In the context of climate variability resulting in a decrease in rainfall with a severe drought, a spatio-temporal study of this phenomenon remains imperative for the efficient management of water resources. This pape...In the context of climate variability resulting in a decrease in rainfall with a severe drought, a spatio-temporal study of this phenomenon remains imperative for the efficient management of water resources. This paper aims to assess the long-term rainfall drought trend and breakpoints within the Comoe River watershed. From monthly rainfall data series (1960-2000), Standardized Precipitation Index (SPI) values were calculated for a time scale of 3 months (SPI.3). Statistical tests for breaks (CUSUM, and t-Student) and trends (Man-Kendall and Linear Regression) as well as the Sen’ slope method for estimating the magnitude of trends w<span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> applied. The breaks dates observed are mostly located after the 1970s. Based on SPI.3 values below the threshold of 0.84 chosen as an indicator of drought, rarely has more than half of the catchment area been affected by drought. The average watershed affected is about 20% over the study period (1960-2000). The most representative years, in terms of spatial expansion of the drought, in decreasing order of importance are: 1983, 1992, 1972 and 1982. The years 1982 and 1983 stand out for their exceptional condition, as the drought-affected 50% to 90% of the total catchment area. SPI.3 series from 1960 to the various break dates recorded slopes between </span><span style="font-family:Verdana;"><span style="white-space:nowrap;">-</span>0.01 and 0.00 with a slight drought trend for most of the catchment. After the break periods, almost the entire northern part of the basin is characterized by slight moisture with Sen’s slopes between 0.000 and 0.005. The southern part will remain slightly subject to normal rainfall conditions.</span>展开更多
采用紫外吸收光谱、荧光光谱及红外光谱研究了pH3.0、pH7.0、pH9.0条件下表没食子儿茶素没食子酸酯((-)-Epigallocatechin-3-gallate,EGCG)与大豆分离蛋白(Soy protein isolate,SPI)的相互作用。结果表明,EGCG与SPI之间能发生相互作用,...采用紫外吸收光谱、荧光光谱及红外光谱研究了pH3.0、pH7.0、pH9.0条件下表没食子儿茶素没食子酸酯((-)-Epigallocatechin-3-gallate,EGCG)与大豆分离蛋白(Soy protein isolate,SPI)的相互作用。结果表明,EGCG与SPI之间能发生相互作用,且在不同pH值下EGCG与SPI的相互作用可能会导致氨基酸残基微环境发生改变。EGCG对SPI的荧光具有强烈的静态猝灭作用;且SPI与EGCG的亲和力在pH7.0时最强。在pH3.0和pH7.0条件下,EGCG与SPI的结合主要是由范德华力和氢键驱动的自发络合过程;而在pH9.0条件下,EGCG与SPI之间的结合力主要为疏水作用。傅里叶变换红外光谱进一步表明EGCG与SPI之间的相互作用依靠多种作用力相互维持。在pH3.0、7.0条件下,除氢键外,两者的相互作用也包括了由疏水作用驱动的有利结合过程;此外,在pH9.0时,在EGCG与SPI的结合中观察到了共价作用。EGCG在不同pH值水平下诱导C—H弯曲振动等基团微环境的变化,这可能暗示着SPI与EGCG的结合可能使得SPI二级结构发生改变。展开更多
文摘In the context of climate variability resulting in a decrease in rainfall with a severe drought, a spatio-temporal study of this phenomenon remains imperative for the efficient management of water resources. This paper aims to assess the long-term rainfall drought trend and breakpoints within the Comoe River watershed. From monthly rainfall data series (1960-2000), Standardized Precipitation Index (SPI) values were calculated for a time scale of 3 months (SPI.3). Statistical tests for breaks (CUSUM, and t-Student) and trends (Man-Kendall and Linear Regression) as well as the Sen’ slope method for estimating the magnitude of trends w<span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> applied. The breaks dates observed are mostly located after the 1970s. Based on SPI.3 values below the threshold of 0.84 chosen as an indicator of drought, rarely has more than half of the catchment area been affected by drought. The average watershed affected is about 20% over the study period (1960-2000). The most representative years, in terms of spatial expansion of the drought, in decreasing order of importance are: 1983, 1992, 1972 and 1982. The years 1982 and 1983 stand out for their exceptional condition, as the drought-affected 50% to 90% of the total catchment area. SPI.3 series from 1960 to the various break dates recorded slopes between </span><span style="font-family:Verdana;"><span style="white-space:nowrap;">-</span>0.01 and 0.00 with a slight drought trend for most of the catchment. After the break periods, almost the entire northern part of the basin is characterized by slight moisture with Sen’s slopes between 0.000 and 0.005. The southern part will remain slightly subject to normal rainfall conditions.</span>
文摘采用紫外吸收光谱、荧光光谱及红外光谱研究了pH3.0、pH7.0、pH9.0条件下表没食子儿茶素没食子酸酯((-)-Epigallocatechin-3-gallate,EGCG)与大豆分离蛋白(Soy protein isolate,SPI)的相互作用。结果表明,EGCG与SPI之间能发生相互作用,且在不同pH值下EGCG与SPI的相互作用可能会导致氨基酸残基微环境发生改变。EGCG对SPI的荧光具有强烈的静态猝灭作用;且SPI与EGCG的亲和力在pH7.0时最强。在pH3.0和pH7.0条件下,EGCG与SPI的结合主要是由范德华力和氢键驱动的自发络合过程;而在pH9.0条件下,EGCG与SPI之间的结合力主要为疏水作用。傅里叶变换红外光谱进一步表明EGCG与SPI之间的相互作用依靠多种作用力相互维持。在pH3.0、7.0条件下,除氢键外,两者的相互作用也包括了由疏水作用驱动的有利结合过程;此外,在pH9.0时,在EGCG与SPI的结合中观察到了共价作用。EGCG在不同pH值水平下诱导C—H弯曲振动等基团微环境的变化,这可能暗示着SPI与EGCG的结合可能使得SPI二级结构发生改变。
