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Collapse in crystalline structure and decline in catalytic activity of pt nanoparticles on reducing particle size to 1 nm

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： L.H.LI X.L.Deng Z.f.Yang W.D.Sun S.B.Chen p.f.liu Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of Science China University of Mining and Technology

Shepan Island large ancient underground quarry is located in Zhejiang province,eastern *** a period of 800 years,the island has been experiencing large-scale quarrying activities since the Southern Song Dynasty(AD 1127-1279).Nowadays,many large ancient underground cavern groups have been *** ancient cultural relics,these caverns enjoy a high tourism reputation and other *** present,most of these caverns still maintain their ***,different levels of deformation and failure also occurred in some *** quarrying method,structures of the caverns,structure and quality of the surrounding rock mass were analyzed by using field investigations and laboratory *** on above research results,it is concluded that unique quarrying methods and cavern structures account for the long-term stability of these *** most important factor is the good quality of the rock mass,which implies that a good engineering geological condition is the fundamental reason for the long-term stability of Shepan Island ancient quarry caverns.

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Collapse in crystalline structure and decline in catalytic a...

分子亚型参考标准的差异影响基于人工智能的动态增强MRI乳腺癌分型

第九届全国氢能学术会议

作者： Y.B.Sun,L.Zhuang,J.T.Lu,X.L.Hong,p.f.liu Wuhan University,China

platinum has been playing a vital role in heterogeneous catalysis,especially for low temperature fuel *** maximize pt utilization,nanoparticles are usually applied,with the particle size expected to be as small as ***,the particle-size dependent catalytic activity of pt,determined by the interplay of surface geometric and electronic factors, is not quite straightforward in the range of a few *** CO oxidation,methanol

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国际医学放射学杂志 2023年第3期 356-357页

作者： Y.Ji H.M.Whitney H.Li p.f.liu M.L.Giger X.N.Zhang 陈薪伊

摘要根据免疫组化（IHC）染色或包括Ki-67在内的St Gallen标准，乳腺癌可被分为不同的Luminal分子亚型。目的描述分子亚型，研究IHC和St Gallen分子亚型参考标准不

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Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.J.Song f.liu State Key Laboratory of Solidification processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CpfE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

Electron kinetic effects in back-stimulated Raman scattering bursts driven by broadband laser pulses

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Matter and Radiation at Extremes 2024年第4期9卷 54-67页

作者： Q.K.liu L.Deng Q.Wang X.Zhang f.Q.Meng Y.p.Wang Y.Q.Gao H.B.Cai S.p.Zhu Graduate School China Academy of Engineering PhysicsBeijing 100088China Institute of Applied physics and Computational Mathematics Beijing 100094China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Shanghai Institute of Laser plasma Shanghai 201800China HEDpS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China School of physics Zhejiang UniversityHangzhou 310027China

We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell *** bursts occur during the nonlinear stage,causing reflectivity spikes and generating large numbers of hot ***-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity *** the simplified model,we isolate and characterize the spectrum of electron plasma *** spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asymmetry in the spectrum is *** asymmetry is amplified and transferred to electron phase space by high-intensity broadband laser pulses,leading to violent vortex-merging and generation of hot *** proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst *** demonstrate that kinetic effects profoundly influence the BSRS evolution driven by broadband lasers.

关键词： scattering kinetic simplified

Temperature-dependent thermal conductivity and fuel performance of UN-UO_(2) and UN-X-UO_(2)(X=Mo,W)composite nuclear fuels by finite element modeling

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Journal of Materiomics 2024年第4期10卷 937-946页

作者： faris Sweidan Diogo Ribeiro Costa Huan liu pär Olsson KTH Royal Institute of Technology Nuclear EngineeringStockholm10691Sweden Westinghouse Electric Sweden AB Västerås72163Sweden

The temperature-dependent effective thermal conductivity of UN-X-UO_(2)(X=Mo,W)nuclear fuel composite was *** the experimental design,the thermal conductivity was calculated using finite Element Modeling(fEM),and compared with analytical models for 10%,30%,50%,and 70%(in mass)uncoated/coated UN microspheres in a UO2 *** fEM results show an increase in the fuel thermal conductivity as the mass fraction of the UN microspheres increases from 1.2 to 4.6 times the UO2 reference at 2,000 *** results from analytical models agree with the thermal conductivity estimated by *** results also show that Mo and W coatings have similar thermal behaviors,and the coating thickness influences the thermal conductivity of the *** higher weight fractions,the thermal conductivity of the fuel composite at room temperature is substantially influenced by the high thermal conductivity coatings approaching that of ***,the thermal conductivity from fEM was used in the fuel thermal performance evaluation during LWR normal operation to calculate the maximum centerline *** results show a significant decrease in the fuel maximum centerline temperature ranging from−94 K for 10% UN to−414 K for 70%(in mass)UN compared to UO2 under the same operating conditions.

关键词： Accident tolerant fuel UN-X-UO_(2) Composite nuclear fuel Thermal conductivity finite element modeling Thermal performance

On the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： f.J.GARCíA-GARCíA p.fARINAS-ALVARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULf)and the purely turbulent component(pTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

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flame Structure of Methane and Kerosene Combustion with a Compact Concave flame-Holder using the LES-pdf Method

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Journal of Thermal Science 2024年第1期33卷 222-234页

作者： WANG fang WANG Yunfan WEI Guanyi liu Denghuan JIN Jie JONES p.William School of Energy and power Engineering Beihang UniversityBeijingBeijing 100191China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Compact flame-holders for afterburners are an increasing requirement for modern aero ***,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex turbulence,combustion,and spray coupling in modern *** this work,the LES-pdf and stochastic fields-Lagrangian particle spray methods are used to investigate methane and aviation kerosene combustion structures formed by new-type concave *** flow pattern,combustion mode,and flame structure of gaseous and liquid fuel around a concave flame-holder are analyzed,discussed,and compared with experimental *** reveal that the flame stability of a concave flame-holder is better than that of the non-concave ***,when using liquid fuel,the concave flame-holder forms a stable and compact *** results suggest concave flame-holders are a promising design for compact afterburners.

关键词： concave structure flame-holder LES-pdf spray combustion flame structure AECSC

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Artificial ground freezing of underground mines in cold regions using thermosyphons with air insulation

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International Journal of Mining Science and Technology 2024年第5期34卷 643-654页

作者： Ahmad f.Zueter Mohammad Zolfagharroshan Navid Bahrani Agus p.Sasmito Department of Civil and Resource Engineering Dalhousie UniversityHalifax B3H4R2Canada Department of Mining Engineering McGill UniversityMontreal H3A0E8Canada

Current practice of underground artificial ground freezing(AGf)typically involves huge refrigeration systems of large economic and environmental *** this study,a novel AGf technique is proposed deploying available cold wind in cold *** is achieved by a static heat transfer device called thermosyphon equipped with an air insulation layer.A refrigeration unit can be optionally integrated to meet additional cooling *** introduction of air insulation isolates the thermosyphon from ground zones where freezing is not needed,resulting in:(1)steering the cooling resources(cold wind or refrigeration)towards zones of interest;and(2)minimizing refrigeration *** design is demonstrated using well-validated mathematical models from our previous work based on two-phase enthalpy method of the ground coupled with a thermal resistance network for the *** Canadian mines are considered:the Cigar Lake Mine and the Giant *** results show that our proposed design can speed the freezing time by 30%at the Giant Mine and by two months at the Cigar Lake ***,a cooling load of 2.4 GWh can be saved at the Cigar Lake ***,this study provides mining practitioners with sustainable solutions of underground AGf.

关键词： Artificial ground freezing Underground mining Sustainable mining Thermosyphon Air insulation Cold regions

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