Does non-transitivity in information theory have an analog in thermodynamics? A non-transitive game, “Swap”, is used as a toy thermodynamic model to explore concepts such as temperature, heat flow, equilibrium and e...Does non-transitivity in information theory have an analog in thermodynamics? A non-transitive game, “Swap”, is used as a toy thermodynamic model to explore concepts such as temperature, heat flow, equilibrium and entropy. These concepts, found to be inadequate for non-transitive thermodynamic, need to be generalized. Two kinds of temperatures, statistical and kinetic, are distinguished. Statistical temperature is a parameter in statistical distributions. Kinetic temperature is proportional to the expected kinetic energy based on its distribution. Identical for Maxwell-Boltzmann statistics, these temperatures differ in non-Maxwellian statistics when a force is present. Fourier’s law of conduction and entropy should be expressed using statistical temperature, not kinetic temperature. Kinetic temperature is always scalar but statistical temperature and statistical entropy in non-transitive systems have circulation, thereby allowing continuous and circular heat flow. Entropy is relative to underlying statistics, in analogy to the Kullback-Leibler divergence in information theory. The H-theorem, limited by assumptions of homogeneity and indistinguishability, only covers statistically homogeneous systems. The theorem does not cover non-transitive, statistically heterogeneous systems combining different distributions such as Maxwell-Boltzmann, biased half-Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein. The second law can be preserved if generalized by expressing it in terms of statistical temperature and statistical entropy.展开更多
A new Shear Stress Transport(SST)k-ω model is devised to integrate salient features of both the non-transitional SST k-ω model and correlation-based γ-Re_(θ) transition model.An exceptionally simplified approach i...A new Shear Stress Transport(SST)k-ω model is devised to integrate salient features of both the non-transitional SST k-ω model and correlation-based γ-Re_(θ) transition model.An exceptionally simplified approach is applied to extend the New SST(NSST)model capabilities toward transition/non-transition predictions.Bradshaw’s stress-intensity factor R_(b)=|-uv|/k can be parameterized with the wall-distance dependent Reynolds number Re_(y)=√ky/v;however,as the Re_(y)is replaced by a“flow-structure-adaptive”parameter R_(μ)=v_(T)/v,the resulting R_(b)is capable of capturing various transition phenomena naturally.The prospective stress-intensity parameter R_(b)=R_(b)(Re_(y),R_(μ))is incorporated in the constitutive relations for eddy-viscosity v_(T) and production term P_(k).The proposed formulation is intrinsically plausible,having a dramatic impact on the prediction of bypass,separation-induced and natural transitions together with non-transitional flows.An extra viscous-production term P_(k)^(lim) is added with the k-equation to ensure proper generation of k at the viscous sublayer when computing separation-induced transition over a Low-Reynolds Number(LRN)airfoil.Results demonstrate that the NSST k-ω model maintains an excellent consistency with both SST k-ω and γ-Re_(θ) models.展开更多
CO_(2)fixation is important for reducing the greenhouse effect and improving clean energy use.While recent studies focus on converting CO_(2)to liquid fuels,direct fixation into high-value compounds like aromatic carb...CO_(2)fixation is important for reducing the greenhouse effect and improving clean energy use.While recent studies focus on converting CO_(2)to liquid fuels,direct fixation into high-value compounds like aromatic carboxylic acids provides an alternative path.Herein,we report a general electrochemical CO_(2)fixation to aromatic carboxylic acids via the CO_(2)^(·-)intermediate using a non-transition metal graphite electrode.Different from the conventional aromatic radical mechanism,in this report,CO_(2)will gain electrons on the graphite electrode to generate CO_(2)^(·-),which will further attack aromatic halides to obtain the desired aromatic carboxylic acid via an aromatic nucleophilic substitution mechanism.As CO_(2)^(·-)acts as the general intermediate,various aromatic compounds can be carbonylated without the need for a specific catalytic design to activate the aromatic halides.Furthermore,benefit from the CO_(2)^(·-)nucleophile,only the ipso-products can be obtained compared with the conventional approaches.This method offers a flexible way to convert the greenhouse gas CO_(2)into valuable aromatic carboxylic acids,which have applications in pharmaceutical chemistry,biochemistry and polymer chemistry.Therefore,it holds the potential for furthering the objectives of carbon neutrality and green chemistry.展开更多
Using a four-parameter model based on extended Miedema’ s cellular model of alloy phases and pattern recognition methods, the regularities of formation of ternary intermetallic compounds between non-transition metals...Using a four-parameter model based on extended Miedema’ s cellular model of alloy phases and pattern recognition methods, the regularities of formation of ternary intermetallic compounds between non-transition metals have been investigated. The criterion of formation can be expressed as some empirical functions of Φ (electronegativity), nws1/3( valence electron density in Wagn-er-Seitz cell), R (Pauling’s metallic radius) and Z (number of valence electrons in atom).展开更多
A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between...A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between tran-sition element and non-transition element. The formation criterion can be expressed as some inequities of electronega-tivity , the valence electron density in Wagner-Seitz cell nws1/3, Pauling’s metallic radius R and the number of valence electrons in atom Z or their functions. According to these empirical criterions, the 'unknown' binary alloy system can be predicted, the predicted result is better than that of Miedema’s two-parameter model.展开更多
文摘Does non-transitivity in information theory have an analog in thermodynamics? A non-transitive game, “Swap”, is used as a toy thermodynamic model to explore concepts such as temperature, heat flow, equilibrium and entropy. These concepts, found to be inadequate for non-transitive thermodynamic, need to be generalized. Two kinds of temperatures, statistical and kinetic, are distinguished. Statistical temperature is a parameter in statistical distributions. Kinetic temperature is proportional to the expected kinetic energy based on its distribution. Identical for Maxwell-Boltzmann statistics, these temperatures differ in non-Maxwellian statistics when a force is present. Fourier’s law of conduction and entropy should be expressed using statistical temperature, not kinetic temperature. Kinetic temperature is always scalar but statistical temperature and statistical entropy in non-transitive systems have circulation, thereby allowing continuous and circular heat flow. Entropy is relative to underlying statistics, in analogy to the Kullback-Leibler divergence in information theory. The H-theorem, limited by assumptions of homogeneity and indistinguishability, only covers statistically homogeneous systems. The theorem does not cover non-transitive, statistically heterogeneous systems combining different distributions such as Maxwell-Boltzmann, biased half-Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein. The second law can be preserved if generalized by expressing it in terms of statistical temperature and statistical entropy.
基金supported by Hangzhou Dianzi University Research Supporting Fund of Zhejiang Province,China(No.GK218803299037)。
文摘A new Shear Stress Transport(SST)k-ω model is devised to integrate salient features of both the non-transitional SST k-ω model and correlation-based γ-Re_(θ) transition model.An exceptionally simplified approach is applied to extend the New SST(NSST)model capabilities toward transition/non-transition predictions.Bradshaw’s stress-intensity factor R_(b)=|-uv|/k can be parameterized with the wall-distance dependent Reynolds number Re_(y)=√ky/v;however,as the Re_(y)is replaced by a“flow-structure-adaptive”parameter R_(μ)=v_(T)/v,the resulting R_(b)is capable of capturing various transition phenomena naturally.The prospective stress-intensity parameter R_(b)=R_(b)(Re_(y),R_(μ))is incorporated in the constitutive relations for eddy-viscosity v_(T) and production term P_(k).The proposed formulation is intrinsically plausible,having a dramatic impact on the prediction of bypass,separation-induced and natural transitions together with non-transitional flows.An extra viscous-production term P_(k)^(lim) is added with the k-equation to ensure proper generation of k at the viscous sublayer when computing separation-induced transition over a Low-Reynolds Number(LRN)airfoil.Results demonstrate that the NSST k-ω model maintains an excellent consistency with both SST k-ω and γ-Re_(θ) models.
基金supported by the National Key Research and Development Program of China(2022YFC2105904)the National Natural Science Foundation of China(22478043,22090030,52021004,U21A20312,22075033)。
文摘CO_(2)fixation is important for reducing the greenhouse effect and improving clean energy use.While recent studies focus on converting CO_(2)to liquid fuels,direct fixation into high-value compounds like aromatic carboxylic acids provides an alternative path.Herein,we report a general electrochemical CO_(2)fixation to aromatic carboxylic acids via the CO_(2)^(·-)intermediate using a non-transition metal graphite electrode.Different from the conventional aromatic radical mechanism,in this report,CO_(2)will gain electrons on the graphite electrode to generate CO_(2)^(·-),which will further attack aromatic halides to obtain the desired aromatic carboxylic acid via an aromatic nucleophilic substitution mechanism.As CO_(2)^(·-)acts as the general intermediate,various aromatic compounds can be carbonylated without the need for a specific catalytic design to activate the aromatic halides.Furthermore,benefit from the CO_(2)^(·-)nucleophile,only the ipso-products can be obtained compared with the conventional approaches.This method offers a flexible way to convert the greenhouse gas CO_(2)into valuable aromatic carboxylic acids,which have applications in pharmaceutical chemistry,biochemistry and polymer chemistry.Therefore,it holds the potential for furthering the objectives of carbon neutrality and green chemistry.
文摘Using a four-parameter model based on extended Miedema’ s cellular model of alloy phases and pattern recognition methods, the regularities of formation of ternary intermetallic compounds between non-transition metals have been investigated. The criterion of formation can be expressed as some empirical functions of Φ (electronegativity), nws1/3( valence electron density in Wagn-er-Seitz cell), R (Pauling’s metallic radius) and Z (number of valence electrons in atom).
文摘A four-parameter model based on the extended Miedema’s cellular model of alloy phases and pattern recognition methods has been used to study the regularities of the formation of binary intermetallic compounds between tran-sition element and non-transition element. The formation criterion can be expressed as some inequities of electronega-tivity , the valence electron density in Wagner-Seitz cell nws1/3, Pauling’s metallic radius R and the number of valence electrons in atom Z or their functions. According to these empirical criterions, the 'unknown' binary alloy system can be predicted, the predicted result is better than that of Miedema’s two-parameter model.
