Structure and microwave dielectric properties of Bi- and Ge-doped calcium molybdate

The powders of Ca1–2xBi2xMo1–xGexO4 solid solutions weresynthesized by the conventional solid state method and investigated by X–ray powder diffraction and Raman spectroscopy. The Ca1–2xBi2xMo1–xGexO4 compositions crystallize in scheelite structure (sp. gr. I41/a) at 0 x  0.4, but traces of bismuth germanates are detected by scanning electron microscopy. The x = 0.5 composition contains several phases with BiVO4- type structures. Raman spectroscopy detected the deformation of [BO4]2– polyhedra and changes in B–O bond length (B = Mo, Ge). The energy gaps were calculated from the diffuse scattering spectra by the Kubelka-Munk method. Energy gap (Eg) values decrease with x from 3.29 eV to 2.91 eV, probably due to 6s2 electrons of bismuth in the valence band and changes of the conductivity band by electrons of germanium. Such values of Eg can provide photocatalytical activity of powders under UV and visible light. The electrodynamic parameters of the ceramic sample of Ca1–2xBi2xMo1–xGexO4 were measured by the transmission line method. The average permittivity increases with x from ~10 to ~18 which correlates with theoretical ε, Vmol and total polarizability of samples. An increase in the concentration of bismuth and germanium leads to the additional resonant peaks in the spectra of ε, S11 and S21. These resonant peaks can be probably caused by the appearance of irregular structural domains of Bi atoms or induced by the increased size of grains in the ceramic samples

INVESTIGATION OF POSSIBILITY TO REGISTRER ABSORPTION MOLECULAR SPECTRA BY THE SPECTROMETER CONTRAA 700

As a result of the study, the possibility of recording molecular absorption by the spectrometer ContrAA 700 was experimentally verified. This absorption is formed in the graphite furnace by means of complex thermochemical processes occurring in the gas headlight and on the surface of the graphite furnace

87Sr/86Sr ISOTOPE RATIOS IN THE RIVER WATERS OF THE SOUTHERN URALS

87Sr/86Sr isotopic ratios are widely used to identify strontium sources and study strontium behaviour in (bio)geochemical cycles. 87Sr/86Sr in surface waters can reflect the average composition of bioavailable (i.e. available for further absorption by plants and animals) strontium in the catchment specific area. Based on those 87Sr/86Sr ratios, the regional maps of the bioavailable strontium distribution (strontium isoscapes) can be compiled. A complex block structure characterizes the Ural mountain system. Individual parts (blocks) are composed of rocks of various ages, genesis and geochemical characteristics, which can radically change at a distance of several tens of kilometres. Such variability would be reflected in strontium isotopic ratios, thus making it possible to determine the local isotopic signatures of bioavailable strontium. This work aimed to study 87Sr/86Sr in the water in the rivers of the Southern Urals. We determined the contents and isotopic ratios of strontium in river water samples collected from the territories of the Orenburg and Chelyabinsk regions and the Republic of Bashkortostan in 2019-2020. For the first time in the surface water of the rivers in the Southern Urals (Ural, Belaya, Tobol, Karagaily-Ayat, Sim, and others), the 87Sr/86Sr isotopic ratios have been determined, and their variations have been analyzed. 87Sr/86Sr values vary in the range 0.70666-0.71063 (average 0.70908) for the rivers of the Urals basin, 0.70749-0.71058 (average 0.70924) for the Kama-Volga basin, 0.70946-0.71176 (average 0.71071) for the Tobol basin. Such features of the strontium isotopic composition may be due to the influence of underlying rocks of the catchment area drained by river water. The data obtained can be used to identify the sources of strontium input into the water system during hydrological and environmental studies; to confirm the authenticity of food products of plant and animal origin; to carry out comparisons in the studies of the migration of ancient people and animals, as well as to determine the raw material areas for the production of vegetable and woollen textiles and wooden products in antiquity. © 2022 Institute of the Earth's Crust. All rights reserved.Russian Foundation for Basic Research, РФФИ: 20-09-00194; Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-680The study is supported by the Russian Foundation for Basic Research (project 20-09-00194) and performed within the state task of the IGG UB RAS АААА-А18-118053090045-8 at the "Geoanalitik" shared research facilities of the IGG UB RAS. The re-equipment and comprehensive development of the "Geoanalitik" shared research facilities of the IGG UB RAS is financially supported by the grant of the Ministry of Science and Higher Education of the Russian Federation (Agreement 075-15-2021-680).FUNDING: The study is supported by the Russian Foundation for Basic Research (project 20-09-00194) and performedwithin the state task of the IGG UB RAS АААА-А 猃稁猃猃稃爃眃甃爃? 爃爃瘃省稀 at the 㘀Geoana?itik 㘀 shared research faci?ities of the IGG UB RAS. The re-equipment and comprehensive deve?opment of the 㘀Geoana?itik 㘀 shared research faci?ities of the IGG UB RAS is 퀀inancia??y supported by the grant of the Ministry of Science and Higher Education of the Russian Federation (Agreement 075-15-2021-680)

MINERALOGICAL AND CHEMICAL COMPOSITION OF THE COLORING PIGMENT OF THE DVUGLAZY KAMEN (TWO-EYED STONE) PICTOGRAPH (THE MIDDLE URALS)

The elemental and mineral composition of the coloring pigment of the Dvuglazy Kamen pre-historic pictograph was studied by the Raman spectroscopy and SEM-EDS. The pigment contains hematite (the most probable mineral component of the paint), gypsum and anhydrite, as well as weddellite.Работа выполнена в ЦКП УрО РАН «Геоаналитик» в рамках темы № АААА-А18-118053090045-8 государственного задания ИГГ УрО РАН и при финансовой поддержке РФФИ в рамках научного проекта № 20-09-00194 А

Assessment of Heavy Metal Contamination of Surface Waters, Soils and Plants in the Orenburg Region

Microelement analysis of surface waters, soils and plants from the Orenburg region was carried out. For V, Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, and Pb a comparison was made with the threshold limit values in drinking water, and the enrichment factors were calculated.Работа поддержана РФФИ (проект № 20-09-00194) и выполнена в ЦКП «Геоаналитик» ИГГ УрО РАН в рамках темы № АААА-А18-118053090045-8 государственного задания ИГГ УрО РАН. Дооснащение и комплексное развитие ЦКП «Геоаналитик» ИГГ УрО РАН осуществляется при финансовой поддержке гранта Министерства науки и высшего образования Российской Федерации, Соглашение № 075-15-2021-680

ИЗОТОПНЫЕ ОТНОШЕНИЯ СТРОНЦИЯ 87Sr/86Sr В ВОДЕ РЯДА РЕК ЮЖНОГО УРАЛА

87Sr/86Sr isotopic ratios are widely used to identify strontium sources and study strontium behaviour in(bio)geochemical cycles. 87Sr/86Sr in surface waters can reflect the average composition of bioavailable (i.e. available forfurther absorption by plants and animals) strontium in the catchment specific area. Based on those 87Sr/86Sr ratios, theregional maps of the bioavailable strontium distribution (strontium isoscapes) can be compiled. A complex block structurecharacterizes the Ural mountain system. Individual parts (blocks) are composed of rocks of various ages, genesis andgeochemical characteristics, which can radically change at a distance of several tens of kilometres. Such variability wouldbe reflected in strontium isotopic ratios, thus making it possible to determine the local isotopic signatures of bioavailablestrontium.This work aimed to study 87Sr/86Sr in the water in the rivers of the Southern Urals. We determined the contents andisotopic ratios of strontium in river water samples collected from the territories of the Orenburg and Chelyabinsk regionsand the Republic of Bashkortostan in 2019–2020.For the first time in the surface water of the rivers in the Southern Urals (Ural, Belaya, Tobol, Karagaily-Ayat, Sim, andothers), the 87Sr/86Sr isotopic ratios have been determined, and their variations have been analyzed. 87Sr/86Sr values varyin the range 0.70666–0.71063 (average 0.70908) for the rivers of the Urals basin, 0.70749–0.71058 (average 0.70924)for the Kama-Volga basin, 0.70946–0.71176 (average 0.71071) for the Tobol basin. Such features of the strontium isotopiccomposition may be due to the influence of underlying rocks of the catchment area drained by river water. The dataobtained can be used to identify the sources of strontium input into the water system during hydrological and environmentalstudies; to confirm the authenticity of food products of plant and animal origin; to carry out comparisons in thestudies of the migration of ancient people and animals, as well as to determine the raw material areas for the productionof vegetable and woollen textiles and wooden products in antiquity.Изотопные отношения стронция 87Sr/86Sr широко используются для выявления источниковстронция и исследования его поведения в (био)геохимических циклах, а в поверхностных водах они могут отражатьусредненный состав биодоступного (доступного для дальнейшего поглощения растениями и животными)стронция на конкретной территории водосбора, на основании чего могут быть составлены региональные картыраспределения биодоступного стронция (Sr изоскейпы). Уральская горная система характеризуется блочнойструктурой, отдельные части (блоки) которой сложены разнообразными по возрасту, генезису и геохимическимособенностям горными породами, которые могут радикально изменяться на расстоянии нескольких десятковкилометров. Такая вариативность будет отражаться и в изотопных отношениях стронция, что позволит с достаточновысокой точностью определить локальные метки биодоступного стронция.Целью работы являлось исследование изотопных отношений стронция 87Sr/86Srв воде ряда рек Южного Урала.В образцах речной воды, отобранных в 2019–2020 гг. с территорий Оренбургской и Челябинской областей и РеспубликиБашкортостан, определены содержания (квадрупольная масс-спектрометрия с индуктивно связаннойплазмой) и изотопные отношения стронция (мультиколлекторная масс-спектрометрия с индуктивно связаннойплазмой и термоионизационная масс-спектрометрия после хроматографического выделения стронция).Впервые в поверхностной воде ряда рек Южного Урала (Урал, Белая, Тобол, Карагайлы-Аят, Сим и др.) определеныизотопные отношения 87Sr/86Sr и проанализированы их вариации. Для рек бассейна р. Урал значения87Sr/86Sr варьируются в диапазоне 0.70666–0.71063 (среднее 0.70908), для бассейна р. Кама – 0.70749–0.71058(среднее 0.70924), для бассейна р. Тобол – 0.70946–0.71176 (среднее 0.71071). Подобные особенности изотопногосостава стронция могут быть обусловлены типом подстилающих горных пород водосбора, дренируемых речнойводой. Полученные данные могут быть использованы для выявления источников поступления стронция в воднуюсистему при гидрологических и экологических исследованиях, для подтверждения аутентичности пищевыхпродуктов растительного и животного происхождения, для проведения сопоставлений при исследованияхмиграций древних людей и животных, а также для определения сырьевых ареалов для производства растительногои шерстяного текстиля, деревянных изделий в древности

Влияние микроволнового облучения на арабиногалактан и его взаимодействие с диацетатом бетулина

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Betulin diacetate (BDA) has a variety of biological activities, but poor solubility in water limits its application. The use of arabinogalactan (AG) as a complexing agent is a promising method for solving the problem of solubilization of drugs. In this study, effect of microwave (MW) irradiation on the properties of AG and BDA and their interaction in aqueous suspension with the formation of a water-soluble supramolecular complex was studied. It is shown that the microwave heating of AG under harsh conditions can lead to degradation of the biopolymer. The use of microwave heating could significantly reduce the complex preparation time compared to the conventional synthesis in a water bath. The preliminary mechanical treatment of the mixture of components, leading to the formation of mechanocomposites, inhibited the reaction between the components in the aqueous suspension under microwave irradiation. The IR spectroscopy method has shown that a supramolecular complex formed under microwave irradiation similar to that formed by conventional heating. The BDA-AG complex was isolated from a microwave heated solution as a thin film, which may be a promising material for pharmaceutical applications

Exigence de proportionnalité et prise en compte des biens communs

International audience(Com. 15 nov. 2017, n° 16-10.504, D. 2018. 392, note M.-P. Dumont-Lefrand ; AJ Contrat 2018. 93, et les obs. ; RTD civ. 2018. 179, obs. P. Crocq ; RTD civ. 2018. 199, obs. M. Nicod

Microwave-assisted synthesis and antitumor activity of the supramolecular complexes of betulin diacetate with arabinogalactan

In this work, a water-soluble supramolecular complex was synthesized in an aqueous suspension of betulin diacetate (BDA) and arabinogalactan (AG) upon microwave heating. Microwave heating allows reducing the time required for the complex formation, compared with conventional heating in a water bath. The specific effect of microwave irradiation on the initial reagents and preparation of a supramolecular complex was studied. In contrast to conventional heating, under microwave heating AG macromolecules may break into roughly equal fragments when the temperature increases up to 100 oC. A change in the surface morphology of BDA crystals under microwave heating of the suspension suggests that microwave irradiation facilitates the dissolution of BDA in water. It has been shown that the use of dimethylsulfoxide as a reaction medium for microwave heating led to a decrease in BDA content in the product due to the inclusion of DMSO into AG macromolecules. The BDA-AG complex was isolated from the microwave-heated aqueous solution, after water evaporation, as a thin amorphous film, which exhibited antitumor activity against Ehrlich ascites carcinoma cells and can be a promising material for pharmacological applications