Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this m...Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this model with SPOT/NDVI data,three key vegetation phenology metrics,the start of growing season (SOS),the end of growing season (EOS) and the length of growing season (LOS),were extracted and mapped in the Changbai Mountains,and the relationship between the key phenology metrics and elevation were established.Results show that average SOS of forest,cropland and grassland in the Changbai Mountains are on the 119th,145th,and 133rd day of year,respectively.The EOS of forest and grassland are similar,with the average on the 280th and 278th,respectively.In comparison,average EOS of the cropland is relatively earlier.The LOS of forest is mainly from the 160th to 180th,that of the grassland extends from the 140th to the 160th,and that of cropland stretches from the 110th to the 130th.As the latitude increases for the same land cover in the study area,the SOS significantly delays and the EOS becomes earlier.The SOS delays approximately three days as the elevation increases 100 m in the areas with elevation higher than 900 m above sea level (a.s.l.).The EOS is slightly earlier as the elevation increases especially in the areas with elevation below 1200 m a.s.l.The LOS shortens approximately four days as the elevation increases 100 m in the areas with elevation higher than 900 m a.s.l.The relationships between vegetation phenology metrics and elevation may be greatly influenced by the land covers.Validation by comparing with the field data and previous research results indicates that the improved logistic model is reliable and effective for extracting vegetation phenology metrics.展开更多
The rate of regional sea level rise （SLR） provides important information about the impact of human activities on climate change. However, accurate estimation of regional SLR can be severely affected by sea surface h...The rate of regional sea level rise （SLR） provides important information about the impact of human activities on climate change. However, accurate estimation of regional SLR can be severely affected by sea surface height （SSH） change caused by the Pacific Decadal Oscillation （PDO-SSH）. Here, the PDO- SSH signal is extracted from satellite altimeter data by multi-variable linear regression, and regional SLR in the altimeter era is calculated, before and after removing that signal. The results show that PDO-SSH trends are rising in the western Pacific and falling in the eastern Pacific, with the strongest signal confined to the tropical and North Pacific. Over the past 20 years, the PDO-SSH accounts for about 30%/-400% of altimeter-observed SLR in the regions 8° 15°N, 130°-160°E and 30°-40°N, 170°-220°E. Along the coast ＆North America, the PDO-SSH signal dramatically offsets the coastal SLR, as the sea level trends change sign from falling to rising.展开更多
The aim of this study was to optimize the conditions for the extraction of low-abundance proteins（LAPs） and the removal of abundant proteins（APs; β-conglycinin and glycinin） from soybean meal.Single factor and or...The aim of this study was to optimize the conditions for the extraction of low-abundance proteins（LAPs） and the removal of abundant proteins（APs; β-conglycinin and glycinin） from soybean meal.Single factor and orthogonal experiments were designed to determine the effects of four factors（isopropanol concentration, total extraction time, ultrasonic power, and ultrasonic time） on protein concentration in isopropanol extracts.Proteins in the isopropanol supernatant and the cold acetone precipitate of isopropanol were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE） and matrix-assisted laser desorption/ionization-time of flight mass spectrometry（MALDI-TOF-MS）.The results showed that the optimal conditions were 50% isopropanol, ultrasonic pretreatment for 15 min at 350 W, and a total extraction time of 1 h.Under these conditions, the protein concentration in the isopropanol extracts reached 0.8081 g/L.Many LAPs were detected, including β-amylase, soybean agglutinin, soybean trypsin inhibitor, fumarylacetoacetase-like, phospholipase D alpha 1-like, oleosin, and even some unknown soybean proteins.The soybean APs（β-conglycinin and glycinin） were not found.The method may be useful for discovering new soybean proteins and extracting enough LAPs of soybean to allow further studies of their physiological effects on animals without the influence of APs.展开更多
基金Under the auspices of Major State Basic Research Development Program of China (No.2009CB426305)Cultivation Foundation of Science and Technology Innovation Platform of Northeast Normal University (No.106111065202)
文摘Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this model with SPOT/NDVI data,three key vegetation phenology metrics,the start of growing season (SOS),the end of growing season (EOS) and the length of growing season (LOS),were extracted and mapped in the Changbai Mountains,and the relationship between the key phenology metrics and elevation were established.Results show that average SOS of forest,cropland and grassland in the Changbai Mountains are on the 119th,145th,and 133rd day of year,respectively.The EOS of forest and grassland are similar,with the average on the 280th and 278th,respectively.In comparison,average EOS of the cropland is relatively earlier.The LOS of forest is mainly from the 160th to 180th,that of the grassland extends from the 140th to the 160th,and that of cropland stretches from the 110th to the 130th.As the latitude increases for the same land cover in the study area,the SOS significantly delays and the EOS becomes earlier.The SOS delays approximately three days as the elevation increases 100 m in the areas with elevation higher than 900 m above sea level (a.s.l.).The EOS is slightly earlier as the elevation increases especially in the areas with elevation below 1200 m a.s.l.The LOS shortens approximately four days as the elevation increases 100 m in the areas with elevation higher than 900 m a.s.l.The relationships between vegetation phenology metrics and elevation may be greatly influenced by the land covers.Validation by comparing with the field data and previous research results indicates that the improved logistic model is reliable and effective for extracting vegetation phenology metrics.
基金Supported by the National Natural Science Foundation of China(No.41376028)the Knowledge Innovation Program of Chinese Academy of Sciences(CAS)(No.Y22114101Q)+2 种基金the National Basic Research Program of China(973 Program)(No.2013CB956202)the"100-Talent Project"of Chinese Academy of Sciences,China(No.Y32109101L)the Special Funds of CAS(No.XDAl 1040205)
文摘The rate of regional sea level rise （SLR） provides important information about the impact of human activities on climate change. However, accurate estimation of regional SLR can be severely affected by sea surface height （SSH） change caused by the Pacific Decadal Oscillation （PDO-SSH）. Here, the PDO- SSH signal is extracted from satellite altimeter data by multi-variable linear regression, and regional SLR in the altimeter era is calculated, before and after removing that signal. The results show that PDO-SSH trends are rising in the western Pacific and falling in the eastern Pacific, with the strongest signal confined to the tropical and North Pacific. Over the past 20 years, the PDO-SSH accounts for about 30%/-400% of altimeter-observed SLR in the regions 8° 15°N, 130°-160°E and 30°-40°N, 170°-220°E. Along the coast ＆North America, the PDO-SSH signal dramatically offsets the coastal SLR, as the sea level trends change sign from falling to rising.
基金Project supported by the China Agriculture Research System(No.CARS-36)the National Natural Science Foundation of China(No.31572430)
文摘The aim of this study was to optimize the conditions for the extraction of low-abundance proteins（LAPs） and the removal of abundant proteins（APs; β-conglycinin and glycinin） from soybean meal.Single factor and orthogonal experiments were designed to determine the effects of four factors（isopropanol concentration, total extraction time, ultrasonic power, and ultrasonic time） on protein concentration in isopropanol extracts.Proteins in the isopropanol supernatant and the cold acetone precipitate of isopropanol were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE） and matrix-assisted laser desorption/ionization-time of flight mass spectrometry（MALDI-TOF-MS）.The results showed that the optimal conditions were 50% isopropanol, ultrasonic pretreatment for 15 min at 350 W, and a total extraction time of 1 h.Under these conditions, the protein concentration in the isopropanol extracts reached 0.8081 g/L.Many LAPs were detected, including β-amylase, soybean agglutinin, soybean trypsin inhibitor, fumarylacetoacetase-like, phospholipase D alpha 1-like, oleosin, and even some unknown soybean proteins.The soybean APs（β-conglycinin and glycinin） were not found.The method may be useful for discovering new soybean proteins and extracting enough LAPs of soybean to allow further studies of their physiological effects on animals without the influence of APs.
