A transverse current rectification in graphene superlattice

A model for energy spectrum of superlattice on the base of graphene placed on the striped dielectric substrate is proposed. A direct current component which appears in that structure perpendicularly to pulling electric field under the influence of elliptically polarized electromagnetic wave was derived. A transverse current density dependence on pulling field magnitude and on magnitude of component of elliptically polarized wave directed along the axis of a superlattice is analyzed.Comment: 12 pages, 6 figure

Acoustic and oceanographic observations and configuration information for the WHOI moorings from the SW06 experiment

This document describes data, sensors, and other useful information pertaining to the moorings that were deployed from the R/V Knorr from July 24th to August 4th, 2006 in support of the SW06 experiment. The SW06 experiment was a large, multi-disciplinary effort performed 100 miles east of the New Jersey coast. A total of 62 acoustic and oceanographic moorings were deployed and recovered. The moorings were deployed in a “T” geometry to create an along-shelf path along the 80 meter isobath and an across-shelf path starting at 600 meters depth and going shoreward to a depth of 60 meters. A cluster of moorings was placed at the intersection of the two paths to create a dense sensor-populated area to measure a 3-dimensional physical oceanography. Environmental moorings were deployed along both along-shelf and across-shelf paths to measure the physical oceanography along those paths. Moorings with acoustic sources were placed at the outer ends of the “T” to propagate various signals along these paths. Five single hydrophone receivers were positioned on the across shelf path and a vertical and horizontal hydrophone array was positioned at the intersection of the “T” to get receptions from all the acoustics assets that were used during SW06.Funding was provided by the Office of Naval Research under Contract No. N00014-04-1014

Self-induced and induced transparencies of two-dimensional and three- dimensional superlattices

The phenomenon of transparency in two-dimensional and three-dimensional superlattices is analyzed on the basis of the Boltzmann equation with a collision term encompassing three distinct scattering mechanisms (elastic, inelastic and electron-electron) in terms of three corresponding distinct relaxation times. On this basis, we show that electron heating in the plane perpendicular to the current direction drastically changes the conditions for the occurrence of self-induced transparency in the superlattice. In particular, it leads to an additional modulation of the current amplitudes excited by an applied biharmonic electric field with harmonic components polarized in orthogonal directions. Furthermore, we show that self-induced transparency and dynamic localization are different phenomena with different physical origins, displaced in time from each other, and, in general, they arise at different electric fields.Comment: to appear in Physical Review

Тестирование модели IRI по данным российских ионосферных станций Ловозеро, Салехард, Диксон, Тунгуска и Якутск

Empirical models are one of effective ways to set and predict a condition of the ionosphere. To estimate an accuracy of such setting it is necessary to test models by means of experimental data. One of most widely used models is IRI (International Reference Ionisphere), however it is insufficiently tested in the region of high latitudes. In the given article results of testing of the model IRI according to vertical sounding on Russian ionosondes, located in subauroral and high-latitude zones in March– April 2016 are presented. Feature of the period is presence of several geomagnetic disturbances. The studied parameter is a critical frequency foF2, the basic analyzed magnitude is the deviation of a model value from experimental one and its relative mean square deviation. Despite increase last years of numbers of ionosondes in a Russian Arctic zone by efforts of AARI, their number is not enough for detailed monitoring. Additionally, it is possible to use receivers of signals of navigation satellites of such systems, as GPS, GLONASS, providing the information about a total electron content (ТЕС). In a number of papers, possibility of use of ТЕС to obtain critical frequencies is shown. In the present paper, confirmation of this possibility is given in subauroral and high-latitude regions. Results are presented for five Russian stations (Lovozero, Salekhard, Dickson, Tunguska,Yakutsk) in comparison with data of reference middle-latitude station Juliustuh. It is shown, that deviations of model values of foF2 from experimental medians in high latitudes are at level of middle-latitude values, relative deviations for instant values of foF2 day by day do not exceed 20–25 %. The ТЕС usage allows decreasing this estimation in 2 times. Values of correlation coefficients between foF2 and ТЕС, defining possibility to use ТЕС for obtaining foF2, lay within 0.6–0.99. The ТЕС usage allows filling absent values of foF2.В данной статье приводятся результаты тестирования модели IRI (International Reference Ionisphere) по данным вертикального зондирования на российских ионозондах, расположенных в арктической зоне, в марте–апреле2016 г. Особенностью периода является наличие нескольких геомагнитных возмущений. Полученные в работе данные подтверждают возможность использования TEC для определения критических частот в арктическом регионе. Результаты исследования приводятся для пяти российских станций (Ловозеро, Салехард, Диксон, Тунгуска, Якутск) в сравнении с данными эталонной среднеширотной станции Юлиусрух. Показано, что отклонения модельных значений foF2 от экспериментальных медиан в высоких широтах находятся на уровне среднеширотных, для мгновенных значений foF2 день ото дня относительные изменения могут составлять до 20–25 %. Использование TEC позволяет в 2 раза уменьшить эту оценку. Значения коэффициентов корреляции между foF2 и TEC, определяющей возможность использования TEC для расчета foF2, лежат в пределах 0,6–0,99

Economic Ideas and Institutional Change: Evidence from Soviet Economic Discourse 1987-1991

In recent years, institutional and evolutionary economists have become increasingly aware that ideas play an important role in economic development. In the current literature, the problem is usually elaborated upon in purely theoretical terms. In the present paper it is argued that ideas are always also shaped by historical and cultural factors. Due to this historical and cultural specificity theoretical research must be supplemented by historical case studies. The paper analyses the shift in ideas that took place in Soviet economic thought between 1987 and 1991. This case study, it is argued, may contribute to our understanding of the links between ideas and institutions. More specifically, it sheds new light on the issue of whether the evolution of economic ideas is pathdependent, so that they change only incrementally, or whether their development takes place in a discontinuous way that can best be compared with revolutions