arXiv subjects

Jiulin Du

Publications and source records attributed to Jiulin Du.

At least 37 records · Page 2Linked to original sources

arXiv2020

The diffusion of charged particles in the weakly ionized plasma with power-law kappa-distributions

We study the diffusion of charged particles in the weakly ionized plasma with the power-law kappa-distributions and without magnetic field. The electrons and ions have different kappa-parameters. We obtain the expressions of both diffusion and mobility coefficients of electrons and ions respectively in the plasma. We find that these new transport coefficient formulae depend strongly on the kappa-parameters in the power-law distributed plasma. When we take kappa to be infinite, these formulae reduce to the classical forms in the weakly ionized plasma with a Maxwellian distribution.

physics.plasm-ph↗

arXiv2019

Effect of magnetic field on viscosity in the weakly ionized and magnetized plasma with power-law q-distributions in nonextensive statiostics

We study the effect of magnetic field on the viscosity of charged particles in the weakly ionized and magnetized plasma with the power-law q-distributions by using the generalized Boltzmann equation of transport in nonextensive statistics. We derive six viscosity coefficients of electrons and ions in the complex plasma, including the magnetic field introduced four viscosity coefficients, where the q-parameter and magnetic field both play significant roles. By numerical analyses, we show that these viscosity coefficients depend strongly on the magnetic field and q-parameters of the weakly ionized and magnetized plasma, and so have potential applications in low temperature complex plasmas.

physics.plasm-ph↗

arXiv2019

The current density and transport coefficients in the fully ionized plasma with q-distributions in nonextensive statistics

We study the current density and transport coefficients in the fully ionized plasma with the q-distributions in nonextensive statistics and in strong magnetic field. By using the generalized Boltzmann transport equation in nonextensive statistics, we derive the current density and the expressions of the transport coefficients, including the conductivity, the thermoelectric coefficient, the Hall coefficient, and the Nernst coefficient. It is shown that these new transport coefficients has been generalized to the nonequilibrium complex plasmas with q-distributions in nonextensive statistics, which depend strongly on the q-parameters and when we take the limit q to 1, they perfectly return to those for the plasma based on a Maxwellian distribution.

physics.plasm-ph↗

arXiv2019

Diffusion and heat conductivity in the weakly ionized plasma with power-law q-distributions in nonextensive statistics

We study the diffusion and thermal conductivity of charged particles in the weakly ionized plasma with the power-law q-distributions in nonextensive statistics and without the magnetic field. Electrons and ions have different q-parameters and temperature. We derive new expressions of the diffusion, thermal diffusion, thermal conductivity and thermoelectric coefficients of electrons and ions respectively in the plasma. It is shown that these transport coefficients depend significantly on the q-parameters in the power-law q-distributed plasma and thus they have different properties from those derived in the traditional statistics with a Maxwellian distribution.

physics.plasm-ph↗

arXiv2019

Slowing down of charged particles in dusty plasmas with pawer-law kappa-distributions

We study the slowing down of particle beams passing through the dusty plasma with power-law kappa-distributions. Three plasma components, electrons, ions and dust particles, can have different kappa-parameter. We derive the deceleration factor (the velocity moment equation) and the slowing down time of a test particle, and numerically study the slowing down properties of an electron beam, a proton beam and a dust particle beam, respectively, in the kappa-distributed dusty plasma. We show that the slowing down properties of particle beams depend strongly on the kappa-parameters of the plasma components, and the dust component plays a dominant role in the slowing down. And the slowing down also depends on mass and charge of the dust particles in the dusty plasma. More detailed results are shown in 17 numerical graphs.

physics.plasm-ph↗

arXiv2018

A nonextensive approach for understanding the van der Waals' equation

In order to improve the teaching of the course of statistical physics in universities, in this article we introduce nonextensive statistics, a new statistical theory about complex systems. We study the two modification coefficients a and b in the van der Waals' equation in nonextensive statistics and thus understand the possible relation between the van der Waals' equation and the nonextensivity. We express these coefficients when a real gas is regarded as the nonextensive gas and then relate them to the q-parameter in nonextensive statistics. Furthermore, we derive the q-parameter of a real gas, which contain the intermolecular Lennard-Jones potential, but also strongly depend on the state parameter and molecular number of the gas. From the new statistical physics, we show that the nonextensivity plays a significant role in the coefficients of the van der Waals' equation if the gas contains limited number of molecules or the gas is regarded as a few-body system. This article is suitable to read for senior undergraduate students, graduate students and teachers who teach the course of statistical physics in universities.

physics.gen-ph↗

arXiv2018

The viscosity of charged particles in the weakly ionized plasma with power-law distributions

We study the viscosity of light charged particles in weakly ionized plasma with the power-law q-distributions by using the Boltzmann equation of transport and the motion equation of hydrodynamics. The nonequilibrium plasma is considered to be space inhomogeneous and without magnetic field. We derive the expressions of the viscosity coefficients of the electrons and the ions in the q-distributed plasma, including the first and the second viscosity coefficients respectively. It is shown that these new viscosity coefficients depend strongly on the q-parameters, and when we take the limit of q to 1, they perfectly return to those in the plasma with a Maxwellian distribution. The discussions presented in this paper can also be applied to the plasmas with the kappa-distributions.

physics.plasm-ph↗

arXiv2017

The limit behavior of the evolution of Tsallis entropy in self-gravitating systems

In this letter, we study the limit behavior of the evolution of Tsallis entropy in self-gravitating systems. The study is carried out under two different situations, drawing the same conclusion. No matter in the energy transfer process or in the mass transfer process inside the system, when nonextensive parameter q is more than unity, the total entropy is bounded; on the contrary, when this parameter is less than unity, the total entropy is unbounded. There are proofs in both theory and observation that the q is always more than unity. So the Tsallis entropy in self-gravitating system generally exhibits a bounded property. This indicates the existence of global maximum of Tsallis entropy. It is possible for self-gravitating systems to evolve to thermodynamically stable states.

cond-mat.stat-mech↗

arXiv2017

The nonextensive parameter for the rotating astrophysical systems with power-law distributions

We study the nonextensive parameter for the rotating astrophysical systems with power-law distributions, including both the rotating self-gravitating system and the rotating space plasma. We extend the equation of nonextensive parameter to complex system with arbitrary force field, and derive a general equation of the q-parameter, most generally including both the rotating self-gravitating systems and the rotating space plasmas. At the same time, we reproduce the kappa-distribution in space plasmas and obtain equations of the kappa-parameter. We show that the q-parameter is related not only to the temperature gradient, the gravitational force and the electromagnetic force, but also to the inertial centrifugal force and Coriolis force. Thus the rotation introduces significant effect on nonextensivity in the systems. Several examples are given to illustrate the nonextensive effect introduced by the rotation.

cond-mat.stat-mech↗

arXiv2016

Nonextensive thermodynamic relations based on the assumption of temperature duality

The nonextensive thermodynamic relations are expressed under the assumption of temperature duality, endowing the "physical temperature" and the "Lagrange temperature" in different physical sense. Based on this assumption, two sets of parallel Legendre transform structures are given. One is called "physical" set, and the other called "Lagrange" set. In these two formalisms, the thermodynamic quantities and the thermodynamic relations are both liked through the Tsallis factor. Application of the two sets of the thermodynamic relations to the self-gravitating system shows that the heat capacity defined in the classical thermodynamics has no relevance to the stability of the system. Instead, the new defined heat capacity can determine the stability of the system.

cond-mat.stat-mech↗

arXiv2015

The anomalous distributions and Soret coefficient in a nonequilibrium colloid system

The density distributions and Soret coefficient in a nonequilibrium colloidal system with nonuniform temperature are studied by the overdamped Langevin equation for Brownian motion in an inhomogeneous strong friction medium. Based on the relation between the temperature gradient, the interaction potential and the q-parameter in nonextensive statistics, We show that the colloidal particle density can be a function of the temperature and anomalously follows the noted alpha-distribution, or equivalently it can also be a function of the potential energy and follows Tsallis distribution. With the q-parameter we can establish a new formula of the Soret coefficient and thus, bridge the gap between the ideally theoretical Soret coefficient and available experiments.

cond-mat.soft↗

arXiv2015

The precise time-dependent solution of the Fokker-Planck equation with anomalous diffusion

We study the time behavior of the Fokker-Planck equation in Zwanzig rule (the backward-Ito rule) based on the Langevin equation of Brownian motion with an anomalous diffusion in a complex medium. The diffusion coefficient is a function in momentum space and follows a generalized fluctuation-dissipation relation. We obtain the precise time-dependent analytical solution of the Fokker-Planck equation and at long time the solution approaches to a stationary power-law distribution in nonextensive statistics. As a test, numerically we have demonstrated the accuracy and validity of the time-dependent solution.

cond-mat.stat-mech↗

arXiv2014

The stationary state and gravitational temperature in a pure self-gravitating system

The pure self-gravitating system in this paper refers to a multi-body gaseous system where the self-gravity plays a dominant role and the intermolecular interactions can be neglected. Therefore its total mass must be much more than a limit mass, the minimum mass of the system exhibiting long-range nature. Thee method to estimate the limit mass is then proposed. The nonequlibrium stationary state in the system is identical to the Tsallis equilibrium state, at which the Tsallis entropy approaches to its maximum. On basis of this idea, we introduce a new concept of the temperature whose expression includes the gravitational potential and therefore we call it gravitational temperature. Accordingly, the gravitational thermal capacity is also introduced and it can be used to verify the thermodynamic stability of the astrophysical systems.

astro-ph.GA↗

arXiv2014

Two physical explanations of the nonextensive parameter in a self-gravitating system

We present two possible physical explanations of the nonextensive parameter in a self-gravitating system. One is related to the detailed balance in such system. With the detailed balance, the statistical balance of molecular energy is reached, under which the radiation energy "stored" in the molecules becomes important. Then the relation between the nonextensive parameter and the storage coefficient which measures the ability of molecules to store the radiation energy is constructed. The other explanation is from one dimensionless quantity called (logarithmic) temperature gradient defined in the stellar physics. In view of this, we find that in order to keep the nuclear reactions alive inside the Sun, the ratio of radiation pressure to the total pressure in the core must be more than 0.2833.

cond-mat.stat-mech↗

arXiv2014

The adiabatic static linear response function in nonextensive statistical mechanics

We analyze the difference between the three generations of the energy constraint in nonextensive statistical mechanics. Using the third generation of the energy constraint, we revise the isothermal static linear response function and then derive the adiabatic static linear response function under the adiabatic condition. We present the relationship between the isothermal and adiabatic linear response functions.

cond-mat.stat-mech↗

arXiv2014

The power-law reaction rate coefficient for barrierless reactions

The power-law reaction rate coefficient for the barrierless reactions is studied if the reactions take place in systems with power-law distributions, and a generalized rate formula for the barrierless reactions in Gorin model is derived. We show that due to barrierless, different from those for bimolecular and unimolcular reactions, the power-law rate coefficient for the barrierless reactions does not have the factor of power-law distribution function and thus it is not very strongly dependent on the nu-parameter. Four barrierless reactions are taken as the application examples to calculate the new rate coefficients, which with larger fitting nu-parameters can be exactly in agreement with the measurement values in experimental studies.

physics.chem-ph↗

arXiv2014

The power-law TST reaction rate coefficient with tunneling correction

We study the TST reaction rate for the systems with power-law distributions. We derive the expressions of the reaction rate coefficient with tunneling correction, which strongly depends on the power-law parameter. The numerical results show that a small deviation from one in the parameter can result in a significant change in the rate coefficient, but only cause a small change in the tunneling correction. Thus the tunneling correction is not sensitive to the power-law distributions. As an application example, we take the hydrogen reaction to calculate the power-law reaction rate coefficient with the tunneling correction, the results of which with the parameter slightly different from one are in good agreement with all the experimental studies in temperature range 200~1000K.

physics.chem-ph↗

arXiv2014

Entropy production rate of nonequilibrium systems from the Fokker-Planck equation

The entropy production rate of nonequilibrium systems is studied via the Fokker-Planck equation. This approach, based on the entropy production rate equation given by Schnakenberg from a master equation, requires information of the transition rate of the system under study. We obtain the transition rate from the conditional probability extracted from the Fokker-Planck equation and then derive a new and more operable expression for the entropy production rate. Examples are presented as applications of our approach.

cond-mat.stat-mech↗