为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被...为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被NPP变化的影响。研究表明:(1)研究区内植被NPP整体呈现缓慢增长的趋势,增长率为7.53 g C·m^(-2)·a^(-1),同时植被NPP均值分布呈现四周高中间低的空间格局。(2)研究区内气候因子对植被NPP变化的影响存在空间异质性,在眉山市、乐山市、雅安市以及重庆市黔江区、彭水县部分地区气温与植被NPP负相关关系明显,其呈正相关关系的区域广泛分布在成渝城市群的中部和东部;降水与植被NPP呈正相关关系的区域面积占比达到92.46%。(3)研究区主要受非气候因子影响,面积占比高达86.87%,说明人类活动对植被NPP变化的影响愈来愈烈,研究人为影响应是成渝城市群生态修复的重点。展开更多
The transfer of pressurized water reactor(PWR)technology from France to China is an important event in the history of Sino-French scientific and technological relations.China has gradually achieved self-reliance in th...The transfer of pressurized water reactor(PWR)technology from France to China is an important event in the history of Sino-French scientific and technological relations.China has gradually achieved self-reliance in the field of PWR technology through the introduction and subsequent absorption of France's 900 MW reactors.Compared with the process of introducing and absorbing similar technology from the United States by France,China's experience has been more complicated.This circumstance reflects the differences in the nuclear power technology systems between the two countries.France's industrial strength and early acquisition of nuclear power technology laid a solid foundation for mastering PWR technology.On the other hand,although China established a weak foundation through the implementation of the"728 Project,"and tried hard to negotiate with France,the substantive content of the technology transfer was very limited.By way of the policy transition from"unhooking of technology and trade"to"integration of technology and trade,"China ultimately accomplished the absorption and innovation of PWR technology through the Ling'ao NPP.展开更多
Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into...Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into photosynthesis. It is very sensible for factors affecting on vegetation variability such as climate, soils, plant characteristics and human activities. So, it can be used as an indicator of actual and potential trend of vegetation. In this study we used the actual NPP which was derived from MODIS to assess the response of NPP to climate variables in Gadarif State, from 2000 to 2010. The correlations between NPP and climate variables (temperature and precipitation) are calculated using Pearson’s Correlation Coefficient and ordinary least squares regression. The main results show the following 1) the correlation Coefficient between NPP and mean annual temperature is Somewhat negative for Feshaga, Rahd, Gadarif and Galabat areas and weakly negative in Faw area;2) the correlation Coefficient between NPP and annual total precipitation is weakly negative in Faw, Rahd and Galabat areas and somewhat negative in Galabat and Rahd areas. This study demonstrated that the correlation analysis between NPP and climate variables (precipitation and temperature) gives reliably result of NPP responses to climate variables that is clearly in a very large scale of study area.展开更多
文摘为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被NPP变化的影响。研究表明:(1)研究区内植被NPP整体呈现缓慢增长的趋势,增长率为7.53 g C·m^(-2)·a^(-1),同时植被NPP均值分布呈现四周高中间低的空间格局。(2)研究区内气候因子对植被NPP变化的影响存在空间异质性,在眉山市、乐山市、雅安市以及重庆市黔江区、彭水县部分地区气温与植被NPP负相关关系明显,其呈正相关关系的区域广泛分布在成渝城市群的中部和东部;降水与植被NPP呈正相关关系的区域面积占比达到92.46%。(3)研究区主要受非气候因子影响,面积占比高达86.87%,说明人类活动对植被NPP变化的影响愈来愈烈,研究人为影响应是成渝城市群生态修复的重点。
基金a phase study of a key project of the Fourteenth Five-Year Plan of the Institute for the History of Natural Sciences,Chinese Academy of Sciences:“A Comparative Study of the Sino-Foreign History of Scientific and Technological Innovation:The Road to Scientific and Technological Self-Reliance and Self-Improvement”,E2291J01。
文摘The transfer of pressurized water reactor(PWR)technology from France to China is an important event in the history of Sino-French scientific and technological relations.China has gradually achieved self-reliance in the field of PWR technology through the introduction and subsequent absorption of France's 900 MW reactors.Compared with the process of introducing and absorbing similar technology from the United States by France,China's experience has been more complicated.This circumstance reflects the differences in the nuclear power technology systems between the two countries.France's industrial strength and early acquisition of nuclear power technology laid a solid foundation for mastering PWR technology.On the other hand,although China established a weak foundation through the implementation of the"728 Project,"and tried hard to negotiate with France,the substantive content of the technology transfer was very limited.By way of the policy transition from"unhooking of technology and trade"to"integration of technology and trade,"China ultimately accomplished the absorption and innovation of PWR technology through the Ling'ao NPP.
文摘Plants play an essential role in matter and energy transformations and are key messengers in the carbon and energy cycle. Net primary productivity (NPP) reflects the capability of plants to transform solar energy into photosynthesis. It is very sensible for factors affecting on vegetation variability such as climate, soils, plant characteristics and human activities. So, it can be used as an indicator of actual and potential trend of vegetation. In this study we used the actual NPP which was derived from MODIS to assess the response of NPP to climate variables in Gadarif State, from 2000 to 2010. The correlations between NPP and climate variables (temperature and precipitation) are calculated using Pearson’s Correlation Coefficient and ordinary least squares regression. The main results show the following 1) the correlation Coefficient between NPP and mean annual temperature is Somewhat negative for Feshaga, Rahd, Gadarif and Galabat areas and weakly negative in Faw area;2) the correlation Coefficient between NPP and annual total precipitation is weakly negative in Faw, Rahd and Galabat areas and somewhat negative in Galabat and Rahd areas. This study demonstrated that the correlation analysis between NPP and climate variables (precipitation and temperature) gives reliably result of NPP responses to climate variables that is clearly in a very large scale of study area.
