ABSTRACT： The Longmenshan Range is a tectonically composite intracontinental orogen. Its structure, deformation and spatial evolution reflect multiple kinematic eposides and variable dynamics especially during Post-M...ABSTRACT： The Longmenshan Range is a tectonically composite intracontinental orogen. Its structure, deformation and spatial evolution reflect multiple kinematic eposides and variable dynamics especially during Post-Middle to Post-Late Triassic time. Field work, lower-temperature thermochronological data and U-Pb detrital zircon ages indicate document down-dip zonation and along-strike segmentation dem- onstrated by significant differences in geological structure, intensity of deformation and deformation- involved strata, uplift and cooling processes. Low-temperature thermochronology and U-Pb detrital zir- con ages reveal a period of tectono-thermal quiescence with slow uplift and cooling during post Early Norian to Rhaetian orogeny, followed by rapid cooling and uplift during the Late Cenozoic accompanied by coeval southeastward thrusting and southwestward propagation of defromation. The Longmenshan Range formed by S-N striking compression exerted by the Qinling orogen, E-W striking compression by the Tibetan Plateau and SE-striking compression by the Yangtze Plate. We propose a southwestward propagation model for the Longmenshan Range based our observations of zonation, segmentation and composite evolutional processes during the Late Triassic superimposed by development of the differen- tial uplift and cooling processes that shows southern segments of the Longmenshan Range during Post-Jurassic times.展开更多
In the Central Orogenic Belt, China, two UHP metamorphic belts are discriminated mainly based on a detailed structural analysis of the Kanfenggou UHP metamorphic fragment exposed in the eastern Qinling orogen, and tog...In the Central Orogenic Belt, China, two UHP metamorphic belts are discriminated mainly based on a detailed structural analysis of the Kanfenggou UHP metamorphic fragment exposed in the eastern Qinling orogen, and together with previous regional structural, petrological and geochronological data at the scale of the orogenic domain. The first one corresponds to the South Altun North Qaidam North Qinling UHP metamorphic belt. The other is the Dabie Sulu UHP and HP metamorphic belts. The two UHP metamorphic belts are separated by a series of tectonic slices composed by the Qinling rock group, Danfeng rock group and Liuling or Foziling rock group etc. respectively, and are different in age of the peak UHP metamorphism and geodynamic implications for continental deep subduction and collision. Regional field and petrological relationships suggest that the Kanfenggou UHP metamorphic fragment that contains a large volume of the coesite and microdiamond bearing eclogite lenses is compatible with the structures recognized in the South Altun and North Qaidam UHP metamorphic fragments exposed in the western part of China, thereby forming a large UHP metamorphic belt up to 1 000 km long along the orogen strike. This UHP metamorphic belt represents an intercontinental deep subduction and collision belt between the Yangtze and Sino Korean cratons, occurred during the Paleozoic. On the other hand, the well constrained Dabie Sulu UHP and HP metamorphic belts occurred mainly during Triassic time (250-220 Ma), and were produced by the intracontinental deep subduction and collision within the Yangtze craton. The Kanfenggou UHP metamorphic fragment does not appear to link with the Dabie Sulu UHP and HP metamorphic belts along the orogen. There is no reason to assume the two UHP metamorphic belts as a single giant deep subduction and collision zone in the Central Orogenic Belt situated between the Yangtze and Sino Korean cratons. Therefore, any dynamic model for the orogen must account for the development of UHP metamorphic展开更多
The genus Lactarius Pers.(Russulales)is a cosmopolitan group of Basidiomycota that forms ectomycorrhizal relationships primarily with both deciduous and coniferous trees.Although the genus has been well-studied in Eur...The genus Lactarius Pers.(Russulales)is a cosmopolitan group of Basidiomycota that forms ectomycorrhizal relationships primarily with both deciduous and coniferous trees.Although the genus has been well-studied in Europe and North America,only fragmentary researches have been carried out on Asian species.In particular,the distribution of Lactarius species in South Korea is poorly understood due to insufficient morphological descriptions and a lack of DNA sequence data.In addition,the misuse of European and North American names has added to confusion regarding the taxonomy of Asian Lactarius species.In this study,the diversity of Lactarius in South Korea was evaluated by employing both morphological and phylogenetic approaches.A multi-locus phylogenetic analysis of 729 Lactarius specimens collected between 1960 and 2017 was performed using the internal transcribed spacer(ITS)region,partial nuclear ribosomal large subunit(nrLSU),partial second largest subunit of RNA polymerase II(rpb2),and minichromosome maintenance complex component 7(mcm7).49 Lactarius species were identified in three Lactarius subgenera:L.subg.Russularia(17 spp.),L.subg.Lactarius(22 spp.),and L.subg.Plinthogalus(10 spp.).Among them,28 Lactarius species were identified as new to science,while just 17 were previously described Lactarius species.Four of the taxa remain un-named due to paucity of materials.A key to Korean Lactarius species,molecular phylogenies,a summary of diversity,and detailed description are provided.展开更多
Salmonella Corvallis ST1541 has recently emerged as a globally disseminated pathogenic strain that often causes severe food-borne infections.Unlike most pandemic serotypes of Salmonella,the ST1541 strains harbored Col...Salmonella Corvallis ST1541 has recently emerged as a globally disseminated pathogenic strain that often causes severe food-borne infections.Unlike most pandemic serotypes of Salmonella,the ST1541 strains harbored ColRNA1 plasmids that contain qnr-like determinants known to be responsible for the increasing incidence of ciprofloxacin-resistant food-borne Salmonella infections.In this study,we conducted a genomic analysis of a global collection of 388 S.Corvallis ST1541 strains collected within a twenty-year period.We investigated the genetic characteristics of plasmid-mediated quinolone resistance(PMQR)plasmids harbored by these S.Corvallis strains,established a mini-mum spanning tree(MST)to determine the temporal and spatial distribution of the top 10 MST clusters,inferred a time-phylogenies for the major sub-lineages and traced the routes of international dissemination of this serotype strains.Bayesian algorithm predicted that UK might be the origin of S.Corvallis strains currently prevalent in various countries.This idea is supported by the observation of the emergence of intercontinental-disseminated clonal strains and extensive transmission of the extensive-drug resistance(XDR)-encoding plasmid pSA663.This study there-fore provides valuable insight into the evolution of globally transmitted S.Corvallis strains and suggests a need to strengthen cooperation between different countries to control the dissemination of these drug-resistant bacteria.展开更多
The evolution of coronavirus disease(COVID-19)into a pandemic has severely hampered the usage of public transit systems.In a post-COVID-19 world,we may see an increased reliance on autonomous cars and personal rapid t...The evolution of coronavirus disease(COVID-19)into a pandemic has severely hampered the usage of public transit systems.In a post-COVID-19 world,we may see an increased reliance on autonomous cars and personal rapid transit(PRT)systems,with inherent physical distancing,over buses,trains and aircraft for intracity,intercity,and interstate travel.However,air travel would continue to be the dominant mode of intercontinental transportation for humans.In this study,we perform a comprehensive computational analysis,using ANSYS Fluent,of typical intercontinental aircraft ventilation systems to determine the seat where environmental factors are most conducive to human comfort with regards to air quality,protection from orally or nasally released pollutants such as CO_(2)and coronavirus,and thermal comfort levels.Air velocity,temperature,and air pollutant concentration emitted from the nose/mouth of fellow travelers are considered for both Boeing and Airbus planes.In each plane,first class,business class,and economy class sections were analyzed.We present conclusions as to which is the optimum seat in each section of each plane and provide the data of the environmental conditions to support our inferences.The findings may be used by the general public to decide which seat to occupy for their next intercontinental flight.Alternatively,the commercial airliners can use such a model to plan the occupancy of the aircraft on long-duration intercontinental flights(viz.,Airbus A380 and Boeing B747).展开更多
The maximum flooding event and condensed section are one hot subject in modern se-quence stratigraphy and cyclic stratigraphy. Condensed section (CS)is defined as very thinabyssal or bathyal facies stratigraphic unit,...The maximum flooding event and condensed section are one hot subject in modern se-quence stratigraphy and cyclic stratigraphy. Condensed section (CS)is defined as very thinabyssal or bathyal facies stratigraphic unit, with extremely low rate of sedimentation andbroad extension at the maximum flooding age. It is an important indicator fordetermination of the maximum flooding event. In recent years, the coneeption ofcondensed section has been opened up in not only its formation depth but also thedistributive scope after the discovery of glauconitic CS in North China Platform inCambrian by the aothors, and the condensed section is defined as the low-rate marinestratigraphic unit formed at the maximum flooding stage. It is the key to age determinationand correlation of craton basinal sequence.展开更多
The construction of intercontinental power grid interconnection projects is key to realizing the vision of Global Energy Interconnection,which is to solve global energy problems in a clean and sustainable manner.These...The construction of intercontinental power grid interconnection projects is key to realizing the vision of Global Energy Interconnection,which is to solve global energy problems in a clean and sustainable manner.These projects may be influenced by a few factors that are neither technological nor economic,such as political,social,and international factors.This paper thus presents a multi-level model for recognizing which factor from a compiled list of 14 would impact a particular intercontinental interconnection project and for assessing the degree of the factor’s influence.In the first part of the model,the Analytic Hierarchy Process(AHP)method is used to recognize the project’s most significant impact factors.Using the recognition results,the second part of the model can assess the degree of the factor’s influence on the project based on ratings provided by experts.A comprehensive evaluation can thus be provided.As a case study,the proposed Saudi Arabia-Ethiopia power grid interconnection project connecting Asia and Africa was analyzed.Derived from a combination of multiple opinions from experts,evaluations from the model will be of direct benefit to decision-makers,investors,project implementers,and engineers,providing them with a deeper insight into the project.展开更多
The Model of Atmospheric Transport and Chemistry （MATCH） developed by the US National Center for Atmospheric Research （NCAR） was used to calculate the aerosol optical thickness （AOT） over China in 2006, with emi...The Model of Atmospheric Transport and Chemistry （MATCH） developed by the US National Center for Atmospheric Research （NCAR） was used to calculate the aerosol optical thickness （AOT） over China in 2006, with emission source data of the Intercontinental Chemical Transport Experiment Phase B （INTEX-B） and NCEP/NCAR reanalysis data as inputs. The simulation results of AOT were then validated with obser- vational data from the Moderate Resolution Imaging Spectroradiometer （MODIS）, Chinese Sun Hazemeter Network （CSHNET）, Aerosol Robotics Network （AERONET）, and China Aerosol Remote Sensing Network （CARSNET） at more than 30 stations over China. The comparison results indicated that the high values of AOT in the areas such as the Sichuan basin and East and South China and the low values of AOT over the Tibetan Plateau and Northwest and Northeast China were reasonably simulated by the MATCH. This model tended to underestimate the AOT values in high-aerosol-loading areas but overestimate the AOT val- ues in less polluted areas because there are still large uncertainties in the expression of emission sources, the description of the optical properties of aerosols, the treatment of cloud and precipitation, and the selection of grid resolution. The modeling results were consistent with the CSHNET, CARSNET, AERONET, and MODIS data in most parts of China, and the correlation coefficient of the monthly mean AOT between the model and the observation was 0.79 with CSHNET data at 23 stations, 0.51 with MODIS data, and 0.88 with data at 3 CARSNET stations and 2 other stations. All of them passed the significance test with c 〈 0.0001. The results demonstrated that the MATCH has the ability to simulate the characteristics of the AOT distribution and its seasonal variation over China.展开更多
As the big world hotel chains,Accor,InterContinental and Starwood Group took the different internationalization strategy to spread their hotels all over the world.This paper compared the strategies of them in the aspe...As the big world hotel chains,Accor,InterContinental and Starwood Group took the different internationalization strategy to spread their hotels all over the world.This paper compared the strategies of them in the aspect of location,chain developing,affiliation,innovation and operating.From the result of the comparison,other worldwide hotel chain groups could be suggested when they build their internationalization strategies.展开更多
A presumably mostly quadrupedal ankylopollexian iguanodontian, Bayannurosaurus perfectus gen. et sp. nov., is reported here, and is represented by an excellently well-preserved skeleton from the Lower Cretaceous Bayin...A presumably mostly quadrupedal ankylopollexian iguanodontian, Bayannurosaurus perfectus gen. et sp. nov., is reported here, and is represented by an excellently well-preserved skeleton from the Lower Cretaceous Bayingebi Formation of Inner Mongolia, China. The diagnosis of the taxon includes several autapomorphies, notably a dorsally directed, strap-like posterodorsal process of the jugal and a horizontally oriented preacetabular process of the ilium. The nearly complete caudal series retains eight posterior-most caudals with procoelous, trapezoidal centra in dorsal view, and the last three caudals are fully fused. The discovery ofB. perfectus opens a critical new window on the early evolution and intercontinental dispersal of lguanodontia. The skeleton displays a transitional morphology between nonbadrosauriform ankylopollexians and Hadrosauriformes. A phylogenetic analysis indicates that Bayannurosaurus is positioned higher on the tree than Hypselospinus, but below Ouranosaurus just outside of Hadrosauriformes. The tree topology of Iguanodontia with temporal and spatial constraints reveals a possible biogeographic scenario supported by the statistical dispersal-vicariance analysis： around the J/K boundary, non-hadrosauriform ankylopollexians experienced multiple dispersal events from Europe to Asia, accompanying the coeval fall of the global sea level.展开更多
Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghan...Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghana and Malaysia,thereby determining patterns and mechanisms that are common or unique to the regions.Methods Liana diversity,community structure and taxonomic composition were determined in 60 plots of 40×40 m2 in three forest types(primary,disturbed secondary,selectively logged)in each biogeo-graphic area.Two traits,climbing mechanisms and dispersal modes were determined for all species and individuals via direct field observation and with published literature.Data were analyzed at biogeographic(using combined forest data)and forest-type levels.Important Findings Both observed and rarefied-extrapolated species richness of lianas were significantly higher in Ghanaian forests compared to Malaysian forests.In most cases,species diversity indices(Shannon diversity index,Margalef,Fisher’s alpha)showed significantly higher liana diversity at Ghanaian forests at biogeographic and forest-type lev-els.Similarly,Ghanaian forests harbored significantly higher values of liana abundance and basal area than Malaysian forests at both biogeographic and forest-type levels.The taxonomic composition of lianas differed considerably between the two biogeographic areas at all levels,although similarity in composition increased at generic and family levels.Though above-ground biomass of lianas was simi-lar between the two biogeographic regions,variations occurred at forest-type level between the two regions.The two biogeographic areas showed some similarities in assemblages of liana climbing mechanisms.Although more species of lianas were adapted for animal dispersal than other dispersal modes in both countries,the majority of liana individuals in Ghana were wind dispersed whereas the majority of liana individuals in Malaysia were animal dispersed.We speculate that the differences in liana community assemblages between 展开更多
There is an increasing interest on the intercontinental transport of air pollution among the three main emission regions at northern mid-latitudes:North America,Europe,and East Asia.Air pollutants with sufficient long...There is an increasing interest on the intercontinental transport of air pollution among the three main emission regions at northern mid-latitudes:North America,Europe,and East Asia.Air pollutants with sufficient long lifetime can be transported from one continent to another.Observations from ground sites,aircraft and satellites have demonstrated this intercontinental-scale transport of air pollutants in the free troposphere.Numerical models have been applied to understand the pathways of the transport and the impact of intercontinental pollution transport.This paper reviews current observational evidence and modeling studies of intercontinental transport of ozone and its precursors,and the resulting impacts on air quality.展开更多
Maianthemum is a genus with more than 35 species from the tribe Polygonateae(Asparagaceae),widely distributed between North to Central Americas and eastern Asia with high diversity in the easternHimalayas to the Hengd...Maianthemum is a genus with more than 35 species from the tribe Polygonateae(Asparagaceae),widely distributed between North to Central Americas and eastern Asia with high diversity in the easternHimalayas to the Hengduan Mountains of SW China.Although most species from SW China form a well-supported clade,phylogenetic relationships within this clade remain unclear.With a broad level of taxon sampling and an extensive character sampling fromeight DNA regions,this study intends to revisit the phylogeny and biogeography of the genus to better understand the divergence patterns of species from SW China.Phylogenetic results suggested the monophyly of Maianthemum with recognition of nine strongly supported clades,but backbone relationships among these clades remained largely uncertain.For the SWChina clade,individuals from the same species are grouped into different lineages.Our results revealed that the fast radiation of the SWChina cladewas occurred in the eastern Himalayas,followed by subsequent radiation in the Hengduan Mountains in the Pliocene.Intercontinental disjunctions of Maianthemum in the Northern Hemisphere appear to have occurred multiple times during the late Miocene to the Pliocene,likely resulted by a combination of both vicariance and long-distance dispersal events.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41230313 and 40930424)
文摘ABSTRACT： The Longmenshan Range is a tectonically composite intracontinental orogen. Its structure, deformation and spatial evolution reflect multiple kinematic eposides and variable dynamics especially during Post-Middle to Post-Late Triassic time. Field work, lower-temperature thermochronological data and U-Pb detrital zircon ages indicate document down-dip zonation and along-strike segmentation dem- onstrated by significant differences in geological structure, intensity of deformation and deformation- involved strata, uplift and cooling processes. Low-temperature thermochronology and U-Pb detrital zir- con ages reveal a period of tectono-thermal quiescence with slow uplift and cooling during post Early Norian to Rhaetian orogeny, followed by rapid cooling and uplift during the Late Cenozoic accompanied by coeval southeastward thrusting and southwestward propagation of defromation. The Longmenshan Range formed by S-N striking compression exerted by the Qinling orogen, E-W striking compression by the Tibetan Plateau and SE-striking compression by the Yangtze Plate. We propose a southwestward propagation model for the Longmenshan Range based our observations of zonation, segmentation and composite evolutional processes during the Late Triassic superimposed by development of the differen- tial uplift and cooling processes that shows southern segments of the Longmenshan Range during Post-Jurassic times.
文摘In the Central Orogenic Belt, China, two UHP metamorphic belts are discriminated mainly based on a detailed structural analysis of the Kanfenggou UHP metamorphic fragment exposed in the eastern Qinling orogen, and together with previous regional structural, petrological and geochronological data at the scale of the orogenic domain. The first one corresponds to the South Altun North Qaidam North Qinling UHP metamorphic belt. The other is the Dabie Sulu UHP and HP metamorphic belts. The two UHP metamorphic belts are separated by a series of tectonic slices composed by the Qinling rock group, Danfeng rock group and Liuling or Foziling rock group etc. respectively, and are different in age of the peak UHP metamorphism and geodynamic implications for continental deep subduction and collision. Regional field and petrological relationships suggest that the Kanfenggou UHP metamorphic fragment that contains a large volume of the coesite and microdiamond bearing eclogite lenses is compatible with the structures recognized in the South Altun and North Qaidam UHP metamorphic fragments exposed in the western part of China, thereby forming a large UHP metamorphic belt up to 1 000 km long along the orogen strike. This UHP metamorphic belt represents an intercontinental deep subduction and collision belt between the Yangtze and Sino Korean cratons, occurred during the Paleozoic. On the other hand, the well constrained Dabie Sulu UHP and HP metamorphic belts occurred mainly during Triassic time (250-220 Ma), and were produced by the intracontinental deep subduction and collision within the Yangtze craton. The Kanfenggou UHP metamorphic fragment does not appear to link with the Dabie Sulu UHP and HP metamorphic belts along the orogen. There is no reason to assume the two UHP metamorphic belts as a single giant deep subduction and collision zone in the Central Orogenic Belt situated between the Yangtze and Sino Korean cratons. Therefore, any dynamic model for the orogen must account for the development of UHP metamorphic
基金supported by the project on the survey and excavation of Korean indigenous species of the National Institute of Biological Resources(NIBR 201701104 and NIBR 201801105)under the Ministry of Environment of the Republic of Korea.
文摘The genus Lactarius Pers.(Russulales)is a cosmopolitan group of Basidiomycota that forms ectomycorrhizal relationships primarily with both deciduous and coniferous trees.Although the genus has been well-studied in Europe and North America,only fragmentary researches have been carried out on Asian species.In particular,the distribution of Lactarius species in South Korea is poorly understood due to insufficient morphological descriptions and a lack of DNA sequence data.In addition,the misuse of European and North American names has added to confusion regarding the taxonomy of Asian Lactarius species.In this study,the diversity of Lactarius in South Korea was evaluated by employing both morphological and phylogenetic approaches.A multi-locus phylogenetic analysis of 729 Lactarius specimens collected between 1960 and 2017 was performed using the internal transcribed spacer(ITS)region,partial nuclear ribosomal large subunit(nrLSU),partial second largest subunit of RNA polymerase II(rpb2),and minichromosome maintenance complex component 7(mcm7).49 Lactarius species were identified in three Lactarius subgenera:L.subg.Russularia(17 spp.),L.subg.Lactarius(22 spp.),and L.subg.Plinthogalus(10 spp.).Among them,28 Lactarius species were identified as new to science,while just 17 were previously described Lactarius species.Four of the taxa remain un-named due to paucity of materials.A key to Korean Lactarius species,molecular phylogenies,a summary of diversity,and detailed description are provided.
基金supported by the Key Research and Development Program of Guangdong Province(Grant number,2022B1111040002)the Collaborative Research Fund from Research Grant Council of the Government of Hong Kong SAR(Grant numbers,C7147-20G,C7003-20G).
文摘Salmonella Corvallis ST1541 has recently emerged as a globally disseminated pathogenic strain that often causes severe food-borne infections.Unlike most pandemic serotypes of Salmonella,the ST1541 strains harbored ColRNA1 plasmids that contain qnr-like determinants known to be responsible for the increasing incidence of ciprofloxacin-resistant food-borne Salmonella infections.In this study,we conducted a genomic analysis of a global collection of 388 S.Corvallis ST1541 strains collected within a twenty-year period.We investigated the genetic characteristics of plasmid-mediated quinolone resistance(PMQR)plasmids harbored by these S.Corvallis strains,established a mini-mum spanning tree(MST)to determine the temporal and spatial distribution of the top 10 MST clusters,inferred a time-phylogenies for the major sub-lineages and traced the routes of international dissemination of this serotype strains.Bayesian algorithm predicted that UK might be the origin of S.Corvallis strains currently prevalent in various countries.This idea is supported by the observation of the emergence of intercontinental-disseminated clonal strains and extensive transmission of the extensive-drug resistance(XDR)-encoding plasmid pSA663.This study there-fore provides valuable insight into the evolution of globally transmitted S.Corvallis strains and suggests a need to strengthen cooperation between different countries to control the dissemination of these drug-resistant bacteria.
文摘The evolution of coronavirus disease(COVID-19)into a pandemic has severely hampered the usage of public transit systems.In a post-COVID-19 world,we may see an increased reliance on autonomous cars and personal rapid transit(PRT)systems,with inherent physical distancing,over buses,trains and aircraft for intracity,intercity,and interstate travel.However,air travel would continue to be the dominant mode of intercontinental transportation for humans.In this study,we perform a comprehensive computational analysis,using ANSYS Fluent,of typical intercontinental aircraft ventilation systems to determine the seat where environmental factors are most conducive to human comfort with regards to air quality,protection from orally or nasally released pollutants such as CO_(2)and coronavirus,and thermal comfort levels.Air velocity,temperature,and air pollutant concentration emitted from the nose/mouth of fellow travelers are considered for both Boeing and Airbus planes.In each plane,first class,business class,and economy class sections were analyzed.We present conclusions as to which is the optimum seat in each section of each plane and provide the data of the environmental conditions to support our inferences.The findings may be used by the general public to decide which seat to occupy for their next intercontinental flight.Alternatively,the commercial airliners can use such a model to plan the occupancy of the aircraft on long-duration intercontinental flights(viz.,Airbus A380 and Boeing B747).
基金Subject supported by the National Natural Science Foundation of China, Royal Society of UK and China Association for Science and Technology.
文摘The maximum flooding event and condensed section are one hot subject in modern se-quence stratigraphy and cyclic stratigraphy. Condensed section (CS)is defined as very thinabyssal or bathyal facies stratigraphic unit, with extremely low rate of sedimentation andbroad extension at the maximum flooding age. It is an important indicator fordetermination of the maximum flooding event. In recent years, the coneeption ofcondensed section has been opened up in not only its formation depth but also thedistributive scope after the discovery of glauconitic CS in North China Platform inCambrian by the aothors, and the condensed section is defined as the low-rate marinestratigraphic unit formed at the maximum flooding stage. It is the key to age determinationand correlation of craton basinal sequence.
基金supported by the State Grid Science and Technology Project“Research on Method and Evaluation Principle for the Cross-Continent Power Transmission Planning Scheme”(SGTYHT/16-JS-198)。
文摘The construction of intercontinental power grid interconnection projects is key to realizing the vision of Global Energy Interconnection,which is to solve global energy problems in a clean and sustainable manner.These projects may be influenced by a few factors that are neither technological nor economic,such as political,social,and international factors.This paper thus presents a multi-level model for recognizing which factor from a compiled list of 14 would impact a particular intercontinental interconnection project and for assessing the degree of the factor’s influence.In the first part of the model,the Analytic Hierarchy Process(AHP)method is used to recognize the project’s most significant impact factors.Using the recognition results,the second part of the model can assess the degree of the factor’s influence on the project based on ratings provided by experts.A comprehensive evaluation can thus be provided.As a case study,the proposed Saudi Arabia-Ethiopia power grid interconnection project connecting Asia and Africa was analyzed.Derived from a combination of multiple opinions from experts,evaluations from the model will be of direct benefit to decision-makers,investors,project implementers,and engineers,providing them with a deeper insight into the project.
基金Supported by the National Basic Research and Development (973) Program of China (2012CB955303 and 2011CB403405)National Science and Technology Support Program of China (2007BAC03A01)+1 种基金Chinese Academy of Meteorological Sciences Basic Research Project (2012Y003)Tianjin Municipal Meteorological Bureau Research Program (201210)
文摘The Model of Atmospheric Transport and Chemistry （MATCH） developed by the US National Center for Atmospheric Research （NCAR） was used to calculate the aerosol optical thickness （AOT） over China in 2006, with emission source data of the Intercontinental Chemical Transport Experiment Phase B （INTEX-B） and NCEP/NCAR reanalysis data as inputs. The simulation results of AOT were then validated with obser- vational data from the Moderate Resolution Imaging Spectroradiometer （MODIS）, Chinese Sun Hazemeter Network （CSHNET）, Aerosol Robotics Network （AERONET）, and China Aerosol Remote Sensing Network （CARSNET） at more than 30 stations over China. The comparison results indicated that the high values of AOT in the areas such as the Sichuan basin and East and South China and the low values of AOT over the Tibetan Plateau and Northwest and Northeast China were reasonably simulated by the MATCH. This model tended to underestimate the AOT values in high-aerosol-loading areas but overestimate the AOT val- ues in less polluted areas because there are still large uncertainties in the expression of emission sources, the description of the optical properties of aerosols, the treatment of cloud and precipitation, and the selection of grid resolution. The modeling results were consistent with the CSHNET, CARSNET, AERONET, and MODIS data in most parts of China, and the correlation coefficient of the monthly mean AOT between the model and the observation was 0.79 with CSHNET data at 23 stations, 0.51 with MODIS data, and 0.88 with data at 3 CARSNET stations and 2 other stations. All of them passed the significance test with c 〈 0.0001. The results demonstrated that the MATCH has the ability to simulate the characteristics of the AOT distribution and its seasonal variation over China.
文摘As the big world hotel chains,Accor,InterContinental and Starwood Group took the different internationalization strategy to spread their hotels all over the world.This paper compared the strategies of them in the aspect of location,chain developing,affiliation,innovation and operating.From the result of the comparison,other worldwide hotel chain groups could be suggested when they build their internationalization strategies.
基金supported by the Beijing Natural Science Foundation(5174032)the National Natural Science Foundation of China(41688103,41120124002,91514302 and 41602006)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB18030504)the Youth Backbone Training Plan(201601)Overseas Talents Attracting Program(OTP-2018-001)Innovative Team Program(IG201705N)of the Beijing Academy of Science and Technologythe Beijing Millions of Talents Project in the New Century and the Department of Land and Resources of Inner Mongolia
文摘A presumably mostly quadrupedal ankylopollexian iguanodontian, Bayannurosaurus perfectus gen. et sp. nov., is reported here, and is represented by an excellently well-preserved skeleton from the Lower Cretaceous Bayingebi Formation of Inner Mongolia, China. The diagnosis of the taxon includes several autapomorphies, notably a dorsally directed, strap-like posterodorsal process of the jugal and a horizontally oriented preacetabular process of the ilium. The nearly complete caudal series retains eight posterior-most caudals with procoelous, trapezoidal centra in dorsal view, and the last three caudals are fully fused. The discovery ofB. perfectus opens a critical new window on the early evolution and intercontinental dispersal of lguanodontia. The skeleton displays a transitional morphology between nonbadrosauriform ankylopollexians and Hadrosauriformes. A phylogenetic analysis indicates that Bayannurosaurus is positioned higher on the tree than Hypselospinus, but below Ouranosaurus just outside of Hadrosauriformes. The tree topology of Iguanodontia with temporal and spatial constraints reveals a possible biogeographic scenario supported by the statistical dispersal-vicariance analysis： around the J/K boundary, non-hadrosauriform ankylopollexians experienced multiple dispersal events from Europe to Asia, accompanying the coeval fall of the global sea level.
基金We gratefully acknowledge the support of TWAS-USM Postgraduate Fellowship and Research University Grant(RU)(1001/PBIOLOGI/815086).
文摘Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghana and Malaysia,thereby determining patterns and mechanisms that are common or unique to the regions.Methods Liana diversity,community structure and taxonomic composition were determined in 60 plots of 40×40 m2 in three forest types(primary,disturbed secondary,selectively logged)in each biogeo-graphic area.Two traits,climbing mechanisms and dispersal modes were determined for all species and individuals via direct field observation and with published literature.Data were analyzed at biogeographic(using combined forest data)and forest-type levels.Important Findings Both observed and rarefied-extrapolated species richness of lianas were significantly higher in Ghanaian forests compared to Malaysian forests.In most cases,species diversity indices(Shannon diversity index,Margalef,Fisher’s alpha)showed significantly higher liana diversity at Ghanaian forests at biogeographic and forest-type lev-els.Similarly,Ghanaian forests harbored significantly higher values of liana abundance and basal area than Malaysian forests at both biogeographic and forest-type levels.The taxonomic composition of lianas differed considerably between the two biogeographic areas at all levels,although similarity in composition increased at generic and family levels.Though above-ground biomass of lianas was simi-lar between the two biogeographic regions,variations occurred at forest-type level between the two regions.The two biogeographic areas showed some similarities in assemblages of liana climbing mechanisms.Although more species of lianas were adapted for animal dispersal than other dispersal modes in both countries,the majority of liana individuals in Ghana were wind dispersed whereas the majority of liana individuals in Malaysia were animal dispersed.We speculate that the differences in liana community assemblages between
文摘There is an increasing interest on the intercontinental transport of air pollution among the three main emission regions at northern mid-latitudes:North America,Europe,and East Asia.Air pollutants with sufficient long lifetime can be transported from one continent to another.Observations from ground sites,aircraft and satellites have demonstrated this intercontinental-scale transport of air pollutants in the free troposphere.Numerical models have been applied to understand the pathways of the transport and the impact of intercontinental pollution transport.This paper reviews current observational evidence and modeling studies of intercontinental transport of ozone and its precursors,and the resulting impacts on air quality.
基金This study was supported by grants from Natural Sciences Foundation of China(31760055)Natural Sciences Foundation of Hunan Province(2019JJ40232 and 2019JJ40233)+2 种基金Comprehensive Scientific Investigation of Biodiversity from the Wuling Mountains(2014FY110100)the Hunan Provincial Innovation Foundation for Postgraduate(CX2018B724)the John D.and Catherine T.MacArthur Foundation.
文摘Maianthemum is a genus with more than 35 species from the tribe Polygonateae(Asparagaceae),widely distributed between North to Central Americas and eastern Asia with high diversity in the easternHimalayas to the Hengduan Mountains of SW China.Although most species from SW China form a well-supported clade,phylogenetic relationships within this clade remain unclear.With a broad level of taxon sampling and an extensive character sampling fromeight DNA regions,this study intends to revisit the phylogeny and biogeography of the genus to better understand the divergence patterns of species from SW China.Phylogenetic results suggested the monophyly of Maianthemum with recognition of nine strongly supported clades,but backbone relationships among these clades remained largely uncertain.For the SWChina clade,individuals from the same species are grouped into different lineages.Our results revealed that the fast radiation of the SWChina cladewas occurred in the eastern Himalayas,followed by subsequent radiation in the Hengduan Mountains in the Pliocene.Intercontinental disjunctions of Maianthemum in the Northern Hemisphere appear to have occurred multiple times during the late Miocene to the Pliocene,likely resulted by a combination of both vicariance and long-distance dispersal events.
