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speed of sound in Asymmetric Quark Matter

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原子核物理评论 2024年第1期41卷 587-593页

作者： XIE Chonglong HE Weibo LI Zhipeng SHAO Guoyun MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter School of PhysicsXi’an Jiaotong UniversityXi’an 710049China School of Physics Peking UniversityBeijing 100871China

The speed of sound in quark matter is an important physical quantity for studying the properties and the spacetime evolution of quark-gluon plasma(QGP).The behavior of the speed of sound with respect to temperature and density can reveal to some extent the equation of state and the phase structure of *** upon the previous studies on the speed of sound in symmetric quark matter,the formulae for calculating the speed of sound in asymmetric quark matter in the temperature-density space are further *** PNJL model is then used to calculate the dependence of the speed of sound on isospin ***,the relationship between the magnitude of the speed of sound and the QCD phase structure is discussed,and the regions where the acoustic equation fails are indicated under different physical *** is found that the boundary of vanishing sound speed in asymmetric quark matter is smaller than that in symmetric quark matter,meaning that the range where the acoustic wave equation fails in asymmetric quark matter is smaller than that in symmetric quark *** results also indicate that in most of the stable phase,the speed of sound in asymmetric quark matter is slightly larger than that in symmetric quark matter.

关键词： quark-gluon plasma equation of state speed of sound

Enhancement of photoacoustic tomography in the tissue with speed-of-sound variance using ultrasound computed tomography

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Chinese Physics B 2015年第11期24卷 63-69页

作者：程任翔陶超刘晓峻 Key Laboratory of Modern Acoustics of Ministry of Education Department of Physics Nanjing University

The speed-of-sound variance will decrease the imaging quality of photoacoustic tomography in acoustically inhomo- geneous tissue. In this study, ultrasound computed tomography is combined with photoacoustic tomography to enhance the photoacoustic tomography in this situation. The speed-of-sound information is recovered by ultrasound computed to- mography. Then, an improved delay-and-sum method is used to reconstruct the image from the photoacoustic signals. The simulation results validate that the proposed method can obtain a better photoacoustic tomography than the conventional method when the speed-of-sound variance is increased. In addition, the influences of the speed-of-sound variance and the fan-angle on the image quality are quantitatively explored to optimize the image scheme. The proposed method has a good performance even when the speed-of-sound variance reaches 14.2%. Furthermore, an optimized fan angle is revealed, which can keep the good image quality with a low cost of hardware. This study has a potential value in extending the biomedical application of photoacoustic tomography.

关键词： photoacoustic tomography speed of sound ultrasound computed tomography

A Method of Measuring the In Situ Seafloor sound speed using Two Receivers with WarDing Transformation

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Chinese Physics Letters 2014年第2期31卷 74-77页

作者：李风华张波郭永刚 State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190 University of Chinese Academy of Sciences Beijing 100190

We present a method of measuring the in situ superficial seafloor sound speed by using two receivers deployed vertically in sediment, based on the dispersion characteristic of normal modes in shallow water. Warping transfor- mation is adopted to extract the first normal mode from the broadband propagation signals. Some experimental results which could validate the method are shown. One of the advantages of the method is that the seafloor sound speed can be solved directly from the relative vertical transmission loss of the first normal mode without the exact priori information of the environmental parameters such as the sound speed profile, the water-column depth and the source location.

关键词： speed of sound UNDERWATER acoustics -- Measurement OCEAN bottom THEORY of wave motion ACOUSTIC receivers SIGNAL processing

Inversion for sound speed Profile by Using a Bottom Mounted Horizontal Line Array in Shallow Water

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Chinese Physics Letters 2010年第8期27卷 106-109页

作者：李风华张仁和 State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190

Ocean acoustic tomography is an appealing technique for remote monitoring of the ocean environment. In shallow water, matched field processing （MFP） with a vertical line array is one of the widely used methods for inverting the sound speed profile （SSP） of water column. The approach adopted is to invert the SSP with a bottom mounted horizontal line array （HLA） based on MFP. Empirical orthonormal functions are used to express the SSP, and perturbation theory is used in the forward sound field calculation. This inversion method is applied to the data measured in a shallow water acoustic experiment performed in 2003, Successful results show that the bottom mounted HLA is able to estimate the SSP. One of the most important advantages of the inversion method with bottom mounted HLA is that the bottom mounted HLA can keep a stable array shape and is safe in a relatively long period.

关键词： OCEAN tomography speed of sound REMOTE sensing SIGNAL processing EMPIRICAL research INVERSION (Geophysics)

sound waves in fluidized bed using CFD-DEM simulations

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Particuology 2018年第3期16卷 126-133页

作者： Hassan Abbas Khawaja Process and Gas Group Department of Engineering & Safety UiT-The Arctic University of Norway 9037 Langnes Tromso Norway

The speed of sound waves in a fluidized bed is investigated using CFD-DEM numerical simulations, Appro- priate initial and boundary conditions are applied to reproduce bed phenomena. The effect of varying the height of the bed is also studied. The results of the simulations matched those from the literature. The pressure and particle velocity profiles obtained feature oscillatory behavior to which functions （based on a damped standing wave） were fitted, enabling an explicit dependence on time and space variables to be established. These fitted functions were substituted into the linearized governing equations for the two-phase flow. These solutions enabled a new relationship to be derived for the speed of sound and damping in the system. The conclusion drawn is tbat the damping in the system is governed by the effective bulk viscosity of the solid phase, which arises from the particle viscosity.

关键词： Fluidized bed sound waves speed of sound Damping time CFD-DEM simulations

Properties of the phase diagram from the Nambu-Jona-Lasino model with a scalar-vector interaction

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Nuclear Science and Techniques 2024年第10期35卷 168-179页

作者： Yong-Hang Yang He Liu Peng-Cheng Chu Science School Qingdao University of TechnologyQingdao 266520China The Research Center of Theoretical Physics Qingdao University of TechnologyQingdao 266033China

We investigated the properties of the phase diagram of high-order susceptibilities,speed of sound,and polytropic index based on an extended Nambu-Jona-Lasinio model with an eight-quark scalar-vector ***-monotonic behavior was observed in all these quantities around the phase transition boundary,which also revealed the properties of the critical ***,this study indicated that the chiral phase transition boundary and critical point could vary depending on the scalarvector coupling constant G_(SV).At finite densities and temperatures,the negative G_(SV)term exhibited attractive interactions,which enhanced the critical point temperature and reduced the chemical *** G_(SV)term also affected the properties of the high-order susceptibilities,speed of sound,and polytropic index near the critical *** non-monotonic(peak or dip)structures of these quantities shifted to a low baryon chemical potential(and high temperature)with a negative G_(SV).G_(SV)also changed the amplitude and range of the nonmonotonic ***,the scalar-vector interaction was useful for locating the phase boundary and critical point in QCD phase diagram by comparing the experimental *** study of the non-monotonic behavior of high-order susceptibilities,speed of sound,and polytropic index is of great interest,and further observations related to high-order susceptibilities,speed of sound,and polytropic index being found and applied to the search for critical points in heavy-ion collisions and the study of compact stars are eagerly awaited.

关键词： QCD phase diagram High-order susceptibilities speed of sound Polytropic index NJL model

Volumetric and ultrasonic properties of thiamine hydrochloride drug in aqueous solutions of choline-based deep eutectic solvents at different temperatures

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Chinese Journal of Chemical Engineering 2023年第10期62卷 21-30页

作者： Hemayat Shekaari Fariba Ghaffari Masumeh Mokhtarpour Department of Physical Chemistry University of TabrizTabrizIran

Important efforts have been made over the past years to improve the drug acts,which leads to the discovery of novel drug preparations and delivery *** optimal design of such processes requires a molecular-level understanding of the interactions between drug molecules and biological *** thermodynamic investigation provides deep and complete knowledge of interactions and the choice of appropriate and suitable production compounds in pharmaceutical ***,the analysis of drugs+co-solvents in aqueous media is the central issue in many types of research because they exert their impact by interacting with biological *** work is aimed to measure the density and speed of sound for the thiamine hydrochloride in water+deep eutectic solvents(DESs)mixtures(choline chloride/urea,choline chloride/ethylene glycol and choline chloride/glycerol)at temperature range(293.15-308.15)*** correlation of the evaluated parameters in some standard relations,the partial molar parameters *** molar volumes,Vφ,m,and apparent molar isentropic compression,κ_(s,φ,m),are *** addition,apparent molar isobaric expansion,E^(0)_(φ,m),and Hepler’s constant are computed from the density and speed of sound *** fitting the experimental Vφ,m andκ_(s,φ,m)the Redlich-Meyer equation was employed that the important quantities;standard partial molar volume,V^(0)_(m),and partial molar isentropic compression,κφ,m0,were *** thermodynamic analysis of the studied system also plays a crucial role in the pharmaceutical industry.

关键词： Deep eutectic solvents Thiamine hydrochloride Density speed of sound Redlich-Meyer equation

Temperature-dependent aggregation of bio-surfactants in aqueous solutions of galactose and lactose:Volumetric and viscometric approach

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1119-1131页

作者： S.Chauhan Vivek Sharma Maninder Kaur Poonam Chaudhary Department of chemistry Himachal Pradesh University

Modulation in the aggregation behavior of bio-surfactants （bile salts）, sodium cholate （NaC） and sodium deoxycholate （NaDC） in aqueous solutions of carbohydrates （galactose and lactose） have been investigated by measuring the density （ρ）, speed of sound （u） and viscosity （η） of the mixtures at different temperatures 293.15, 298.15, 303.15, 308.15 and 313.15 K. The density and speed of sound data have been used to calculate various volumetric and compressibility parameters such as apparent molar volume （Vφ）, isentropic compressibil- ity （κs）, apparent molar adiabatic compression （κs,φ） to get a better insight into the micellization mechanism of bile salts. Further, the viscosity data have been studied in the light of relative viscosity （ηr） and viscous relaxation time （τ）. Some derived parameters such as free volume （νf）, internal pressure （πi） and molar cohesive energy （MCE） of NaC and NaDC in aqueous solution of saccharides have also been calculated from viscosity data in con- junction with density and speed of sound values. All the calculated and derived parameters provide qualitative information regarding the nature of interactions i.e. solute-solute, solute-solvent and solvent-solvent in the solution.

关键词： Density speed of sound Apparent molar volumelsentropic compressibility Viscosity Relative viscosity

CAVITATION CONTROL BY AERATION AND ITS COMPRESSIBLE CHARACTERISTICS

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Journal of Hydrodynamics 2006年第4期18卷 499-504页

作者： DONG Zhi-yong SU Pei-lan School of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310032 China School of Forestry Shanxi Agricultural University Taigu 030801 China

This paper presents an experimental investigation and a theoretical analysis of cavitation control by aeration and its compressible characteristics at the flow velocity V=20m/s-50m/s. Pressure waveforms with and without aeration in cavitation region were measured. The variation of compression ratio with air concentration was described, and the relation between the least air concentration to prevent cavitation erosion and flow velocity proposed based on our experimental study. The experimental results show that aeration remarkably increases the pressure in cavitation region, and the corresponding pressure wave exhibits a compression wave/shock wave. The pressure increase in cavitation region of high-velocity flow with aeration is due to the fact that the compression waves/shock wave after the flow is aerated. The compression ratio increases with air concentration rising. The relation between flow velocity and least air concentration to prevent cavitation erosion follows a semi-cubical parabola. Also, the speed of sound and Mach number of high-velocity aerated flow were analyzed.

关键词： cavitation control by aeration compression wave/shock wave least air concentration speed of sound compression ratio