From the Gibbs free energy and the equations of two-phase equilibrium curves of the two-dimensionalbinary system which has the Lennard-Jones potential, using the Collins model, the eutectic-type phase diagram and thep...From the Gibbs free energy and the equations of two-phase equilibrium curves of the two-dimensionalbinary system which has the Lennard-Jones potential, using the Collins model, the eutectic-type phase diagram and theperitectic-type phase diagram of the binary system are obtained, whose results are quite similar to the behavior of thethree-dimensional (3D) substances.展开更多
The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal field is studied within themean-field theory.The phase diagrams and magnetization curves are obtained by diagonalizing the Hamiltonian H_i of...The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal field is studied within themean-field theory.The phase diagrams and magnetization curves are obtained by diagonalizing the Hamiltonian H_i ofthe Ising system numerically,and the first order-order phase transitions,the first order-disorder phase transitions,andthe second-order phase transitions are discussed in details.Reentrant phenomena occur when the value of the transversefield is not zero and the reentrant diagram is given.展开更多
The Collins model is introduced into the two-dimensional (2D) alternative ternary system having the Lennard-Jones (L-J) potential. The Gibbs free energy of this ternary system is calculated, and according to thermodyn...The Collins model is introduced into the two-dimensional (2D) alternative ternary system having the Lennard-Jones (L-J) potential. The Gibbs free energy of this ternary system is calculated, and according to thermodynamic theory, a group of equations that determine the solid-liquid diagram of ternary system are derived, someisothermal sectional diagrams of the 2D ternary system are obtained. The results are quite similar to the behavior ofthree-dimensional substances.展开更多
<正> The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within themean-field theory based on Bogoliubov inequality for the Gibbs free energy.The ground-state phase diagr...<正> The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within themean-field theory based on Bogoliubov inequality for the Gibbs free energy.The ground-state phase diagram and thetricritical point are obtained in the transverse field Ω/zJ-longitudinal crystal D/zJ field plane.We find that there are thefirst order-order phase transitions in a very small range of D/zJ besides the usual first order-disorder phase transitionsand the second order-disorder phase transitions.展开更多
From the measured phase equilibria data and experimental thermochemical properties, the TmCl3-ACl (A=Na, K, Rb, Cs) phase diagrams were optimized and calculated using the CALPHAD technique. For describing the Gibbs ...From the measured phase equilibria data and experimental thermochemical properties, the TmCl3-ACl (A=Na, K, Rb, Cs) phase diagrams were optimized and calculated using the CALPHAD technique. For describing the Gibbs energies of the liquid phase in these systems, the new modified quasichemical model in the pair-approximation for short-range ordering was used. A set of thermodynamic functions was optimized and gotten based on an interactive computer-assisted analysis. The calculated phase diagrams and thermodynamic data are self-consistent.展开更多
YbCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated using the CALPHAD (CALculation of PHAse Diagram) technique. The modified quasi-chemical model in the pair-approximation for short-range ordering was ...YbCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated using the CALPHAD (CALculation of PHAse Diagram) technique. The modified quasi-chemical model in the pair-approximation for short-range ordering was used to describe the Gibbs energies of liquid phase in the systems. On the basis of the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized and calculated through an interactive computer-assisted analysis. Furthermore, some reasonable discussions on the thermodynamic parameters for these strong interaction binary systems were carried out. The results showed that the optimized parameters and experimental data are thermodynamically self-consistent.展开更多
The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonaliz...The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonalization calculations and an exactly solvable model. We find some basic features essentially different from the bilayer integer QH systems at ν = 2, reflecting the special characteristics of the fractional QH systems. The degeneracy of the ground states occurs depending on the difference between intralayer and interlayer Coulomb energies, when interlayer tunneling energy (ΔSAS) gets close to zero. The continuous transitions of the finite size systems between the spin-polarized and spin-unpolarized phases are determined by the competition between the Zeeman energy (ΔZ) and the electron Coulomb energy, and are almost not affected by ΔSAS.展开更多
The mathematical formulas are given for calculating the partial molar thermodynamic proper-ties in a ternary system from its three corresponding binary systems based on the new ternarysymmetric model presented by the ...The mathematical formulas are given for calculating the partial molar thermodynamic proper-ties in a ternary system from its three corresponding binary systems based on the new ternarysymmetric model presented by the authors in the foregoing paper.Applying this model toNaCl-BaCl<sub>2</sub>-SrCl<sub>2</sub> system,the phase diagram of which as well as some isothermal sectionshave been calculated.The devations of temperature between the calculated and experimen-tal diagrams are less than five degrees.展开更多
For a long period of time, the determination of phase diagrams was only supported by experiments related to thermal effects or thermodynamic measurements: thermal analysis, calorimetric measurements, vapor pressures, ...For a long period of time, the determination of phase diagrams was only supported by experiments related to thermal effects or thermodynamic measurements: thermal analysis, calorimetric measurements, vapor pressures, and EMF measurements. As a matter of fact, solid-solid transformations were not so accurately determined and could not be taken into account in the system’s analysis. First, X-ray diffraction methods were used as a support for the thermal analysis. Sec- ond, the implementation of novel tools in structural analysis (for example, the Rietveld method) has permitted to increase the knowledge of phase stability. Finally, modeling the phases using a Calphad method needed increasingly more structural results to determine and better understand the phase diagrams. On the other hand, the Calphad method has been widely de- veloped for metallic systems, for oxide systems, and in the past 10 years, for some semi-conductor systems, for example, gallium arsenide, cadmium telluride, and lead telluride systems. In such applications, it is very important to bring point de- fects in the modeling of the phases to map the defects as a function of the chemical composition. Owing to its complexity, this characteristic, the knowledge of which is crucial for the understanding and the control of potential physical applications, was ignored in the previous assessment of semi-conductor systems.展开更多
Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as ...Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as free flow and wide moving jam states in the systems having relatively small values of the bottleneck strength parameter. In addition to the two phases, locally congested phaseappears as the strength becomes prominent. Jam formation occurs with the similar mechanism to the boomerang effect as well as the pinch one in it. Wide scattering of the flow-density relation in fundamental diagram is found in the congested phase.展开更多
蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型...蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型,以揭示蚀变分带成因和金属成矿机制。LMA与GEM结果显示初始成矿流体pH值为4.7,log f O 2=-23.0(ΔFMQ=+2.7),且溶解Cu含量为1138×10^(-6),Mo为1.2×10^(-6)。研究表明,当该酸性及强氧化性流体流入二长花岗斑岩体时,在温度为450~360℃范围内,代表钾硅酸盐化蚀变的钾长石、黑云母、硬石膏、赤铁矿和磁铁矿的矿物逐渐沉淀,且与钾硅酸盐化蚀变相关流体具有较高pH值(5.0~7.0)和氧逸度(ΔFMQ=+2.9~+3.6)特征;当温度在360~320℃范围时,代表青磐岩化蚀变阶段的典型矿物如绿帘石、铁绿泥石和斜绿泥石等逐渐形成,流体pH值(5.0~6.4)和氧逸度(ΔFMQ=+1.1)均有所下降;当温度进一步从320℃下降到200℃时,流体pH值(5.0~5.7)进一步小幅下降,而氧逸度则(ΔFMQ=+1.7)略有回升,在此期间,绢云母和方解石等开始沉淀并形成典型的绢英岩化蚀变。此外,以HMoO-4和MoO 2-4为载体的Mo在狭窄高温区间(450~370℃)内沉淀,而以CuCl(CuCl 3-4、CuCl-2、CuCl)为主要载体的Cu则在在中、高温(450~300℃)范围中沉淀。通过利用LMA反演及GEM正演相结合定量化地刻画了玉龙斑岩铜矿水岩反应过程,由此揭示了斑岩矿床蚀变分带是逐渐冷却的单一岩浆热液与斑岩体不断反应的结果,且不同温度窗口对应着钾硅酸盐化(450~360℃)、青磐岩化(360~320℃)和绢英岩化(320~200℃)蚀变矿物的形成,故含矿流体温度的快速下降可能是玉龙铜矿蚀变叠加的重要因素。此外,Cu、Mo络合离子溶解度对温度变化的差异响应,导致了Mo矿化主要发育于靠近斑岩体的高温区域,而Cu则以网脉状-浸染状叠加到Mo矿化之上,并广泛分布于斑岩体周边的高-中温区域。展开更多
This pilot study was to assess the high temperature and zero baryon density region of quantum chromodynamics(QCD) phase diagram with thermal photon emission,where the nature of QCD phase transition is ambiguous.Based ...This pilot study was to assess the high temperature and zero baryon density region of quantum chromodynamics(QCD) phase diagram with thermal photon emission,where the nature of QCD phase transition is ambiguous.Based on a(3+1)-D ideal hydrodynamical model to describe macroscopically the collision system,thermal photons emitted from Pb+Pb collisions at 2.76 TeV are investigated.The result reveals that photons from heavy ion collisions at high energy and centrality are possible to distinguish the structure of the hot dense matter,in QGP phase or hadronic phase,thus may provide an approach to explore the nature of this finite-temperature QCD transition(that is,first-order,second-order or analytic crossover).展开更多
We study the finite-size scaling behavior of velocity and central charge for different coupling constantsand different phases in (1+1)-dimensional lattice model in very short chains. Using XXZ spin 1/2 chains with 15 ...We study the finite-size scaling behavior of velocity and central charge for different coupling constantsand different phases in (1+1)-dimensional lattice model in very short chains. Using XXZ spin 1/2 chains with 15 orfewcr sites, we demonstrate the weak finite-size dependence of spinon velocity for any magnitude of coupling strengthJz and the strong phase dependence of central charge. This behavior of velocity and central charge in different couplingconstants and different phases gives a method to determine phase transitions of (1+1)-dimensional mnodels. This methodis simple and cfficient by utilizing only the ground state energy of very short finite-size chains. It is also general andpowerful for various one-dimensional lattice models and it uncovers even the weakest Berezinsk Kosterlitz-Thoulessphase transitions.展开更多
A new model for predicting ternary thermodynamic properties from its three binary systems has been presented,that is<sup>E</sup>G<sub>m</sub>=((X<sub>1</sub>X<sub>2</sub&...A new model for predicting ternary thermodynamic properties from its three binary systems has been presented,that is<sup>E</sup>G<sub>m</sub>=((X<sub>1</sub>X<sub>2</sub>)/(V<sub>12</sub>V<sub>21</sub>)<sup>E</sup>G<sub>12</sub>(V<sub>12</sub>V<sub>21</sub>)+((X<sub>1</sub>X<sub>3</sub>)/(V<sub>13</sub>V<sub>31</sub>))<sup>E</sup>G<sub>13</sub>(V<sub>13</sub>,V<sub>31</sub>))+(1-X<sub>1</sub>)<sup>2</sup> <sup>E</sup>G<sub>23</sub>((X<sub>2</sub>/(1-X<sub>1</sub>)),(X<sub>3</sub>/1-X<sub>1</sub>))where <sup>E</sup>G<sub>m</sub> represents the ternary excess molar thermodynamic property; <sup>E</sup>G<sub>ij</sub>indicates the thermodynamic properties of i-jbinary systems; X<sub>i</sub> represents the mole fraction of component i of ternary solution,while V<sub>ii</sub>=(1+X<sub>i</sub>-X<sub>j</sub>)/2.The model is con-sidered to be rigorous in the case where the pseudobinary systems of fixed X<sub>2</sub>/X<sub>3</sub> are regular solution.The application of newmodel to the prediction of ternary enthalpies of mixing for Bi-Ga-Sn,Au-Ag-Sn and NaCI-KCI-CaCl<sub>2</sub> systems shows thatthe calculated results by new model are closer to experimental data than those by Toop’s model.展开更多
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XD02002400) and the National Natural Science Foundation of China(No.21473234).
文摘From the Gibbs free energy and the equations of two-phase equilibrium curves of the two-dimensionalbinary system which has the Lennard-Jones potential, using the Collins model, the eutectic-type phase diagram and theperitectic-type phase diagram of the binary system are obtained, whose results are quite similar to the behavior of thethree-dimensional (3D) substances.
基金Ph.D.Programs Foundation of Ministry of Education of China under Grant No.20040145019
文摘The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal field is studied within themean-field theory.The phase diagrams and magnetization curves are obtained by diagonalizing the Hamiltonian H_i ofthe Ising system numerically,and the first order-order phase transitions,the first order-disorder phase transitions,andthe second-order phase transitions are discussed in details.Reentrant phenomena occur when the value of the transversefield is not zero and the reentrant diagram is given.
基金The project supported by National Natural Science Foundation of China
文摘The Collins model is introduced into the two-dimensional (2D) alternative ternary system having the Lennard-Jones (L-J) potential. The Gibbs free energy of this ternary system is calculated, and according to thermodynamic theory, a group of equations that determine the solid-liquid diagram of ternary system are derived, someisothermal sectional diagrams of the 2D ternary system are obtained. The results are quite similar to the behavior ofthree-dimensional substances.
文摘<正> The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within themean-field theory based on Bogoliubov inequality for the Gibbs free energy.The ground-state phase diagram and thetricritical point are obtained in the transverse field Ω/zJ-longitudinal crystal D/zJ field plane.We find that there are thefirst order-order phase transitions in a very small range of D/zJ besides the usual first order-disorder phase transitionsand the second order-disorder phase transitions.
基金Project supported by the Foundation of Natural Science of Anhui Province (00046509) and Foundation of Natural Science of Anhui Education Committee (2000j1090)
文摘From the measured phase equilibria data and experimental thermochemical properties, the TmCl3-ACl (A=Na, K, Rb, Cs) phase diagrams were optimized and calculated using the CALPHAD technique. For describing the Gibbs energies of the liquid phase in these systems, the new modified quasichemical model in the pair-approximation for short-range ordering was used. A set of thermodynamic functions was optimized and gotten based on an interactive computer-assisted analysis. The calculated phase diagrams and thermodynamic data are self-consistent.
基金Key Project Foundation of Natural Science of Anhui Education Committee (KJ2008A083)
文摘YbCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated using the CALPHAD (CALculation of PHAse Diagram) technique. The modified quasi-chemical model in the pair-approximation for short-range ordering was used to describe the Gibbs energies of liquid phase in the systems. On the basis of the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized and calculated through an interactive computer-assisted analysis. Furthermore, some reasonable discussions on the thermodynamic parameters for these strong interaction binary systems were carried out. The results showed that the optimized parameters and experimental data are thermodynamically self-consistent.
文摘The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonalization calculations and an exactly solvable model. We find some basic features essentially different from the bilayer integer QH systems at ν = 2, reflecting the special characteristics of the fractional QH systems. The degeneracy of the ground states occurs depending on the difference between intralayer and interlayer Coulomb energies, when interlayer tunneling energy (ΔSAS) gets close to zero. The continuous transitions of the finite size systems between the spin-polarized and spin-unpolarized phases are determined by the competition between the Zeeman energy (ΔZ) and the electron Coulomb energy, and are almost not affected by ΔSAS.
文摘The mathematical formulas are given for calculating the partial molar thermodynamic proper-ties in a ternary system from its three corresponding binary systems based on the new ternarysymmetric model presented by the authors in the foregoing paper.Applying this model toNaCl-BaCl<sub>2</sub>-SrCl<sub>2</sub> system,the phase diagram of which as well as some isothermal sectionshave been calculated.The devations of temperature between the calculated and experimen-tal diagrams are less than five degrees.
文摘For a long period of time, the determination of phase diagrams was only supported by experiments related to thermal effects or thermodynamic measurements: thermal analysis, calorimetric measurements, vapor pressures, and EMF measurements. As a matter of fact, solid-solid transformations were not so accurately determined and could not be taken into account in the system’s analysis. First, X-ray diffraction methods were used as a support for the thermal analysis. Sec- ond, the implementation of novel tools in structural analysis (for example, the Rietveld method) has permitted to increase the knowledge of phase stability. Finally, modeling the phases using a Calphad method needed increasingly more structural results to determine and better understand the phase diagrams. On the other hand, the Calphad method has been widely de- veloped for metallic systems, for oxide systems, and in the past 10 years, for some semi-conductor systems, for example, gallium arsenide, cadmium telluride, and lead telluride systems. In such applications, it is very important to bring point de- fects in the modeling of the phases to map the defects as a function of the chemical composition. Owing to its complexity, this characteristic, the knowledge of which is crucial for the understanding and the control of potential physical applications, was ignored in the previous assessment of semi-conductor systems.
文摘Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as free flow and wide moving jam states in the systems having relatively small values of the bottleneck strength parameter. In addition to the two phases, locally congested phaseappears as the strength becomes prominent. Jam formation occurs with the similar mechanism to the boomerang effect as well as the pinch one in it. Wide scattering of the flow-density relation in fundamental diagram is found in the congested phase.
文摘蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型,以揭示蚀变分带成因和金属成矿机制。LMA与GEM结果显示初始成矿流体pH值为4.7,log f O 2=-23.0(ΔFMQ=+2.7),且溶解Cu含量为1138×10^(-6),Mo为1.2×10^(-6)。研究表明,当该酸性及强氧化性流体流入二长花岗斑岩体时,在温度为450~360℃范围内,代表钾硅酸盐化蚀变的钾长石、黑云母、硬石膏、赤铁矿和磁铁矿的矿物逐渐沉淀,且与钾硅酸盐化蚀变相关流体具有较高pH值(5.0~7.0)和氧逸度(ΔFMQ=+2.9~+3.6)特征;当温度在360~320℃范围时,代表青磐岩化蚀变阶段的典型矿物如绿帘石、铁绿泥石和斜绿泥石等逐渐形成,流体pH值(5.0~6.4)和氧逸度(ΔFMQ=+1.1)均有所下降;当温度进一步从320℃下降到200℃时,流体pH值(5.0~5.7)进一步小幅下降,而氧逸度则(ΔFMQ=+1.7)略有回升,在此期间,绢云母和方解石等开始沉淀并形成典型的绢英岩化蚀变。此外,以HMoO-4和MoO 2-4为载体的Mo在狭窄高温区间(450~370℃)内沉淀,而以CuCl(CuCl 3-4、CuCl-2、CuCl)为主要载体的Cu则在在中、高温(450~300℃)范围中沉淀。通过利用LMA反演及GEM正演相结合定量化地刻画了玉龙斑岩铜矿水岩反应过程,由此揭示了斑岩矿床蚀变分带是逐渐冷却的单一岩浆热液与斑岩体不断反应的结果,且不同温度窗口对应着钾硅酸盐化(450~360℃)、青磐岩化(360~320℃)和绢英岩化(320~200℃)蚀变矿物的形成,故含矿流体温度的快速下降可能是玉龙铜矿蚀变叠加的重要因素。此外,Cu、Mo络合离子溶解度对温度变化的差异响应,导致了Mo矿化主要发育于靠近斑岩体的高温区域,而Cu则以网脉状-浸染状叠加到Mo矿化之上,并广泛分布于斑岩体周边的高-中温区域。
基金Supported by National Natural Science Foundation of China(NSFC) projects (No.11275081)Program for New Century Excellent Talents in University(NCET)
文摘This pilot study was to assess the high temperature and zero baryon density region of quantum chromodynamics(QCD) phase diagram with thermal photon emission,where the nature of QCD phase transition is ambiguous.Based on a(3+1)-D ideal hydrodynamical model to describe macroscopically the collision system,thermal photons emitted from Pb+Pb collisions at 2.76 TeV are investigated.The result reveals that photons from heavy ion collisions at high energy and centrality are possible to distinguish the structure of the hot dense matter,in QGP phase or hadronic phase,thus may provide an approach to explore the nature of this finite-temperature QCD transition(that is,first-order,second-order or analytic crossover).
文摘We study the finite-size scaling behavior of velocity and central charge for different coupling constantsand different phases in (1+1)-dimensional lattice model in very short chains. Using XXZ spin 1/2 chains with 15 orfewcr sites, we demonstrate the weak finite-size dependence of spinon velocity for any magnitude of coupling strengthJz and the strong phase dependence of central charge. This behavior of velocity and central charge in different couplingconstants and different phases gives a method to determine phase transitions of (1+1)-dimensional mnodels. This methodis simple and cfficient by utilizing only the ground state energy of very short finite-size chains. It is also general andpowerful for various one-dimensional lattice models and it uncovers even the weakest Berezinsk Kosterlitz-Thoulessphase transitions.
基金Supported by National Natural Science Foundation of China under Grant No.10675108Foundation of Yancheng Institute of Technology under Grant No.XKR2010007
文摘A new model for predicting ternary thermodynamic properties from its three binary systems has been presented,that is<sup>E</sup>G<sub>m</sub>=((X<sub>1</sub>X<sub>2</sub>)/(V<sub>12</sub>V<sub>21</sub>)<sup>E</sup>G<sub>12</sub>(V<sub>12</sub>V<sub>21</sub>)+((X<sub>1</sub>X<sub>3</sub>)/(V<sub>13</sub>V<sub>31</sub>))<sup>E</sup>G<sub>13</sub>(V<sub>13</sub>,V<sub>31</sub>))+(1-X<sub>1</sub>)<sup>2</sup> <sup>E</sup>G<sub>23</sub>((X<sub>2</sub>/(1-X<sub>1</sub>)),(X<sub>3</sub>/1-X<sub>1</sub>))where <sup>E</sup>G<sub>m</sub> represents the ternary excess molar thermodynamic property; <sup>E</sup>G<sub>ij</sub>indicates the thermodynamic properties of i-jbinary systems; X<sub>i</sub> represents the mole fraction of component i of ternary solution,while V<sub>ii</sub>=(1+X<sub>i</sub>-X<sub>j</sub>)/2.The model is con-sidered to be rigorous in the case where the pseudobinary systems of fixed X<sub>2</sub>/X<sub>3</sub> are regular solution.The application of newmodel to the prediction of ternary enthalpies of mixing for Bi-Ga-Sn,Au-Ag-Sn and NaCI-KCI-CaCl<sub>2</sub> systems shows thatthe calculated results by new model are closer to experimental data than those by Toop’s model.