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Yield ratio of hypertriton to light nuclei in heavy-ion collisions from √sNN=4.9 GeV to 2.76 TeV

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Chinese Physics C 2020年第11期44卷 86-93页

作者：邵天浩陈金辉 Che Ming Ko 孙开佳许长补 Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Institute of Applied Physics Chinese Academy of ScienceShanghai 201800China University of Chinese Academy of Science Beijing 100049China Cyclotron Institute and Department of Physics and Astronomy Texas A&M UniversityCollege StationTexas 77843USA Brookhaven National Laboratory UptonNew York 11973USA

We argue that the difference in the yield ratio S3=NΛ3H/NΛ/N3He/Np measured in Au+Au collisions at √sNN=200 GeV and in Pb-Pb collisions at √sNN=2.76 TeV is mainly owing to the different treatment of the weak decay contribution to the proton yield in the Au+Au collisions at √sNN=200 GeV.We then use the coalescence model to extract from measured S3 the information about the Λ and nucleon density fluctuations at the kinetic freeze-out of heavy-ion collisions.We also show,using available experimental data,that the yield ratio S2=NΛ3H/NΛNd is a more promising observable than S3 for probing the local baryon-strangeness correlation in the produced medium.

关键词： baryon-strangeness correlation hypernuclei QCD phase transition coalescence

Twinning behavior of hot extruded AZ31 hexagonal prisms during uniaxial compression

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Journal of Magnesium and Alloys 2019年第1期7卷 90-97页

作者： Y.R.Zhao L.L.Chang J.Guo Y.P.Jin School of Materials Science and Engineering Shandong UniversityJinanShandong 250061China Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

Hot-extruded magnesium alloy AZ31 bar was cut into hexagonal prisms and then compressed at room temperature with the loading direction parallel to the extrusion direction(ED)or perpendicular to ED.The effective stress and strain evolution at center and corner region of the hexagonal prisms was simulated by using DEFORM 3D,while microstructure evolution was characterized by electron backscatter diffraction(EBSD).Relationship between twinning behavior and stress-strain evolution during compression at room temperature was studied.The results indicated that the compressive stress and strain levels at central region of hexagonal prisms were lower than those at the corner parts.EBSD examination revealed that{10-12}twins activate during the compression and the volume fraction of twins at corner parts were less than that at the central parts,which was attributed to twin thickening and coalescence behaviors.Meanwhile,the EBSD map indicated that the arise of{10-11}contraction twins and{10-11}-{10-12}double twins in compressed samples,especially in the corner region with loading axis perpendicular to ED,which were considered to be related to the high stress level at corner region.The dislocation slips led to low-angle boundaries in LA⊥ED and LA//ED.

关键词： Magnesium alloy Simulation Microstructure Twinning coalescence

Erasable/Inerasable L1 Transfer in Interlanguage Phonology:An Optimality Theory Analysis of/aʊn/and Sentence Stress in Chinese Learners of English

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Contemporary Social Sciences 2022年第5期7卷 139-155页

作者： Fan Yi School of Foreign Languages Peking University.School of Foreign LanguagesPeking UniversityBeijing100871China

The areas affected by the L1 transfer to L2,such as phonotactics and stress,appear to have different degrees of erasability through training and practice.This paper attempts a theoretical analysis to account for empirical observations of L1 transfer in diphthong-coda coalescence and in sentence stress for Chinese learners of English in an American accent training course.Using the framework and tableau method of Optimality Theory(Prince and Smolensky 1993),the phonological paradigm that views languages’differences as symptomatic of differences in rankings of a set of universal violable constraints,this paper posits the underlying ranking at work in(a)the segmental case where[aŋ]is the observed output for/aʊn/;(b)the suprasegmental case where no stress contrast is observed for a pair of phonologically similar sentences with contrastive stress.It is argued that,in the segmental case,the coalescence of the second vowel of a diphthong with an alveolar nasal coda results from the high ranking of markedness constraints,including Complex Syllable;and in the suprasegmental case,sentence stress is greatly affected by changes in the ranking of the constraint culminativity.Aside from shedding light on the understudied issue of diphthong-coda coalescence,this research also contributes to the discussion of the comparative erasability of L1 transfer for the two areas and demonstrates how a deduction-based theoretical method may actually have practical implications for guiding the design of L2 teaching methodology of English pronunciation as well as for promoting native English speakers’clearer understanding of Chinese learners of English on the global stage.

关键词： Chinese ESL learners coalescence diphthong second language acquisition sentence stress Optimality Theory

Shock-timing experiments in polystyrene target

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Chinese Optics Letters 2010年第12期8卷 1142-1143页

作者：舒桦傅思祖黄秀光贾果周华珍吴江叶君建顾援 Shanghai Institute of Laser Plasmas

Direct-drive and indirect-drive inertial confinement fusion （ICF） targets use temporally shaped drive pulses to optimize target performance. The timing of multiple shock waves is crucial to the performance of ICF ignition targets. Velocity interferometer system for any refiector （VISAR） is the principal diagnostic tool for shock-timing experiments. We present velocity measurements from the shock waves in polystyrene targets driven by two 200-ps pulses separated by 1–2 ns. These pulses drive two shock waves that coalescence in the target. coalescence time and transit times are observed by VISAR.

关键词： coalescence Polystyrenes Shock waves Velocity measurement Waves

Influence of Fresh Water on Microbubble Generation in an Airlift Column Applied to Aquaculture: Extraction Capacity

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Open Journal of Applied Sciences 2022年第11期12卷 1809-1823页

作者： Djimako Bongo Nekoulnang Djetounako Clarisse Edith Kadjangaba Salif Gaye Jean-Yves Champagne Higher Normal School of Technology of Sarh Sarh Chad Paleontology Department National Research Center for Development of N’djamena N’djamena Chad Faculty of Sciences and Techniques University of Doba Doba Chad LME Materials and Energetics Laboratory University Institute of Technology Thiès Senegal Laboratory of Fluid Mechanics and Acoustics INSA-Lyon Lyon France

Bubble flows consist a liquid phase and a gaseous phase dispersed as bubbles. They occur in nature and in many industrial applications, such as oil transportation in pipelines and steam generators for power generation. Due to large difference in density between gas and liquid, the flottability force causes bubbles to rise, which in turn can generate overall motion and agitation in liquid. This use of gravity as a flow driver, which is specific to disperse phase systems, is used in process engineering (bubble columns and gasosiphon) to sparingly promote mixing and exchange between gas and liquid. In many applications, bubbles are used to agitate a liquid in order to promote mixing and transfers. This work is devoted to study of hydrodynamics of a bubble column. Experimentally, we have determined properties fluctuations of velocities inside the aquarium of rising homogeneous bubbles for different bubble sizes and vacuum rates. The interfacial area between gas and liquid phase is a crucial factor for mass transfer in bubble columns. The molecular exchange between a given volume of gas and water can be enhanced by formation of smaller bubbles, leading to a larger gas-liquid interface. This work presents the various physical phenomena that apply to bubbles, as well as associated dimensionless numbers. A state art of Micro-Bubble Generators (MBG) is then presented, presenting systems using various phenomena such as cavitation, electrolysis, or shear.

关键词： Vacuum Airlift Column MIBC Casein Turbidity Surfactant coalescence

Solvent Extraction in Hydrometallurgy: Present and Future

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Tsinghua Science and Technology 2006年第2期11卷 137-152页

作者： Gordon M. Ritcey G. M. Ritcey and Associates Inc. Ottawa Canada

During the past 10 years, there have been incremental advances in the application of solvent extraction to process hydrometallurgy. The most cited areas in the literature include chemistry, chemical engineering, pilot plants, and plant operation. Within these areas, there were considerable interest in synergism, diluents, degradation, contactors, surfactants, hydrometallurgical applications, environmental and secondary applications, and health and safety. The summary to the present is followed by a prediction for the future in the above areas of interest. These include the use of speciation; improved understanding of the role of surfactants on the system; optimization through modelling, pilot plants, and contactor selection; improvements in plant operation; further new applications; and plant safety. The review has indicated that considerable knowledge is now available to optimize and improve on process design and plant applications.

关键词： chemical engineering coalescence degradation diluents dispersion droplet size electrostaticpseudoliquid membrane environmental and secondary recovery hydrometallurgical applications

Numerical study of influence of hydraulic fracturing on fluid flow in natural fractures

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Petroleum 2019年第3期5卷 321-328页

作者： Jaber Taheri-Shakib Amir Ghaderi Mohammad Amin Sharif Nik Research Institute of Petroleum Industry Department of Research and Technology of the Rock and Fluid ReservoirsIran National Iranian South Oil Company Iran Research Institute of Petroleum Industry Department of Research and Technology of the Geomechanic ReservoirsIran

The hydraulic fracturing operation is highly complex in fractured reservoirs.The fundamental key to a successful operation is processing and analysis of the propagation of hydraulic fracturing in a natural fracture network.In this paper,the hydraulic fracturing process is evaluated in a fractured reservoir in southwest Iran.The developing process of induced fracture in a natural fracture network is analysed by the Distinct Element Method(DEM).After determining the fluid flow regime in the natural fractures of the reservoir,hydraulic fracturing is applied along different lengths of the reservoir and in each range,the production rate is checked.Fluid flow in natural fractures after the hydraulic fracturing operation is shown and evaluated in order to evaluate the induced fracture effectiveness in enhancing fluid flow regimes in the reservoir.The reverse suction phenomenon which causes changes in the fluid flow pattern in fractures and will thus affect the production rate is also studied in this paper.Fracture coalescence will cause the induction of natural fractures to hydraulically fracture without their intersection;this is one of the significant parameters in hydraulic fracturing in naturally fractured reservoirs which is also discussed in detail.This paper can present valuable information on fluid flow analysis before and after applying hydraulic fracturing in a fractured reservoir and solve some essential ambiguities in this area.

关键词： Hydraulic fracture Fractured reservoirs Production coalescence Fluid flow

Demulsification of Water in oil Emulsion by Using Porous Glass Membrane

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High Technology Letters 1999年第2期5卷 98-102页

作者：孙德智 Dept. of Applied Chemistry Harbin Institute of Technology Harbin 150001 China

The hydrophilic porous glass membranes were used to demulsify water in oil emulsion, liquid membrane and demulsification efficiency can reach more than 96 percent. Effects of pore size of the membrane, transmembrane pressure and volumetric ratio of oil phase to internal aqueous phase in the emulsion on demulsification were investigated. Correspondingly, effect of transmembrane pressure on permeation flux of the droplets was also studied.

关键词： Porous glass membrane Emulsion liqurd membrane Demulsification coalescence

Numerical Study of Surfactant-Laden Drop-Drop Interactions

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Communications in Computational Physics 2011年第7期10卷 453-473页

作者： Jian-Jun Xu Zhilin Li John Lowengrub Hongkai Zhao School of Mathematical and Computational Sciences Xiangtan UniversityXiangtanHunan 411105China Department of Mathematics North Carolina State UniversityRaleighNC27695USA Department of Mathematics University of California IrvineIrvineCA92697USA

In this paper,we numerically investigate the effects of surfactant on dropdrop interactions in a 2D shear flow using a coupled level-set and immersed interface approach proposed in(Xu et al.,J.Comput.Phys.,212(2006),590–616).We find that surfactant plays a critical and nontrivial role in drop-drop interactions.In particular,we find that the minimum distance between the drops is a non-monotone function of the surfactant coverage and Capillary number.This non-monotonic behavior,which does not occur for clean drops,is found to be due to the presence of Marangoni forces along the drop interfaces.This suggests that there are non-monotonic conditions for coalescence of surfactant-laden drops,as observed in recent experiments of Leal and co-workers.Although our study is two-dimensional,we believe that drop-drop interactions in three-dimensional flows should be qualitatively similar as the Maragoni forces in the near contact region in 3D should have a similar effect.

关键词： Surfactants drops coalescence surface tension Marangoni effect level-set method immersed interface method Stokes flow