Li Xiao-qing

Light curves of Asteroids (IV)

Abstract Light curves, based on photoelectric observations made in 1965 and 1978, are given for 11 asteroids. For 7 of them, periods have been determined (TABLE 1). Our period for (16) Psyche is different from some previous determinations.

COUPLING EQUATIONS FOR A FLOW-WAVE FIELD USED TO FACULAE HEATING

In a binary system of a background fluid-wave field, the wave effect may be important in some cases. From general properties of thermodynamics of the medium, we derive the coupling equations for the mean flow-wave field. For six wave modes (Langmuir wave, ion-acoustic oscillations, whistlers, Alfvén waves, magneto-acoustic oscillations, and transverse plasma wave) the corresponding representation of the wave stress tensor is found. Finally, the representation for the Alfvén waves is applied to the faculae heating and a result consistent with observations is obtained.

DYNAMO MECHANISM FOR TURBULENT WAVE IN CELESTIAL BODIES

It is well known that under cosmic conditions the various modes of plasma turbulence waves (including MHD waves) are easily excited. In this paper we are trying to show that the turbulent wave also generates a source-term for the magnetic induced equations as does the turbulent fluid with nonzero helicity. By expanding the turbulent field in Fourier series, we have obtained dynamo equation for turbulent wave and a reasonable solution which indicates that the poloidal field may be built-up in the turbulent source region. Perhaps, we may think that the poloidal field of Equation (9) is the analytical form of the magnetic field in a turbulent source region of celestial bodies.

Radiation and energy loss by monopole in cosmic plasma

Radiation and energy loss by monopole in cosmic plasma are investigated in detail. The general formulae for monopole radiation are derived; the Čerenkov power and spectra radiation differing from ones of charged particles are found; and its energy loss in cosmic plasma and metal is obtained. It is pointed out that it is possible to examine monopole in virtue of the Čerenkov radiation in ordinary medium.

A possible mechanism of nonresonant heating of the chromosphere-corona transition zone

Abstract The steep temperature distribution with height in the solar chromosphere-corona transition zone is one of the unsolved problems in solar physics. This paper presents a qualitative and quantitative explanation to this steep distribution of temperature in terms of the pileup effect of the oscillations in a plasma and the mechanism of wave-particles nonresonant heating. Analysis shows that if a proton beam of high energy is continuously injected into the transition zone from the chromosphere, the steep distribution of temperature is able to appear in a narrow layer through the plasma wave-particles nonlinear interactions.

Formating double layer mechanism by electric charged particle stream in plasma

In this paper, two-fluid equations have been solved after having considered magnetic field generated by charged particle stream. Finally, the distribution of electric field Ez(z, r) and its growth rate γ in plasma have been obtained. From the expression of Ez(z, r) it can be known that the double layer has been formed. With the increase of disturbance γ will be larger, and finally this will result in the interruption of electric current and occurrence of burst.

Alfvén wave-driving mechanism of late-type stellar wind

Because late-type stellar wind has low temperature, massive outflow, and high terminal velocity, theoretical models of thermal pressure or radiation pressure cannot explain the acceleration of late-type stellar wind. Energy damping of Alfvén wave in stellar winds is small, and Alfvén wave is perhaps the driving force of late-type stellar wind if the wave energy-flux is large enough. After theoretical analysis and numerical calculation, we get various velocity distributions by taking various wave energy-fluxes in reliable range, the terminal velocities accord with observations. If late-type stellar winds are driven by thermal pressure, the temperature is higher than acceptable. The results of Alfvén wave driving winds also indicate that massive stellar winds need large energy flux and acceleration is closely related with gravity. In discussion we think that Alfvén wave accelerating late-type stellar wind is feasible and the initial energy-flux, damping of Alfvén wave in stellar winds need further study.

THE RADIATION FEATURES OF THE MOVING CHARGES AND THE EFFECTS SUPPRESSED BY THE COSMIC PLASMAS IN PULSARS AND OTHER CELESTIAL BODIES

In this paper, we have discussed the feature of radiation resulting from the moving magnetic charges in detail. We have pointed out that there is the curvature radiation of the monopoles in pulsars and other celestial bodies, but this radiation can intensely be suppressed by the cosmic plasma.

Integration of Poisson's equation for a disk galaxy of finite thickness

Abstract Assuming a density perturbance in the form of an Archimedes spiral and an exponential decrease of matter density along the z-direction, Poissons equation governing the perturbed gravitational field is solved with Hankels integral transform and the method of steepest descent. For shortwave perturbances in the plane z=0, a simple analytical expression is given. In our approximation, the form of the perturbed field is determinate and is also an Archimedes spiral.

The Fokfer-Planck equapions for magnetic monopoles and charged particles

Abstract We investigate the Fokker-Planck equations (non-relativistic case) for the interaction between magnetic monopoles and charged particles. We find that, the collision integral in this case is also logarithmically divergent, showing that the main effect is still produced by far encounters. We give, for thermal equilibrium, expressions for the three relaxation times. Compared with the well-known expressions for charged particles, these are generally amplified by a factor (light velocity/thermal velocity) 2 , showing that, under ordinary conditions, the interaction between monopoles and charged particles is negligible but that, under certain astrophysical conditions, it is not. In the latter case, the MHD equations must be modified accordingly and the modified equations are given.