望远镜静态指向模型的基本参数

对地平式望远镜静态指出模型的基本参数进行了讨论，给出了一种参数较少，模型稳定的望远镜修正模型，与常用的球谐函修正模型相比较，基本参数模型具有对观测资料分布不敏感，模型的系随资料分布变化较小和修正精度较高优点，并且其残差序列服从正态分布，基本上能够满足高精度定轨的需要。     

Exact Bianchi type-II Lyttleton-Bondi universe

The exterior field of the Bianchi type-II metric in the Lyttleton-Bondi universe is considered and an exact cosmological model is presented. The behaviour of the model is also discussed.     

Exact Bianchi type-II Lyttleton-Bondi universe

The exterior field of the Biachi type-II metric in the Lyttleton-Bondi universe is considered and an exact cosmological model is presented. The behaviour of the model is also discussed.     

Exact Bianchi type-II vacuum-cosmological model in a scalar-tensor theory of gravitation

An exact Bianchi type-II vacuum-cosmological model is obtained in the scalar-tensor theory of gravitation proposed by Dunn. The behaviour of the model is discussed.     

Bianchi type – IX string cosmological models with bulk viscous fluid in general relativity

Some Bianchi Type IX string cosmological models with bulk viscous fluid for massive string is investigated. To get a determinate solution, a supplementary condition a=b ⁿ, between metric potentials, is used wherea and b are function of time alone. A particular solution for n=0 is also discussed. The behaviour of the model in presence and absence of bulk viscosity, is discussed. The physical and implications of the model is also discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

A model for the penumbra of sunspots

A penumbra model in hydrostatic equilibrium is presented. The model accounts for the continuum observations as well as the observations of Fraunhofer lines in the penumbra. The uncertainty in the model in deeper layers is discussed. It is shown that the penumbra is probably not in strict radiative equilibrium.     

Bianchi type-III model in the Lyttleton-Bondi universe

The exterior field of the Bianchi type-III metric in the Lyttleton-Bondi universe is considered and an exact cosmological model is presented. Some physical properties of the model are discussed.     

A gravitationally non-degenerate cosmological model with expanding and shearing viscous fluid in general relativity

The object of this paper is to investigate the behaviour of viscosity in a cosmological model, in which the coefficient of shear viscosity is assumed to be proportional to rate of expansion in the model. The behaviour of the model in the absence of shear viscosity is also discussed.     

Viscous fluid universe filled with stiff fluid in general relativity

We have investigated two stiff-fluid models in which the material distribution is that of viscous fluid. In the first model, the coefficient of shear viscosity is assumed to be constant while in the second model the coefficient of shear viscosity is proportional to the rate of expansion in the model. The paper also discusses some physical and geometrical aspects of the model. The behaviour of the model in absence of viscosity is also discussed.     

Bianchi type-VI0 model in the Lyttleton-Bondi universe

The exterior field of the Bianchi type-VI₀ metric in the Lyttleton-Bondi universe is considered and an exact cosmological model is presented. Some physical properties of the model are discussed.     

Magneto-viscous fluid cosmological model of plane symmetry in general relativity

The object of this paper is to investigate the behaviour of magnetic field in a viscous fluid cosmological model. Various physical and geometrical properties of the model have also been discussed.     

Inflation in Bianchi type-IX Einstein-Cartan Cosmological Model

Within the framework of Einstein-Cartan theory with Weyssenhoff fluid, we investigate an inflation model for an anisotropic Bianchi type-IX cosmological model. The system of field equations is solved numerically and an inflation epoch is achieved. The general condition for the inflation to occur is also discussed. This anisotropic model evolves quickly towards to an isotropic one.     

Tilted Bianchi Type I stiff fluid magnetized cosmological model in general relativity

Tilted Bianchi Type I cosmological model for perfect fluid distribution in presence of magnetic field, is investigated. To get a determinate solution, it has been assumed that the universe is filled with stiff perfect fluid distribution together with A=(BC) ⁿ where A,B,C are metric potentials and n is a constant. The behaviour of the model in presence and absence of magnetic field is discussed. The various physical and geometrical aspects of the model, is also discussed. It has been shown that tilted nature of the Bianchi Type I model is preserved due to magnetic field. This revised version was published online in July 2006 with corrections to the Cover Date.     

Bianchi type-VI0 cosmological model in the general scalar-tensor theory of gravitation

The exact Bianchi type-VI₀ stiff-fluid cosmological model is obtained in the Nordtvedt-Barker general scalar-tensor theory of gravitation. Some properties of the model are discussed.     

Bianchi type-V radiating model in self-creation cosmology

The spatially-homogeneous and anisotropic cosmological model in self-creation theory of gravitation proposed by Barber, is obtained in the presence of perfect fluid with disordered radiation and the metric is of Bianchi type-V. Some physical properties of the model are discussed.     

Linear and nonlinear oscillations of simple stellar models

A general property for the stability of the one zone model is derived in the case of linear nonadiabatic radial oscillations. The problem of the nonlinear adiabatic radial oscillations of the homogeneous model with a slow rotational velocity is discussed.     

Magnetized cosmological model in Lyra manifold

A spatially-homogeneous and anisotropic magnetized cosmological model in Lyra's manifold is obtained when the source of the gravitational field is a perfect fluid distribution. The magnetic field is due to an electric current produced along thex-axis. The physical behaviour of the model is discussed.     

On the time evolution of quasar luminosity and redshift distribution

The possibility to predict the redshift distribution on the basis of certain assumptions about the time-dependence of quasar luminosity is discussed. It is found that for a certain general class of models that resembles the spinar model for quasars only specific combinations of parameters give rise to acceptable results. Further consequences are discussed.     

The Influence of Waves on Line Formation in Stellar Atmospheres

The influence of acoustic waves on line formation is investigated. The effect of velocity model parameters, e.g. wave number and amplitude, and of the μ-dependence on line formation are discussed by simplified model assumptions. The effect of waves and Gaussian stochastic turbulence is compared.     

Plane symmetric vacuum bianchi type I cosmological model in Brans-Dicke theory

The paper presents an exact solution of the vacuum Brans-Dicke field equations for the metric tensor of a spatially homogeneous and anisotropic cosmological model. The Kasner metric is shown as a special case. Some physical properties of the model are discussed.