检索结果-南通市图书馆

Structural Durability & Health Monitoring 2025年第1期19卷 55-75页

作者： Zhenyu Zhang Quan Jin Haitao Zhang Zhao Liu Yuyang Wu Longfei Zhang Renzhang Yan CCCC Third Highway engineering co. Ltd.Beijing101300China School of Civil engineering Chongqing Jiaotong UniversityChongqing400074China

When the upper chord beam of the beam-string structure(BSS)is made of co.crete-filled steel tube(CFST),its overall stiffness will change greatly with the co.struction of co.crete placement,which will have an impact on the design of the tensioning plans and selection of co.trol measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of co.posite BSS during co.struction,the influence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of co.crete,and friction co.fficient on the bending stiffness are analyzed parametrically by the numerical simulation technology based on an actual *** calculation formula of the equivalent bending stiffness of CFST is also established through mathematical statistical ***,the equivalent bending stiffness is introduced into the co.struction and use stages of the co.posite BSS,respectively,and the mechanical properties such as prestress-tensioning co.trol value,structural deformation,and internal force of key members are co.paratively analyzed when adopting two different co.struction ***,the optimal co.struction plan of co.crete placement first and then prestress-tensioning is proposed.

关键词： co.crete panels freeze-thaw damage co.pression-shear crack tension-shear crack

Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

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 Energy Chemistry 2025年第1期100卷 730-738页

作者： Peng Zheng Wang Zhou Ying Mo Biao Zheng Miaomiao Han Qin Zhong Wenwen Yang Peng Gao Lezhi Yang Jilei Liu co.lege of Materials Science and engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Greater Bay Area Institute for Innovation Hunan University Changsha Research Institute of Mining & Metallurgy co. LTD.

Hard carbon （HC） has been co.sidered as promising anode material for sodium-ion batteries （SIBs）.The optimization of hard carbon’s microstructure and solid electrolyte interface （SEI） property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly ***,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage ***-situ Fourier transform infrared spectrosco.y/electrochemical impedance spectrosco.y （FTIR/EIS） and X-ray photoelectron spectrosco.y （XPS） analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate *** a result,the hard carbon anode with optimized boron doping co.tent exhibits enhanced rate and cycling *** general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.

关键词： X ray photoelectron spectrosco.y

Nano-Enhanced Dairy Scum Biodiesel Blends:Unleashing the Power of Aluminium Oxide for Sustainable and Efficient Engine Performance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期 283-302页

作者： Veeranna MODI Prasad B.RAMPURE Sunil Kumar SHETTY Madeva NAGARAL Channa Keshava NAIK N Johar MGM Muhammad Irsyad ABDULLAH Abdullah I.AL-MANSOUR Shamshad ALAM KLE co.lege of engineering and Technology ChikodiVisvesvaraya Technological University Nitte (Deemed to be University) NMAM Institute of Technology (NMAMIT)Department of Mechanical Engineering Aircraft Research and design Centre HAL Department of Mechanical engineering BGS College of Engineering and TechnologyBengaluruAffiliated to Visvesvaraya Technological University Management and Science University Department of Civil engineering College of EngineeringKing Saud University

This study investigates the effect of aluminium oxide nanoparticlesaddition to biodiesel blends made from dairy milk scum on performance and co.bustion characteristics of the diesel *** dispersion of Al2O3nanoparticles in B20 blends at different co.centrations was done with the help of *** number of blends were prepared for the *** Machine learning algorithms(Random Forest（RF）and CatBoost) was used for the *** results show that in co.parison to biodiesel blends without nanoparticles,the kinematic visco.ity and density is higher for fuel blends with *** these Fuel blends have higher calorific *** blends exhibited reduced Brake Specific Fuel co.sumption（BSFC） of2.85% than the blends without nano particles(Dairy Scum Methyl Ester Biodiesel 20%+Neat Diesel 80%（in volume）,DSMEB20),57.14% less co.40.8% less hydrocarbon,and increased NOxemissions co.pared to co.ventional diesel,co.tributing to the development of environmentally friendly and renewable biofuel blends with *** B20NP30 is the optimal blend for performance and emission *** study co.cludes with findings on enhanced Brake Thermal Efficiency（BTE） of 26.29% in 3×10-5（in volume） Al2O3nanoparticle-blended DSME B20 and other DSME B20 fuel blends,emphasizing the importance of optimal nanoparticle *** co.relation matrix shows how engine load,efficiency measures（BTE,BSFC）,and emissions（co.co.,NOx,Smoke） are co.nected in co.plex *** results help us understand the co.plicated dynamics of engine performance and emission characteristics ***'s diagram for BTE and BSFC shows that CatBoost-based BTE models perform superior to RF-based models during the training as well as testing *** results were obtained for co.and co.emission results.

关键词：

Modification of Maxwell model for co.ductivity prediction of carbon nanotubes-filled polymer co.posites with tunneling effect

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 25-36页

作者： Jue ZHU Longyuan LI Ningtao ZHU Zhejiang Provincial engineering Research Center for the Safety of Pressure Vessel and Pipeline Key Laboratory of Impact and Safety engineering (Ningbo University) Ministry of Education School of engineering Computing and Mathematics University of Plymouth Xi'an Zhanshi Testing & engineering co.Ltd.

Carbon nanotubes(CNTs) have garnered great attention in recent years due to their outstanding electrical, thermal, and mechanical properties. The inco.poration of small amounts of CNTs in polymers can substantially improve the sensitivity of the polymer's electrical co.ductivity. This paper presents a modified Maxwell model to evaluate the electrical co.ductivity of CNTs-filled polymer co.posites by introducing a transition zone to acco.nt for the tunneling effect. In this modified Maxwell model, the CNTs-filled polymer co.posite is modeled as a three-phase co.posite, co.sisting of a matrix(polymer), inclusions(CNTs), and a transition zone(tunneling zone). The effective electrical co.ductivity(EEC) of the co.posite is calculated based on the volume fractions and electrical co.ductivities of the matrix, inclusions, and transition zone. The model's validity is co.firmed through the use of available test data, which demonstrates its capability to accurately capture the nonlinear co.ductivity behavior observed in CNTs-polymer co.posites. This study offers valuable insights into the design of high-performance co.ductive polymer nanoco.posites, and enhances the understanding of electrical co.duction mechanisms in CNT-dispersed polymer co.posites.

关键词：

Macro-mechanical properties of co.umnar jointed basaltic rock masses

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2011年第6期18卷 2143-2149页

作者：狄圣杰徐卫亚宁宇王伟吴关叶 Institute of Geotechnical engineering Hohai University Kunming Investigation and design Institute China Hydropower Engineering Group Co. East China Investigation and design Institute China Hydropower Engineering Group Co.

From the geological structure of the co.umnar jointed rock mass, a visual model was established in software AUTOCAD by programming based on the algorithm of the Voronoi diagram. Furthermore, a program to co.vert the AUTOCAD model into 3DEC (3-dimensional distinct element co.e) model was developed, and a numerical model was established in 3DEC. Moreover, the results of triaxial co.pression tests of co.umnar jointed rock masses were simulated numerically. The REV (representative element volume) scale was studied, and the result shows that the REV size is 3 m × 3 m. The proposed approach, the established model and the numerical simulation were applied to study the macro-mechanical properties and the equivalent strength parameters of the co.umnar jointed rock mass. The numerical simulation results are in good acco.dance with the in-situ test results.

关键词： co.umnar joint Voronoi diagram three-dimensional distinct element co.e representative element volume mechanicalparameters

Longhole waterjet rotary cutting for in-seam cross panel methane drainage

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2010年第3期20卷 378-383页

作者： LU Tingkan YU Hong DAI Yaohui School of Energy Science and engineering Henan Polytechnic University Jiaozuo 454000 China Zhaogu No.1 co.l Mine Jiaozuo Coal Co. Ltd. Henan Coal and Chemical Industry Group Co. Ltd. Xinxiang 453600 China tongchuang co.l Administration Bureau Tongchuang 710054 China

In order to improve the efficiency of gas drainage before and during longwall extraction,a waterjet rotary cutting system has been developed for in-seam cross panel methane *** purpose of the water rotary cutting system developed was to create artificial fractures along the gas drainage *** the design of the system,it was perceived that the nozzle geometry is one of the key factors,affecting cutting ***,we studied the structural and geometric parameters of the nozzle and optimized its performance during laboratory tests and numerical *** trials co.ducted in a co.l mine,indicate that production of gas drainage before and after cutting significantly increased by up to three *** advantages of waterjet assisted gas drainage method has been identified as:1) increasing gas drainage efficiency,2) a possible development of a gas drainage fractured network within co.l seams associated with panel extraction,and 3) reducing the risk of exceeding gas limits during longwalling.

关键词： gas drainage waterjet rotary cutting longhole longwall

Damage model of fresh co.crete in sulphate environment

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2015年第3期22卷 1104-1113页

作者：张敬书张银华冯立平金德保汪朝成董庆友 Key Laboratory of Mechanics on Disaster and Environment in Western China(Ministry of Education) co.lege of Civil engineering and Mechanics Lanzhou University Gansu Architectural design and Research Institute China Triumph International engineering co. Ltd. Gansu Architecture design &co.sultation co. Ltd. Shanghai Zhongfang Architectural design co. Ltd.

A model of damage to fresh co.crete in a co.rosive sulphate environment was formulated to investigate how and why the strength of co.roded co.crete changes over time. First, a co.roded co.crete block was divided into three regions: an expanded and dense region; a crack-development region; and a nonco.roded region. Seco.d, based on the thickness of the surface co.rosion layer and the rate of loss of co.pressive strength of the co.roding region, a co.putational model of the co.crete blocks' co.rosion-resistance co.fficient of co.pressive strength in a sulphate environment was generated. Third, experimental tests of the co.rosion of co.crete were co.ducted by immersing specimens in a co.rosive medium for 270 d. A co.parison of the experimental results with the co.putational formulae shows that the calculation results and test results are in good agreement. A parameter analysis reveals that the co.rosion reaction plays a major role in the co.rosion of fresh co.crete co.taining ordinary Portland cement,but the diffusion of the co.rosion medium plays a major role in the co.rosion of co.crete mixtures co.taining fly ash and sulphate-resistant cement. Fresh co.crete with a high water-to-cement ratio shows high performance during the whole experiment process whereas fresh co.crete with a low water-to-cement ratio shows poor performance during the late experiment period.

关键词： fresh co.crete sulphate co.rosion co.rosion co.fficient co.putational model

Mineralogical characterization and co.prehensive utilization of micro-fine tantalum–niobium ores from Songzi

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第4期34卷 282-290页

作者： Zhi-Tao Yuan Ji-Wei Lu Hui-Fang Wu Jiong-Tian Liu School of Resources & Civil engineering Northeastern University Department of design Northeastern University Engineering and Research Institute Co. Ltd.

The mineralogical characteristics of tantalumniobium ores from Songzi were investigated using mineral liberation analyzer （MLA） and chemical analysis. In particular, the chemical co.position, phase co.position, particle size, and dissemination characteristics of the ores were studied in detail. Results show that Ta2O5 and Nb2O5 have grades of 0.013 % and 0.011%, respectively. The main valuable minerals in the ores are tantalite, co.- umbite, tantalum-niobite, and microlite, and the gangue minerals associated with tantalum-niobium minerals mainly include quartz, kaolinite, illite, feldspar, and mica among others. The minerals are embedded in a co.plex manner. Tantalum-niobium minerals with most particle sizes of -0.040 mm are disseminated in minerals, such as mica, illite, quartz, and partially intergrown with topaz and zirco., where they co.ld not be easily liberated. Thus, the ores are classified as low-grade, micro-fine, and refractory tantalum-niobium ores. Based on this co.sideration, the process of classification-gravity co.centration-magnetic separation-middlings regrinding and gravity co.centration are finally determined and satisfactory indices are obtained. Two rough co.centrates are produced： co.centrate I has Ta2O5 and Nb2O5 grades of 7.0292 % and 3.546 %, respectively, as well as reco.ery of 49.42 % and 35.46 %. By co.parison, co.centrate Ⅱ has Ta2O5 and Nb2O5 grades of 7.0292 % and 3.546 %, respectively, as well as reco.ery of 49.42 % and 35.46 %.

关键词： Mineralogy Tantalum-niobite co.prehensive utilization Micro-fine particles

Microstructural design in LaCe misch-metal substituted 2:14:1-type sintered magnets by dual-alloy method

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2021年第3期39卷 305-311,I0003页

作者： Kan Chen Shuai Guo Hongliang Zhao Xiaodong Fan Fengchun Fan Guangfei Ding Renjie Chen Xiwen Zheng Aru Yan Key Lab of Magnetic Materials and Devices Ningbo Institute of Macerials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Ningbo tongchuang Strong Magnet Material co. Ltd.Ningbo 315201China

LaCe-based sintered magnets with different microstructural features and distinct rare earth elemental distribution were designed by dual-alloy *** sample prepared by fine LaCe-co.taining powder and co.rse LaCe-free powder possesses higher remanence(~13.41 kGs),whereas another sample prepared by fine LaCe-free powder and co.rse LaCe-co.taining powder possesses higher co.rcivity(~5.67 kOe).Additionally,these samples are with the same nominal co.positions and their elemental distribution features are obviously different in matrix grains *** remanence difference is mainly affected by the saturation magnetization difference caused by the distribution variation of the rare earth elements at the matrix *** co.rcivity difference is affected by the co.ponent of the grain boundary phase between the adjacent grains and the distribution variation of the rare earth elements at the matrix *** findings may provide a new prospect for the utilization of LaCe mischmetal in 2:14:1-type permanent magnets.

关键词： Misch-metal Microstructural design Sintered magnet Rare earths

Dynamic properties analysis of a stay cable-damper system in co.sideration of design and co.struction factors

在线全文

学校读者我要写书评

暂无评论

Earthquake engineering and engineering Vibration 2014年第2期13卷 317-326页

作者： Dan Danhui Chen Yanyang Xiao Rong Department of Bridge engineering Tongji University Henan Provincial co.munications Planning Survey & design Institute co. Ltd

A numerical solution based on the Steffensen stable point iterative method is proposed to resolve the transcendental frequency equation of a stay cable-damper system. The frequency equation, which co.siders clamped supports and fl exural rigidity of the cable, is intended to investigate the infl uence of the parameters of the cable damper system on its dynamic characteristics. Two factors involved in the design and co.struction phases, the damping co.ffi cient induced by external dampers and the cable tension, are the focus of this study. Their impact on modal frequencies and damping ratios in these two phases of cable-damper systems are investigated by resolving the equation with the proposed solution. It is shown that the damping co.ffi cient and cable tension exert more noticeable effects on the modal damping ratios than on the modal frequencies of stay cable-damper systems, and the two factors can serve as design variables in the design phase and as adjustment factors in the co.struction phase. On the basis of the results, a roadmap for system-level optimal design of stay cable-damper systems that can achieve global optimal vibration suppression for the entire bridge is proposed and discussed.

关键词： cable damper damping co.ffi cient cable tension dynamic property optimal design