D3+D6 solution and D4+D6 solution

We make the supergravity solutions describing the branes (D3 branes and D4 branes) localized within the D6 branes in the near core region of D6 brane. From the D=11 solutions (M3 branes and M4 branes with the Z_N identifications in the transverse space) we obtain the D=10 supergravity solutions of D3 branes localized within D6 branes and D4 branes localized within D6 branes by reducing the dimension down to D=10 along a circular direction of S³ part of the transverse space. M3 brane solution leads to D=10 background representing D3 branes localized on D6 branes in the region close to the D6 branes core. M4 branes lead to the D4 branes localized on D6 branes in the region close to the D6 brane core.     

2D gravity+1D matter

We consider a formulation of nonperturbative two-dimensional quantum gravity coupled to a single bosonic field (d=1 matter). Starting from a matrix realization of the discretized model, we express the continuum theory as a double scaling limit in which the 2D cosmological constant g tends towards a critical value g_c, and the string coupling 1/N→0, with the scaling parameter ∝1n (g-g_c)/(g-g_c)N held fixed. We find that in this formulation logarithmic corrections already present at tree level persist to all higher genus, suggesting a behavior different from the previously considered cases of d<1 matter.     

Critical conditions for 1D, 2D and 3D magnetic-bipolaron formation

Il Nuovo Cimento D - Interaction of two magnetic polarons formed either by single carriers or by excitons is considered in bulk crystal, quantum well and quantum wire. It is shown that the magnetic...     

Comparison of 1D, 2D and 3D quench onset simulations

Measured and simulated minimum quench energies (MQE) for short samples are doubtful when estimating disturbance tolerance of an impregnated superconducting magnet. If measurements are performed at liquid cryogen, the cooling provided by the cryogen causes MQE to be high. At a conduction-cooled system, the transverse heat conduction is neglected causing low MQE. Even though these conditions can be artificially brought closer to the ones in an impregnated magnet, it is difficult to estimate by short-sample measurement the MQE of a superconducting coil. These similar difficulties are present at simulations. On the other hand, 1D and 2D measurements and simulations can be used, e.g., to compare wires or consider effect of insulation layer thickness, but according to the results only in a rough quantitative way. In this paper, we compare MQE and normal zone propagation velocity simulations of an MgB₂ wire with 1D, 2D and 3D finite element method models to focus on the different results given by the models employing different dimensions.     

6D microstate geometries from 10D structures

We use the formalism of Generalised Geometry to characterise in general the supersymmetric backgrounds in type II supergravity that have a null Killing vector. We then specify this analysis to configurations that preserve the same supersymmetries as the D1–D5–P system compactified on a four-manifold. We give a set of equations on the forms defining the supergravity background that are equivalent to the supersymmetry constraints and the equations of motion. This study is motivated by the search of new microstate geometries for the D1–D5–P black hole. As an example, we rewrite the linearised three-charge solution of arXiv:hep-th/0311092 in our formalism and show how to extend it to a non-linear, regular and asymptotically flat configuration.     

Thick brane in 7D and 8D spacetimes

We consider a thick brane model using two interacting scalar fields in 7D and 8D gravity. Using a special choice of potential energy, we obtain numerically regular asymptotically flat vacuum solutions. The possibility of obtaining the similar solutions for an arbitrary number of extra spatial dimensions is being estimated.     

In memory of professor D. D. Ivanenko

In memory of professor D. D. Ivanenko     

Mobility-aware coded caching in D2D communication networks

In this paper, we consider a cache-enable device-to-device (D2D) communication network with user mobility and design a mobility-aware coded caching scheme to exploit multicasting opportunities for reducing network traffic. In addition to the static cache memory that can be used to reap coded caching gains, we assign a dynamic cache memory to mobile users such that users who never meet can still exchange contents via relaying. We consider content exchange as an information flow among dynamic cache memories of mobile users and leverage network coding to reduce network traffic. Specifically, we transfer our storage and broadcast problem into a network coding problem. By solving the formulated network coding problem, we obtain a dynamic content replacement and broadcast strategy. Numerical results verify that our algorithm significantly outperforms the random and greedy algorithms in terms of the amount of broadcasting data, and the standard Ford–Fulkerson algorithm in terms of the successful decoding ratio.     

Magnetic fields in 2D and 3D sphere

In this note we study the Landau–Hall problem in the 2D and 3D unit sphere, that is, the motion of a charged particle in the presence of a static magnetic field. The magnetic flow is completely determined for any Riemannian surface of constant Gauss curvature, in particular, the unit 2D sphere. For the 3D case we consider Killing magnetic fields on the unit sphere, and we show that the magnetic flowlines are helices with the given Killing vector field as its axis.     

Fluorescence ratio of the two D sodium lines in flames for D1 and D2 excitation

The ratio of the fluorescence intensities from the two lines of the yellow sodium doublet has been investigated in several hydrogen-based and acetylene-based flames and with various types of lasers as excitation sources. The systematic deviation from 2 for the ratio D₂/D₁ when either D₁ or D₂ are used as exciting transitions can be simply explained by the relative difference in the values of the collisional mixing constants between the excited P-levels and the collisional quenching constants transferring atoms from both P-levels to the ground S-level. Results obtained in flames characterized by different values of the quantum efficiency follow the behavior predicted by the fluorescence expressions obtained by a simple, steady-state theoretical approach.     

Intersubband electron interaction in 1D–2D junctions

It is shown that the electron transport through junctions between one-and a two-dimensional systems and through quantum point contacts is considerably affected by the interaction of electrons belonging to different subbands. The interaction mechanism is related to Friedel oscillations, which are produced by the electrons of the closed subbands even in smooth transitions. Because of the interaction with these oscillations, electrons of the open subbands experience a backscattering. The electron reflection coefficient has a sharp peak at the energy equal to the Fermi energy and may reach a value of about 0.1. This result allows one to explain a number of available experimental facts.     

5D geometrical property and 4D property of matter

It is shown that physical quantities in the 4D world such as density and pressure, and an equation of state for a gravitating spherically symmetric fluid, are given by the geometrical property of the fifth dimension of a spherically symmetric line-element in Wesson's 5D theory of gravity.     

2D and 3D SIMS investigations on sintered steels

Powder metallurgy (PM) is a well-established method for manufacturing ferrous precision parts. Sintering is one of the important production steps and can be strongly enhanced (activated) by formation of a liquid phase during the sintering process. The liquid phase can be reached by the addition of alloying elements (e.g., copper) or sintering activators (e.g., phosphorus) and is formed by melting of eutectic phase mixtures or by incipient melting. The main investigations presented in this work are done by secondary ion mass spectrometry (SIMS): 2D and 3D elemental distribution. Additionally, impact energy and hardness measurements were performed in order to study the influence of phosphorus on mechanical properties. The concentration of P in different samples was varied between 0 and 1 weight percent (wt.%), the carbon content was consistently 0.5 wt.%. Nominal specimens were sintered at 1120 and 1250 °C in protective atmosphere of flowing nitrogen to determine the influence of sintering temperature.     

黄花远志黄花皂甙D的二维核磁共振谱研究

用一维、二维波谱技术研究了从中药黄花远志根中分离出一种含六个糖的三萜皂甙,黄花皂甙D,确定了皂甙的双糖链结构以及甙元与糖基、糖基与糖基间的连接位置,并对其一维谱进行了归属.