Fabrication of probes for scanning near-field optical microscopy using focused ion beam

The results were obtained using the infrastructure of the Center for Shared Use “Nanotechnology” of the Southern Federal University

Kinetic parameters of the uranium luminescence in Lif crystals

The results of researches with nanosecond time resolution of kinetic characteristics of luminescence buildup and decay in crystals LiF(U)-O at 300 K under action of both laser pulse with energy 3,68 eV and electron pulse with energy 300 keV have been presented. Influence of excite method on kinetic characteristics of uranium luminescence buildup and influence of uranium on kinetic characteristics of oxygen luminescence in crystal were establishe

Activity of photosystem II in spring barley leaves under the action of manganese ions

The influence of manganese ions (30, 60 and 90 mg/l) on the functioning of the photosystem II (PSII) in leaves was assessed on plants of six spring barley cultivars (Belgorodsky 100, st.). The plants were grown on a complete Knop medium without (control) and with the addition of manganese ions (experiment) under natural light conditions. On 14-day-old leaves, parameters of chlorophyll's rapid fluorescence were recorded using a Fluor Pen FP 110/S fluorometer. The sensitivity of the different structural parts of PSII was found to vary depending on the concentration of Mn ions and the genotype used. Thus, absorbed energy flows increased in the cv. Boyarin at 30 and 60 mg/l Mn (by 7.9 and 14.1 %), in cv. Farmer at 60 and 90 mg/l  (by 15.8 and 16.1 %), but decreased in cv. Dobryak at 30 and 90 mg/l (by 9.7 and 9.0 %), Farmer at 30 mg/l (by 15.8 %) and Bionic at 60 and 90 mg/l (by 8.0 and 6.8 %). The flow of energy stored in primary photochemical reactions in the cv. Bionic increased at 30 mg/l of manganese (by 6.3 %), but decreased at 60 (by 6.8 %) and 90 mg/l (by 5.3 %); increased in the cv. Boyarin at 30 mg/l of Mn (by 6.4 %), but decreased in the cv. Forward (by 11.7 %). Electronic transport leading to CO2 fixation increased in cv. Farmer at all Mn concentrations (by 8.1...12.6 %), and in cv. Bionic it increased at 30 mg/l (by 7.2 %), but decreased at  90 mg/l (by 7.4 %). The electron flux leading to the oxidation of the finile acceptor of PSI in the studied cultivars did not change under the influence of the stressor. However, the integral parameters of PSII activity (PIABS and PIABS_total indices) under stressful conditions were determined by the plant genotype. This indicates, firstly, the need for targeted selection (to a specific level of the stress factor); secondly, on the possibility of pyramidation of the integral level of resistance to the stressor by selecting parents who differ in the level of change in individual functional reactions of photosynthesis

Genotypic variability in the functioning of photosystem II in leaves of covered and naked oats

Background. Comparing the characteristics of primary photosynthetic processes in photosystem II (PSII) in the leaves of two oat (Avena sativa L.) subspecies will help to understand their genetic differentiation. Comparisons between naked and covered oats to assess the efficiency of energy flows within PSII and its relation to useful agronomic traits have not been previously made but can have an effect on their cultivation practices.Materials and methods. Two-week-old plants of 16 covered and 17 naked oat genotypes were assessed for rapid chlorophyll α fluorescence using a Fluor Pen FP 110/S fluorometer. Data on the yield structure were obtained in 2021. The data were processed statistically using descriptive statistics, correlation (Excel 2013) and cluster (StatSoft Statistica 10; Ward's method) analyses.Results. The groups of oat genotypes differed significantly in the absolute magnitude of adsorbed (ABS/RC) and trapped (TRo/RC) light energy flows, which were higher in naked oats (by 7.8 and 7.4%, respectively). The efficiency of electron transfer from plastoquinone QB to PSI in naked oats exceeded that in covered oats by 8.2%. For the whole set of genotypes, a statistically significant correlation of grain yield with the PIABS performance index (r = 0.403), light energy adsorption (r = -0.477) and its utilization at the reaction centers of PSII (r = -0.452) was manifested. The performance indices (PIABS and PIABS_total) positively correlated with part of grain in total biomass (0.571 and 0.418, respectively) and were higher in covered oats (by 28.2 and 21.9%, respectively).Conclusion. The existence of significant differences was shown between covered and naked oats according to six of the nine evaluated structural and functional parameters of the PSII leaf functioning. The results of the cluster analysis demonstrated the tendency to the grouping of genotypes by the presence/absence of grain hullness

Novel technology for fabrication of probe tips for SPM using focused ion beam induced deposition method

The work was done through a grant from the Russian Science Foundation (project No. 18-79-00175) using the equipment of the Research and Education Center and the Nanotechnology Joint Use Center of the Southern Federal University (Taganrog)

Влияние агроландшафта на экологическую устойчивость фитоценозов покровного овса и многолетних трав

Biodiversity is the cornerstone of modern agro-phytocinology. Based on its records, the ecological sustainability of agricultural landscapes is predicted. The aim of the research was to study the influence of soils and the topography of the terminal moraine hill, as well as the age of phytocenoses, on the value of the coefficient of floristic similarity of oat communities with over-sowing of grasses (2019) and clover-and-timothy herbage of 1 year of use (2020). Monitoring of the botanical composition of phytocenoses was carried out on a transect – a field crossing slopes of different exposures and soils of varying degrees of swampiness, located at the agroecological station All-Russian Research Institute of Reclaimed Lands (VNIIMZ; Tver region, Russia). The standing density of oats, red clover, timothy grass, weed species, as well as other environmental parameters were taken into account on 30 systematically located land plots. It is shown that only a few plant species affect the Jaccard coefficient. The topography and soil features of the agricultural landscape, as well as the age of the plant community, have a significant impact on the stability and productivity of the agrocenosis. The main factor affecting the variability of the floristic similarity indicator is soil hydromorphism. An increase in the index of the floristic similarity coefficient is observed on all soils and slopes as the herbage matures. Productivity of grasses depends to the greatest extent on the nature of the interaction of the relief and soils – on the southern slope of the hill, a low hay yield was noted (on average, 5.34 t/ha), the minimum of which was observed on highly swampy soils (4.92 t/ha), on the northern slope, the yield of hay was higher (on average 6.57 t/ha), the minimum of which was noted on moderately swampy soils (6.26 t/ha). Based on the revealed patterns, it is possible to develop measures to adapt technologies for growing perennial grasses to the natural conditions of farms in the mode of adaptive landscape fodder production. Биоразнообразие – краеугольный камень современной агрофитоцинологии. На основе его учета прогнозируется экологическая устойчивость сельскохозяйственных ландшафтов. Цель исследования – изучение влияния почв и рельефа конечно-моренного холма, а также возраста фитоценозов на величину коэффициента флористического сходства сообществ овса с подсевом трав (2019 г.) и клеверо-тимофеечного травостоя 1-го года пользования (2020 г.). Мониторинг ботанического состава фитоценозов осуществлялся на трансекте – поле, пересекающем склоны разной экспозиции и почвы разной степени заболоченности, расположенном на агроэкологическом стационаре Всероссийского научно-исследовательского института мелиорированных земель (ВНИИМЗ; Тверская обл., Россия). Учет густоты стояния овса, клевера красного, тимофеевки луговой, сорных видов, а также других параметров среды проводили на 30 систематически расположенных делянках. Показано, что на коэффициент Жаккара влияет лишь несколько видов растений. Рельефные и почвенные особенности агроландшафта, а также возраст растительного сообщества оказывают существенное воздействие на устойчивость и продуктивность агроценоза. Главным фактором, влияющим на изменчивость показателя флористического сходства, является гидроморфизм почв. На всех почвах и склонах наблюдается увеличение показателя коэффициента флористического сходства по мере взросления травостоя. Продуктивность трав в наибольшей степени зависит от характера взаимодействия рельефа и почв: на южном склоне холма отмечен низкий урожай сена (в среднем 5,34 т/га), минимум которого наблюдался на сильно заболоченных почвах (4,92 т/га), на северном склоне урожай сена был выше (в среднем 6,57 т/га), минимум отмечен на средне заболоченных почвах (6,26 т/га). На основе выявленных закономерностей возможна разработка мероприятий по адаптации технологий выращивания многолетних трав к природным условиям хозяйств в режиме адаптивно-ландшафтного кормопроизводства

Application of focused ion beams for the fabrication of AFM probes

Представлены результаты исследований по формированию острия зондов для АСМ методом фокусированных ионных пучков. Сформированы зонды для методики CD AFM с высотой острия около 1 мкм и радиусом – 20 нм. Применение таких зондов позволяет повысить точность измерения рельефа по сравнению со стандартными зондами.The results of studies on the formation of the AFM probe tips using focused ion beams are presented. Probes for the CD AFM technique with a tip height of about 1 μm and a radius of 20 nm were formed. The use of such probes allows to improve the accuracy of the relief measurement in comparison with standard probes.Работа выполнена в рамках Гранта Президента РФ для государственной поддержки молодых российских ученых - кандидатов наук (Проект № МК-6163.2016.8)

The Campanian Ignimbrite and Codola tephra layers: Two temporal/stratigraphic markers for the Early Upper Palaeolithic in southern Italy and eastern Europe

Tephra layers from archaeological sites in southern Italy and eastern Europe stratigraphically associated with cultural levels containing Early Upper Palaeolithic industry were analysed. The results confirm the occurrence of the Campanian Ignimbrite tephra (CI; ca. 40 cal ka BP) at Castelcivita Cave (southern Italy), Temnata Cave (Bulgaria) and in the Kostenki–Borshchevo area of the Russian Plain. This tephra, originated from the largest eruption of the Phlegrean Field caldera, represents the widest volcanic deposit and one of the most important temporal/stratigraphic markers of western Eurasia. At Paglicci Cave and lesser sites in the Apulia region we recognise a chemically and texturally different tephra, which lithologically, chronologically and chemically matches the physical and chemical characteristics of the Plinian eruption of Codola; a poorly known Late Pleistocene explosive event from the Neapolitan volcanoes, likely Somma–Vesuvius. For this latter, we propose a preliminary age estimate of ca. 33 cal ka BP and a correlation to the widespread C-10 marine tephra of the central Mediterranean. The stratigraphic position of both CI and Codola tephra layers at Castelcivita and Paglicci help date the first and the last documented appearance of Early Upper Palaeolithic industries of southern Italy to ca. 41–40 and 33 cal ka BP, respectively, or between two interstadial oscillations of the Monticchio pollen record – to which the CI and Codola tephras are physically correlated – corresponding to the Greenland interstadials 10–9 and 5. In eastern Europe, the stratigraphic and chronometric data seem to indicate an earlier appearance of the Early Upper Palaeolithic industries, which would predate of two millennia at least the overlying CI tephra. The tephrostratigraphic correlation indicates that in both regions the innovations connected with the so-called Early Upper Palaeolithic – encompassing subsistence strategy and stone tool technology – appeared and evolved during one of the most unstable climatic phases of the Last Glacial period. On this basis, the marked environmental unpredictability characterising this time-span is seen as a potential ecological factor involved in the cultural changes observed

Structural and luminescent characteristics of YAG phosphors synthesized in the radiation field

YAG:Ce, YAGG:Ce ceramics were obtained by sintering the oxide powders in the radiation field. The results of investigations of the structure, composition and luminescence of ceramics are presented. The luminescence characteristics of powders exactly correspond to the phosphors luminescence used in practice obtained by solid-state synthesis methods. It has been established that in the used radiation exposure modes the main factor determining the efficiency of the synthesis is the ionization density

Electron Beam-Assisted Synthesis of YAG:Ce Ceramics

The work was carried out within the framework of the grant AP14870696 of the Ministry of Education and Science of the Republic of Kazakhstan. This research was funded by the Russian Science Foundation of the Russian Federation. (Grant No. 23-73-00108). A.I.P is also thankful for financial support from Latvian Project LZP-2018/1-0214. In addition, A.I.P. is thanking the Institute of Solid State Physics, University of Latvia (ISSP UL). ISSP UL as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2.In this work, we present the results of the structure and luminescence properties of YAG:Ce (Y3Al5O12 doped with Ce3+ ions) ceramic samples. Their synthesis was carried out by sintering samples from the initial oxide powders under the powerful action of a high-energy electron beam with an energy of 1.4 MeV and a power density of 22–25 kW/cm2. The measured diffraction patterns of the synthesized ceramics are in good agreement with the standard for YAG. Luminescence characteristics at stationary/time-resolved regimes were studied. It is shown that under the influence of a high-power electron beam on a mixture of powders, it is possible to synthesize YAG:Ce luminescent ceramics with characteristics close to the well-known YAG:Ce phosphor ceramics obtained by traditional methods of solid-state synthesis. Thus, it has been demonstrated that the technology of radiation synthesis of luminescent ceramics is very promising. © 2023 by the authors. --//-- Karipbayev Z.T., Lisitsyn V.M., Golkovski M.G., Zhilgildinov Z.S., Popov A.I., Zhunusbekov A.M., Polisadova E., Tulegenova A., Mussakhanov D.A., Alpyssova G., Piskunov S.; Electron Beam-Assisted Synthesis of YAG:Ce Ceramics; (2023) Materials, 16 (11), art. no. 4102; DOI: 10.3390/ma16114102; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85161490971&doi=10.3390%2fma16114102&partnerID=40&md5=e33da4c2d44c563881bdeffe410d734b published under the CC BY 4.0 licence.Grant AP14870696 of the Ministry of Education and Science of the Republic of Kazakhstan; Russian Science Foundation of the Russian Federation Grant No. 23-73-00108; the Latvian Council of Science LZP-2018/1-0214; ISSP UL as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2