The research proposal has the following scope. In relation to the general objective, the aim is to model the evolution of the climate crisis over time taking as variables global warming, greenhouse gases, atmospheric ...The research proposal has the following scope. In relation to the general objective, the aim is to model the evolution of the climate crisis over time taking as variables global warming, greenhouse gases, atmospheric temperature and ocean temperature, as well as the continuity of the natural phenomena in terms of their measurement, temporality and projection. To achieve the above, the description of the following specific objectives is proposed: - Identify the variables corresponding to the climate crisis, their relationship and correlation between them;- Develop projection models with mathematical and statistical arrangements to project them in a given time and, in this way, - Propose mitigation measures for different unfavorable scenarios. The main variables that are currently directly linked to Climate Change are: CO<sub>2</sub>, the atmospheric index, precipitation, temperature and wind speed. The correlation that exists between climatic elements is very high, both in historical behavior and projected behavior for 2035, their correlation is estimated at 0.90, 0.95, 0.93 and 91 respectively. The mathematical models used to manipulate the historical and projected analysis of the variables studied: are the normal arrangements, this ensures that the values can be used on a common scale;Then there is the analysis of the historical variables using the linear trend, and finally there is the analysis of the variables projected to the year 2035 using the polynomial trend. In both situations, the direct relationship of greenhouse gases, mainly CO<sub>2</sub>, is directly related to the variations of the variables over time, which is a very worrying result because we can no longer talk about climate change, but rather about CLIMATE CRISIS. To a large extent, a change in the paradigm of exploitation of the resources of our mother earth is required. Alert in an SOS manner to the great powers, which make reasonable use of technology, for this attenuation measures are proposed.展开更多
Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanism...Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods.Therefore,it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle.Based on the data of climate elements(sunshine hours,precipitation and temperature),human activities(population intensity and GDP intensity)and other natural factors(altitude,slope and aspect),this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method,a trend analysis,and a gravity center model,and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model.The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest.During 1981-2019,the temporal variation of vegetation NDVI showed an overall increasing trend.The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County,Gansu Province,and the center moved northeastwards from 1981 to 2019.During 1981-2000 and 2001-2019,the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest.During the study period(1981-2019),the dominant factors influencing vegetation NDVI shifted from natural factors to human activities.These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin.展开更多
Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variab...Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.展开更多
The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to cli...The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate.展开更多
[Objective] The aim was to study the environment evolution of Shanbei Loess landscape under the background of global climate changes.[Method] The annual and monthly temperature and precipitation in Yulin area in north...[Objective] The aim was to study the environment evolution of Shanbei Loess landscape under the background of global climate changes.[Method] The annual and monthly temperature and precipitation in Yulin area in north Shaanxi from 1952 to 2009 were selected,and by dint of linear regression and M-K mutation,the Loess land form evolution under the global climate change was studied.[Result] The temperature in Yulin area showed increasing tendency from 1952 to 2009 at a speed of 0.287℃/10 a.The year 1994 was a year of mutation of temperature;precipitation decreased at speed of 8.262 mm/10 a and the precipitation fluctuated largely in 1960s,and stably in 1970s,1980s and 1990s.It showed drying tendency.The climate in north Shanxi was becoming warmer.The extreme dry and flood incident,especially the rising drought occurrence frequency had more serious endangerment to the fragile ecological environment.The " warmer drought" of climate worsened the environment in north Shaanxi,with temperature rising and worsening drought;reduction of precipitation made the wind and sand more active;the frequency of sandstorm increased;desertification of land furthered;the water and soil losses in Loess was serious and might led to degradation of land in north Shaanxi.[Conclusion] The study provided theoretical basis for the ecological and environmental construction in the region.展开更多
Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bio...Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bioinformatic and transgenic plant analyses,we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis.We refer to the CKXs retaining evolutionarily ancient characteristics as“ancient CKXs”and those that have expanded and functionally diverged in angiosperms as“non-ancient CKXs”.We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis,while the ancient CKX(AtCKX7)is not drought responsive.Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth.Previous mutant studies have shown that non-ancient CKXs regulate organ development,particularly that of flowers.Furthermore,ancient CKXs preferentially degrade cis-zeatin(cZ)-type cytokinins,while non-ancient CKXs preferentially target N6-(Δ2-isopentenyl)adenines(iPs)and trans-zeatins(tZs).Based on the results of this work,an accompanying study(Wang et al.https://doi.org/10.1038/s41438-019-0211-x)and previous studies,we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses,while ancient CKXs and their preferred substrates of cZs play a housekeeping role,which echoes the conclusions and hypothesis described in the accompanying report(Wang,X.et al.Evolution and roles of cytokinin genes in angiosperms 1:Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?Hortic Res 7,(2020).https://doi.org/10.1038/s41438-019-0211-x).展开更多
Significant changes in water cycle elements/processes have created serious challenges to regional sustainability and high-quality development in the Yellow River Basin in China.It is necessary to investigate the impac...Significant changes in water cycle elements/processes have created serious challenges to regional sustainability and high-quality development in the Yellow River Basin in China.It is necessary to investigate the impacts of climate change and human activities on hydrological evolution and disaster risk from a holistic perspective of the basin.This study developed initiatives to clarify the mechanisms of hydrological evolution in the human-influenced Yellow River Basin.The proposed research method includes:(1)a tool to simulate multiple factors and a multi-scale water cycle using a grid-based spatiotemporal coupling approach,and(2)a new algorithm to separate the responses of the water cycle to climate change and human impacts,and de-couple the eco-environmental effects using artificial intelligence techniques.With this research framework,key breakthroughs are expected to be made in the understanding of the impacts of land cover change on the water cycle and blue/green water redirection.The outcomes of this research project are expected to provide theoretical support for ecological protection and water governance in the basin.展开更多
Based on the data of historical geography, the analysis of the stratigraphic section, and the textual research of place names and satellite photographic interpretations, the authors study the formation and evolution o...Based on the data of historical geography, the analysis of the stratigraphic section, and the textual research of place names and satellite photographic interpretations, the authors study the formation and evolution of ancient lakes on the south coast plain of Laizhou Bay where there were once three lakes: Judian Lake, Qingshuibo Lake and Biehua Lake. All the lakes formed 6000 years ago evolved from the lagoons near the estuary and went through two periods, the golden age in the Middle Holocene and the shrinking age in the Late Holocene. The disappearance of the lakes resulted from the drying climate, the migration of the river courses and the activities of human beings. Among the three reasons, the migration of the river courses is the main one.展开更多
Ancient Chinese pavilion refers to the building called "pavilion" before the Republic of China. It is a traditional building with Chinese characteristics. Ancient Chinese pavilion is not only the classical a...Ancient Chinese pavilion refers to the building called "pavilion" before the Republic of China. It is a traditional building with Chinese characteristics. Ancient Chinese pavilion is not only the classical architecture in Chinese landscape architecture, but also the symbolic literary image in the history of Chinese literature. The related research on ancient Chinese pavilion in the field of architecture is mainly carried out from the aspects of architectural modeling, structure construction, spatial mood, etc. and there is little research on the function evolution of ancient Chinese pavilion. Based on the perspective of literature and history, this paper studied the original function and evolution history of ancient pavilion in China from the perspectives of philology, history and literature.展开更多
Imperial city and outer city are the most important differentiation of the spatial structure of ancient Chinese capitals.The relationship between city and Guo changed from the original spatial structure mode of "...Imperial city and outer city are the most important differentiation of the spatial structure of ancient Chinese capitals.The relationship between city and Guo changed from the original spatial structure mode of "respecting the west" and "sitting in the west and facing the east" to the spatial structure mode of "sitting in the north and facing the south" and the three outer cities in the east,south and west surrounding the imperial city after the Wei,Jin,Southern and Northern Dynasties,and gradually changed from the original "multi palace" system to the "single palace" system.Finally,a "heavy city" capital spatial structure with the outer city around the imperial city and the imperial city around the palace city,and the central axis of the chessboard format was formed.During the Tang and Song Dynasties,it was a period of great change in the history of feudal society in China.Through the investigation of the evolution characteristics of the spatial form of capital cities in the Tang and Song Dynasties,the track of the transformation of social ideology,political system,economic structure and many other fields in the Tang and Song Dynasties was made clear.展开更多
Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration a...Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.展开更多
In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This s...In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This study proposes a contribution to the analysis of the evolution of agro-climatic risks in the context of climate variability. Some statistical tests are used on the main variables of the rainy season to determine the trends and the variabilities described by the data series. Thus, the paper provides a statistical modeling of the different agro-climatic risks while the seasonal variability of agro-climatic parameters was analyzed as well as their inter annual variability. The study identifies the probability distributions of agroclimatic risks and the characterization of the rainy season was clarified.展开更多
文摘The research proposal has the following scope. In relation to the general objective, the aim is to model the evolution of the climate crisis over time taking as variables global warming, greenhouse gases, atmospheric temperature and ocean temperature, as well as the continuity of the natural phenomena in terms of their measurement, temporality and projection. To achieve the above, the description of the following specific objectives is proposed: - Identify the variables corresponding to the climate crisis, their relationship and correlation between them;- Develop projection models with mathematical and statistical arrangements to project them in a given time and, in this way, - Propose mitigation measures for different unfavorable scenarios. The main variables that are currently directly linked to Climate Change are: CO<sub>2</sub>, the atmospheric index, precipitation, temperature and wind speed. The correlation that exists between climatic elements is very high, both in historical behavior and projected behavior for 2035, their correlation is estimated at 0.90, 0.95, 0.93 and 91 respectively. The mathematical models used to manipulate the historical and projected analysis of the variables studied: are the normal arrangements, this ensures that the values can be used on a common scale;Then there is the analysis of the historical variables using the linear trend, and finally there is the analysis of the variables projected to the year 2035 using the polynomial trend. In both situations, the direct relationship of greenhouse gases, mainly CO<sub>2</sub>, is directly related to the variations of the variables over time, which is a very worrying result because we can no longer talk about climate change, but rather about CLIMATE CRISIS. To a large extent, a change in the paradigm of exploitation of the resources of our mother earth is required. Alert in an SOS manner to the great powers, which make reasonable use of technology, for this attenuation measures are proposed.
基金This work was supported by grants from the National Natural Science Foundation of China(42101306,4217107)the Natural Science Foundation of Shandong Province(ZR2021MD047),the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA2002040203)+2 种基金the Open Fund of the Key Laboratory of National Geographic Census and Monitoring,Ministry of Natural Resources(MNR)(2020NGCM02)the Open Fund of the Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources(KF-2020-05-001)the Major Project of the High Resolution Earth Observation System of China(GFZX0404130304).
文摘Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods.Therefore,it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle.Based on the data of climate elements(sunshine hours,precipitation and temperature),human activities(population intensity and GDP intensity)and other natural factors(altitude,slope and aspect),this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method,a trend analysis,and a gravity center model,and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model.The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest.During 1981-2019,the temporal variation of vegetation NDVI showed an overall increasing trend.The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County,Gansu Province,and the center moved northeastwards from 1981 to 2019.During 1981-2000 and 2001-2019,the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest.During the study period(1981-2019),the dominant factors influencing vegetation NDVI shifted from natural factors to human activities.These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin.
文摘Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.
基金by the Chinese National Natural Science Foundation (40971005)
文摘The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate.
文摘[Objective] The aim was to study the environment evolution of Shanbei Loess landscape under the background of global climate changes.[Method] The annual and monthly temperature and precipitation in Yulin area in north Shaanxi from 1952 to 2009 were selected,and by dint of linear regression and M-K mutation,the Loess land form evolution under the global climate change was studied.[Result] The temperature in Yulin area showed increasing tendency from 1952 to 2009 at a speed of 0.287℃/10 a.The year 1994 was a year of mutation of temperature;precipitation decreased at speed of 8.262 mm/10 a and the precipitation fluctuated largely in 1960s,and stably in 1970s,1980s and 1990s.It showed drying tendency.The climate in north Shanxi was becoming warmer.The extreme dry and flood incident,especially the rising drought occurrence frequency had more serious endangerment to the fragile ecological environment.The " warmer drought" of climate worsened the environment in north Shaanxi,with temperature rising and worsening drought;reduction of precipitation made the wind and sand more active;the frequency of sandstorm increased;desertification of land furthered;the water and soil losses in Loess was serious and might led to degradation of land in north Shaanxi.[Conclusion] The study provided theoretical basis for the ecological and environmental construction in the region.
基金supported by the National Natural Science Foundation of China[grant number 31471860 to J.D.and number 31401842 to H.W.]the Open Project of the State Key Laboratory of Crop Genetics and Germplasm Enhancement[grant number ZW2014008 to H.W.].
文摘Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bioinformatic and transgenic plant analyses,we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis.We refer to the CKXs retaining evolutionarily ancient characteristics as“ancient CKXs”and those that have expanded and functionally diverged in angiosperms as“non-ancient CKXs”.We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis,while the ancient CKX(AtCKX7)is not drought responsive.Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth.Previous mutant studies have shown that non-ancient CKXs regulate organ development,particularly that of flowers.Furthermore,ancient CKXs preferentially degrade cis-zeatin(cZ)-type cytokinins,while non-ancient CKXs preferentially target N6-(Δ2-isopentenyl)adenines(iPs)and trans-zeatins(tZs).Based on the results of this work,an accompanying study(Wang et al.https://doi.org/10.1038/s41438-019-0211-x)and previous studies,we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses,while ancient CKXs and their preferred substrates of cZs play a housekeeping role,which echoes the conclusions and hypothesis described in the accompanying report(Wang,X.et al.Evolution and roles of cytokinin genes in angiosperms 1:Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?Hortic Res 7,(2020).https://doi.org/10.1038/s41438-019-0211-x).
基金supported by the National Natural Science Foundation of China(Grant No.U2243203),the Fundamental Research Funds for the Central Universities(Grants No.B200204029 and B220201011),and the Natural Science Foundation of Jiangsu Province(Grant No.BK20210368).
文摘Significant changes in water cycle elements/processes have created serious challenges to regional sustainability and high-quality development in the Yellow River Basin in China.It is necessary to investigate the impacts of climate change and human activities on hydrological evolution and disaster risk from a holistic perspective of the basin.This study developed initiatives to clarify the mechanisms of hydrological evolution in the human-influenced Yellow River Basin.The proposed research method includes:(1)a tool to simulate multiple factors and a multi-scale water cycle using a grid-based spatiotemporal coupling approach,and(2)a new algorithm to separate the responses of the water cycle to climate change and human impacts,and de-couple the eco-environmental effects using artificial intelligence techniques.With this research framework,key breakthroughs are expected to be made in the understanding of the impacts of land cover change on the water cycle and blue/green water redirection.The outcomes of this research project are expected to provide theoretical support for ecological protection and water governance in the basin.
基金Under the auspices of the NaturalFoundation of Shandong Province(Y2004E05).
文摘Based on the data of historical geography, the analysis of the stratigraphic section, and the textual research of place names and satellite photographic interpretations, the authors study the formation and evolution of ancient lakes on the south coast plain of Laizhou Bay where there were once three lakes: Judian Lake, Qingshuibo Lake and Biehua Lake. All the lakes formed 6000 years ago evolved from the lagoons near the estuary and went through two periods, the golden age in the Middle Holocene and the shrinking age in the Late Holocene. The disappearance of the lakes resulted from the drying climate, the migration of the river courses and the activities of human beings. Among the three reasons, the migration of the river courses is the main one.
文摘Ancient Chinese pavilion refers to the building called "pavilion" before the Republic of China. It is a traditional building with Chinese characteristics. Ancient Chinese pavilion is not only the classical architecture in Chinese landscape architecture, but also the symbolic literary image in the history of Chinese literature. The related research on ancient Chinese pavilion in the field of architecture is mainly carried out from the aspects of architectural modeling, structure construction, spatial mood, etc. and there is little research on the function evolution of ancient Chinese pavilion. Based on the perspective of literature and history, this paper studied the original function and evolution history of ancient pavilion in China from the perspectives of philology, history and literature.
文摘Imperial city and outer city are the most important differentiation of the spatial structure of ancient Chinese capitals.The relationship between city and Guo changed from the original spatial structure mode of "respecting the west" and "sitting in the west and facing the east" to the spatial structure mode of "sitting in the north and facing the south" and the three outer cities in the east,south and west surrounding the imperial city after the Wei,Jin,Southern and Northern Dynasties,and gradually changed from the original "multi palace" system to the "single palace" system.Finally,a "heavy city" capital spatial structure with the outer city around the imperial city and the imperial city around the palace city,and the central axis of the chessboard format was formed.During the Tang and Song Dynasties,it was a period of great change in the history of feudal society in China.Through the investigation of the evolution characteristics of the spatial form of capital cities in the Tang and Song Dynasties,the track of the transformation of social ideology,political system,economic structure and many other fields in the Tang and Song Dynasties was made clear.
基金The National Natural Science Foundation of China under contract Nos 42077410 and 41872112。
文摘Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.
文摘In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This study proposes a contribution to the analysis of the evolution of agro-climatic risks in the context of climate variability. Some statistical tests are used on the main variables of the rainy season to determine the trends and the variabilities described by the data series. Thus, the paper provides a statistical modeling of the different agro-climatic risks while the seasonal variability of agro-climatic parameters was analyzed as well as their inter annual variability. The study identifies the probability distributions of agroclimatic risks and the characterization of the rainy season was clarified.
