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Methods of Hierarchical Control of Water Quality Taking into Account Manipulations of the Center and Countermoves of Enterprises 总被引：2，自引：1，他引：1
Methods of hierarchical control including manipulations of a Center and the countermove of enterprises are considered using as an example a dynamic two-level model of river water quality control in the presence of point pollution sources and in the absence of nonpoint sources. 相似文献
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The influence of the Landau-Pomeranchuk effect on the development of a shower generated by ultrarelativistic particles bombarding the surface of a pulsar is discussed. Because of this effect, the path length of the shower increases while low-energy photon generation is strongly suppressed. In view of this, the mechanism of pair production suggested by Cheng, Ruderman, and Jones for the pulsar magnetosphere, may be essential only for pulsars whose magnetic field intensity at the surface lies in a relatively narrow range of aroundB 1012 G. 相似文献
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V. V. Usov 《Astrophysics and Space Science》1988,140(1):39-47
During the evolution of the neutron star its magnetic field first decays exponentially with the time and then may becomes quasi-stationary. The non-decaying magnetic field of the neutron star is generated by a degenerate electron gas which is in the Landau orbital ferromagnetism (LOFER) state. Possibly, due to the neutron star transition into the LOFER state, magnetic fields remained sufficiently strong in the case of such old magnetic neutron stars as powerful X-ray sources (e.g., Her X-1), millisecond pulsars and the binary pulsar PSR 0655+64. 相似文献
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We have considered the spontaneous Compton scattering of radiation in the magnetic field by both a single ultra-relativistic electron and a system of electrons with the power-law energy distribution. The degree of radiation anisotropy was assumed arbitrary. Parameters of the scattering-generated radiation for the entire range of post-scattering photon energies are given in the paper for all possible scattering modes. 相似文献
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A technique for pore pressure measurement in triaxial tests of clay soils under small strains is considered. The essential
role of the following methodic aspects of the measurements is shown, namely, the effect of temperature on the pore pressure
under measurement, its difference in the central part and on the ends, and the dependence of pore pressure on strain rate. 相似文献
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It is suggested that the outflowing plasma in the jets of active galactic nuclei (AGNs) is inhomogeneous and consists of separate
clouds. These clouds are strongly magnetized and move away from the central engine at relativistic speeds. The clouds interact
with an ambient medium which is assumed to be at rest. In the process of this interaction, particles of the ambient medium
are accelerated to high energies at the cloud front and flow ahead of the front. It is shown that the radiation of the accelerated
particles may be responsible for the X-ray and γ-ray emission from AGN jets. TeV γ-ray emission is generated in the inner
parts of AGN jets where the Lorentz factor of the cloud fronts is Γ0≥ 30, while GeV γ-ray emission emanates from the outer
parts of AGN jets where Γ0 is ∼ 10.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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We present the results of numerical simulations of stationary, spherically outflowing, e ± pair winds, with total luminosities in the range 1034–1042 ergs s?1. In the concrete example described here, the wind injection source is a hot, bare, strange star, predicted to be a powerful source of e ± pairs created by the Coulomb barrier at the quark surface. We find that photons dominate in the emerging emission, and the emerging photon spectrum is rather hard and differs substantially from the thermal spectrum expected from a neutron star with the same luminosity. This might help distinguish the putative bare strange stars from neutron stars. 相似文献
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A detailed theory of high-entropy supermassive oblique rotator is developed on the basis of the results of our previous work on the structure and evolution of supermassive rotating magnetic polytropes. Particular attention is paid to the problem of transformation of rotational energy into observable radiation. It is shown that a rather long duration of the quasi-stationary phase in combination with a considerably high value of magnetic dipole radiationL
md in comparison with that of thermal radiationL
th imposes substantial limitations on the character of the model. This combination is realized in the model of an oblique rotator with a rigid rotation and a poloidal magnetic field. Moreover, the magnetic energy must be comparable, in order of magnitude, with the module of the gravitational energy.The magnitude of the torque acting on the rotator by means of the magnetic field is influenced neither by the external plasma thrown out by the low-frequency radiation pressure, nor by the plasma ejected electrostatically, nor by that flowing out due to rotational instability. For definiteness we assume below that the rotational energy is lost by the rotator in the form of a low-frequency magnetic dipole radiation though many of the conclusions drawn in this paper are also valid for the case when the energy is liberated in some other forms (for example, in magnetohydrodynamic waves).Plasma outflow under rotational instability is considered in detail. This is a pulsating outflow. Near the light cylinder the plasma spreads out and begins to interact intensively with the magnetic dipole radiation. As a result, the particles are accelerated up to relativistic energies. Accelerated electrons radiate by synchrotron mechanism with the radiation maximum in the far infra-red region (Figure 4). Compton scattering of this radiation is in the X-ray and gamma regions. The character of the non-thermal radiation calculated accounts for the essential features of the observable radiation from quasars and active galactic nuclei.A secular variation of the magnetic dipole radiation in the course of evolution of a supermassive oblique rotator (Figure 1) with the account taken of the influence of magnetic dipole losses on the value of the angle between magnetic and rotational axes is discussed in the vacuum approximation substantiated in Section 3. For a wide interval of initial values of this angle the non-thermal (synchrotron and Compton) radiation increases in the course of a quasi-static contraction of the rotator, reaches its maximum at whichL
nthL
th, and then decreases considerably due to rapprochement of the magnetic and rotational axes. Such a behaviour ofL
nth corresponds to the expected secular change of the activity of galactic and quasar nuclei as a certain flaring up, reaching the maximum of their activity and subsequent dying out.Some essential properties of quasars and quasar-like phenomena in galactic and quasar nuclei are explained on the basis of the theory presented. As an illustration, the parameters of a supermassive rotator modelling the source of activity in quasar 3C 273 are calculated (Table I). The estimate of the frequency of occurrence of rotators withL
nth>L
th andL
nthL
th is in a reasonable correspondence with the statistics of active phenomena in the nuclei of galaxies of different morphological types.Observational tests for this theory are suggested. The most important one called upon to ascertain the presence in the nuclei of galaxies and quasars of a supermassive body as a source of their activity is the variability of infra-red radiation near its spectral maximum.Similarity and difference between a supermassive oblique rotator and a pulsar, the model of a quasar nucleus as a cluster of pulsars, an axysymmetric rotator and a low-entropy configuration (disk) as stages of the evolution of an oblique rotator as well as the problems of its genesis and fate are discussed at the end of the paper (Section 9). The main results of the paper are listed in Section 10. 相似文献