2,765 research outputs found
Morphological features of river channels and floodplains in the Far East of Russia under various natural conditions
Geographical analysis of river channel processes in rivers located along the meridional transect, running from the Arctic Ocean coast to Tibet and the East China Sea, confirmed that fluvial processes dominate in the formation of morphology and dynamics of river channels and floodplains in all natural zones and under different conditions of channel deformation development. However, even a small disturbance in βclimateβ conditions by other exogenous geomorphological processes changes the morphology and dynamics of channels and floodplains as well as the dynamics of fluvial processes. The effect of zonal factors depends on the size of a given river and is more pronounced in medium and small rivers than the large ones. Furthermore, the effect of zonal factors on the processes of river channels and floodplains depends on specific environmental conditions of the climate zones: the more extreme the manifestation of certain climatic phenomena, the more pronounced they are in the morphology and dynamics of river channels and floodplains
Billiards with polynomial mixing rates
While many dynamical systems of mechanical origin, in particular billiards,
are strongly chaotic -- enjoy exponential mixing, the rates of mixing in many
other models are slow (algebraic, or polynomial). The dynamics in the latter
are intermittent between regular and chaotic, which makes them particularly
interesting in physical studies. However, mathematical methods for the analysis
of systems with slow mixing rates were developed just recently and are still
difficult to apply to realistic models. Here we reduce those methods to a
practical scheme that allows us to obtain a nearly optimal bound on mixing
rates. We demonstrate how the method works by applying it to several classes of
chaotic billiards with slow mixing as well as discuss a few examples where the
method, in its present form, fails.Comment: 39pages, 11 figue
Experimental modelling of lightning interaction phenomena with a free potential conducting objects
Laboratory experiments were conducted to investigate the physical processes of the development of air discharge and its interaction with free potential conducting objects. The space-time development of lightning in gaps was recorded by a motion picture camera and an optoelectronic transducer. The electric field at different points in the gap was measured using a Pockels device both in the leader stage and in the stage of the return stroke. Experimental results of the streamer zone length measurements in the gaps with lengths up to 65 meters are presented. The physical processes occurring during the interaction of positive and negative long sparks with isolated objects were investigated. The striking probability of isolated conducting spheres with different diameters and the dependence of the strike on the location of the gap are investigated
Adatom incorporation and step crossing at the edges of 2D nanoislands
Adatom incorporation into the ``faceted'' steps bordering the 2D nanoislands
is analyzed. The step permeability and incorporation coefficients are derived
for some typical growth situations. It is shown that the step consisting of
equivalent straight segments can be permeable even in the case of fast egde
migration if there exist factors delaying creation of new kinks. The step
consisting of alternating rough and straight segments may be permeable if there
is no adatom transport between neighboring segments through the corner
diffusion.Comment: 3 pages, one figur
The wave function of a gravitating shell
We have calculated a discrete spectrum and found an exact analytical solution
in the form of Meixner polynomials for the wave function of a thin gravitating
shell in the Reissner-Nordstrom geometry. We show that there is no extreme
state in the quantum spectrum of the gravitating shell, as in the case of
extreme black hole.Comment: 7 pages, 1 figur
Beam propagation in a Randomly Inhomogeneous Medium
An integro-differential equation describing the angular distribution of beams
is analyzed for a medium with random inhomogeneities. Beams are trapped because
inhomogeneities give rise to wave localization at random locations and random
times. The expressions obtained for the mean square deviation from the initial
direction of beam propagation generalize the "3/2 law".Comment: 4 page
ΠΡΠΎΠ±Π»Π΅ΠΌΠ° ΠΏΡΠ΅ΠΏΠΎΠ΄Π°Π²Π°Π½ΠΈΡ ΡΡΠ΅Π½ΠΈΡ ΠΎ ΠΏΠΎΠ»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ ΡΠ΅ΠΆΠΈΠΌΠ°Ρ Π² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΌ ΠΎΠ±ΡΠ΅ΡΡΠ²ΠΎΠ·Π½Π°Π½ΠΈΠΈ
Russian education heretofore included so danger component how doctrine about state systems. This doctrine was born in the times of the βcold warβ for anti-soviet propaganda and discrimination of USSR. We think that totalitarianism is not independent state system, because itβs extreme form of autocracy. We must revise totalitarian doctrine and modify our education systemΠ ΠΎΡΡΠΈΠΉΡΠΊΠΎΠ΅ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ Π΄ΠΎ ΡΠΈΡ
ΠΏΠΎΡ ΡΠΎΡ
ΡΠ°Π½ΠΈΠ»ΠΎ Π² ΡΠ²ΠΎΠ΅ΠΌ ΡΠΎΡΡΠ°Π²Π΅ ΡΠ°ΠΊΠΎΠΉ ΠΈΠ΄Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈ Π²ΡΠ΅Π΄Π½ΡΠΉ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½Ρ ΠΊΠ°ΠΊ ΡΡΠ΅Π½ΠΈΠ΅ ΠΎ ΠΏΠΎΠ»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΠΆΠΈΠΌΠ°Ρ
. ΠΡΠΎ ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠ·Π΄Π°Π²Π°Π»ΠΎΡΡ Π½Π° ΠΠ°ΠΏΠ°Π΄Π΅ Π΄Π»Ρ ΠΎΠΊΠ°Π·Π°Π½ΠΈΡ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ Π΄Π°Π²Π»Π΅Π½ΠΈΡ Π½Π° Π‘Π‘Π‘Π Π² Π³ΠΎΠ΄Ρ Β«Ρ
ΠΎΠ»ΠΎΠ΄Π½ΠΎΠΉ Π²ΠΎΠΉΠ½ΡΒ». ΠΡΠ΄Π΅Π»Π΅Π½ΠΈΠ΅ ΡΠΎΡΠ°Π»ΠΈΡΠ°ΡΠΈΠ·ΠΌΠ° Π² ΡΠ°Π½Π³ ΡΠ°ΠΌΠΎΡΡΠΎΡΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ»ΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠ΅ΠΆΠΈΠΌΠ° Π±ΡΠ»ΠΎ ΡΠ΄Π΅Π»Π°Π½ΠΎ ΡΠΏΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎ, Π΄Π»Ρ Π΄ΠΈΡΠΊΡΠ΅Π΄ΠΈΡΠ°ΡΠΈΠΈ ΡΠΎΠ²Π΅ΡΡΠΊΠΎΠ³ΠΎ ΡΡΡΠΎΡ Π² Π³Π»Π°Π·Π°Ρ
ΠΌΠΈΡΠΎΠ²ΠΎΠΉ ΠΎΠ±ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΡΡΠΈ. ΠΠΎΠ½ΡΡΠΈΠ΅ ΡΠΎΡΠ°Π»ΠΈΡΠ°ΡΠΈΠ·ΠΌΠ° Π½Π΅ ΡΠ²Π»ΡΠ΅ΡΡΡ Π½Π°ΡΡΠ½ΠΎΠΉ ΠΊΠ°ΡΠ΅Π³ΠΎΡΠΈΠ΅ΠΉ, Π° ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΠ΅Ρ ΡΠΎΠ±ΠΎΠΉ ΡΠ»Π΅ΠΌΠ΅Π½Ρ Π°Π½ΡΠΈΡΠΎΠ²Π΅ΡΡΠΊΠΎΠΉ ΠΏΡΠΎΠΏΠ°Π³Π°Π½Π΄Ρ. Π‘ΡΠΈΡΠ°Π΅ΠΌ, ΡΡΠΎ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎ ΠΏΠ΅ΡΠ΅ΡΠΌΠΎΡΡΠ΅ΡΡ ΡΡΠ΅Π½ΠΈΠ΅ ΠΎ ΠΏΠΎΠ»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΠΆΠΈΠΌΠ°Ρ
ΠΈ Π²Π½Π΅ΡΡΠΈ ΡΠ΅ΡΡΠ΅Π·Π½ΡΠ΅ ΠΊΠΎΡΡΠ΅ΠΊΡΠΈΠ²Ρ Π² ΡΠΎΡΡΠΈΠΉΡΠΊΠΈΠ΅ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°ΡΠ΅Π»ΡΠ½ΡΠ΅ ΡΡΠ°Π½Π΄Π°ΡΡ
From Discrete Hopping to Continuum Modeling on Vicinal Surfaces with Applications to Si(001) Electromigration
Coarse-grained modeling of dynamics on vicinal surfaces concentrates on the
diffusion of adatoms on terraces with boundary conditions at sharp steps, as
first studied by Burton, Cabrera and Frank (BCF). Recent electromigration
experiments on vicinal Si surfaces suggest the need for more general boundary
conditions in a BCF approach. We study a discrete 1D hopping model that takes
into account asymmetry in the hopping rates in the region around a step and the
finite probability of incorporation into the solid at the step site. By
expanding the continuous concentration field in a Taylor series evaluated at
discrete sites near the step, we relate the kinetic coefficients and
permeability rate in general sharp step models to the physically suggestive
parameters of the hopping models. In particular we find that both the kinetic
coefficients and permeability rate can be negative when diffusion is faster
near the step than on terraces. These ideas are used to provide an
understanding of recent electromigration experiment on Si(001) surfaces where
step bunching is induced by an electric field directed at various angles to the
steps.Comment: 10 pages, 4 figure
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