Understanding streamflow changes in terms of trends and periodicities and relevant causes is the first step into scientific management of water resources in a changing environment. In this study, monthly streamflow va...Understanding streamflow changes in terms of trends and periodicities and relevant causes is the first step into scientific management of water resources in a changing environment. In this study, monthly streamflow variations were analyzed using Modified Mann-Kendall(MM-K) trend test and Continuous Wavelet Transform(CWT) methods at 9 hydrological stations in the Huaihe River Basin. It was found that: 1) streamflow mainly occurs during May to September, accounting for 70.4% of the annual total streamflowamount with Cv values between 0.16–0.85 and extremum ratio values between 1.70–23.90; 2) decreased streamflow can be observed in the Huaihe River Basin and significant decreased streamflow can be detected during April and May, which should be the results of precipitation change and increased irrigation demand; 3) significant periods of 2–4 yr were detected during the 1960 s, the 1980 s and the 2000 s. Different periods were found at stations concentrated within certain regions implying periods of streamflow were caused by different influencing factors for specific regions; 4) Pacific Decadal Oscillation(PDO) has the most significant impacts on monthly streamflow mainly during June. Besides, Southern Oscillation Index(SOI), North Atlantic Oscillation(NAO) and the Ni?o3.4 Sea Surface Temperature(Ni?o3.4) have impacts on monthly streamflow with three months lags, and was less significant in time lag of six months. Identification of critical climatic factors having impacts on streamflow changes can help to predict monthly streamflow changes using climatic factors as explanatory variables. These findings were well corroborated by results concerning impacts of El Nino-Southern Oscillation(ENSO) regimes on precipitation events across the Huaihe River Basin. The results of this study can provide theoretical background for basin-scale management of water resources and agricultural irrigation.展开更多
OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of ...OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of whole body, tachycardia, anxiety, dyspnea and severe nausea. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched up to April 2013 to find papers focused on phytochemistry and biological activities of this plant. RESULTS: Among chemical constituents present in Herba Portulacae oleraceae, catecholamines, adenosine and niacin can cause adverse events similar to those reported inTIM. CONCLUSION: Because of the short duration of action of adenosine, catecholamines and niacin seems to be the major role in appearance of ad-verse events reported in TIM for Herba Portulacae Oleraceae seed. Mechanisms with consideration of receptor types and pharmacokinetics of catecholamine and niacin are warranted to confirm this hypothesis.展开更多
基金Under the auspices of National Science Foundation of China(No.41601023,41771536)National Science Foundation for Distinguished Young Scholars of China(No.51425903)+2 种基金State Key Laboratory of Earth Surface Processes and Resource Ecology(No.2017-KF-04)Creative Research Groups of National Natural Science Foundation of China(No.41621061)Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin(China Institute of Water Resources and Hydropower Research)(No.IWHR-SKL-201720)
文摘Understanding streamflow changes in terms of trends and periodicities and relevant causes is the first step into scientific management of water resources in a changing environment. In this study, monthly streamflow variations were analyzed using Modified Mann-Kendall(MM-K) trend test and Continuous Wavelet Transform(CWT) methods at 9 hydrological stations in the Huaihe River Basin. It was found that: 1) streamflow mainly occurs during May to September, accounting for 70.4% of the annual total streamflowamount with Cv values between 0.16–0.85 and extremum ratio values between 1.70–23.90; 2) decreased streamflow can be observed in the Huaihe River Basin and significant decreased streamflow can be detected during April and May, which should be the results of precipitation change and increased irrigation demand; 3) significant periods of 2–4 yr were detected during the 1960 s, the 1980 s and the 2000 s. Different periods were found at stations concentrated within certain regions implying periods of streamflow were caused by different influencing factors for specific regions; 4) Pacific Decadal Oscillation(PDO) has the most significant impacts on monthly streamflow mainly during June. Besides, Southern Oscillation Index(SOI), North Atlantic Oscillation(NAO) and the Ni?o3.4 Sea Surface Temperature(Ni?o3.4) have impacts on monthly streamflow with three months lags, and was less significant in time lag of six months. Identification of critical climatic factors having impacts on streamflow changes can help to predict monthly streamflow changes using climatic factors as explanatory variables. These findings were well corroborated by results concerning impacts of El Nino-Southern Oscillation(ENSO) regimes on precipitation events across the Huaihe River Basin. The results of this study can provide theoretical background for basin-scale management of water resources and agricultural irrigation.
文摘OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of whole body, tachycardia, anxiety, dyspnea and severe nausea. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched up to April 2013 to find papers focused on phytochemistry and biological activities of this plant. RESULTS: Among chemical constituents present in Herba Portulacae oleraceae, catecholamines, adenosine and niacin can cause adverse events similar to those reported inTIM. CONCLUSION: Because of the short duration of action of adenosine, catecholamines and niacin seems to be the major role in appearance of ad-verse events reported in TIM for Herba Portulacae Oleraceae seed. Mechanisms with consideration of receptor types and pharmacokinetics of catecholamine and niacin are warranted to confirm this hypothesis.
