Fingerprints of Critical Phenomena in a Quantum Paraelectric Ensemble of Nanoconfined Water Molecules.

We have studied the radio frequency dielectric response of a system consisting of separate polar water molecules periodically arranged in nanocages formed by the crystal lattice of the gemstone beryl. Below = 20-30 K, quantum effects start to dominate the properties of the electric dipolar system as manifested by a crossover between the Curie-Weiss and the Barrett regimes in the temperature-dependent real dielectric permittivity ε'(). When analyzing in detail the temperature evolution of the reciprocal permittivity (ε') down to ≈ 0.

Single-particle and collective excitations of polar water molecules confined in nano-pores within a cordierite crystal lattice.

Recently, the low-temperature phase of water molecules confined within nanocages formed by the crystalline lattice of water-containing cordierite crystals has been reported to comprise domains with ferroelectrically ordered dipoles within the , -planes which are antiferroelectrically alternating along the -axis. In the present work, comprehensive broad-band dielectric spectroscopy is combined with specific heat studies and molecular dynamics and Monte Carlo simulations in order to investigate in more detail the collective modes and single-particle excitations of nanoconfined water molecules. From DFT-MD simulations we reconstruct the potential-energy landscape experienced by the HO molecules.

Partitioning of REE between calcite and carbonatitic melt containing P, S, Si at 650-900 °C and 100 MPa.

Carbonatites host some unique ore deposits, especially REE, and fractional crystallization might be a potentially powerful mechanism for control enrichment of carbonatitic magmas by these metals to economically significant levels. At present, data on distribution coefficients of REE during fractional crystallization of carbonatitic melts at volcanic conditions are extremely scarce. Here we present an experimental study of REE partitioning between carbonatitic melts and calcite in the system CaCO-NaCO with varying amounts of PO, F, Cl, SiO, SO at 650-900 °C and 100 MPa using cold-seal pressure vessels and LA-ICP-MS.

The behavior of zeolites wairakite and phillipsite at high P-T parameters.

In situ investigation of mineral behavior in water medium at simultaneously high P-T parameters can be applied to modelling of mineral transformation processes in lithospheric plates. The behavior of zeolites wairakite and phillipsite under the P-T conditions of «cold» slab subduction, corresponding to the start of oceanic plate diving or ocean floor near geothermal sources, was studied by in situ Raman spectroscopy. During compression in water medium, phillipsite initial phase is stable up to T = 350 °C, P = 1.

The composition of the fluid phase in inclusions in synthetic HPHT diamonds grown in system Fe-Ni-Ti-C.

Diamonds grown by high pressure high temperature process (HPHT) are usually characterized by yellow color and high contents of nitrogen. Introduction of Ti decreases nitrogen content in diamond. Understanding the formation of nitrogen-poor diamond is very important not for the progress of HPHT process only, but because these diamond varieties represent the rare natural stones, although their crystallization conditions have not been clarified yet.

Immobilized Bisphosphonates as Potential Inhibitors of Bioprosthetic Calcification: Effects on Various Xenogeneic Cardiovascular Tissues.

Calcification is the major factor limiting the clinical use of bioprostheses. It may be prevented by the immobilization of bisphosphonic compounds (BPs) on the biomaterial. In this study, we assessed the accumulation and structure of calcium phosphate deposits in collagen-rich bovine pericardium (Pe) and elastin-rich porcine aortic wall (Ao) and bovine jugular vein wall (Ve) cross-linked with glutaraldehyde (GA) or diepoxy compound (DE).

γ-BaBO: High-Pressure High-Temperature Polymorph of Barium Borate with Edge-Sharing BO Tetrahedra.

The α- and β-modifications of barium metaborate are important functional materials used in optoelectronic devices. A new theoretically predicted modification of BaBO has been synthesized under conditions of 3 GPa and 900 °C, using the DIA-type apparatus. The new high-pressure modification, γ-BaBO, crystallizes in a centrosymmetrical group of monoclinic syngony (2/ (#14), = 4.

NV diamond laser.

For the first time, lasing at NV centers in an optically pumped diamond sample is achieved. A nanosecond train of 150-ps 532-nm laser pulses was used to pump the sample. The lasing pulses have central wavelength at 720 nm with a spectrum width of 20 nm, 1-ns duration and total energy around 10 nJ.

Improved thermoelectric performance of Bi-deficient BiCuSeO material doped with Nb, Y, and P.

Thermoelectric materials convert waste heat into electric energy. Oxyselenide-based material, specifically, p-type BiCuSeO, is one of the most promising materials for these applications. There are numerous approaches to improve the heat-to-electricity conversion performance.

Modern Siberian dog ancestry was shaped by several thousand years of Eurasian-wide trade and human dispersal.

Dogs have been essential to life in the Siberian Arctic for over 9,500 y, and this tight link between people and dogs continues in Siberian communities. Although Arctic Siberian groups such as the Nenets received limited gene flow from neighboring groups, archaeological evidence suggests that metallurgy and new subsistence strategies emerged in Northwest Siberia around 2,000 y ago. It is unclear if the Siberian Arctic dog population was as continuous as the people of the region or if instead admixture occurred, possibly in relation to the influx of material culture from other parts of Eurasia.

Study of an EuBO-ScBO system and EuSc(BO), EuSc(BO) orthoborates.

The EuBO-ScBO system was investigated by solid state synthesis and DSC methods. In this system, a new EuSc(BO) compound was found. It crystallizes in the 3̄ space group with unit cell parameters of = 4.

Sr[CO]O Antiperovskite with Tetrahedrally Coordinated sp-Hybridized Carbon and OSr Octahedra.

We have synthesized the orthocarbonate Sr[CO]O in a laser-heated diamond anvil cell at 20 and 30 GPa by heating to ≈3000 (300) K. Afterward, we recovered the orthocarbonate with [CO] groups at ambient conditions. Single-crystal diffraction shows the presence of [CO] groups, i.

Impact of global cooling on Early Cretaceous high pCO world during the Weissert Event.

The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (the TEX proxy), which capture the Weissert Event in the semi-enclosed Weddell Sea basin, offshore Antarctica (paleolatitude ~54 °S; paleowater depth ~500 meters). We document a ~3-4 °C drop in SST coinciding with the Weissert cold end, and converge the Weddell Sea data, climate simulations and available worldwide multi-proxy based temperature data towards one unifying solution providing a best-fit between all lines of evidence.

Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma.

The discrepancy between Na-rich compositions of modern carbonatitic lavas (Oldoinyo Lengai volcano) and alkali-poor ancient carbonatites remains a topical problem in petrology. Although both are supposedly considered to originate via fractional crystallization of a "common parent" alkali-bearing Ca-carbonatitic magma, there is a significant compositional gap between the Oldoinyo Lengai carbonatites and all other natural compositions reported (including melt inclusions in carbonatitic minerals). In an attempt to resolve this, we investigate the petrogenesis of Ca-carbonatites from two occurrences (Guli, Northern Siberia and Tagna, Southern Siberia), focusing on mineral textures and alkali-rich multiphase primary inclusions hosted within apatite and magnetite.

Lake Ohrid's tephrochronological dataset reveals 1.36 Ma of Mediterranean explosive volcanic activity.

Tephrochronology relies on the availability of the stratigraphical, geochemical and geochronological datasets of volcanic deposits, three preconditions which are both often only fragmentary accessible. This study presents the tephrochronological dataset from the Lake Ohrid (Balkans) sediment succession continuously reaching back to 1.36 Ma.

A comparative study of biota and sediments as monitors of plutonium in the Yenisei River (Siberia, Russia).

MOX-fuel production and spent nuclear fuel reprocessing started recently at the Mining-and-Chemical Combine (MCC, Zheleznogorsk, Russia) have caused an increase in controlled releases of plutonium to the Yenisei River. In this study, we analyzed time-dependent trends of plutonium (Pu and Pu) in biota and bottom sediments of the Yenisei during 2008-2019, to estimate comparatively the potential of abundant representatives of biota as bio-monitors of contamination of the Yenisei by plutonium. Gamma-emitting radionuclides ( K; Co; Cs; Eu; Am) were measured in environmental samples of the Yenisei as well.

1.36 million years of Mediterranean forest refugium dynamics in response to glacial-interglacial cycle strength.

The sediment record from Lake Ohrid (Southwestern Balkans) represents the longest continuous lake archive in Europe, extending back to 1.36 Ma. We reconstruct the vegetation history based on pollen analysis of the DEEP core to reveal changes in vegetation cover and forest diversity during glacial-interglacial (G-IG) cycles and early basin development.

Monitoring and assessment of Cs and Sr radioactive isotopes in the 'soil - rhizosphere - sedge' system of the Yenisei River floodplain (near impact zone of Krasnoyarsk MCC, Russia).

Radiocaesium and radiostrontium contamination in the 'soil - rhizosphere - plants (aerial parts)' system was monitored in the floodplain ecosystem of the Yenisei River in the near impact zone of the Krasnoyarsk Mining and Chemical Combine (MCC). The monitored system included soil, rhizosphere, and sedge vegetation on islands and the river's east bank. The Cs and Sr specific activities displayed intricate space and time patterns controlled by the river water level, including the time and duration of floods and their correlation with the sedge vegetation season.

Micro-Raman Characterization of Structural Features of High-k Stack Layer of SOI Nanowire Chip, Designed to Detect Circular RNA Associated with the Development of Glioma.

The application of micro-Raman spectroscopy was used for characterization of structural features of the high-k stack (h-k) layer of "silicon-on-insulator" (SOI) nanowire (NW) chip (h-k-SOI-NW chip), including AlO and HfO in various combinations after heat treatment from 425 to 1000 °C. After that, the NW structures h-k-SOI-NW chip was created using gas plasma etching optical lithography. The stability of the signals from the monocrine phase of HfO was shown.

Metagenomics data of microbial communities in bacterial mats and bottom sediments in water bodies within the Kurai Mercury Province (Gorny Altai, Russia).

Below is data on the microbial diversity in bottom sediments and microbial mats in water bodies within the Kurai Mercury Province (Ulagan District, Aktash village, Gorny Altai). A database on the geochemical features of water bodies in the study area is presented. Data was obtained using 16 s rRNA amplicon directed metagenomic sequencing on Illumina MiSeq.

Distribution of Cs in lichens, mosses and pine needles along the transect from the north to the south of Western Siberia.

The Cs content in mosses (Hylocomium splendens), lichens (Cladonia stellaris) and the needles of the Siberian pine (Pinus sibirica) and the common pine (Pinus sylvestris) along the transect from the north to the south of Western Siberia from N. 67.5° to N.

Tunable non-integer high-harmonic generation in a topological insulator.

When intense lightwaves accelerate electrons through a solid, the emerging high-order harmonic (HH) radiation offers key insights into the material. Sub-optical-cycle dynamics-such as dynamical Bloch oscillations, quasiparticle collisions, valley pseudospin switching and heating of Dirac gases-leave fingerprints in the HH spectra of conventional solids. Topologically non-trivial matter with invariants that are robust against imperfections has been predicted to support unconventional HH generation.

Assessment of metal pollution and subsequent ecological risk in the coastal zone of the Olkhon Island, Lake Baikal, Russia.

Olkhon Island is the largest island in Lake Baikal and a part of Baikal National Park, Russia. The first objective of this study is to establish relationships between the particle size of accumulating sediments and their elemental composition, as well as the concentrations of heavy metals (Hg, Cd, As, Pb, Cr, Co, Ni, Cu, and Zn). The second goal is to completely assess the contamination level and to identify the possible sources of heavy metals using geochemical indices, including enrichment (EF) and contamination (C) factors, contamination degree (C), geoaccumulation index (I), and pollution load index (PLI).