Effect of Interactions on the Admittance of Ballistic Wires

A self-consistent theory of the admittance of a perfect ballistic, locally charge neutral wire is proposed. Compared to a non-interacting theory, screening effects drastically change the frequency behavior of the conductance. In the single-channel case the frequency dependence of the admittance is monotonic, while for two or more channels collective interchannel excitations lead to resonant structures in the admittance. The imaginary part of the admittance is typically positive, but can become negative near resonances.Comment: Presentation considerably modified; the results are unchanged. 4 pages, 2 figures .eps-format include

Lattice WW algebras and quantum groups

We represent Feigin's construction [22] of lattice W algebras and give some simple results: lattice Virasoro and $W_3$ algebras. For simplest case $g=sl(2)$ we introduce whole $U_q(sl(2))$ quantum group on this lattice. We find simplest two-dimensional module as well as exchange relations and define lattice Virasoro algebra as algebra of invariants of $U_q(sl(2))$. Another generalization is connected with lattice integrals of motion as the invariants of quantum affine group $U_q(\hat{n}_{+})$. We show that Volkov's scheme leads to the system of difference equations for the function from non-commutative variables.Comment: 13 pages, misprints have been correcte

Long-range odd triplet superconductivity in SF structures with Neel walls

We consider a multidomain superconductor/ferromagnet (SF) structure with an in-plane magnetization, assuming that the neighboring domains are separated by the Neel domain walls. We show that an odd triplet long-range component arises in the domain walls and spreads into domains over a long distance of the order \xi_T = \sqrt{D/2\pi T} (in the dirty limit). The density of states variation in the domains due to this component changes over distances of the order \xi_T and turns to zero in the middle of domains if the magnetization rotates in the same direction in all domain walls.Comment: 9 pages (including 3 EPS figures), REVTeX

Conductance of a junction between a normal metal and a Berezinskii superconductor

The conductance of a junction between a normal metal and a superconductor having the symmetry proposed by Berezinskii is studied theoretically. The main feature of this symmetry is the odd frequency dependence of the anomalous Green function, which makes possible the s-wave triplet superconducting state (the Berezinskii superconductor). The Andreev reflection (which links positive and negative energies) is sensitive to the energetic symmetry; as a result, the conductance of the junction involving the Berezinskii superconductor is qualitatively different from the case of a conventional superconductor. Experimentally, the obtained results can be employed to test the possibility of the Berezinskii superconductivity proposed for Na$_x$CoO$_2$ and to identify the odd-omega component predicted for superconductor-ferromagnet junctions.Comment: 5 pages (including 3 EPS figures

The superfield quantisation of a superparticle action with an extended line element

A massive superparticle action based on the generalised line element in N = 1 global superspace is quantised canonically. A previous method of quantising this action, based on a Fock space analysis, showed that states existed in three supersymmetric multiplets, each of a different mass. The quantisation procedure presented uses the single first class constraint as an operator condition on a general N = 1 superwavefunction. The constraint produces coupled equations of motion for the component wavefunctions. Transformations of the component wavefunctions are derived that decouple the equations of motion and partition the resulting wavefunctions into three separate supermultiplets. Unlike previous quantisations of superparticle actions in N = 1 global superspace, the spinor wavefunctions satisfy the Dirac equation and the vector wavefunctions satisfy the Proca equation. The off-shell closure of the commutators of the supersymmetry transformations, that include mass parameters, are derived by the introduction of auxiliary wavefunctions. To avoid the ghosts arising in a previous Fock space quantisation an alternative conjugation is used in the definition of the current, based on a Krein space approach

Зміни окисно-відновних реакцій у тканині легень за умов опікової травми та при її корекції із застосуванням ліофілізованого ксенодермоімплантата й екзогенного препарату сурфактанту

Oxidative stress in the body of the experimental animals after burn injury arises and develops on the backgroundof activation of free radical oxidation and decrease of antioxidant activity and increase of endotoxemia. The combineduse of surfactant preparation and lyophilized xenographt substrate after skin burns lead to a significant decrease ofendotoxemia, inhibition of lipid peroxidation processes and restoring functional activity of antioxidant protection.После экспериментальной термической травмы в организме подопытных животных на фоне активации процессов свободнорадикального окисления и снижения антиоксидантной активности и нарастания проявлений эндотоксемии возникает и развивается оксидативный стресс. Совместное применениепрепарата сурфактанта и субстрата лиофилизированной ксенокожи после ожогов кожи приводит к существенному снижению проявлений эндотоксемии, угнетению процессов липопероксидации и восстановлению функциональной активности антиоксидантной защиты.Після експериментальної термічної травми в організмі піддослідних тварин на фоні активації процесіввільнорадикального окиснення і зниження антиоксидантної активності та наростання проявів ендотоксеміївиникає і розвивається оксидативний стрес. Поєднане застосування препарату сурфактанту і субстра-ту ліофілізованої ксеношкіри після опіків шкіри призводить до суттєвого зниження проявів ендотоксемії,пригнічення процесів ліпопероксидації та відновлення функціональної активності антиоксидантногозахисту

Steric Effects in Electrolytes: A Modified Poisson-Boltzmann Equation

The adsorption of large ions from solution to a charged surface is investigated theoretically. A generalized Poisson--Boltzmann equation, which takes into account the finite size of the ions is presented. We obtain analytical expressions for the electrostatic potential and ion concentrations at the surface, leading to a modified Grahame equation. At high surface charge densities the ionic concentration saturates to its maximum value. Our results are in agreement with recent experiments.Comment: 4 pages, 2 figure

Ефективність замісної сурфактантної терапії для корекції проявів оксидативного стресу в тканині легень у динаміці після експериментальної термічної травми

Complex structural and metabolic changes in lung tissue after burn injury occur as a result of free radical processes activation under decrease of antioxidant protection enzymes activity and increase of endotoxemia. The correction of thermal trauma by surfactant reduces free radical processes and increases antioxidant enzymes activity in the blood and lung tissue of experimental animals and restores prooxidant-antioxidant balance that consequently causes the decrease of endogenous intoxication intensityВ ткани легких при ожоговой травме происходят сложные структурные и метаболические измененияв результате активации свободнорадикальных процессов на фоне уменьшения активности ферментовантиоксидантной защиты и нарастания проявлений эндотоксемии. Коррекция термической травмыпрепаратом сурфактанта способствует снижению активности свободнорадикальных процессов и повышению активности антиоксидантных ферментов в ткани легких и крови подопытных животных,восстановлению прооксидантно-антиоксидантного равновесия и, как результат, уменьшению в них проявлений эндогенной интоксикации.У тканині легень при опіковій травмі відбуваються складні структурні та метаболічні зміни врезультаті активації вільнорадикальних процесів на тлі зменшення активності ферментів антиоксидант-ного захисту і наростання проявів ендотоксемії. Корекція термічної травми препаратом сурфактантусприяє зниженню активності вільнорадикальних процесів та підвищенню активності антиоксидантнихферментів у тканині легень і крові піддослідних тварин, відновленню прооксидантно-антиоксидантноїрівноваги та, як наслідок, зменшенню в них проявів ендогенної інтоксикації

Quantum Hall effect in a p-type heterojunction with a lateral surface quantum dot superlattice

The quantization of Hall conductance in a p-type heterojunction with lateral surface quantum dot superlattice is investigated. The topological properties of the four-component hole wavefunction are studied both in r- and k-spaces. New method of calculation of the Hall conductance in a 2D hole gas described by the Luttinger Hamiltonian and affected by lateral periodic potential is proposed, based on the investigation of four-component wavefunction singularities in k-space. The deviations from the quantization rules for Hofstadter "butterfly" for electrons are found, and the explanation of this effect is proposed. For the case of strong periodic potential the mixing of magnetic subbands is taken into account, and the exchange of the Chern numbers between magnetic subands is discussed.Comment: 12 pages, 5 figures; reported at the 15th Int. Conf. on High Magnetic Fields in Semicond. Phys. (Oxford, UK, 2002