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61.
Roman Tomaschitz 《Astrophysics and Space Science》2000,271(2):181-203
A pre-relativistic cosmological approach to electromagnetism and gravitation is explored that leads to a cosmic time variation
of the fundamental constants. Space itself is supposed to have physical substance, which manifests by its permeability. The
scale factors of the permeability tensor induce a time variation of the fundamental constants. Atomic radii, periods, and
energy levels scale in cosmic time, which results in dispersionless redshifts without invoking a space expansion. Hubble constant
and deceleration parameter are reviewed in this context. The time variation of the gravitational constant at the present epoch
can be expressed in terms of these quantities. This provides a completely new way to restrain the deceleration parameter from
laboratory bounds on the time variation of the gravitational constant. This variation also affects the redshift dependence
of angular diameters and the surface brightness, and we study in some detail the redshift scaling of the linear sizes of radio
sources. The effect of the varying constants on source counts is discussed, and an estimate on the curvature radius of the
hyperbolic3-space is inferred from the peak in the quasar distribution. The background radiation in this dispersionless, permeable
space-time stays perfectly Planckian. Cosmic time is discussed in terms of atomic and gravitational clocks, as well as cosmological
age dating, in particular how the age of the Universe relates to the age of the Galaxy in a permeable space-time.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
62.
63.
The synchronization between the orbital motion and axial rotation of the two component stars of a binary system is reviewed.
Some previous published papers are mentioned and the general conclusion is outlined: If we shall use a rotating coordinate
system synchronous with one of the two stellar axial rotations, it is not possible to obtain a Jacobi integral and the Roche
geometry cannot be further analyzed. In addition, a theoretical approach is summarized in order to use the axial rotations
of the two component stars, even if the constants of the stellar structure (k2)1, (k2)2must be taken into consideration. So it is found that if the stellar angular velocities are higher than the corresponding
Keplerian angular velocity (ωi≫ ωk, i=
), the problem of the rotational effect could be of practical consideration. Finally, a theoretical relationship between the
two constants (k2)1and (k2)2of the stellar structure is established. 相似文献
64.
Roman V. Baluyev Konstantin V. Kholshevnikov 《Celestial Mechanics and Dynamical Astronomy》2005,91(3-4):287-300
In the paper by Kholshevnikov and Vassilie, 1999, (see also references therein) the problem of finding critical points of
the distance function between two confocal Keplerian elliptic orbits (hence finding the distance between them in the sense
of set theory) is reduced to the determination of all real roots of a trigonometric polynomial of degree eight. In non-degenerate
cases a polynomial of lower degree with such properties does not exist. Here we extend the results to all possible cases of
ordered pairs of orbits in the Two–Body–Problem. There are nine main cases corresponding to three main types of orbits: ellipse,
hyperbola, and parabola. Note that the ellipse–hyperbola and hyperbola–ellipse cases are not equivalent as we exclude the
variable marking the position on the second curve. For our purposes rectilinear trajectories can be treated as particular
(not limiting) cases of elliptic or hyperbolic orbits. 相似文献
65.
Some 15% of solar flares having a soft X-ray flux above GOES class C5 are reported to lack coherent radio emission in the
100 – 4000 MHz range (type I – V and decimetric emissions). A detailed study of 29 such events reveals that 22 (76%) of them
occurred at a radial distance of more than 800″ from the disk center, indicating that radio waves from the limb may be completely
absorbed in some flares. The remaining seven events have statistically significant trends to be weak in GOES class and to
have a softer non-thermal X-ray spectrum. All of the non-limb flares that were radio-quiet above 100 MHz were accompanied
by metric type III emission below 100 MHz. Out of 201 hard X-ray flares, there was no flare except near the limb (R>800″) without coherent radio emission in the entire meter and decimeter range. We suggest that flares above GOES class C5
generally emit coherent radio waves when observed radially above the source. 相似文献
66.
Anthropogenic sea-level rise (SLR) causes considerable risks. Designing a sound SLR risk-management strategy requires careful consideration of decision-relevant uncertainties such as the reasonable upper bound of future SLR. The recent Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment reported a likely upper SLR bound in the year 2100 near 0.6 m (meter). More recent studies considering semi-empirical modeling approaches and kinematic constraints on glacial melting suggest a reasonable 2100 SLR upper bound of approximately 2 m. These recent studies have broken important new ground, but they largely neglect uncertainties surrounding thermal expansion (thermosteric SLR) and/or observational constraints on ocean heat uptake. Here we quantify the effects of key parametric uncertainties and observational constraints on thermosteric SLR projections using an Earth system model with a dynamic three-dimensional ocean, which provides a mechanistic representation of deep ocean processes and heat uptake. Considering these effects nearly doubles the contribution of thermosteric SLR compared to previous estimates and increases the reasonable upper bound of 2100 SLR projections by 0.25 m. As an illustrative example of the effect of overconfidence, we show how neglecting thermosteric uncertainty in projections of the SLR upper bound can considerably bias risk analysis and hence the design of adaptation strategies. For conditions close to the Port of Los Angeles, the 0.25 m increase in the reasonable upper bound can result in a flooding-risk increase by roughly three orders of magnitude. Results provide evidence that relatively minor underestimation of the upper bound of projected SLR can lead to major downward biases of future flooding risks. 相似文献
67.
Basing on the Asymmetric Continuum Theory, we develop the thermodynamics including fragmentation spin fracture processes; applications for the earthquake source processes are considered. The fracture band model is used to describe a dislocation and disclination superlattice. The Gibbs free energy of defect formation is specified. A dynamic spin fracture criterion was formulated. Consequently, a dynamic model of rock fracture employing dislocations, disclinations, and cracks was constructed to describe slip and fragmentation fracture processes in the earthquake sources. 相似文献
68.
Akhmetkal MEDEU Maulken ASKAROVA Roman PLOKHIKH Irina SKORINTSEVA Aruzhan BEKKULIYEVA 《资源与生态学报(英文版)》2015,6(2):114-118
The Great Silk Road is a trade route linking the East and West which gave impetus to the development of ancient society, and Kazakhstan is the heart of the trade route. At the initial stage, intensive transaction of goods took place between the West and East through The Great Silk Road. This paper reviewed the history of development of the Silk Road and suggested that today to construct the "New Silk Road", Kazakhstan should face many issues, and take many steps to become a Eurasian hub through taking full of advantages. Above all, developing mechanisms of integration and sustainable development is our urgent need. 相似文献
69.
Seasonal meteorological events of high wind energy are important in the export of organic carbon from Biscayne Bay, Florida, by altering circulation and tidal flushing patterns coincident with increased resuspension. The accumulation of detrital organic carbon in the bay during productive summer months with light south-east breezes is reversed by the onset of the winter season and associated weekly cold fronts with sustained 15 knot northerly winds. The reversal of Biscayne Bay circulation patterns and increased discharge at Caesar's Creek result in an outwelling of dissolved organic carbon and particulate organic carbon. Southward advection at the seaward extremes of exchange channels prevents reintroduction of exported organic carbon by tidal currents. 相似文献
70.
Roman U. Sexl Hannelore Sexl Hanns Stremnitzer Donald G. Burkhard 《Earth, Moon, and Planets》1971,3(2):189-213
A theory of the directional characteristics of the lunar infrared radiation measured by Saari and Shorthill has been derived. This theory is in excellent agreement with experiment at all angles of observation and at all phase angles. The radiation law used to describe the angular dependence of the infrared radiation emitted by a flat element of the lunar surface is 0.85 cos + 0.22 cos2, where is the angle between the surface normal and the direction of observation. This radiation law is subsequently modified by taking into account lunar surface roughness. We assume a surface covered in part with spherical craters of various depth to diameter ratios as a model for the lunar soil. Re-radiation within the craters has been accounted for. Extensive use is made of group theoretical and invariant tensor methods which enable us to show that most of the details of the radiation pattern do not depend on the detailed nature of the surface features assumed, but only on the average surface slope. A best fit to the Saari-Shorthill data has been obtained by assuming 50% of the lunar surface to be covered with craters with a depth to diameter ratio of 1:3, while the remainder of the surface is essentially flat. The mean deviation between theory and experiment is 4K.This work has been supported by the National Aeronautics and Space Administration under Contracts No. NAS8-20 385 and NAS8-25 585, Marshall Space Flight Center, Alabama.Receipt delayed due to postal strike in Great Britain. 相似文献