Study of terahertz spoof surface plasmons on subwavelength gratings with dielectric substance in grooves

Terahertz (THz) plasmonic devises based on periodical corrugated structures are promising for sensing applications in biology and medicine but have not been developed so far because spoof surface plasmons (SSPs) on such structures were studied insufficiently in the THz spectral range. In the paper, the propagation of THz SSPs along one-dimensional subwavelength rectangular plane gratings with a dielectric substance in the grooves was studied and optimal parameters of gratings (period, aspect ratio and groove depth) for sensing of dielectric were found. First grating samples were made and tested using the THz radiation of the Novosibirsk free electron laser.The investigations were supported by the Russian Science Foundation (grant No. 14-50-00080) and Russian Foundation for Basic Research (grant No. 16-32-00678). The Siberian Synchrotron and Terahertz Radiation Center equipment and free electron laser were employed in the experiments

Spectra of cosmic ray electrons and positrons in the Galaxy

A new study of the cosmic ray electron and positron spectra is presented, using an anomalous diffusion model to describe the particles propagation in the Galaxy. The parameters defining the anomalous diffusion have been recently determined from the study of nuclei propagation. The computed electron and positron spectra under assumption that positrons, as well as electrons, are accelerated by a galactic source, are in a good agreement with the measurements. The source spectral index, found from experimental data, in this approach turns out to be equal to 2.95 for electrons and positrons. The predicted positron fraction e⁺/(e⁺+e⁻) in high energy region E≈10² ÷10³ GeV is ~0.06

3D modeling cloth in cad OPTITEX

В статті представлені дослідження в області 3D моделювання одягу. Увагу зосереджено на продукті під назвою OptiTex. Дана програма являється одним із лідерів на ринку САПР одягу. До складу продукту входить багато модулів, які дозволяють ефективно використовувати даний САПР на багатьох етапах виготовлення одягу, в тому числі двомірному моделюванні. Випробувано даний програмний продукт для візуального відтворення народного костюму на віртуальному манекені.The article presents the results of a study in 3D modeling of clothes. It focuses on CAD product Optitex. This program is one of the leaders in CAD clothing. The product includes many modules that can effectively use this CAD in many stages of the manufacture of clothing, including a two-and three dimensional modelling. This program tested for modelling the national costume and embroidery on a virtual model

Magnetooptics in Gold and Silver NanoSizes Low-Dimensional Objects

The spectra of optical absorption and of magnetic circular dichroism (MCD) have been measured in the 350–1150 nm wavelength range for a set of colloidal solutions containing Au and Ag nanoparticles. The average size of Au nanoparticles was 6 nm and having thiolate coatings with different degrees of chirality. (The average size of Ag nanoparticles was 14 nm and having citrate coatings) The form of absorption and MCD spectra suggests the dipole character of interband transitions involving the 5d–6(sp) for Au orbitals and 4d–5(sp) for Ag orbitals. The absence (within the experimental error) of the MCD spectra dependence on the coating type rules out the hypothesis on the orbital nature of the observed magnetism. We argue that the spin polarization plays the dominant role in the magnetism both for Au and Ag nanoparticles. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3534

Stationary and coherent spectroscopy of 167

We have conducted a spectroscopic investigation of 167Er3+ ions in optical waveguides on an optical transition between the hyperfine sublevels of 4I15/2 and 4I9/2 multiplets. Waveguides with diameters ranging from 20 to 100 µm were produced in the crystal by a femtosecond laser using the depressed-cladding approach. The spectroscopy results of 167Er3+ ions inside the waveguides show additional broadening and an overall shifts of the spectra compared to the bulk spectrum of ions. The sign of the observed frequency shift depends on the diameter of the specific waveguide. We have also observed a two-pulse photon echo in several waveguides. The acquired results show the possibility for integrated quantum schemes in rare-earth ions doped crystals

A 800-kV and 32-kJ pulse generator

The characteristics of oil-insulated 8-stage Marx generator aimed at charging water-insulated line of STRAUS-R electron beam accelerator are presented. Two IEPM-100-0.4 capacitors are installed in each stage. Switches in the first three stage are 100-kV gas-filled trigatrons while in other stages – two-electrode trigatrons. Operation delay time is 108±5 ns at electric strength reserve of each switch being equal to ~ 80%. The circuit inductance is ~1.4 µH.Приведены характеристики маслоизолированного восьмикаскадного генератора (ГИН) Аркадьева-Маркса для зарядки до 700 кВ за < 1 мкс водоизолированной линии ускорителя пучка электронов СТРАУС-Р. В каждом каскаде установлено по два конденсатора ИЭПМ-100-0.4. Коммутаторы в первых трех каскадах – газонаполненные тригатроны на 100 кВ, в остальных – двухэлектродные. Время задержки срабатывания 108+-5 нс при запасе электропрочности каждого разрядника ̴ 80%. Индуктивность контура ГИН ̴ 1,4 мнГн.Наведено характеристики маслоізольованого восьмикаскадного генератора (ГІН) Аркадьєва-Маркса для зарядки до 700 кВ за 1 мкс водоізольованої лінії прискорювача пучка електронів СТРАУС-Р. У кожному каскаді встановлено по два конденсатора ІЕПМ-100-0.4. Комутатори в перших трьох каскадах – газонаповнені тригатрони на 100 кВ, в інших – двохелектродні. Час затримки спрацьовування 108+-5 нс при запасі електроміцності кожного розрядника ̴ 80%. Індуктивність контуру ГІН ̴ 1,4 мкГн

Decay of Unstable D-branes with Electric Field

Using the techniques of two dimensional conformal field theory we construct time dependent classical solutions in open string theory describing the decay of an unstable D-brane in the presence of background electric field, and explicitly evaluate the time dependence of the energy momentum tensor and the fundamental string charge density associated with this solution. The final decay product can be interpreted as a combination of stretched fundamental strings and tachyon matter.Comment: 35 pages, LaTe

Elliptic hypergeometry of supersymmetric dualities II. Orthogonal groups, knots, and vortices

We consider Seiberg electric-magnetic dualities for 4d $\mathcal{N}=1$ SYM theories with SO(N) gauge group. For all such known theories we construct superconformal indices (SCIs) in terms of elliptic hypergeometric integrals. Equalities of these indices for dual theories lead both to proven earlier special function identities and new conjectural relations for integrals. In particular, we describe a number of new elliptic beta integrals associated with the s-confining theories with the spinor matter fields. Reductions of some dualities from SP(2N) to SO(2N) or SO(2N+1) gauge groups are described. Interrelation of SCIs and the Witten anomaly is briefly discussed. Possible applications of the elliptic hypergeometric integrals to a two-parameter deformation of 2d conformal field theory and related matrix models are indicated. Connections of the reduced SCIs with the state integrals of the knot theory, generalized AGT duality for (3+3)d theories, and a 2d vortex partition function are described.Comment: Latex, 58 pages; paper shortened, to appear in Commun. Math. Phy

Method for identifying diffraction satellites of surface plasmons in terahertz frequency range

A new method for the identification of diffraction satellites accompanying surface plasmons (SPs) in the terahertz frequency range is proposed and verified. Reliable detection of these satellites allows the accuracy of plasmon spectrometers for the terahertz range to be significantly increased. The idea of the proposed method is based on the fact that a local thin-film coating element applied onto the SP-guiding surface in the absence of diffraction satellites must reduce the SP intensity by the same amount irrespective of the site of application. Experiments performed on the Novosibirsk free-electron laser facility confirmed the efficiency of the proposed method. © 2010 Pleiades Publishing, Ltd