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A PML Method for Electromagnetic Scattering from Two-dimensional Overfilled Cavities

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Communications in mathematical Research 2009年第1期25卷 53-68页

作者： liu juan ma fu-ming College of mathematics Jilin University Changchun 130012

In this paper, we consider electromagnetic scattering problems for two-dimensional overfilled cavities. A half ringy absorbing perfectly matched layer （PML） is introduced to enclose the cavity, and the PML formulations for both TM and TE polarizations are presented. Existence, uniqueness and convergence of the PML solutions are considered. Numerical experiments demonstrate that the PML method is efficient and accurate for solving cavity scattering problems.

关键词： overfilled cavity scattering TM polarization TE polarization perfectly matched layer (PML) DtN operator

Gyroid Triply Periodic Minimal Surface Lattice Structure Enables Improved Superelasticity of CuAlMn Shape Memory Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1047-1065页

作者： Mengwei Wu Chunmei ma Ruiping liu Huadong fu Department of materials Science and Engineering China University of Mining and Technology(Beijing)Beijing100083China Institute for Advanced materials and Technology University of Science and Technology BeijingBeijing100083China

Improving the shape memory effect and superelasticity of Cu-based shape memory alloys(Smas)has always been a research hotspot in many *** work systematically investigates the effects of Gyroid triply periodic minimal surface(TPMS)lattice structures with different unit sizes and volume fractions on the manufacturing viability,compressive mechanical response,superelasticity and heating recovery properties of CuAlMn *** results show that the increased specific surface area of the lattice structure leads to increased powder adhesion,making the manufacturability proportional to the unit size and volume *** compressive response of the CuAlMn Smas Gyroid TPMS lattice structure is negatively correlated with the unit size and positively correlated with the volume *** superelastic recovery of all CuAlMn Smas with Gyroid TPMS lattice structures is within 5%when the cyclic cumulative strain is set to be 10%.The lattice structure shows the maximum superelasticity when the unit size is 3.00 mm and the volume fraction is 12%,and after heating recovery,the total recovery strain increases as the volume fraction *** study introduces a new strategy to enhance the superelastic properties and expand the applications of CuAlMn Smas in soft robotics,medical equipment,aerospace and other fields.

关键词： Shape memory alloys Superelasticity Gyroid triply periodic minimal surface(TPMS)lattice structure Selective laser melting(SLM)

A general synthetic strategy for N, P co-doped graphene supported metal-rich noble metal phosphides for hydrogen generation

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Green Energy & Environment 2024年第1期9卷 152-162页

作者： Jingwen ma Xiang Li Guangyu Lei Jun Wang juan Wang Jian liu ming Ke Yang Li Chunwen Sun School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Lab of Advanced Nano-structures&Transfer Processes Department of Chemical EngineeringTianjin UniversityTianjin300354China PetroChina Planning and Engineering Institute Beijing100083China

The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a *** have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction ***,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked *** obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 ma cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/*** addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,*** superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the ***,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for *** work provides an effective strategy for designing NMP-based electrocatalysts.

关键词： Noble metal phosphides Electrocatalyst Deoxyribonucleic acid Hydrogen evolution pH universal

machine learning-assisted efficient design of Cu-based shape memory alloy with specific phase transition temperature

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International Journal of Minerals,Metallurgy and materials 2024年第4期31卷 773-785页

作者： Mengwei Wu Wei Yong Cunqin fu Chunmei ma Ruiping liu Department of materials Science and Engineering China University of Mining&Technology(Beijing)Beijing 100083China Institute for Advanced materials and Technology University of Science and Technology BeijingBeijing 100083China

The martensitic transformation temperature is the basis for the application of shape memory alloys(Smas),and the ability to quickly and accurately predict the transformation temperature of Smas has very important practical *** this work,machine learning(ML)methods were utilized to accelerate the search for shape memory alloys with targeted properties(phase transition temperature).A group of component data was selected to design shape memory alloys using reverse design method from numerous unexplored *** modeling and feature modeling were used to predict the phase transition temperature of the shape memory *** experimental results of the shape memory alloys were obtained to verify the effectiveness of the support vector regression(SVR)*** results show that the machine learning model can obtain target materials more efficiently and pertinently,and realize the accurate and rapid design of shape memory alloys with specific target phase transition *** this basis,the relationship between phase transition temperature and material descriptors is analyzed,and it is proved that the key factors affecting the phase transition temperature of shape memory alloys are based on the strength of the bond energy between *** work provides new ideas for the controllable design and performance optimization of Cu-based shape memory alloys.

关键词： machine learning support vector regression shape memory alloys martensitic transformation temperature

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

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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

Fake News Detection Based on Text-Modal Dominance and fusing Multiple Multi-Model Clues

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Computers, materials & Continua 2024年第3期78卷 4399-4416页

作者： Li fang fu Huanxin Peng Changjin ma Yuhan liu College of Arts and Sciences Northeast Agricultural UniversityHarbin150030China College of Engineering Northeast Agricultural UniversityHarbin150030China

In recent years,how to efficiently and accurately identify multi-model fake news has become more ***,multi-model data provides more evidence but not all are equally ***,social structure information has proven to be effective in fake news detection and how to combine it while reducing the noise information is ***,existing approaches fail to handle these *** paper proposes a multi-model fake news detection framework based on Tex-modal Dominance and fusing Multiple Multi-model Cues(TD-MMC),which utilizes three valuable multi-model clues:text-model importance,text-image complementary,and text-image ***-MMC is dominated by textural content and assisted by image information while using social network information to enhance text *** reduce the irrelevant social structure’s information interference,we use a unidirectional cross-modal attention mechanism to selectively learn the social structure’s features.A cross-modal attention mechanism is adopted to obtain text-image cross-modal features while retaining textual features to reduce the loss of important *** addition,TD-MMC employs a new multi-model loss to improve the model’s generalization *** experiments have been conducted on two public real-world English and Chinese datasets,and the results show that our proposed model outperforms the state-of-the-art methods on classification evaluation metrics.

关键词： Fake news detection cross-modal attention mechanism multi-modal fusion social network transfer learning

Ash removal from inferior coal via ammonium fluoride roasting and simultaneous yield of white carbon black

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International Journal of Mining Science and Technology 2024年第2期34卷 261-279页

作者： Xuqin Duan Shuaiyu Lu Yuxiao fu Jiazhe Zhang Tong liu Jian ma School of Civil and Resource Engineering University of Science&Technology BeijingBeijing 100083China State Key Laboratory for Efficient Mining of Metal Mines University of Science&Technology BeijingBeijing 100083China China Coal Processing and Utilizaiton Association Beijing 100013China

The quality upgrading and deashing of inferior coal by chemical method still faces great *** dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial *** paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting *** the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,*** molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and *** majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia *** of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via *** research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously.

关键词： Inferior coal Deashing treatment Silicon recycling Ammonium fluoride roasting White carbon black

Incorporating Lasso Regression to Physics-Informed Neural Network for Inverse PDE Problem

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 385-399页

作者： Meng ma liu fu Xu Guo Zhi Zhai National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an710049China Department of Electrical and Computer Engineering University of Massachusetts LowellLowellMA 01854USA

Partial Differential Equation(PDE)is among the most fundamental tools employed to model dynamic *** PDE modeling methods are typically derived from established knowledge and known phenomena,which are time-consuming and ***,discovering governing PDEs from collected actual data via Physics Informed Neural Networks(PINNs)provides a more efficient way to analyze fresh dynamic systems and establish *** study proposes Sequentially Threshold Least Squares-Lasso(STLasso),a module constructed by incorporating Lasso regression into the Sequentially Threshold Least Squares(STLS)algorithm,which can complete sparse regression of PDE coefficients with the constraints of l0 *** further introduces PINN-STLasso,a physics informed neural network combined with Lasso sparse regression,able to find underlying PDEs from data with reduced data requirements and better *** addition,this research conducts experiments on canonical inverse PDE problems and compares the results to several recent *** results demonstrated that the proposed PINN-STLasso outperforms other methods,achieving lower error rates even with less data.

关键词： Physics-informed neural network inverse partial differential equation Lasso regression scientific machine learning

Antagonism effect of residual S triggers the dual-path mechanism for water oxidation

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Journal of Energy Chemistry 2024年第6期93卷 568-579,I0014页

作者： Li liu Jinming Cao Siqi Hu Tinghui liu Can Xu Wensheng fu Xinguo ma Xiaohui Yang Chongqing Key Laboratory of Green Catalytic materials and Technology College of ChemistryChongqing Normal UniversityChongqing 401331China School of Science Hubei University of TechnologyWuhan 430068HubeiChina Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China

Transition metal chalcogenides(TMCs)are recognized as pre-catalysts,and their(oxy)hydroxides derived from electrochemical reconstruction are the active species in the water ***,understanding the role of the residual chalcogen in the reconstructed layer is lacking in detail,and the corresponding catalytic mechanism remains ***,taking Cu_(1-x)Co_(x)S as a platform,we explore the regulating effect and existence form of the residual S doped into the reconstructive layer for oxygen evolution reaction(OER),where a dual-path OER mechanism is ***-principles calculations and operando~(18)O isotopic labeling experiments jointly reveal that the residual S in the reconstructive layer of Cu_(1-x)Co_(x)S can wisely balance the adsorbate evolution mechanism(AEM)and lattice oxygen oxidation mechanism(LOM)by activating lattice oxygen and optimizing the adsorption/desorption behaviors at metal active sites,rather than change the reaction mechanism from AEM to *** such a dual-path OER mechanism,Cu_(0.4)Co_(0.6)S-derived Cu_(0.4)Co_(0.6)OSH not only overcomes the restriction of linear scaling relationship in AEM,but also avoids the structural collapse caused by lattice oxygen migration in LOM,so as to greatly reduce the OER potential and improved stability.

关键词： Electrochemical reconstruction Adsorbate evolution mechanism Lattice oxygen oxidation mechanism Oxygen evolution reaction Residual sulfur