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International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1618-1626页

作者： Zexun Tang hongqi ye Xin Ma Kai Han Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China Cathode Material Research&Development Department Soundon New Energy Technology Co.Ltd.Xiangtan 411100China

Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric *** for the typical LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,the particle formation is significant for electrochemical properties of the *** this work,the structure,morphology,and electrochemical performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles and single crystals were systematically studied.A lower Ni^(2+)/Ni^(3+)molar ratio of 0.66 and a lower residual alkali content of 0.228wt%were achieved on the surface of the single *** addition,the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C(~12 mAh/g lower than that of the secondary particles)and enhanced the electrochemical stability,especially when cycled at 50℃ and in a wider electrochemical window(between 3.0 and 4.4 V ***+/Li).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) secondary particles were suitable for applications requiring high specific capacity,whereas single crystals exhibited better stability,indicating that they are more suitable for use in long life requested devices.

关键词： Ni-rich layered materials single crystal cathode micro-structure lithium-ion battery

Synthesis and characterization of PMMA/Al_2O_3 composite particles by in situ emulsion polymerization

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Particuology 2008年第3期6卷 207-213页

作者： Hui Liu hongqi ye Tianquan Lin Tao Zhou College of Chemistry and Chemical Engineering Central South University Changsha 410083 China

In order to improve its dispersibility, superfine alumina （A1203） was encapsulated with poly（methyl methacrylate）（PMMA） by in situ emulsion polymerization. It was found that only when the concentration of sodium dodecyl sulfate （SDS） was much higher than its critical micelle concentration, could PMMA/Al2O3 composite particles with high percentage of grafting （PG） be prepared. The same results were obtained between the experimental and stoichiometric amounts of tris（dodecylbenzenesulfonate） isopropoxide （NDZ）, indicating that single-molecule-layer adsorption had taken place between NDZ and Al2O3. Analysis using FTIR, TEM and XPS showed that PMMA/Al2O3 composite particles with core-shell structure had been successfully synthesized by in situ emulsion polymerization. Compared to Al2O3, thermal stability and dispersibility of the composite particles showed marked improvement.

关键词： PMMA Alumina Composite particle Encapsulation Dispersibility

The role of graphene coating on cordierite-supported Pd monolithic catalysts for low-temperature combustion of toluene

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Chinese Journal of Catalysis 2018年第5期39卷 946-954页

作者： Wen Li hongqi ye Gonggang Liu Hongchao Ji Yonghua Zhou Kai Han State Key Laboratory for Powder Metallurgy College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083HunanChina

In the present work,a Pd/graphene/cordierite(Pd/Gr/Cor)composite was prepared as a monolithic catalyst for low-temperature combustion of *** mainly focused on understanding the role of graphene coating through investigation of catalytic performance and adsorption behavior of the *** with the traditional Pd/Cor catalyst without graphene coating,Pd/Gr/Cor catalyst delivered much higher activity and stability for toluene catalytic combustion in both dry and moist *** electron microscopy(TEM)and hydrophobic characterizations indicated that graphene coating can considerably improve the dispersity of Pd nanoparticles and enhance the hydrophobicity of the cordierite *** adsorption behavior of the above two catalysts,including adsorption isothermal,adsorption kinetics,and adsorption thermodynamics were carefully *** simulation results indicated that a large amount of toluene was adsorbed on graphene surface through relatively weak interaction,whereas only a relatively small amount of toluene was adsorbed on Pd surface with strong *** adsorption thermal calculation indicated that the adsorption of toluene on graphene was a process with reduced entropy,indicating highly-ordered assembly of toluene molecular on *** is the significant concentration and affinity gap between graphene and Pd that ensures a simultaneously and rapid transfer of toluene during the reaction process.

关键词： Graphene coating Palladium Catalytic combustion Steam Adsorption

Clinical features, treatment strategies and outcomes of craniocervical junction arteriovenous fistulas: a cohort study of 193 patients

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Stroke & Vascular Neurology 2024年第1期9卷 18-29页

作者： Yongjie Ma Zihao Song Yinqing Wang Jiachen Wang Chuan He Guilin Li Peng Zhang Tao Hong Liyong Sun Peng Hu Ming ye hongqi Zhang Department of Neurosurgery Xuanwu Hospital Capital Medical University

Background Craniocervical junction(CCJ)arteriovenous fistulas(AVFs)are *** current treatment strategies for AVFs with different angioarchitecture need to be *** present study aimed to analyse the correlation between angioarchitecture and clinical characteristics,share our experience in treating this disease and identify risk factors associated with subarachnoid haemorrhage(SAH)and poor *** A total of 198 consecutive patients with CCJ AVFs from our neurosurgical centre were retrospectively *** patients were grouped according to their clinical manifestations,and their baseline clinical characteristics,angioarchitecture,treatment strategies and outcomes were *** The patients’median age was 56 years(IQR 47–62 years).The majority of patients were men with 166(83.8%)*** most common clinical manifestation was SAH(52.0%),followed by venous hypertensive myelopathy(VHM)(45.5%).The most common CCJ AVFs type was dural AVF,with 132(63.5%)*** most frequent fistula location was C-1(68.7%)and dural branch of vertebral artery(70.2%)was the most involved arterial feeders for *** most common direction of venous drainage was descending intradural drainage(40.9%),followed by ascending intradural drainage(36.5%).Microsurgery was the most common treatment strategy applied for 151(76.3%)patients,15(7.6%)patients were treated with interventional embolisation only,and 27(13.6%)received both interventional embolisation and microsurgical *** learning curve for microsurgery only was analysed by cumulative summation method,and the turning point was the 70th case,and blood loss in post-group was lower than that in pre-group(p=0.034).At the last follow-up,there were 155(78.3%)patients with favourable outcomes(modified Rankin Scale(mRS)<3).Age≥56(OR 2.038,95%CI 1.039 to 3.998,p=0.038),VHM as the clinical manifestation(OR 4.102,95%CI 2.108 to 7.982,p<0.001)and pretreatment mRS≥3(OR 3.127,95%CI 1.617 to 6.047,p<0

关键词： patients treatment hypertensive

A modified stochastic model for LS+AR hybrid method and its application in polar motion short-term prediction

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Geodesy and Geodynamics 2024年第1期15卷 100-105页

作者： Fei ye Yunbin Yuan State Key Laboratory of Geodesy and Earth's Dynamics 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 days)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)hybrid method is one of the main techniques of PM ***,the weighted LS+AR hybrid 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 hybrid method,namely the weighted LS+weighted AR hybrid *** 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 hybrid method shows an advantage over both the LS+AR hybrid method and the weighted LS+AR hybrid *** to the mean absolute errors(MAEs)of PMX/PMY sho rt-term prediction of the LS+AR hybrid method and the weighted LS+AR hybrid method,the weighted LS+weighted AR hybrid 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

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 ye 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 typical 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 hyperbolic 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).“ye 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 ye formulation

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 ye Yu LI Key Laboratory of Western China᾽s Environmental Systems(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 studying 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

Investigations of Water Flow Behaviors Induced by Local Temperature Variations through a Single Rough Fracture for the Enhanced Geothermal Systems

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

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

In recent years,Enhanced Geothermal System(EGS)technologies have been applied to the geothermal resources production in the Hot Dry Rock(HDR).The core of EGS technologies is to adopt hydraulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hydraulic 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 system

General formalism for dirty extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： ye 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 Physics 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 asymptotic 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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Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao ye Ji Xu Wei Ge State Key Laboratory of Multiphase Complex Systems 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 systematic 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 analyzed 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 physical 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