Predicting the responses of an alluvial channel to changes in flow and sediment supply is essential for engineering design. Many methods have been developed in the last few decades to describe sectional bankfull chara...Predicting the responses of an alluvial channel to changes in flow and sediment supply is essential for engineering design. Many methods have been developed in the last few decades to describe sectional bankfull characteristics(elevation and discharge); however, studies on long-term reach-scale bankfull discharge are still limited. In this study, a hydraulic model is built to calculate the reach-scale bankfull discharge, and the effects of reservoir building on downstream bankfull discharges are discussed. The studied river reach is located at the lower Wei River(WR), where the planned Dongzhuang Reservoir would be built on its largest tributary, the Jing River. A quasi-two-dimensional numerical model coupled with a bankfull discharge estimating method is put forward to calculate the reach-scale bankfull discharge. The soundness of the model is verified. Results show that the temporal variation of reach-scale bankfull discharge of the lower reach of the WR would be highly influenced by the planned reservoir, especially during the first 20 years of operation. The effect of the planned reservoir on bankfull discharge may reach its maximum when the total trapped sediment load reaches approximately 75% of the reservoir capacity. Our results show that after the first 17 years of operation,the effect of the planned reservoir on bankfull discharge of the river reach may decrease gradually.The soundness and predictive capability of the coupled model have also been calibrated by comparing with existing reservoirs. All analyses indicate that the numerical model can be used to predict the changed reach-scale bankfull discharge of the lower WR.展开更多
Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood...Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood are natural disasters bringing about the most serious damage, and drought risk in east central Weihe Plain is serious. In Fen-wei Plain, precipitation tended to decrease, and temperature, drought days and intensity increased over the past 50 years. There were obvious differences between two decades in drought and flood. Drought was the severest in the 1990s, and flood was the most serious in Fenhe Plain in the 1960s and in Weihe Plain from the late 1970s to the early 1980s. Over the past ten years, precipitation and flood frequency increased, and temperature, drought days and intensity decreased. In Fen-wei Plain, temperature will rise and precipitation will increase slightly in next 20 -40 years. Monitoring and early warning capability of drought and flood in Fen-wei Plain have im- proved gradually, but some issues need to be paid more attention to and solved.展开更多
Objective： To evaluate the efficacy and safety of Chinese medicine （CM） decoction Chang＇an I Recipe （肠安 Ⅰ号方） in the treatment of irritable bowel syndrome with diarrhea （IBS-D）. Method： A multicenter, ran...Objective： To evaluate the efficacy and safety of Chinese medicine （CM） decoction Chang＇an I Recipe （肠安 Ⅰ号方） in the treatment of irritable bowel syndrome with diarrhea （IBS-D）. Method： A multicenter, randomized, double-blind, placebo-controlled clinical trial was designed. Based on the order of inclusion, the IBS-D patients were randomly assigned to the treatment group or the placebo control group, administrated with Chang＇an I Recipe or placebo, 150 mL/bag, 3 times daily, for 8 weeks. The primary indices of efficacy included the effective rates of IBS symptom severity score （IBS-SSS） and the differences in adequate relief （AR） responder; the secondary indexes of efficacy included the changes in scores of the IBS Quality of Life （IBS-QOL） and Hospital Anxiety and Depression （HAD） scales. The safety indices included adverse events and related laboratory tests. Results： A total of 216 patients were included, with 109 in the treatment group and 107 in the control group, and finally 206 were included in the full analysis set （FAS）, 191 were included in the per protocol set （PPS）. In FAS, the total effective rate was 67.6% and 40.2% for the treatment and control groups, respectively, with 95% confidence interval （CI） for difference in the effective rates between the two groups of 14.4%-40.2%; while in PPS, the total effective rate was 71.3% and 41.2% for the treatment and control groups, respectively （95% CI 16.6%-43.4%）. The consistent conclusions of FAS and PPS showed a better efficacy in the treatment group. Both FAS and PPS showed higher AR responder in the treatment group （FAS： 59.6% vs. 35.5%; PPS： 62.8% vs. 38.1%）. As for IBS-QOL, the total score and scores in various dimensions of IBS-QOL were not significantly different between the two groups （P〉0.05）. Both anxiety and depression scales of HAD were not significantly different between the two groups （P〉0.05）. No adverse events or laboratory abnormalities were found to be obviously related to the tested drugs or clinically significant. Conclusion： Chang＇an I Recipe was more effective than placebo in the treatment of IBS-D, with no obvious adverse reactions. （No,ChiCTR-TRC-09000328）展开更多
基金funded by the National Natural Science Foundation of China(Grants No.2011CB403305,51579230,51109198,41571005,and 51479179)
文摘Predicting the responses of an alluvial channel to changes in flow and sediment supply is essential for engineering design. Many methods have been developed in the last few decades to describe sectional bankfull characteristics(elevation and discharge); however, studies on long-term reach-scale bankfull discharge are still limited. In this study, a hydraulic model is built to calculate the reach-scale bankfull discharge, and the effects of reservoir building on downstream bankfull discharges are discussed. The studied river reach is located at the lower Wei River(WR), where the planned Dongzhuang Reservoir would be built on its largest tributary, the Jing River. A quasi-two-dimensional numerical model coupled with a bankfull discharge estimating method is put forward to calculate the reach-scale bankfull discharge. The soundness of the model is verified. Results show that the temporal variation of reach-scale bankfull discharge of the lower reach of the WR would be highly influenced by the planned reservoir, especially during the first 20 years of operation. The effect of the planned reservoir on bankfull discharge may reach its maximum when the total trapped sediment load reaches approximately 75% of the reservoir capacity. Our results show that after the first 17 years of operation,the effect of the planned reservoir on bankfull discharge of the river reach may decrease gradually.The soundness and predictive capability of the coupled model have also been calibrated by comparing with existing reservoirs. All analyses indicate that the numerical model can be used to predict the changed reach-scale bankfull discharge of the lower WR.
基金Supported by the Major Consulting Project of the Chinese Academy of Engineering(2012-ZD-13)Science and Technology Research and Development Program of Shaanxi Province,China(2014k13-09)
文摘Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood are natural disasters bringing about the most serious damage, and drought risk in east central Weihe Plain is serious. In Fen-wei Plain, precipitation tended to decrease, and temperature, drought days and intensity increased over the past 50 years. There were obvious differences between two decades in drought and flood. Drought was the severest in the 1990s, and flood was the most serious in Fenhe Plain in the 1960s and in Weihe Plain from the late 1970s to the early 1980s. Over the past ten years, precipitation and flood frequency increased, and temperature, drought days and intensity decreased. In Fen-wei Plain, temperature will rise and precipitation will increase slightly in next 20 -40 years. Monitoring and early warning capability of drought and flood in Fen-wei Plain have im- proved gradually, but some issues need to be paid more attention to and solved.
基金Supported by China International Sciences and Technology Cooperation Program(No.2007DFA30560)
文摘Objective： To evaluate the efficacy and safety of Chinese medicine （CM） decoction Chang＇an I Recipe （肠安 Ⅰ号方） in the treatment of irritable bowel syndrome with diarrhea （IBS-D）. Method： A multicenter, randomized, double-blind, placebo-controlled clinical trial was designed. Based on the order of inclusion, the IBS-D patients were randomly assigned to the treatment group or the placebo control group, administrated with Chang＇an I Recipe or placebo, 150 mL/bag, 3 times daily, for 8 weeks. The primary indices of efficacy included the effective rates of IBS symptom severity score （IBS-SSS） and the differences in adequate relief （AR） responder; the secondary indexes of efficacy included the changes in scores of the IBS Quality of Life （IBS-QOL） and Hospital Anxiety and Depression （HAD） scales. The safety indices included adverse events and related laboratory tests. Results： A total of 216 patients were included, with 109 in the treatment group and 107 in the control group, and finally 206 were included in the full analysis set （FAS）, 191 were included in the per protocol set （PPS）. In FAS, the total effective rate was 67.6% and 40.2% for the treatment and control groups, respectively, with 95% confidence interval （CI） for difference in the effective rates between the two groups of 14.4%-40.2%; while in PPS, the total effective rate was 71.3% and 41.2% for the treatment and control groups, respectively （95% CI 16.6%-43.4%）. The consistent conclusions of FAS and PPS showed a better efficacy in the treatment group. Both FAS and PPS showed higher AR responder in the treatment group （FAS： 59.6% vs. 35.5%; PPS： 62.8% vs. 38.1%）. As for IBS-QOL, the total score and scores in various dimensions of IBS-QOL were not significantly different between the two groups （P〉0.05）. Both anxiety and depression scales of HAD were not significantly different between the two groups （P〉0.05）. No adverse events or laboratory abnormalities were found to be obviously related to the tested drugs or clinically significant. Conclusion： Chang＇an I Recipe was more effective than placebo in the treatment of IBS-D, with no obvious adverse reactions. （No,ChiCTR-TRC-09000328）
