The studies on the structure and physical properties of the Earths interior done by Chinese geophysicists from 1999 to 2002 were reviewed in this paper. It includes several research areas: the structure of the Earths ...The studies on the structure and physical properties of the Earths interior done by Chinese geophysicists from 1999 to 2002 were reviewed in this paper. It includes several research areas: the structure of the Earths interiors using seismic tomography, anisotropy of the upper mantle in China and its adjacent areas, quality factor Qb for S waves, subduction zone, mantle discontinuities, physical properties of Earths materials and others. The review concerns mainly the contents, the methods and the results of the studies. It can be seen that new progress in the study on the structure and physical properties of the Earths interior has been made in the last 4 years in China. It is shown on three aspects: advancement made on some preexistent areas; pioneering on some new fields and new methods adopted.展开更多
The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for unders...The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.展开更多
Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area o...Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic continent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the “GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Network (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed information on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains;and more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data obtained, local and regional signals associated with ice movements were recorded together with a significant number of teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarctica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.展开更多
Tritium （3^H） in excess of the atmospheric values was found at volcanic Lakes Pavin （France）, Laacher （Germany） and Nemrut （Turkey）, as well as Kilauea Volcano at Hawaii （USA） and other volcanoes. Because 3^...Tritium （3^H） in excess of the atmospheric values was found at volcanic Lakes Pavin （France）, Laacher （Germany） and Nemrut （Turkey）, as well as Kilauea Volcano at Hawaii （USA） and other volcanoes. Because 3^H has a short half-life of 12.3 years, the tritium and the resulting 3^He must have formed recently in the Earth. The result suggests that nuclear reactions may generate a significant amount of tritium in the interior of the Earth, although we have not yet learned what the reaction mechanism may be responsible. The nuclear reaction that can be responsible for tritium production in the Earth is probably a new research field in physics science. Nuclear reactions that generate tritium might be a source of ＂missing＂ energy （heat） in the interior of the Earth. Finding in-situ 3^H in the mantle may exhibit an alternative explanation of 3^He origin in the deep Earth.展开更多
Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the ...Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Young Earth before the Beginning of life on It;Internal Structure;“The 660-km Boundary” that we named Geomagma;Random Variations of Earth’s Rotational Speed on a daily basis;Origin of Moon;Expanding Earth;Internal Heating;Faint Young Sun paradox;Geocorona and Planetary Coronas;High-Energy Atmospheric Physics. WUM proposed principally different ways to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geomagma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field.展开更多
In this analysis, natural systems are posed to subsystemize in a manner facilitating both structured information/energy sharing and an entropy maximization process projecting a three-dimensional, spatial outcome. Nume...In this analysis, natural systems are posed to subsystemize in a manner facilitating both structured information/energy sharing and an entropy maximization process projecting a three-dimensional, spatial outcome. Numerical simulations were first carried out to determine whether n × n input-output matrices could, once entropy-maximized, project a three-dimensional Euclidean metric. Only 4 × 4 matrices could;a small proportion passed the test. Larger proportions passed when grouped random patterns on and within two- and three-dimensional forms were tested. The pattern of structural zonation within the earth was then tested in analogous fashion using spatial autocorrelation measures, and for three time periods: current, 95 million years b.p. and 200 million years b.p. All expected results were obtained;not only do the geometries of zonation project a three-dimensional structure as anticipated, but also do secondary statistical measures reveal levels of equilibrium among the zones in all three cases that are nearly total, distinguishing them from simulations that do not incorporate a varying-surface zone-width element.展开更多
We describe a method to perform a constrained lithospheric-scale inversion of satellite gravity gradient data.The a priori constraints include:i)data covariance matrix;ii)prior model covariance matrix including a mode...We describe a method to perform a constrained lithospheric-scale inversion of satellite gravity gradient data.The a priori constraints include:i)data covariance matrix;ii)prior model covariance matrix including a model for spatial variability of mantle heterogeneity.展开更多
Gravitation is one of the central forces playing an important role in formation of natural systems like galaxies and planets. Gravitational forces between particles of a gaseous cloud transform the cloud into spherica...Gravitation is one of the central forces playing an important role in formation of natural systems like galaxies and planets. Gravitational forces between particles of a gaseous cloud transform the cloud into spherical shells and disks of higher density during gravitational contraction. The density can reach that of a solid body. The theoretical model was tested to model the formation of a spiral galaxy and Saturn. The formations of a spiral galaxy and Saturn and its disk are simulated using a novel N-body self-gravitational model. It is demonstrated that the formation of the spirals of the galaxy and disk of the planet is the result of gravitational contraction of a slowly rotated particle cloud that has a shape of slightly deformed sphere for Saturn and ellipsoid for the spiral galaxy. For Saturn, the sphere was flattened by a coefficient of 0.8 along the axis of rotation. During the gravitational contraction, the major part of the cloud transformed into a planet and a minor part transformed into a disk. The thin structured disk is a result of the electromagnetic interaction in which the magnetic forces acting on charged particles of the cloud originate from the core of the planet.展开更多
In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK...In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).展开更多
Redox state is an important parameter in describing the thermodynamic state of the Earth’s interior.In contrast to the considerable efforts in early studies that have been expended on the redox state of Earth’s diff...Redox state is an important parameter in describing the thermodynamic state of the Earth’s interior.In contrast to the considerable efforts in early studies that have been expended on the redox state of Earth’s different spheres,much attention in the recent about 10 years has been paid to the effects of redox state on the various geodynamical aspects of Earth’s interior,or more commonly the redox geodynamics.Redox geodynamics plays a critical role in driving many processes that are involved in the accretion,differentiation,and re-shaping of the Earth from its early birth to modern periods and from its surface to the deep interior,including the structure,composition,nature,and evolution of the Earth and the significant effects on many important issues such as the climate change and habitability of the planet.This field has blossomed in these years around the chemical and physical properties of the Earth.In this review,a brief summary is provided for the basic concepts,general background and applications relevant to redox geodynamics.The redox state of the crust and mantle and its evolution have received particular attention in the past years,however,there are still fundamental issues remaining ambiguous,poorly quantified and/or even controversial.At the same time,significant progress has been made,mostly through experimental studies,on the redox geodynamics of the Earth’s interior,including(but are not limited to)the early oxidation of the shallow mantle,the rapid growth of the early continental crust,the redox freezing and melting associated with carbon or hydrogen,the transfer of metal elements and formation of ore deposits,the low seismic velocity and high attenuation of the asthenosphere,the aerobic processes around the core-mantle boundary,and the magma degassing and released gases.Redox geodynamics is becoming increasingly important in renewing the understanding of the chemical evolution,physical properties,and dynamical processes of the Earth.展开更多
Mean heat flows and heat losses of the Northern and Southern hemispheres are calculated using degree 12 spherical harmonic representation of the global heat flow field (Pollack et al., 1993). Mean heat flows and heat ...Mean heat flows and heat losses of the Northern and Southern hemispheres are calculated using degree 12 spherical harmonic representation of the global heat flow field (Pollack et al., 1993). Mean heat flows and heat losses of 0° hemisphere and 180° hemisphere, with median lines being 0° longitude and 180° longitude, are also calculated. The mean heat flow of the Southern Hemisphere is 99.3 mW·m -2, significantly higher than that of the Northern Hemisphere (74.0 mW·m -2). The mean heat flow of 0° hemisphere (94.1 mW·m -2) is also higher than the value of 180° hemisphere (79.3 mW·m -2). The mantle heat loss from the Southern Hemisphere is 22.1×10 12 W, as twice as that from the Northern Hemisphere ( 10.8×10 12 W). The 16.9×10 12 W mantle heat loss from 0° hemisphere is close to 16.0×10 12 W from 180° hemisphere. The hemispherical asymmetry of global heat loss is originated by the asymmetry of geographic distribution of continents and oceans. The asymmetric distribution of heat loss is a long-term phenomenon in the geological history.展开更多
The reaction of 3,6-di-(3-methyl-pyridin-2-yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3 · 6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone (L), and fo...The reaction of 3,6-di-(3-methyl-pyridin-2-yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3 · 6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2 (H2O)3] · NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2) nm, c = 1.4572(3) nm, α= 102.13(2)°, β= 99.81(3)°, γ= 91.10(3)°, Z = 2, V = 1113.6(7) nm3, μ = 2.123 mm?1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.展开更多
基金State Natural Science Foundation of China (40174023).
文摘The studies on the structure and physical properties of the Earths interior done by Chinese geophysicists from 1999 to 2002 were reviewed in this paper. It includes several research areas: the structure of the Earths interiors using seismic tomography, anisotropy of the upper mantle in China and its adjacent areas, quality factor Qb for S waves, subduction zone, mantle discontinuities, physical properties of Earths materials and others. The review concerns mainly the contents, the methods and the results of the studies. It can be seen that new progress in the study on the structure and physical properties of the Earths interior has been made in the last 4 years in China. It is shown on three aspects: advancement made on some preexistent areas; pioneering on some new fields and new methods adopted.
基金the National Natural Science Foundation of China (41574080 and U1530402).
文摘The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.
文摘Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic continent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the “GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Network (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed information on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains;and more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data obtained, local and regional signals associated with ice movements were recorded together with a significant number of teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarctica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.
基金supported by President Foundation of the China Institute of Atomic Energy (No.YZ-0704)
文摘Tritium （3^H） in excess of the atmospheric values was found at volcanic Lakes Pavin （France）, Laacher （Germany） and Nemrut （Turkey）, as well as Kilauea Volcano at Hawaii （USA） and other volcanoes. Because 3^H has a short half-life of 12.3 years, the tritium and the resulting 3^He must have formed recently in the Earth. The result suggests that nuclear reactions may generate a significant amount of tritium in the interior of the Earth, although we have not yet learned what the reaction mechanism may be responsible. The nuclear reaction that can be responsible for tritium production in the Earth is probably a new research field in physics science. Nuclear reactions that generate tritium might be a source of ＂missing＂ energy （heat） in the interior of the Earth. Finding in-situ 3^H in the mantle may exhibit an alternative explanation of 3^He origin in the deep Earth.
文摘Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Young Earth before the Beginning of life on It;Internal Structure;“The 660-km Boundary” that we named Geomagma;Random Variations of Earth’s Rotational Speed on a daily basis;Origin of Moon;Expanding Earth;Internal Heating;Faint Young Sun paradox;Geocorona and Planetary Coronas;High-Energy Atmospheric Physics. WUM proposed principally different ways to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geomagma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field.
文摘In this analysis, natural systems are posed to subsystemize in a manner facilitating both structured information/energy sharing and an entropy maximization process projecting a three-dimensional, spatial outcome. Numerical simulations were first carried out to determine whether n × n input-output matrices could, once entropy-maximized, project a three-dimensional Euclidean metric. Only 4 × 4 matrices could;a small proportion passed the test. Larger proportions passed when grouped random patterns on and within two- and three-dimensional forms were tested. The pattern of structural zonation within the earth was then tested in analogous fashion using spatial autocorrelation measures, and for three time periods: current, 95 million years b.p. and 200 million years b.p. All expected results were obtained;not only do the geometries of zonation project a three-dimensional structure as anticipated, but also do secondary statistical measures reveal levels of equilibrium among the zones in all three cases that are nearly total, distinguishing them from simulations that do not incorporate a varying-surface zone-width element.
基金supported by the European Space Agency’s Support to Science Element program,project"3D Earth:A Living Dynamics Planet"performed at The Centre for Earth Evolution and Dynamics,University of Oslo,funded by the Research Council of Norway through its center of excellence funding scheme,project 223272IPG SB RAS Project AAAAA16-116122810045-9
文摘We describe a method to perform a constrained lithospheric-scale inversion of satellite gravity gradient data.The a priori constraints include:i)data covariance matrix;ii)prior model covariance matrix including a model for spatial variability of mantle heterogeneity.
文摘Gravitation is one of the central forces playing an important role in formation of natural systems like galaxies and planets. Gravitational forces between particles of a gaseous cloud transform the cloud into spherical shells and disks of higher density during gravitational contraction. The density can reach that of a solid body. The theoretical model was tested to model the formation of a spiral galaxy and Saturn. The formations of a spiral galaxy and Saturn and its disk are simulated using a novel N-body self-gravitational model. It is demonstrated that the formation of the spirals of the galaxy and disk of the planet is the result of gravitational contraction of a slowly rotated particle cloud that has a shape of slightly deformed sphere for Saturn and ellipsoid for the spiral galaxy. For Saturn, the sphere was flattened by a coefficient of 0.8 along the axis of rotation. During the gravitational contraction, the major part of the cloud transformed into a planet and a minor part transformed into a disk. The thin structured disk is a result of the electromagnetic interaction in which the magnetic forces acting on charged particles of the cloud originate from the core of the planet.
基金Project supported by National Natural Science Foundation of China (51462010)Natural Science Foundation of Jiangxi Province(20161BAB206132,20171ACB20022)The Innovation fund of Jingdezhen Ceramic Institute (JYC-201803)。
文摘In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).
基金supported by the National Natural Science Foundation of China(Grant No.41725008)the National Key R&D Program of China(Grant No.2018YFA0702704)。
文摘Redox state is an important parameter in describing the thermodynamic state of the Earth’s interior.In contrast to the considerable efforts in early studies that have been expended on the redox state of Earth’s different spheres,much attention in the recent about 10 years has been paid to the effects of redox state on the various geodynamical aspects of Earth’s interior,or more commonly the redox geodynamics.Redox geodynamics plays a critical role in driving many processes that are involved in the accretion,differentiation,and re-shaping of the Earth from its early birth to modern periods and from its surface to the deep interior,including the structure,composition,nature,and evolution of the Earth and the significant effects on many important issues such as the climate change and habitability of the planet.This field has blossomed in these years around the chemical and physical properties of the Earth.In this review,a brief summary is provided for the basic concepts,general background and applications relevant to redox geodynamics.The redox state of the crust and mantle and its evolution have received particular attention in the past years,however,there are still fundamental issues remaining ambiguous,poorly quantified and/or even controversial.At the same time,significant progress has been made,mostly through experimental studies,on the redox geodynamics of the Earth’s interior,including(but are not limited to)the early oxidation of the shallow mantle,the rapid growth of the early continental crust,the redox freezing and melting associated with carbon or hydrogen,the transfer of metal elements and formation of ore deposits,the low seismic velocity and high attenuation of the asthenosphere,the aerobic processes around the core-mantle boundary,and the magma degassing and released gases.Redox geodynamics is becoming increasingly important in renewing the understanding of the chemical evolution,physical properties,and dynamical processes of the Earth.
文摘Mean heat flows and heat losses of the Northern and Southern hemispheres are calculated using degree 12 spherical harmonic representation of the global heat flow field (Pollack et al., 1993). Mean heat flows and heat losses of 0° hemisphere and 180° hemisphere, with median lines being 0° longitude and 180° longitude, are also calculated. The mean heat flow of the Southern Hemisphere is 99.3 mW·m -2, significantly higher than that of the Northern Hemisphere (74.0 mW·m -2). The mean heat flow of 0° hemisphere (94.1 mW·m -2) is also higher than the value of 180° hemisphere (79.3 mW·m -2). The mantle heat loss from the Southern Hemisphere is 22.1×10 12 W, as twice as that from the Northern Hemisphere ( 10.8×10 12 W). The 16.9×10 12 W mantle heat loss from 0° hemisphere is close to 16.0×10 12 W from 180° hemisphere. The hemispherical asymmetry of global heat loss is originated by the asymmetry of geographic distribution of continents and oceans. The asymmetric distribution of heat loss is a long-term phenomenon in the geological history.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20272053)the Natural Science Foundation of Zhejiang Province,China(Grant No.200016).
文摘The reaction of 3,6-di-(3-methyl-pyridin-2-yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3 · 6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2 (H2O)3] · NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2) nm, c = 1.4572(3) nm, α= 102.13(2)°, β= 99.81(3)°, γ= 91.10(3)°, Z = 2, V = 1113.6(7) nm3, μ = 2.123 mm?1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.
