bluuebunny/crossref_metadata_2025 huggingface dataset:
The spatial extent of hydrological and landscape changes across the mountains and prairies of Canada in the Mackenzie and Nelson River basins based on data from a warm-season time window
Authors: Whitfield Paul H. , Kraaijenbrink Philip D. A. , Shook Kevin R. , Pomeroy John W.
Published: May 2021

Abstract. East of the Continental Divide in the cold interior of Western Canada, the Mackenzie and Nelson River basins have some of the world's most extreme and
variable climates, and the warming climate is changing the landscape, vegetation, cryosphere, and hydrology. Available data consist of streamflow
records from a large number (395) of natural (unmanaged) gauged basins,
where flow may be perennial or temporary, collected either year-round or
during only the warm season, for a different series of years between 1910
and 2012. An annual warm-season time window where observations were available across all stations was used to classify (1) streamflow regime and (2) seasonal trend patterns. Streamflow trends were compared to changes
in satellite Normalized Difference Indices. Clustering using dynamic time warping, which overcomes differences in streamflow timing due to latitude or elevation, identified 12 regime
types. Streamflow regime types exhibit a strong connection to location; there is a strong distinction between mountains and plains and associated with ecozones. Clustering of seasonal trends resulted in six trend patterns that also follow a distinct spatial organization. The trend patterns include one with decreasing streamflow, four with different patterns of increasing streamflow, and one without structure. The spatial patterns of
trends in mean, minimum, and maximum of Normalized
Difference Indices of water and snow (NDWI and NDSI) were similar to each
other but different from Normalized
Difference Index of vegetation (NDVI) trends. Regime types, trend patterns, and satellite indices trends each showed spatially coherent patterns separating the Canadian Rockies and other mountain ranges in the west from the poorly
defined drainage basins in the east and north. Three specific areas of
change were identified: (i) in the mountains and cold taiga-covered
subarctic, streamflow and greenness were increasing while wetness and
snowcover were decreasing, (ii) in the forested Boreal Plains, particularly in the mountainous west, streamflows and greenness were decreasing but wetness and snowcover were not changing, and (iii) in the semi-arid to sub-humid agricultural Prairies, three patterns of increasing streamflow and an
increase in the wetness index were observed. The largest changes in
streamflow occurred in the eastern Canadian Prairies.
Structure optimization of a pipetting device to improve the insertion effect of tips
Authors: Huang Zeng , Wang Chenxue , Su Qian , Lian Zhiping
Published: May 2021

Abstract. In order to solve the problems of the failure of disposable tip insertion which
happens in the pipetting process of most multi-station and high-throughput
pipetting devices, this paper proposes a high-rigidity screw-type pipette
shaft–disposable tip assembly mechanism with excellent auto-centering
effects based on the principle of the ball screw drive. The stiffness model of
the new pipetting device is established, and its stiffness and axial
deformation are analyzed. This new mechanism was introduced to a
multi-station and high-throughput pipetting workstation, and the process of
pipetting disposable tips is simulated by ANSYS software. The analytical results show
that the stiffness value of the new pipetting device is approximately 90 N/µm, and the amount of deformation of the z-axis manipulator is reduced by
about 60 % compared to the original pipetting device. Finally, physical
verification of the prototype was carried out in the work. The test results
show that the new pipetting workstation can increase the tightening rate of
the tips by approximately 12 % after optimization when 96 tips are
inserted in a single press. In addition, the pass rate of the
tightness test of the optimized pipetting workstation has increased by
approximately 20 %.
Center-point steering analysis of tracked omni-vehicles based on skid conditions
Authors: Fang Yuan , Zhang Yunan , Shang Yinghui , Huang Tao , Yan Mengfei
Published: May 2021

Abstract. Existing center-point steering models of a tracked
omni-vehicle seldom consider the skid of the track (roller) grounding
section, which is inconsistent with the actual steering process. In this
study, for the three typical layout types, rectangular, hybrid, and
centripetal, the steady center-point steering motion of a tracked
omni-vehicle under skid conditions is analyzed and a correction model is
investigated. The numerical solution of the absolute lateral offset of the
steering pole is obtained, and the influences of various structural
parameters on the numerical solution are discussed. The steering angular
velocity reduction coefficient is calculated, and the angular velocity of
vehicles is corrected. The simulation of center-point steering motion is
carried out on eight virtual prototypes, and the center-point steering
motion experiment is carried out on three physical prototypes. The results
show that the established correction model is more in line with the steering
reality of the tracked omni-vehicle, and it can play a role in correcting the
center-point steering angular velocity.
Added value of geophysics-based soil mapping in agro-ecosystem simulations
Authors: Brogi Cosimo , Huisman Johan A. , Weihermüller Lutz , Herbst Michael , Vereecken Harry
Published: May 2021

Abstract. There is an increased demand for quantitative
high-resolution soil maps that enable within-field management. Commonly
available soil maps are generally not suited for this purpose, but digital
soil mapping and geophysical methods in particular allow soil
information to be obtained with an unprecedented level of detail. However, it is often
difficult to quantify the added value of such high-resolution soil
information for agricultural management and agro-ecosystem modelling. In
this study, a detailed geophysics-based soil map was compared to two
commonly available general-purpose soil maps. In particular, the three maps
were used as input for crop growth models to simulate leaf area index (LAI)
of five crops for an area of ∼ 1 km2. The simulated
development of LAI for the five crops was evaluated using LAI obtained from
multispectral satellite images. Overall, it was found that the
geophysics-based soil map provided better LAI predictions than the two
general-purpose soil maps in terms of correlation coefficient R2, model
efficiency (ME), and root mean square error (RMSE). Improved performance was
most apparent in the case of prolonged periods of drought and was strongly
related to the combination of soil characteristics and crop type.
Hourly surface meltwater routing for a Greenlandic supraglacial catchment across hillslopes and through a dense topological channel network
Authors: Gleason Colin J. , Yang Kang , Feng Dongmei , Smith Laurence C. , Liu Kai , Pitcher Lincoln H. , Chu Vena W. , Cooper Matthew G. , Overstreet Brandon T. , Rennermalm Asa K. , Ryan Jonathan C.
Published: May 2021

Abstract. Recent work has identified complex perennial supraglacial stream and river
networks in areas of the Greenland Ice Sheet (GrIS) ablation zone. Current
surface mass balance (SMB) models appear to overestimate meltwater runoff in
these networks compared to in-channel measurements of supraglacial
discharge. Here, we constrain SMB models using the hillslope river routing
model (HRR), a spatially explicit flow routing model used in terrestrial
hydrology, in a 63 km2 supraglacial river catchment in southwest
Greenland. HRR conserves water mass and momentum and explicitly accounts for
hillslope routing (i.e., flow over ice and/or firn on the GrIS), and we produce
hourly flows for nearly 10 000 channels given inputs of an ice surface digital elevation model (DEM),
a remotely sensed supraglacial channel network, SMB-modeled runoff, and an
in situ discharge dataset used for calibration. Model calibration yields a
Nash–Sutcliffe efficiency as high as 0.92 and physically realistic
parameters. We confirm earlier assertions that SMB runoff exceeds the
conserved mass of water measured in this catchment (by 12 %–59 %) and that
large channels do not dewater overnight despite a diurnal shutdown of SMB
runoff production. We further test hillslope routing and network density
controls on channel discharge and conclude that explicitly including
hillslope flow and routing runoff through a realistic fine-channel
network (as opposed to excluding hillslope flow and using a coarse-channel
network) produces the most accurate results. Modeling complex surface water
processes is thus both possible and necessary to accurately simulate the
timing and magnitude of supraglacial channel flows, and we highlight a need
for additional in situ discharge datasets to better calibrate and apply this
method elsewhere on the ice sheet.
Sources of Uncertainty in Greenland Surface Mass Balance in the 21st century
Authors: Holube Katharina M. , Zolles Tobias , Born Andreas
Published: May 2021

Abstract. The surface mass balance (SMB) of the Greenland Ice Sheet is subject to considerable uncertainties that complicate predictions of sea level rise caused by climate change. We examine the SMB of the Greenland Ice Sheet in the 21st century with the surface energy and mass balance model BESSI. To estimate the uncertainty of the SMB, we conduct simulations for four greenhouse gas emission scenarios using the output of a wide range of climate models from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to force BESSI. In addition, the uncertainty of the SMB simulation is estimated by using 16 different parameter sets in our SMB model. The median SMB across climate models and parameter sets, integrated over the ice sheet, decreases over time for every emission scenario. As expected, the decrease in SMB is stronger for higher greenhouse gas emissions. The regional distribution of the resulting SMB shows the most substantial SMB decrease in western Greenland for all climate models, whereas the differences between the climate models are most pronounced in the north and in the area around the equilibrium line. Temperature and precipitation are the input variables of the snow model that have the largest influence on the SMB and the largest differences between climate models. In our ensemble, the range of uncertainty in the SMB is greater than in other studies that used fewer climate models as forcing. An analysis of the different sources of uncertainty shows that the uncertainty caused by the different climate models for a given scenario is larger than the uncertainty caused by the climate scenarios. In comparison, the uncertainty caused by the snow model parameters is negligible, leaving the uncertainty of the climate models as the main reason for SMB uncertainty.
Healthcare Students’ Perception of Social Distancing during the 2019 Coronavirus Pandemic: A Cross-Sectional Survey
Authors: Barrett Devon L , Rainer Katharine W , Zhang Chao , Blalock Travis W
Published: May 2021

Background: Since the implementation of social distancing practices during the global coronavirus disease 2019 (COVID-19) pandemic there have been a myriad of definitions for ‘social distancing.’ The objective of this study was to determine students’ awareness of the various definitions of social distancing, how strictly they adhered to social distancing guidelines, and how they perceived the importance of various social distancing practices. 

Methods: This cross-sectional survey was distributed via email to students at Emory-affiliated graduate schools, including the Medical, Nursing, and Public Health Schools.

Results: Of the 2,453 recipients of the survey, 415 students responded (16.9% response rate). The majority of respondents were medical students (n=225, 55.6%). Of the respondents, 357 noted that they “frequently” or “always” abided by social distancing. The most common definition of social distancing with which respondents were familiar was the Centers for Disease Control and Prevention (CDC)’s (n=276 of 369 responses, 74.8%). There were significant differences across groups  when grouping students by the definition of social distancing that they were aware of, the social distancing guideline they most closely followed, and their school of attendance regarding the importance of specific social distancing examples (p<0.05 for each).

Conclusions: A survey of healthcare students identified differences in the importance of social distancing practices based on the definition of social distancing that they were aware of. The results of this study underscore the importance of having unified definitions of public health messaging, which ultimately may impact disease spread.
Impact of Effectiveness of Early Childhood Education on Students Learning Outcomes in Pakistan
Authors: Nawaz Asifa , Ashraf Ijaz , Siddique Aisha
Published: May 2021

Learning occurs faster in the early years of life. Early Childhood Education (ECE) programs generally entail an acquisition of concepts, skills, and attitudes that lay the foundation for school readiness. This study aimed to examine the effectiveness of ECE on students learning outcomes and highlight problems related to the implementation of ECE program in District Faisalabad of Punjab province, Pakistan. All the teachers managing these ECE centres in Government schools of District Faisalabad were the population for the study. There were 313 ECE schools, and a sample of 173 ECE teachers was selected randomly (one teacher from each school). A well-structured questionnaire was used for data collection. The collected data was analysed through SPSS, and the results were interpreted. It was concluded that a lot of challenges existed. These include untrained ECE teachers, lack of financial resources, lack of learning and physical facilities, continuous mentoring and evaluation, and lack of awareness of the significance of ECE among people. These also have a significant influence on the effectiveness of the ECE program. In Consequence, the effectiveness of ECE programme has a significantly positive impact on students learning outcomes. It was recommended that emphasis should be placed to improve the provision of ECE and to address the problems related to its implementation. And That government should introduce a proper system for effective monitoring and evaluation to maintain a conducive environment for learning and for complete mainstreaming of the ECE program.
FAUNAL REVIEW OF HORSEFLIES OF THE AKMOLA REGION
Authors: Akimbekova Almagul Fazylkarimovna , Arystanbay Ayaulym Adilgazykyzy
Published: May 2021

Data on the species composition and ecology of horseflies in the study area are presented. The habitation of horseflies belong to five genera has been established. 25 species of horseflies were identified in the study area. Under favorable climatic conditions, there is an increase in the number of horseflies. The terms of activity and number of horseflies on pastures of cattle and horses were studied.
BINARY OPPOSITION «SADNESS-JOY» IN RUSSIAN AND ENGLISH LANGUAGES
Authors: Tadzhibova Z.T.
Published: May 2021

The article is devoted to a comparative study of the binary opposition of the concepts «sadness-joy» in the idiomatic picture of the world of multi-system languages. The author identifies such thematic groups for the implementation of these concepts as «joke», «rejoice», «grieve», «be happy», «be sad, sadness». In the course of the study, a coincidence was found in linguistic cultures in relation to these concepts, when the connection between sadness and joy is emphasized, it is called upon to endure difficult moments of life and not to despair, it is recommended not to make hasty conclusions. A separate group can be combined with proverbs that reveal the attitude of Russians and British to happiness. Based on the material received, several principles can be distinguished that express the attitude towards happiness. First, no one chooses happiness, and in this case, it is understood as «luck, luck» and is given from above. Secondly, happiness,
as opposed to the first group of proverbs, is perceived as a category that must be achieved / earned / deserved. Thirdly, proverbs were discovered in which happiness is an important part of the life of stupid people and most often they get it. The author comes to the conclusion that these concepts are universal in all the studied linguocultures, but their implementation, reflected in the plane of the paremiological picture of the world, is specific.
GERMAN SLOGANS REPRESENTING GERMANY
Authors: Gordeeva Natalia Vladimirovna
Published: May 2021

German slogans are examined in the article. The peculiarities of slogan and its types are indicated. The examples of German slogans representing the Federal Lands of Germany are given. The attractiveness, the individuality of the Lands, the call to visit them is reflected in the German slogans.
A DINÂMICA DAS DECISÕES JURISDICIONAIS COLEGIADAS
Authors: Guimarães Sepulveda Antônio , Lazari Igor , Carlos Rocha Kayat Roberto
Published: May 2021

Decisões colegiadas sujeitam-se a problemas de agregação. Estes problemas, porém, são distintos a depender da composição do colegiado, da expertise de seus membros e dos mecanismos de interação derivados do desenho decisório. Neste desiderato, o funcionamento de colegiados jurisdicionais pode até mesmo ser contraintuitivo, produzindo deliberações que não correspondam às decisões individuais (votos) de seus membros, o que revela aspecto peculiar das deliberações coletivas, com implicações a nível constitucional e legal. Abordam-se aqui dois fenômenos correlatos ao tema, a saber, o Paradoxo Doutrinal e a Propriedade Emergente, os quais demonstram que colegiados podem mesmo vir a pôr em risco valores como a racionalidade e a segurança jurídica das decisões.
AS IMPENHORABILIDADES À LUZ DO NOVO CÓDIGO DE PROCESSO CIVIL
Authors: Barros Sales Gabriela
Published: May 2021

O presente texto aborda a questão das impenhorabilidades de bens do devedor com as principais mudanças trazidas pelo Novo Código de Processo Civil em comparação ao Código de Processo Civil de 1973. Além disso, traz as principais questões controvertidas sobre o tema, bem como o entendimento jurisprudencial e a relativização das impenhorabilidades.
A PETIÇÃO INICIAL COMO FATO JURÍDICO PROCESSUAL
Authors: CORREA GONÇALVES DE REZENDE PRISCILLA
Published: May 2021

Pautado na visão do direito como um sistema formado por um conjunto de normas jurídicas válidas, o presente artigo busca mostrar que a petição inicial (devidamente protocolada e com os seus pressupostos mínimos de formação) constitui fato jurídico processual, atuando como antecedente de norma secundária. Sendo assim, requer atividade enunciativa, no caso exercida pelo autor. Tal constatação é importante para concluir que a petição inicial consiste em pressuposto lógico de formação do processo, que, por sua vez, é a relação jurídica movimentada nos termos e limites estabelecidos na exordial.
A NECESSIDADE DE SE FALAR NA (DUPLA DIMENSÃO DA) TEORIA DA RESPOSTA CORRETA EM DIREITO PROCESSUAL
Authors: Becker Isaia Cristiano , Andrade Obaldia Bruna , Lameira Gasparetto Hígor
Published: May 2021

O presente trabalho busca investigar o importante debate estabelecido entre Herbert Hart e Ronald Dworkin acerca das decisões judiciais em face de casos difíceis. Para que isso seja possível o estudo foi dividido em três seções. Inicia-se pela compreensão dos elementos principais do debate em tela, tratando desde a concepção hartiana de poder discricionário dos juízes até o anti-relativismo dworkiniano que nega esse poder. Em um segundo momento, o ensaio ocupa-se especificamente com a teoria da resposta correta proposta por Dworkin como mecanismo de afastamento da discricionariedade judicial, tratando dos seus deveres de coerência e integridade, além de abordar a dupla dimensão que a caracteriza. O terceiro capítulo, por sua vez, detém-se em propiciar a visualização dos temas abordados nas seções anteriores na seara do direito processual propriamente dito, relacionando diretamente o enfoque anti-relativista e hermenêutico ao processo civil brasileiro. Ante a isso, questiona-se: em que medida (ainda) é necessário discutir sobre a impossibilidade de decisões discricionárias e, no mesmo sentido, estabelecer parâmetros decisórios que afastem essa subjetividade no terreno do direito processual? Para responder a problemática levantada, o trabalho se utiliza uma abordagem fenomenológico-hermenêutica, além de adotar o viés procedimental monográfico e a técnica de pesquisa bibliográfica. Ao final, o estudo permite depreender que ainda é necessário se falar em discricionariedade judicial. Ademais, os parâmetros que afastam a subjetividade são aqueles delineados para a construção de respostas corretas em suas duas dimensões - a interpretativa e a procedimental: integridade, coerência, adequada fundamentação por argumentos de princípio e o respeito às garantias processuais, principalmente a participação dos interessados/afetados pelo provimento.
Women and Corruption
Authors: Akhmetova Elmira
Published: May 2021

Transparency International, the global coalition against corruption, defines corruption as “the abuse of entrusted power for private gain. It hurts everyone who depends on the integrity of people in a position of authority.” Corruption has a devastating impact on the social, economic, ethical and mental wellbeing of human beings as an individual and community. In Islam, any form of corruption (fasad) like bribery, extortion, kickback and illegal gratuity are strictly prohibited by the texts. The Qur´an enjoins the believers not to consume their property among themselves unjustly and not to give bribes to the rulers that may sinfully and knowingly lead to devouring of the property of others (al-Baqarah 2:188). In several other verses, the text also condemns all forms of economic and political oppression and proscribes spreading of mischief and corruption on the earth (al-Qasas 28:4 and al-A’raf 7:56).  The Prophet Muhammad (peace be upon him) has said that the bribe-taker, the bribe-giver and their mediator, all of them invoke God’s wrath.
Lector Intende, Laetaberis: A Research-Based Approach to Introductory Latin
Authors:   College of the Holy Cross, Libatique Daniel , Machado Dominic ,   College of the Holy Cross
Published: May 2021

In the 2019-20 academic year, we undertook a full redesign of our introductory Latin curriculum at the College of the Holy Cross in order to provide students with a more meaningful encounter with the Latin language. We primed our students to work with real, unedited Latin texts within their first year of study by highlighting Latin grammatical concepts that were frequent, complex, and unfamiliar to English speakers, which meant introducing topics like the passive voice, the subjunctive, third-declension adjectives, and indirect statement that are foundational to the Latin language much earlier than we had previously.
In Search of Helen Maria Chesnutt (1880-1969), Black Latinist
Authors:   Wayne State University, Ronnick Michele
Published: May 2021

Classical scholars have begun to delineate the dynamic pattern of black classicism. This new subfield of the classical tradition involves the analysis of the creative response to classical antiquity by artists as well as the history of the professional training in classics of scholars, teachers and students in high schools, colleges and universities. To the first group belongs Helen Maria Chesnutt (1880-1969). Born in Fayetteville, NC, Chesnutt was the second daughter of acclaimed African American novelist, Charles W. Chesnutt (1858-1932). She earned her B.A. from Smith College in 1902 and her M.A. in Latin from Columbia University in 1925. She was a member of the American Philological Association and the Classical Association of the Middle West and South. Her life was spent teaching Latin at Central High School in Cleveland, OH. This is the first full scale account of her career.
Full Circle: Juvenal’s Egyptians and the Return of the “Angry White Man” in Satire 15
Authors:   Smith College, Shumate Nancy
Published: May 2021

Some critics have seen a softening of Juvenal’s signature anger in the later satires, while others argue, on the contrary, that the indignatio animating the earlier poems resurfaces toward the end of the corpus. This paper supports the second position by comparing the characterization of speakers in the first six satires and in the fifteenth. In spite of its different setting and quasi-philosophical trappings, the (virtually) last poem’s speaker emerges as a variation of the same reactionary character type so fully drawn in the first two books. The Satires are thus framed by prototypes of the grievance-driven “angry white man” of later eras.
ANISOTROPY OF ATTENUATION OF ACOUSTIC WAVES IN PHOTOREFRACTIVE BSO AND BGO CRYSTALS
Authors: Akhmedzhanov F.R. , Saidvaliev U.A. , Kurbanov J.O.
Published: May 2021

Anisotropy of attenuation of acoustic waves in photorefractive BSO and BGO crystals has been studied in the frequency range of 0.4−1.6 GHz. The anisotropy parameters determined by the imaginary constants of BSO and BGO crystals are equal 0.58 and 0.52, respectively. It is shown that the most contribution of dielectric loss to the attenuation of acoustic waves is observed for the piezoactive transversal waves propagating in the (100) plane.
ВЛИЯНИЕ ИЗМЕНЕНИЯ ХИМИЧЕСКОГО ПОТЕНЦИАЛА НА ТЕПЛОЕМКОСТЬ КВАЗИДВУМЕРНОГО ЭЛЕКТРОННОГО ГАЗА
Authors: Байматов П.Ж. , Гулямов А.Г. , Абдулазизов Б.Т. , Султонов Б.К.
Published: May 2021

Представлены численные результаты исследования термодинамических свойств квазидвумерного электронного газа: плотность состояний, производная по температуре от химического потенциала и теплоемкость газа. Найдены зависимости этих величин от химического потенциала. Показано, что плотность состояний имеет ступенчатый характер, а в зависимости теплоемкости в точках резонанса существуют дополнительные ступеньки. Ширина дополнительных ступенек растет с температурой. С ростом температуры, когда основные ступеньки практически размыты, от дополнительных ступенек ещё остаются заметные следы.
ОПРЕДЕЛЕНИЕ АКТИВНОСТИ ИЗОТОПОВ В ПРОДУКТАХ ДЕЛЕНИЯ ЯДЕРНОГО ТОПЛИВА
Authors: Байтелесов С.А. , Кудиратов С.Н. , Кунгуров Ф.Р.
Published: May 2021

Ядерное топливо типа ИРТ-4М из активной зоны исследовательского реактора ВВР-СМ выгружалось каждый раз при различных выгораниях. Активности изотопов в продуктах деления, выходящих из ядерного топлива, измерены и сравнены с максимально допустимыми значениями. В результате определено, что активность всех нуклидов в продуктах деления ядерного топлива ниже максимально допустимого предела. Обнаружено что активность нуклидов в продуктах деления ядерного топлива увеличивается с возрастанием выгорания. Сделан вывод, что ядерное топливо типа ИРТ-4М может быть использовано в активной зоне до значений более 50% выгорания без вреда для эксплуатации и радиационной обстановки реактора.
ДИФФУЗИОННАЯ ЭВОЛЮЦИЯ ЭЛЕКТРОМАГНИТНЫХ ВОЗМУЩЕНИЙ В СВЕРХПРОВОДНИКАХ
Authors: Тайланов Н.А. , Джураева Н.М. , Бобонов Д.Т. , Маматкулов Б.Х. , Суярова М.Х. , Самадов М.Х.
Published: May 2021

В данной работе исследована диффузионная эволюция малых электромагнитных возмущений в сверхпроводнике второго рода, который находится в режиме вязкого течения потока. Получены аналитические формулы для глубины и скорости проникновения магнитного поля в сверхпроводник в зависимости от значений параметра задачи.
ОБРАЗОВАНИЕ ЗАРЯЖЕННЫХ СОСТОЯНИЙ НА ПОВЕРХНОСТИ ZnO ПРИ НИЗКОЭНЕРГЕТИЧЕСКОМ ОБЛУЧЕНИИ ЭЛЕКТРОНАМИ
Authors: Шаропов У.Б. , Курбанов С.С. , Атабаев Б.Г. , Джаббарганов Р. , Мирзахмедов И. , Худайкулов Ф. , Жабборов Х.
Published: May 2021

Исследовано дефектообразование на поверхности оксида цинка с применением низко-энергетических электронов методом спектроскопии полного тока. Показано образование катионных и анионных вакансий на поверхности. Определен энергетический порог образования вакансии аниона (~20 эВ) на поверхности ZnO.
ВЛИЯНИЕ БОМБАРДИРОВКИ ИОНАМИ Ar+ НА ЭЛЕКТРОННЫЕ И ОПТИЧЕСКИЕ СВОЙСТВА ПЛЕНОК CdS
Authors: Содикжанов Ж.Ш. , Мирзаев Д.А. , Мирджалилова М.А. , Ташмухамедова Д.А. , Умирзаков Б.Е.
Published: May 2021

Изучено влияние бомбардировки ионами Ar+ на состав, зонно-энергетические параметры и оптические свойства пленок CdS. Показано, что при низких дозах ионов Ar+ (D ≤ 5×1015 см−2) поверхность обогащается атомами S, а при высоких дозах (D ≥ 5×1015 см−2) атомами Cd.
ВЛИЯНИЕ АТОМОВ ЭРБИЯ, ЛАНТАНА И РОСТОВЫХ ПРИМЕСЕЙ НА ЭФФЕКТИВНОСТЬ ОБРАЗОВАНИЯ РАДИАЦИОННЫХ ДЕФЕКТОВ В КРЕМНИИ
Authors: Далиев Ш.Х. , Мамадалимов А.Т. , Бекмуратов М.Б.
Published: May 2021

Методами нестационарной емкостной спектроскопии изучено влияние примесей эрбия, лантана и кислорода на процессы образования радиационных дефектов в кремнии. Установлено, что присутствие в Si примеси эрбия или лантана приводит к снижению эффективности образования радиационных дефектов. Показано, что концентрации как А-центров, так и Е-центров в 4-5 раз меньше в n-Si или n-Si, облученном γ-квантами 60Со по сравнению с контрольными облученными образцами. Обнаружено, что эффективность образования радиационных дефектов зависит и от содержания кислорода в кремнии.
АНАЛИТИЧЕСКИЙ КОНТРОЛЬ КАЧЕСТВА ОЧИСТКИ ПОВЕРХНОСТИ ПРИ ИОННОМ, ИОННО-ПЛАЗМЕННОМ ВОЗДЕЙСТВИИ
Authors: Арустамов В.Н. , Ашуров Р.Х. , Ротштейн В.М. , Ашуров Х.Б. , Худайкулов И.Х.
Published: May 2021

В работе исследованы методы очистки поверхности подложек перед нанесением покрытий вакуумно-плазменными способами. Рассмотрены механический и химический способы очистки, термообработка и обработка тлеющим разрядом. Представлены ИК спектры и спектры комбинационного рассеивания (КР), полученные в результате аналитических исследований состояния поверхности образцов. На основе анализа интенсивностей ИК и КР спектров продемонстрирована зависимость степени чистоты поверхности образцов от применяемого метода очистки.
ДЕФЕКТООБРАЗОВАНИЕ ПРИ НИЗКОТЕМПЕРАТУРНОМ ОТЖИГЕ КРЕМНИЯ, ЛЕГИРОВАННОГО КОБАЛЬТОМ
Authors: Утамурадова Ш.Б. , Олимбеков З.О.
Published: May 2021

С помощью нестационарной емкостной спектроскопии глубоких уровней исследованы процессы низкотемпературного отжига глубоких уровней в кремнии, легированном атомами кобальта. Показано, что в n-Si<Со> при термообработке при 300°С концентрации всех уровней значительно уменьшаются. Определены энергии активации отжига для всех наблюдаемых уровней в n-Si<Со>.
INVESTIGATION OF DEFECT INP(001) SURFACE BY THE METHOD OF LOW ENERGY ION SCATTERING
Authors: Karimov M. , Kutliev U. , Otaboev M.
Published: May 2021

Investigation of grazing scattering of 3 keV Ar+ and Xe+ ions from the defect surface InP(001) are reported. Computer simulations based on the binary collision approximation permit one to carry out a quantitative analysis of data. It is determined that energy distributions of reflected ions directly depend on the defect structure of the topmost surface layer, and these defects form some peaks in low energy part of energy distribution.
ФОТОУПРУГИЕ СВОЙСТВА КРИСТАЛЛОВ МОЛИБДАТА СВИНЦА, ЛЕГИРОВАННЫХ ПРИМЕСЯМИ НАТРИЯ И НЕОДИМА
Authors: Мирзаев С.З. , Ахмеджанов Ф.Р. , Авдиевич В.Н. , Курбанов Ж.О.
Published: May 2021

Методом Диксона в режиме брэгговской дифракции света на акустических волнах определена зависимость фотоупругих свойств кристаллов молибдата свинца, легированных примесями натрия и неодима, от направления поляризации дифрагированного света. Наблюдаемая анизотропия фотоупругости объясняется движением примесных ионов натрия и неодима преимущественно вдоль кристаллографической оси Z.
К ТЕОРИИ БЛИЖНЕГО ПОЛЯ ВОКРУГ ДИЭЛЕКТРИЧЕСКОЙ МИКРОСФЕРЫ
Authors: Юсупов Д.Б. , Сапаев У. , Исмаилова О.Б. , Бозорова Д.Б.
Published: May 2021

В работе обсуждается распределение электромагнитного поля вблизи образца. Полученные результаты сравниваются с результатами раннее развитой теоретической модели для ближнего поля вблизи диэлектрической микросферы с использованием теории скалярных волн и с численными расчётами. Показано, что распределение поля вблизи образца зависит не только от размера, но и от формы нанообразца. Получены явные аналитические формы для компонентов электромагнитного поля и импульса поля вблизи микросферы. Теоретический результат хорошо согласуется с численными расчетами.
ФОТОЧУВСТВИТЕЛЬНОСТЬ МНОГОСЛОЙНОЙ СТРУКТУРЫ С ПОТЕНЦИАЛЬНЫМИ БАРЬЕРАМИ
Authors: Каримов А.В. , Гиясова Ф.А. , Ёдгорова Д.М. , Абдулхаев О.А.
Published: May 2021

Приводятся результаты исследования фоточувствительности гетеропереходной Au-νGaAs:O[1]nCdS-nInP-Au структуры при различных режимах включения. Экспериментально показано, независимо от возбуждаемой поверхности, они отличаются фоточувствительностью в спектральном диапазоне 0.85−0.9 мкм и 1.31−1.55 мкм, что связано с фотогенерационными процессами в высокоомном арсениде галлия и фотоэмиссионными процессами из металла в полупроводник.
ВЛИЯНИЕ ИОНИЗОВАННЫХ ПРИМЕСЕЙ И МИКРОТРУБОК НА ВАХ p-n-4Н-SiC-ПЕРЕХОДА
Authors: Гулямов А.Г. , Жураев Х.Н. , Давлатов А.Б. , Хажиев М.У. , Атабаев Б.Г. , Саидов Д.Ш. , Адилов Н.Б. , Румянцева Е.В.
Published: May 2021

Исследовано влияние ионизованных примесей и микротрубок на напряжение обратного пробоя p-n-перехода на основе 4Н-SiC, полученного методом низкотемпературной диффузии. Показано, что, пользуясь уравнением для напряжений пробоя в зависимости от соотношения пробивных напряжений ВАХ p-n-перехода, можно определить, насколько изменилась концентрация ионизированной примеси и дефектов после травления кристалла и после его отжига.
АНАЛИЗ ХИМИЧЕСКОГО ПОТЕНЦИАЛА ДВУМЕРНОГО ЭЛЕКТРОННОГО ГАЗА ПРИ НИЗКИХ ТЕМПЕРАТУРАХ
Authors: Байматов П.Ж. , Гулямов А.Г. , Абдулазизов Б.Т. , Махмудов А.С.
Published: May 2021

Рассматривается поведение химического потенциала µ двумерного электронного газа вблизи дна минизоны и вдали от нее. Получены низкотемпературные аналитические формулы в условиях существование произвольного числа минизон. Показано, что с ростом температуры вблизи точек резонанса химический потенциал уменьшается линейно, а вдали от нее экспоненциально медленно.
STUDY OF HETEROMOLECULAR INTERACTION OF NONAQUEOUS BINARY SOLUTIONS
Authors: Bozorova D.T. , Gofurov Sh.P. , Kokhkharov A.M. , Ismailova O.B.
Published: May 2021

In this work, the refractometry method was used to study of the molecular interactions and structural characteristics of dimethylformamide-ethanol and cyclohexane-ethanol binary mixtures. The refractive indices of mixtures were measured over a wide range of dimethylformamide and cyclohexane concentrations (0−1.0 mole fractions) at 25°С. It has been shown that heteromolecular complexes in binary solutions are formed at the concentration of ∼0.5 mole fraction of those compounds due to strong H-bonds. Relatively weak interactions are determined at a concentration of ∼0.2 and ∼0.9 mole fraction of dimethylformamide and ∼0.2 and ∼0.8 mole fraction of cyclohexane.
СИНТЕЗ НАНОТРУБОК ФУЛЛЕРЕНА C60 В ОБЪЕМЕ ИСПАРЯЮЩЕЙСЯ КАПЛИ РАСТВОРА
Authors: Махманов У.К.
Published: May 2021

Впервые исследованы особенности зарождения и дальнейшего роста нано- и микроразмерных трубок на основе фуллерена С60 гексагональной формы при испарении изолированной капли раствора C60 в смеси растворителей этилбензол-изопропиловый спирт, расположенной на гладкой поверхности кремниевой подложки. Определены морфологические и размерные характеристики полученных нанотрубок на основе С60 при двух разных концентрациях фуллерена (∼2.4 и ∼2.2 грамм/литр) в исходных каплях. Показано, что поперечное сечение нанотрубки имеет гексагональную форму и значения большой и меньшей диагонали гексагона составляют ∼900 нм и ∼780 нм соответственно при концентрации С60 ∼2.2 грамм/литр. Кроме того, установлено, что внешняя стенка нанотрубки фуллерена C60 шириной ~100−120 нм является монокристаллической и гладкой, внутренняя стенка нанотрубки шириной ~70−90 нм является пористой. Обсуждаются основные физические особенности зарождения и роста нанотрубки С60 внутри испаряющейся капли.
ТЕПЛОВОЕ ПРОСТРАНСТВЕННОЕ СМЕЩЕНИЕ УЛЬТРАКОРОТКИХ ЛАЗЕРНЫХ ИМПУЛЬСОВ ПРИ РАСПРОСТРАНЕНИИ В АТМОСФЕРЕ
Authors: Бахрамов С.А. , Исмаилов М.З. , Касимов А.К.
Published: May 2021

В работе проведены исследования изменения фазы волны излучения мощного фемтосекундного лазера при распространении в атмосфере за счет поглощения излучения средой и образования температурного градиента. Численные эксперименты, проведенные для количественного анализа, показали смещение лазерного луча последующих импульсов в серии при наличии бокового ветра в атмосфере.
ФИЗИЧЕСКИЕ ОСНОВЫ ПОВЫШЕНИЯ РЕНТАБЕЛЬНОСТИ ПРОИЗВОДСТВА ТЕХНИЧЕСКОГО КРЕМНИЯ И КРЕМНИЕВЫХ СПЛАВОВ
Authors: Вечер А.К. , Абдурахманов Б.М. , Курбанов М.Ш.
Published: May 2021

Выплавка технического кремния является наиболее энергоемким и экологически опасным процессом в цепи производства солнечных элементов и изделий электронной техники. Для решения этой проблемы предлагаются новые физически обоснованные способы утилизации наноразмерных пылевых отходов этого производства в бетонах, строительных смесях, керамике, возврата в основное производство в виде брикетов, а также для варки жидкого стекла. Особо отмечено получение на их базе наноразмерных порошков карбида кремния, а также использование пылевых микрочастиц самого технического кремния для создания новых видов преобразователей тепловой энергии.
Самогравитирующий шаровой слой гипотетического релятивистского газа
Authors: Муждабаев И.Ш.
Published: May 2021

В рамках общей теории относительности построена модель равновесной конфигурации, представляющей собой шаровой слой из гипотетического релятивистского газа, в котором возможны отклонения от закона Паскаля, устанавливающего изотропность давления, свойственную идеальной жидкости. Полученная модель может быть использована в описании наблюдательных свойств релятивистского гравитирующего объекта.
ВЛИЯНИЕ ВОЗДЕЙСТВИЯ ОБРАТНЫМ СМЕЩЕНИЕМ НА ПАРАМЕТРЫ СОЛНЕЧНЫХ ЭЛЕМЕНТОВ НА ОСНОВЕ CIGS
Authors: Камилов А.Г.
Published: May 2021

Приведены результаты лабораторных экспериментов по изучению влияния воздействия обратного смещения длительностью 60, 600 и 2000 с. на параметры солнечных элементов (СЭ) на основе поглощающего слоя, состоящего из Cu, In, Ga и Se (CIGS) с различными толщинами буферного слоя CdS. Показано, что для обеспечения стабильной работы СЭ CIGS в естественных условиях эксплуатации толщина их буферного слоя должна быть рассчитана с учетом влияния обратного смещения. Результаты измерений вольтамперных характеристик СЭ CIGS показали, что СЭ с меньшей толщиной буферного слоя CdS более устойчив к воздействию обратного смещения. По результатам измерений вольт-фарадных характеристик выяснено, что при воздействии обратным смещением в темноте емкость структуры увеличивается, что соответствует классической модели влияния обратного смещения, и одинакова для элементов с различной толщиной буферного слоя. После воздействия обратным смещением при освещении емкость структуры и концентрация носителей заряда уменьшается, при этом в меньшей степени в элементах с тонким буферным слоем, что также свидетельствует об их устойчивости к обратному смещению.
Editorial
Authors: Santilli Luca , Crespo Miguel , Davis Higuera Michael
Published: May 2021

Welcome to issue 79 of the ITF Coaching and Sport Science Review. This issue covers a range of aspects in the game including energy demands for different surfaces, the transition to the yellow ball, aerobic fitness training, the commitment of pro players, the influence of height and service performance, variability in technique, and more.
The commitment Challenger Tour players make as junior athletes
Authors: Horne Edward , Haugen Matthew
Published: May 2021

Professional tennis players competing at the Challenger Tour level were interviewed to further understanding of how professionals perceive their advancement. Results showed athletes make extensive commitments to facilitate advancement. Commitments that likely impact their career options after tennis. Implications and suggestions for moving forward are discussed.
The differences in energy system demands of competitive male tennis play between fast and slow courts
Authors: Skorodumova Аnna , Baranov Igor
Published: May 2021

This study investigated the energy system demand differences between matches played on fast courts and on slow courts of high-performance male players. Matches of Grand Slam matches played by Russian players were analysed. External indicators as such in-point playing time as a proportion of total match time were used to conduct the analysis. Data analysis found significant differences in all measured external indicators such as average match playing time, number of points and in-point time. Results also found a significant difference between match motor density (the percentage of total match time that made up effective playing time) for the two surface types, with the slow surface (clay) match motor density being significantly higher than that of the fast surface (grass and hard court), 14.5% and 12.9%, respectively. Subsequent analysis of point length reveals clay courts that slow courts had a significantly higher percentage of points that lasted more than 10 seconds whilst fast courts has a higher percentage of points under 10 seconds in length. It can be concluded that due to the length of the points, tennis primarily employs the ATP-PCr energy system for energy use, dipping into the anaerobic lactic acid energy pathways more on clay court matches. Whilst the aerobic pathways are not employed heavily in-point, they are still essential, possibly even more on clay court due to greater taxation on the anaerobic lactic acid pathway, as they provide the basis for ATP re-synthesis between points. This signals toward endurance as a major component of fitness in tennis.
Execution redundancy: the effect of varying technique for a similar outcome on player’s groundstroke performance
Authors: Davis Higuera Michael
Published: May 2021

Execution redundancy, defined as varying technique for a similar outcome, is a newer defined type of variability which opens new avenues of thinking about tennis training. 19 club-level tennis players were put through different training interventions: low variability where players had to rally to hit a target and maintain technique; and, high variability where players did the same but varied technique slightly. The high variability group improved after a retention period of 1 week in a test of accuracy (measuring average distance of 4 balls hit to a target) and success (measuring number of balls over the net and within a target radius of 500cm). The results suggest that that varying technique for a similar outcome improves performance more than low variability, possibly due mechanisms surrounding increased exploration creating better adapted motor patterns. The results show positive support for variability of this kind of training, but care needs to be taken to ensure that sound biomechanical and technical principles are observed.
The importance of aerobic fitness for tennis: a review (part 1)
Authors: Genevois Cyril
Published: May 2021

Tennis is an intermittent sport involving different physical components, one of which is aerobic fitness. Scientific research has provided information about the physiological demands of tennis competition and some specific protocols have been developed to combine aerobic testing with technical efficiency testing and training. This paper will provide a rationale behind aerobic fitness training for tennis players.
The transition process towards the yellow ball in tennis teaching
Authors: Cortela Caio Corrêa , Fuentes García Juan Pedro , Davis Higuera Michael , Aburachid Layla Maria Campos
Published: May 2021

More than 10 years have gone by since Play and Stay campaign was launched, and even today, there is a lack of scientific studies focusing their strategies on the transition process between the stages that make up Tennis 10s.  So, on the basis of interviews with expert coordinators, who are responsible for sport initiation programmes in Brazilian clubs, this study tries to describe the strategies used for the transition between the “green ball” and the “yellow ball”.
The influence of non-verbal body language on sport performance in professional tennis
Authors: Martínez-Gallego Rafael , Carrillo Molina David
Published: May 2021

The main objective of this study was to analyse the relationship between players´ non-verbal body language and their performance in sport. The sample consists of a total of 477 actions from 40 players competing in the ATP Tour. All actions were taken from tie-breaks in official tournaments. The categories that were analyzed were previous performance, dominant non-verbal body language, submissive non-verbal body language, and performance later on. Results show how the players´ non verbal body language impacts on their performance later on.  Thus, we can conclude that following dominant non-verbal body language, the probabilities of better performance in the next point are greater than following submissive non-verbal body language. Therefore, it is important to train these aspects as an extra tool to improve players´ performance.
Measurement and control of tennis training load: a case study
Authors: Genevois Cyril , Rogowski Isabelle , Le Solliec Tom
Published: May 2021

The objective of this study was to quantify the training load involved in tennis training using relatively simple tools to provide practical information to coaches on the calculation and optimization of the training load, paying particular attention to the session-RPE method, the calculation of the monotony index and the acute to chronic workload ratio calculation. This article presents a case study of a 16-year-old player combining his education with his training in a tennis academy as well as with competition. The daily and weekly training load as well as the other indicators were calculated over 31 weeks and then explained, interpreted and discussed in this article.
The power of attention
Authors: Jiménez Lucía
Published: May 2021

This article attempts to define the concept of attention and characterise its main characteristics in order to better its impact during the learning process as well as on the tennis player's own performance. This is accompanied by examples of exercises as well as guidelines for the improvement of this crucial psychological ability, on and off court.
Management of periapical abscess with Jalaukavcharana (leech application) -A single case study
Authors: Sawant Deepak , Panzade SM
Published: May 2021

Jalaukavacharan is indicated in Vranashotha and advised exclusively in delicate patients for Raktamokshan (blood letting). In this case report a female patient of Pitta-kaphaj Prakruti suffering from periapical abscess due to dental carries was treated with Jalaukavacharan (leech application at cheek) in five sittings weekly once.  The patient was cured completely without any untoward effect. Hence this case highlighted that Jalaukavacharan is effective remedy for management of periapical abscess.
Agnikarma (therapeutic heat application) in Osteoarthritis of Knee joint- A video demonstration
Authors: Pandey Ruchi
Published: May 2021

The Agnikarma is one of the para-sugical procedures mentioned by Sushruta for the management of musculo-skeletol disorders. In geriatric age group osteoarthritis is burning problem which affects the quality of life of an individual. The treatment for OA knee joint includes analgesic, steroid injections and lastly surgery with their own limitations. The purpose of this video presentation of Agnikarma is to demonstrate this procedure to the Ayurveda practioners for the management of OA. During the Post Graduate research work author tried this procedure in 42 patients of OA knee joint. Among them 30 patients were recovered from pain and no pain was noted by those patients during follow up for 6 months. So this simple procedure can be repeated after 6 months. Patient can be free from pain and no need of abuse of analgesic so that old age patient can enjoy the quality of life.