Vegetation phenology is an indicator of vegetation response to natural environmental changes and is of great significance for the study of global climate change and its impact on terrestrial ecosystems.The normalized ...Vegetation phenology is an indicator of vegetation response to natural environmental changes and is of great significance for the study of global climate change and its impact on terrestrial ecosystems.The normalized difference vegetation index(NDVI)and enhanced vegetation index(EVI),extracted from the Moderate Resolution Imaging Spectrometer(MODIS),are widely used to monitor phenology by calculating land surface reflectance.However,the applicability of the vegetation index based on‘greenness'to monitor photosynthetic activity is hindered by poor observation conditions(e.g.,ground shadows,snow,and clouds).Recently,satellite measurements of solar-induced chlorophyll fluorescence(SIF)from OCO-2 sensors have shown great potential for studying vegetation phenology.Here,we tested the feasibility of SIF in extracting phenological metrics in permafrost regions of the northeastern China,exploring the characteristics of SIF in the study of vegetation phenology and the differences between NDVI and EVI.The results show that NDVI has obvious SOS advance and EOS lag,and EVI is closer to SIF.The growing season length based on SIF is often the shortest,while it can represent the true phenology of vegetation because it is closely related to photosynthesis.SIF is more sensitive than the traditional remote sensing indices in monitoring seasonal changes in vegetation phenology and can compensate for the shortcomings of traditional vegetation indices.We also used the time series data of MODIS NDVI and EVI to extract phenological metrics in different permafrost regions.The results show that the length of growing season of vegetation in predominantly continuous permafrost(zone I)is longer than in permafrost with isolated taliks(zone II).Our results have certain significance for understanding the response of ecosystems in cold regions to global climate change.展开更多
中国人民形象的海外传播对中国大国形象构建具有重要的促进作用。基于态度系统理论框架,借助UAM Corpus Tool,对《习近平谈治国理政》及其英译本中的态度资源进行描述性统计分析和主题分析,发现原文与译文主要通过积极的判断资源评价和...中国人民形象的海外传播对中国大国形象构建具有重要的促进作用。基于态度系统理论框架,借助UAM Corpus Tool,对《习近平谈治国理政》及其英译本中的态度资源进行描述性统计分析和主题分析,发现原文与译文主要通过积极的判断资源评价和塑造中国人民形象,具体体现在创造力强、爱好和平、勤劳勇敢和自强不息4个方面。在整个译介过程中,译者以遵循准确性为首要原则,充分考虑汉英语言差异,灵活采用一词多译、句型调整、语义融合等多种翻译策略与方法来转换态度资源,以确保译文的接受效果,帮助国际受众更好地理解中国人民形象的具体内涵。文章通过翻译实例分析我国政治文本中中国人民形象英译现状,以期为外宣翻译实践和研究提供有益镜鉴。展开更多
基金Under the auspices of National Key Research and Development Projects(No.2018YFE0207800)National Natural Science Foundation of China(No.41871103)。
文摘Vegetation phenology is an indicator of vegetation response to natural environmental changes and is of great significance for the study of global climate change and its impact on terrestrial ecosystems.The normalized difference vegetation index(NDVI)and enhanced vegetation index(EVI),extracted from the Moderate Resolution Imaging Spectrometer(MODIS),are widely used to monitor phenology by calculating land surface reflectance.However,the applicability of the vegetation index based on‘greenness'to monitor photosynthetic activity is hindered by poor observation conditions(e.g.,ground shadows,snow,and clouds).Recently,satellite measurements of solar-induced chlorophyll fluorescence(SIF)from OCO-2 sensors have shown great potential for studying vegetation phenology.Here,we tested the feasibility of SIF in extracting phenological metrics in permafrost regions of the northeastern China,exploring the characteristics of SIF in the study of vegetation phenology and the differences between NDVI and EVI.The results show that NDVI has obvious SOS advance and EOS lag,and EVI is closer to SIF.The growing season length based on SIF is often the shortest,while it can represent the true phenology of vegetation because it is closely related to photosynthesis.SIF is more sensitive than the traditional remote sensing indices in monitoring seasonal changes in vegetation phenology and can compensate for the shortcomings of traditional vegetation indices.We also used the time series data of MODIS NDVI and EVI to extract phenological metrics in different permafrost regions.The results show that the length of growing season of vegetation in predominantly continuous permafrost(zone I)is longer than in permafrost with isolated taliks(zone II).Our results have certain significance for understanding the response of ecosystems in cold regions to global climate change.
文摘中国人民形象的海外传播对中国大国形象构建具有重要的促进作用。基于态度系统理论框架,借助UAM Corpus Tool,对《习近平谈治国理政》及其英译本中的态度资源进行描述性统计分析和主题分析,发现原文与译文主要通过积极的判断资源评价和塑造中国人民形象,具体体现在创造力强、爱好和平、勤劳勇敢和自强不息4个方面。在整个译介过程中,译者以遵循准确性为首要原则,充分考虑汉英语言差异,灵活采用一词多译、句型调整、语义融合等多种翻译策略与方法来转换态度资源,以确保译文的接受效果,帮助国际受众更好地理解中国人民形象的具体内涵。文章通过翻译实例分析我国政治文本中中国人民形象英译现状,以期为外宣翻译实践和研究提供有益镜鉴。
