Formal Approach to Research Units Location

The formal description of the effective location of research units is given here. It is proposed for the examination of different location variations

КОКСО-ВЕРТЕБРАЛЬНЫЙ СИНДРОМ И ЕГО ЗНАЧЕНИЕ ПРИ ЭНДОПРОТЕЗИРОВАНИИ ТАЗОБЕДРЕННОГО СУСТАВА (ОБЗОР ЛИТЕРАТУРЫ)

Lumbosacral spine and hip joints is a complex physiological functions of the co-operation of a large number of anatomical structures. Lesions of the links in the system can mutually afflict each other. Combined pathology of the hip and lumbosacral spine is called hip-spine syndrome, or coxa-vertebral syndrome. Symptoms of the joint and spine are very similar and only a careful examination and clinical examination may find the differences. As the disease progresses the hip increases the restriction of movement, there is a contracture of the limbs in a vicious position, which leads to an increase in tilt of the pelvis, increased lumbar lordosis and to functional shortening of limbs on the affected side. This gives rise to functional impairment, and then strain the joints of his spine and disease - osteochondrosis and scoliosis. After the successful operation of total hip replacement is often progressive clinical lesions of vertebral segment, which is manifested pain and is often offset by the results of arthroplasty as the restoration of movement in the hip joint, and the change in length limb after arthroplasty leads to rupture formed a functional stereotype change in the mobility of the lumbar spine, pelvis regression bias that causes the dynamic compression spinal nerve root. Depending on the duration of the existence, severity and nature of changes in the pelvic girdle is suitable correction of equipment replacement surgery, including, for example, in some cases, deliberate shortening or lengthening the preservation of the lower extremity, offset change, etc.Сочетанная патология тазобедренного сустава и пояснично-крестцового отдела позвоночника именуется «hip-spine syndrome» или коксо-вертебральный синдром. По мере прогрессирования заболевания тазобедренного сустава нарастает ограничение движений, возникает контрактура в порочном положении конечности, что приводит к увеличению наклона таза, усилению поясничного лордоза и к функциональному укорочению конечности на стороне поражения. При этом возникают функциональные нарушения, а затем деформация суставов позвоночника и его заболевания - остеохондрозы и сколиозы. После успешно выполненной операции тотального эндопротезирования тазобедренного сустава нередко прогрессирует клиника поражения позвоночного сегмента, проявляющаяся болевым синдромом и часто нивелирующая результаты артропластики, так как восстановление движений в тазобедренном суставе, изменение длины и опороспособности конечности после артропластики приводит к разрыву сформировавшегося функционального стереотипа, изменению подвижности поясничного отдела позвоночника, регрессу перекоса таза, что вызывает появление динамической компрессии корешков спинномозговых нервов. В зависимости от длительности существования, выраженности и характера изменений со стороны тазового пояса целесообразна коррекция техники операции эндопротезирования, включающая, в определенных случаях целенаправленное сохранение укорочения или удлинения нижней конечности, изменение офсета и т.д

Screw dynamo in a time-dependent pipe flow

The kinematic dynamo problem is investigated for the flow of a conducting fluid in a cylindrical, periodic tube with conducting walls. The methods used are an eigenvalue analysis of the steady regime, and the three-dimensional solution of the time-dependent induction equation. The configuration and parameters considered here are close to those of a dynamo experiment planned in Perm, which will use a torus-shaped channel. We find growth of an initial magnetic field by more than 3 orders of magnitude. Marked field growth can be obtained if the braking time is less than 0.2 s and only one diverter is used in the channel. The structure of the seed field has a strong impact on the field amplification factor. The generation properties can be improved by adding ferromagnetic particles to the fluid in order to increase its relative permeability,but this will not be necessary for the success of the dynamo experiment. For higher magnetic Reynolds numbers, the nontrivial evolution of different magnetic modes limits the value of simple `optimistic' and `pessimistic' estimates.Comment: 10 pages, 12 figure

Построение асимптотического приближения решений краевой задачи для релятивистского конечно-разностного уравнения Шрёдингера с сингулярным осцилляторным квазипотенциалом

Using the asymptotic methods the solution of boundary problem for the relativistic finite-difference Schredinger equation with the singular oscillator quasipotential is studied. For this problem eigenvalues and eigenfunctions are considered. It is shown that they have correct non-relativistic limits.В статье с помощью асимптотических методов исследуются решения краевой задачи для релятивистского конечно-разностного уравнения Шрёдингера с сингулярным осцилляторным квазипотенциалом. Для собственных функций и собственных значений этой задачи получены соответствующие нерелятивистские пределы

A class of Schrodinger operators with decaying oscillatory potentials

We discuss Schr\"odinger operators on a half-line with decaying oscillatory potentials, such as products of an almost periodic function and a decaying function. We provide sufficient conditions for preservation of absolutely continuous spectrum and give bounds on the Hausdorff dimension of the singular part of the spectral measure. We also discuss the analogs for orthogonal polynomials on the real line and unit circle.Comment: 18 page

Measurement of xF3xF_3 and F2F_2 Structure Functions in Low Q2Q^2 Region with the IHEP-JINR Neutrino Detector

The isoscalar structure functions $xF_3$ and $F_2$ are measured as functions of $x$ averaged over all $Q^2$ permissible for the range of 6 to 28 GeV of incident neutrino (anti-neutrino) energy at the IHEP-JINR Neutrino Detector. The QCD analysis of $xF_3$ structure function provides $\Lambda_{\bar{MS}}^{(4)} = (411 \pm 200)$ MeV under the assumption of QCD validity in the region of low $Q^2$. The corresponding value of the strong interaction constant $\alpha_S (M_Z) = 0.123^{+0.010}_{-0.013}$ agrees with the recent result of the CCFR collaboration and with the combined LEP/SLC result.Comment: 11 pages, 1 Postscript figure, LaTeX. Talk given at the 7th International Workshop on Deep Inelastic Scattering and QCD (DIS 99), Zeuthen, Germany, 19-23 Apr 199

Persistence of Anderson localization in Schr\"odinger operators with decaying random potentials

We show persistence of both Anderson and dynamical localization in Schr\"odinger operators with non-positive (attractive) random decaying potential. We consider an Anderson-type Schr\"odinger operator with a non-positive ergodic random potential, and multiply the random potential by a decaying envelope function. If the envelope function decays slower than $|x|^{-2}$ at infinity, we prove that the operator has infinitely many eigenvalues below zero. For envelopes decaying as $|x|^{-\alpha}$ at infinity, we determine the number of bound states below a given energy $E<0$, asymptotically as $\alpha\downarrow 0$. To show that bound states located at the bottom of the spectrum are related to the phenomenon of Anderson localization in the corresponding ergodic model, we prove: (a) these states are exponentially localized with a localization length that is uniform in the decay exponent $\alpha$; (b)~ dynamical localization holds uniformly in $\alpha$

Resonant structure of space-time of early universe

A new fully quantum method describing penetration of packet from internal well outside with its tunneling through the barrier of arbitrary shape used in problems of quantum cosmology, is presented. The method allows to determine amplitudes of wave function, penetrability $T_{\rm bar}$ and reflection $R_{\rm bar}$ relatively the barrier (accuracy of the method: $|T_{\rm bar}+R_{\rm bar}-1| < 1 \cdot 10^{-15}$), coefficient of penetration (i.e. probability of the packet to penetrate from the internal well outside with its tunneling), coefficient of oscillations (describing oscillating behavior of the packet inside the internal well). Using the method, evolution of universe in the closed Friedmann--Robertson--Walker model with quantization in presence of positive cosmological constant, radiation and component of generalize Chaplygin gas is studied. It is established (for the first time): (1) oscillating dependence of the penetrability on localization of start of the packet; (2) presence of resonant values of energy of radiation $E_{\rm rad}$, at which the coefficient of penetration increases strongly. From analysis of these results it follows: (1) necessity to introduce initial condition into both non-stationary, and stationary quantum models; (2) presence of some definite values for the scale factor $a$, where start of expansion of universe is the most probable; (3) during expansion of universe in the initial stage its radius is changed not continuously, but passes consequently through definite discrete values and tends to continuous spectrum in latter time.Comment: 18 pages, 14 figures, 4 table

Quantum Diffusion and Eigenfunction Delocalization in a Random Band Matrix Model

We consider Hermitian and symmetric random band matrices $H$ in $d \geq 1$ dimensions. The matrix elements $H_{xy}$, indexed by $x,y \in \Lambda \subset \Z^d$, are independent, uniformly distributed random variables if \abs{x-y} is less than the band width $W$, and zero otherwise. We prove that the time evolution of a quantum particle subject to the Hamiltonian $H$ is diffusive on time scales $t\ll W^{d/3}$. We also show that the localization length of an arbitrarily large majority of the eigenvectors is larger than a factor $W^{d/6}$ times the band width. All results are uniform in the size \abs{\Lambda} of the matrix.Comment: Minor corrections, Sections 4 and 11 update