检索结果-南通市图书馆

Rheological properties and concentration evolution of thickened tailings under the coupling effect of compression and shear

引用

International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 862-876页

作者： Aixiang Wu Zhenqi Wang Zhuen Ruan raimund bürger Shaoyong Wang Yi Mo Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China CI2MA and Departamento de Ingeniería Matemática Facultad de Ciencias Físicas y MatemáticasUniversidad de ConcepciónCasilla 160-CConcepciónChile School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China China Railway Construction Tongguan Investment Co. Ltd.Tongling 244000China

Cemented paste backfill(CPb)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPb ***,difficult flocculation and substandard concentrations of thickened tailings often *** rheological properties and concentration evolution in the thickened tailings remain ***,traditional indoor thickening experiments have yet to quantitatively characterize their rheological *** experiment of flocculation condition optimization based on the box-behnken design(bbD)was performed in the study,and the two response values were investigated:concentration and the mean weighted chord length(MWCL)of ***,optimal flocculation conditions were *** addition,the rheological properties and concentration evolution of different flocculant dosages and ultrafine tailing contents under shear,compression,and compression-shear coupling experimental conditions were tested and *** results show that the shear yield stress under compression and compression-shear coupling increases with the growth of compressive yield stress,while the shear yield stress increases slightly under *** order of shear yield stress from low to high under different thickening conditions is shear,compression,and compression-shear *** compression and compression-shear coupling,the concentration first rapidly increases with the growth of compressive yield stress and then slowly increases,while concentration increases slightly under *** order of concentration from low to high under different thickening conditions is shear,compression,and compression-shear ***,the evolution mechanism of the flocs and drainage channels during the thickening of the thickened tailings under different experimental conditions was revealed.

关键词： thickened tailings compression-shear coupling compressive yield stress shear yield stress concentration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of variations in the polar and azimuthal angles of coarse particles on the structure of drainage channels in thickened beds

引用

International Journal of Minerals,Metallurgy and Materials 2023年第12期30卷 2321-2333页

作者： Cuiping Li Gezhong Chen Zhu’en Ruan raimund bürger Yuan Gao Hezi Hou Hui Wang Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China CI2MA and Departamento de Ingeniería Matemática Facultad de Ciencias Físicas y MatematicasUniversidad de ConcepcionCasilla 160-CConcepciónChile School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

The 3D reconstruction and quantitative characterization of drainage channels and coarse tailings particles in a bed were conducted in this *** influence of variations in the azimuthal angle(θ)and polar angle(φ)of coarse particles on drainage channel structure was analyzed,and the drainage mechanism of the bed was *** showed that water discharge in the bed reduced the size of pores and throat channels,increasing slurry *** throat channel structure was a key component of the drainage ***φandθof particles changed predominantly along the length *** changes inφhad a cumulative plugging effect on the drainage channel and increased the difficulty of water *** rake and rod formed a shear ring in the tailings bed with shear,and theθdistribution of particles changed from disorderly to orderly during the rotation *** drainage channel was squeezed during the shearing process with the change inθ,which broke the channel structure,encouraged water discharge in the bed,and facilitated a further increase in slurry *** findings of this work are expected to offer theoretical guidance for preparing high-concentration underflow in the tailings thickening process.

关键词： tailings thickening coarse particle azimuthal angle polar angle drainage channels

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improvement of center segregation in high-carbon steel billets using soft reduction

引用

Journal of University of Science and Technology beijing 2006年第6期13卷 490-496页

作者： Wenjun Wang Xionggang Hu Linxin Ning raimund bülte Wolfgang bleck Institute of Ferrous Metallurgy RWTH Aachen University Intzestrasse 1 52072 Aachen Germany Shougang Group Research Institute Beijing 100041 China

Center segregation is the main reason for cup fracture of high-carbon wire rod during drawing. Therefore, to continuously produce cast billets with very low center segregation is an important objective. The soft reduction technology is considered to be an effective method to minimize center segregation. To elucidate the effect of soft reduction on the internal quality of high-carbon steel billets, soft reduction was applied with different solid fractions in the core area of billets in a laboratory casting machine. A coupled temperature/displacement finite element model was developed to calculate the solid fraction using the commercial software AbAQUS. Center segregation, center porosity, homogeneity of elements, and equiaxed crystal zone were obviously improved by applying soft reduction, especially when the solid fraction was less than 1.0. The optimal results were obtained when the solid fraction was approximately 0.9.

关键词： steel 100Cr6 centre segregation soft reduction finite element model internal cracks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structure of Hyperbolic Unitary Groups II： Classification of E-Normal Subgroups

引用

Algebra Colloquium 2017年第2期24卷 195-232页

作者： raimund Preusser Mathematics Department University of Bielefeld 33615 Bielefeld Germany

Abstract. This paper proves the sandwich classification conjecture for subgroups of an even dimensional hyperbolic unitary group U2n（R, A） which are normalized by the elementary subgroup EU2n（R, A）, under the condition that R is a quasi-finite ring with involution, i.e., a direct limit of module finite rings with involution, and n ≥ 3. 2010 Mathematics Subject Classification： 20G35, 20H25

关键词： unitary groups E-normal subgroups sandwich classification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Formation of internal cracks in steel billets during soft reduction

引用

Journal of University of Science and Technology beijing 2008年第2期15卷 114-119页

作者： Wenjun Wang Linxin Ning raimund biilte Wolfgang bleek Institute of Ferrous Metallurgy RWTH Aachen University Aachen 52072 Germany Shougang Group Research Institute Beijing 100041 China

To investigate the formation of internal cracks in steel billets during soft reduction, fully coupled thermo-mechanical finite element models were developed using the commercial software AbAQUS, also casting and soft reduction tests were carried out in a laboratory strand casting machine. With the finite element models, the temperature distribution, the stress and strain states in the billet were calculated. The relation between internal cracks and equivalent plastic strain, as well as maximal principal stress was analyzed. The results indicate that tensile stresses can develop in the mushy zone during soft reduction and the equivalent strain nearby the zero ductility temperature （ZDT） increases with decreasing solid fraction. Internal cracks can be initiated when the accumulated strain exceeds the critical strain or the applied tensile stress exceeds the critical fracture stress during solidification.

关键词： steel soft reduction finite element model internal cracks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Approximation of Oscillatory Solutions of Hyperbolic-Elliptic Systems of Conservation Laws by Multiresolution Schemes

引用

Advances in Applied Mathematics and Mechanics 2009年第5期1卷 581-614页

作者： Stefan berres raimund burger Alice Kozakevicius Departamento de Ciencias Matematicas y Fısicas Universidad Catolica de TemucoTemucoChile CI2MA and Departamento de Ingenier´ıa Matem´atica Facultad de Ciencias Fısicas y Matem´aticasUniversidad de Concepci´onCasilla 160-CConcepci´onChile Departamento de Matematica-CCNE Universidade Federal de Santa MariaAv.Roraima1000Campus Universit´arioSanta MariaRSCEP 97105-900Brazil

The generic structure of solutions of initial value problems of hyperbolic-elliptic systems,also called mixed systems,of conservation laws is not yet fully *** reason for the absence of a core well-posedness theory for these equations is the sensitivity of their solutions to the structure of a parabolic regularization when attempting to single out an admissible solution by the vanishing viscosity *** is,however,theoretical and numerical evidence for the appearance of solutions that exhibit persistent oscillations,so-called oscillatory waves,which are(in general,measure-valued)solutions that emerge from Riemann data or slightly perturbed constant data chosen from the interior of the elliptic *** capture these solutions,usually a fine computational grid is *** this work,a version of the multiresolution method applied to a WENO scheme for systems of conservation laws is proposed as a simulation tool for the efficient computation of solutions of oscillatory wave *** hyperbolic-elliptic 2×2 systems of conservation laws considered are a prototype system for three-phase flow in porous media and a system modeling the separation of a heavy-buoyant bidisperse *** the latter case,varying one scalar parameter produces elliptic regions of different shapes and numbers of points of tangency with the borders of the phase space,giving rise to different kinds of oscillation waves.

关键词： Hyperbolic-elliptic system conservation law oscillation wave numerical simulation multiresolution method sedimentation model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Test Time Minimization for Hybrid bIST of Core-based Systems

引用

Journal of Computer Science & Technology 2006年第6期21卷 907-912页

作者： Gert Jervan Petru Eles Zebo Peng raimund Ubar Maksim Jenihhin Embedded Systems Laboratory (ESLAb) Linkoeing University Sweden Department of Computer Engineering Tallinn University of Technology Estonia

This paper presents a solution to the test time minimization problem for core-based systems. We assume a hybrid bIST approach, where a test set is assembled, for each core, from pseudorandom test patterns that are generated online, and deterministic test patterns that are generated off-line and stored in the system. In this paper we propose an iterative algorithm to find the optimal combination of pseudorandom and deterministic test sets of the whole system, consisting of multiple cores, under given memory constraints, so that the total test time is minimized. Our approach cmploys a fast estimation methodology in order to avoid exhaustive search and to speed-up the calculation process. Experimental results have shown the efficiency of the algorithm to find near optimal solutions.

关键词： SoC self-test hybrid bIST

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Diffusively Corrected Multiclass Lighthill-Whitham-Richards Traffic Model with Anticipation Lengths and Reaction Times

引用

Advances in Applied Mathematics and Mechanics 2013年第5期5卷 728-758页

作者： raimund burger Pep Mulet Luis M.Villada CI2MA and Departamento de Ingenierıa Matematica Facultad de Ciencias Fısicas y MatematicasUniversidad de ConcepcionCasilla 160-CConcepcionChile Departament de Matematica Aplicada Universitat de ValenciaAv.Dr.Moliner 50E-46100 BurjassotSpain

Multiclass Lighthill-Whitham-Richards trafficmodels[benzoni-Gavage and Colombo,***.,14(2003),pp.587–612;Wong and Wong,***.A,36(2002),pp.827–841]give rise to first-order systems of conservation laws that are hyperbolic under usual conditions,so that their associated Cauchy problems are *** lengths and reaction times can be incorporated into these models by adding certain conservative second-order terms to these first-order conservation *** terms can be diffusive under certain circumstances,thus,in principle,ensuring the stability of the *** purpose of this paper is to analyze the stability of these diffusively correctedmodels under varying reaction times and anticipation *** is demonstrated that instabilities may develop for high reaction times and short anticipation lengths,and that these instabilities may have controlled frequencies and amplitudes due to their nonlinear nature.

关键词： Traffic flow multispecies model anticipation length reaction time diffusive correction quasilinear system of second-order PDEs stability numerical simulation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

GLObAL HISTORY, ENTANGLED AREAS, CULTURAL CONTACTS–AND THE ANCIENT WORLD

引用

Journal of Ancient Civilizations 2018年第1期33卷 115-130页

作者： raimund Schulz Uwe Walter University of bielefeld

Intertwined Institutions:Slavery as an Example While Global History and Entangled History are nowadays very much focused on modern times,there is a central area in which ancient history has set the pace for research since the 18th century:*** was common in many parts of the world up to the 19th century,it connected regions that were far apart,and it had drastic repercussions on both the"delivering"and the"receiving"areas.

关键词：历史纠缠文化中央区域古代史时间

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Growth of the tropical Pinus kesiya as influenced by climate and nutrient availability along an elevational gradient

引用

Journal of Plant Ecology 2020年第1期13卷 97-106页

作者： Le Tuan Ho raimund Schneider Frank M.Thomas Department of Geobotany University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany Department of Forest Resources Management Faculty of ForestryNong Lam University HCMCThu Duc DistrictHo Chi Minh CityVietnam Department of Soil Science University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany

Aims In contrast to temperate regions,the reasons for growth reductions of individual tree species along elevational gradients in tropical mountain ranges are poorly known,especially for tropical *** aimed at testing whether climatic or edaphic conditions are responsible for the reduced growth of Pinus kesiya,a widely distributed pine species of southern and south-eastern Asia,at higher *** We analysed the stem diameter increment and the isotope discrimination against ^(13)C(△^(13)C)in tree rings of *** along an elevational gradient of~900 to~2000 m *** the mountain ranges of South-Central Vietnam,and related growth to△^(13)C and to climatic and edaphic *** findings We found no consistent correlation patterns between the basal area increment(bAI)of the trees and temperature or *** contrast,across the elevational gradient,we obtained significantly negative correlations of bAI with△^(13)C and with the C/N ratios and theδ^(15)N signature of the upper mineral *** was positively correlated with the concentrations of plant-available phosphorus(P_(a))and of“base”cations(calcium,magnesium,potassium)in the *** conclude that lower temperatures at higher elevations exert an indirect effect on tree growth by inducing higher C/N ratios and by reducing the rate of nitrogen(N)and P mineralization,which may be further hampered by lower concentrations of“base”cations(upon enhanced leaching by precipitation)and a negative feedback from low availability of mineralized N and P at higher *** results may be transferable to the uppermost growth limit of *** and to other montane regions of the species’occurrence.

关键词： dendroecology pine pointer year soil nutrient stable isotope

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：