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Single and multi domain buckled germanene phases on Al(111)surface

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Nano Research 2019年第12期12卷 2988-2996页

作者： Dmitriy A.Muzychenko sergey I.Oreshkin Vladimir I.Panov Chris Van Haesendonck Andrey I.Oreshkin Faculty of Physics Lomonosov Moscow State University119991 MoscowRussia Sternberg Astronomical Institute Lomonosov Moscow State University119234 MoscowRussia Solid-State Physics and Magnetism Section KU LeuvenBE-3001 LeuvenBelgium

The simultaneous formati on of single domain(3×3)and multi domai n(√7×√7)R(±19.1°)germa nene phases on Al(111)surface in thesub-monolayer range was studied using seanning tunneling microscopy(STM)and density functional theory(DFT)based *** results revealed that both germa nene phases nu cleate and grow in dependently from each other and regardless of Al substratetemperature within significantly expanded range Ts=27-200℃.Our results unambiguously showed that STM images with hexagonalcontrast yield correct-resolved structure for both germanene phases,while honeycomb contrast is a result of an artificial tip-induced STM ***-principles calculations suggested atomic models with strongly buckled germanene(2×2)/Al(111)(3×3)and(√3×√3)R30°/Al(111)(√7×√7)R(±19.1°)with one of eight and one of six Ge atoms protruding upward respectively,that consistently describe the experimentally observed STM images both for single and multi domai n surface *** to the DFT based simulati ons both germa nene(2×2)and(√3×√3)R30°superstructures have a stretched lattice strain with respect to the ideal free-standing germa nene by 6.2%and 13.9%,***,numerous small domains separated by domain boundaries in the(√3×√3)R30°/Al(111)(√7×√7)R(±19.1°)germanenephase tend to reduce the surface energy and prevent the formation of extended single domains,in contrast to the(2×2)/Al(111)(3×3)***,our experimental results showed that the nucleation and growth of germa nene on Al(111)surface yield strong modifications of Alsurface even at room temperature(RT),which may be contributed to the formation of Al-Ge alloy due to Ge surface solid-states reactivitythat was ignored in recent *** is already evident from our present findings that the role of Al atoms in the formation of(3×3)and(√7×√7)R(±19.1°)germa nene phases is worthy to be carefully studied in the future,which could be an important knowledge for large-quantityfabrication of germane

关键词： germanene two-dimensional(2D)materials scanning tunneling microscopy density functional theory aluminum

Microstructure, Mechanical Properties, Corrosion Behavior and Biocompatibility of As-Extruded Biodegradable Mg–3Sn–1Zn–0.5Mn Alloy

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Journal of Materials Science & Technology 2016年第9期32卷 874-882页

作者： Lida Hou Zhen Li Hong Zhao Yu Pan sergey Pavlinich Xiwei Liu Xinlin Li Yufeng Zheng Li Li Center for Biomedical Materials and Engineering Harbin Engineering UniversityHarbin 150001China Institute of Materials Processing and Intelligent Manufacturing Harbin Engineering UniversityHarbin 150001China Hospital of Heilongjiang Province Harbin 150001China Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China

The microstructure evolution and mechanical properties of biodegradable Mg-3Sn-1Zn-0.5Mn alloys were investigated by the optical microscopy, X-ray diffractometer and a universal material testing machine. The corrosion and degradation behaviors were studied by potentiodynamic polarization method and immersion test in a simulated body fluid （SBF）. It was found that the as-extruded Mg-3Sn-1Zn-0.5Mn alloy has the fine equiaxed grains which underwent complete dynamic recrystallization during the hot extrusion process, with the second phase particles of Mg2Sn precipitated on the grain boundaries and inside the grains. The tensile strength and elongation of as-extruded Mg-3Sn-1Zn-0.5Mn alloys were 244 ± 3.7 MPa and 19.3% ± 1.7%, respectively. The potentiodynamic polarization curves in SBF solution indicated the better corrosion resistance of the as-extruded Mg-3Sn-1Zn-0.5Mn alloy in the SBF solution. Immersion test in the SBF solution for 720 h revealed that the corrosion rate of as-extruded Mg-3Sn-1Zn-0.5Mn alloy was nearly 4±0.33 ram/year. The hemolysis rate of as-extruded Mg-3Sn-1Zn-0.5Mn alloy was lower than the safe value of 5% according to ISO 10993-4. As-extruded Mg-3Sn- 1Zn-0.5Mn alloy showed good biocompatibility after being implanted into the dorsal muscle and the femoral shaft of the rabbit, and no abnormalities were found after short-term implantation. It was revealed that the as-extruded Mg-3Sn-1Zn-0.5Mn alloy is a promising material for biodegradable implants, which possesses an interesting combination of preferred mechanical properties, better corrosion resistance and biocompatibility.

关键词： Biodegradable magnesium alloy Extrusion Mechanical property Corrosion Biocompatibility

Experimental study on mechanical and frost heave behaviors of silty clay improved by polyvinyl alcohol and polypropylene fiber

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Research in Cold and Arid Regions 2023年第2期15卷 57-65页

作者： JianKun Liu sergey Tsaybel XiaoQiang Liu Li Liu XiaoKang Li Xu Li School of Civil Engineering Sun Yat-sen UniversityZhuhaiGuangdong 519082China Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

Silty clay is widely used as subgrade filler in cold regions,which suffer from frost heave in winter and mud pumping in *** this study,polyvinyl alcohol(PVA)and polypropylene(PP)fiber were used to improve the mechanical and frost heave behavior of silty clay in cold regions,and the direct shear test and one-dimensional frost heave test were employed in studying improvement ***,improvement mechanisms of PVA and PP fiber were analyzed based on test *** main findings are as follows.(1)Both PP and PVA can heighten the strength of silty clay and suppress frost heave,but the PVA solution has a more decisive influence on improving mechanical properties than PP fiber.(2)The improvement mechanism of the PVA solution is *** improvement effect of 2%PVA solution is the best,which can increase the shear strength by approximately 40%–60%at different stress levels and decrease the frost heave ratio from 0.89%to 0.16%at optimal water content.(3)For 2%PVA improved samples,0.25%PP fiber can further increase soil cohesion by approximately 20–30 kPa at different stress levels and further decrease the frost heave ratio from 0.16%to 0.07%at optimal water *** improvement effect is neglectable when the PP fiber content exceeds 0.25%.Overall,2%PVA with 0.25%PP fiber is the optimum combination to improve silty clay in cold regions.

关键词： Frost heave Improved soil Subgrade fillers Polyvinyl alcohol Polypropylene fiber

Chemical composition of natural waters at Broknes Peninsula, Larsemann Hills, Antarctica

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Advances in Polar Science 2023年第4期34卷 318-339页

作者： sergey KAKAREKA Tamara KUKHARCHYK Yury GIGINYAK Peter KURMAN Institute for Nature Management National Academy of Sciences of BelarusLaboratory of Transboundary PollutionMinsk 220076Belarus Scientific and Practical Center for Bioresources National Academy of Sciences of BelarusMinsk 220072Belarus Institute of Bioorganic Chemistry National Academy of Sciences of BelarusLaboratory of Physical and Chemical MethodsMinsk 220141Belarus

The article contributes to the study of the content of major and trace elements in various types of natural waters of the Broknes Peninsula,Larsemann Hills,Antarctica collected in January–February 2014 and 2020 during the 7th and 12th Belarusian Antarctic *** of old(13 samples)and newly fallen snow(5),lakes(23)and groundwater(8)were *** content of 25 major and trace elements was determined using ICP-MS method,main anions was determined by titrimetric and turbidimetric *** similarity chemical composition of snow,groundwater and lake waters in spite of differences in the content of major ions and trace elements has been *** influence of marine salts on natural waters are analyzed,and their accumulation in lake waters especially in the endorheic small and shallow lakes in spite of ultra-oligotrophic atmospheric precipitates are *** spatial heterogeneity of groundwater and temporal and spatial heterogeneity of lake waters have been *** results are important for understanding the variabilities of major and trace elements content in snow,groundwater and lake waters,and their relationship,as well as for identifying trends in their change,taking into account anthropogenic loads in the region and climate change.

关键词： Antarctica snow groundwater lake major element trace element

Evaluation of DNA Damage in the Marine Mussel Crenomytilus grayanus as a Genotoxic Biomarker of Pollution

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Journal of Ocean University of China 2019年第1期18卷 159-164页

作者： SLOBODSKOVA Valentina V. ZHURAVEL Elena V. KUKLA sergey P. CHELOMIN Victor P. Laboratory of Marine Ecotoxicology V.I.Ilichev Pacific Oceanological Institute Far Eastern Branch Russian Academy of Sciences School of Natural Sciences Far Eastern Federal University

Marine pollution affects all life processes in aquatic organisms. The genotoxic effect of pollution on the mussel Crenomytilus grayanus was assessed. Bivalves were collected from the ‘clean'(Vostochnaya Cove) and polluted(Nakhodka Bay) areas in the Peter the Great Bay. The degree of DNA damage in C. grayanus was determined by alkaline comet assay as mean percentage of DNA in tail, and the genetic damage index was calculated. Our results indicate that almost one-third of DNA in cells of gills and digestive gland of C. grayanus inhabiting the Nakhodka Bay had destructive changes compared to the individuals of this species from the Vostochnaya Cove. This study has shown that chronic pollution of the aquatic environment causes destructive changes to DNA in gill and digestive gland cells of C. grayanus.

关键词： genotoxicity DNA comet assay Crenomytilus grayanus pollution

Modeling potential scenarios of the Tangjiashan Lake outburst and risk assessment in the downstream valley

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Frontiers of Earth Science 2017年第3期11卷 579-591页

作者： Vera KIDYAEVA sergey CHERNOMORETS Inna KRYLENKO Fangqiang WEI Dmitry PETRAKOV Pengcheng SU Hongjuan YANG Junnan XIONG Lomonosov Moscow State University Faculty of Geography 119991 Moscow Russia Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 China

This research is devoted to Taniashan Lake, a quake landslide-dammed lake, situated in Sichuan Pro- vince, China, which was formed by a landslide triggered by the Wenchuan Earthquake on 12 May 2008. A STREAM_2D two-dimensional hydrodynamic model of Russia was applied to simulate the process of two flood scenarios： 1, lake dam outbreak, and 2, dam overtopping. An artificial dam outbreak was made after the earthquake to lower the water level of the lake in 2008, which led to a great flood with a maximum water discharge of more than 6400 m3/s. The negative impact of the flood was reduced by a timely evacuation of the population. Flood hazards still remain in the event of new landslides into the lake and lake dam overtopping （Scenario 2）, in which case a maximum water discharge at the dam crest would reach 5000 m3/s, placing the population of Shabacun and Shilingzi villages in the zone of flood impact.

关键词： Tangjiashan Lake landslide-dammed lakeoutburst hydrodynamic modeling risk assessment

Transcriptome and Metabolic Profiling Provides Insigh into Betalain Biosynthesis and Evolution in Mirabilis jalapa

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Molecular Plant 2018年第1期11卷 189-204页

作者： Guy Polturak Uwe Heinig Noam Grossman Maor Battat Dena Leshkowitz sergey Malitsky liana Rogachev~ and Asaph Aharoni Department of Plant and Environmental Sciences Weizmann Institute of Science 234 Herzl Street Rehovot 7610001 Israel Bioinformatics Unit Life Sciences Core Facilities Weizmann Institute of Science 234 Herzl Street Rehovot 7610001 Israel

Betalains are tyrosine-derived pigments that occur solely in one plant order, the Caryophyllales, where they largely replace the anthocyanins in a mutually exclusive manner. In this study, we conducted multi-species transcriptome and metabolic profiling in Mirabilisjalapa and additional betalain-producing species to identify candidate genes possibly involved in betalain biosynthesis. Among the candidates identified, betalainrelated ytochrome P450 and glucosyltransferase-type genes, which catalyze tyrosine hydroxylation or （hydroxy）cinnamoyl-glucose formation, respectively, were further functionally characterized. We detected the expression of genes in the flavonoid/anthocyanin biosynthetic pathways as well as their metabolite intermediates in betalain-accumulating M. jalapa flowers, and found that the anthocyanin-related gene ANTHOCYANIDIN SYNTHASE （MjANS） is highly expressed in the betalain-accumulating petals. However, it appears that MjANS contains a significant deletion in a region spanning the corresponding enzyme active site. These findings provide novel insights into betalain biosynthesis and a possible explanation for how anthocyanins have been lost in this plant species. Our study also implies a complex, non-uniform history for the loss of anthocyanin production across betalain producers, previously assumed to be strictly due to diminished expression of anthocyanin-related genes.

关键词： betalain anthocyanin caryophyllales plant pigment biosynthesis secondary metabolism

Characterization of irradiated nails in terms of depolarizing Mueller matrix decompositions

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Frontiers of Optoelectronics 2017年第3期10卷 308-316页

作者： sergey SAVENKOV Alexander V. PRIEZZHEV Yevgen OBEREMOK sergey SHOLOM Ivan KOLOMIETS Taras Shevchenko National University of Kyiv Faculty of Radio Physics Electronics and Computer Systems Vladimirskaya str. 64 01033 Kiev Ukraine Lomonosov Moscow State University Department of Physics and Intemational Laser Center Vorobiovy Gory 119992 Moscow Russia Oklahoma State University Department of Physics 145 Physical Sciences Building Stillwater Oklahoma 74078 USA

Mueller matrices were measured for natural （or reference） samples of human nails and samples irradiated by a 2 Gy ionizing radiation dose. The elements of the total Mueller matrix as a function of scattering angle were measured in backscattering mode at a wavelength of 632.8 nm. Several types of depolarizing Mueller matrix decompositions, namely, Ossikovsky, Williams, and Chipman, were calculated as a function of scattering angle for each nail sample. A comparative analysis of the sensitivity of the Mueller matrix decompositions in relation to the problem of emergency dose assessment in nails was performed.

关键词： Mueller matrix depolarization human nails,ionizing radiation dose scattering

Melt Pockets in Garnet Megacrysts from Cenozoic Alkali Basalts of the Shavaryn Tsaram Vicinity,Mongolia

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Acta Geologica Sinica(English Edition) 2022年第1期96卷 111-122页

作者： Anna ASEEVA Oleg AVCHENKO Alexander KARABTSOV Alexander CHASHCHIN sergey VYSOTSKIY Victoria YAKOVENKO Natalia ZARUBINA Natalia KHARITONOVA Far East Geological Institute Russian Academy of SciencesVladivostok 690022Russia Far Eastern Federal University Natural Science SchoolVladivostok 690022Russia Lomonosov Moscow State University Geological DepartmentMoscow 119991Russia

Garnet megacryst with a multiphase inclusion from intraplate alkali basalts of the Shavaryn Tsaram(Tariat,Mongolia)was the object of the *** unusual aggregate consists of porous glass,Ti-rich biotite,orthopyroxene,spinel,clinopyroxene,olivine,and *** TWQ 2.32 thermodynamic simulation of this system revealed a few intervals of *** and temperature adjustment reflected in the paragenetic minerals of the melt *** capture of already crystallised garnet megacryst was at P=0.8-1 GPa and T=1120-1160℃.Mineral crystallisation inside the melt pocket,accompanied by external inputs,occurred at P=0.75-0.95 GPa;T=790-1120℃.Symplectite assemblage formed in the garnet megacryst due to decomposition at(P=0.55-0.7 GPa;T=850-930℃).The study of the oxygen isotope content in primary garnet and biotite of the melt pocket showed that the δ^(18)O_(VSMOW) values are the same and correspond to that of typical mantle ***,the chemical and microcomponent composition of the melt pocket minerals reveals a material that differs from basalts and ***,it has been revealed that the multiphase inclusion in the garnet megacryst formed not only on account of the garnet’s substance,but also due to the entrapped material of the Earth’s interior.

关键词： megacrysts garnet alkali basalts WinTWQ 2.32