几何关系,并建立了胀形有限元模型。研究了S型波纹管参数波纹圆心角、波纹曲率半径、波纹管内半径对壁厚分布的影响。圆心角增大时... 为研究TRB管无轴向补料胀形S型波纹管壁厚分布影响因素,通过理论设计构建了TRB管坯参数与S型波纹管参数的几何关系,并建立了胀形有限元模型。研究了S型波纹管参数波纹圆心角、波纹曲率半径、波纹管内半径对壁厚分布的影响。圆心角增大时,设计壁厚与最大壁厚的差(正差)、与最小壁厚的差(负差)以及最大壁厚与最小壁厚的差(总差)快速增大,圆心角对壁厚分布影响显著。当圆心角为42°时,负差为设计壁厚的11.4%,总差为19.3%,壁厚分布不均匀。曲率半径和波纹管内半径对壁厚分布影响不显著,合理的参数范围内,TRB管胀形S型波纹管壁厚分布均匀。 展开更多
关键词 s型波纹管 TRB管 液压胀形 有限元 壁厚均匀
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Are spatial distributions of major elements in soil influenced by human landscapes?
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作者 Huan Yu Zhengwei He +1 位作者 Zeming Shi Bo Kong 《Acta Geochimica》 EI CAS CSCD 2018年第4期571-577,共7页
The present study attempted to evaluate the influence of human activity on major elements(Na_2O,MgO, Al_2O_3, SiO_2, K_2O, CaO, Fe_2O_3), and to find a method to explore correlations between major elements and human d... The present study attempted to evaluate the influence of human activity on major elements(Na_2O,MgO, Al_2O_3, SiO_2, K_2O, CaO, Fe_2O_3), and to find a method to explore correlations between major elements and human disturbances, according to geospatial theories and methods. The study results indicate that landscapes influence major elements in diverse ways: Al_2O_3 is closely related to road and mine landscapes; strong relationships exist between MgO, Fe_2O_3, CaO, and SiO_2 and roads;Na_2O, SiO_2, and Fe_2O_3 are unrelated to city landscapes;and Na_2O is unrelated to road and mine landscapes. 展开更多
关键词 城市风景 元素 空间分布 FE2O3 土壤 sIO2 NA2O FE2O3
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Development of China's Public Health as an Essential Element of Human Rights 被引量:1
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《The Journal of Human Rights》 2017年第6期612-635,共24页
September 2017 Contents Preface Ensuring People’s Right to Health Based on China’s Conditions Continuous Improvement of Health Environment and Conditions Public Health Service Capability Improving Steadily Great Imp... September 2017 Contents Preface Ensuring People’s Right to Health Based on China’s Conditions Continuous Improvement of Health Environment and Conditions Public Health Service Capability Improving Steadily Great Improvement in the Quality of Medical and Health Services Improvement of the National Medical Security System 展开更多
关键词 In Development of China’s Public Health as an Essential element of Human Rights
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滇西兰坪金顶铅锌矿床精细刻画矿化过程:来自硫化物原位微量元素和S-Pb同位素的证据
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作者 李相材 王京彬 +5 位作者 祝新友 李成厚 吴金检 王永彬 石珉 郭宇航 《岩石学报》 SCIE EI CAS CSCD 北大核心 2023年第8期2511-2532,共22页
金顶铅锌矿床位于中国西南中新生代兰坪盆地,是亚洲第二大铅锌矿床,其巨大的储量和复杂的地质成矿史吸引了众多学者的研究,但在矿床成因和矿化过程的精细描述等方面仍存在较大争议。本文通过详细的野外地质调查并结合硫化物的LA-(MC)ICP... 金顶铅锌矿床位于中国西南中新生代兰坪盆地,是亚洲第二大铅锌矿床,其巨大的储量和复杂的地质成矿史吸引了众多学者的研究,但在矿床成因和矿化过程的精细描述等方面仍存在较大争议。本文通过详细的野外地质调查并结合硫化物的LA-(MC)ICP-MS微量元素和硫、铅同位素分析对该矿床进行了详细解剖。金顶铅锌矿床的含矿地层为景星组砂岩、云龙组含砾砂岩及灰岩角砾岩。成矿过程可分为2个主要阶段:第Ⅰ阶段早期为浸染状的黄铁矿-白铁矿-闪锌矿-方铅矿,晚期硫化物呈块状且出现天青石;第Ⅱ阶段为闪锌矿-方铅矿-黄铁矿-天青石-重晶石-方解石-石膏阶段。成矿过程中硫化物的原位微量元素和S-Pb同位素表现出规律演化特征。主要金属元素除了以简单的类质同象形式赋存于闪锌矿中,Zn^(2+)与微量元素存在4Zn^(2+)→2Fe^(2+)→Ge^(4+)、2Zn^(2+)→Fe2+→Mn^(2+)、3Zn^(2+)→In^(3+)→Sn^(3+)等复杂的替代关系。综合微量元素和S-Pb同位素演化规律,本文认为金顶铅锌矿的成矿流体早阶段与富含金属的盆地卤水和富含H2S的流体有关,晚阶段则与大气水的混入有关。在后一过程中,大气水萃取了区域上富含Fe、Mn、Tl的红层碎屑岩,进而导致Fe、Mn、Tl等元素含量的升高,同时闪锌矿也表现出更宽范围的微量元素特征和更窄范围的^(208)Pb/^(204)Pb、^(207)Pb/^(204)Pb和δ^(34)S值的特征。由此推断,超大型金顶铅锌矿床是由多来源流体相互叠加而形成,其成矿物质主要来源于兰坪盆地沉积地层。此外,BSR作用在硫酸盐还原过程中起着重要作用,西部矿段还原硫可能还有少量TSR作用的贡献。最后,本文讨论了金顶铅锌矿床的矿床成因和精细矿化过程,综合分析认为它是一个受层间构造控制的、富Cd和Ge等多种分散元素的后生碎屑岩容矿型MVT铅锌矿床。 展开更多
关键词 金顶铅锌矿床 LA-(MC)ICP-Ms 微量元素 s-Pb同位素 MVT型矿床
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Feasibility of a New Granular Rapid Release Elemental S Fertilizer in Preventing S Deficiency of Canola on a S-Deficient Soil
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作者 Sukhdev S. Malhi Cecil L. Vera Stewart A. Brandt 《Agricultural Sciences》 2014年第11期1025-1036,共12页
Our previous research has indicated that granular elemental S (ES) fertilizers are not effective in the year of application and also are not consistently as effective as sulphate-S in increasing seed yield of canola i... Our previous research has indicated that granular elemental S (ES) fertilizers are not effective in the year of application and also are not consistently as effective as sulphate-S in increasing seed yield of canola in subsequent years, especially when applied at seeding in spring, because of slow dispersion of elemental S particles from granules for subsequent oxidation of ES to sulphate-S. A field experiment was established in autumn 2010 to determine the relative effectiveness of a new rapid release elemental S (RRES, now called Vitasul) fertilizer, in comparison to sulphate-S fertilizer, with various combinations of application times and placement methods (applied at 20 kg&middotS&middotha-1) on seed yield, straw yield, oil and protein concentration in seed, N and S uptake, partial factor productivity (PFP—kg&middotseed&middotkg-1 applied N&middotha-1—blanket application of 120 kg&middotN&middotha-1), S use efficiency (SUE—increase in kg&middotseed&middotkg-1 applied S&middotha-1) and percent recovery of applied S in seed + straw (%) of canola in 2011, 2012 and 2013 growing seasons on a S-deficient Gray Luvisol loam soil at Star City, Saskatchewan. The 11 treatments included two granular S sources (RRES and potassium sulphate) and five application time/placement method combinations (broadcast in autumn and incorporated in spring, broadcast in spring pre-tillage [broadcast and incorporated], broadcast in spring pre-emergence, sideband in spring and seedrow-placed in spring), plus a zero-S control. There was a significant response of seed yield of canola to applied S in all 3 years, but the responses varied with S source and with application time-placement combinations in different years. Seed yield increased considerably with all sulphate-S treatments compared to the zero-S control, although seed yield tended to be slightly lower in some spring and/or autumn broadcast treatments than the other sulphate-S treatments. Compared to the zero-S control, seed yield also increased significantly with all RRES treatments, but the increase was greater with autumn applied RRES than the spring applied RRES in many cases. Autumn applied RRES produced only slightly lower seed yield but spring applied RRES produced much lower seed yield than the highest yielding spring applied sulphate-S treatments. In 2011, straw yields increased significantly with applied S in some S treatments, but there was no significant effect of S fertilization on straw yield in 2012 and 2013. Oil concentration in canola seed increased only with sulphate-S fertilizer treatments in 2011, and it increased with both sulphate-S and ES sources in 2012 and 2013. There was no effect of any S treatment on the protein concentration in canola seed. The response trends of total N uptake and PFP were usually similar to seed yield for both S sources, but total S uptake, SUE and % recovery of applied S were lower with RRES than sulphate-S in many/most cases. In conclusion, the findings suggested the potential of spring broadcast pre-emergence RRES or autumn broadcast RRES in preventing S deficiency in hybrid canola, although seed yields were still slightly lower than the ideal highest yielding spring broadcast/incorporated sulphate-S treatment. 展开更多
关键词 CANOLA elementAL s N UPTAKE Oil Protein seed Yield sulphate-s s-Deficiency s UPTAKE
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Analytical solutions for the slow neutron capture process of heavy element nucleosynthesis
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作者 吴开谡 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期4049-4057,共9页
In this paper, the network equation for the slow neutron capture process (s-process) of heavy element nucleosynthesis is investigated. Dividing the s-process network reaction chains into two standard forms and using... In this paper, the network equation for the slow neutron capture process (s-process) of heavy element nucleosynthesis is investigated. Dividing the s-process network reaction chains into two standard forms and using the technique of matrix decomposition, a group of analytical solutions for the network equation are obtained. With the analytical solutions, a calculation for heavy element abundance of the solar system is carried out and the results are in good agreement with the astrophysical measurements. 展开更多
关键词 s-PROCEss network equation analytical solution element abundance
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Breakthrough in the China's Separation Technology for Extraction of Rare Earth Elements
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作者 HAO Ziguo FEI Hongcai +1 位作者 LIU Lian Susan TURNER 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第6期1743-1744,共2页
Separation technology of rare earth elements (REEs), as the critical step in the separation process, had long been fraught with technical difficulty. A research project conducted by Baotou Shibo Rare Earth Extracti... Separation technology of rare earth elements (REEs), as the critical step in the separation process, had long been fraught with technical difficulty. A research project conducted by Baotou Shibo Rare Earth Extraction & Equipment Co. Ltd., Baotou REE Research Institute, and Baotou Steel & REE Group Hi-Tech Co. Ltd (Inner Mongolia), has successfully solved the problem using a centrifugal extractor and advanced techniques to achieve a key breakthrough. 展开更多
关键词 LINE Breakthrough in the China’s separation Technology for Extraction of Rare Earth elements REE
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A FINITE ELEMENT ADAPTIVE METHOD FOR SOLVING GENERALIZED STOKES PROSLEM
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作者 D. A.Fokin Yang Zuosheng(Department of Aerodynamics ,NUAA 29 Yudao Street.Nanjing 21001 P.China) 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1994年第1期1-6,共6页
A stabilized and convergent finite element formulation for the generalized Stokes problem is proposed and a posteriori analysis is performed to produce an error indicator. On this basis adaptive numerical method for s... A stabilized and convergent finite element formulation for the generalized Stokes problem is proposed and a posteriori analysis is performed to produce an error indicator. On this basis adaptive numerical method for solying the problem is developed . Numerical calculations are performed to confirm the reliability and effectiveness of the method. 展开更多
关键词 FINITE element method error EsTIMATE N-s e-quation generalized sTOKEs problems adaptive FINITE element methods
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SWRCH35K自冲铆接的失效分析与疲劳寿命预测
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作者 李萍 宋杰 《农业装备与车辆工程》 2023年第8期159-162,共4页
针对某车机械离合器SWRCH35K铆接结构在做耐久台架试验时发生断裂问题,通过疲劳寿命预测分析其影响因素;建立离合器铆钉有限元模型,对其施加边界条件,进行有限元分析,根据分析结果进行结构优化设计。结果表明:直径φ4的铆钉CAE疲劳寿命... 针对某车机械离合器SWRCH35K铆接结构在做耐久台架试验时发生断裂问题,通过疲劳寿命预测分析其影响因素;建立离合器铆钉有限元模型,对其施加边界条件,进行有限元分析,根据分析结果进行结构优化设计。结果表明:直径φ4的铆钉CAE疲劳寿命在65万次左右,不满足100万次的要求;优化设计后,直径φ5的铆钉CAE疲劳寿命达到200万次左右,满足设计要求,与台架试验结论一致。由此说明,采用有限元技术预测铆钉疲劳寿命可行,可为离合器铆接设计提供参考。 展开更多
关键词 sWRCH35K 自冲铆接 有限元 s-N曲线 疲劳寿命
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