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mechanical Properties and Electronic Structures of m(m=Ti,V,Cr,mn and Fe)Dopedβ-Si_(3)N_(4) from First-Principle

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Journal of Wuhan University of Technology(materials Science) 2024年第3期39卷 639-644页

作者：龙敏黄福祥 XU liangyu lI Xuemei YANG Zhou lENG Yue mei Shini School of materials Science and Engineering Chongqing University of TechnologyChongqing 400054China

The structures,mechanical properties and electronic structures of m metals(m=Ti,V,Cr,mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within *** calculated lattice parameters ofβ-Si_(3)N_(4) were consistent with previous *** cohesive energy and formation enthalpy show that initialβ-Si_(3)N_(4) has the highest structural *** calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli ofβ-Si_(3)N_(4) are slightly reduced by m *** on Poisson’s and Pugh’s ratio,β-Si_(3)N_(4) is a ductile material and the toughness ofβ-Si_(3)N_(4) increases with m doping,and Fe doping exhibited the best *** results of density of states,charge distributions and overlapping populations indicate thatβ-Si_(3)N_(4) has the strong covalent and ionic bond strength between N and Si.

关键词： first-principles β-Si_(3)N_(4) mechanical properties electronic structure

Effects of the properties of mg(OH)_(2)precursor on the hydrothermal synthesis of magnesium oxysulfate whiskers

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Particuology 2024年第9期92卷 13-23页

作者： Thanayos Boonrit mei Yang Guangwen Chen Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian116023China University of Chinese Academy of Sciences Beijing100049China

magnesium oxysulfate(mOS)whiskers are commonly synthesized through a dissolution-precipitation mechanism,wherein mg(OH)_(2)dissolves to form mg(OH)64−,followed by reactions with SO_(4)^(2−)and H_(2)O to yield mOS ***,the impact of mg(OH)_(2)precursor properties on the formation process of mOS whiskers has been insufficiently explored,and sector-like and needle-like morphologies were both observed in previous *** this study,we systematically investigated how the properties of mg(OH)_(2)precursors influenced the crystalline structure and morphology of mOS *** various experimental conditions,mgSO_(4)·5mg(OH)_(2)·2H_(2)O(152mOS)whiskers were consistently obtained,regardless of mg(OH)_(2)morphology and *** size of mg(OH)_(2)emerged as a critical factor in shaping the morphology of 152mOS ***-sized mg(OH)_(2)(≤106±37 nm)favored the formation of sector-like whiskers,while larger-sized mg(OH)_(2)(≥206±98 nm)encouraged the development of needle-like *** distinction was attributed to the slower dissolution rate exhibited by larger-sized mg(OH)_(2),maintaining a smaller number of 152mOS nuclei and promoting the growth of needle-like whiskers instead of the aggregation of 152mOS nuclei into sector-like *** addition,the effects of the molar ratio of mg^(2+)to SO_(4)^(2−)and hydrothermal temperature were also *** average length and diameter of the needle-like whiskers prepared with mg(OH)_(2)of 331±145 nm under optimized conditions were 77±32 and 0.39±0.10μm,*** study presented an effective strategy for controlling the morphology of 152mOS whiskers.

关键词： magnesium oxysulfate whiskers morphology control Precursor microreactor

Compensation temperatures and hysteresis behaviors of a graphene-like trilayer

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Communications in Theoretical Physics 2024年第5期76卷 166-179页

作者： Ying An Ji liang Wei Wang mei-mei Du Feng-ge Zhang School of Science Shenyang University of TechnologyShenyang 110870China School of Electrical Engineering Shenyang University of TechnologyShenyang 110870China

This work focuses on the ground-state phase diagram,the compensation temperatures and the critical behaviors of a ferrimagnetic graphene-like trilayer induced by crystal fields and exchange *** simulation results show that a negative decrease in crystal field or an increase in exchange coupling can increase the critical *** importantly,an m curve with double compensation temperatures can be observed,which is not predicted by the Neel *** remarkable compensation phenomenon has potential application value in the field of magnetic recording.

关键词： graphene-like trilayer mixed-spin Ising model magnetization double compensation temperatures triple-loop hysteresis monte Carlo

On calculating glacial isostatic adjustment

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Geodesy and Geodynamics 2024年第5期15卷 441-452页

作者： l.m.Cathles Cornell University IthacaNY 14853USA

modeling the earth's fluid and elastic response to the melting of the glaciers of the last ice age is the most direct way to infer the earth's radial viscosity ***,we compare two methods for calculating the viscoelastic response to surface *** one,the elastic equation of motion is converted to a viscoelastic equation using the Correspondence *** the other,elastic deformation is added to the viscous flow as isostatic adjustment *** two modeling methods predict adjustment histories that are different enough to potentially impact the interpretation of the observed glacial isostatic adjustment(GIA).The differences arise from buoyancy and whether fluid displacements are subjected to hydrostatic *** methods agree if they use the same equations and boundary *** origin of the differences is determined by varying the boundary conditions and pre-stress application.

关键词： Glacial isostatic adjustment Viscoelastic normal.m.des Hydrostatic pre-stress Elastic buoyancy Correspondence principle

Facile preparation of coal-based ultramicroporous carbon microspheres for selective CO_(2)capture

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Carbon Resources Conversion 2024年第3期7卷 97-105页

作者： mei An Tuo Guo Qingjie Guo Jiangmen laboratory of Carbon Science and Technology the Hong Kong University of Science and Technology(Guangzhou)JiangmenGuangzhou 529000China State Key laboratory of High-efficiency Coal Utilization and Green Chemical Engineering School of Chemistry and Chemical EngineeringNingxia UniversityYinchuanNingxia 750021China Key laboratory of Clean Chemical Engineering in Universities of Shandong College of Chemical EngineeringQingdao University of Science&TechnologyQingdao 266042China

The basic structure of aromatic compounds that are abundant in coal is the carbonaceous precursor derived from carbon ***,it remains to be a huge challenge to prepare carbon microspheres using coal due to the complex construction and composition of ***,a simple and viable way to obtain coal-based microporous carbon microspheres was developed by means of ethanol pyrolysis and a sequential extraction *** as-prepared carbon microsphere featured aspherical.m.cron particles of a uniform size(0.6-1.6㎛),abundant O-functional groups,excellent thermal stability,high SBET(415.5-983.2 m^(2)/g),and plentiful ultra-micropores(63.15-72.72%).The coal-based carbon microsphere exhibited a noteworthy CO_(2)uptake(3.19-4.97 mmol/g at 273 K and 1.0 bar),acceptable CO_(2)/N_(2)selectivity(IAST:23-46)and moderate isosteric heats(20-32 kJ/mol).This synthetic strategy is important for the preparation of ultramicroporous carbon microspheres using coal,and the synthetic carbon microspheres have promising prospects for highly efficient CO_(2)capture.

关键词： Coal Ultramicroporous Carbon microspheres Ethanolysis Sequential extraction CO_(2)capture

l.m.t Theorems for Critical Galton-Watson Processes with Immigration Stopped at Zero

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Acta mathematica Sinica,English Series 2024年第2期40卷 435-450页

作者： Dou Dou lI mei ZHANG Xian Yu ZHANG College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China laboratory of mathematics and Complex Systems(ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero *** precise estimation on the probability generating function of the n-th population are obtained,and the tail prob... 详细信息

关键词： Branching immigration critical life period l.m.t theorems

Facile synthesis of composite polyferric magnesium-silicate-sulfate coagulant with enhanced performance in water and wastewater

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International Journal of minerals,metallurgy and materials 2024年第3期31卷 574-584页

作者： Xiangtao Huo Rongxia Chai lizheng Gou mei Zhang min Guo School of metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The coagulation process is a widely applied technology in water and wastewater *** composite polyferric mag-nesium-silicate-sulfate(PFmS)coagulants were synthesized using Na_(2)SiO_(3)·9H_(2)O,Fe_(2)(SO_(4))_(3),and mgSO_(4) as raw materials in this *** effects of aging time,Fe:Si:mg,and OH:m molar ratios(m represents the metal ions)on the coagulation performance of the as-pre-pared PFmS were systematically investigated to obtain optimum *** results showed that PFmS coagulant exhibited good co-agulation properties in the treatment of simulated humic acid-kaolin surface water and reactive dye *** the molar ratio was controlled at Fe:Si:mg=2:2:1 and OH:m=0.32,the obtained PFmS presented excellent stability and a high coagulation *** removal efficiency of ultraviolet UV254 was 99.81%,and the residual turbidity of the surface water reached 0.56 NTU at a dosage of 30 mg·l^(-1).After standing the coagulant for 120 d in the laboratory,the removal efficiency of UV254 and residual turbidity of the surface wa-ter were 88.12%and 0.68 NTU,respectively,which accord with the surface water treatment *** addition,the coagulation performance in the treatment of reactive dye wastewater was greatly improved by combining the advantages of magnesium and iron *** with polyferric silicate-sulfate(PFS)and pol.m.gnesium silicate-sulfate(PmS),the PFmS coagulant played a better decolor-ization role within the pH range of 7-13.

关键词： polyferric-magnesium-silicate-sulfate composite coagulants water and wastewater excellent stability high coagulation ef-ficiency decolorization

Cosmological interpretation for the stochastic signal in pulsar timing arrays

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Science China(Physics,mechanics & Astronomy) 2024年第4期67卷 43-50页

作者： Yu-mei Wu Zu-Cheng Chen Qing-Guo Huang School of Fundamental Physics and mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China CAS Key laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The pulsar timing array(PTA)collaborations have recently reported compelling evidence for a stochastic signal consistent with a gravitational-wave *** this paper,we combine the latest data sets from NANOGrav,PPTA,and EPTA to explore cosmological interpretations for the PTA signal from first-order phase transitions,domain walls,and cosmic strings,*** find that the domain wall.m.del is strongly disfavored with the Bayes factors compared with the first-order phase transitions and cosmic strings being 1/90 and 1/189,respectively,breaking the degeneracy among these models in individual data *** also find that:(1)a strong phase transition at temperatures below the electroweak scale is favored,and the bubble collisions make the dominant contribution to the energy density spectrum;(2)a small reconnection probability pllowed by strings in(super)string theory is favored at the 95%confidence level,and ground-based detectors can further constrain the parameter space.

关键词： puslar timing arrays gravitational-wave background first-order phase transitions domain walls cosmic strings

Feature matching via Topology-Aware Graph Interaction model

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 113-130页

作者： Yifan lu Jiayi ma Xiaoguang mei Jun Huang Xiao-Ping Zhang the Electronic Information School Wuhan UniversityWuhan 430072China IEEE Tsinghua Berkeley Shenzhen Institute Shenzhen 518071China the Department of Electrical Computer and Biomedical EngineeringToronto Metropolitan UniversityToronto ON M5B 2K3Canada

Feature matching plays a key role in computer vision. However, due to the l.m.tations of the descriptors, the putative matches are inevitably contaminated by massive *** paper attempts to tackle the outlier filtering probl.m.from two aspects. First, a robust and efficient graph interaction model,is proposed, with the assumption that matches are correlated with each other rather than independently distributed. To this end, we construct a graph based on the local relationships of matches and formulate the outlier filtering task as a binary labeling energy minimization probl.m. where the pairwise term encodes the interaction between matches. We further show that this formulation can be solved globally by graph cut algorithm. Our new formulation always improves the performance of previous localitybased method without noticeable deterioration in processing time,adding a few milliseconds. Second, to construct a better graph structure, a robust and geometrically meaningful topology-aware relationship is developed to capture the topology relationship between matches. The two components in sum lead to topology interaction matching(TIm), an effective and efficient method for outlier filtering. Extensive experiments on several large and diverse datasets for multiple vision tasks including general feature matching, as well as relative pose estimation, homography and fundamental.m.trix estimation, loop-closure detection, and multi-modal image matching, demonstrate that our TIm is more competitive than current state-of-the-art methods, in terms of generality, efficiency, and effectiveness. The source code is publicly available at http://***/Yifanlu2000/TIm.

关键词： Feature matching graph cut outlier filtering topology preserving