Background:The basic objective of this study was to examine the relationship between the rice output,its production area,water availability,and agricultural gross domestic product(GDP)of Pakistan.Annual time series da...Background:The basic objective of this study was to examine the relationship between the rice output,its production area,water availability,and agricultural gross domestic product(GDP)of Pakistan.Annual time series data for 1970–2015 were collected from the National Food Security and Research,Economic Survey of Pakistan,and Pakistan Bureau of Statistics(various publications).Methods:Rice crop data were analyzed using the ordinary least square method and the augmented Dickey–Fuller test.Were interpreted using the Johansen cointegration test.Results:Our study revealed the existence of a long-standing relationship between rice output,its production area,and water availability with the agricultural GDP of Pakistan.Regression results indicate that rice output and cultivated area have a significant and positive relationship with agricultural GDP,while water availability has a negative relationship.Conclusions:The study suggests that the government of Pakistan should design new policies and funding schemes for developing and improving water availability.展开更多
Dihydropyran(DHP)compounds are not only found in natural products and bioactive molecules,but also serve as important precursors in organic synthesis.Nonetheless,traditional methods for the construction of such compou...Dihydropyran(DHP)compounds are not only found in natural products and bioactive molecules,but also serve as important precursors in organic synthesis.Nonetheless,traditional methods for the construction of such compounds are usually limited to disubstituted DHPs.To address this synthetic challenge,reported here is an efficient electrochemical strategy toward the selenated and trifluoromethylated DHP compounds.The reaction proceeded smoothly under mild electrolysis conditions.The broad substrate scope(>50 examples)and scalable synthesis demonstrated the complexity-building potential of the strategy.Initial mechanistic studies reveal that cyclization may involve a radical process.This protocol may promote the further development of diversified synthesis of multi-substituted dihydropyran.展开更多
文摘Background:The basic objective of this study was to examine the relationship between the rice output,its production area,water availability,and agricultural gross domestic product(GDP)of Pakistan.Annual time series data for 1970–2015 were collected from the National Food Security and Research,Economic Survey of Pakistan,and Pakistan Bureau of Statistics(various publications).Methods:Rice crop data were analyzed using the ordinary least square method and the augmented Dickey–Fuller test.Were interpreted using the Johansen cointegration test.Results:Our study revealed the existence of a long-standing relationship between rice output,its production area,and water availability with the agricultural GDP of Pakistan.Regression results indicate that rice output and cultivated area have a significant and positive relationship with agricultural GDP,while water availability has a negative relationship.Conclusions:The study suggests that the government of Pakistan should design new policies and funding schemes for developing and improving water availability.
基金supported by the National Key R&D Program of China(2022YFA1505100,2021YFA1500100)the National Natural Science Foundation of China(22031008)+1 种基金the Fundamental Research Funds for the Central Universities(2042022rc0030,2042023kf0108,2042023kf1002)the Science Foundation of Wuhan(2020010601012192)。
文摘Dihydropyran(DHP)compounds are not only found in natural products and bioactive molecules,but also serve as important precursors in organic synthesis.Nonetheless,traditional methods for the construction of such compounds are usually limited to disubstituted DHPs.To address this synthetic challenge,reported here is an efficient electrochemical strategy toward the selenated and trifluoromethylated DHP compounds.The reaction proceeded smoothly under mild electrolysis conditions.The broad substrate scope(>50 examples)and scalable synthesis demonstrated the complexity-building potential of the strategy.Initial mechanistic studies reveal that cyclization may involve a radical process.This protocol may promote the further development of diversified synthesis of multi-substituted dihydropyran.
