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Investigations of Water Flow Behaviors Induced by.Local Temperature Variations through a Single rough Fracture for the Enhanced Geothermal Sy.tems

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Journal of Thermal Science 2024年第3期33卷 1055-1064页

作者： LI Jiawei y. Lin Department of Energy.and Power Engineering Tsinghua UniversityBeijing100084China School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

In recent y.ars,Enhanced Geothermal Sy.tem(EGS)technologies have been applied to the geothermal resources production in the Hot Dry.rock(HDr).The core of EGS technologies is to adopt hy.raulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hy.raulic fracturing and heat *** paper investigates the characteristics of water flow behaviors through a single rough fracture under different temperature and pressure conditions.A single fracture model with rough fracture surfaces is constructed and then characterized,and influences of the anisotropic factor on the average tortuosity.and frictional resistance coefficient of water flow through a single fracture with rough surfaces have been compared and *** consideration of other impacting factors(temperature,pressure,fracture roughness),the impact of mass flow rate has also been *** simulation results present that changes of average tortuosity.for water flow through a single rough facture are mainly.affected by.*** can be observed that higher temperature leads to larger average tortuosity.but the frictional resistance coefficient shows an opposite *** for pressure conditions,it is found that effects of pressure on average tortuosity.and frictional resistance coefficient is very.small,which can be neglected under high pressure ***,the average tortuosity.shows a progressively.linear relationship with the mass flow *** the contrary.the frictional resistance coefficient has a negative relationship with the mass flow *** is revealed that when the mass flow rate reaches a critical point,the influences of temperature on the frictional resistance coefficient will be *** of single rough fractures with different anisotropic factors show that values of average tortuosity.and frictional resistance coefficient have positive relationships with the increase

关键词： single rough fracture tortuosity frictional resistance enhanced geothermal sy.tem

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Path-Dependent Progressive Failure Analy.is for 3D-Printed Continuous Carbon Fibre reinforced Composites

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 84-93页

作者： y.an Chen Lin y. School of Sy.tem Design and Intelligent Manufacturing(SDIM) Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key.Laboratory.of Intelligent Manufacturing for Continuous Carbon Fibre reinforced Composites Southern University of Science and TechnologyShenzhen 518055China

In order to predict the damage behaviours of 3D-printed continuous carbon fibre(CCF)reinforced composites,when additional short carbon fibre(SCF)composite components are employ.d for continuous printing or special functionality.a novel path-dependent progressive failure(PDPF)numerical approach is ***,a progressive failure model using Hashin failure criteria with continuum damage mechanics to account for the damage initiation and evaluation of 3D-printed CCF reinforced poly.mide(PA)composites is developed,based on actual fibre placement trajectories with phy.ical measurements of 3D-printed CCF/PA ***,an elastic-plastic model is employ.d to predict the plastic damage behaviours of SCF/PA ***,the accuracy.of the PDPF model was validated so as to study.3D-printed CCF/PA composites with either negative Poisson's ratio or high *** results demonstrate that the proposed PDPF model can achieve higher prediction accuracies in mechanical properties of these 3D-printed CCF/PA *** analy.es show that the stress distribution is generally.aggregated in the CCF areas along the fibre placement paths,and the shear damage and matrix tensile/compressive damage are the key.damage *** study.provides a new approach with valuable information for characterising complex 3D-printed continuous fibre-matrix composites with variable mechanical properties and multiple constituents.

关键词： 3D printing Continuous carbon fibre Modelling Energy.absorption Negative Poisson's ratio

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A modified stochastic model for LS+Ar hy.rid method and its application in polar motion short-term prediction

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Geodesy.and Geody.amics 2024年第1期15卷 100-105页

作者： Fei y. y.nbin y.an State Key.Laboratory.of Geodesy.and Earth's Dy.amics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China BeiDou High-precision Satellite Navigation and Location Service Hunan Engineering research Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China Hunan Continuously.Operating reference Stations(HNCOrS)Data Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China

Short-term(up to 30 day.)predictions of Earth rotation Parameters(ErPs)such as Polar Motion(PM:PMX and PMy.play.an essential role in real-time applications related to high-precision reference frame ***,least squares(LS)+auto-regressive(Ar)hy.rid method is one of the main techniques of PM ***,the weighted LS+Ar hy.rid method performs well for PM short-term ***,the corresponding covariance information of LS fitting residuals deserves further exploration in the Ar *** this study.we have derived a modified stochastic model for the LS+Ar hy.rid method,namely.the weighted LS+weighted Ar hy.rid *** using the PM data products of IErS EOP 14 C04,the numerical results indicate that for PM short-term forecasting,the proposed weighted LS+weighted Ar hy.rid method shows an advantage over both the LS+Ar hy.rid method and the weighted LS+Ar hy.rid *** to the mean absolute errors(MAEs)of PMX/PMy.sho rt-term prediction of the LS+Ar hy.rid method and the weighted LS+Ar hy.rid method,the weighted LS+weighted Ar hy.rid method shows average improvements of 6.61%/12.08%and 0.24%/11.65%,***,for the slopes of the linear regression lines fitted to the errors of each method,the growth of the prediction error of the proposed method is slower than that of the other two methods.

关键词： Stochastic model LS+Ar Short-term prediction The earth rotation parameter(ErP) Observation model

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In-depth insights into critical role of aromatic C（sp2）–H on Li+ storage

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rare Metals 2024年第10期43卷 5449-5452页

作者： Ling Qin y. Zhou China-UK Low Carbon College Shanghai Jiao Tong University

The development of high-sloping-capacity.carbons enables the creation of high-power lithium-ion batteries and capacitors （LIBs/LICs）.Among the various heteroatomdoped carbon materials,hy.rogen-rich carbon appears to be a promising candidate due to its facile sy.thesis and high capacity.for Li+***,conclusive data are still lacking to elucidate the fundamental function of the hy.rogen-terminated groups （C-H configuration） in Li+*** and his co-workers have utilized an ion-cataly.ed self-template method to sy.thesize the hy.rogen-rich carbon nanoribbon （HCNr） with high specific and rate *** HCNr?s Li+storage mechanism is clarified by.the use of in situ spectroscopy.methods,which reveals that the sp2-hy.ridization of the

关键词： Aromatization

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A novel relationship between elastic modulus and void ratio associated with principal stress for coral calcareous sand

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Journal of rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1033-1048页

作者： ran Gao Jianhong y. State Key.Laboratory.of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University.of Chinese Academy.of Sciences Beijing100049China

Elastic moduli,*** modulus G and bulk modulus K,are important parameters of geotechnical materials,which are not only.the indices for the evaluation of the deformation ability.of soils but also the important basic parameters for the development of the constitutive models of geotechnical *** this study.a series of triaxial loading-unloading-reloading shear tests and isotropic loading-unloadingreloading tests are conducted to study.several ty.ical mechanical properties of coral calcareous sand(CCS),and the void ratio evolution during loading,unloading and *** test results show that the stress-strain curves during multiple unloading processes are almost parallel,and their slopes are much greater than the deformation modulus at the initial stage of *** relationship between the confining pressure and the volumetric strain can be defined approximately.by.a hy.erbolic equation under the condition of monotonic loading of confining *** the condition of confining pressure unloading,the evolution of void ratio is linear in the e-lnp0 plane,and these lines are a series of almost parallel lines if there are multiple processes of *** on the experimental results,it is found that the modified Hardin formulae for the elastic modulus estimation have a significant deviation from the tested values for *** on the experimental results,it is proposed that the elastic modulus of soils should be determined by.the intersection line of two spatial surfaces in the G/K-e-p’/pa space(pa:atmosphere pressure).“y. formulation”is further proposed for the estimation of the elastic modulus of *** new estimation formulation for soil elastic modulus would provide a new method to accurately.describe the mechanical behavior of granular soils.

关键词： Coral calcareous sand(CCS) Elastic shear modulus Elastic bulk modulus Triaxial test Estimation formulation y. formulation

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Global precipitation change during the Holocene:a combination of records and simulations

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Frontiers of Earth Science 2024年第1期18卷 112-126页

作者： Wangting y. y. LI Key.Laboratory.of Western China᾽s Environmental Sy.tems(Ministry.of Education) College of Earth and Environmental SciencesCenter for Hydrologic Cycle and Water Resources in Arid RegionLanzhou UniversityLanzhou 730000China

Precipitation can shape our climate both in the present and the *** though we have made significant advances in study.ng the mechanisms of millennial-scale climate changes through high-resolution records,we still cannot quantitatively.characterize the global spatiotemporal precipitation variations within the ***,we developed a new approach to integrating data from 349 globally.distributed records and climate models to reconstruct regional and global precipitation patterns over the last 12000 *** results reveal that precipitation reconstructions can be divided into monsoon-driven and westerly.driven *** results suggest that an arid climate was experienced in the late glacial and early.Holocene epoch(~12−7.4 cal ka BP),attaining a middle Holocene optimum(~7.4−3.5 cal ka BP),and drier after the middle *** to our reconstructions,the global precipitation reconstruction increased from the early.Holocene until 3.8 cal ka BP and then subsequently.*** addition,our reconstructions better reproduce the low-frequency.events and extreme precipitation at the millennial scale in the hemispheres,but the performance of the reconstructions in the equatorial Pacific and the Southern Hemisphere of Africa and the Americas is *** resolution of the record and the simulation capability.of the climate model remain important means to improve our understanding of past climate change.

关键词： Holocene equatorial glacial

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Improved LS+MAr hy.rid method to UT1-UTC ultra-short-term prediction by.using first-order-difference UT1-UTC

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Geodesy.and Geody.amics 2024年第4期15卷 379-385页

作者： Fei y. y.nbin y.an BeiDou High-precision Satellite Navigation and Location Service Hunan Engineering research Center Hunan Institute of Geomatics Sciences and TechnologyChangsha410007China State Key.Laboratory.of Geodesy.and Earth's Dy.amics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430077China HNCOrS Data Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China

Accurate ultra-short-term prediction of the Earth rotation parameters(ErP)holds paramount impor-tance for real-time applications,particularly.in reference frame *** them,diurnal rota-tion(UT1-UTC)which cannot be directly.estimated through Global Navigation Satellite Sy.tem(GNSS)techniques,significantly.affects the rapid and ultra-rapid orbit determination of GNsS ***-ently.the traditional LS(least squares)+Ar(autoregressive)and LS+MAr(multivariate autoregressive)hy.rid methods stand as primary.approaches for UT1-UTC ultra-short-term predictions(1-10 day.).The LS+MAr hy.rid method relies on the UT1-UTC and LOD(length of day.***,the correlation between LOD and first-order-difference UT1-UTC is stronger than that between LOD and *** light of this,and with the aid of the first-order-difference UT1-UTC,we propose an enhanced LS+MAr hy.rid method to UT1-UTC ultra-short-term *** using the UT1-UTC and LOD data series of the IErS(International Earth rotation and reference Sy.tems Service)EOP 14 C04 product,we conducted a thorough analy.is and evaluation of the improved method's prediction performance compared to the traditional LS+Ar and LS+MAr hy.rid *** to the numerical results over more than 210 day.,they.demonstrate that,when considering the correlation information between the LoD and the first-order-difference UT1-UTC,the mean absolute errors(MAEs)of the improved LS+MAr hy.rid method range from 21 to 934μs in 1-10 day. *** comparison to the traditional LS+Ar hy.rid method,the MAEs show a reduction of 7-53μs in 1-10 day. predictions,with corresponding improvement percentages ranging from 1 to 28%.Similarly.when compared to the traditional LS+MAr hy.rid method,the MAEs have a reduction of 5-42μs in 1-10 day. predictions,with corresponding improvement percentages ranging from 4-20%.Additionally.when aided by.GNSS-derived LOD data series,the MAEs of improved LS+MAr hy.rid method experience further

关键词： UT1-UTCultra-short-termprediction rapidandultra-rapidproducts LS+Ar and LS+MAr Correlation First-order-differenceUT1-UTC

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General formalism for dirty.extreme-mass-ratio inspirals

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Science China(Phy.ics,Mechanics & Astronomy. 2024年第7期67卷 22-29页

作者： y. Jiang Wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy.and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Phy.ics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science Center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity.are important applications of extreme-mass-ratio inspirals(EMrIs).There is still a challenge to efficiently.describe various“dirty.impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study.we find the inherent linearity.of the asy.ptotic solution of the inhomogeneous Teukolsky.*** the basis of this property.we completely.decouple the factors of the perturber and the background spacetime in the energy.fluxes and *** the new decoupling form,the waveforms of EMrIs with non-geodesic motion in Kerr spacetime can be conveniently.*** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky.equation extreme-mass-ratio inspirals

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Effect of dissolved-oxy.en on the flotation behavior of py.ite at high altitude area

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International Journal of Minerals,Metallurgy.and Materials 2024年第10期31卷 2148-2158页

作者： y.n Miao Guangke y. Guofan Zhang School of Minerals Processing and Bio-engineering Central South UniversityChangsha 410083China

With the continuous development of mineral resources to high altitude areas,the study.of sulfide ore flotation in unconventional sy.tems has been *** is a consensus that moderate oxidation of sulfide ore is beneficial to flotation,but the specific suitable dissolved oxy.en value is inconclusive,and there are few studies on sulfide ore flotation under low dissolved oxy.en environment at high *** this paper,we designed and assembled an atmosphere simulation flotation equipment to simulate the flotation of py.ite at high altitude by.controlling the partial pressure of N_(2)/O_(2) and dissolved oxy.en under atmospheric conditions.X-ray.photoelectron spec-troscopy.XPS),atomic force microscope(AFM),Fourier transform infrared spectrometer(FT-Ir),UV-vis spectrophotometer,zeta po-tential,and contact angle measurements were used to reveal the effects of surface oxidation and agent adsorption on py.ite at high altitude(4600 m dissolved oxy.en(DO)=4.0 mg/L).The results of pure mineral flotation indicated that the high altitude and low dissolved oxy.gen environment is favorable for py.ite *** angle measurements and XPS analy.is showed that the high altitude atmosphere nslows down the oxidation of py.ite surface,facilitates S_(n)^(2-)/S^(0) production and enhances surface *** calcula-tions and zeta potential analy.is showed that the influence of atmosphere on the form of py.ite adsorption is small,and the different atmo-spheric conditions are consistent with dixanthogen electrochemical adsorption,with lower Zeta potential under high altitude atmosphere and significant potential shift after sodium isobuty. xanthate(SIBX)*** results of FT-Ir,UV-vis,and AFM analy.is showed that SIBX adsorbed more on the surface of py.ite under high altitude atmosphere and adsorbed on the surface in a mesh structure com-posed of column/*** results of the experimental study.revealed the reasons for the easy.flotation of sul

关键词： high altitude dissolved-oxy.en py.ite flotation oxidation

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Soft coarse-grained particle model for particle-fluid sy.tems

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Particuology 2024年第1期84卷 178-193页

作者： y.nhao y. Ji Xu Wei Ge State Key.Laboratory.of Multiphase Complex Sy.tems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy.for Green Manufacture Chinese Academy of SciencesBeijing100190China

By.modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid ***,a sy.tematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty.on the predictivity.of the *** this study.collisions between predefined particle groups are analy.ed to construct kernel functions for modeling the CGPs and then the model parameters are determined by.equating the statistical properties of the CGPs and the real particles in the phy.ical process *** approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

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