The present paper is devoted to an overview on fossil Coleoptera studied from Inner Mongolia, Daohugou (Middle Jurassic, Jiulongshan Formation) and Liaoning (Upper Jurassic-Lower Cretaceous, Yixian Formation) depo...The present paper is devoted to an overview on fossil Coleoptera studied from Inner Mongolia, Daohugou (Middle Jurassic, Jiulongshan Formation) and Liaoning (Upper Jurassic-Lower Cretaceous, Yixian Formation) deposited in Chinese collections. As a result, species of the tribe Sperchopsini and Hydrophilini from Hydrophilidae, families and subfamilies Silphidae, Syndesinae from Lucanidae, Pleocomidae, Trogidae, Trogissitidae, Pyrochroidae, Diaperinae from Tenebrionidae, and Cerambycidae were first registered in the Mesozoic and some families were defined as new. It was shown that many superfamilies represented in the Recent Fauna were formed within the Middle Jurassic and Lower Cretaceous. The materials examined confirm the hypothesis that Cucujiformian beetles are a younger group than other infraordera of Polyphaga (Staphyliniformia and Elateriformia) and, therefore, they appeared in the fossil record only in the late Mesozoic. It was shown and confirmed that most superfamilies appeared in the fossil records before Cucujoidea. The synonymy of Notocupes Ponomarenko, 1964; Sinocupes Lin, 1976, syn. nov.; Amblomma Tan, Ren et Liu 2005, syn. nov.; Euryomma Tan, Ren et Shih, 2006, syn. nov., non Stein, 1899 and Ovatocupes Tan et Ren, 2006, syn. nov.; synonymy of Tetraphalerus Waterhouse, 1901 and Odontomma Tan, Ren et Ge 2006, syn. nov.; and synonymy of Priacmopsis Ponomarenko, 1966 and Latocupes Tan et Ren, 2006, syn. nov. are proposed. Sinorhombocoleus papposus Tan et Ren, 2009 is transferred from the family Rhombocoleidae to Schizophoridae. Cervicatinius complanus Tan, Ren et Shih, 2007 and Forticatinius elegans Tan, Ren et Shih, 2007 are transferred from the family Catiniidae (suborder Archostemata) to superfamily Cleroidea (suborder Polyphaga: first among the family Peltidae and second as a closely related group to the latter family). The family Parandrexidae is transferred from the superfamily Cucujoidea to Cleroidea. The ecological circumstances of the past ecosystems and hypotheses of historical development of the order Coleoptera are discussed. The age of faunas examined is considered. The list of the taxa described from Daohugou and Liaonlng is compiled.展开更多
In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment o...In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO_3 at 80 °C followed by NH_4OH titration for Mg(OH)_2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using(Mg(NO_3)_2á6H_2O) which were obtained from serpentinite, NH4 OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy(SEM) and transmission electron microscopy(TEM), X-ray phase analysis(XRD), and inductively coupled plasma optical emission spectroscopy(ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)_2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)_2 are 30–265 nm length or width.展开更多
In dielectrics and semiconductors, a plasma model of the generation and slip of dislocations is considered, where under shock loads in a generalized space of rectangular pulses an alternating field forms a distributio...In dielectrics and semiconductors, a plasma model of the generation and slip of dislocations is considered, where under shock loads in a generalized space of rectangular pulses an alternating field forms a distribution of pairs of photoelectrons and cations;these electrons with velocities <em>V<sub>e</sub></em> create <em>δ</em>-collisions with cold plasma from free electrons and holes with masses <em>m<sub>e</sub></em> and <em>m<sub>h</sub></em> (<em>m<sub>h</sub></em> <span style="white-space:normal;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">≫</span></span> </span></span><em>m<sub>e</sub></em>), they emit and absorb longitudinal electron plasma waves whose phase velocities <em>w<sub>pw</sub></em> / <em>k<sub>pw</sub></em> are close to or are equal to the velocities <em>V<sub>e</sub></em>, while the frequencies <em>w<sub>pw</sub></em> and wave numbers <em>k<sub>pw</sub></em> of the wave packet of plasma waves are complex, the short-wave components <img src="Edit_3da65014-7fd8-4799-bcf1-02d90028f4e0.bmp" alt="" /> of this wave packet at <em>k<sub>pw</sub></em> <span style="white-space:normal;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span> </span><em>a<sub>e </sub></em><span style="white-space:nowrap;">≫ </span>1 (<em>a<sub>e</sub></em> -Debye screening radius) decay in the core linear defect, and its long-wavelength components <img src="Edit_4481889b-5097-4d26-9019-b0322f5ff8d0.bmp" alt="" /> propagate in the region of the medium surrounding the core of the defect at <em>k<sub>pw</sub></em> <span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span> <em>a<sub>e</sub></em> <span style="white-space:nowrap;"><<span style="white-space:nowrap;"><span style="white-space:nowrap;">≅</span></span></span> 1. When a defect is generated, the distribution of cations under the influence of the internal Coulomb field shifts to the region of the first peak (protrusion) of the electron plasma wave, thereby forming a vacancy valley. When sliding under the influence of an external electric field, a cationic plasma wave consisting of a vacancy valley and two cationic protrusions moves against the background of an additional potential relief created by an electron plasma wave near the core of the defect. It has been shown that <em>δ</em>-collisions create flows of dynamic large-scale correlations of plasma fluctuations in the form of asymptotics of different-time correlators of density and potential fluctuations as <em>t</em> → +∞.展开更多
A relationship between thermal effects and relaxation of the high-frequency shear modulus upon heat treatment of bulk Zr48(Cu5/6Ag1/6)44Al8 metallic glass is found.This relationship is attributed to the relaxation of ...A relationship between thermal effects and relaxation of the high-frequency shear modulus upon heat treatment of bulk Zr48(Cu5/6Ag1/6)44Al8 metallic glass is found.This relationship is attributed to the relaxation of a interstitial-type defect system frozen-in from the melt upon glass production.Calorimetric data show that thermal effects occurring on heating include heat release below the glass transition temperature,heat absorption above it and heat release caused by crystallization.The equation derived within the Interstitialcy theory can be used to calculate the shear modulus relaxation using the calorimetric data.The obtained results are used to trace the defect concentration as functions of temperature and thermal prehistory.展开更多
Three experiments were set up to evaluate conditions for the high-temperature decomposition of celadonite from a banded iron formation in an alumina-free system and identify its decomposition products. It was estimate...Three experiments were set up to evaluate conditions for the high-temperature decomposition of celadonite from a banded iron formation in an alumina-free system and identify its decomposition products. It was estimated that at 650 and 750 °C, with a Ni Ni O buffer and pressure of 3 kbar, celadonite completely decomposes and the decomposition products were tetraferribiotite, magnetite and quartz. Under more oxidizing conditions(hematite-magnetite buffer instead of Ni Ni O), ferrous potassium feldspar sanidine forms instead of magnetite.During the celadonite decomposition in oxidizing conditions more magnesian and aluminous tetraferribiotite,along with ferrous sanidine, are formed than at reducing conditions.展开更多
Nanocomposites on the base of thin films SnO_2 with additives of metal oxides such as SiO_2,ZrO_2,MnO_2 and others,were prepared by reactive ion-beam sputtering of metal target in the ambient of O_2+At,and then therma...Nanocomposites on the base of thin films SnO_2 with additives of metal oxides such as SiO_2,ZrO_2,MnO_2 and others,were prepared by reactive ion-beam sputtering of metal target in the ambient of O_2+At,and then thermal treated at 500℃.Atomic composition and morphology of thin film nanocomposites were investigated.Electrical properties and gas sensitivity of nanocomposites were studied.It Was determined that the grain size of polycrystals depends on the film composition and can run down to 10 nm.It was found that temperature of maximal gas sensitivity of the films depends on their composition as well and it can be decreased by 100℃~150℃lower than temperature of maximal sensitivity of undoped films SnO_2.展开更多
A 3D model of deep crustal structure of the Archaean Karelia Craton and late Palaeoproterozoic Svecofennian Accretionary Orogen including the boundary zone is presented.The model is based on the combination of data fr...A 3D model of deep crustal structure of the Archaean Karelia Craton and late Palaeoproterozoic Svecofennian Accretionary Orogen including the boundary zone is presented.The model is based on the combination of data from geological mapping and reflection seismic studies,along profiles 1-EU,4 B,FIRE-1-2 a-2 and FIRE-3-3 a,and uses results of magnetotelluric soundings in southern Finland and northern Karelia.A seismogeological model of the crust and crust-mantle boundary is compared with a model of subhorizontal velocity-density layering of the crust.The TTG-type crust of the Palaeoarchaean and Mesoarchaean microcontinents within the Karelia Craton and the Belomorian Province are separated by gently dipping greenstone belts,at least some of which are palaeosutures.The structure of the crust was determined mainly by Palaeoproterozoic tectonism in the intracontinental settings modified by a strong collisional compression at the end of the Palaeoproterozoic.New insights into structure,origin and evolution of the Svecofennian Orogen are provided.The accretionary complex is characterized by inclined tectonic layering:the tectonic sheets,~15 km thick,are composed of volcanic-sedimentary rocks,including electro-conductive graphite-bearing sedimentary rocks,and electro-resistive granitoids,which plunge monotonously and consecutively eastward.Upon reaching the level of the lower crust,the tectonic sheets of the accretionary complex lose their distinct outlines.In the seismic reflection pattern they are replaced by a uniform acoustically translucent medium,where separate sheets can only be traced fragmentarily.The crust-mantle boundary bears a diffuse character:the transition from crust to mantle is recorded by the disappearance of the vaguely drawn boundaries of the tectonic sheets and in the gradual transition of acoustically homogeneous and translucent lower crust into transparent mantle.Under the effect of endogenic heat flow,the accretionary complex underwent high-temperature metamorphism and partial melting.Blurring of the rock contacts,which in the initial state created contrasts of acoustic impedance,was caused by partial melting and mixing of melts.The 3 D model is used as a starting point for the evolutionary model of the Svecofennian Accretionary Orogen and for determination of its place in the history of the Palaeoproterozoic Lauro-Russian intracontinental orogeny,which encompassed a predominant part of the territory of Lauroscandia,a palaeocontinent combining North American and East European cratons.The model includes three stages in the evolution of the Lauro-Russian Orogen(-2.5,2.2-2.1 and 1.95-1.87 Ga).The main feature of the Palaeoproterozoic evolution of the accretionary Svecofennian Orogen and Lauroscandia as a whole lay in the causal link with evolution of a superplume,which initiated plate-tectonic events.The Svecofennian-Pre-Labradorian palaeo-ocean originated in the superplume axial zone;the accretionary orogens were formed along both continental margins due to closure of the palaeo-ocean.展开更多
Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have ant...Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have antioxidant activity,are of interest.We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions.Here,we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline(BHDQ)for carbon tetrachloride(CCl4)-induced liver injury in rats.Results suggested that BHDQ normalized the alanine aminotransferase,aspartate aminotransferase,and gamma-glutamyl transpeptidase in serum.We also observed an improvement in liver tissue morphology related to BHDQ.Animals with CCl4-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl4-induced liver injury.BHDQ promoted activation changes in superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase,and glutathione transferase on control values in animals with CCl4-induced liver injury.BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors.Therefore,the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue,through antioxidation.展开更多
The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has...The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has not yet been studied. This work is aimed at finding differences in the bone morphology of Amur and Dione’s ratsnakes and the criteria for their identification. The variety of bone morphology depends on several parameters. First, these are species differences which determine the systematic position of the animal. Second, it is individual varia bility.Third, these are progressive changes in the vertebrae morphology along the vertebral column from the first vertebra to the last. Fourth, it is age-related variability. 20 skeletonised specimens: 12 specimens of Elaphe dione and 8 specimens of Elaphe schrenckii were used to define diagnostic osteological characters. The bones of the two studied species are very similar and their variability overlaps. However, differences and identification criteria were found for 13 skull bones:nasal, frontal, parietal, supraoccipital, maxilla, quadrate,palatine, pterygoid, ectopterygoid, basiparasphenoid,basioccipital, dentary and the compound bone. In addition, the variability and differences of the cervical,trunk, cloacal, and caudal vertebrae were examined.展开更多
In this paper, it is proved the ability of quantity reconstruction, amplitudes and coordinates of metallic strip local scattering sources from the backscattering pattern. They are performed as the results of numerical...In this paper, it is proved the ability of quantity reconstruction, amplitudes and coordinates of metallic strip local scattering sources from the backscattering pattern. They are performed as the results of numerical solution for the infinite perfect conducting strip in case of E-polarization of the incident plane electromagnetic wave. In this case it is necessary to fulfill the following conditions. The local sources amplitudes should be the same order, in transverse and longitudinal directions the local sources should be separated into distances more than apparatus resolution, and the object maximum size does not have to be more than approximately 50λ. It was shown the limit and ability of the further development of the offered method.展开更多
A method for investigating the optical properties of human tissues is suggested.The method is based on the measurement of Cherenkov radiation produced by relativistic electrons passing through the tissue.Monte-Carlo s...A method for investigating the optical properties of human tissues is suggested.The method is based on the measurement of Cherenkov radiation produced by relativistic electrons passing through the tissue.Monte-Carlo simulation of visible photon emission and propagation is carried out taking into account multiple electron and photon scattering processes.Sensitivity of the Cherenkov radiation to the optical characteristics of human tissues is demonstrated.展开更多
The field emission current from a carbon fiber is considered. As a model of emission of an elementary carbon tube, tunnel ionization of an electron from a short-range potential is taken. The exact solution for the wav...The field emission current from a carbon fiber is considered. As a model of emission of an elementary carbon tube, tunnel ionization of an electron from a short-range potential is taken. The exact solution for the wave function in such a model allows obtaining an asymptotic expression for electron current. A computer model of transverse distribution of emission current of a carbon fiber is built on the basis of the Monte Carlo method that allows taking into account the random character of distribution of local emitter sources and the distribution of gains of an electric field in carbon nanotubes.展开更多
基金supported by the National Natural Science Foundation of China (No.40872022)Nature Science Foundation of Beijing(No. 5082002)the PHR(IHLB) Project of Beijing Municipal Commission of Education and the Programme of the Presidium of the Russian Academy of Sciences"Origin and Evolution of Biosphere"and Russian Foundation of Basic Research(grants 07- 04-92105-GFEN_a and 09-04-00789-a)
文摘The present paper is devoted to an overview on fossil Coleoptera studied from Inner Mongolia, Daohugou (Middle Jurassic, Jiulongshan Formation) and Liaoning (Upper Jurassic-Lower Cretaceous, Yixian Formation) deposited in Chinese collections. As a result, species of the tribe Sperchopsini and Hydrophilini from Hydrophilidae, families and subfamilies Silphidae, Syndesinae from Lucanidae, Pleocomidae, Trogidae, Trogissitidae, Pyrochroidae, Diaperinae from Tenebrionidae, and Cerambycidae were first registered in the Mesozoic and some families were defined as new. It was shown that many superfamilies represented in the Recent Fauna were formed within the Middle Jurassic and Lower Cretaceous. The materials examined confirm the hypothesis that Cucujiformian beetles are a younger group than other infraordera of Polyphaga (Staphyliniformia and Elateriformia) and, therefore, they appeared in the fossil record only in the late Mesozoic. It was shown and confirmed that most superfamilies appeared in the fossil records before Cucujoidea. The synonymy of Notocupes Ponomarenko, 1964; Sinocupes Lin, 1976, syn. nov.; Amblomma Tan, Ren et Liu 2005, syn. nov.; Euryomma Tan, Ren et Shih, 2006, syn. nov., non Stein, 1899 and Ovatocupes Tan et Ren, 2006, syn. nov.; synonymy of Tetraphalerus Waterhouse, 1901 and Odontomma Tan, Ren et Ge 2006, syn. nov.; and synonymy of Priacmopsis Ponomarenko, 1966 and Latocupes Tan et Ren, 2006, syn. nov. are proposed. Sinorhombocoleus papposus Tan et Ren, 2009 is transferred from the family Rhombocoleidae to Schizophoridae. Cervicatinius complanus Tan, Ren et Shih, 2007 and Forticatinius elegans Tan, Ren et Shih, 2007 are transferred from the family Catiniidae (suborder Archostemata) to superfamily Cleroidea (suborder Polyphaga: first among the family Peltidae and second as a closely related group to the latter family). The family Parandrexidae is transferred from the superfamily Cucujoidea to Cleroidea. The ecological circumstances of the past ecosystems and hypotheses of historical development of the order Coleoptera are discussed. The age of faunas examined is considered. The list of the taxa described from Daohugou and Liaonlng is compiled.
基金the state on behalf of the Ministry of Education and Science of the Russian Federation of the Agreement (No. 14.577.21.0111 (22 September 2014))The unique identifier of the applied research (No. RFMEFI57714X0111)
文摘In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO_3 at 80 °C followed by NH_4OH titration for Mg(OH)_2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using(Mg(NO_3)_2á6H_2O) which were obtained from serpentinite, NH4 OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy(SEM) and transmission electron microscopy(TEM), X-ray phase analysis(XRD), and inductively coupled plasma optical emission spectroscopy(ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)_2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)_2 are 30–265 nm length or width.
文摘In dielectrics and semiconductors, a plasma model of the generation and slip of dislocations is considered, where under shock loads in a generalized space of rectangular pulses an alternating field forms a distribution of pairs of photoelectrons and cations;these electrons with velocities <em>V<sub>e</sub></em> create <em>δ</em>-collisions with cold plasma from free electrons and holes with masses <em>m<sub>e</sub></em> and <em>m<sub>h</sub></em> (<em>m<sub>h</sub></em> <span style="white-space:normal;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">≫</span></span> </span></span><em>m<sub>e</sub></em>), they emit and absorb longitudinal electron plasma waves whose phase velocities <em>w<sub>pw</sub></em> / <em>k<sub>pw</sub></em> are close to or are equal to the velocities <em>V<sub>e</sub></em>, while the frequencies <em>w<sub>pw</sub></em> and wave numbers <em>k<sub>pw</sub></em> of the wave packet of plasma waves are complex, the short-wave components <img src="Edit_3da65014-7fd8-4799-bcf1-02d90028f4e0.bmp" alt="" /> of this wave packet at <em>k<sub>pw</sub></em> <span style="white-space:normal;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span> </span><em>a<sub>e </sub></em><span style="white-space:nowrap;">≫ </span>1 (<em>a<sub>e</sub></em> -Debye screening radius) decay in the core linear defect, and its long-wavelength components <img src="Edit_4481889b-5097-4d26-9019-b0322f5ff8d0.bmp" alt="" /> propagate in the region of the medium surrounding the core of the defect at <em>k<sub>pw</sub></em> <span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span> <em>a<sub>e</sub></em> <span style="white-space:nowrap;"><<span style="white-space:nowrap;"><span style="white-space:nowrap;">≅</span></span></span> 1. When a defect is generated, the distribution of cations under the influence of the internal Coulomb field shifts to the region of the first peak (protrusion) of the electron plasma wave, thereby forming a vacancy valley. When sliding under the influence of an external electric field, a cationic plasma wave consisting of a vacancy valley and two cationic protrusions moves against the background of an additional potential relief created by an electron plasma wave near the core of the defect. It has been shown that <em>δ</em>-collisions create flows of dynamic large-scale correlations of plasma fluctuations in the form of asymptotics of different-time correlators of density and potential fluctuations as <em>t</em> → +∞.
基金the National Natural Science Foundation of China(Grant No.51971178)the Astronautics Supporting Technology Foundation of China(Grant No.2019-HT-XG)+2 种基金the Natural Science Foundation of Shaanxi Province,China(Grant No.2019JM-344)the Russian Science Foundation(Grant No.20-62-46003)the Fundamental Research Funds for the Central Universities,China(Grant Nos.3102019ghxm007 and 3102017JC01003).
文摘A relationship between thermal effects and relaxation of the high-frequency shear modulus upon heat treatment of bulk Zr48(Cu5/6Ag1/6)44Al8 metallic glass is found.This relationship is attributed to the relaxation of a interstitial-type defect system frozen-in from the melt upon glass production.Calorimetric data show that thermal effects occurring on heating include heat release below the glass transition temperature,heat absorption above it and heat release caused by crystallization.The equation derived within the Interstitialcy theory can be used to calculate the shear modulus relaxation using the calorimetric data.The obtained results are used to trace the defect concentration as functions of temperature and thermal prehistory.
文摘Three experiments were set up to evaluate conditions for the high-temperature decomposition of celadonite from a banded iron formation in an alumina-free system and identify its decomposition products. It was estimated that at 650 and 750 °C, with a Ni Ni O buffer and pressure of 3 kbar, celadonite completely decomposes and the decomposition products were tetraferribiotite, magnetite and quartz. Under more oxidizing conditions(hematite-magnetite buffer instead of Ni Ni O), ferrous potassium feldspar sanidine forms instead of magnetite.During the celadonite decomposition in oxidizing conditions more magnesian and aluminous tetraferribiotite,along with ferrous sanidine, are formed than at reducing conditions.
基金The work was supported by grant of Russian Foundation for Basic Research N 03-02-96453.
文摘Nanocomposites on the base of thin films SnO_2 with additives of metal oxides such as SiO_2,ZrO_2,MnO_2 and others,were prepared by reactive ion-beam sputtering of metal target in the ambient of O_2+At,and then thermal treated at 500℃.Atomic composition and morphology of thin film nanocomposites were investigated.Electrical properties and gas sensitivity of nanocomposites were studied.It Was determined that the grain size of polycrystals depends on the film composition and can run down to 10 nm.It was found that temperature of maximal gas sensitivity of the films depends on their composition as well and it can be decreased by 100℃~150℃lower than temperature of maximal sensitivity of undoped films SnO_2.
基金the RF state project(No.0135-2019-0036)partly supported by the project(No.0135-20180039)of the Program of the Presidium of the RAS“Fundamental problems of geological and geophysical study of lithospheric processes”the Russian Foundation for Basic Research for supporting project(No.19-05-00336)。
文摘A 3D model of deep crustal structure of the Archaean Karelia Craton and late Palaeoproterozoic Svecofennian Accretionary Orogen including the boundary zone is presented.The model is based on the combination of data from geological mapping and reflection seismic studies,along profiles 1-EU,4 B,FIRE-1-2 a-2 and FIRE-3-3 a,and uses results of magnetotelluric soundings in southern Finland and northern Karelia.A seismogeological model of the crust and crust-mantle boundary is compared with a model of subhorizontal velocity-density layering of the crust.The TTG-type crust of the Palaeoarchaean and Mesoarchaean microcontinents within the Karelia Craton and the Belomorian Province are separated by gently dipping greenstone belts,at least some of which are palaeosutures.The structure of the crust was determined mainly by Palaeoproterozoic tectonism in the intracontinental settings modified by a strong collisional compression at the end of the Palaeoproterozoic.New insights into structure,origin and evolution of the Svecofennian Orogen are provided.The accretionary complex is characterized by inclined tectonic layering:the tectonic sheets,~15 km thick,are composed of volcanic-sedimentary rocks,including electro-conductive graphite-bearing sedimentary rocks,and electro-resistive granitoids,which plunge monotonously and consecutively eastward.Upon reaching the level of the lower crust,the tectonic sheets of the accretionary complex lose their distinct outlines.In the seismic reflection pattern they are replaced by a uniform acoustically translucent medium,where separate sheets can only be traced fragmentarily.The crust-mantle boundary bears a diffuse character:the transition from crust to mantle is recorded by the disappearance of the vaguely drawn boundaries of the tectonic sheets and in the gradual transition of acoustically homogeneous and translucent lower crust into transparent mantle.Under the effect of endogenic heat flow,the accretionary complex underwent high-temperature metamorphism and partial melting.Blurring of the rock contacts,which in the initial state created contrasts of acoustic impedance,was caused by partial melting and mixing of melts.The 3 D model is used as a starting point for the evolutionary model of the Svecofennian Accretionary Orogen and for determination of its place in the history of the Palaeoproterozoic Lauro-Russian intracontinental orogeny,which encompassed a predominant part of the territory of Lauroscandia,a palaeocontinent combining North American and East European cratons.The model includes three stages in the evolution of the Lauro-Russian Orogen(-2.5,2.2-2.1 and 1.95-1.87 Ga).The main feature of the Palaeoproterozoic evolution of the accretionary Svecofennian Orogen and Lauroscandia as a whole lay in the causal link with evolution of a superplume,which initiated plate-tectonic events.The Svecofennian-Pre-Labradorian palaeo-ocean originated in the superplume axial zone;the accretionary orogens were formed along both continental margins due to closure of the palaeo-ocean.
基金supported by the Russian Foundation for Basic Research (Grant No. 20-04-00526А)
文摘Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have antioxidant activity,are of interest.We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions.Here,we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline(BHDQ)for carbon tetrachloride(CCl4)-induced liver injury in rats.Results suggested that BHDQ normalized the alanine aminotransferase,aspartate aminotransferase,and gamma-glutamyl transpeptidase in serum.We also observed an improvement in liver tissue morphology related to BHDQ.Animals with CCl4-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl4-induced liver injury.BHDQ promoted activation changes in superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase,and glutathione transferase on control values in animals with CCl4-induced liver injury.BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors.Therefore,the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue,through antioxidation.
文摘The taxonomic identification of Quaternary remains requires a comparison of fossil bones with the skeletons of existing taxa based on the morphological criteria. However, the osteology of most modern snake species has not yet been studied. This work is aimed at finding differences in the bone morphology of Amur and Dione’s ratsnakes and the criteria for their identification. The variety of bone morphology depends on several parameters. First, these are species differences which determine the systematic position of the animal. Second, it is individual varia bility.Third, these are progressive changes in the vertebrae morphology along the vertebral column from the first vertebra to the last. Fourth, it is age-related variability. 20 skeletonised specimens: 12 specimens of Elaphe dione and 8 specimens of Elaphe schrenckii were used to define diagnostic osteological characters. The bones of the two studied species are very similar and their variability overlaps. However, differences and identification criteria were found for 13 skull bones:nasal, frontal, parietal, supraoccipital, maxilla, quadrate,palatine, pterygoid, ectopterygoid, basiparasphenoid,basioccipital, dentary and the compound bone. In addition, the variability and differences of the cervical,trunk, cloacal, and caudal vertebrae were examined.
文摘In this paper, it is proved the ability of quantity reconstruction, amplitudes and coordinates of metallic strip local scattering sources from the backscattering pattern. They are performed as the results of numerical solution for the infinite perfect conducting strip in case of E-polarization of the incident plane electromagnetic wave. In this case it is necessary to fulfill the following conditions. The local sources amplitudes should be the same order, in transverse and longitudinal directions the local sources should be separated into distances more than apparatus resolution, and the object maximum size does not have to be more than approximately 50λ. It was shown the limit and ability of the further development of the offered method.
文摘A method for investigating the optical properties of human tissues is suggested.The method is based on the measurement of Cherenkov radiation produced by relativistic electrons passing through the tissue.Monte-Carlo simulation of visible photon emission and propagation is carried out taking into account multiple electron and photon scattering processes.Sensitivity of the Cherenkov radiation to the optical characteristics of human tissues is demonstrated.
文摘The field emission current from a carbon fiber is considered. As a model of emission of an elementary carbon tube, tunnel ionization of an electron from a short-range potential is taken. The exact solution for the wave function in such a model allows obtaining an asymptotic expression for electron current. A computer model of transverse distribution of emission current of a carbon fiber is built on the basis of the Monte Carlo method that allows taking into account the random character of distribution of local emitter sources and the distribution of gains of an electric field in carbon nanotubes.