首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 687 毫秒
1.
This investigation indicates an ambiguity in interpreting the results of applying the apparatus of the correlation gamma function [(r) and *(r)] to analyze the spatial distribution of objects from some sample. The presence of a linear section in the dependences of log() on log(r) and of log(*) on log(r) proves to be insufficient to state that the distribution has fractal properties (self-similarity). It is shown that a change in the geometrical boundaries of the sample may influence the form of the dependences of log() on log(r) and of log(*) on log(r).  相似文献   

2.
By considering the relativistic expression for isothermal NS cores,T·e /2 = constant, we have shown that some of the standard equations of state, when applied to NS cores, correspond to constancy of some adiabatic exponents. It has been shown that the equation of state,P=KE, corresponds to 1 = to 2 = 3 1 +K and the equation of state, dP/dE=K, corresponds to 3 1 +K. The conditions under which different equations of state represent isothermal cores have been obtained: For isothermal NS, the local temperatureT, can be expressed in terms of pressureP, energy densityE, and rest mass density . For example: (a)P =KE :T = constant × (E/); (b)P=KE :T = constant × (P/); (c) dP/dE =K :T K ; (d) = 2 :T = constant × (P/E); and (e) = 3 :T = constant × (P/)1/2. Equation of state corresponding to = 2 is obtained as:P=E/ln(K/E) and the equation corresponding to = 3 comes out as:E=P ln(K/P). Core-envelope models can be developed for these two cases. When core equation corresponding to = 2 or = 3 is used in the core, we can ensure the continuity of dP/dE at the core-envelope boundary, along with the continuity ofP, E, , and . The parameters of isothermal NS cores corresponding to the cases = 2 and = 3, have been obtained. The maximum mass of these NS cores comes out to be 2.7 .  相似文献   

3.
Two new equations of state obtained for matter constituting isothermal neutron star core by using isentropic nature of matter for the equalities =2 and =3 (where 's are usual adiabatic exponents) have been utilised to discuss the internal temperature of core. The temperature of matter has been obtained asT=T a(P+E)/. Variation ofT/T a(t) with energy density has been discussed for these new equations of state and some standard equations of state for nuclear matter.  相似文献   

4.
General forms of theB-p relation are investigated in both the isothermal and the non-isothermal regions. The magnetic flux dissipation either by ambipolar diffusion or by Ohmic dissipation has been studied. The rates of heating due to the magnetic dissipation processes have been calculated in comparison with the rate of compressional heating.The magnetic field strength is derived as a function of flux/mass ratio, mass, density, and geometry of the isothermal cloud. In the non-isothermal region, the temperature is added to the above-mentioned variables.It has been found that the magnetic flux starts to dissipate via ambipolar diffusion at neutral density ofn>3×109 cm–3. Ambipolar diffusion continues effective until reaching densities ofn>1011 cm–3, where Ohmic dissipation dominates. Under some conditions, the electrons evaporate from the grain surface atn>1013 cm–3, while the ions are still adsorbed on the grain surfce. In this case, the magnetic flux loss returns to be influenced by ambipolar diffusion.The rates of heating by both Ohmic dissipation OD and ambipolar diffusion AD are found to be smaller than the rate of compressional heating C in case of magnetic dissipation. Assuming that the magnetic field is frozen in the medium, then C is smaller than both OD and AD . The above results of heating were found in the non-isothermal region.  相似文献   

5.
The solution of equation of state corresponding to equality =3 gives non-terminating solutions for isothermal neutron star cores. Hence, for this equality, core-envelope models have been developed by taking another equation of state, corresponding to the condition 3, in the envelope. Various static, pulsational, and rotational parameters pertaining to neutron star models are calculated. These models are gravitationally bound and stable for radial perturbations and slow rotations.  相似文献   

6.
J. J. Aly 《Solar physics》1987,111(2):287-296
We consider a simple model in which the coronal magnetic field B is assumed to be potential in the region between the solar surface o and an exterior source-surface 1 of arbitrary shape. We prove that the boundary value problem that determines B from the value B lof its component on 0 along either (orthoradial direction) or (fixed direction) has at most one solution. On the other hand, we show that a solution can exist only if B lsatisfies some solubility conditions.  相似文献   

7.
Résumé La transformation de Lyapunov transforme une équation de Hill en une autre qui occupe la même place dans la classification de Yakubovich.Soit (C) une solution périodique d'un système conservatif à deux degrés de liberté. D'après le principe de moindre action de Maupertuis (C) est l'image d'une géodésique ().Nous montrons que les équations aux variations au voisinage de (C) et de () sont réductibles à deux équations de Hill qui se correspondent par une transformation de Lyapunov.
The Lyapunov transformation of Hill's equation and his dynamic interpretation
The Lyapunov transformation carries Hill's equationÿ+F(t)y=0,F(t+T)=F(t) into another one which belongs to the same class in Yakubovich's classification.Let (C) be a closed trajectory of a Lagrangian conservative system with two degrees of freedom. By the Principle of Least action, we know that (C) is the image of a geodesic () of a certain two-dimensional surface ().We show that the two Hill equations associated with (C) and () are related by a certain Lyapunov transformation.


Paper presented at the 1981 Oberwolfach Conference on Mathematical Methods in Celestial Mechanics.  相似文献   

8.
, , , , ,S , , , S Mg. , . , . , ( , ..). B5 B0; (<1%).  相似文献   

9.
The empirical evidence for a connection between type and relative angular momentum of galaxies is reviewed and some constraints for the theoretical explanation are discussed.
.
  相似文献   

10.
Multiple expansion of the tidal potential   总被引:1,自引:0,他引:1  
The Earth tidal deformation causes an additional gravitational potential. Its effect on the Moon orbital motion has been studied by several authors.In this contribution, we develop this additional potential without specifying the inertial frame chosen.For this purpose, we use the properties of the representation of rotation groups in 3 dimensions space. We finally obtain the interaction potential between the distorted Earth and the Moon which is a necessary preliminary to the study of the evolution of the Earth-Moon system.Nomenclature T.R.O Tide raising object - (, , ) Spherical coordinates of the T.R.O. - (J, E ) Earth spin axis orientation. E is the longitude of the ascending node of Earth's equator on thexy-plane - (a ,I ,e , , ,M ) Elliptics elements of the T.R.O  相似文献   

11.
12.
13.
Conditions are found which are satisfied by the coefficients of the expression being a second integral of the motion of an autonomous dynamical system with two degrees of freedom. The coefficientsA, B. , ,E are differentiable functions of the cartesian position coordinatesx, y. The velocity components are denoted by . It is shown that must be constant andB must be of the formB =f(x+y) +g(x-y) wheref, g are arbitrary.Given andB one can always find the remaining coefficientsA, E and also the corresponding potential and second integral. Depending on the specifica case at hand a certain number of arbitrary constants (or arbitrary functions) enter into the potential and the second integral. To each potential (which may be of the separable or nonseparable type in the coordinatesx andy)there corresponds one integral of the above form.  相似文献   

14.
The general conception of the critical inclinations and eccentricities for theN-planet problem is introduced. The connection of this conception with the existence and stability of particular solutions is established. In the restricted circular problem of three bodies the existence of the critical inclinations is proved for any values of the ratio of semiaxes . The asymptotic behaviour of the critical inclinations as 1 is investigated.
. . . 1.
  相似文献   

15.
2800 Mgii (. 1). (N +/N 11000) , , (N +/N 110). , . —, , . — . : ; 0.002 1 , 0.1 ; () 100 –3; ; ; , 10 ; 10–4 1 . 2800 Mgii .  相似文献   

16.
. , , . , t>1010 ( z<105) .
In this paper we continue the work of Weymann, investigating the causes of distortion of the spectrum of the residual radiation from the Planck curve. We discuss the distortion to the spectrum, resulting from recombination of primeval plasma.We then derive an analytic expression for the distortion to the equilibrium spectrum due to Compton scattering by hot electrons. On the basis of the observational data we conclude that a period of the existence of neutral hydrogen is inescapable in the hot model of the universe. It is concluded that any injection of energy att>1010 sec (red shiftz<105) give the distortions of the equilibrium spectrum.
  相似文献   

17.
18.
A critical study relating to the enhancement factor of nuclear reaction rates in the carbon-oxygen plasma is made. Plots are given of the various dimensionless parameters in the temperature-density plane after the recent analysis of Itohet al. (1977). The enhancement factor of thermonuclear reaction rates critically depends on 3/. The enhancement factors also have been calculated here for the carbon-oxygen plasma studied by Iben (1978).  相似文献   

19.
20.
Lee  Jeongwoo  Chae  J.-C.  Yun  H. S.  Zirin  H. 《Solar physics》1997,171(2):269-282
We report new properties of solar magnetic fields in a quiet region as found from their magnetic power spectra. The power spectra of network and intranetwork fields (non-network fields) are separately calculated from a Big Bear magnetogram obtained with moderately high spatial resolution of 1.5 arc sec and a high sensitivity reaching 2 Mx cm-2. The effect of seeing on the power spectrum has been corrected using Fried's (1966) Modulation Transfer Function with the seeing parameter determined in our previous analysis of the magnetogram. As a result, it is found that the two-dimensional power spectra of network and non-network fields appear in a form: ( 1) -1 and ( 1) -3.5. Here 0 0.47 Mm-1 for network fields and 0 0.69 Mm-1 for non-network fields, the latter of which corresponds to the size of mesogranulation; 1 3.0 Mm-1 for both, which is about the size of a large granule. The network field spectrum below 0 appears nearly flat, whereas that of non-network fields instead decreases towards lower wave numbers as ( ) 1.3. The turnover behavior of magnetic field spectra around 1 coincides with that found for the velocity power spectrum, which may justify the kinetic approach taken in previous theoretical studies of the solar magnetic power spectra.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号