Effects of temperature and ammonia flow rate on the chemical vapour deposition growth of nitrogen-doped graphene

We doped graphene in situ during synthesis from methane and ammonia on copper in a low-pressure chemical vapour deposition system, and investigated the effect of the synthesis temperature and ammonia concentration on the growth. Raman and X-ray photoelectron spectroscopy was used to investigate the quality and nitrogen content of the graphene and demonstrated that decreasing the synthesis temperature and increasing the ammonia flow rate results in an increase in the concentration of nitrogen dopants up to ca. 2.1% overall. However, concurrent scanning electron microscopy studies demonstrate that decreasing both the growth temperature from 1000 to 900 1C and increasing the N/C precursor ratio from 1/50 to 1/10 significantly decreased the growth rate by a factor of six overall. Using scanning tunnelling microscopy we show that the nitrogen was incorporated mainly in substitutional configuration, while current imaging tunnelling spectroscopy showed that the effect of the nitrogen on the density of states was visible only over a few atom distances

Региональные последствия пандемии COVID-19 и меры правительства в Венгрии

Received July 8, 2020; accepted August 30, 2020.Дата поступления 8 июля 2020 г.; дата принятия к печати 30 августа 2020 г.Relevance. The new coronavirus pandemic (COVID-19) has brought major changes to everyday life and economy in 2020. The impacts of the pandemic are still difficult to measure and interpret. This paper analyses the key socio-economic factors that shaped the course of the pandemic and its regional effects in Hungary. Research objective. The aim of this paper is to provide a secondary data-based analysis of regional disparities in Hungary as well as the implications of the coronavirus pandemic and the related policy responses. Data and methodology. The analysis consisted of the three stages: first, we processed the official epidemiologic data related to the coronavirus pandemic and the territorial patterns of infections as well as the data on the socio-economic impacts of the lockdown (on retail trade, employment, tourism, local governments’ revenues, etc.). Second, we collected the data related to the socio-economic effects of the pandemic and revealed the territorial impacts of the crisis. Finally, we evaluated the government’s measures and interventions introduced in the first wave of the pandemic in terms of their efficiency. Results Our results demonstrate that while the epicentre of the pandemic was the capital city and its surrounding area, the socio-economic impacts of containment measures implemented by the Hungarian government were felt across the whole country. In some areas, the lockdown measures could have been unreasonably tight as no reasonable justification for these restrictions was provided. Therefore, territorial monitoring and development of regionally differentiated policies are the main tasks in preparation for further waves of the pandemic. In our opinion, it is necessary to devise an action plan that would regulate the protocols of prevention and protection in connection with the regional focal points (hospitals, nursing homes, schools, etc.) and their immediate surroundings. Conclusions. Although territorial aspects have been taken into account by the government in their efforts to contain the pandemic in Hungary, they have been given significantly less attention in terms of socio-economic support. Thus, as the article makes clear, it is important to devise and implement regionally differentiated policies of containment as well as socio-economic protection measures.Актуальность. Новая пандемия коронавируса (COVID-19) внесла серьезные изменения в повседневную жизнь и экономику в 2020 году. Воздействие пандемии по-прежнему трудно измерить и интерпретировать. В данной статье анализируются ключевые социально-экономические факторы, которые сформировали течение пандемии и ее региональные последствия в Венгрии. Цель исследования. Цель этого документа – предоставить вторичный анализ региональных различий в Венгрии на основе данных, а также последствий пандемии коронавируса и соответствующих ответных мер правительства. Данные и методы. Анализ состоял из трех этапов: во-первых, мы обработали официальные эпидемиологические данные, связанные с пандемией коронавируса и территориальными структурами инфекций, а также данные о социально-экономических последствиях ограничений (на розничную торговлю, занятость, туризм, доходы органов местного самоуправления и т.д.). Во-торых, мы собрали данные о социально-экономических последствиях пандемии и выявили территориальные последствия кризиса. Наконец, мы оценили меры вмешательства правительства, введенные в ходе первой волны пандемии, с точки зрения их эффективности. Результаты. Наши результаты показывают, что, хотя эпицентром пандемии была столица и ее окрестности, социально-экономические последствия ограничительных мер, введенных правительством Венгрии, ощущались по всей стране. В некоторых районах меры изоляции могли быть неоправданно жесткими, поскольку не было предоставлено разумного обоснования для этих ограничений. Следовательно, территориальный мониторинг и разработка регионально дифференцированной политики являются основными задачами при подготовке к новым волнам пандемии. По нашему мнению, необходимо разработать план действий, который регулировал бы профилактику и защиту в координации с региональными центрами (больницами, домами престарелых, школами и т.д.) и их непосредственным окружением. Выводы. Хотя территориальные аспекты были приняты во внимание правительством в усилиях по сдерживанию пандемии в Венгрии, им уделялось значительно меньше внимания с точки зрения социально-экономической поддержки. Таким образом, как поясняется в статье, важно разработать и реализовать дифференцированную по регионам ограничительную политику, а также меры социально-экономической защиты

Psychometric properties of the Alcohol Use Disorders Identification Test (AUDIT) across cross-cultural subgroups, genders, and sexual orientations: Findings from the International Sex Survey (ISS)

Introduction. Despite being a widely used screening questionnaire, there is no consensus on the most appropriate measurement model for the Alcohol Use Disorders Identification Test (AUDIT). Furthermore, there have been limited studies on its measurement invariance across cross-cultural subgroups, genders, and sexual orientations. Aims. The present study aimed to examine the fit of different measurement models for the AUDIT and its measurement invariance across a wide range of subgroups by country, language, gender, and sexual orientation. Methods. Responses concerning past-year alcohol use from the participants of the cross-sectional International Sex Survey were considered (N=62,943; Mage: 32.73; SD=12.59). Confirmatory factor analysis, as well as measurement invariance tests were performed for 21 countries, 14 languages, three genders, and four sexual-orientation subgroups that met the minimum sample size requirement for inclusion in these analyses. Results. A two-factor model with factors describing ‘alcohol use’ (items 1-3) and ‘alcohol problems’ (items 4-10) showed the best model fit across countries, languages, genders, and sexual orientations. For the former two a variance and covariance level of invariance, while for gender and sexual orientation a latent mean level of invariance was reached. Conclusions. In line with the two-factor model, the calculation of separate alcohol-use and alcohol-problem scores is recommended when using the AUDIT. The high levels of measurement invariance achieved for the AUDIT support its use in cross-cultural research, capable also of meaningful comparisons amongst genders and sexual orientations

Covalently bonded three-dimensional carbon nanotube solids via boron induced nanojunctions

The establishment of covalent junctions between carbon nanotubes (CNTs) and the modification of their straight tubular morphology are two strategies needed to successfully synthesize nanotube-based three-dimensional (3D) frameworks exhibiting superior material properties. Engineering such 3D structures in scalable synthetic processes still remains a challenge. This work pioneers the bulk synthesis of 3D macroscale nanotube elastic solids directly via a boron-doping strategy during chemical vapour deposition, which influences the formation of atomic-scale “elbow” junctions and nanotube covalent interconnections. Detailed elemental analysis revealed that the “elbow” junctions are preferred sites for excess boron atoms, indicating the role of boron and curvature in the junction formation mechanism, in agreement with our first principle theoretical calculations. Exploiting this material’s ultra-light weight, super-hydrophobicity, high porosity, thermal stability, and mechanical flexibility, the strongly oleophilic sponge-like solids are demonstrated as unique reusable sorbent scaffolds able to efficiently remove oil from contaminated seawater even after repeated use

Understanding rational action in infancy

Education and Child Studie