This study investigated numerically the characteristics of laminar flow around two identical circular cylinders placed in tandem, with slits of the same width through their respective axis. The center to center distan...This study investigated numerically the characteristics of laminar flow around two identical circular cylinders placed in tandem, with slits of the same width through their respective axis. The center to center distance between the cylinders and the slit orientation were varied to study their effects on the flow structure, lift and drag, and vortex shedding characteristics. It was found that three flow regimes could be distinguished, the transitions between which could be indicated by the sudden changes in drag and lift. Asymmetrically, configured slits destabilized the stagnant region between cylinders;whereas in-line slits connect the two cylinders to act as a single elongated bluff body, even at large cylinder separation, by stabilizing the stagnant region in between. These in turn strongly modified the transition between flow regimes. Vortex shedding was also strongly influenced by both slit configuration and cylinder separation.展开更多
A series of safety incidents related to domestically-produced infant formulas(DIFs) almost destroyed Chinese consumer confidence in domestic dairy products. Understanding consumer confidence and its effect on consumpt...A series of safety incidents related to domestically-produced infant formulas(DIFs) almost destroyed Chinese consumer confidence in domestic dairy products. Understanding consumer confidence and its effect on consumption behavior is important to restore consumer confidence and enhance the competitiveness of domestic dairy industry. This article first measures Chinese consumer confidence in DIFs safety using a two-dimension scale(optimism and pessimism) and then investigates its effect on consumers’ preferences for DIFs through a choice experiment. Involving 450 consumers residing in Beijing, Tianjin and Shijiazhuang, the experiment elicited information on their preferences for DIFs with six attributes(organic raw milk, farm-to-table traceability, region of origin, quality certification, animal welfare, and price). Our analysis yields four findings. First, Chinese consumers still lack confidence in DIFs safety. Second, quality certification is the most preferred product characteristic, followed by organic raw milk and farm-to-table traceability. Third, serving as a signal of high quality, price exerts a positive impact on choices of DIFs for pessimistic consumers. Finally, consumer preferences for farm-to-table traceability and region of origin are significantly influenced by consumer confidence.展开更多
基金Project(51576213) supported by the National Natural Science Foundation of ChinaProject(2017JJ1031) supported by Hunan Provincial Natural Science Foundation of China+1 种基金Project(CSUZC201921) supported by the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,ChinaProject(2019zzts536) supported by the Fundamental Research Funds for the Central Universities,China
文摘This study investigated numerically the characteristics of laminar flow around two identical circular cylinders placed in tandem, with slits of the same width through their respective axis. The center to center distance between the cylinders and the slit orientation were varied to study their effects on the flow structure, lift and drag, and vortex shedding characteristics. It was found that three flow regimes could be distinguished, the transitions between which could be indicated by the sudden changes in drag and lift. Asymmetrically, configured slits destabilized the stagnant region between cylinders;whereas in-line slits connect the two cylinders to act as a single elongated bluff body, even at large cylinder separation, by stabilizing the stagnant region in between. These in turn strongly modified the transition between flow regimes. Vortex shedding was also strongly influenced by both slit configuration and cylinder separation.
基金funded by a grant from the Ministry of Agriculture and Rural Affairs of China (05162130111242003)Sino-Dutch Dairy Development Centre (SDDDC2017R02)
文摘A series of safety incidents related to domestically-produced infant formulas(DIFs) almost destroyed Chinese consumer confidence in domestic dairy products. Understanding consumer confidence and its effect on consumption behavior is important to restore consumer confidence and enhance the competitiveness of domestic dairy industry. This article first measures Chinese consumer confidence in DIFs safety using a two-dimension scale(optimism and pessimism) and then investigates its effect on consumers’ preferences for DIFs through a choice experiment. Involving 450 consumers residing in Beijing, Tianjin and Shijiazhuang, the experiment elicited information on their preferences for DIFs with six attributes(organic raw milk, farm-to-table traceability, region of origin, quality certification, animal welfare, and price). Our analysis yields four findings. First, Chinese consumers still lack confidence in DIFs safety. Second, quality certification is the most preferred product characteristic, followed by organic raw milk and farm-to-table traceability. Third, serving as a signal of high quality, price exerts a positive impact on choices of DIFs for pessimistic consumers. Finally, consumer preferences for farm-to-table traceability and region of origin are significantly influenced by consumer confidence.
