Coherent lidars based on intracavity heterodyning of echo signals

The development and technical realization of the method of laser sounding of the atmosphere based on the effects of mixing of reference and external fields of scattering inside a laser cavity are presented. An approximate theory of the method was developed on the basis of the investigations using the model of a three-mirror laser. The nonlinear effect of a wideband laser on frequency-dependent external influences of the atmosphere was investigated. The field measurements of gaseous composition of the atmosphere were performed on the basis of a given method of coherent reception using a tunable CO2 laser

Rapid assessment of nonlinear optical propagation effects in dielectrics

Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrödinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process

Теоретические закономерности и институциональные особенности финансирования искусства

The authors have analyzed organizations of the performing arts sector, one of the classic key benefits in the economy. The empirical research has been based on the economic pattern of “cost disease”. A unique statistical database has been compiled on the basis of the information database of the Federal State Statistics Service and the Ministry of culture of the Russian Federation. The research presents the Baumol’s indices calculations updated in 2001–2015. There have been confirmed such symptoms of Baumol’s cost disease as: labor productivity in cultural organizations lagging behind the average regional rate, super-inflationary growth for ticket prices in theaters, and catch-up wage growth in the theater in relation to the average wage level in the region. The author’s approach to the analysis of the Baumol’s cost disease is a modification of the overall Baumol index as a replacement for the income deficit indicator for the share of expenses covered by budget funds. New results have been obtained for estimating the income deficit and the share of expenditures covered by public funding by using the panel data model and quantile regression. The practical value of this research is the systematization of budgetary and extra-budgetary support for cultural organizations. New institutions of financial support such as the institute of participatory budgeting and the institution of individual budget allocations have been suggested to create favorable environment for the development of cultural organizationsАвторы анализируют функционирование учреждений сферы культуры и искусства, которая является одним из классических примеров опекаемых благ в экономике. Эмпирическое исследование опирается на экономическую закономерность «болезнь цен». Составлена уникальная статистическая база данных на основе информации Росстата и информационной базы данных Министерства культуры РФ. В исследовании обновлены расчеты индексов Баумоля за период 2001–2015 гг. Получено подтверждение наличия таких симптомов «болезни Баумоля», как: отстающая от среднерегионального темпа производительность труда в учреждениях культуры, сверхинфляционный рост цен на билеты в театрах, догоняющий рост заработных плат в театре по отношению к среднему уровню заработных плат в регионе. Авторским подходом к анализу «болезни цен» Баумоля можно считать модификацию общего индекса Баумоля в виде замены показателя дефицита дохода на долю расходов, покрываемых за счет бюджетных средств. Получены новые результаты оценки дефицита дохода и доли расходов, покрываемых за счет государственного финансирования, с использованием модели панельных данных и квантильной регрессии. Практическая ценность данного исследования состоит в систематизации механизмов бюджетной и внебюджетной поддержки учреждений искусств. В качестве основы для создания благоприятной среды развития организаций культуры предложены такие новые институты финансовой поддержки, как институт партисипативного бюджетирования и институт индивидуальных бюджетных назначений

Island model with genetic algorithm for solution of crystal structure from X-ray powder diffraction data

In this paper, we consider the problem of the study of polycrystalline substances: restoration of a substance atomic structure by full-profile analysis of powder diffraction data. This task is specific since it is not necessary to find very good solutions on average, but it is necessary to find the best one at least sometimes. To solve this problem, it is proposed to use an evolutionary algorithm based on the cooperative island model. The article describes the main stages and features of the algorithm and notes the qualitative advantages of this model in comparison with other methods (including evolutionary). The description of innovations proposed and the results of computational experiments are given. Conclusions from the experimental results are given, and further prospects for improving the efficiency of this method were noted

Ion beam irradiation of ABO4 compounds with the fergusonite, monazite, scheelite, and zircon structures

The effects of irradiation on CaWO4, SrWO4, BaWO4, YVO4, LaVO4, YNbO4, and LaNbO4 were investigated on thin crystals using 1.0 MeV Kr ions at 50-1000 K. All of the ABO4 compounds can be amorphized with calculated damage cross sections (σa = 1/Fc0) in the range of ~ 0.30-1.09 × 10-14 cm2 ion-1 at zero Kelvin. Analysis of fluence-temperature data returned critical temperatures for amorphization (Tc) of 311 ± 1, 358 ± 90, 325 ± 19, 415 ± 17, 541 ± 6, 636 ± 26, and 1012 ± 1 K, respectively for the compounds listed above. Compared with previous in situ irradiation of ABO4 orthophosphate samples using 0.8 MeV Kr ions, the Tc values of LaVO4 and YVO4 are higher than those of LaPO4 and YPO4 by 82 K and 124 K, respectively. The Tc values of the three scheelite structures, CaWO4, SrWO4, and BaWO4, indicate that they are the most radiation tolerant compounds under these conditions. The A-B cation anti-site energies, EfAB, determined by DFT range from 2.48 to 10.58 eV and are highly correlated with the A-B cation ionic radius ratio, rA/rB, but are not correlated with Tc across the different structure types, suggesting that the formation and migration energies of Frenkel defects play a more important role in damage recovery in these compounds. We also discuss the role of cation and anion charge/iconicity as determined by DFT. ABO4 compounds with the zircon structure and B = P or V have a distinct advantage over those with B = Si as the damaged regions do not appear to be significantly affected by polymerization of (PO4)3- or (VO4)3- groups which might stabilize the amorphous fraction and ultimately lead to phase separation as observed in zircon (ZrSiO4)

Polycentric binding in complexes of trimethylamine-N-oxide with dihalogens

Dihalogens readily interact with trimethylamine-N-oxide under ambient conditions. Accordingly, herein, stable 1 : 1 adducts were obtained in the case of iodine chloride and iodine bromide. The crystal and molecular structure of the trimethylamine-N-oxide–iodine chloride adduct was solved. Furthermore, the geometry and electronic structure of the trimethylamine-N-oxide–dihalogen complexes were studied computationally. Only molecular ensembles were found in the global minimum for the 1 : 1 stoichiometry. The O⋯X–Y halogen bond is the main factor for the thermodynamic stability of these complexes. Arguments for electrostatic interactions as the driving force for this noncovalent interaction were discussed. Also, the equilibrium structures are additionally stabilised by weak C–H⋯X hydrogen bonds. Consequently, formally monodentate ligands are bound in a polycentric manner

Взаимосвязь цен на нефть и макроэкономических показателей в России

One of the most important external factors affecting the exchange rate of the US dollar to the Russian rouble has been the global oil price. Russia, whose economy is mainly associated with oil production, is one of the world’s largest oil suppliers. Therefore, the slightest fluctuations in oil prices can have a significant effect on its economy. The aim of the article is to study the relationship between macroeconomic parameters and oil prices. The objectives of the study are to identify factors having a long-term positive relationship with oil prices based on a mathematical approach, as well as to propose improvements for Russian macroeconomic indicators. The authors use modern mathematical methods of vector autoregression (VAR-model), the Granger method and the Dickey-Fuller test to study the long-term and shortterm relationships between the relevant time series for the period from 2014 to 2016. On this basis, it was calculated that a 1% increase in GDP leads to a strengthening of the national currency by 1.47%. This fact can be explained by the overall growth of the national economy. The Granger test results for the model show that global oil price (and Russian GDP) has the greatest impact on the exchange rate in the short term. The following actions are proposed for improving macroeconomic indicators: stabilisation of foreign economic policy; diversification of exports (although oil revenues can serve as a tool for improving the quality of Russian economic development and public life in general); development of the Russian ‘Urals’ benchmark and increasing its trading volumes on the world market; transition to rubles for settlements of Russian oil and gas; use of a ruble indicator (ruble barrel) of the ‘Urals’ oil price to support the development of Russia’s financial and economic policy.Одним из важнейших внешних факторов, влияющих на курс доллара к рублю, продолжает оставаться мировая цена на нефть. Россия — один из крупнейших в мире поставщиков «черного золота», ее экономика в основном связана с нефтедобычей. Поэтому малейшие колебания цен на нефть оказывают на нее сильнейшее влияние. Цель работы — изучение взаимосвязи между макроэкономическими параметрами и ценами на нефть. Задачи исследования: выявление факторов, имеющих долгосрочную положительную связь с ценами на нефть на основе математического подхода и подготовка предложений по улучшению макроэкомических индикаторов России. Авторы используют современные математические методы векторной авторегрессии (VAR-модель), метод Грэнджера, тест Дики-Фуллера для исследования долгосрочных и краткосрочных отношений между временными рядами за период c 2014 по 2016 г. Рассчитано, что рост ВВП на 1% приводит к укреплению национальной валюты на 1,47%. Этот факт можно объяснить ростом экономики страны в целом. Результаты теста Грейнджера для модели показывают, что цена на нефть (как и ВВП) оказывает наибольшее влияние на валютный курс в краткосрочной перспективе. Предложены следующие действия по улучшению макроэкономических показателей: стабилизация внешнеэкономической политики; диверсификация экспорта: нефтяные доходы могут превратиться в инструмент повышения качества развития российской экономики и жизни общества в целом; формирование российского бэнчмарка Urals и повышение объемов торгов по нему до мирового уровня; перевод расчетов за российскую нефть и газ в рубли; использование рублевого индикатора (рублевый баррель) цены на нефть марки Urals при формировании финансово-экономической политики России

СПЕКТРОСКОПИЧЕСКАЯ ДИАГНОСТИКА ДВУХИМПУЛЬСНОЙ ЛАЗЕРНОАБЛЯЦИОННОЙ ПЛАЗМЫ В ЖИДКОСТИ ДЛЯ ОПТИМИЗАЦИИ ПРОЦЕССА СИНТЕЗА НАНОЧАСТИЦ

The features of plasma formation in double-pulse laser ablation in liquid have been studied to optimize the process of nanoparticles synthesis. On the basis of spectroscopic plasma diagnostics the spatial structure and the time range of laserinduced plasma emission have been revealed and the composition of its component has been determined. Исследуются особенности плазмообразования при двухимпульсной лазерной абляции в жидкости с целью оптимизации процесса синтеза наночастиц. На основе спектроскопической диагностики выяснена пространственная структура и временной диапазон излучения лазерно-индуцированной плазмы, создаваемой под действием сдвоенных лазерных импульсов в жидкости, и определен ее компонентный состав.