To control soil erosion and restore the degraded environment in the Loess Plateau, a large number of measures related to soil and water conservation have been employed that have profoundly affected catchment propertie...To control soil erosion and restore the degraded environment in the Loess Plateau, a large number of measures related to soil and water conservation have been employed that have profoundly affected catchment properties. This study constructed three indicators to characterize changes to the catchment slope, proposed both a method for a regression analysis of adjacent images and a sequence model, and applied multisource remotely sensed images and GIS spatial clustering analysis technologies to extract thematic information and comprehensively analyze the catchment change characteristics. The results indicate that the catchment slope properties changed significantly. At catchment scale, the average values of ARC, DVC and ART were 6.43%, 25.57% and 4.30%, respectively. There were six clustering types of catchment slope property changes. The maximum and minimum of the average similarities of the clustering types were 0.992 and 0.935. Each slope control measures had a distinct effect on catchment slope; the dominating factor of each clustering type was identified as： Type 1： D-VC, Type 2： D-VCLU, Type 3： D-LUVC, Type 4： D-TAVC, Type 5： D-TAC and Type 6： D-MFC. Type 5 and Type 1 covered the largest areas, respectively occupying 37.28% and 31.01%. Catchment slope property changes also had distinct types that depended on their geomorphological conditions. These findings provide a useful basis from which to further study catchment slope hydrological and soil erosion processes.展开更多
Tricuspid valve regurgitation is a rare complication of blunt chest trauma.Approximately 150 cases have been reported since first being described by Todd et al in 1848.1 During the past few decades traumatic tricuspid...Tricuspid valve regurgitation is a rare complication of blunt chest trauma.Approximately 150 cases have been reported since first being described by Todd et al in 1848.1 During the past few decades traumatic tricuspid regurgitation has been reported with increasing frequency,which may in part be attributed to more patients surviving blunt chest trauma as well as improved diagnostic imaging studies,such as echocardiography.The incidence of traumatic tricuspid regurgitation is likely underestimated since chronic,isolated tricuspid insufficiency may be well tolerated in some patients who experience few or no symptoms after the traumatic event.2 Furthermore,some patients may not recall antecedent chest trauma unless specifically questioned.Most cases of traumatic tricuspid regurgitation are secondary to blunt chest trauma.1展开更多
基金National Key Technologies R&D Program,No.2012BAB02B00Public Welfare Foundation of the Ministry of Water Resources,No.201101037The Fundamental Research Funds for the Central Universities
文摘To control soil erosion and restore the degraded environment in the Loess Plateau, a large number of measures related to soil and water conservation have been employed that have profoundly affected catchment properties. This study constructed three indicators to characterize changes to the catchment slope, proposed both a method for a regression analysis of adjacent images and a sequence model, and applied multisource remotely sensed images and GIS spatial clustering analysis technologies to extract thematic information and comprehensively analyze the catchment change characteristics. The results indicate that the catchment slope properties changed significantly. At catchment scale, the average values of ARC, DVC and ART were 6.43%, 25.57% and 4.30%, respectively. There were six clustering types of catchment slope property changes. The maximum and minimum of the average similarities of the clustering types were 0.992 and 0.935. Each slope control measures had a distinct effect on catchment slope; the dominating factor of each clustering type was identified as： Type 1： D-VC, Type 2： D-VCLU, Type 3： D-LUVC, Type 4： D-TAVC, Type 5： D-TAC and Type 6： D-MFC. Type 5 and Type 1 covered the largest areas, respectively occupying 37.28% and 31.01%. Catchment slope property changes also had distinct types that depended on their geomorphological conditions. These findings provide a useful basis from which to further study catchment slope hydrological and soil erosion processes.
文摘Tricuspid valve regurgitation is a rare complication of blunt chest trauma.Approximately 150 cases have been reported since first being described by Todd et al in 1848.1 During the past few decades traumatic tricuspid regurgitation has been reported with increasing frequency,which may in part be attributed to more patients surviving blunt chest trauma as well as improved diagnostic imaging studies,such as echocardiography.The incidence of traumatic tricuspid regurgitation is likely underestimated since chronic,isolated tricuspid insufficiency may be well tolerated in some patients who experience few or no symptoms after the traumatic event.2 Furthermore,some patients may not recall antecedent chest trauma unless specifically questioned.Most cases of traumatic tricuspid regurgitation are secondary to blunt chest trauma.1
