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Two innovative equivalent statements of the third law of thermodynamics
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作者 陈晓航 周颖慧 陈金灿 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期324-328,共5页
It is found from textbooks and literature that there are three different statements for the third law of thermodynamics,i.e., the Nernst theorem, the unattainability statement of absolute zero temperature, and the hea... It is found from textbooks and literature that there are three different statements for the third law of thermodynamics,i.e., the Nernst theorem, the unattainability statement of absolute zero temperature, and the heat capacity statement. It is pointed out that such three statements correspond to three thermodynamic parameters, which are, respectively, the entropy,temperature, and heat capacity, and can be obtained by extrapolating the experimental results of different parameters at ultralow temperatures to absolute zero. It is expounded that because there is no need for additional assumptions in the derivation of the Nernst equation, the Nernst theorem should be renamed as the Nernst statement. Moreover, it is proved that both the Nernst statement and the heat capacity statement are mutually deducible and equivalent, while the unattainability of absolute zero temperature is only a corollary of the Nernst statement or the heat capacity statement so that it is unsuitably referred to as one statement of the third law of thermodynamics. The conclusion is that the Nernst statement and the heat capacity statement are two equivalent statements of the third law of thermodynamics. 展开更多
关键词 Nernst statement heat capacity statement Nernst theorem absolute zero temperature the third law of thermodynamics
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Confirmation of the First Law of Thermodynamics in Theory and Extended Bernoulli Equation
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作者 Chengshu Jin 《Journal of Applied Mathematics and Physics》 2023年第2期409-420,共12页
The internal energy change of ideal gas does not depend on the volume and pressure. The internal energy change of real gas has not any relation with the volume and pressure, which had been proved. If the internal ener... The internal energy change of ideal gas does not depend on the volume and pressure. The internal energy change of real gas has not any relation with the volume and pressure, which had been proved. If the internal energy change had not any relation with the volume and pressure, we could confirm the first law of thermodynamics in theory. Simultaneously, the internal energy change is the state function that shall be able to be proved in theory. If the internal energy change depended on the volume and pressure, we could not prove that the internal energy change is the state function and the chemical thermodynamics theory is right. The extended or modified Bernoulli equation can be derived from the energy conservation law, and the internal energy change, heat, and friction are all considered in the derivation procedure. The extended Bernoulli equation could be applied to the flying aircraft and mechanical motion on the gravitational field, for instance, the rocket and airplane and so on. This paper also revises some wrong ideas, viewpoints, or concepts about the thermodynamics theory and Bernoulli equation. 展开更多
关键词 First law of thermodynamics Chemical thermodynamics Bernoulli Equation Static Pressure Head FRICTION
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Energy and first law of thermodynamics for Born-Infeld-anti-de-Sitter black hole 被引量:1
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作者 魏益焕 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第9期212-216,共5页
We calculate the local energy and the energy density of the Reisner-Norstrom-anti-de-Sitter black hole, study the first law of thermodynamics and show the Smarr formula for the Born-Infeld-anti-de-Sitter black hole. A... We calculate the local energy and the energy density of the Reisner-Norstrom-anti-de-Sitter black hole, study the first law of thermodynamics and show the Smarr formula for the Born-Infeld-anti-de-Sitter black hole. Applying the first law of thermodynamics to the black hole region, we analyse the three energy exchange processes between the black hole region and the outer and the inner regions. 展开更多
关键词 first law of thermodynamics energy distribution energy exchange
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Effective first law of thermodynamics of black holes with two horizons
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作者 魏益焕 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第2期821-824,共4页
For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Be... For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Bekenstein-Smarr formula and the effective first law of thermodynamics are derived. 展开更多
关键词 outer and inner horizons effective thermodynamic quantities first law of thermodynamics
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Effects of the porous medium and water-silver biological nanofluid on the performance of a newly designed heat sink by using first and second laws of thermodynamics
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作者 Amin Shahsavar Sajad Entezari +1 位作者 Davood Toghraie Pouya Barnoon 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第11期2928-2937,共10页
The aim of this numerical investigation is to evaluate the laminar forced convection of biologically synthesized water-silver nanofluid through a heat sink(HS)filled with porous foam(PHS)using first and second laws of... The aim of this numerical investigation is to evaluate the laminar forced convection of biologically synthesized water-silver nanofluid through a heat sink(HS)filled with porous foam(PHS)using first and second laws of thermodynamics.The impacts of inlet velocity(V=0.5–3 m·s^-1)and volume fraction of nanofluid(φ=0–1%)on the performance metrics of HS are assessed and the outcomes are compared with those of the non-porous HS(NHS).The outcomes revealed that for both the PHS and NHS,the increase of V causes an intensification in convection coefficient,pumping power,and entropy generation due to fluid friction,while the maximum CPU temperature,thermal resistance,and entropy generation due to the heat transfer reduces by boosting V.Also,it was found that the augmentation of V results in intensification in convection coefficient,pumping power,overall hydrothermal performance,and frictional entropy generation,while the opposite is true for maximum CPU temperature,thermal resistance,and thermal entropy generation.Furthermore,it was reported that,except forφ=0.5%,the overall hydrothermal performance of NHS is better than that of PHS,while PHS has better second-law performance than NHS in all the studied cases.Also,it can be concluded that the best hydrothermal performance for PHS belongs toφ=1%and V=0.5 m·s^-1,while for NHS,these values are 1%and 2 m·s^-1. 展开更多
关键词 Porous medium Heat sink First and second laws of thermodynamics Biologically prepared water-silver nanofluid
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Living Matter and the Laws of Thermodynamics for the Biosphere
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作者 Nabil H.Swedan 《Journal of Geological Research》 2019年第2期35-40,共6页
The laws of thermodynamics have been developed for inert matter,and living matter has not been considered as a variable in these laws.Living matter possesses properties that have had major effects on biosphere evoluti... The laws of thermodynamics have been developed for inert matter,and living matter has not been considered as a variable in these laws.Living matter possesses properties that have had major effects on biosphere evolution with time.The zeroth property is“Living matter is produced from living matter only.”The first property may be summarized as“Living matter occupies the available spaces to the maximum extent when environmental conditions are favorable and no obstacles are present.”And the second property is“Living matter mutates,changes,and adapts to maintain the continuity of life and size as large as possible when environmental conditions are unfavorable.”While the zeroth property is objective in nature,the first and second properties are subjective,in that they are driven by internal stimuli characterizing living matter.Their interaction with the laws of thermodynamics may be thought of as“philosophy intertwining with science.”Accordingly,the laws of thermodynamics are revised to factor in life as a variable.Mathematical expressions of the first and second laws are derived and some of their applicability to the biosphere and climate is explained and discussed.The main conclusion is that life changes climates and the fabric of the biosphere. 展开更多
关键词 laws of thermodynamics BIOSPHERE PHOTOSYNTHESIS Past climates Surface geology
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Motoyosi Sugita—A “Widely Unknown” Japanese Thermodynamicist Who Explored the 4th Law of Thermodynamics for Creation of the Theory of Life
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作者 Kazumoto Iguchi 《Open Journal of Biophysics》 2016年第4期125-232,共109页
The purpose of this paper is to introduce to you, the Western people, nowadays a “widely unknown” Japanese thermodynamicist by the name of Motoyosi Sugita and his study on the thermodynamics of transient phenomena a... The purpose of this paper is to introduce to you, the Western people, nowadays a “widely unknown” Japanese thermodynamicist by the name of Motoyosi Sugita and his study on the thermodynamics of transient phenomena and his theory of life. This is because although he was one of the top theoretical physicists in Japan before, during and after WWII and after WWII he promoted the establishment of the biophysical society of Japan as one of the founding members, he himself and his studies themselves have seemed to be totally forgotten nowadays in spite that his study was absolutely important for the study of life. Therefore, in this paper I would like to present what kind of person he was and what he studied in physics as a review on the physics work of Motoyosi Sugita for the first time. I will follow his past studies to introduce his ideas in theoretical physics as well as in biophysics as follows: He proposed the bright ideas such as the quasi-static change in the broad sense, the virtual heat, and the field of chemical potential etc. in order to establish his own theory of thermodynamics of transient phenomena, as the generalization of the Onsager-Prigogine’s theory of the irreversible processes. By the concept of the field of chemical potential that acquired the nonlinear transport, he was seemingly successful to exceed and go beyond the scope of Onsager and Prigogine. Once he established his thermodynamics, he explored the existence of the 4th law of thermodynamics for the foundation of theory of life. He applied it to broad categories of transient phenomena including life and life being such as the theory of metabolism. He regarded the 4th law of thermodynamics as the maximum principle in transient phenomena. He tried to prove it all life long. Since I have recently found that his maximum principle can be included in more general maximum principle, which was known as the Pontryagin’s maximum principle in the theory of optimal control, I would like to explain such theories produced by Motoyosi Sugita as detailed as possible. And also I have put short history of Motoyosi Sugita’s personal life in order for you to know him well. I hope that this article helps you to know this wonderful man and understand what he did in the past, which was totally forgotten in the world and even in Japan. 展开更多
关键词 Unknown Japanese Thermodynamicist Motoyosi Sugita thermodynamics of Transient Phenomena Virtual Heat Broad Quasi-Static Change Chemical Potential Field of Chemical Potential Diffusion Phenomena Number of Partition Dissipation Function Onsager’s Theory of Irreversible Processes Prigogine’s Least Production of Entropy 4th law of thermodynamics Maximum Principle Pontryagin’s Maximum Principle Bellman’s Optimality Principle Theory of Metabolism Theory of Life CYBERNETICS
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Applications of a Single Molecule Theory of Protein Dynamics
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作者 Yi Fang 《Journal of Biosciences and Medicines》 2024年第6期311-335,共25页
A single molecule theory for protein dynamics has been developed since 2012. It consists of the concepts of conformational Gibbs free energy function (CGF) and single molecule thermodynamic hypothesis (STH) that claim... A single molecule theory for protein dynamics has been developed since 2012. It consists of the concepts of conformational Gibbs free energy function (CGF) and single molecule thermodynamic hypothesis (STH) that claims that all stable conformations are (local or global) minimizers of CGF. These are enough to give a unified explanations and mechanisms to many aspects of protein dynamics such as protein folding;allostery;denaturation;and intrinsically disordered proteins. Formulas of CGF in water environment had been derived via quantum statistics. Applications of them to soluble proteins are: docking Gibbs free energy difference formula and a practical way to search better docking site;single molecule binding affinity;predicting and explaining why structures of a monomeric globular protein looks like a globule and is tightly packed with a hydrophobic core;a representation of the hydrophobic effect;and a wholistic view to structures of water soluble proteins. 展开更多
关键词 FOLDING DENATURATION BINDING Post-Binding Deformation ALLOSTERY Dynamic Second law of thermodynamics
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Preliminary analyses of the dynamics and thermodynamics of rotating regular black holes
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作者 杨昊 余长江 缪炎刚 《Chinese Physics C》 SCIE CAS CSCD 2024年第7期191-210,共20页
We investigate the dynamic and thermodynamic laws governing rotating regular black holes.By analyzing dynamic properties,i.e.,the interaction between scalar particles and rotating regular black holes,we establish the ... We investigate the dynamic and thermodynamic laws governing rotating regular black holes.By analyzing dynamic properties,i.e.,the interaction between scalar particles and rotating regular black holes,we establish the criteria that determine whether such black holes satisfy the laws of thermodynamics.In addition,we provide the general form of conserved quantities related to rotating regular black holes,including the relevant flows associated with neutral scalar particles.Meanwhile,we reexamine the relationship between the third law of thermodynamics and weak cosmic censorship conjecture for rotating regular black holes.Based on the abovementioned criteria,we discuss the laws of thermodynamics for three models of rotating regular black holes:Rotating Hayward black holes,Kerr black-bounce solutions,and loop quantum gravity black holes.Our findings indicate that none of the three models satisfies the first law of thermodynamics.In particular,the first and third models fail to comply with the three laws of thermodynamics,whereas the second model satisfies only the second and third laws of thermodynamics.Finally,we attempt to rescue the laws of thermodynamics by modifying entropy or extending the phase space.However,the two scenarios cannot ensure the three laws of thermodynamics in the three models,which reveals an unusual property of rotating regular black holes. 展开更多
关键词 rotating regular black holes thermodynamics laws of black holes weak cosmic censorship conjecture
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The Validity of the Thermohydrogravidynamic Theory Concerning the Predicted Dates of the Maximal Temporal Intensifications of the Global Seismotectonic Processes of the Earth during the Range 2020 - 2023 AD
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作者 Sergey V. Simonenko 《Journal of Geoscience and Environment Protection》 2023年第7期242-255,共14页
We present (on the 13<sup>th</sup> International Conference on Geology and Geophysics) the convincing evidence that the strongest earthquakes (according to the U.S. Geological Survey) of the Earth (during ... We present (on the 13<sup>th</sup> International Conference on Geology and Geophysics) the convincing evidence that the strongest earthquakes (according to the U.S. Geological Survey) of the Earth (during the range 2020 - 2023 AD) occurred near the predicted (calculated in advance based on the global prediction thermohydrogravidynamic principles determining the maximal temporal intensifications of the global seismotectonic, volcanic, climatic and magnetic processes of the Earth) dates 2020.016666667 AD (Simonenko, 2020), 2021.1 AD (Simonenko, 2019, 2020), 2022.18333333 AD (Simonenko, 2021), 2023.26666666 AD (Simonenko, 2022) and 2020.55 AD, 2021.65 AD (Simonenko, 2019, 2021), 2022.716666666 AD (Simonenko, 2022), respectively, corresponding to the local maximal and to the local minimal, respectively, combined planetary and solar integral energy gravitational influences on the internal rigid core of the Earth. We present the short-term thermohydrogravidynamic technology (based on the generalized differential formulation of the first law of thermodynamics and the first global prediction thermohydrogravidynamic principle) for evaluation of the maximal magnitude of the strongest (during the March, 2023 AD) earthquake of the Earth occurred on March 16, 2023 AD (according to the U.S. Geological Survey). . 展开更多
关键词 Thermohydrogravidynamic Theory Non-Stationary Cosmic Gravitation Generalized First law of thermodynamics Cosmic Geology Cosmic Geophysics Cosmic Seismology Global Seismotectonic Processes Global Prediction Thermohydrogravidynamic Principles The Short-Term Thermohydrogravidynamic Technology
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Mathematical Model to Elaborate the Table of Thermodynamic Properties 被引量:1
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作者 Debrayan Bravo Hidalgo Liliana Del Carmen Morillo Acosta Nancy Del Rocio Flores Hinojosa 《Journal of Applied Mathematics and Physics》 2022年第6期1951-1967,共17页
Purpose: The aim of this scientific contribution is to show the potential that integral calculus has offered to the analysis of thermodynamic processes. Method: Application of Integral Calculus. In this context, the d... Purpose: The aim of this scientific contribution is to show the potential that integral calculus has offered to the analysis of thermodynamic processes. Method: Application of Integral Calculus. In this context, the document covers the theoretical principles of integral calculus, such as Theoretical framework and background, Geometric interpretation of the primitive, Primitive existence theorem. Results: Integral calculus and generalized thermodynamic models, and their applications in various thermodynamic analysis contacts such as the Generalized Enthalpy Model, the Generalized Entropy Model, and the Generalized Model applied to gas mixtures and the General Model to elaborate the properties table. Conclusion: The mathematical analysis developed in this document is very useful in engineering and applied physics environments, a fact that supports its common pedagogical practice in university institutions. 展开更多
关键词 Equations Curves of Thermal Processes Thermodynamic laws Physics-Mathematics Energy
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Hawking radiation as tunnelling from arbitrarily dimensional Reissner-Nordstrom de Sitter black hole 被引量:1
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作者 蒋青权 杨树政 吴双清 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第11期2523-2528,共6页
This paper extends Parikh-Wilzcek's recent work, which treats the Hawking radiation as a semi-classical tunnelling process from the event horizon of four dimensional Schwarzshild and Reissner-Nordstrom black holes, t... This paper extends Parikh-Wilzcek's recent work, which treats the Hawking radiation as a semi-classical tunnelling process from the event horizon of four dimensional Schwarzshild and Reissner-Nordstrom black holes, to that of arbitrarily dimensional Reissner-Nordstrom de Sitter black hole. The result shows that the tunnelling rate is related to the change of Bekenstein-Hawking entropy and the factually radiant spectrum is no longer precisely thermal after taking the dynamical black hole background and energy conservation into account, but is consistent with the underlying unitary theory and then satisfies the first law of the black hole thermodynamics. Meanwhile, in Parikh-Wilzcek's framework, this paper points out that the information conservation is only suitable for the reversible process but in highly unstable evaporating black hole (irreversible process) the information loss is possible. 展开更多
关键词 black hole radiation tunnelling rate Bekenstein-Hawking entropy first law of the black hole thermodynamics
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IMPROVEMENT OF A GLOBAL SPECTRAL MODEL BY INTRODUCING THE SECONDLAW OF THERMODYNAMICS
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作者 柳崇健 张道民 +1 位作者 李金龙 纪立人 《Acta meteorologica Sinica》 SCIE 1995年第1期95-100,共6页
The second law of thermodynamics has never been taken into account in the traditional hydrodynamics and numer- ical weather prediction models,which is a serious oversight in the history of mechanics.Introducing the th... The second law of thermodynamics has never been taken into account in the traditional hydrodynamics and numer- ical weather prediction models,which is a serious oversight in the history of mechanics.Introducing the thermodynamic irreversibility into the hydrodynamic systems,the theory and method proposed in this study would not only lead the outputs of a numerical weather prediction model to noticeable improvement,but lead the structure of hydrodynamics to deepgoing transformation. 展开更多
关键词 the second law of thermodynamics numerical weather prediction HYDRODYNAMICS
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Thermal properties of Lense-Thirring spacetime in tetrad theory of gravity
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第8期51-58,共8页
Using the divergence term appearing in the Lagrangian of the teleparallel equivalent of general relativity (TEGR), we calculate the thermodynamic quantities of four tetrads' spacetime reproducing Lense-Thirring (L... Using the divergence term appearing in the Lagrangian of the teleparallel equivalent of general relativity (TEGR), we calculate the thermodynamic quantities of four tetrads' spacetime reproducing Lense-Thirring (LT) metric. We also investigate the first law of thermodynamics and the quantum statistical relation. 展开更多
关键词 Euclidean continuation method thermodynamic quantities first law of thermodynamic quantum statistical relation
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Thermal properties of regular black hole with electric charge in Einstein gravity coupled to nonlinear electrodynamics
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作者 魏益焕 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第12期113-117,共5页
We propose a regular spherically symmetric spacetime solution with three parameters in Einstein gravity coupled to nonlinear electrodynamics(NED), which describes the NED black hole with electric charge. It is found t... We propose a regular spherically symmetric spacetime solution with three parameters in Einstein gravity coupled to nonlinear electrodynamics(NED), which describes the NED black hole with electric charge. It is found that the system enclosed by the horizon of NED spacetime satisfies the first law of thermodynamics. In order to obtain the NED spacetime with only electric charge, the case of two parameters taking the same value is considered. In this case, we express the mass of the NED spacetime as a function of the entropy and electric charge of the NED black hole, give the Smarr-like formula and the approximate Smarr formula for the mass of NED spacetime. 展开更多
关键词 regular nonlinear electrodynamics(NED) spacetime NED black hole with electric charge first law of thermodynamics Smarr formula
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THE UNIFIED ELASTIC-VISCOSIC-PLASTIC THEORY OF SOLIDS
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作者 金问鲁 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第3期254-261,共8页
In this paper, mt unified elastic-viscosic-plastic theory which can compute the change of elastic, viscosic and plastic state of each point in the body is proposed. The theory is based on the laws of thermodynamics an... In this paper, mt unified elastic-viscosic-plastic theory which can compute the change of elastic, viscosic and plastic state of each point in the body is proposed. The theory is based on the laws of thermodynamics and the pseudo elastic postulate. lit the paper, the constitutive equations and variational principles are deduced. From which, the finite element method of both space and time may be easily formulated. Note that, by choosing the material parameters properly, the plastic constitutive equations currently used may be given. 展开更多
关键词 the first and second laws of thermodynamics pseudo elastic postulate
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New Method Proving Clausius Inequality
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作者 Chengshu Jin 《Journal of Modern Physics》 2020年第10期1576-1588,共13页
It is impossible that proving the internal energy change has the relations with volume and pressure. About the second law of thermodynamics, many mistakes of formulations need to be put right and modified, and many ne... It is impossible that proving the internal energy change has the relations with volume and pressure. About the second law of thermodynamics, many mistakes of formulations need to be put right and modified, and many new concepts are surveyed too. The equality and inequality on the ratios of internal energy change to temperature and work to temperature are discussed. The relation between the reversible paths and their realistic paths is also researched. In an isothermal process, the internal energy change for the gases is equal to zero, but the internal energy change is not equal to zero for the phase transition or chemical reaction. The Clausius inequality can be derived from the equation calculating the internal energy change in mathematics;it is the new method proving the Clausius inequality. These change laws of thermodynamics could be applied to the gravitational field and mechanical motion and so on. 展开更多
关键词 First law of thermodynamics Clausius Inequality Internal Energy Change Chemical Reaction Gravitational Field
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The Confirmed Validity of the Explanatory Aspect of the Thermohydrogravidynamic Theory Concerning the Evaluated Maximal Magnitude of the Strongest Earthquake of the Earth near the Predicted Date 2021.1 AD during the Range from October 27, 2020 to May 17, 2021 AD 被引量:1
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作者 Sergey V. Simonenko 《Journal of Geoscience and Environment Protection》 2022年第7期319-330,共12页
We present the explanation (in the frame of the established thermohydrogravidynamic technology) of the maximal magnitude M = 8.1 (according to the U.S. Geological Survey) of the strongest earthquake of the Earth occur... We present the explanation (in the frame of the established thermohydrogravidynamic technology) of the maximal magnitude M = 8.1 (according to the U.S. Geological Survey) of the strongest earthquake of the Earth occurred in Kermadec Islands, New Zealand on March 4, 2021 AD (during the considered range from October 27, 2020 to May 17, 2021 AD). This strongest earthquake occurred near the calculated date 2021.1 AD corresponding (in the frame of the thermohydrogravidynamic theory) to the local maximal combined planetary and solar integral energy gravitational influence on the internal rigid core of the Earth. To obtain this explanation, we have analyzed the strongest earthquakes of the Earth (according to the U.S. Geological Survey) occurred near the dates of the local maximal combined planetary and solar integral energy gravitational influences on the internal rigid core of the Earth. 展开更多
关键词 Thermohydrogravidynamic Theory Non-Stationary Cosmic Gravitation Gen-eralized First law of thermodynamics Cosmic Geology Cosmic Geophysics Cosmic Seismology Global Seismotectonic Processes Global Prediction Thermohydrogravidynamic Principles Thermohydrogravidynamic Technology
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Thermodynamic second law analysis of magneto-micropolar fluid flow past nonlinear porous media with non-uniform heat source
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作者 E.O.Fatunmbi S.O.Salawu 《Propulsion and Power Research》 SCIE 2020年第3期281-288,共8页
This study analyzes the second law of thermodynamic for entropy generation in an irreversible hydromagneto-micropolar flow system with non-homogenous heat generation.The non-symmetric microstructure fluid flow past a ... This study analyzes the second law of thermodynamic for entropy generation in an irreversible hydromagneto-micropolar flow system with non-homogenous heat generation.The non-symmetric microstructure fluid flow past a stretching sheet with saturated porous nonlinear media under magnetic field influence.Ignoring the fluid particle deformation,the microstructure is assumed rigid with the viscous suspended medium.The reduced dimensionless nonlinear formulated model is computationally coded and solved to obtain solutions for the entropy volumetric production,Bejan number and heat transfer magneto-micropolar fluid.The parameter dependent solutions for the flow characteristics and irreversibility processes are plotted and discussed.It is revealed from the study that minimization of entropy generation in a magneto-micropolar flow system is possible by improving the thermodynamic equilibrium with low material variables,viscosity and hysteresis magnetic.Also,it is seen that the terms that encourage internal heat generation reduces the micropolar fluid viscosity in the system. 展开更多
关键词 MICROPOLAR Non-Newtonian fluid Entropy generation Stretching sheet Thermodynamic law
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Entropies of the various components of the universe
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作者 喻豪 刘玉孝 李瑾 《Chinese Physics C》 SCIE CAS CSCD 2023年第5期239-258,共20页
In this study, we investigate the entropies of photons, ideal gas-like dust(baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we ca... In this study, we investigate the entropies of photons, ideal gas-like dust(baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and conditions, the entropies of these components can satisfy the second law of thermodynamics independently. Our calculations show that the specific entropy of matter cannot be a constant during the expansion of the universe, except for photons. When these components interact with the space-time background, particle production(annihilation) can occur. We study the influence of the interaction on the entropies of these components and obtain the conditions guaranteeing that the entropy of each component satisfies the second law of thermodynamics. 展开更多
关键词 entropy of universe dark enengy DUST PHOTON the second law of thermodynamics
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