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Probing the Structural Stability, mechanical, Electronic, and Thermodynamic Properties of mg-Y-Zn Ternary Compounds via First-Principles Calculations

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Acta metallurgica Sinica(English Letters) 2024年第10期37卷 1703-1720页

作者： Wenjun Tian Yunxuan Zhou tao Deng tao Chen Jun Tan xianhua Chen Fusheng Pan National Engineering Research Center for magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing400044China Lanxi magnesium materials Research Institute Lanxi321100China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing400044China

magnesium alloys have large reserves and good strength,attracting a lot of ***,the thermodynamic,elastic constants,and electronic properties of the mg-Y-Zn ternary compounds were calculated;among them,mgYZn_(2) belongs to the cubic structure,mgYZn,mg_(3)Y_(2)Zn_(4),and mg_(14)YZn-1 belong to the hexagonal structure,mg_(6)YZn-1,mg_(6)YZn-2,mgY_(2)Zn,and mg_(14)YZn-2 possess the orthorhombic structure,and mg_(3)Y_(2)Zn_(3) is trigonal *** calculated cohesive energies of the results show that all compounds are thermodynamically ***,the mgYZn_(2) compound exhibits the highest modulus of 76.84 mPa,and the mg_(3)Y_(2)Zn_(3) has the biggest hardness of 6.6 *** addition,the mg_(6)YZn-2 has the strongest elastic anisotropic with A^(U) of 6.14 and A_(G) of 0.38,*** to the population analysis,the mg-Y covalent bond is due to the biggest bond *** shortest weighted average bond length indicates that mgYZn_(2) has better elastic ***,the calculated limiting thermal conductivity results show that mg_(14)YZn-2 has better thermal conductivity with max.m.m values of 0.94 W·m^(−1)·K^(−1) and 0.74 W·m^(−1)·K^(−1) for Clarke’s and Cahill’s models.

关键词： magnesium alloys First-principles calculations Elastic properties Electronic properties Thermodynamic properties

Nitsche-xFEm for a time fractional diffusion interface problem

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Science China mathematics 2024年第3期67卷 665-682页

作者： tao Wang Yanping Chen China Nuclear Power Technology Research Institute Co.Ltd. Shenzhen 518028China School of mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper, we propose a space-time finite element method for a time fractional diffusion interface problem. This method uses the low-order discontinuous Galerkin(DG) method and the Nitsche extended finite element method(Nitsche-xFEm) for temporal and spatial discretization, respectively. Sharp pointwise-in-time error estimates in graded temporal grids are derived, without any smoothness assumptions on the ***, three numerical ex.m.les are provided to verify the theoretical results.

关键词： fractional diffusion interface discontinuous Galerkin Nitsche-xFEm error estimates

Seasonal variations of mass absorption efficiency of elemental carbon in Pm_(2.5) in urban Guangzhou of South China

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Journal of Environmental Sciences 2023年第11期133卷 83-92页

作者： Chenglei Pei Yunfei Wu Jun tao Leiming Zhang tao Zhang Runqi Zhang Sheng Li State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China CAS Center for Excellence in Deep Earth Science Guangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Guangzhou Sub-branch of Guangdong Ecological and Environmental monitoring Center Guangzhou 518049China Key Laboratory of middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Institute for Environmental and Climate Research Jinan UniversityGuangzhou 510632China Air Quality Research Division Science and Technology BranchEnvironment and Climate Change CanadaTorontoCanada Guangdong Ecological and Environmental monitoring Center Guangzhou 510308China

This study investigates seasonal variations of mass absorption efficiency of elemental carbon(mAE_(EC))and possible influencing factors in urban Guangzhou of South *** concentrations of elemental carbon(EC)and organic carbon(OC)in Pm_(2.5) and aerosol absorption coefficient(b_(ap))at multi-wavelengths were simultaneously measured in four seasons of 2018-2019 at hourly resolution by a semi-continuous carbon analyzer and an *** average mass concentrations of EC were in the range of 1.36-1.70μgC/m^(3) with a lower value in summer than in the other seasons,while those of OC were in the range of 4.70–6.49μgC/m^(3) with the lowest value in summer and the highest in *** exhaust from local traffic was identified to be the predominant source of carbonaceous *** average aerosol absorption Angstrom exponents(AAE)were lower than 1.2 in four seasons,indicating EC and b_(ap) were closely related with vehicle *** mAE EC at 550 nm was 11.0,8.5,10.4 and 11.3 m^(2)/g in spring,summer,autumn,and winter,*** mAE EC was related with the high mass ratio of non-carbonaceous aerosols to EC and high ambient relative humidity.

关键词： Vehicle exhaust Non-carbonaceous aerosols Absorption enhancement Relative humidity

Bacterial diversity in sediments of core mD05-2902 from the xisha Trough,the South China Sea

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Acta Oceanologica Sinica 2014年第10期33卷 85-93页

作者： LI tao WANG Peng State Key Laboratory of marine Geology Tongji University Guangzhou marine Geological Survey

A sediment core mD05-2902 was collected from the deep-sea basin of the xisha Trough. The vertical distribution and diversity of bacteria in the core was investigated through ten sub-sampling with an interval of 1 m using bacterial 16 S rRNA gene as a phylogenetic bio-marker. Eighteen phylogenetic groups were identified from 16 S rRNA gene clone libraries. The dominant bacterial groups were JS1, Planctomycetes and Chloroflexi, which accounted for 30.6%, 16.6%, and 15.6% of bacterial clones in the libraries, respectively. In order to reveal the relationship between biotic and abiotic data, a nonmetric multidimensional scaling analysis was performed. The result revealed that the δ15N, δ13C, total organic carbon and total organic nitrogen possibly influenced the bacterial community structure. This study expanded our knowledge of the biogeochemical cycling in the xisha Trough sediment.

关键词： xisha Trough bacterial diversity 16S rRNA gene

Design and Fabrication of a Novel Core-Suspended Optic Fiber for Distributed Gas Sensor

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Photonic Sensors 2014年第2期4卷 97-101页

作者： tao ZHANG Key Laboratory of in-Fiber Integrated Optics Ministry Education of China Harbin Engineering University Harbin 150001 China College of Science Harbin Engineering University Harbin 150001 China postdoctoral Research Station of mechanical Engineering College of Mechanical and Electrical Engineering Harbin Engineering University Harbin 150001 China

We designed a novel core-suspended capillary fiber that the core was suspended in the air hole and close to the inner surface of the capillary, and experimentally demonstrated its fabrication technology. In addition, a method for linking a single mode fiber and a core-suspended fiber was proposed based on splicing and tapering at the fusion point between the two fibers. By combining with the optical time domain reflectometer technology, we constructed a distributed gas sensor system to monitor greenhouse gas based on this novel fiber.

关键词： Hollow fiber core-suspended linking distributed gas sensor

Seasonal size composition and abundance distribution of Euphausia pacifica in relation to environmental factors in the southern Yellow Sea

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Acta Oceanologica Sinica 2019年第2期38卷 70-77页

作者： tao Zuo Hui Liu Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Laboratory for marine Ecology and Environmental Science Pilot National Laboratory for Marine Science and Technology (Qingdao) Department of marine Biology Texas A&M University at Galveston

The seasonal size structure and spatial abundance distributions of Euphausia pacifica populations were investigated in the central part of southern Yellow Sea from August 2009 to may *** abundance and biomass of *** were higher in spring and summer,and lower in autumn and *** mean abundance and biomass(calculated by carbon)were 74.94 ind./m^3 and 8.23 mg/m^3,*** with total length(TL)ranging between 10 and 19 mm in summer had a substantial contribution to the population biomass,whereas larvae of TL of 3–7 mm in spring were the main contributor to the population *** sex ratio(female:male)showed a female bias in four *** value peaked in summer,and then decreased in autumn,spring,and winter *** analysis revealed that the length-frequency distribution of *** could be characterized as one group with large animals(mean TL>12 mm)accompanied by one or two subgroups of small individuals(mean TLmm).Regarding the spatial distribution,juveniles and adults of *** tend to concentrate in relatively deep water with low temperature(～11℃)and high salinity(>32),whereas its larvae showed more abundance in inshore water with rich chlorophyll a,low salinity(m temperature(>11℃),especially in summer and *** changed seasonally between stage-specific abundance and environmental factors.

关键词： spatial distribution size composition biomass Euphausia pacifica Yellow Sea

Nψ,φ-type Quotient modules over the Bidisk

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Acta mathematica Sinica,English Series 2020年第8期36卷 943-960页

作者： Chang Hui WU tao YU School of mathematical Sciences Qufu Normal UniversityQufu 273165P.R.China School of mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China

Let H^2(D^2)be the Hardy space over the bidisk D^2,and let mψ,φ=[(ψ(z)-φ(w))^2]be the submodule generated by(ψ(z)-φ(w))2,whereψ(z)andφ(w)are nonconstant inner *** related quotient module is denoted by Nψ,φ=H^2(D^2)Θmψ,φ.In this paper,we give a complete characterization for the essential normality of Nψ,φ.In particular,ifψ(z)=z,we simply write mψ,φand Nψ,φas mφand Nφ*** paper also studies compactness of evaluation operators L(0)|Nφand R(0)|Nφ,essential spectrum of compression operator Sz on Nφ,essential normality of compression operators Sz and Sw on Nφ.

关键词： Quotient module compression operators essential normality

Almost Periodic Type Group Actions on Compact Quantum metric Spaces

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Acta mathematica Sinica,English Series 2024年第2期40卷 568-594页

作者： Bo tao LONG Wei WU College of mathematics MIIT Key Laboratory of Mathematical Modelling and High Performance Computing of Air VehiclesNanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China School of mathematical Sciences Shanghai Key Laboratory of Pure Mathematics and Mathematical PracticeEast China Normal UniversityShanghai 200241P.R.China

A compact quantum metric space is a complete order unit space A endowed with a Lipnorm *** give some characterizations of almost periodic type group actions on a compact quantum metric space(A,L)by means of several kinds of subsets of A,its induced equicontinuous actions on several important subsets of the dual Banach space A*,and the Lip-norm L with its induced metric space structures on the state space S(A)of A.

关键词： Lip-norm compact quantum metric space Lipschitz isomorphism almost periodicity Arzela-Ascoli theorem metric set

Hyponymy Graph model for Word Semantic Similarity measurement

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Chinese Journal of Electronics 2015年第1期24卷 96-101页

作者： WANG Junhua ZUO Wanli PENG tao College of Computer Science and Technology Jilin University Key Laboratory of Symbol Computation and Knowledge Engineering attached to the ministry of Education

measuring word semantic similarity is a generic problem with a broad range of applications such as ontology mapping, computational linguistics and artificial intelligence. Previous approaches to computing word semantic similarity did not consider concept occurrence frequency and word’s sense number. This paper introduced Hyponymy graph, and based on which proposed a novel word semantic similarity model. For two words to be compared, we first retrieve their related concepts; then produce lowest common ancestor matrix and distance matrix between concepts; finally calculate distance-based similarity and information-based similarity, which are integrated to get final semantic similarity. The main contribution of our method is that both concept occurrence frequency and word’s sense number are taken into account. This similarity measurement more closely fits with human rating and effectively simulates human thinking process. Our experimental results on benchmark dataset m&C and R&G with Word Net2.1 as platform demonstrate roughly 0.9%–1.2%improvements over existing best approaches.

关键词： Word semantic similarity Concept semantic similarity Semantic similarity Hyponymy graph model Word Net.