Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high ...Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high pressure-temperature(high P-T)conditions to~17.7 GPa and 700 K.No phase transition occurs over this P-T range.Using the third-order Birch-Murnaghan equation of state(EoS),we fitted the pressure-volume-temperature(P-V-T)data and obtained the zero-pressure bulk modulus K_(0)=138(2)GPa,its pressure derivative K'_(0)=3.0(3),the temperature derivative of the bulk modulus((∂K/∂T)P=-0.004(1)GPa/K),and the thermal expansion coefficient at 300 K(α_(0)=3.8(5)×10^(-5)K^(-1)),as the zero-pressure unit-cell volume V_(0)was fixed at 465.2(2)Å^(3)(obtained by a single-crystal XRD experiment at ambient conditions).This study reveals that the bulk moduli of epidote show nonlinear compositional dependence.By discussing the stabilization of epidote and comparing its density with those of other hydrous minerals,we find that epidote,as a significant water transporter in subduction zones,may maintain a metastable state to~14 GPa along the coldest subducting slab geotherm and promote slab subduction into the upper mantle while favoring slab stagnation above the 410 km discontinuity.Furthermore,the water released from epidote near 410 km may potentially affect the properties of the 410 km seismic discontinuity.展开更多
Mesozoic intermediate-felsic magmatic rocks in the eastern North China Craton commonly show geochemical similarity to adakites.However,the lack of direct constraints from partial melting experiments at high pressures ...Mesozoic intermediate-felsic magmatic rocks in the eastern North China Craton commonly show geochemical similarity to adakites.However,the lack of direct constraints from partial melting experiments at high pressures and temperatures fuels a debate over the origin of these rocks.In this work,we performed partial melting experiments at 1.5 GPa and 800–950℃on amphibolite samples collected from the vicinity of the Mesozoic potassium-rich adakitic rocks in the Zhangjiakou area,northern margin of the North China Craton.The experimental melts range from granitic to granodioritic compositions,with SiO_(2)=56.4–72.6 wt.%,Al_(2)O_(3)=16.1–19.3 wt.%,FeO^(*)=2.4–9.6 wt.%,MgO=0.3–2.0 wt.%,CaO=0.6–3.8 wt.%,Na_(2)O=4.7–5.3 wt.%,and K_(2)O=2.6–3.9 wt.%,which are in the ranges of the surrounding Mesozoic potassium-rich adakitic rocks,except for the higher Al_(2)O_(3)contents and the data point at 1.5 GPa and 800℃.Trace element compositions of the melts measured by LA-ICP-MS are rich in Sr(849–1067 ppm)and light rare earth elements(LREEs)and poor in Y(<10.4 ppm)and Yb(<0.88 ppm),and have high Sr/Y(102–221)and(La/Yb)n(27–41)ratios and strongly fractionated rare earth element(REE)patterns,whereas no obvious negative Eu anomalies are observed.The geochemical characteristics show overall similarity to the Mesozoic potassium-rich adakitic rocks in the area,especially adakites with low Mg#,again except for the data point at 1.5 GPa and 800℃.The results suggest that partial melting of amphibolite can produce potassium-rich adakitic rocks with low Mg#in the eastern North China Craton under the experimental conditions of 1.5 GPa and 850–950℃.The experimental restites consist of hornblende(Hbl)+plagioclase(Pl)+garnet(Grt)±clinopyroxene(Cpx),a mineral assemblage significantly different from that of the nearby Hannuoba mafic granulite xenoliths which consist of Cpx+orthopyroxene(Opx)+Pl±Grt.Chemically,the experimental restites contain higher Al_(2)O_(3)but lower MgO and CaO than the Hannuoba mafic granulite xenoliths.We therefore argue that the Hannuoba mafic granulite xenoliths cannot represent the direct products of partial melting of the experimental amphibolite.展开更多
In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density a...In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density and heat capacity data at ambient pressure, the density,adiabatic bulk modulus, shear modulus, and most importantly, thermal expansion and heat capacity, of San Carlos are extracted to 14 GPa by a numerical procedure using classic thermodynamic relationships. These data are in agreement with published findings. To estimate the temperature gradient in the upper mantle, we also report the fitting equations of thermal expansion and heat capacity of San Carlos olivine as a function of both temperature and pressure to the P–T condition of the 410 km discontinuity,which provide the thermodynamic properties with increasing depth in the Earth's interior.展开更多
In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours w...In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours were utilized. From November 2015 to February 2016, the relevant materials were used as research samples (a total of 948 times), and from November 2016 to February 2017 as test samples (a total of 922 times), statistical methods were used to establish the scoring standards. And each relevant element was scored. After the score, the score level range was delineated, and the visibility forecast was performed according to the scope. The conclusions are as follows: 1) European fine grid forecast products are with good correspondence with the visibility of this field are 850 hPa and 2 m high temperature inversion, 850 hPa relative humidity and 850 hPa wind field over the field. 2) Through the statistical analysis of scores, it is defined that the score below 400 is level 4, the score above 1000 is level 1, the difference is significant, and the forecast indication is strong. Level 2 and level 3 are more evenly distributed, with no more concentrated fractions. 3) Applying the test sample to test the above indicators. The forecast accuracy of level 1 is 61.2%, and the forecast accuracy of level 4 is 97.2%, so level 1 and level 4 are expected to obtain better forecast results, which is of practical application value.展开更多
The unit-cell parameters and volumes of geikielite(MgTiO_(3))and ilmenite(FeTiO_(3))were investigated at high temperatures up to 700 K and ambient pressure,using in-situ angle-dispersive synchrotron X-ray diffraction....The unit-cell parameters and volumes of geikielite(MgTiO_(3))and ilmenite(FeTiO_(3))were investigated at high temperatures up to 700 K and ambient pressure,using in-situ angle-dispersive synchrotron X-ray diffraction.No phase transition was detected over the experimental temperature range.Using(Berman in J Petrol29:445-522,1988.10.1093/petrology/29.2.445)equations to fit the temperature-volume data,the volumetric thermal expansion coefficients at ambient conditions(α_(V0))of MgTiO_(3) and FeTiO_(3) were obtained as follows:2.55(6)×10^(-5)K^(-1)and 2.82(10)×10^(-5)K^(-1),respectively.We infer that the larger effective ionic radius of Fe^(2+)(Ⅵ)(0.78 A)than that of Mg^(2+)(Ⅵ)(0.72?)renders FeTiO_(3)has a larger volumetric thermal expansivity than MgTiO_(3).Simultaneously,the refined axial thermal expansion coefficients under ambient conditions areα_(a0)=0.74(3)×10^(-5)K^(-1)andα_(c0)=1.08(5)×10^(-5)K^(-1)for the aaxis and c-axis of MgTiO_(3),respectively,andα_(a0)=0.95(5)×10^(-5)K^(-1)andα_(c0)=0.92(12)×10^(-5)K^(-1)for the aaxis and c-axis of FeTiO_(3),respectively.The axial thermal expansivity of MgTiO_(3) is anisotropic,but that of FeTiO_(3) is nearly isotropic.We infer that the main reason for the different axial thermal expansivity between MgTiO_(3) and FeTiO_(3) is that the thermal expansion mode of the Mg-O bond in MgTiO_(3) is different from that of the Fe-O bonds in FeTiO_(3).展开更多
Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precio...Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.展开更多
Photoelectrochemical(PEC)active interfaces exhibiting visible-light responses and good electron-transfer ca-pabilities are key to the development of PEC biosensors.In this study,bioinspired polydopamine(PDA)-polyethyl...Photoelectrochemical(PEC)active interfaces exhibiting visible-light responses and good electron-transfer ca-pabilities are key to the development of PEC biosensors.In this study,bioinspired polydopamine(PDA)-polyethyleneimine(PEI)hybrid films were designed to engineer inorganic semiconductors and construct PEC biosensing interfaces.The charge-transfer capability and visible-light-response property of PDA were combined with the electron-attracting ability of PEI to produce a synergistic PEC-enhancement effect.The achieved PEC-enhancement effect was versatile for photoanode and photocathode semiconductors.Further,the role of PEI doping was revealed via electrochemical investigations.Compared with the PDA sensing platform,the hybrid sensing interface offered by the PDA-PEI film exhibited enhanced analytical performances toward ascorbic acid(AA),achieving a larger detection range and a lower limit of detection.展开更多
基金the National Natural Science Foundation of China(Grant Nos.41772043 and 41802043)the CAS"Light of West China"Program(2017 and 2019),the Youth Innovation Promotion Association CAS(Dawei Fan,2018434)+4 种基金the Innovation and Entrepreneurship Funding of High-Level Overseas Talents of Guizhou Province(Dawei Fan,[2019]10)GeoSoilEnviroCARS(The University of Chicago,Sector 13)Advanced Photon Source(APS),Argonne National Laboratory.GeoSoilEnviroCARS is supported by the National Science Foundation(EAR-0622171)the Department of Energy(DE-FG02-94ER14466)under Contract No.DE-AC02-06CH11357the Advanced Photon Source,a U.S.Department of Energy(DOE)Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DE-AC02-06CH11357.
文摘Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high pressure-temperature(high P-T)conditions to~17.7 GPa and 700 K.No phase transition occurs over this P-T range.Using the third-order Birch-Murnaghan equation of state(EoS),we fitted the pressure-volume-temperature(P-V-T)data and obtained the zero-pressure bulk modulus K_(0)=138(2)GPa,its pressure derivative K'_(0)=3.0(3),the temperature derivative of the bulk modulus((∂K/∂T)P=-0.004(1)GPa/K),and the thermal expansion coefficient at 300 K(α_(0)=3.8(5)×10^(-5)K^(-1)),as the zero-pressure unit-cell volume V_(0)was fixed at 465.2(2)Å^(3)(obtained by a single-crystal XRD experiment at ambient conditions).This study reveals that the bulk moduli of epidote show nonlinear compositional dependence.By discussing the stabilization of epidote and comparing its density with those of other hydrous minerals,we find that epidote,as a significant water transporter in subduction zones,may maintain a metastable state to~14 GPa along the coldest subducting slab geotherm and promote slab subduction into the upper mantle while favoring slab stagnation above the 410 km discontinuity.Furthermore,the water released from epidote near 410 km may potentially affect the properties of the 410 km seismic discontinuity.
基金the National Natural Science Foundation of China(Grant Nos.41772043 and 41802043)the Chinese Academy of Sciences“Light of West China”Program(Dawei Fan,2017 and Jingui Xu,2019)+1 种基金the Youth Innovation Promotion Association CAS(Dawei Fan,2018434)the Innovation and Entrepreneurship Funding of High-Level Overseas Talents of Guizhou Province(Dawei Fan,[2019]10).
文摘Mesozoic intermediate-felsic magmatic rocks in the eastern North China Craton commonly show geochemical similarity to adakites.However,the lack of direct constraints from partial melting experiments at high pressures and temperatures fuels a debate over the origin of these rocks.In this work,we performed partial melting experiments at 1.5 GPa and 800–950℃on amphibolite samples collected from the vicinity of the Mesozoic potassium-rich adakitic rocks in the Zhangjiakou area,northern margin of the North China Craton.The experimental melts range from granitic to granodioritic compositions,with SiO_(2)=56.4–72.6 wt.%,Al_(2)O_(3)=16.1–19.3 wt.%,FeO^(*)=2.4–9.6 wt.%,MgO=0.3–2.0 wt.%,CaO=0.6–3.8 wt.%,Na_(2)O=4.7–5.3 wt.%,and K_(2)O=2.6–3.9 wt.%,which are in the ranges of the surrounding Mesozoic potassium-rich adakitic rocks,except for the higher Al_(2)O_(3)contents and the data point at 1.5 GPa and 800℃.Trace element compositions of the melts measured by LA-ICP-MS are rich in Sr(849–1067 ppm)and light rare earth elements(LREEs)and poor in Y(<10.4 ppm)and Yb(<0.88 ppm),and have high Sr/Y(102–221)and(La/Yb)n(27–41)ratios and strongly fractionated rare earth element(REE)patterns,whereas no obvious negative Eu anomalies are observed.The geochemical characteristics show overall similarity to the Mesozoic potassium-rich adakitic rocks in the area,especially adakites with low Mg#,again except for the data point at 1.5 GPa and 800℃.The results suggest that partial melting of amphibolite can produce potassium-rich adakitic rocks with low Mg#in the eastern North China Craton under the experimental conditions of 1.5 GPa and 850–950℃.The experimental restites consist of hornblende(Hbl)+plagioclase(Pl)+garnet(Grt)±clinopyroxene(Cpx),a mineral assemblage significantly different from that of the nearby Hannuoba mafic granulite xenoliths which consist of Cpx+orthopyroxene(Opx)+Pl±Grt.Chemically,the experimental restites contain higher Al_(2)O_(3)but lower MgO and CaO than the Hannuoba mafic granulite xenoliths.We therefore argue that the Hannuoba mafic granulite xenoliths cannot represent the direct products of partial melting of the experimental amphibolite.
基金supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences (XDB 18010401)Light of the West Foundation of Chinese Academy of Sciences (Y5CR025000)
文摘In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density and heat capacity data at ambient pressure, the density,adiabatic bulk modulus, shear modulus, and most importantly, thermal expansion and heat capacity, of San Carlos are extracted to 14 GPa by a numerical procedure using classic thermodynamic relationships. These data are in agreement with published findings. To estimate the temperature gradient in the upper mantle, we also report the fitting equations of thermal expansion and heat capacity of San Carlos olivine as a function of both temperature and pressure to the P–T condition of the 410 km discontinuity,which provide the thermodynamic properties with increasing depth in the Earth's interior.
文摘In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours were utilized. From November 2015 to February 2016, the relevant materials were used as research samples (a total of 948 times), and from November 2016 to February 2017 as test samples (a total of 922 times), statistical methods were used to establish the scoring standards. And each relevant element was scored. After the score, the score level range was delineated, and the visibility forecast was performed according to the scope. The conclusions are as follows: 1) European fine grid forecast products are with good correspondence with the visibility of this field are 850 hPa and 2 m high temperature inversion, 850 hPa relative humidity and 850 hPa wind field over the field. 2) Through the statistical analysis of scores, it is defined that the score below 400 is level 4, the score above 1000 is level 1, the difference is significant, and the forecast indication is strong. Level 2 and level 3 are more evenly distributed, with no more concentrated fractions. 3) Applying the test sample to test the above indicators. The forecast accuracy of level 1 is 61.2%, and the forecast accuracy of level 4 is 97.2%, so level 1 and level 4 are expected to obtain better forecast results, which is of practical application value.
基金supported by National Natural Science Foundation of China(U2032118 and 42172048)Guizhou Provincial Science and Technology Projects(QKHPTRCYQK[2023]035 and QKHJC-ZK[2021]ZD042)+1 种基金Hundred Talents Program of the Chinese Academy of SciencesGuizhou Provincial 2020 and 2021 Science and Technology Subsidies(Nos.GZ2020SIG and GZ2021SIG)。
文摘The unit-cell parameters and volumes of geikielite(MgTiO_(3))and ilmenite(FeTiO_(3))were investigated at high temperatures up to 700 K and ambient pressure,using in-situ angle-dispersive synchrotron X-ray diffraction.No phase transition was detected over the experimental temperature range.Using(Berman in J Petrol29:445-522,1988.10.1093/petrology/29.2.445)equations to fit the temperature-volume data,the volumetric thermal expansion coefficients at ambient conditions(α_(V0))of MgTiO_(3) and FeTiO_(3) were obtained as follows:2.55(6)×10^(-5)K^(-1)and 2.82(10)×10^(-5)K^(-1),respectively.We infer that the larger effective ionic radius of Fe^(2+)(Ⅵ)(0.78 A)than that of Mg^(2+)(Ⅵ)(0.72?)renders FeTiO_(3)has a larger volumetric thermal expansivity than MgTiO_(3).Simultaneously,the refined axial thermal expansion coefficients under ambient conditions areα_(a0)=0.74(3)×10^(-5)K^(-1)andα_(c0)=1.08(5)×10^(-5)K^(-1)for the aaxis and c-axis of MgTiO_(3),respectively,andα_(a0)=0.95(5)×10^(-5)K^(-1)andα_(c0)=0.92(12)×10^(-5)K^(-1)for the aaxis and c-axis of FeTiO_(3),respectively.The axial thermal expansivity of MgTiO_(3) is anisotropic,but that of FeTiO_(3) is nearly isotropic.We infer that the main reason for the different axial thermal expansivity between MgTiO_(3) and FeTiO_(3) is that the thermal expansion mode of the Mg-O bond in MgTiO_(3) is different from that of the Fe-O bonds in FeTiO_(3).
基金supported by the Space Debris and Near-Earth Asteroid Defense Research Project(KJSP2023020303)Youliang Wang is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022146).
文摘Asteroid mining is a potentially lucrative method for extracting resources from space. Water resources found on asteroids can serve as fuel supplies for spacecrafts in deep space, and some asteroids are rich in precious metals, offering immense potential economic value. The 12th Global Trajectory Optimization Competition, held in 2023, introduced a challenge to trajectory design for sustainable asteroid mining. Participating teams were tasked with maximizing the mining quantity over a 15-yr period by utilizing as many mining ships as possible to depart from the Earth, deploy miners on multiple asteroids, recover minerals, and return to the Earth. Σ team devised a strategy in which one ship completes one sequence, enabling the collection of minerals from 203 asteroids using 26 mining ships. This paper outlines the design methodology and outcomes of this approach, encompassing a preliminary analysis of the problem, optimization for the Earth departure and return, flight sequence search, and low-thrust conversion and optimization. Through methods such as asteroid selection and clustering, database building for Earth–asteroid transfers, global search with an impulsive model, local optimization with a low-thrust model, and conversion of remaining fuel into mining time, the computational efficiency was significantly enhanced, fuel consumption per unit mineral collection was reduced, and mining quantity was improved. Finally, the design outcomes of this approach are presented. The proposed trajectory design method enables the completion of multiple asteroid rendezvouses in a short time, providing valuable insights for future missions involving a single spacecraft conducting multiple rendezvouses with multiple asteroids.
基金the Shandong Provincial Natural Science Foundation(ZR2020YQ13)a Project of Shandong Province Higher Educational Youth Innovation Science and Technology Program(2020KJC008)Jinan Scientific Research Leader Workshop Project(2020GXRC048).
文摘Photoelectrochemical(PEC)active interfaces exhibiting visible-light responses and good electron-transfer ca-pabilities are key to the development of PEC biosensors.In this study,bioinspired polydopamine(PDA)-polyethyleneimine(PEI)hybrid films were designed to engineer inorganic semiconductors and construct PEC biosensing interfaces.The charge-transfer capability and visible-light-response property of PDA were combined with the electron-attracting ability of PEI to produce a synergistic PEC-enhancement effect.The achieved PEC-enhancement effect was versatile for photoanode and photocathode semiconductors.Further,the role of PEI doping was revealed via electrochemical investigations.Compared with the PDA sensing platform,the hybrid sensing interface offered by the PDA-PEI film exhibited enhanced analytical performances toward ascorbic acid(AA),achieving a larger detection range and a lower limit of detection.
