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Stability of the Phase Separation State for Compressible Navier-Stokes/Allen-Cahn System

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 45-74页

作者： Ya-zhou Chen Hakho hong Xiao-ding Shi Department of Mathematics College of Mathematics and PhysicsBeijing University of Chemical TechnologyBeijing100029China Institute of Mathematics State Academy of SciencesPyongyangKorea

This paper is concerned with the large time behavior of the Cauchy problem for Navier-Stokes/AllenCahn system describing the interface motion of immiscible two-phase flow in 3-D. The existence and uniqueness of global solutions and the stability of the phase separation state are proved under the small initial perturbations. Moreover, the optimal time decay rates are obtained for higher-order spatial derivatives of density,velocity and phase. Our results imply that if the immiscible two-phase flow is initially located near the phase separation state, then under small perturbation conditions, the solution exists globally and decays algebraically to the complete separation state of the two-phase flow, that is, there will be no interface fracture, vacuum, shock wave, mass concentration at any time, and the interface thickness tends to zero as the time t → +∞.

关键词： Navier-Stokes/Allen-Cahn system existence uniqueness large time behavior decay rate

Development of lithium-free P2-type high-sodium content cathode materials with enhanced cycle and air stability for sodium-ion batteries

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Rare Metals 2024年第1期43卷 113-123页

作者： Jin-Lv Tian Lin-Rong Wu Hai-Jun Zhao shou-Dong Xu Liang Chen ding Zhang Xiao-Chuan Duan College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China

The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this *** on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation ***,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at *** addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 *** study provides new insight into the development of durable cathode materials for sodium-ion batteries.

关键词： Sodium-ion batteries Cathode material High sodium content Air stability

Experimental Study on Towing Characteristics of Composite Bucket Wellhead Platform

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China Ocean Engineering 2024年第3期38卷 531-542页

作者： ZHANG Pu-yang LIU Ying-fei LE Cong-huan ding hong-yan BAI Yu State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China

With the rapid development of large-scale development of marginal oilfields in China,simple wellhead platforms that are simple in structure and easy to install have become an inevitable choice in the process of oilfield ***,traditional simple wellhead platforms are often discarded after a single *** pursuit of a more costeffective approach to developing marginal oilfields,this paper proposes a new offshore oil field development facility—an integrated bucket foundation for wellhead *** verify the safety of its towing behavior and obtain the dynamic response characteristics of the structure,this paper takes a bucket integrated bucket foundation for wellhead platform with a diameter of 40 m as the research *** combining physical model tests and numerical simulations,it analyzes the static stability and dynamic response characteristics of the structure during towing,complete with the effects of the draft,wave height,wave period,and towing point height,which produce the dynamic responses of the structure under different influence factors,such as roll angle,pitch angle,heave acceleration and towing force as well as the sensibility to transport *** results show that the integrated bucket foundation for wellhead platform is capable of self-floating towing,and its movement is affected by the local environment,which will provide a reference for actual projects.

关键词： composite bucket foundation wellhead platform air flotation towing model test

Numerical evaluations on the fluid production in the in-situ conversion of continental shale oil reservoirs

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Petroleum Science 2024年第04期21卷 2485-2501页

作者： Zhao-Bin Zhang Maryelin Josefina Brice?o Montilla shou-ding Li Xiao Li Jian-Peng Xing Yan-Zhi Hu Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Earth Sciences Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences Institute of Energy Peking University

In-situ conversion presents a promising technique for exploiting continental oil shale formations,characterized by highly fractured organic-rich rock. A 3D in-situ conversion model, which incorporates a discrete fracture network, is developed using a self-developed thermal-flow-chemical(TFC) *** of the model elucidates the in-situ conversion process in three stages and defines the transformation of fluids into three distinct outcomes according to their end stages. The findings indicate that kerogen decomposition increases fluid pressure, activating fractures and subsequently enhancing permeability. A comprehensive analysis of activated fracture permeability and heating power reveals four distinct production modes, highlighting that increasing heating power correlates with higher cumulative fluid production. Activated fractures, with heightened permeability, facilitate the mobility of heavy oil toward production wells but hinder its cracking, thereby limiting light hydrocarbon ***, energy efficiency research demonstrates the feasibility of the in-situ conversion in terms of energy utilization, especially when considering the surplus energy from high-fluctuation energy sources such as wind and solar power to provide heating.

关键词： In-situ conversion Continental shale oil Natural fracture network TFC model

Inter-agency government information sharing under data-driven blockchain framework

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控制理论与应用 2024年第8期41卷 1369-1376页

作者： XIAO Jiong-en hong Ming ding Li-ping International Business School Guangdong University of Finance and EconomicsGuangzhou Guangdong 510320China Department of Electronic Business South China University of TechnologyGuangzhou Guangdong 510641China Institute of Software Chinese Academy of SciencesBeijing 100190China Guangzhou Institute of Software Application Technology Electronic Forensics LaboratoryGuangzhou Guangdong 511400China

The inter-agency government information sharing(IAGIS)plays an important role in improving service and efficiency of government ***,there is still no effective and secure way for data-driven IAGIS to fulfill dynamic demands of information sharing between government *** by blockchain and data mining,a data-driven framework is proposed for IAGIS in this ***,the blockchain is used as the core to design the whole framework for monitoring and preventing leakage and abuse of government information,in order to guarantee information ***,a four-layer architecture is designed for implementing the proposed ***,the classical data mining algorithms PageRank and Apriori are applied to dynamically design smart contracts for information sharing,for the purposed of flexibly adjusting the information sharing strategies according to the practical demands of government agencies for public management and public ***,a case study is presented to illustrate the operation of the proposed framework.

关键词： government data processing blockchain PageRank apriori

Social network learning efficiency in the principal-agent relationship

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Journal of Management Science and Engineering 2024年第2期9卷 193-219页

作者： Chuan ding Yilin hong Yang Li Peng Liu School of Mathematics Southwestern University of Finance and EconomicsChengdu611130China S.C.Johnson College of Business Cornell UniversityIthacaNY14853USA

Under the bounded rationality assumption,a principal rarely provides an optimal contract to an *** from others is one way to improve such a *** paper studies the efficiency of social network learning(SNL)in the principal–agent *** first introduce the Cobb-Douglas production function into the classic Holmstrom and Milgrom(1987)model with a constant relative risk-averse agent and work out the theoretically optimal *** are then designed to model the SNL process based on profit gaps between contracts in a network of *** the uncertainty of the agent's labor output,we find that the principals can reach a consensus that tends to result in overcompensation compared to the optimal ***,this study examines how network attributes and model parameters impact learning efficiency and posits several summative *** simulation results validate these hypotheses,and we discuss the relevant economic implications of the observed changes in SNL efficiency.

关键词： Simulation Social network learning Principaleagent Reaching consensus Learning efficiency

Induced Absolute Configuration of Achiral Tetradentate Ligands in Metal–Organic Frameworks for Circularly Polarized Luminescence

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Chinese Journal of Chemistry 2024年第11期42卷 1260-1266页

作者： hong-Ru Fu Dan-Dan Ren Kun Zhang hong Chen Xiaoyan Lu Qing-Rong ding Lu-Fang Ma College of Chemistry and Chemical Engineering Luoyang Normal UniversityLuoyangHenan471934 China College of Materials&Chemical Engineering China Three Gorges UniversityYichangHubei443002 China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002 China

The crystallization of chiral molecules is of great significance to understand the origin and evolution of hierarchical chirality and reveal the relationships between structural chirality and circularly polarized luminescence(CPL)***,we report two pairs of chiral metal–organic frameworks(MOFs)(DCF-17/LCF-17,DCF-18/LCF-18)by utilizing tetradentate ligands tetra(3-imidazoylphenyl)ethylene(TIPE)and 4,4'-[4',5'-bis[4-(4-pyridinyl)phenyl][1,1':2',1”-terphenyl]-4,4”-diyl]bis[pyridine](TPPP)as *** can be observed that the spontaneous resolution of the achiral ligands is converted into the induced resolution,and the ligands form the absolute configuration by using enantiopure camphoric acid(cam)as chiral induced reagent(CIR).As a result,the racemate MOFs can be driven to generate absolute homochiral *** two achiral MOFs[Cd(D-cam)(TPPP)_(0.5)](AF-1,AF=achiral framework)and[Cd(L-cam)(TPPP)_(0.5)](AF-2)were *** position disorder of D/L-cam skeleton causes the generation of nonchiralization,further leading to disappearance of symmetry breaking of *** the perspective of structure,this is the first report which reveals the chiral transfer and nonchiralization between chiral induced agents and tetradentate ***,DCF-17 and LCF-17 show CPL with luminescence dissymmetry factor(glum)of–1.0×10^(-2)and+9.2×10^(–3),*** work provides the useful evidences to reveal the induced chiral crystallization and the construction of CPL-active crystalline materials.

关键词： Metal-organic frameworks Circularly polarized luminescence Chirality induction Spontaneous resolution Chirality transfer

Simultaneous acceleration of sulfur reduction and oxidation on bifunctional electrocatalytic electrodes for quasi-solid-state Zn–S batteries

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Science China Chemistry 2024年第5期67卷 1531-1538页

作者： Mingli Wang hong Zhang Tianhang ding Fangjun Wu Lin Fu Bin Song Pengfei Cao Ke Lu Institutes of Physical Science and Information Technology School of Materials Science and EngineeringKey Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui UniversityHefei 230601China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China State Key Lab of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The incomplete sulfur reduction and high ZnS re-oxidation energy barrier along with severe side reactions during the battery cycling compromise the practical application of Zn–S electrochemistry. Herein, a bifunctional electrocatalytic sulfur matrix that simultaneously accelerates the sulfur reduction and ZnS oxidation is proposed to realize a highly-efficient Zn–S cell. It is revealed that the N-heteroatom hotspots are more favorable for facilitating the conversion of S to ZnS while the CoO nanocrystal substantially lowers the ZnS activation energy barrier thereby suppressing the formation of disproportionation species(e.g.,SO_(4)^(2-)) and accumulation of inactive ZnS. Accordingly, the Co O anchored on the N-doped carbon-supported sulfur cathode delivers a high Zn^(2+)storage capacity of 1,172 m Ahg^(-1)and outstanding cycling stability with a capacity retention of 71.6% after500 cycles with a high average Coulombic efficiency of 97.8%. Simultaneously, the stable cycling of solid-state Zn–S pouch cells with an energy density of 585 Whkg^(-1)sulfuris also demonstrated. Moreover, the postmortem analysis reveals that the degradation of Zn–S cells is mainly attributed to the limited reversibility of Zn anodes rather than the ZnS decomposition and/or accumulation. The approach to the bidirectional catalysis manipulated the sulfur redox provides a new perspective to realize the theoretical potentials of Zn–S cells.

关键词： Zn–S battery bifunctional catalysts solid-state battery sulfur redox degradation mechanism

Changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

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Advances in Climate Change Research 2024年第2期15卷 265-274页

作者： Yong YANG Ren-Sheng CHEN Yong-Jian ding hong-Yuan LI Zhang-Wen LIU Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different ***,the changes in land surface freeze-thaw processes under climate change on a global scale are still *** on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to *** results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,*** FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to *** annual FG areas in the NH,SH,and globe all show significant decreasing trends(p<0.05)from 1950 to 2020 at-0.32×10^(6),-0.22×10^(6),and-0.54×10^(6)km^(2)per decade,*** FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD *** prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming