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Alloy gene Gibbs energy partition function and equilibrium holographic network phase diagrams of AuCu_3-type sublattice system 被引量:3
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作者 谢佑卿 李小波 +2 位作者 刘心笔 聂耀庄 彭红建 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3585-3610,共26页
Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing exp... Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing experimental phenomena of alloy phase transitions during extremely slow variation in temperature by equilibrium thinking mode and then taking erroneous knowledge of experimental phenomena as selected information for establishing Gibbs energy function and so-called equilibrium phase diagram. Second, the equilibrium holographic network phase diagrams of AuCu3-type sublattice system may be used to describe systematic correlativity of the composition?temperature-dependent alloy gene arranging structures and complete thermodynamic properties, and to be a standard for studying experimental subequilibrium order-disorder transition. Third, the equilibrium transition of each alloy is a homogeneous single-phase rather than a heterogeneous two-phase, and there exists a single-phase boundary curve without two-phase region of the ordered and disordered phases; the composition and temperature of the top point on the phase-boundary curve are far away from the ones of the critical point of the AuCu3 compound. 展开更多
关键词 AuCu3 compound AuCu3-type sublattice system alloy gene Gibbs energy partition function equilibrium holographic network phase diagram systematic metal materials science
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Alloy gene Gibbs energy partition function and equilibrium holographic network phase diagrams of Au_3Cu-type sublattice system 被引量:3
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作者 谢佑卿 聂耀庄 +2 位作者 李小波 彭红建 刘心笔 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第1期211-240,共30页
Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that... Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that the Gibbs energy function of an alloy phase should be derived from Gibbs energy partition function constructed of alloy gene sequence and their Gibbs energy sequence. Second, the six rules for establishing alloy gene Gibbs energy partition function have been discovered, and it has been specially proved that the probabilities of structure units occupied at the Gibbs energy levels in the degeneracy factor for calculating configuration entropy should be degenerated as ones of component atoms occupied at the lattice points. Third, the main characteristics unexpected by today’s researchers are as follows. There exists a single-phase boundary curve without two-phase region coexisting by the ordered and disordered phases. The composition and temperature of the top point on the phase-boundary curve are far away from those of the critical point of the Au3Cu compound; At 0 K, the composition of the lowest point on the composition-dependent Gibbs energy curve is notably deviated from that of the Au3Cu compounds. The theoretical limit composition range of long range ordered Au3Cu-type alloys is determined by the first jumping order degree. 展开更多
关键词 Au3Cu compound Au3Cu-type sublattice system alloy gene Gibbs energy partition function equilibrium holographic network phase diagrams systematic metal materials science
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Partition Functions for Diatomic Molecules in Plasmas out of Thermal Equilibrium 被引量:1
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作者 Graldine FAURE 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第3期192-200,共9页
Two calculation methods on the partition functions for diatomic molecules in plas- mas out of thermal equilibrium are reported. A Boltzmann distribution for the electronic, vi- brational and rotational quantum levels ... Two calculation methods on the partition functions for diatomic molecules in plas- mas out of thermal equilibrium are reported. A Boltzmann distribution for the electronic, vi- brational and rotational quantum levels is assumed in the two calculation methods. The results obtained by two methods are displayed for four sorts of diatomic molecules, 02, N2, OH and NO, that are present in humid air plasmas. The calculation method of density for the electronically excited states is developed. Finally, a method to calculate the partition functions for simulating the non-normalized diatomic spectra is discussed. 展开更多
关键词 partition function Boltzmann distribution diatomic molecule
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Pseudo-Classical Partition Function of Spin One-Half Derived by Coherent State Method
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作者 许业军 范洪义 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1046-1048,共3页
Using the bosonic coherent state representation and the Schwinger bosonic operator realization of angular momentum we find the formula for the quantum Hamiltonian H =iaiUijUjl a1 for SU(2) rotation U, in this way w... Using the bosonic coherent state representation and the Schwinger bosonic operator realization of angular momentum we find the formula for the quantum Hamiltonian H =iaiUijUjl a1 for SU(2) rotation U, in this way we further specify the angular velocity w, iUU = (1/2)σ·ω, where σ is the Pauli matrix. Though the spin as a quantum observable has no classical correspondence, we may still mimic it as a rigid body rotation characterized by 3 Euler angles, and calculate its Pseudo-classical rotational partition function of spin one-half. 展开更多
关键词 partition function coherent state angular velocity the IWOP technique
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Rapidly calculating the partition function of macroscopic systems
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作者 李菁田 宁博元 +2 位作者 龚乐诚 庄军 宁西京 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期236-241,共6页
It has remained an open problem to accurately compute the partition function of macroscopic systems since the establishment of statistical physics. A rapid method approaching this problem was presented and was strictl... It has remained an open problem to accurately compute the partition function of macroscopic systems since the establishment of statistical physics. A rapid method approaching this problem was presented and was strictly tested by molecular dynamic (MD) simulations on Ar atoms in both dense gaseous and liquid states. The outcomes from the method on the internal energy and the work of isothermal expansion (and therefore the free energy) are in good agreement with the MD simulations, suggesting the method would be immediately applied in vast areas. 展开更多
关键词 partition function statistical physics free energy calculation
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Calculation of Partition Function of QCD at Finite Chemical Potential
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作者 SUN Wei-Min ZONG Hong-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第2期435-438,共4页
In equilibrium statistical field theory, the partition function has fundamental importance. In this paper we propose a direct and general method for calculating the partition function and equation of state of QCD at f... In equilibrium statistical field theory, the partition function has fundamental importance. In this paper we propose a direct and general method for calculating the partition function and equation of state of QCD at finite chemical potential. It is found that the partition function is totally determined by the dressed quark propagator at finite chemical potential up to a multiplicative constant. From this a criterion for the phase transition between the Nambu and the Wigner phases is obtained. This general method is applied to two specific cases: the free quark theory and QCD with a model dressed quark propagator having confinement features. In the first case, the standard Fermi distribution at T = 0 is reproduced. In the second case, we apply the conclusion in previous works to obtain the dressed quark propagator at finite chemical potential and find the unphysical result that the baryon number density vanishes for all values of chemical potential. The reason for this result is discussed. 展开更多
关键词 partition function of QCD phase transition
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Using “Particle Density” of “Graviton Gas”, to Obtain Value of Cosmological Constant
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作者 Andrew Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期168-173,共6页
We use the work of de Vega, Sanchez, and Comes (1997), to approximate the “particle density” of a “graviton gas”. This “particle density” derivation is compared with Dolgov’s (1997) expression of the Vacuum ene... We use the work of de Vega, Sanchez, and Comes (1997), to approximate the “particle density” of a “graviton gas”. This “particle density” derivation is compared with Dolgov’s (1997) expression of the Vacuum energy in terms of a phase transition. The idea is to have a quartic potential, and then to utilize the Bogomol’nyi inequality to refine what the phase transition states. We utilize Ng, Infinite quantum information procedures to link our work with initial entropy and other issues and close with a variation in the HUP: at the start of the expansion of the universe. 展开更多
关键词 Graviton Gas partition Function Modified HUP Symmetry Breaking Potential
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High Temperature Spectrum for v3 Band of Carbon Dioxide 被引量:6
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作者 SONG Xiao-Shu YANG Xiang-Dong +3 位作者 GUO Yun-Dong WANG Jun CHENG Xin-Lu LING-HURong-Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5期892-896,共5页
The total internal partition sums (TIPS) are calculated at the temperature up to 6000 K for 12 C16 02. Using the calculated partition functions, we produce the line intensities of v3 band of 12C1602 at several high ... The total internal partition sums (TIPS) are calculated at the temperature up to 6000 K for 12 C16 02. Using the calculated partition functions, we produce the line intensities of v3 band of 12C1602 at several high temperatures. The results show that the calculated line intensities are in very good agreement with those of HITRAN database at the temperature up to 3000 K, which provides a strong support for the calculations of TIPS and line intensities at high temperature. Then the calculation is extended to further high temperature, and the simulated spectra of u3 band of 12C1602 at 5000 and 6000 K are reported. 展开更多
关键词 partition functions carbon dioxide line intensities high temperature
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Line intensities of the asymptotic asymmetric-top radical HO_2 at high temperatures 被引量:3
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作者 宋晓书 程新路 +2 位作者 杨向东 令狐荣锋 吕兵 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期158-163,共6页
The total internal partition sums were calculated in the product approximation at temperatures up to 5000 K for the asymptotic asymmetric-top HO2 molecule. The calculations of the rotational partition function and the... The total internal partition sums were calculated in the product approximation at temperatures up to 5000 K for the asymptotic asymmetric-top HO2 molecule. The calculations of the rotational partition function and the vibrational partition function were carried out with the rigid-top model and in the harmonic oscillator approximation, respectively. Our values of the total internal partition sums are consistent with the data of HITRAN database with -0.14% at 296 K. Using the calculated partition functions, we have calculated the line intensities of υ2 band of HO2 at several high temperatures. The results showed that the calculated line intensities are in very good agreement with those of HITRAN database at temperatures up to 3000 K, which provides a strong support for the calculations of partition functions and line intensities at high temperatures. Then we have extended the calculation to higher temperatures. The simulated spectra of υ2 band of the asymptotic asymmetric-top HO2 molecule at 4000 and 5000 K are also obtained. 展开更多
关键词 asymptotic asymmetric-top molecule line intensities partition functions high temperature
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Study on High-Temperature Spectra of Asymptotic Asymmetric-Top Molecule O_3 被引量:1
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作者 SONG Xiao-Shu GUO Yun-Dong +3 位作者 LING-HU Rong-Feng Lv Bing CHENG Xin-Lu YANG Xiang-Dong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第8期481-485,共5页
The line intensities of 001-000 transition of the asymptotic asymmetric-top Oa molecule at several temperatures are calculated by directly calculating the partition functions and regarding the rotationless transition ... The line intensities of 001-000 transition of the asymptotic asymmetric-top Oa molecule at several temperatures are calculated by directly calculating the partition functions and regarding the rotationless transition dipole moment squared as a constant. The calculated values of the total internM partition sums (TIPS) are consistent with the data of HITRAN database with -0.61% at 296 K. The calculated line intensity data at 500 K and 3000 K are also in excellent agreement with the data in HITRAN database with less than 0.659% and 5.458% at 500 K and 3000 K, which provide a strong support for the calculations of partition function and fine intensity at high temperature. Then we extend the calculation to higher temperatures. The line intensities and simulated spectra of v3 band of the asymptotic asymmetric-top O3 molecule at 4000 and 5000 K are reported. The results are of significance for the studying of the molecular high-temperature spectrum including experimental measurements and theoretical calculations. 展开更多
关键词 asymptotic asymmetric-top molecule line intensities partition functions high temperature spectrum
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Study on high-temperature spectra of asymptotic asymmetric-top radical SiO_2 被引量:1
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作者 伍冬兰 曾学锋 +1 位作者 谢安东 万慧军 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第4期208-212,共5页
Total internal partition sums are calculated in the product approximation at temperatures up to 6000K for the asymptotic asymmetric-top SiO2 molecule. The rotational partition function and the vibrational partition fu... Total internal partition sums are calculated in the product approximation at temperatures up to 6000K for the asymptotic asymmetric-top SiO2 molecule. The rotational partition function and the vibrational partition function are calculated with the rigid-top model and in the harmonic oscillator approximation, respectively. Our values of the total internal partition sums are consistent with the calculated value in the Gaussian program within $-0.137$% at 296K. Using the calculated partition functions and the rotationless transition dipole moment squared as a constant, we calculate the line intensities of 001--000 band of SiO2 at normal, medium and high temperatures. Simulated spectra of the 001--000 band of the asymptotic asymmetric-top SiO2 molecule at 2000, 5000 and 6000K are also obtained. 展开更多
关键词 asymptotic asymmetric-top molecule line intensities partition functions high temperature spectra
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Forced motion of an elastic filament through a narrow tube 被引量:1
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作者 L.B.Freund 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第6期789-790,共2页
A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined ... A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined in a thermal environment, such a flexible strand may become tangled owing to its flexibility. When confined within a narrow "tube" over its full length, a flexible molecule may behave quite differently. Here, we consider the qualitative nature of deformation of an individual filament when confined within a tube. Commonly the tube is formed within the cluster by a large number of surrounding filaments of the same type. 展开更多
关键词 Statistical mechanics. Biofilament. Reptation partition function
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The second-order dynamic phase transition and Lee-Yang zeros in Eggers urn model
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作者 刘小贤 童培庆 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第11期3930-3935,共6页
A second-order dynamic phase transition in a non-equilibrium Eggers urn model for the separation of sand is studied. The order parameter, the susceptibility and the stationary probability distribution have been calcul... A second-order dynamic phase transition in a non-equilibrium Eggers urn model for the separation of sand is studied. The order parameter, the susceptibility and the stationary probability distribution have been calculated. By applying the Lee-Yang zeros method of equilibrium phase transitions, we study the distributions of the effective partition function zeros and obtain the same result for the model. Thus, the Lee-Yang theory can be applied to a more general non-equilibrium system. 展开更多
关键词 urn model non-equilibrium system Lee-Yang theory partition function
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Generalized Fourth-Order Decompositions of Imaginary Time Path Integral:Implications of the Harmonic Oscillator
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作者 Cong Wang Lihan Zhang +1 位作者 Jian Liu Jiushu Shao 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第3期516-536,I0003,共22页
The imaginary time path integral formalism offers a powerful numerical tool for simulating thermodynamic properties of realistic systems.We show that,when second-order and fourth-order decompositions are employed,they... The imaginary time path integral formalism offers a powerful numerical tool for simulating thermodynamic properties of realistic systems.We show that,when second-order and fourth-order decompositions are employed,they share a remarkable unified analytic form for the partition function of the harmonic oscillator.We are then able to obtain the expression of the thermodynamic property and the leading error terms as well.In order to obtain reasonably optimal values of the free parameters in the generalized symmetric fourth-order decomposition scheme,we eliminate the leading error terms to achieve the accuracy of desired order for the thermodynamic property of the harmonic system.Such a strategy leads to an efficient fourth-order decomposition that produces thirdorder accurate thermodynamic properties for general systems. 展开更多
关键词 Path integral DECOMPOSITION partition function Harmonic oscillator
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Correct Path-Integral Formulation of Quantum Thermal Field Theory in Coherent State Representation
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作者 SUJun-Chen ZHENGFu-Hou 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期641-656,共16页
The path-integral quantization of thermal scalar, vector, and spinor fields is performed newly in the coherent-state representation. In doing this, we choose the thermal electrodynamics and psi(4) theory as,examples. ... The path-integral quantization of thermal scalar, vector, and spinor fields is performed newly in the coherent-state representation. In doing this, we choose the thermal electrodynamics and psi(4) theory as,examples. By this quantization, correct expressions of the partition functions and the generating functionals for the quantum thermal electrodynamics and psi(4) theory are obtained in the coherent-state representation. These expressions allow us to perform analytical calculations of the partition functions and generating functionals and therefore are useful in practical applications. Especially, the perturbative expansions of the generating functionals are derived specifically by virtue of the stationary-phase method. The generating functionals formulated in the position space are re-derived from the ones given in the coherent-state representation. 展开更多
关键词 thermal fields partition function generating functional coherent-state representation
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Boundary Correlation Functions of the gl(1|1) Supersymmetric Vertex Model
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作者 ZHANG Chen-Jun ZHOU Jian-Hua YUE Rui-Hong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第7期17-22,共6页
The gl(1/1) supersymmetric vertex model with domain wall boundary conditions (DWBC) on an N × N square lattice is considered. We derive the reduction formulae for the one-point boundary correlation functions ... The gl(1/1) supersymmetric vertex model with domain wall boundary conditions (DWBC) on an N × N square lattice is considered. We derive the reduction formulae for the one-point boundary correlation functions of the model. The determinant representation for the boundary correlation functions is also obtained. 展开更多
关键词 domain wall boundary conditions partition function boundary correlation function
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Coherent state evolution in a Raman dispersion process
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作者 杜建明 任刚 范洪义 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第9期1-4,共4页
1. Introduction In quantum optics, optical frequency conversion is a typical nonlinear process and is worth studying, for example, a second harmonic frequency generation will generate a squeezed state.[1'2l In this ... 1. Introduction In quantum optics, optical frequency conversion is a typical nonlinear process and is worth studying, for example, a second harmonic frequency generation will generate a squeezed state.[1'2l In this work, we tackle the evolution of an initial coherent state in a Raman dispersion process which is also a nonlinear process. The process involves the inelastic scattering of a pho- ton when it is incident on a molecule. The photon loses some of its energy to the molecule or gains some from it, and so leaves the molecule with a lower or a higher frequency. The lower frequency components of the scattered radiation are called the Stokes lines and the higher frequency components are called the anti- Stokes lines. The Hamiltonian governing its dynamics is[3] 展开更多
关键词 Raman dispersion process integration within an ordered products of operators three-mode coherent state partition function
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分子阻障内旋转配分函数的二点pade’逼近
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作者 潘慧云 《郑州大学学报(理学版)》 CAS 1987年第2期90-93,共4页
一、分子阻障内旋转配分函数的计算在理论化学中一直为人们所研究,早在五十年代Pitzer就用数值方法进行了计算,但求得这一配分函数的近似解析表示式仍有重要意义,在文献中作者曾用Wigner-Kirkwood微扰展开法求得阻障内旋转配分函数的近... 一、分子阻障内旋转配分函数的计算在理论化学中一直为人们所研究,早在五十年代Pitzer就用数值方法进行了计算,但求得这一配分函数的近似解析表示式仍有重要意义,在文献中作者曾用Wigner-Kirkwood微扰展开法求得阻障内旋转配分函数的近似解析表示式,根据此式所作的数值计算结果表明:在温度较高,内旋转动惯量较大时和Pitzer的数值计算结果符合得甚好,但随着温度的降低偏离也就增大,计算Wigner-Kirkwood展开式的的高次项固然可以改善所得之配分函数,但此时计算烦杂,困难较大,本文则采用二点Pade’逼近法将Wigner-Kirkwood微扰展开式(包括一级量子改正项)作为高温展开式,并选用配分函数Q=Σe-tEi的前三项作为其低温展开式,然后用二点Pade’逼近进行内插,求得阻障内旋转配分函数的[5/5]Pade’逼近式,它在整个温度范围内均能给出良好的数值结果。 展开更多
关键词 Pade’ approximant partition function internal rotation.
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Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators
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作者 XU Xiu-Wei REN Ting-Qi LIU Shu-Yan MA Qiu-Ming LIU Sheng-Dian 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第1期41-44,共4页
Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary m... Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary matrix elements for BEQPO's. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO's. 展开更多
关键词 Boson exponential quadratic polynomial operator matrix element P representation partition function of Boson quadratic polynomial system
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A HIGH SPEED ADAPTIVE FRACTAL IMAGE CODING ALGORITHM USING FLEXIBLE CLASSIFICATION TECHNIQUE
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作者 Zhang Liang Li Weihua Wang Qiao 《Wuhan University Journal of Natural Sciences》 CAS 1998年第2期146-146,共1页
Traditionally, fractal image compression suffers from lengthy encoding time in measure ofhours. In this paper, combined with characteristlcs of human visual system, a flexible classification technique is proposed. Thi... Traditionally, fractal image compression suffers from lengthy encoding time in measure ofhours. In this paper, combined with characteristlcs of human visual system, a flexible classification technique is proposed. This yields a corresponding adaptive algorithm which can cut down the encoding timeinto second's magnitude. Experiment results suggest that the algorithm can balance the overall encodingperformance efficiently, that is, with a higher speed and a better PSNR gain. 展开更多
关键词 image coding fractal image coding iterated function system (IFS) partitioned iterated function system (PIFS) characteristics of human visual system
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