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Multi-scale collaborative design method for macroscopic thermal optimization and mesoscopic woven structure of hypersonic vehicle's TOCMC leading edge

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Chinese Journal of Aeronautics 2024年第4期37卷 524-541页

作者： chenwei ZHAO Zecan TU Junkui MAO jian HUI Pingting chen College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 21016China Integrated Energy Institute Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A new thermal protection design method for hypersonic vehicle's leading edge is proposed, which can effectively reduce temperature of the leading edge without additional cooling measures. This method reduces the leading-edge's temperature by the multi-scale collaborative design of the macroscopic thermal optimization and the mesoscopic woven structures of Three-dimensional Orthogonal Woven Ceramic Matrix Composites(TOCMC). The macroscopic thermal optimization is achieved by designing different mesoscopic woven structures in different regions to create combined heat transfer channels to dredge the heat. The combined heat transfer channel is macroscopically represented by the anisotropic thermal conductivity of TOCMC. The thermal optimization multiple linear regression model is established to optimize the heat transport channel, which predicts Theoretical Optimal Thermal Conductivity Configuration(TOTCC) in different regions to achieve the lowest leading-edge temperature. The function-oriented mesostructure design method is invented to design the corresponding mesostructure of TOCMC according to the TOTCC, which consists of universal thermal conductivity prediction formulas for TOCMC. These universal formulas are firstly derived based on the thermal resistance network method, which is verified by experiments with an error of 6.25%. The results show that the collaborative design method can effectively reduce the leading edge temperature by about 12.8% without adding cooling measures.

关键词： Multi-scale collaborative design Thermal optimization Ceramic matrix composite Hypersonic vehicle Thermal protection Intelligent optimization

Capturing carbon dioxide from air by using amine-functionalized metal-organic frameworks

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Chinese Journal of Structural Chemistry 2024年第5期43卷 3-4页

作者： jian Yang Guang Yang Zhijie chen Stoddart Institute of Molecular Science Department of ChemistryState Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang UniversityHangzhou310058PR China Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials ZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou311215PR China

Along with the rapid rise of industry and technology,carbon dioxide(CO_(2))is released as a major by-product of fossil fuels *** continuous CO_(2)emission results in a steep increase of atmospheric CO_(2)concentrations and precipitated severe environmental and climatic ***,it is of great importance to reduce CO_(2)emission and atmospheric CO_(2)*** CO_(2)directly from air is one of the most straightforward strategies to mitigate atmospheric CO_(2)concentrations[1].

关键词： dioxide straight carbon

LaMnO_(3)/Co_(3)O_(4) nanocomposite for enhanced triethylamine sensing properties

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Journal of Rare Earths 2024年第4期42卷 733-742页

作者： jian Zhang Yanping chen Ling Li Xue chen Wenya An Xiujuan Qian Yuye Tao School of Science Shandong Jianzhu UniversityJinan250100China

LaMnO_(3) modified Co_(3)O_(4) nanocomposites were prepared by simple hydrothermal method co mbined with sol-gel *** gas sensitivity properties of pure Co_(3)O_(4) and LaMnO_(3)/Co_(3)O_(4) with different composite proportions are *** is found that 0.6-LMO/Co_(3)O_(4) sensor has higher sensitivity to triethylamine(TEA)than pure Co_(3)O_(4) sensor,which is improved by 9.27 *** the working temperature is reduced from 150 to 130℃.Besides,it has excellent gas selectivity and *** improvement of the gas sensitivity of LaMnO_(3)/Co_(3)O_(4) sensor may be due to the fact that LaMnO_(3) is an effective catalyst,and the catalytic performance perhaps is beneficial to improving the sensing *** addition,the formation of p-p heterojunctions may be the key factor to improve the gas sensing *** work provides a new Co_(3)O_(4)-based gas sensing material for the detection of TEA.

关键词： Gas sensing Co_(3)O_(4) LaMnO_(3) Triethylamine Rareearths

Trace elements in magmatic and hydrothermal quartz:Implications on the genesis of the Xingluokeng Tungsten Deposit,South China

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Acta Geochimica 2024年第3期43卷 441-458页

作者： Qing-Qing Zhang You-Wei chen jian-Feng Gao State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China

The Xingluokeng deposit is the largest gran-ite-related tungsten deposit within the Wuyi metallogenic belt in South *** Xingluokeng intrusion primarily consists of porphyritic biotite granite,biotite granite,andfine-grained *** deposit is represented by veinlet-disseminated mineralization with K-feldspathization and biotitization,alongside quartz-vein mineralization with gre-isenization and *** study investigates in-situ analyses of quartz compositions from both the intrusion and hydrothermal veinlets and *** element correlations indicate that trivalent Al^(3+)and Fe^(3+)replace Si^(4+)within the quartz lattice,with monovalent cations(such as Li^(+),Na^(+),and K^(+))primarily serving as charge *** Ge/Al ratios(<0.013)of quartz from granites suggest a mag-matic *** low Al/Ti and Ge/Ti ratios,accompanied by high Ti contents in quartz,suggest that the porphyritic biotite granite and biotite granite are characterized by rela-tively low levels of differentiation and high crystallization *** contrast,thefine-grained granite exhibits a higher degree of fractionation,lower crystallization tem-peratures,and a closer association with tungsten *** contents in quartz from quartz veins indicate Qz-Ⅰformed at temperatures above 400°C,while Qz-Ⅱto Qz-Ⅴformed at temperatures below 350°*** in different generations of quartz,as indicated by Al content and(Al+Fe)/(Li+Na+K)ratio,suggest that Qz-Ⅰprecipi-tated from a less acidicfluid with a stable pH,whereas Qz-Ⅱto Qz-Ⅴoriginated from a more acidicfluid with notable pH ***,alkaline alteration and acidic alteration supplied the essential Ca and Fe for the precipita-tion of scheelite and wolframite,respectively,highlighting a critical mechanism in tungsten mineralization at the Xin-gluokeng deposit.

关键词： Quartz Xingluokeng Tungsten deposit Trace elements South China

Cobalt-nanoparticle catalysts derived from zeolitic imidazolate framework@MXene composites for efficient oxidative self-coupling of benzylamines

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Frontiers of Chemical Science and Engineering 2024年第1期18卷 95-106页

作者： Jie chen Mingyuan jian Deqiong Xie Kecan Dou Deli chen Weidong Zhu Fumin Zhang Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China

In this study,we synthesize a catalyst comprising cobalt nanoparticles supported on MXene by pyrolyzing a composite in a N2 ***,the composite comprises a bimetallic Zn/Co zeolitic imidazole framework grown in situ on the outer surface of *** catalytic efficiency of the catalyst is tested for the self-coupling of 4-methoxybenzylamine to produce value-added imine,where atmospheric oxygen(1 atm)is used as the *** on the results,the catalyst displayed impressive catalytic activity,achieving 95.4%yield of the desired imine at 383 K for 8 ***,the catalyst showed recyclability and tolerance toward benzylamine substrates with various functional *** outstanding performance of the catalyst is primarily attributed to the synergetic catalytic effect between the cobalt nanoparticles and MXene support,while also benefiting from the three-dimensional porous ***,a preliminary investigation of potential reaction mechanisms is conducted.

关键词： MXene sacrificial template oxidative self-coupling Co nanoparticles imine

Experimental Study on Engineering Behavior of Solidified Soil for Scour Repair and Protection

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China Ocean Engineering 2024年第4期38卷 625-635页

作者： WU Xiao-ni LI Ru-yu SHU jian TANG Chao chen Jin-jian WANG Hui-li jianG Hai-li WANG Xiao State Key Laboratory of Ocean Engineering Department of Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Road and Bridge Group Co. Ltd.Shanghai 200433China Shanghai Engineering Research Center of Urban Infrastructure Renewal Shanghai 200032China jiangsu Kunze Technology Co. Ltd.Nanjing 210000China

A new scour countermeasure using solidified slurry for offshore foundation has been proposed *** solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies *** the pumping operation and solidification,the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-scour performance related retention rate in solidification and bearing capacity related strength property after *** this study,a series of laboratory tests are conducted to investigate the effects of mix proportion(initial water content and binder content)on the flow value,rheological properties,density,retention rate of solidified slurry and unconfined compressive strength(UCS).The results reveal that the flow value increases with the water content and decreases with the binder *** the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and viscosity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified *** rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is contrary to anti-scour *** unconfined compressive strength after solidification reduces as the water content increases and binder content decreases.A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference.

关键词： scour repair and protection solidified soil pumpability strength flow properties anti-scour performance

Metal-to-insulator transition in platinum group compounds

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Rare Metals 2024年第8期43卷 3460-3474页

作者： Yu-Xuan Xia jian-Gang He Nuo-Fu chen Ji-Kun chen School of New Energy North China Electric Power UniversityBeijing102206China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China Key Laboratory of Advanced Materials and Devices for PostMoore Chips(Ministry of Education) School of Materials Science and EngineeringJniversity of Science and Technology BeijingBeijing 100083China

The metal-to-insulator transition(MIT) as usually achieved in 3d-orbital transitional metal(TM) compounds opens up a new paradigm in correlated electronics via triggering abrupt variations in their transportation *** to such 3d-orbital TM compounds,the MIT within the platinum group(Pg) element compounds based on the 4d-and 5d-orbital configurations is more complicated,owing to their elevation in the spinorbit coupling and meanwhile weakened intra-atomic Coulomb *** brings in a new freedom to regulate the balance in their metallic or semiconductive orbital configurations,while their MIT properties can be potentially combined with their spintronic properties to enable new electronic ***,we review the electronic transport and MIT behaviors within the existing family of Pg-containing compounds,particularly those showing first-order MIT behaviors that can be useful in correlated *** is also hoped that summarizing the presently reported Pg-containing MIT compounds will lead to the discovery of more new material families and/or new mechanisms associated with the Pg-containing compounds showing MIT properties.

关键词： Metal-to-insulator transition Platinum group compounds Electron correlation Spin-orbital coupling

A symmetric substructuring method for analyzing the natural frequencies of conical origami structures

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 203-210页

作者： chenhao Lu Yao chen Weiying Fan jian Feng Pooya Sareh Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education and National Prestress Engineering Research CenterSoutheast UniversityNanjing 211189China School of Engineering University of LiverpoolLiverpool L693BXUnited Kingdom Creative Design Engineering Lab(Cdel) School of EngineeringNewcastle UniversityNewcastle upon Tyne NE17RUUnited Kingdom Escuela Técnica Superior de Ingeniería y Diseño Industrial Universidad Politécnica de Madrid(UPM)Madrid 28012Spain

Conical origami structures are characterized by their substantial out-of-plane stiffness and *** investigations have commonly focused on the static characteristics of these lightweight ***,the efficient analysis of the natural vibrations of these structures is pivotal for designing conicalorigami structures with programmable stiffness and *** this paper,we propose a novel method to analyzethe natural vibrations of such structures by combining a symmetric substructuring method(SSM)and a gener-alized eigenvalue *** exploits the inherent symmetry of the structure to decompose it into a finiteset of repetitive *** doing so,we reduce the dimensions of matrices and improve computationalefficiency by adopting the stiffness and mass matrices of the substructures in the generalized eigenvalue *** element simulations of pin-jointed models are used to validate the computational results of the ***,the parametric analysis of the structures demonstrates the influences of the number of seg-ments along the circumference and the radius of the cone on the structural mass and natural frequencies of ***,we present a comparison between six-fold and four-fold conical origami structures anddiscuss the influence of various geometric parameters on their natural *** study provides a strategyfor efficiently analyzing the natural vibration of symmetric origami structures and has the potential to contributeto the efficient design and customization of origami metastructures with programmable stiffness.

关键词： Natural structural vibration Origami design Group theory Symmetric substructuring method(SSM) Generalized eigenvalue analysis

Geochemical Characteristics and Development Significances of Constant and Trace Elements from Coalbed Methane Co-Produced Water:A Case Study of the Shizhuangnan Block,the Southern Qinshui Basin

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Journal of Earth Science 2024年第1期35卷 51-61页

作者： Yang Li Shuheng Tang jian chen Songhang Zhang Zhaodong Xi Key Laboratory of Universities in Anhui Province for Prevention of Mine Geological Disasters Anhui University of Science and TechnologyHuainan 232001China School of Earth and Environment Anhui University of Science and TechnologyHuainan 232001China National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing 102249China School of Energy Resource China University of GeosciencesBeijing 100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationBeijing 100083China Key Laboratory of Strategy Evaluation for Shale Gas Ministry of Land and ResourcesBeijing 100083China

As an unconventional natural gas resource,coalbed methane(CBM)development releases a large amount of CBM wells co-produced *** characteristics of the co-produced water provide an essential foundation for the production dynamics of CBM reservoirs if the impacts of fracturing fluids and other aquifers can be *** the Shizhuangnan Block of the southern Qinshui Basin,constant and trace elements in CBM co-produced water from the wellheads were collected and determined,which is applied to assess water source,fracturing fluid effect,and CBM *** on principle component analysis and hierarchical clustering analysis,the water samples are divided into four *** suggests that different characteristics affected by water-rock interaction,reservoir environment,aquifer recharge,and hydraulic fracturing result in the various ratios of Na^(+)/Cl^(-),alkalinity(HCO_(3)^(-)+CO_(3)^(2-))/Cl^(-)and other specific ***,Cl^(-)is selected as a dividing line for complete fracturing fluid flow back,associated with organic-bound chlorine complexes in the original coal seam *** to constant elements,there is a significant correlation between Li and Sr concentrations and CBM productivity,so templates regarding trace elements can be used to distinguish various sources of the co-produced water.

关键词： coalbad methane CBM co-produced water hydraulic fracturing Qinshui Basin