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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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On the Error Estimate of Adini's Element for the Second Order Problems 被引量:1
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作者 高继梅 李文华 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第3期364-369,共6页
The main aim of this paper is to have an accurate analysis on the famous Adini's element for the second order problems under to the anisotropic meshes. We firstly show that the interpolation of Adini's element satis... The main aim of this paper is to have an accurate analysis on the famous Adini's element for the second order problems under to the anisotropic meshes. We firstly show that the interpolation of Adini's element satisfy the anisotropic property. Then the optimal error estimate is obtained without the regularity assumption on the meshes. 展开更多
关键词 Adini's element ANIsOTROPIC regularity assumption error estimate
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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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2021年青海玛多M_(S)7.4地震震后余滑有限元数值模拟
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作者 魏巍 谭凯 +3 位作者 熊维 鲁小飞 张彩红 李承涛 《地震研究》 北大核心 2026年第1期92-99,共8页
2021年青海玛多发生的M_(S)7.4地震,是近30年来巴颜喀拉块体内唯一的1次强地震,震后形变显著,对区域构造运动和地震活动有很大的影响。采用速率强化摩擦准则的应力驱动余滑模型,建立玛多M_(S)7.4地震断层的三维有限元网格模型,以震后6个... 2021年青海玛多发生的M_(S)7.4地震,是近30年来巴颜喀拉块体内唯一的1次强地震,震后形变显著,对区域构造运动和地震活动有很大的影响。采用速率强化摩擦准则的应力驱动余滑模型,建立玛多M_(S)7.4地震断层的三维有限元网格模型,以震后6个月GPS形变资料为约束,研究震后形变的动力学参数。首先计算玛多M_(S)7.4地震断层的同震剪切应力,以此作为震后余滑的驱动源,正演震后余滑,探究震后断层最佳参考滑动速率和摩擦参数。结果表明:余滑与同震破裂在空间分布上有一定的互补关系,余滑主要集中在同震滑动的下倾区域,10~20 km深度范围内的余滑约占震后余滑总量的80%,最大滑动量达到1.1 m。最佳参考滑动速率V_(0)=400 mm/a,摩擦本构参数aσ=0.4 MPa。 展开更多
关键词 玛多M_(s)7.4地震 震后余滑 应力驱动 有限元数值模拟
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Anisotropic Interpolation Error Estimates of a Nonconforming Element
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作者 汪远征 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第2期232-235,共4页
The main aim of this paper is to study the local anisotropic interpolation error estimates. We show that the interpolation of a nonconforming element satisfy the anisotropic property for both the second and fourth ord... The main aim of this paper is to study the local anisotropic interpolation error estimates. We show that the interpolation of a nonconforming element satisfy the anisotropic property for both the second and fourth order problems. 展开更多
关键词 Adini's element anisotropic interpolation error estimates
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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:4
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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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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 (Na2O, MgO, A1203, SiO2, K2O, CaO, Fe203), and to find a method to explore correlations between major elements and human dist... The present study attempted to evaluate the influence of human activity on major elements (Na2O, MgO, A1203, SiO2, K2O, CaO, Fe203), 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: Al2O3 is closely related to road and mine landscapes; strong relationships exist between MgO, Fe2O3, CaO, and SiO2 and roads; Na2O, SiO2, and Fe2O3 are unrelated to city landscapes; and Na2O is unrelated to road and mine landscapes. 展开更多
关键词 s Major elements spatial distribution Geographical background Human landscape Geographic information system Remote sensing
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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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鄂尔多斯盆地东北部奥陶系马家沟组盐下烃源岩黄铁矿成因及对氧化还原条件的启示:来自微区原位S—Fe同位素和微量元素的证据
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作者 秦彪 范立勇 +9 位作者 苏亭 魏柳斌 贾连奇 王前平 罗晓容 郑睿宁 张洁 王怡帅 贺涛 池皓楠 《天然气地球科学》 北大核心 2025年第8期1586-1601,共16页
近年来,鄂尔多斯盆地东北部奥陶系海相碳酸盐岩作为潜在烃源岩,其地球化学基本特征和生烃潜力已被广泛研究。然而,关于烃源岩沉积古环境的氧化还原条件仍存在争议。为了更合理地判识沉积古环境的氧化还原条件,对马家沟组盐下马三段烃源... 近年来,鄂尔多斯盆地东北部奥陶系海相碳酸盐岩作为潜在烃源岩,其地球化学基本特征和生烃潜力已被广泛研究。然而,关于烃源岩沉积古环境的氧化还原条件仍存在争议。为了更合理地判识沉积古环境的氧化还原条件,对马家沟组盐下马三段烃源岩(黄铁矿编号Py1和Py2)和马五6亚段(黄铁矿编号Py3)烃源岩中的黄铁矿进行岩石学、矿物学、微量元素、S-Fe同位素分析。结果表明:①马家沟组盐下烃源岩中黄铁矿主要为棒状集合体、致密椭圆状及自形—半自形3种形态,且Py1、Py2和Py3的Co/Ni值均小于1,为沉积成因黄铁矿。②黄铁矿的S同位素数据显示Py1、Py2和Py3均形成于缺氧—硫化的还原环境。其中Py1和Py3形成于硫酸盐含量充足的开放水体中,δ34S值小于-20‰。Py2的δ34S值相对较高,是受水体沉积物沉积速率较快影响。③Py1、Py2和Py3的δ56Fe值整体变化范围较大,反映了氧化还原环境的不均一性,与烃源岩沉积期海平面变化和陆源输入有关。其中马三段烃源岩形成于相对封闭的强还原环境,更有利于有机质的保存。研究明确了马家沟组盐下碳酸盐岩烃源岩中黄铁矿的成因、形成过程及烃源岩沉积期的氧化还原环境,该方法有助于深层碳酸盐烃源岩的古环境氧化还原条件分析。 展开更多
关键词 鄂尔多斯盆地 烃源岩 黄铁矿 微量元素 s-Fe同位素 氧化还原环境
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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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内蒙古甲乌拉矿床铅锌和钼铜矿化之间的成因联系:来自黄铁矿原位主微量元素和S同位素的制约
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作者 刘艳荣 王营枫 +4 位作者 孙贵远 周壹 李承泽 谈黄赟涛 玛依拉∙艾山 《地质学报》 北大核心 2025年第10期3533-3557,共25页
甲乌拉矿床作为额尔古纳地块的代表性铅锌多金属矿床之一,近年来在矿床深部斑岩体内发现了铜钼矿化,其成矿物质来源及其与浅部铅锌矿体之间的成因关系是目前研究的热点。本文拟采用扫描电镜、电子探针、LA-(MC)-ICP-MS等原位分析技术,... 甲乌拉矿床作为额尔古纳地块的代表性铅锌多金属矿床之一,近年来在矿床深部斑岩体内发现了铜钼矿化,其成矿物质来源及其与浅部铅锌矿体之间的成因关系是目前研究的热点。本文拟采用扫描电镜、电子探针、LA-(MC)-ICP-MS等原位分析技术,对矿床中各类型黄铁矿(Py1~Py4)的结构构造、化学成分及S同位素组成等进行分析,以揭示黄铁矿中元素的赋存状态和富集规律,并为判定成矿物质来源和矿床成因提供更多依据。根椐野外矿脉的穿插关系和室内矿相学研究,甲乌拉矿床热液成矿期可划分为四个成矿阶段:石英-黄铁矿阶段(Ⅰ)、石英-辉钼矿-黄铜矿-黄铁矿-闪锌矿阶段(Ⅱ)、石英-黄铁矿-闪锌矿-方铅矿-黄铜矿阶段(Ⅲ)和石英-方解石-黄铁矿阶段(VI)。各成矿阶段分别对应黄铁矿类型Py1~Py4。研究结果显示,各类黄铁矿中均富集Co、Ni等元素,它们主要以类质同象方式进入到黄铁矿晶格中;Py1和Py4内含有高含量的Na、Al、K和Ti等元素,这些元素可能多以微小氧化物或硅酸盐包裹体的形式存在;Py1和Py2中含有较高含量的Bi元素,Py4黄铁矿中Cu、Pb、Zn、Sb、Ag等成矿元素含量整体较高,它们可能多以微小硫化物或硫盐矿物包裹体的形式存在;Py3黄铁矿中微量元素不富集。黄铁矿原位δ^(34)S值组成为0.68‰~10.23‰,其中前三种黄铁矿及大部分Py4黄铁矿的δ^(34)S值均在0.68‰~4.83‰之间,表明它们可能均为深源岩浆来源;Py4黄铁矿中个别δ^(34)S值相对较高(7.81‰~10.23‰),推测浅部矿体局部可能存在壳源物质加入。结合前人研究成果,综合判断浅部铅锌矿化和深部铜钼矿化为同一地质事件演化的产物,与矿化直接相关的岩浆作用应为深部斑岩体。因此,在成因方面,笔者认为甲乌拉矿床属于斑岩-浅成热液型多金属矿床。 展开更多
关键词 黄铁矿 原位分析 微量元素 s同位素 甲乌拉
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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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不同S/N比下的硫自养反硝化工艺除磷性能及生物S^(0)作用机制
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作者 梁娜 张凯瑜 +4 位作者 朱晓鹏 张信 徐方健 孙泾浩 蔡靖 《环境科学学报》 北大核心 2025年第10期158-171,共14页
硫自养反硝化工艺不仅可实现低碳高效脱氮,还可实现磷酸盐的有效去除.本文主要探究了不同基质比例下硫自养反硝化工艺的氮、硫、磷去除性能,并解析系统中磷赋存形态和除磷途径.结果表明,当S/N比为3.0时,硫自养反硝化工艺可实现96.46%... 硫自养反硝化工艺不仅可实现低碳高效脱氮,还可实现磷酸盐的有效去除.本文主要探究了不同基质比例下硫自养反硝化工艺的氮、硫、磷去除性能,并解析系统中磷赋存形态和除磷途径.结果表明,当S/N比为3.0时,硫自养反硝化工艺可实现96.46%±1.81%的硝酸盐去除,94.94%±1.99%的硫化物去除和83.23%±1.24%的磷酸盐去除,且磷酸盐去除与生物单质硫具有显著正相关.SMT、XRD及SEM结果表明,除磷产物主要以无机磷(Mg_(3)(PO_(4))_(2)·10H_(2)O)的形式存在,除磷途径为生物诱导除磷(85.62%±3.83%)和生物除磷(14.38%±3.83%).批次试验结果证实了生物单质硫在磷酸盐去除过程中充当晶种作用,可有效加速晶体生长沉淀,并结合生物单质硫特性,基于xDLVO和DFT理论计算揭示了生物单质硫与磷酸盐之间的相互吸引力.宏基因组学结果表明,除磷相关基因丰度与磷酸盐去除之间存在显著正相关(p<0.05). 展开更多
关键词 硫自养反硝化工艺 除磷性能 s/N比例 单质硫 晶种
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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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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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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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S-100系列产品要素目录及符号化通用模块的设计方法研究
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作者 卫国兵 林钒深 +1 位作者 姜悦 于桂菊 《中国海事》 2025年第4期53-57,共5页
通过研究S-100系列产品的要素目录及图示表达目录,设计要素目录读取及图示表达符号化通用模块,基本实现S-100系列产品通用的读取和符号化功能。
关键词 s-100 要素目录 图示表达目录 符号化 通用模块
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辽东鸭绿江金成矿带下河口金矿床成因:地质、S-Pb-He-Ar同位素和硫化物微量元素证据
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作者 俞炳 曾庆栋 +5 位作者 王永彬 苏菲 杨进辉 陈辉 张晓飞 王珺璐 《岩石学报》 北大核心 2025年第9期2897-2911,共15页
作为辽东地区鸭绿江金成矿带内首例赋存在古元古代辽河群高家峪组地层中的石英脉型金矿床,下河口金矿床成为揭示辽东地区华北克拉通破坏背景下金矿成矿理论和诱发区域矿产勘查突破的重要引子之一。详细的地质调查表明,下河口金矿床受控... 作为辽东地区鸭绿江金成矿带内首例赋存在古元古代辽河群高家峪组地层中的石英脉型金矿床,下河口金矿床成为揭示辽东地区华北克拉通破坏背景下金矿成矿理论和诱发区域矿产勘查突破的重要引子之一。详细的地质调查表明,下河口金矿床受控于近南北向断裂,与闪长玢岩脉共存,成矿阶段可划分为乳白色石英阶段、石英-黄铁矿-黄铜矿阶段、石英-多金属硫化物阶段和石英-碳酸盐阶段。黄铁矿S同位素测试结果显示其δ^(34)S值为4.7‰~6.5‰,略高于典型地幔硫值,推测硫主要来源于岩浆硫。黄铁矿Pb同位素测试结果显示其^(208)Pb/^(204)Pb、207 Pb/^(204)Pb和206 Pb/^(204)Pb值分别为39.289~39.537、15.734~15.832和18.627~18.782,具有高的μ值,表明铅主要来源于浅部壳源。黄铁矿流体包裹体He-Ar同位素测试结果显示其3He/4He比值为0.13~0.72Ra,40 Ar/36 Ar比值为1285.6~2176.6,表明成矿流体以壳源流体为主,含少量幔源流体。硫化物微量元素测试结果显示成矿流体明显富As,Au在黄铁矿和毒砂中均明显富集。黄铁矿微量元素测试结果显示其有较高的Co/Ni和As/Ag比值和中等的Sb/Bi比值,表明黄铁矿主要为热液成因。综合区域已有年代学结果和本次研究结果,我们认为下河口金矿床属岩浆热液型金矿床,金成矿作用可能与华北克拉通破坏导致的早白垩世岩浆作用密切相关。 展开更多
关键词 下河口金矿床 鸭绿江金成矿带 s-Pb同位素 HE-AR同位素 微量元素
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