FTIR investigation of molecular mobility in glassy epoxy-amine oligomers with azo-chromophores

Molecular mobility in glassy epoxy-amine oligomer with covalently attached 4-amino-4'-nitroazobenzene NLO chromophore fragments has been studied by conformational probes method. The conformational transitions in the probes (1,2-dichloroethane and chlorocyclohexane) embedded in the oligomer have been studied in the temperature range from -160°C to +20°C. The freezing of conformational transitions has been observed by FTIR at temperature near T f -90°C. This value is correlated with the secondary relaxation transition temperature in the oligomer. The comparison of the activation volumes of the mobile groups in the probes with volumes of mobile groups in the oligomer allows us to conclude that there is the freezing of benzene rings mobility near ß-process temperature. © Published under licence by IOP Publishing Ltd

The effect of chromophores concentration on the nonlinear optical activity of methacrylic copolymers with azochromophores in the side chain

© Published under licence by IOP Publishing Ltd. Quadratic nonlinear-optical characteristics of thin films based on methacrylic copolymers with of chromophore-containing monomers incorporated at various concentrations are measured by Second Harmonic Generation technique. Optimal chromophores content is obtained to be about 17 mol%, rather high values of nonlinear-optical coefficient, d33, up to 60 pm/V, are determined

Peculiar velocities of supernovae Ia in clusters of galaxies

Наблюдения сверхновых Ia позволяют оценить значения космологических параметров при помощи диаграммы Хаббла. В первую очередь такие наблюдения дают значение постоянной Хаббла, которая является одним из основных космологических параметров. Повышение точности измерений данной величины представляет важную задачу для современной космологии, поэтому необходимо учитывать влияние пекулярных скоростей сверхновых на измерение красного смещения, используемое при построении диаграммы Хаббла. Мы изучаем вклад пекулярных скоростей, обусловленных движением родительских галактик в поле тяготения скопления галактик, для космологической выборки сверхновых Pantheon.Observations of supernovae Ia make it possible to estimate the values of cosmological parameters using the Hubble diagram. First of all, such observations give us a value of the Hubble constant, which is one of the most important cosmological parameters. Improving the accuracy of measurements of this parameter is a priority for modern cosmological analysis. Therefore, it is necessary to take into account the influence of the peculiar velocities of supernovae Ia on the measurement of the redshift, which is used in constructing the Hubble diagram. We study the contribution of peculiar velocities due to the motion of host galaxies in the gravitational field of galaxy clusters for a cosmological sample of supernovae Pantheon.Е. А. Б. благодарит Фонд развития теоретической физики и математики «БАЗИС» 20-2-1-34-1. Исследование выполнено при поддержке Междисциплинарной научно-образовательной школы Московского университета «Фундаментальные и прикладные исследования космоса»

Detection of a new “chemical” boundary at comet Halley

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95342/1/grl3208.pd

Photometry and Modeling of Type IIb Supernova 2017gpn

Observations of SN 2017gpn were performed using a CCD photometer of the Zeiss-1000 telescope (SAO RAS). In this work we present the photometry of 20 epochs of those observations. Based on the photometric data, the light curves of SN 2017gpn in B and R filters were obtained. The multicolor light curves were modeled numerically using the one-dimensional radiation hydrodynamical code STELLA. The question that SN 2017gpn lies well outside the host galaxy (NGC 1343) disk was discussed.Были выполнены наблюдения СН 2017gpn с помощью ПЗС-фотометра телескопа Цейсс-1000 (САО РАН) и проведена фотометрия 20 эпох наблюдений. На основе фотометрических данных были построены кривые блеска СН 2017gpn в B- и R-фильтрах. С помощью радиационного гидродинамического кода STELLA было проведено моделирование двухцветной кривой блеска и определены параметры пред-сверхновой звезды. Также мы изучили вопрос исключительного положения СН 2017gpn относительно центра родительской галактики NGC 1343.Работа выполнена при поддержке гранта РНФ 18-12-00522, а также программы развития МГУ «Выдающиеся научные школы МГУ: Физика звезд, релятивистских компактных объектов и галактик»

Redox trends in cyclometalated palladium(II) complexes

© The Royal Society of Chemistry. A series of diverse binuclear and mononuclear cyclometalated palladium(ii) complexes of different structure was investigated by electrochemical techniques combined with density functional theory (DFT) calculations. The studies including cyclic and differential pulse voltammetry, X-ray structure analysis and quantum chemical calculations revealed a regularity of the complexes oxidation potential on the metal-metal distance in the complexes: the larger Pd-Pd distance, the higher oxidation potentials. The reduction potentials feature unusually high negative values while no correlation depending on the structure could be observed. These results are in a good agreement with the electron density distribution in the complexes. Additionally, ESR data obtained for the complexes upon oxidation is reported

Redox trends in cyclometalated palladium(II) complexes

© The Royal Society of Chemistry.A series of diverse binuclear and mononuclear cyclometalated palladium(ii) complexes of different structure was investigated by electrochemical techniques combined with density functional theory (DFT) calculations. The studies including cyclic and differential pulse voltammetry, X-ray structure analysis and quantum chemical calculations revealed a regularity of the complexes oxidation potential on the metal-metal distance in the complexes: the larger Pd-Pd distance, the higher oxidation potentials. The reduction potentials feature unusually high negative values while no correlation depending on the structure could be observed. These results are in a good agreement with the electron density distribution in the complexes. Additionally, ESR data obtained for the complexes upon oxidation is reported

Опыт применения отечественной вакцины Гам-Ковид-Вак-М для профилактики COVID-19 у детей

The goal is to evaluate the tolerability and effectiveness of the domestic vector vaccine Gam-Covid-Vak-M in children aged 12—17 years, adherence to vaccination of adolescents and parents to improve work on the prevention of COVID-19. Materials and methods. A retrospective analysis of the medical records of 115 children aged 12—17 years who were vaccinated in 2022 with the Gam-COVID-Vac-M vaccine in two children's polyclinics in St. Petersburg was carried out. Additional information was collected through telephone interviews. A cross-sectional anonymous online survey of adolescents aged 15—17 was also conducted to study awareness of COVID-19 and adherence to vaccination. Results. Only 23.5% of those vaccinated were at risk for severe and complicated COVID-19. Parents showed low adherence to vaccination against COVID-19 — 71.3% vaccinated themselves and 73.1% considered it necessary to protect the child. Only in 14.1% of cases, a teenager aged 15—17 made the decision to be vaccinated. According to 76.9% of adolescents, COVID-19 is a dangerous disease, while 55.6% consider vaccination unnecessary, mainly due to ineffective protection and the possibility of complications. Nevertheless, side effects after the first and second components of Gam-COVID-Vac-M were observed in 24.3% and 24.2%, respectively, which is 4 times less than with foreign vaccines. Systemic and local reactions were observed on days 1—2 after immunization. All manifestations were mild or moderate and resolved within 1—2 days on average. Serious adverse events were not registered. The effectiveness of the vaccine was 97.4%. Conclusion. Preliminary results indicate good tolerance and efficacy of the domestic vaccine Gam-COVID-Vac-M.Цель — оценить переносимость и эффективность отечественной векторной вакцины Гам-Ковид-Вак-М у детей 12—17 лет, приверженность к вакцинации подростков и родителей для совершенствования работы по профилактике COVID-19. Материалы и методы. Проведен ретроспективный анализ медицинской документации 115 детей в возрасте 12—17 лет, привитых в 2022 г. вакциной Гам-КОВИД-Вак-М в двух детских поликлиниках Санкт-Петербурга. Дополнительный сбор информации проводился посредством телефонного интервью. Также проведен кросс-секционный анонимный онлайн-опрос подростков 15—17 лет для изучения информированности о COVID-19 и приверженности к вакцинопрофилактике. Результаты. Только 23,5% привившихся относились к группе риска тяжелого и осложнённого течения COVID-19. Родители продемонстрировали приверженность к вакцинации против COVID-19 в 71,3% — привились сами и 73,1% посчитали необходимым защитить ребенка. Лишь в 14,1% случаев подростки 15—17 лет сам приняли решение привиться. По мнению 76,9% подростков СОVID-19 является опасным заболеванием, при этом 55,6% считают вакцинацию неэффективной или вызывающей осложнения. В то же время проведенные нами исследования продемонстрировали невысокий риск побочных реакций после введения первого и второго компонента Гам-КОВИД-Вак-М — в 24,3% и 24,2% соответственно, что оказалось в 4 раза реже по сравнению с зарубежными вакцинами. Системные и местные реакции наблюдались в 1–2-й день после иммунизации. Все проявления были легкими или умеренными и разрешались в среднем за 1–2 дня. Серьезных нежелательных явлений не зарегистрировано. Эффективность вакцины составила 97,4%. Заключение. Предварительные результаты свидетельствуют о хорошей переносимости и эффективности отечественной вакцины Гам-КОВИД-Вак-М

ECRH power deposition from a quasi-optical point of view

A quasi-optical description of the propagation and damping of the slowly varying wave amplitude across an arbitrary electron cyclotron wave beam is presented. This model goes well beyond those implemented in existing beam tracing codes, which typically require the spatial inhomogeneity across the wave beam to be small. The present model allows an accurate description of the wave beam evolution in the region of electron cyclotron power deposition, where the latter condition is quite generally broken. The additional physical effects from spatial inhomogeneity and dispersion included in the quasi-optical model are discussed in relation to their consequences for the power deposition profile. Quite generally, a broader power deposition profile is obtained in the quasi-optical calculations. The importance of these effects is analysed in a number of scans varying the injection geometry for typical conditions in both the ITER and the TEXTOR tokamak. Optimization of the power deposition profile towards a minimal width is found to require a focused wave beam with a waist of typically 2 cm width localized near the electron cyclotron resonance region. Calculations are also presented for beams injected from the ITER Upper Port electron cyclotron resonance heating (ECRH) launcher as it is currently being designed. These show that the additional power deposition profile broadening from quasi-optical effects may result in a drop in the predicted efficiency for neoclassical tearing mode or sawtooth control by up to a factor of 2