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Phase-Field Simulation of Sintering Process:A Review

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1165-1204页

作者： Ming xue Min yi State Key Laboratory ofMechanics and Control forAerospace Structures&Institute for Frontier Science&Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education&College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics(NUAA)Nanjing210016China

Sintering,a well-established technique in powder metallurgy,plays a critical role in the processing of high melting point materials.A comprehensive understanding of structural changes during the sintering process is essential for effective product *** phase-field method stands out for its unique ability to simulate these structural *** its widespread application,there is a notable absence of literature reviews focused on its usage in sintering ***,this paper addresses this gap by reviewing the latest advancements in phase-field sintering models,covering approaches based on energy,grand potential,and entropy *** characteristics of various models are extensively discussed,with a specific emphasis on energy-based models incorporating considerations such as interface energy anisotropy,tensor-form diffusion mechanisms,and various forms of rigid particle motion during ***,the paper offers a concise summary of phase-field sintering models that integrate with other physical fields,including stress/strain fields,viscous flow,temperature field,and external electric *** conclusion,the paper provides a succinct overview of the entire content and delineates potential avenues for future research.

关键词： Phase-field model review sintering additive manufacturing

Some Convergence Properties for Weighted Sums of Martingale Difference Random Vectors

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1127-1142页

作者： yi WU xue Jun WANG School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000P.R.China School of Big Data and Statistics Anhui UniversityHefei 230601P.R.China

let{X_(ni),F_(ni);1≤i≤n,n≥1}be an array of R^(d)martingale difference random vectors and{A_(ni),1≤i≤n,n≥1}be an array of m×d matrices of real *** this paper,the Marcinkiewicz-Zygmund type weak law of large numbers for maximal weighted sums of martingale difference random vectors is obtained with not necessarily finite p-th(1lete convergence and strong law of large numbers are established under some mild *** application to multivariate simple linear regression model is also provided.

关键词： Martingale difference random vectors weighted sums Marcinkiewicz–Zygmund type weak law of large numbers complete convergence strong law of large numbers multivariate simple linear regression model

TERNARY　METALLIC　NUCleOTIDE　COMPleXES　WITH　POLYPYRIDYL　IN　SOLUTION：INFLUENCE　OF　SOLVENT　POLARITY　ON　THE　INTRAMOleCULAR　STACKING　INTERACTION　IN　THE　TERNARY　COMPleX　Cu（pdphen）（ATP）￣（2－）

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Chinese Chemical letters 1995年第12期6卷 1065-1068页

作者： xue yi le lei WANG Liang Nian JI (Department of Chemistry, Zhongshan Uviversity. Guangzhou, 510276)(State Key Laboratory of Coordination Chemistry, Nanjing University) Zhongshan Univ Dept Chem Guangzhou 510275 Peoples R China Nanjing Univ State Key Lab Coordinat Chem Nanjing Peoples R China

The stability constants of the ternary mixed ligand complex Cu(pdphen)(ATP)(2-), where pdphen is the planar ligand pyrido[3,2-f][1,7] phenanthroline, were determined by potentiometric pH titration in water,and in 30 and 50%(v/v) aqueous dioxane solutions. It has been observed from this information that a stronger stacking interaction between pdphen and the base pf ATP exists and decreases with decreasing selvent polarity i.e.,inereasing amounts of dioxane in the solvent mixture.

关键词： ATP pdphen Cu COMPleX

HLA-DR expression on regulatory T cells is closely associated with the global immune activation in HIV-1 infected subjects naive to antiretroviral therapy

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Chinese Medical Journal 2011年第15期124卷 2340-2346页

作者： XIAO Jian QIAN Ke-lei CAO Qing-hua QIU Chen-li QIU Cao xue yi-le ZHANG Xiao-yan ZHONG Ping XU Jian-qing LI Ming-yuan WANG ying Department of Microbiology West China School of preclimcal and Forensic Medicine Sichuan University Chengdu Sichuan 610041 China Department of AIDS/STD Shanghai Municipal Center for Disease Control and Prevention Shanghai 200336 China Shanghai Public Health Clinical Center Institutes of Biomedical Sciences Key Laboratory of Medical Molecular Virology of Ministry of Education/Health Shanghai Medical College Fudan University Shanghai 201508 China

Background The frequencies of regulatory T cells （Tregs） increased over the HIV infection but its counts actually decreased. We proposed that the decrease of Treg counts may cause the reduction of inhibitory effect and thereby account for the over-activation of Tregs during HIV infection. However, it remains unknown whether Tregs are also over-activated and thereafter the activation induced death may lead to the decrease of Tregs. Methods Tregs were defined as CD4＋CD25＋CD127lo/-T cells. Eighty-one HIV-1 infected patients were enrolled in our study, and twenty-two HIV-1 seronegative donors were recruited as the control. The levels of HLA-DR on Tregs were determined by FACSAria flow cytometer. Results Compared to HIV-1 seronegative donors, the levels of HLA-DR on CD4＋CD25＋CD127lo/- Tregs were significantly increased in HIV-1 infected patients, and its increase was positively associated with viral loads （r=0.3163, P=-0.004） and negatively with CD4 T-cell counts （r=-0.4153, P 〈0.0001）. In addition, significant associations between HLA-DR expression on CD4＋CD25＋CD127lo/- Tregs and the percentages of HLA-DR, CD38, Ki67 expressing CD4＋ and CD8＋ T cells were also identified. Conclusion HLA-DR on Tregs is a good marker for viral replication and disease progression. The over-activation of Tregs might result in the decrease of Tregs.

关键词： human immunodeficiency virus type 1 T-lymphocytes, regulatory HLA-DR antigens immune activation

Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

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Chinese Journal of Polymer Science 2024年第9期42卷 1360-1367,I0008页

作者： You-Cai xue yi-Ming Yang Di Jia Beijing National Laboratory for Molecular Sciences Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Polyampholyte gels,which have hierarchical structures,exhibit excellent self-healing properties and have great promise for biomaterials and *** investigated the relationship between microscopic structures and macroscopic viscoelastic properties of polyampholyte gels and found three factors influencing their viscoelastic properties,including the chemical crosslinking bonds,topological entanglements controlled by monomer concentration,and the ionic *** strength plays a major role on the strength of ionic bonds.A crossover point of elastic modulus and loss modulus was observed in the dynamic frequency sweeps at low monomer concentration or low chemical crosslinking density for gels with intermediate strength of ionic *** solid-liquid transition signaled by the crossover point is a typical feature of dynamic associated gels,representing the dynamical association-dissociation of the ionic bonds and full relaxation of the topological entanglements in the gel *** the crossover point disappears when the ionic bonds are too weak or too strong to form“permanent”***,in the non-linear yielding measurement,gels with intermediate strength of the ionic bonds are ductile and yield at very large shear strain due to the self-healing properties and the dynamic association-dissociation of the ionic *** the self-healing properties disappear when the ionic bond strength is too weak or too *** work reveals the mechanism of how the dynamic association-dissociation of ionic bonds influences both the linear and non-linear viscoelastic properties of the polyampholyte gels.

关键词： Polyampholyte gel Ionic bond Topological entanglement Self-healing Hierarchical structure

Rainbow Pancyclicity in a Collection of Graphs Under the Dirac-type Condition

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 269-274页

作者： Lu-yi LI Ping LI xue-liang LI Center for Combinatorics and LPMC Nankai UniversityTianjin 300071China School of Mathematics and Statistics Shaanxi Normal UniversityXi’an 710062China

let G={Gi:i∈[n]} be a collection of not necessarily distinct n-vertex graphs with the same vertex set V,where G can be seen as an edge-colored(multi)graph and each Gi is the set of edges with color i.A graph F on V is called rainbow if any two edges of F come from different Gis’.We say that G is rainbow pancyclic if there is a rainbow cycle Cℓof lengthℓin G for each integerℓ2[3,n].In 2020,Joos and Kim proved a rainbow version of Dirac’s theorem:Ifδ(Gi)≥2/n for each i∈[n],then there is a rainbow Hamiltonian cycle in *** this paper,under the same condition,we show that G is rainbow pancyclic except that n is even and G consists of n copies of Kn/2,n/*** result supports the famous meta-conjecture posed by Bondy.

关键词： rainbow Hamiltonian cycle rainbow pancyclic meta-conjecture

Ant-nest-inspired porous structure for MXene composites with high-performance energy-storage and actuating multifunctions

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Nano Research 2024年第7期17卷 6673-6685页

作者： yi Wang Guanfeng xue Zhiling Luo Wei Zhang Luzhuo Chen Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and EnergyFujian Normal UniversityFuzhou 350117China Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering Fuzhou 350117China

Integrating energy-storage devices(supercapacitors)and shape-deformation devices(actuators)advances the miniaturization and multifunctional development of soft ***,soft robots necessitate supercapacitors with high energy-storage performance and actuators with excellent actuation ***,inspired by ant nests,we present a porous structure fabricated by MXene-graphene-methylcellulose(M-GMC)composite,which overcomes the self-stacking of MXene nanosheets and offers a larger specific surface *** porous structure provides more channels and active sites for electrolyte ions,resulting in high energy storage *** areal capacitance of the M-GMC electrode reaches up to 787.9 mF·cm^(−2),significantly superior to that of the pristine MXene electrode(449.1 mF·cm^(−2)).Moreover,the M-GMC/polyethylene bilayer composites with energy storage and multi-responsive actuation functions are *** M-GMC is used as the electrode and the polyethylene is used as the encapsulation layer of the quasi-solid-state ***,the actuators fabricated by the bilayer composites can be driven by light or low voltage(≤9 V).The maximum bending curvature is up to 5.11 cm^(−1).Finally,a smart gripper and a fully encapsulated smart integrated circuit based on the M-GMC/polyethylene are *** smart gripper enables programmable control with multi-stage *** applications realize the intelligence and miniaturization of soft *** ant-nest-inspired M-GMC composites would provide a promising development strategy for soft robots and smart integrated devices.

关键词： MXene graphene ant nest supercapacitor actuator multi-functional

Striking Stabilization Effect of Spinel Cobalt Oxide Oxygen Evolution Electrocatalysts in Neutral pH by Dual-Sites Iron Incorporation

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Energy & Environmental Materials 2024年第2期7卷 156-164页

作者： Shuairu Zhu xue Wang Jiabo le Na An Jianming Li Deyu Liu Yongbo Kuang Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Zhejiang Institute of Tianjin University Research Center of New Energy Research Institute of Petroleum Exploration & Development Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Developing stable and efficient nonprecious-metal-based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical ***,cobalt-based spinels have drawn a considerable amount of attention but most of them operate in alkali ***,the frequently studied Co-Fe spinel system never exhibits appreciable stability in nonbasic conditions,not to mention attract further investigation on its key structural motif and transition states for activity ***,we report exceptional stable Co-Fe spinel oxygen evolution catalysts（～30% Fe is optimal） in a neutral electrolyte,owing to its unique metal ion arrangements in the crystal *** introduced iron content enters both the octahedral and tetrahedral sites of the spinel as Fe2+and Fe3+（with Co ions having mixed distribution as well）.Combining density functional theory calculations,we find that the introduction of Fe to Co3O4lowers the covalency of metal-oxygen bonds and can help suppress the oxidation of Co2+/3+and O2-.It implies that the Co-Fe spinel will have minor surface reconstruction and less lattice oxygen loss during the oxygen evolution reaction process in comparison with Co3O4and hence show much better *** findings suggest that there is still much chance for the spinel structures,especially using reasonable sublattices engineering via multi metal doping to develop advanced oxygen evolution catalysts.

关键词： dual-sites iron electrocatalyst stability neutral electrolyte oxygen evolution reaction spinel oxides

Epidemiological characteristics of tuberculosis incidence and its macro-influence factors in Chinese mainland during 2014–2021

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贫困所致传染病(英文) 2024年第3期13卷 43-57页

作者： Deng le-le Zhao Fei Li Zhuo-wei Zhang Wei-wei He Guang-xue Ren Xiang National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention Beijing China Department of Pharmacy Beijing Hospital National Center of Gerontology Institute of Geriatric Medicine Chinese Academy of Medical Science Beijing Key Laboratory of Drug Clinical Risk and Personalized Medication Evaluation Beijing China Miyun District Center for Disease Control and Prevention Beijing China School Of Public Health Binzhon Medical University Yantai China Division of Infectious Disease Key Laboratory of Surveillance and Early-Warning On Infectious Disease Chinese Center for Disease Control and Prevention Beijing China

Background Tuberculosis (TB) remains a pressing public health issue, posing a significant threat to individuals'' well-being and lives. This study delves into the TB incidence in Chinese mainland during 2014–2021, aiming to gain deeper insights into their epidemiological characteristics and explore macro-level factors to enhance control and *** TB incidence data in Chinese mainland from 2014 to 2021 were sourced from the National Notifiable Disease Reporting System (NNDRS). A two-stage distributed lag nonlinear model (DLNM) was constructed to evaluate the lag and non-linearity of daily average temperature (℃, Atemp), average relative humidity (%, ARH), average wind speed (m/s, AWS), sunshine duration (h, SD) and precipitation (mm, PRE) on the TB incidence. A spatial panel data model was used to assess the impact of demographic, medical and health resource, and economic factors on TB *** A total of 6,587,439 TB cases were reported in Chinese mainland during 2014–2021, with an average annual incidence rate of 59.17/100,000. The TB incidence decreased from 67.05/100,000 in 2014 to 46.40/100,000 in 2021, notably declining from 2018 to 2021 (APC =-8.87%, 95%CI: -11.97, -6.85%). TB incidence rates were higher among males, farmers, and individuals aged 65 years and older. Spatiotemporal analysis revealed a significant cluster in Xinjiang, Qinghai, and Xizang from March 2017 to June 2019 (RR= 3.94,P 71.73%), low sunshine duration (le extreme low wind speed (< 2.79 m/s) decreased the risk. The spatial Durbin model showed positive associations between TB incidence rates and se

关键词： Tuberculosis Surveillance Epidemiological characteristics Incidence Influence factor Distributed lag nonlinear model (DLNM) Spatial panel model China