检索结果-南通市图书馆

Influence of in situ formed spinel in bonding phase on mechanical properties and air permeability of magnesia-chrome porous purging materials

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

Journal of Iron and Steel Research International 2024年第6期31卷 1459-1472页

作者： Yi An Hao Liu Zhou-fu Wang Yan Ma xi-tang Wang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Magnesia-chrome porous purging plugs are crucial functional components to remove inclusions and stabilize the flow field during iron and steel ***,practical applications of magnesia-chrome porous purging materials are stil hampered by the poor scouring resistance to molten steel and unstable air permeability owing to their low mechanical properties and uncontrollable pore ***,the particle-packing type magnesiachrome porous purging materials reinforced by in situ formed spinel were prepared using fused magnesia-chrome particles and Al powders as major raw *** results show that in situ formed spinel solid solutions in bonding phase led to the decreased median pore size and increased pore surface fractal dimension from the reactions between Al powders and magnesia-chrome particles and along with high-temperature sintering,bonding between magnesia-chrome particles and the resultant mechanical properties of materials were greatly ***,the results of air permeability tests and polynomial ftting indicated that the formation of spinel solid solutions was the main contributing factor for controllable air permeability,and pressure drop of porous purging materials was positively correlated with surface fractal dimension of ***,the as-prepared porous purging materials added with 6 wt.%Al powders obtained the maximum cold crushing strength(54.2 MPa)and hot modulus of rupture(12.9 MPa)with median pore size of 24.06μm and ftting non-Darcian permeability coefficient of 0.97×10^(-6)m.

关键词： Magnesia Chrome porous purging material Metallic Al-Spinel Mechanical strength Air permeability

Effects of hot deformation and in-situ ZrB2 particle on microstructure and tensile performance of AA7085 composite sheets

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 Iron and Steel Research International 2024年第7期31卷 1778-1791页

作者： Jiang-jing Wu xi-zhou Kai Chuang Guan Yu-tao Zhao school of Material science and engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

To provide a new idea to reduce anisotropy for sheets in the thickness direction by microstructure modification and,mean-while,maintain or even enhance tensile performance,the in-situ ZrB2 particle/AA7085 composite sheets with thicknesses of 1,2,3,and 6 mm were *** as-cast grain size was significantly refined by the heterogeneous nucleus of the ZrB2 *** microstructure results show that severe hot deformation converts as-cast disordered microstructure into a sequential microstructure by crushing the remanent phases and matrix into a fiber *** the solid solution and aging heat treatment,the composite sheets exhibit largely recrystallized grains compared with partially recrystallized grains in the matrix sheets,and weak or even free texture exists in the *** grain size in the composite sheets decreases with the increase in thickness *** the thickness range of 1-3 mm,the composite sheets maintain a similar tensile per-formance as that in matrix sheets,while the strength and ductility in the 6-mm-thick composite sheet are improved.

关键词： Composite sheet Grain structure Texture Dislocation Strengthening

A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第2期10卷 282-291页

作者： Jiachen Yang Meng xi Jiabao Wen Yang Li Houbing Herbert Song school of Electrical and Information engineering Tianjin UniversityTianjin300072China Security and Optimization for Networked Globe Laboratory(SONG Lab) Embry-Riddle Aeronautical UniversityDaytona BeachFL32114USA

The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential *** to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal *** traditional models mainly utilize mathematical functions,which are not complete and *** existing path planning algorithms depend on the environment and lack *** overcome these challenges,we propose a path planning system for underwater intelligent internet *** applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path *** design a value-based reinforcement learning path planning algorithm and explore the optimal network structure *** path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge *** integration of state input enriches the learning of neural networks and helps to improve generalization and *** task-related reward function promotes the rapid convergence of the *** experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions.

关键词： Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning

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

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

Unlocking the potential of transdermal drug delivery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Smart and Nano materials 2024年第3期15卷 432-468页

作者： Shuang Li Jianhao Wu xiangjun Peng xi-Qiao Feng Institute of Biomechanics and Medical engineering Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijingChina

Transdermal drug delivery(TDD)has gained clinical approval over several decades,with extensive research dedicated to novel drug and device *** notable research progress,the mar-ket adoption of TDD devices has not met anticipated levels,with oral administration and injection remaining predominant delivery *** maximize the potential of TDD,we identify bottlenecks hinder-ing its widespread clinical application and propose promising research *** begin by analyzing stringent demands necessary to truly benefit patients,addressing significant challenges in biomechanics,nanomedicine,and flexible ***,we delve into skin anatomy,enhancement strategies,nano-carriers,and their under-lining mechanisms,highlighting the importance and framework of quantitative *** on these discussions,we highlight the core strength of TDD,such as automatic precise administration based on feedback and high delivery efficiencies,especially applicable to localized conditions(e.g.,central nervous system diseases,tumors).Finally,we envision the future of intelligent TDD device and its opera-tion scenario,aiming to steer research efforts toward faster translation of laboratory innovations into widely used products for sufferers.

关键词： Transdermal drug delivery biomechanics nanomedicine flexible electronics

Coupled Cross-Flow/in-Line Vortex-Induced Vibration Responses of a Catenary-Type Riser Subjected to Uniform Flows

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 Ocean university of china 2024年第5期23卷 1202-1212页

作者： LI xiaomin CAO xi LI Fuheng YANG Zhiwen College of engineering Ocean University of ChinaQingdao 266404China College of Hydrodynamic engineering Tianjin Research Institute for Water Transport EngineeringM.O.TTianjin 300456China

A three-dimensional numerical scheme was developed to investigate the vortex-induced vibration(VIV)of a catenary-type riser(CTR)in the in-line(IL)and cross-flow(CF)*** using the vector form intrinsic finite element method,the CTR was discretized into a finite number of spatial particles whose motions satisfy Newton’s second *** Van der Pol oscillator was used to simulate the effect of vortex *** coupling equations of structural vibration and wake oscillator were solved using an explicit central differential *** numerical model was verified with the published *** VIV characteristics of the CTR subjected to uniform flows,including displacement,frequency,standing wave,traveling wave,motion trajectory,and energy transfer,were studied *** numerical results revealed that the multimode property occurs in the CF-and IL-direction VIV responses of the *** increase in the flow velocity has slight effects on the maximum VIV *** to structural nonlin-earity,the double-frequency relationship in the CF and IL directions is rarely ***,the vibration trajectories display the shape of an inclined elliptical ***,the negative energy region is inconspicuous under the excitation of the uniform flow.

关键词： vortex-induced vibration vector form intrinsic finite element catenary-type riser wake oscillator equation

Thermal stability of nanocrystalline W-Ti diffusion barrier thin films

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

science china(Technological sciences) 2010年第4期53卷 1049-1055页

作者： WANG Qingxiang,FAN ZhiKang & LIANG ShuHua school of materials science and engineering,xi’an university of technology,xi’an 710048,china 1. school of materials science and engineering Xi’an University of Technology Xi’an 710048 China

Nanocrystalline W-Ti diffusion barrier thin films with different phase structures and Cu/barrier/Si multilayer structures were deposited on p-type Si(100) substrates by DC magnetron *** films were annealed at different temperatures for 1 *** diffusion barrier properties and thermal stability were studied using four-probe tester(FPP),XRD,AFM,XPS,FESEM,and *** experimental results showed that the films were stable up to 700℃.When the annealing temperature was increased,the Cu and Ti atoms began to react and CuTi3 was *** addition,the high resistance Cu3Si was formed due to inter-diffusion between the Si and Cu atoms which made the surface rougher and caused the sheet resistance to increase *** the same time,failure mechanism of the nanocrystalline W-Ti diffusion barrier thin films during annealing process was also discussed.

关键词： nanocrystalline W-Ti thin films diffusion barrier anneal sheet resistance

Heterostructure of 2D MoSe_(2) nanosheets vertically grown on bowllike carbon for high-performance sodium storage

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

Nano Research 2024年第5期17卷 4023-4030页

作者： Nianxiang Shi Guangzeng Liu Baojuan xi Xuguang An Changhui Sun Shenglin xiong school of Chemistry and Chemistry engineering Qilu Normal UniversityJinan 250200China school of Chemistry and Chemical engineering Shandong UniversityJinan 250100China school of Mechanical engineering Chengdu UniversityChengdu 610106China

Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer ***,its practical application is hampered by the sluggish kinetics of Na^(+)insertion and structure collapse caused by Na^(+)insertion/***,the heterostructures of MoSe_(2) nanosheets vertically growing on bowl-like carbon(MoSe_(2)@C)are designed and prepared by a template method coupled with selenization treatment to boost storage sodium *** hollow and collapse could provide enough storage space for Na^(+)and alleviate the volume expansion during the charge/discharge ***_(2) nanosheets vertically grown on carbon could expose more active sites for adsorbing Na^(+)to enhance the utilization rate of electrode ***,building heterostructures by combining different phase components could facilitate Na^(+)diffusion and advance reaction *** from these merits,the bowl-like MoSe_(2)@C shows outstanding reversible capacity(356.8 mAh·g^(-1) after 1500 cycles at 1 A·g^(-1))and remarkable rate performance(249.9 mAh·g^(-1)10 A·g^(-1)).

关键词： MoSe_(2)nanosheets bowl-like carbon heterostructure sodium ion batteries

An Accelerated Proximal Gradient Algorithm for Hankel Tensor Completion

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 the Operations Research Society of china 2024年第2期12卷 461-477页

作者： Chuan-Long Wang xiong-Wei Guo xi-Hong Yan Key Laboratory of engineering and Computational science Shanxi Provincial Department of EducationJinzhong 030619ShanxiChina Department of Mathematics Taiyuan Normal UniversityJinzhong 030619ShanxiChina

In this paper,an accelerated proximal gradient algorithm is proposed for Hankel tensor completion *** our method,the iterative completion tensors generated by the new algorithm keep Hankel structure based on projection on the Hankel tensor ***,due to the special properties of Hankel structure,using the fast singular value thresholding operator of the mode-s unfolding of a Hankel tensor can decrease the computational ***,the convergence of the new algorithm is discussed under some reasonable ***,the numerical experiments show the effectiveness of the proposed algorithm.

关键词： Hankel tensor Tensor completion Accelerated proximal gradient algorithm