检索结果-南通市图书馆

Thermal Performances of High-Temperature Thermal Energy Storage System with Tin Embedded in Copper Matrix by Theoretical Methods

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第5期31卷 1327-1336页

作者： LAN Yingying HUANG Congliang GUO Chuwen Jiangsu Province engineering Laboratory of High Efficient Energy Storage technology and Equipments China University of Mining and TechnologyXuzhou221116China School of electrical and Power engineering China University of Mining and TechnologyXuzhou221116China department of Mechanical engineering University of ColoradoBoulderColorado80309USA

There is a critical need to develop advanced high-temperature thermal storage systems to improve efficiencies and reduce the costs of solar thermal storage *** this work,two typical systems composed with Cu as matrix and Sn as the phase change material(PCM)are explored,namely,the 3-deimentional(3D)structure system by embedding Sn particles into Cu matrix and the 2-deimentional(2D)structure system by embedding Sn wires into Cu *** the thermophysical properties of a nanomaterial could be importantly different from that of a bulk one,we thus firstly derive the thermophysical properties of PCM and matrix theoretically,like the thermal conductivity by kinetic method and the specific heat capacity based on Lindemann’s *** then,these properties are utilized to estimate the energy storage ability in both 3D and 2D structure system,and the influence of structure on heat transfer efficiency is theoretically investigated in both 3D and 2D structure *** turn out that 3D structure system is a better choice than a 2D structure system,because of larger specific surface area,a larger sensitive heat capacity and a larger thermal *** the feature size of the PCM decreases to be less than a critical value which is about 500 nm for Sn,the thermal conductivity of the system decreases exponentially while the heat storage capacity increases ***,when the feature size of Sn geometry is less than a critical value,which is 15 nm for 3D structure system and 25 nm for 2D structure,the Cu matrix can’t play a role in improving the effective thermal conductivity of the whole system.

关键词： tin phase change material copper matrix kinetic method high-temperature thermal energy storage

Optimization of the fully grouted rock bolts for load transfer enhancement

在线全文

学校读者我要写书评

暂无评论

International Journal of mining Science and technology 2015年第5期25卷 707-712页

作者： Ghadimi Mostafa Shahriar Korosh Jalalifar Hossein department of mining engineering Tehran Science and Research BranchIslamic Azad University Faculty of mining Metallurgy and Petroleum EngineeringAmir Kabir University of Technology department of Petroleum and mining engineering Environmental and Energy Research CenterShahidBahonar University of Kerman

The purpose of this study is to investigate the role of bolt profile configuration in load transfer capacity between the bolt and ***,five types of rock bolts are used with different *** rock bolts are modeled by ANSYS *** show that profile rock bolt T_3 and T_ with load capacity 180 and 195 kN in the jointed rocks,are the optimum ***,the performances of the selected profiles are examined in Tabas Coal Mine by FLAC *** is good subscription between the results of numerical modeling and instrumentation reading such as tells tale,sonic extensometer and strain gauge rock *** to the finding of this study,the proposed pattern of rock bolts,on 7 + 6 patterns per meter with 2 flexi bolt(4 m) for support gate road.

关键词： Fully grouted rock bolts Numerical modeling Load transfer Bolt profile

A Survey of Underwater Multi-Robot Systems

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第1期9卷 1-18页

作者： Ziye Zhou Jincun Liu Junzhi Yu State Key Laboratory for Turbulence and Complex System Department of Advanced Manufacturing and RoboticsBeijing Innovation Center for Engineering Science and Advanced TechnologyCollege of EngineeringPeking UniversityBeijing 100871China College of Information and electrical engineering China Agricultural UniversityBeijing 100083China

As a cross-cutting field between ocean development and multi-robot system(MRS),the underwater multi-robot system(UMRS)has gained increasing attention from researchers and engineers in recent *** this paper,we present a comprehensive survey of cooperation issues,one of the key components of UMRS,from the perspective of the emergence of new *** specifically,we categorize the cooperation in terms of task-space,motion-space,measurement-space,as well as their ***,we analyze the architecture of UMRS from three aspects,i.e.,the performance of the individual underwater robot,the new functions of underwater robots,and the technical approaches of *** conclude,we have discussed related promising directions for future *** survey provides valuable insight into the reasonable utilization of UMRS to attain diverse underwater tasks in complex ocean application scenarios.

关键词： Cooperation formation control multi-robot systems(MRS) taxonomy underwater robots underwater tasks

Development of a multi-layer perceptron artificial neural network model to determine haul trucks energy consumption

在线全文

学校读者我要写书评

暂无评论

International Journal of mining Science and technology 2016年第2期26卷 285-293页

作者： Soofastaei Ali Aminossadati Saiied M. Arefi Mohammad M. Kizil Mehmet S. School of Mechanical and mining engineering.CRC mining The University of Queensland department of Power and Control engineering School of Electrical and Computer EngineeringShiraz University

The mining industry annually consumes trillions of British thermal units of energy,a large part of which is *** fuel is a significant source of energy in surface mining operations and haul trucks are the major users of this energy *** vehicle weight,truck velocity and total resistance have been recognised as the key parameters affecting the fuel *** this paper,an artificial neural network model was developed to predict the fuel consumption of haul trucks in surface mines based on the gross vehicle weight,truck velocity and total *** network was trained and tested using real data collected from a surface mining *** results indicate that the artificial neural network modelling can accurately predict haul truck fuel consumption based on the values of the haulage parameters considered in this study.

关键词： Fuel consumption Haul truck Surface mine Artificial neural network

Fracture analyses of different pre-holed concrete specimens under compression

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2015年第6期31卷 855-870页

作者： Hadi Haeri Alireza Khaloo Mohammad Fatehi Marji department of Civil engineering Sharif University of Technology Member of National Elites Foundation center of Excellence in Structure and Earthquake engineering Sharif University of Technology Mine Exploitation engineering department Faculty of Mining and Metallurgy Yazd University

Crack propagation processes in specially prepared concrete discs and rectangular specimens containing a single cylindrical hole or multiple holes of varying diameters have been studied both experimentally and numerically. In this research, the cracks coalescence paths in Brazilian disc and rectangular specimens made from rock-like material containing multi-holes are investigated. These concrete specimens are specially prepared from an appropriate mixture of Portland Pozzolana Cement （PPC）, fine sands, and water. The pre-holed Brazilian discs and rectangular specimens are experimentally tested under compression. The breakage load in the ring type disc specimens containing an axial hole with varying diameters is measured and the distribution of the induced lateral stress is obtained. The mechanism of cracks propagation in the wall of the ring type specimens is also stud- ied. In the case of multi-hole Brazilian disc and rectangular specimens, the cracks propagation and cracks coalescence are also investigated. These experiments are numerically modeled by a modified higher order displacement discontinuity method. It has been shown that the corresponding experimental and numerical results are in good agreement with each other. The results presented in this research vali date the accuracy and applicability of these crack analyses procedures.

关键词： Concrete rings Pre-holed Brazilian disc ·Rectangular specimens Crack analyses Coalescence ·Induced lateral stress

Manufacturable Novel Nanogrease with Superb Physical Properties

在线全文

学校读者我要写书评

暂无评论

Nanomanufacturing and Metrology 2021年第4期4卷 289-297页

作者： Hammad Younes Ding Lou Haiping Hong Huahui Chen Hongtao Liu Yinhuai Qiang department of electrical engineering South Dakota School of Mines and TechnologyRapid CitySD 57701USA department of Material Science and engineering School of Mechanical and Electrical EngineeringChina University of Mining and TechnologyBeijing 100083China School of Material Science and engineering China University of Mining and TechnologyXuzhou 221166China

High-performance nanogrease manufactured from carbon nanomaterials is observed to be stable and homogeneous and have superb physical properties,such as thermal and electrical conductivities,compared with current commercial greases made of lithium,calcium,and *** the first time,carbon nanomaterials have been observed to disperse well as the sole thickeners in oil systems,e.g.,polyalphaolefin and polyester(ROYCO),without the aid of any chemical ***-dimensional percolation network structures that exist among carbon nanomaterials are easily scalable,which can be attributed to the intermolecular van der Waals ***,the introduction of hydrogen bonding in any form to grease significantly increases its thermal and electrical conductivities and substantially reduces the weight percentage of carbon nanomaterials needed to fabricate stable *** example,loading of only 1.4 wt%hydroxyl-functionalized multiwalled carbon nanotube(MWNT-OH)with Krytox XHT750 oil leads to a 37.8%increase in thermal ***,75%glycerol,25% water,and 4.5 wt% MWNT-OH yielded the lowest electrical resistivity of 10.0 Ω *** finding can be extended to hydrogen bonding materials with functional groups,such as OH,COOH,F,and *** nanogrease reported in this study has been manufactured using the three-roll mill method,which is an easy and cost-effective method,as the loading weight percentage of carbon nanomaterials to fabricate stable grease decreases from 12 wt% to 3-4 wt%.Furthermore,the process is easily scalable,reproduced,and *** novel high-performance nanogrease has a high commercial value and numerous applications and could replace current commercial greases.

关键词： Nanogrease Three-dimensional network percolation structure Carbon nanomaterial Van der Waals forces Hydrogen bonding Thermal conductivity electrical conductivity

Cracks coalescence mechanism and cracks propagation paths in rock-like specimens containing pre-existing random cracks under compression

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

Journal of Central South University 2014年第6期21卷 2404-2414页

作者： Hadi Haeri Kourosh Shahriar Mohammad Fatehi Marji Parviz Moarefvand department of mining engineering Science and Research BranchIslamic Azad University department of mining and Metallurgical engineering Amirkabir University of Technology Mine Exploitation engineering department Faculty of Mining and MetallurgyInstitution of EngineeringYazd University

The mechanism of cracks propagation and cracks coalescence due to compressive loading of the brittle substances containing pre-existing cracks （flaws） was modeled experimentally using specially made rock-like specimens from Portland Pozzolana Cement （PPC）. The breakage process of the specimens was studied by inserting single and double flaws with different inclination angles at the center and applying uniaxial compressive stress at both ends of the specimen. The first crack was oriented at 50＆#176; from the horizontal direction and kept constant throughout the analysis while the orientation of the second crack was changed. It is experimentally observed that the wing cracks are produced at the first stage of loading and start their propagation toward the direction of uniaxial compressive loading. The secondary cracks may also be produced in form of quasi-coplanar and/or oblique cracks in a stable manner. The secondary cracks may eventually continue their propagation in the direction of maximum principle stress. These experimental works were also simulated numerically by a modified higher order displacement discontinuity method and the cracks propagation and cracks coalescence were studied based on Mode I and Mode II stress intensity factors （SIFs）. It is concluded that the wing cracks initiation stresses for the specimens change from 11.3 to 14.1 MPain the case of numerical simulations and from 7.3 to 13.8 MPa in the case of experimental works. It is observed that cracks coalescence stresses change from 21.8 to 25.3 MPa and from 19.5 to 21.8 MPa in the numerical and experimental analyses, respectively. Comparing some of the numerical and experimental results with those recently cited in the literature validates the results obtained by the proposed study. Finally, a numerical simulation was accomplished to study the effect of confining pressure on the crack propagation process, showing that the SIFs increase and the crack initiation angles change in this case.

关键词： crack propagation crack coalescence rock-like specimen numerical simulation experiment

Recovery and grade prediction of pilot plant flotation column concentrate by a hybrid neural genetic algorithm

在线全文

学校读者我要写书评

暂无评论

International Journal of mining Science and technology 2013年第1期23卷 69-77页

作者： F. Nakhaei M.R. Mosavi A. Sam department of mining engineering Shahid Bahonar Kerman University Kerman Iran department of electrical engineering Iran University of Science and Technology Tehran Iran

Today flotation column has become an acceptable means of froth flotation for a fairly broad range of applications, in particular the cleaning of sulfides. Even after having been used for several years in mineral processing plants, the full potential of the flotation column process is still not fully exploited. There is no prediction of process performance for the complete use of available control capabilities. The on-line estimation of grade usually requires a significant amount of work in maintenance and calibration of on-stream analyzers, in order to maintain good accuracy and high availability. These difficulties and the high cost of investment and maintenance of these devices have encouraged the approach of prediction of metal grade and recovery. In this paper, a new approach has been proposed for metallurgical performance prediction in flotation columns using Artificial Neural Network (ANN). Despite of the wide range of applications and flexibility of NNs, there is still no general framework or procedure through which the appropriate network for a specific task can be designed. Design and structural optimization of NNs is still strongly dependent upon the designer's experience. To mitigate this problem, a new method for the auto-design of NNs was used, based on Genetic Algorithm (GA). The new proposed method was evaluated by a case study in pilot plant flotation column at Sarcheshmeh copper plant. The chemical reagents dosage, froth height, air, wash water flow rates, gas holdup, Cu grade in the rougher feed, flotation column feed, column tail and final concentrate streams were used to the simulation by GANN. In this work, multi-layer NNs with Back Propagation (BP) algorithm with 8-17-10-2 and 8- 13-6-2 arrangements have been applied to predict the Cu and Mo grades and recoveries, respectively. The correlation coefficient (R) values for the testing sets for Cu and Mo grades were 0.93, 0.94 and for their recoveries were 0.93, 0.92, respectively. The results disc

关键词： Artificial neural network Genetic algorithm Flotation column Grade Recovery Prediction

Depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 335-345页

作者： Feng Zhang Chenyang Zhang Linlin Wu Wei Sun Hongliang Zhang Jianhua Chen Yong Pei Songjiang Li engineering Research center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral ResourcesSchool of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China State Key Laboratory of Mineral Processing Beijing General Research Institute of Mining&MetallurgyBeijing 100160China Hunan Provincial Key Laboratory of Micro&Nano Materials Interfaces Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China School of Resources Environment and MaterialsGuangxi UniversityNanning 530004China department of Chemistry Xiangtan UniversityXiangtan 411105China China Railway Resource Group Co.Ltd Beijing 102300China

The depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth ***,the depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory(DFT)*** X-ray photoelectric spectroscopy(XPS)results,DFT calculation results,and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface,suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption ***,the oxygen content in the surface of sphalerite treated with sulfite ions in creased,which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and ***,sulfite ions were chelated with lead ions to form PbSO_(3)in *** hydrophilic PbSO_(3)was more easily adsorbed on sphalerite than *** interaction between sulfite ions and lead ions could effectively inhibit the activation of *** addition the UV spectrum showed that after adding sulfite ions,the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution,indicating that xanthate interacted more readily with sulfite ions and oxygen mo lecules within the sphalerite system,leading to the formation of ***,sulfite ions hardly depressed the flotation of ga lena and could promote the flotation of galena to some *** study deepened the understanding of the depression mechanism o sulfite ions on sphalerite and Pb^(2+)activated sphalerite.

关键词： sphalerite galena sulfite ion density functional theory depression mechanism