Coronitic microstructures have been used to interpret the late-stage solidification history of igneous rocks and to constrain the corresponding chemical and/or physical changes.Coronas with three shells were also reco...Coronitic microstructures have been used to interpret the late-stage solidification history of igneous rocks and to constrain the corresponding chemical and/or physical changes.Coronas with three shells were also recognized in the Miaowan olivine norite,Yangtze Craton,South China.In our study,orthopyroxene intergrowth with vermicular magnetite in the inner shell is in optical continuity with magnetite-free orthopyroxene in the middle shell.In the outer shell of brown amphibole remaining magnetite-free orthopyroxene inclusions sporadically occur.Meanwhile Mg#values of orthopyroxene(76–80)in the inner and middle shells are basically consistent with olivine(78–81).In this paper,we propose a multi-stage genetic model for the formation of coronas in the Miaowan olivine norite.In the first stage,the magnetite-free orthopyroxene shell formed through reaction between primocrystal olivine with the residual Si-rich melt at 990–1053℃and 6.2–6.5 kbar.In the second stage,the orthopyroxene-magnetite symplectite shell formed when primocrystal olivine reacted with the late-stage residual Fe-rich melt promoted by high oxygen fugacity condition at 927–1035℃and 6.0–6.5 kbar.In the third stage,the brown amphibole shell formed as the presence of residual hydrous melt and replaced the middle shell at 821–900℃and 5.5–6.0 kbar.展开更多
Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering （DLS） and transmission electron microscopy （TEM） to investigate the adsorption of serum proteins...Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering （DLS） and transmission electron microscopy （TEM） to investigate the adsorption of serum proteins, including bovine serum albumin （BSA）, transferrin （TRF） and fibrinogen （FIB）, on gold nanoparticles （AuNPs） with different surface modifications （citrate, thioglycolic acid, cysteine, polyethylene glycol （PEG, Mw = 2 k and 5 k））. AuNPs with PEG（5 k） surface modification showed no protein adsorption. AuNPs with non-PEG surface modifications showed aggregation with FIB. AuNPs with citrate and thioglycolic acid surface modifications showed 6-8 nm thick BSA and TRF coronas （corres- ponding to monolayer or bilayer proteins）, in which the microscopic dissociation constants of BSA and TRF protein coronas are in the range of 104 to 104 M.展开更多
In this paper,we give some sufficient conditions for extended neighborhood coronas to have Laplacian perfect state transfer.We also give some conditions for extended neighborhood coronas to be periodic.
The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence em...The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence emission through protein coronas-controlled distance between gold nanoclusters(Au NCs).Interestingly,the gold ion complexes coated with proteins of low isoelectric point(pI)nucleate at the secondary structure of proteins with high p I through ionic exchange within cells,generating fluorescent Au NCs.It is worth noting that due to the steric hindrance formed by the protein coronas on the surface of Au NCs,the distance between Au NCs can be controlled,avoiding electron transfer caused by close proximity of Au NCs and inhibiting fluorescence ACQ.This strategy can achieve fluorescence imaging of clinical tissue samples without observable side effects.Therefore,this study proposes a distance-controllable self-assembled pitaya structure to provide a new approach for Au NCs with stable fluorescence.展开更多
In this paper a fully parametrized finite element simulation model of the stator bar end is created using the COMSOL Multiphysics.The model allows conducting the comparison of different corona protection structures’d...In this paper a fully parametrized finite element simulation model of the stator bar end is created using the COMSOL Multiphysics.The model allows conducting the comparison of different corona protection structures’design,various materials properties,and finally optimizing the corona protection system.Several samples of SiC based nonlinear conductivity materials for corona protection were fabricated in laboratory and then investigated.The conductivity dependencies on electric field(0.05 to 1 kV/mm)and temperature(20 to 155℃)were measured.By comparing the heat-resistant grades of the corona protection material and the insulating material,the maximum working temperature of the corona protection material corresponds to the heat-resistant grade F of the insulating material.As the temperature increases,the nonlinear characteristics of the corona protection material in the experiment decrease dramatically,reducing the heat-resistant grade of the corona protection material.The decrease in the nonlinear characteristics of the corona protection material at the maximum operating temperature causes the maximum electric field strength at the end of the HV rotating machines end corona protection(ECP)exceeding the corona discharge electric field strength,resulting in corona phenomenon.展开更多
Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface...Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface of a polarized spherical metal nanoparticle was studied.A mathematical model of the structure of the block copolymer chain adsorbed on a polarized spherical nanoparticle is presented for the cases of polyelectrolyte blocks of large and small length.Based on the modeling results,radial and angular distributions of the density of atoms of polyelectrolyte polypeptides adsorbed on the surface of a spherical nanoparticle were calculated depending on its dipole moment.As the dipole moment of the nanoparticle increased,the dense macromolecular shell was destroyed,forming caps of polyelectrolyte macro molecules or fragments of block copolymer of different types on the poles of the polarized nanoparticle.In this case,the macromolecular corona in the region of the poles of the polarized nanoparticle swelled the more strongly,the greater the distance between the charged links in the polymer.展开更多
Elucidation of the interactions of crop plants with clay minerals is essential for understanding the roles of clay minerals in terrestrial ecosystems.The prevailing hypothesis suggests that the physiological barriers ...Elucidation of the interactions of crop plants with clay minerals is essential for understanding the roles of clay minerals in terrestrial ecosystems.The prevailing hypothesis suggests that the physiological barriers of plant roots prevent the direct uptake of these large-size particles.However,whether crops can directly take up clay mineral particles remains unknown.Montmorillonite is a ubiquitous and important clay mineral in soil.This study used covalent fluorescence labeling and microscopic techniques to investigate the uptake and transport of montmorillonite particles by wheat(Triticum aestivum L.)in hydroponic solution,quartz sand matrix,and sandy loam soil.Additionally,the surface attachments of montmorillonite particles in xylem sap were analyzed at the nanoscale level with transmission electron microscopy and atomic force microscopy combined with infrared spectroscopy.Our results confirmed that micrometer-sized montmorillonite particles could enter the root steles of wheat seedlings from the sites of new lateral root emergence and were subsequently transported upward to the shoots and leaves through the vasculature via the transpiration stream.In this process,the surfaces of the montmorillonites adsorbed inorganic mineral nutrients and were covered by a layer of biomolecular coronas.This study reveals the potential for crop plant uptake of micrometer-sized montmorillonite particles and complements existing theories regarding the interactions of clay minerals with crop plants.Furthermore,the findings may lay a foundation for future studies on clay mineral interactions with crop plants in terrestrial ecosystems.展开更多
Magnetic reconnection driving a two-sided-loop jet is typically associated with interactions between an emerging bipole and the overlying horizontal magnetic field,or between filaments from separate magnetic systems.L...Magnetic reconnection driving a two-sided-loop jet is typically associated with interactions between an emerging bipole and the overlying horizontal magnetic field,or between filaments from separate magnetic systems.Leveraging high temporal and spatial resolution observations from ground-based and space-borne instruments,we have identified a two-sided-loop jet originating from magnetic reconnection between threads within a single filament.Our observations show that as two initially crossing filamentary threads within the filament converge,reconnection takes place at their intersection.In the Doppler images,distinct redshift and blueshift signals are observed at the locations where the filament threads intersected.This process generates a two-sided-loop jet with outflow speeds of 22.2 and 62.5 km s^(-1).Following reconnection,the original crossing threads transform into two parallel threads that subsequently separate at speeds of 2.8 and 8.3kms^(-1).This observation offers a new perspective on the mechanisms responsible for jet formation.展开更多
This study analyzes the evolution and dynamics of intensity oscillations in coronal sunspots and their surroundings using multi-wavelength image data from the Atmospheric Imaging Assembly(AIA)and Helioseismic and Magn...This study analyzes the evolution and dynamics of intensity oscillations in coronal sunspots and their surroundings using multi-wavelength image data from the Atmospheric Imaging Assembly(AIA)and Helioseismic and Magnetic Imager(HMI)on board the Solar Dynamics Observatory(SDO).Intensity time series were extracted and analyzed from consecutive macropixels along thin coronal loop paths originating in a quiet sunspot.Fourier and wavelet analyses of corrected intensity time series reveal dominant 3 and 5 minute oscillations.Signals were filtered using the Fourier and inverse transforms to isolate narrow bands around the dominant oscillation periods.Diagrams and time-distance maps of intensity time series were plotted for Fourierfiltered AIA 131A,171A,193A,and 211A channels,along with SDO/HMI magnetograms and dopplergrams at 6173A.The plots clearly show propagating oscillations with amplitude modulation(AM)across all macropixels along selected coronal paths in nearly all AIA and HMI channels.The phase speeds of the filtered oscillations,measured via slope calculations in time-distance maps,indicate that the intensity disturbances are slow magneto-acoustic waves.These results suggest that AM likely arises from the superposition of counterpropagating waves with slightly different frequencies(beta-like phenomena)due to Doppler shifts from background plasma flow along loop paths.Validating this hypothesis could establish AM's significance in solar coronal seismology for determining background plasma flow speed,the source of long-period oscillations,and coronal plasma heating mechanisms.展开更多
Heating mechanism in the solar atmosphere(from chromosphere to corona)is one of the top-challenges in modern astronomy.The classic mechanisms can be divided into two categories:wave heating(W)and magnetic reconnection...Heating mechanism in the solar atmosphere(from chromosphere to corona)is one of the top-challenges in modern astronomy.The classic mechanisms can be divided into two categories:wave heating(W)and magnetic reconnection heating(X).Both of them still face some problems currently difficult to overcome.Recently,we proposed a new mechanism,called magnetic-gradient pumping heating(MGP,or P)which seems to overcome those difficulties,but still lacks sufficient observational evidence.Which one really explained the physics of hot corona exactly?How can observations be used to identify and verify the heating mechanism?Since different heating mechanisms will generate non-thermal particles from different accelerations and experience different propagations,they will have different responses in the broadband spectral radio observations.Among them,the non-thermal electrons from W mechanisms are closely related to shock-wave acceleration,and their radio response should be a group of spike bursts with random distribution of drifting rates;the non-thermal electrons from X mechanisms are accelerated by reconnecting electric field with bidirectional flow,and their radio response should be type III pairs or spike pairs;P mechanism will produce energetic particle upflows,and their radio response should be unidirectional fiber bursts with moderate negative drifting rates.Therefore,the heating mechanism can be identified and verified from the broadband dynamic spectral radio observations.Additionally,using high-resolution radioheliographs and spectral-imaging observations,the heating mechanisms in different regions can be identified and verified separately,thereby demonstrating the physical essence of the hot corona.展开更多
Urban open spaces(UOS)play a crucial role in enhancing city livability and resident well-being,yet there remains a gap in utilizing social media to analyze changes in UOS utilization across different COVID(Corona Viru...Urban open spaces(UOS)play a crucial role in enhancing city livability and resident well-being,yet there remains a gap in utilizing social media to analyze changes in UOS utilization across different COVID(Corona Virus Disease)-19 phases.Our research applied Sina Weibo data to scrutinize UOS engagement across pre-pandemic(2019),pandemic(2021),and post-pandemic(2023)periods in Lanzhou City,China,revealing evolving spatiotemporal patterns and highlighting the pandemic's impact on UOS usage.Initially,scenic mountains and urban parks dominated visitor preferences in 2019.However,during the pandemic,there was a trend towards destinations that combined elements of tourism,business,entertainment,and culture,reflecting a growing appetite for diverse experiences.Despite this shift,the post-pandemic period did not see a complete return to pre-pandemic travel patterns,with a noticeable decline in visits to traditional green open spaces during lockdowns.We identified key attractions in main urban areas,highlighting geographical variations in tourism and Cultural Ecosystem Services(CES)distribution that warrant further attention.The post-pandemic landscape reveals a resurging interest in green-blue spaces and nature-focused tourism,highlighting a continued preference for cultural and natural experiences,and emphasizing the need to harmonize development with the preservation of natural and cultural heritage.This study introduces the use of social media data across pandemic phases to guide UOS management,offering insights for creating resilient,multifunctional urban spaces that address public needs and enhance community well-being.展开更多
利用解密的美国CORONA卫星影像,在库车冲断褶皱带,开展大面积地表构造调查,获取地区的地表产状.通过建立有理函数模型(rational function model,RFM)校正CORONA影像的全景变形,利用JX-4C数字摄影测量系统进行CORONA影像的立体观测和测量...利用解密的美国CORONA卫星影像,在库车冲断褶皱带,开展大面积地表构造调查,获取地区的地表产状.通过建立有理函数模型(rational function model,RFM)校正CORONA影像的全景变形,利用JX-4C数字摄影测量系统进行CORONA影像的立体观测和测量,确定岩层面的高程值,并采用三点法在MATLAB软件中计算岩层的倾角和走向,获取地表产状.通过和野外实测数据对比,测量误差小于3°,满足了构造定量解析的精度要求.应用获取的构造产状结合二维地震反射资料,根据断层相关褶皱原理定量地提取库车地区褶皱和断层的几何学特征.展开更多
基金financially supported by the National Key Research and the Development Program of China(No.2016YFC0600502)the National Natural Science Foundation of China(No.41502046)the Geological Survey Project of China(No.DD20160030)
文摘Coronitic microstructures have been used to interpret the late-stage solidification history of igneous rocks and to constrain the corresponding chemical and/or physical changes.Coronas with three shells were also recognized in the Miaowan olivine norite,Yangtze Craton,South China.In our study,orthopyroxene intergrowth with vermicular magnetite in the inner shell is in optical continuity with magnetite-free orthopyroxene in the middle shell.In the outer shell of brown amphibole remaining magnetite-free orthopyroxene inclusions sporadically occur.Meanwhile Mg#values of orthopyroxene(76–80)in the inner and middle shells are basically consistent with olivine(78–81).In this paper,we propose a multi-stage genetic model for the formation of coronas in the Miaowan olivine norite.In the first stage,the magnetite-free orthopyroxene shell formed through reaction between primocrystal olivine with the residual Si-rich melt at 990–1053℃and 6.2–6.5 kbar.In the second stage,the orthopyroxene-magnetite symplectite shell formed when primocrystal olivine reacted with the late-stage residual Fe-rich melt promoted by high oxygen fugacity condition at 927–1035℃and 6.0–6.5 kbar.In the third stage,the brown amphibole shell formed as the presence of residual hydrous melt and replaced the middle shell at 821–900℃and 5.5–6.0 kbar.
文摘Protein coronas provide the biological identity of nanomaterials in vivo. Here we have used dynamic light scattering （DLS） and transmission electron microscopy （TEM） to investigate the adsorption of serum proteins, including bovine serum albumin （BSA）, transferrin （TRF） and fibrinogen （FIB）, on gold nanoparticles （AuNPs） with different surface modifications （citrate, thioglycolic acid, cysteine, polyethylene glycol （PEG, Mw = 2 k and 5 k））. AuNPs with PEG（5 k） surface modification showed no protein adsorption. AuNPs with non-PEG surface modifications showed aggregation with FIB. AuNPs with citrate and thioglycolic acid surface modifications showed 6-8 nm thick BSA and TRF coronas （corres- ponding to monolayer or bilayer proteins）, in which the microscopic dissociation constants of BSA and TRF protein coronas are in the range of 104 to 104 M.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11601431,11871398,12071370,U1803263 and 12131013)the Natural Science Foundation of Shaanxi Province(Grant No.2020JM-099)the Natural Science Foundation of Qinghai Province(Grant No.2020-ZJ-920)。
文摘In this paper,we give some sufficient conditions for extended neighborhood coronas to have Laplacian perfect state transfer.We also give some conditions for extended neighborhood coronas to be periodic.
基金supported by the National Natural Science Foundation of China(Nos.82061148012,82027806,21974019)SEU Innovation Capability Enhancement Plan for Doctoral Students(No.CXJH_SEU 24138)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_0469)。
文摘The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching(ACQ).In this study,an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence emission through protein coronas-controlled distance between gold nanoclusters(Au NCs).Interestingly,the gold ion complexes coated with proteins of low isoelectric point(pI)nucleate at the secondary structure of proteins with high p I through ionic exchange within cells,generating fluorescent Au NCs.It is worth noting that due to the steric hindrance formed by the protein coronas on the surface of Au NCs,the distance between Au NCs can be controlled,avoiding electron transfer caused by close proximity of Au NCs and inhibiting fluorescence ACQ.This strategy can achieve fluorescence imaging of clinical tissue samples without observable side effects.Therefore,this study proposes a distance-controllable self-assembled pitaya structure to provide a new approach for Au NCs with stable fluorescence.
文摘In this paper a fully parametrized finite element simulation model of the stator bar end is created using the COMSOL Multiphysics.The model allows conducting the comparison of different corona protection structures’design,various materials properties,and finally optimizing the corona protection system.Several samples of SiC based nonlinear conductivity materials for corona protection were fabricated in laboratory and then investigated.The conductivity dependencies on electric field(0.05 to 1 kV/mm)and temperature(20 to 155℃)were measured.By comparing the heat-resistant grades of the corona protection material and the insulating material,the maximum working temperature of the corona protection material corresponds to the heat-resistant grade F of the insulating material.As the temperature increases,the nonlinear characteristics of the corona protection material in the experiment decrease dramatically,reducing the heat-resistant grade of the corona protection material.The decrease in the nonlinear characteristics of the corona protection material at the maximum operating temperature causes the maximum electric field strength at the end of the HV rotating machines end corona protection(ECP)exceeding the corona discharge electric field strength,resulting in corona phenomenon.
基金the financial support of the Ministry of Science and Higher Education of the Russian Federation within the framework of a grant for conducting large scientific projects in priority areas of scientific and technological development 075-15-2024-550。
文摘Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface of a polarized spherical metal nanoparticle was studied.A mathematical model of the structure of the block copolymer chain adsorbed on a polarized spherical nanoparticle is presented for the cases of polyelectrolyte blocks of large and small length.Based on the modeling results,radial and angular distributions of the density of atoms of polyelectrolyte polypeptides adsorbed on the surface of a spherical nanoparticle were calculated depending on its dipole moment.As the dipole moment of the nanoparticle increased,the dense macromolecular shell was destroyed,forming caps of polyelectrolyte macro molecules or fragments of block copolymer of different types on the poles of the polarized nanoparticle.In this case,the macromolecular corona in the region of the poles of the polarized nanoparticle swelled the more strongly,the greater the distance between the charged links in the polymer.
基金supported by the National Natural Science Foundation of China(Nos.41991330,22241602,and 42177039)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZC20232783)。
文摘Elucidation of the interactions of crop plants with clay minerals is essential for understanding the roles of clay minerals in terrestrial ecosystems.The prevailing hypothesis suggests that the physiological barriers of plant roots prevent the direct uptake of these large-size particles.However,whether crops can directly take up clay mineral particles remains unknown.Montmorillonite is a ubiquitous and important clay mineral in soil.This study used covalent fluorescence labeling and microscopic techniques to investigate the uptake and transport of montmorillonite particles by wheat(Triticum aestivum L.)in hydroponic solution,quartz sand matrix,and sandy loam soil.Additionally,the surface attachments of montmorillonite particles in xylem sap were analyzed at the nanoscale level with transmission electron microscopy and atomic force microscopy combined with infrared spectroscopy.Our results confirmed that micrometer-sized montmorillonite particles could enter the root steles of wheat seedlings from the sites of new lateral root emergence and were subsequently transported upward to the shoots and leaves through the vasculature via the transpiration stream.In this process,the surfaces of the montmorillonites adsorbed inorganic mineral nutrients and were covered by a layer of biomolecular coronas.This study reveals the potential for crop plant uptake of micrometer-sized montmorillonite particles and complements existing theories regarding the interactions of clay minerals with crop plants.Furthermore,the findings may lay a foundation for future studies on clay mineral interactions with crop plants in terrestrial ecosystems.
基金supported by the National Natural Science Foundation of China(NSFC,grant Nos.12303062 and 12203043)the Sichuan Science and Technology Program(2023NSFSC1351,2025ZNSFSC0315)+1 种基金Key Laboratory of Detection and Application of Space Effect in Southwest Sichuan at Leshan Normal University,Education Department of Sichuan Province(No.ZDXM20241002)Project Supported by the Specialized Research Fund for State Key Laboratory of Solar Activity and Space Weather。
文摘Magnetic reconnection driving a two-sided-loop jet is typically associated with interactions between an emerging bipole and the overlying horizontal magnetic field,or between filaments from separate magnetic systems.Leveraging high temporal and spatial resolution observations from ground-based and space-borne instruments,we have identified a two-sided-loop jet originating from magnetic reconnection between threads within a single filament.Our observations show that as two initially crossing filamentary threads within the filament converge,reconnection takes place at their intersection.In the Doppler images,distinct redshift and blueshift signals are observed at the locations where the filament threads intersected.This process generates a two-sided-loop jet with outflow speeds of 22.2 and 62.5 km s^(-1).Following reconnection,the original crossing threads transform into two parallel threads that subsequently separate at speeds of 2.8 and 8.3kms^(-1).This observation offers a new perspective on the mechanisms responsible for jet formation.
文摘This study analyzes the evolution and dynamics of intensity oscillations in coronal sunspots and their surroundings using multi-wavelength image data from the Atmospheric Imaging Assembly(AIA)and Helioseismic and Magnetic Imager(HMI)on board the Solar Dynamics Observatory(SDO).Intensity time series were extracted and analyzed from consecutive macropixels along thin coronal loop paths originating in a quiet sunspot.Fourier and wavelet analyses of corrected intensity time series reveal dominant 3 and 5 minute oscillations.Signals were filtered using the Fourier and inverse transforms to isolate narrow bands around the dominant oscillation periods.Diagrams and time-distance maps of intensity time series were plotted for Fourierfiltered AIA 131A,171A,193A,and 211A channels,along with SDO/HMI magnetograms and dopplergrams at 6173A.The plots clearly show propagating oscillations with amplitude modulation(AM)across all macropixels along selected coronal paths in nearly all AIA and HMI channels.The phase speeds of the filtered oscillations,measured via slope calculations in time-distance maps,indicate that the intensity disturbances are slow magneto-acoustic waves.These results suggest that AM likely arises from the superposition of counterpropagating waves with slightly different frequencies(beta-like phenomena)due to Doppler shifts from background plasma flow along loop paths.Validating this hypothesis could establish AM's significance in solar coronal seismology for determining background plasma flow speed,the source of long-period oscillations,and coronal plasma heating mechanisms.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences XDB0560000the National Key R&D Program of China 2021YFA1600503,2022YFF0503001,2022YFF0503800+1 种基金the National Natural Science Foundation of China(NSFC,Grant No.12173050)the International Partnership Program of the Chinese Academy of Sciences 183311KYSB20200003。
文摘Heating mechanism in the solar atmosphere(from chromosphere to corona)is one of the top-challenges in modern astronomy.The classic mechanisms can be divided into two categories:wave heating(W)and magnetic reconnection heating(X).Both of them still face some problems currently difficult to overcome.Recently,we proposed a new mechanism,called magnetic-gradient pumping heating(MGP,or P)which seems to overcome those difficulties,but still lacks sufficient observational evidence.Which one really explained the physics of hot corona exactly?How can observations be used to identify and verify the heating mechanism?Since different heating mechanisms will generate non-thermal particles from different accelerations and experience different propagations,they will have different responses in the broadband spectral radio observations.Among them,the non-thermal electrons from W mechanisms are closely related to shock-wave acceleration,and their radio response should be a group of spike bursts with random distribution of drifting rates;the non-thermal electrons from X mechanisms are accelerated by reconnecting electric field with bidirectional flow,and their radio response should be type III pairs or spike pairs;P mechanism will produce energetic particle upflows,and their radio response should be unidirectional fiber bursts with moderate negative drifting rates.Therefore,the heating mechanism can be identified and verified from the broadband dynamic spectral radio observations.Additionally,using high-resolution radioheliographs and spectral-imaging observations,the heating mechanisms in different regions can be identified and verified separately,thereby demonstrating the physical essence of the hot corona.
基金Under the auspices of National Natural Science Foundation of China(No.42401232,72050001)Natural Science Foundation of Gansu Province(No.24JRRA419)Research Funds for Blue Green Infrastructure Planning and Ecological Restoration in Mining Cities(No.071124044/(24)0315)。
文摘Urban open spaces(UOS)play a crucial role in enhancing city livability and resident well-being,yet there remains a gap in utilizing social media to analyze changes in UOS utilization across different COVID(Corona Virus Disease)-19 phases.Our research applied Sina Weibo data to scrutinize UOS engagement across pre-pandemic(2019),pandemic(2021),and post-pandemic(2023)periods in Lanzhou City,China,revealing evolving spatiotemporal patterns and highlighting the pandemic's impact on UOS usage.Initially,scenic mountains and urban parks dominated visitor preferences in 2019.However,during the pandemic,there was a trend towards destinations that combined elements of tourism,business,entertainment,and culture,reflecting a growing appetite for diverse experiences.Despite this shift,the post-pandemic period did not see a complete return to pre-pandemic travel patterns,with a noticeable decline in visits to traditional green open spaces during lockdowns.We identified key attractions in main urban areas,highlighting geographical variations in tourism and Cultural Ecosystem Services(CES)distribution that warrant further attention.The post-pandemic landscape reveals a resurging interest in green-blue spaces and nature-focused tourism,highlighting a continued preference for cultural and natural experiences,and emphasizing the need to harmonize development with the preservation of natural and cultural heritage.This study introduces the use of social media data across pandemic phases to guide UOS management,offering insights for creating resilient,multifunctional urban spaces that address public needs and enhance community well-being.
文摘利用解密的美国CORONA卫星影像,在库车冲断褶皱带,开展大面积地表构造调查,获取地区的地表产状.通过建立有理函数模型(rational function model,RFM)校正CORONA影像的全景变形,利用JX-4C数字摄影测量系统进行CORONA影像的立体观测和测量,确定岩层面的高程值,并采用三点法在MATLAB软件中计算岩层的倾角和走向,获取地表产状.通过和野外实测数据对比,测量误差小于3°,满足了构造定量解析的精度要求.应用获取的构造产状结合二维地震反射资料,根据断层相关褶皱原理定量地提取库车地区褶皱和断层的几何学特征.
