检索结果-南通市图书馆

A novel method for modeling the phase change of iron ore particles in the cohesive zone of a blast furnace

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 252-261页

作者： Dianyu e Yingming Wen Jiayun Dan Youyuan jiang Guangchao Wei Jiaxin Cui jiangxi Provincial Key Laboratory for simulation and Modelling of Particulate systems Jiangxi University of Science and TechnologyNanchang330013China International Institute for Innovation Jiangxi University of Science and TechnologyNanchang330013China Ironmaking Plant Xiangtan Iron and Steel Corporation of Hunan HualingXiangtan411101China schoolof Transportation and Vehicle enginering Shandong University of TechnologyZibo255000China

Cohesive zone plays a vital role in the stable operation of a blast furnace(BF),yet the complex phase change process of iron ore particles in this zone is still not well *** this study,a novel one-dimensional(1D)unsteady phase change model was developed to elucidate the heat transfer and melting mechanisms of iron ore *** model validation,the effects of several key operating parameters(e.g.,particle diameter,gas velocity,initial temperature)on the phase change behavior of iron ore particles were analyzed,and the joint effect of multiple parameters was *** results show that larger-sized iron ore particles possess lower specific surface areas,which in turn reduces their convective heat absorption ***,the distance from the solid-liquid phase interface to the particle surface increases,thereby slowing down the movement of the phase interface and pro-longing the melting duration of the *** the gas velocity and the initial temperature does not have a significant impact on reducing the duration of the complete melting *** the specified conditions,it is observed that increasing the gas velocity by 3-fold and 9-fold results in a reduction of the melting duration by 2.4%and 8.3%,*** the initial temperature of iron ore particles results in a decrease in the core-to-surface temperature difference,a slower heating rate,and a shorter duration to achieve *** the factors affecting the melting process,the particle diameter is found to be the most significant in terms of the liquid phase precipitation,mushy zone thickness,and core-to-surface temperature difference of iron ore particles.

关键词： Blast furnace Iron ore melting Cohesive zone Heat transfer Phase change

Descriptors-based machine-learning prediction of cetane number using quantitative structure–property relationship

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

energy and AI 2024年第3期17卷 168-178页

作者： Rodolfo s.M.Freitas Xi jiang school of engineering and Materials science Queen Mary University of LondonMile End RoadLondonE14NSUK

The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.

关键词： Chemical descriptors Quantitative structure-property relationship Machine learning Cetane number Fuel design

enhancement of the surface emission at the fundamental frequency and the transmitted high-order harmonics by pre-structured targets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Power Laser science and engineering 2019年第2期7卷 111-119页

作者： K.Q.Pan D.Yang L.Guo Z.C.Li s.W.Li C.Y.Zheng s.e.jiang B.H.Zhang X.T.He Laser Fusion Research Center China Academy cf Engineering PhysicsMianyang 621900.China Center for Applied Physics and Technology Peking UniversityBeijing 100871China Institute of Applied Physics and Computational Mathematics Beijing 100088China

Laser interaction with an ultra-thin pre-structured target is investigated with the help of both two-dimensional and threedimensional particle-in-cell *** the existence of aperiodic structure on the target surface,the laser seems to penetrate through the target at its fundamental frequency even if the plasma density of the target is much higher than the laser’s relativistically critical *** particle-in-cell simulations show that the transmitted laser energy behind the pre-structured target is increased by about two orders of magnitude compared to that behind the flat *** analyses show that the transmitted energy behind the pre-structured target is actually re-emitted by electron’islands’ formed by the surface plasma waves on the target *** other words,the radiation with the fundamental frequency is actually’surface emission,on the target rear *** the intensity of the component with the fundamental frequency,the intensity of the high-order harmonics behind the pre-structured target is also much enhanced compared to that behind the flat *** enhancement of the high-order harmonics is also related to the surface plasma waves generated on the target surfaces.

关键词： high-order harmonics generation high power laser laser-plasma interaction particle-in-cell simulation

Investigation and optimization of high-valent Ta-doped srFeO_(3-δ)as air electrode for intermediate-temperature solid oxide fuel cells

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2102-2109页

作者： shanshan jiang Hao Qiu shaohua Xu Xiaomin Xu Jingjing jiang Beibei Xiao Paulo sérgio Barros Juliao) Chao su Daifen Chen Wei Zhou school of energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China WA school of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerth WA6102Australia Institute of Analysis and Testing Beijing Academy of Science and TechnologyBeijing 100089China state Key Laboratory of Materials-Oriented Chemical engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China

To explore highly active and thermomechanical stable air electrodes for intermediate-temperature solid oxide fuel cells(ITsOFCs),10mol%Ta5+doped in the B site of strontium ferrite perovskite oxide(srTa_(0.1)Fe_(0.9)O_(3-δ),sTF)is investigated and *** effects of Ta^(5+)doping on structure,transition metal reduction,oxygen nonstoichiometry,thermal expansion,and electrical performance are evaluated *** 10mol%Ta^(5+)doping,the thermal expansion coefficient(TeC)decreased from 34.1×10^(-6)(srFeO_(3-δ))to 14.6×10^(-6) K^(-1)(sTF),which is near the TeC of electrolyte(13.3×10^(-6) K^(-1) for sm_(0.2)Ce_(0.8)O_(1.9),sDC),indicates excellent thermomechanical *** 550-750℃,sTF shows superior oxygen vacancy concentrations(0.262 to 0.331),which is critical in the oxygen-reduction reaction(ORR).Oxygen temperature-programmed desorption(O_(2)-TPD)indicated the thermal reduction onset temperature of iron ion is around 420℃,which matched well with the inflection points on the thermos-gravimetric analysis and electrical conductivity *** 600℃,the sTF electrode shows area-specific resistance(AsR)of 0.152Ω·cm^(2) and peak power density(PPD)of 749 mW·cm^(-2).ORR activity of sTF was further improved by introducing 30wt%sm_(0.2)Ce_(0.8)O_(1.9)(sDC)powder,sTF+sDC composite cathode achieving outstanding AsR value of 0.115Ω·cm2 at 600℃,even comparable with benchmark cobalt-containing cathode,Ba_(0.5)sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)(BsCF).Distribution of relaxation time(DRT)analysis revealed that the oxygen surface exchange and bulk diffusion were improved by forming a composite *** 650℃,sTF+sDC composite cathode achieving an outstanding PPD of 1117 mW·cm^(-2).The excellent results suggest that sTF and sTF+sDC are promising air electrodes for IT-sOFCs.

关键词： strontium ferrite-based perovskite Ta doping composite cathode intermediate-temperature solid oxide fuel cells

Heat Transfer and Friction Characteristics of Printed Circuit Heat exchangers with Different Channel structures for s-CO_(2) Power system

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal science 2024年第3期33卷 1132-1147页

作者： jiang Tao LI Mingjia Key Laboratory of Thermo-Fluid science and engineering of Ministry of education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China school of Mechanical engineering Beijing Institute of TechnologyBeijing100081China

Printed circuit heat exchanger(PCHe)has been widely used in supercritical carbon dioxide(s-CO_(2))power systems because of its high heat transfer efficiency and good ***,due to the large variety of PCHe configurations,channel selection in practical applications lacks a ***,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHe ***,the comprehensive performance of four channels was ***,the heat transfer and friction factor correlations for s-CO_(2)in four channels were *** findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHe is better(β≈180°),so its resistance loss is relatively *** zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat *** sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded *** streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance *** the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHe is 7.0%,which shows good fitting *** research in this paper can provide a reference for the selection and design of PCHe with different channel configurations.

关键词： printed circuit heat exchanger supercritical carbon dioxide typical channel structure field synergy analysis

An improved initial rotor position estimation method using high-frequency pulsating voltage injection for PMsM

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 19-29页

作者： Yang jiang Ming Cheng school of electrical engineering Southeast UniversityNanjing 210096China

High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous ***,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic *** order to solve these problems,a new signal demodulation method is proposed in this *** proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter *** addition,a new magnetic polarity detection method is proposed,which is robust to current measurement ***,experiments verify the effectiveness of the method.

关键词： Initial position detection signal demodulation algorithm Magnetic polarity detection Filter elimination

Tribological evaluation of thermoplastic polyurethane-based bearing materials under water lubrication:effect of load,sliding speed,and temperature

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第8期12卷 1801-1815页

作者： shaoli jiang Janet ssWONG Debashis PUHAN Tian YUAN Xiuqin BAI Chengqing YUAN state Key Laboratory of Maritime Technology and safety Wuhan University of TechnologyWuhan 430063China Department of Mechanical engineering Imperial College LondonLondon SW72AZUK Yusuf Hamied Department of Chemistry University of CambridgeLensfield RoadCambridge CB21EWUK

Polymers are widely used in bearing *** the case of water-lubricated stern tube bearings,thermoplastic polyurethane(TPU)-based composites are used due to their excellent wear resistance,corrosion resistance,and tunable mechanical *** tribological performance,however,depends on operating *** this work,TPU was blended with carbon fiber,graphene platelet,and ultra-high molecular weight polyethylene(UHMWPe).Friction tests of TPU based-composites against copper countersurface were carried out in water to mimic the actual operating conditions of the *** of the resulting contacts were in the boundary lubrication regime,in which friction was attributed to both contact mechanics of asperities as well as water *** results show that the viscoelasticity of TPU has a considerable impact on its tribological *** lubrication at 50°C promotes the softening of polymer surface material during sliding,resulting in higher fluctuation in the coefficient of friction and wear *** is attributed to the reduced thermomechanical *** addition,schallamach waviness is observed on worn *** tribological properties of TPU are significantly improved by the inclusion of carbon fiber,graphene platelet,and *** formation of graphene transfer-layers and UHMWPe transfer film reduces friction and wear loss,while the inclusion of carbon fiber enhances wear resistance due to improved mechanical properties and load bearing capacity.

关键词： friction thermoplastic polyurethane(TPU) water-lubricated bearings graphene platelet carbon fibers ultra-high molecular weight polyethylene(UHMWPe)

Co/CoO heterojunction rich in oxygen vacancies introduced by O2 plasma embedded in mesoporous walls of carbon nanoboxes covered with carbon nanotubes for rechargeable zinc-air battery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon energy 2024年第7期6卷 14-25页

作者： Leijun Ye Weiheng Chen Zhong-Jie jiang Zhongqing jiang Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhouChina Department of Mechanical engineering Ningbo University of TechnologyNingboChina Guangzhou Key Laboratory for surface Chemistry of energy Materials Guangdong Engineering and Technology Research Center for Surface Chemistry of Energy MaterialsCollege of Environment and EnergySouth China University of TechnologyGuangzhouChina

Herein,Co/CoO heterojunction nanoparticles(NPs)rich in oxygen vacancies embedded in mesoporous walls of nitrogen-doped hollow carbon nanoboxes coupled with nitrogen-doped carbon nanotubes(P-Co/CoOV@NHCNB@NCNT)are well designed through zeolite-imidazole framework(ZIF-67)carbonization,chemical vapor deposition,and O_(2) plasma *** a result,the threedimensional NHCNBs coupled with NCNTs and unique heterojunction with rich oxygen vacancies reduce the charge transport resistance and accelerate the catalytic reaction rate of the P-Co/CoOV@NHCNB@NCNT,and they display exceedingly good electrocatalytic performance for oxygen reduction reaction(ORR,halfwave potential[eORR,1/2=0.855 V *** hydrogen electrode])and oxygen evolution reaction(OeR,overpotential(η_(OeR,10)=377mV@10mA cm^(−2)),which exceeds that of the commercial Pt/C+RuO_(2) and most of the formerly reported ***,both the aqueous and flexible foldable all-solid-state rechargeable zinc-air batteries(ZABs)assembled with the P-Co/CoOV@NHCNB@NCNT catalyst reveal a large maximum power density and outstanding long-term cycling ***-principles density functional theory calculations show that the formation of heterojunctions and oxygen vacancies enhances conductivity,reduces reaction energy barriers,and accelerates reaction kinetics *** work opens up a new avenue for the facile construction of highly active,structurally stable,and cost-effective bifunctional catalysts for ZABs.

关键词： heterojunction oxygen evolution/reduction reaction oxygen vacancies rechargeable zinc–air battery three‐dimensional nitrogen‐doped hollow carbon nanoboxes

Hybrid rogue waves and breather solutions on the double-periodic background for the Kundu-DNLs equation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第5期76卷 33-48页

作者： DongZhu jiang Zhaqilao College of Mathematics science Inner Mongolia Normal UniversityHohhot 01022China Center for Applied Mathematical science Inner MongoliaHohhot 010022China

In this paper,by using the Darboux transformation(DT)method and the Taylor expansion method,a new nth-order determinant of the hybrid rogue waves and breathers solution on the double-periodic background of the Kundu-DNLs equation is constructed when n is *** and rogue waves can be obtained from this determinant,*** to this,the hybrid rogue waves and breathers solutions on the different periodic backgrounds are given explicitly,including the single-periodic background,the double-periodic background and the plane wave background by selecting different *** addition,the form of the obtained solutions is summarized.

关键词： double-periodic background hybrid rogue waves and breather darboux transformation Kundu-DNLs equation