In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landfor...In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landform development and evolution of its drainage system to some extent. In this study, the geomorphic meaning, basic characteristics, morphological structure and the basic types of loess gully heads were systematically analysed. Then, the loess gully head′s conceptual model was established, and an extraction method based on Digital Elevation Model(DEM) for loess gully head features and elements was proposed. Through analysing the achieved statistics of loess gully head features, loess gully heads have apparently similar and different characteristics depending on the different loess landforms where they are found. The loess head characteristics reflect their growth period and evolution tendency to a certain degree, and they indirectly represent evolutionary mechanisms. In addition, the loess gully developmental stages and the evolutionary processes can be deduced by using loess gully head characteristics. This study is of great significance for development and improvement of the theoretical system for describing loess gully landforms.展开更多
Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention. This paper explored the symmetry betw...Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention. This paper explored the symmetry between physical and human systems through fractal analysis of the road and drainage networks in Wuling mountainous area. We found that both the road and drainage networks reflect weak clustering distributions. The evolution of the road network shared a significant self-organizing composition, while the drainage network showed obvious double fraetal characteristics. The geometric fractal dimension of the road network was larger than that of the drainage network. In addition, when assigned a weight relating to hierarchy or length, neither the road network nor drainage network showed a fractal property. These findings indicated that the fractal evolution of the road network shared certain similarities with fractal distribution of the drainage network. The symmetry between the two systems resulted from an interactive process of destroying symmetry at the lower order and reconstructing symmetry at the higher order. The relationships between the fractal dimensions of the rural-urban road network, the drainage network andthe urban system indicated that the development of this area was to achieve the symmetrical isomorphism of physical-human geographical systems.展开更多
The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe (sewage and branch pipes respectively) which can be into other houses without going through floors! This techno...The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe (sewage and branch pipes respectively) which can be into other houses without going through floors! This technology has many advantages, like easy to construct and install at the same floor on one hand; on the other hand, when sewage or waste reach the top compared with the same kind drainage systems and other drainage methods, it can smoothly enter the main pipe (the chief vertical one). Moreover, once there is any situation needing dredge and cleaning, this problem can be solved at the same floor without interrupting the lives of other families. Last but not the least, it is so convenient to create a clean and tidy washing room. The branch pipe without being through floors is the very reason to solve the problem of surface condensation relative to sewage pipe in the rainy days, which correspondingly increases the hcight of head room indoor, is more favorable for fire prevention and much easier to keep smooth pipe flow.展开更多
The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance ...The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance between water, soil and man, which is now changed by modem irrigation and drainage systems. The oases pump most of their water from deep aquifers and only to a small degree from shallow aquifers. The quality of the irrigation water and the presence of a shallow saline water table are the main causes of salinization of the oases. Concerning the salt-affected landscapes and hydro-saline dynamic, the authors distinguish an equilibrium dynamic of salts to the parcel which depends on water management, and an equilibrium dynamic at the level of the basin watershed which is powered by drilling and ending in hypersaline depressions. For the management of salinization and waterlogging, a combination of agricultural management techniques are used, the first being modem methods of irrigation and drainage. Other, less used methods are sandy amendment, the reuse of drainage waters, geothermal waters and of treated wastewater.展开更多
To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of qua...To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of quantitative regulations of urban underlying surface rainfall infiltration conditions and a practical application of a simulated experimental system.In a com- prehensive analysis of the composition of an effective rainwater harvesting system and selection of water storage material,we simulated the major parameters of an experimental area rainfall,soil moisture and water storage capacity by providing an effective regulation of the experimental area runoff coefficient,obtained from basic data.展开更多
Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. M...Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. Methods: Thirty patients with isolated Judet III and IV fractures were included in this prospective study. Judet I and II fractures and radial neck fractures associated with other injuries were excluded. The final results were graded using the Metaizeau functional scoring system and Oxford Elbow Score. Results: The functional result was good to excellent in 24 of 30 cases (80%). The mean Oxford Elbow Score was 44.32. The mean follow-up was 40.11 months. The complications seen were radiocapitellar joint penetration - 6 cases at mean 4.87 weeks, redisplacement - 6, radial epiphyseal sclerosis - 5, and heterotopic ossification 1 case. Conclusion: lntramedullary K wires may result in radiocapitellar joint penetration. Titanium Elastic Nail System should not be used as purely fixation devices as they may not prevent redisplacement. Regular follow-up until at least 6 weeks is essential. Patients who have a Judet IV fracture and need open reduction should be given a guarded prognosis. The paper highlights the pitfalls of the technique and makes recommendations regarding the type of implant, follow-up and patient counselling in Judet IV fractures.展开更多
基金Under the auspices of National Youth Science Foundation of China(No.41001294)Key Project of National Natural Science Foundation of China(No.40930531)Research Fund of State Key Laboratory Resources and Environment Information System(No.2010KF0002SA)
文摘In China′s Loess Plateau area, gully head is the most active zone of a drainage system in gully areas. The differentiation of loess gully head follows geospatial patterns and reflects the process of the loess landform development and evolution of its drainage system to some extent. In this study, the geomorphic meaning, basic characteristics, morphological structure and the basic types of loess gully heads were systematically analysed. Then, the loess gully head′s conceptual model was established, and an extraction method based on Digital Elevation Model(DEM) for loess gully head features and elements was proposed. Through analysing the achieved statistics of loess gully head features, loess gully heads have apparently similar and different characteristics depending on the different loess landforms where they are found. The loess head characteristics reflect their growth period and evolution tendency to a certain degree, and they indirectly represent evolutionary mechanisms. In addition, the loess gully developmental stages and the evolutionary processes can be deduced by using loess gully head characteristics. This study is of great significance for development and improvement of the theoretical system for describing loess gully landforms.
基金supported by the National Natural Science Foundation of China project (Grant Nos. 41201130, 41101361, and 41371183)
文摘Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention. This paper explored the symmetry between physical and human systems through fractal analysis of the road and drainage networks in Wuling mountainous area. We found that both the road and drainage networks reflect weak clustering distributions. The evolution of the road network shared a significant self-organizing composition, while the drainage network showed obvious double fraetal characteristics. The geometric fractal dimension of the road network was larger than that of the drainage network. In addition, when assigned a weight relating to hierarchy or length, neither the road network nor drainage network showed a fractal property. These findings indicated that the fractal evolution of the road network shared certain similarities with fractal distribution of the drainage network. The symmetry between the two systems resulted from an interactive process of destroying symmetry at the lower order and reconstructing symmetry at the higher order. The relationships between the fractal dimensions of the rural-urban road network, the drainage network andthe urban system indicated that the development of this area was to achieve the symmetrical isomorphism of physical-human geographical systems.
文摘The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe (sewage and branch pipes respectively) which can be into other houses without going through floors! This technology has many advantages, like easy to construct and install at the same floor on one hand; on the other hand, when sewage or waste reach the top compared with the same kind drainage systems and other drainage methods, it can smoothly enter the main pipe (the chief vertical one). Moreover, once there is any situation needing dredge and cleaning, this problem can be solved at the same floor without interrupting the lives of other families. Last but not the least, it is so convenient to create a clean and tidy washing room. The branch pipe without being through floors is the very reason to solve the problem of surface condensation relative to sewage pipe in the rainy days, which correspondingly increases the hcight of head room indoor, is more favorable for fire prevention and much easier to keep smooth pipe flow.
文摘The Tunisian oases face serious problems of waterlogging and salinization caused by mismanagement of water and soil resources and the reduced discharge of drainage water. The oases space is based on a fragile balance between water, soil and man, which is now changed by modem irrigation and drainage systems. The oases pump most of their water from deep aquifers and only to a small degree from shallow aquifers. The quality of the irrigation water and the presence of a shallow saline water table are the main causes of salinization of the oases. Concerning the salt-affected landscapes and hydro-saline dynamic, the authors distinguish an equilibrium dynamic of salts to the parcel which depends on water management, and an equilibrium dynamic at the level of the basin watershed which is powered by drilling and ending in hypersaline depressions. For the management of salinization and waterlogging, a combination of agricultural management techniques are used, the first being modem methods of irrigation and drainage. Other, less used methods are sandy amendment, the reuse of drainage waters, geothermal waters and of treated wastewater.
基金Projects 40371113 supported by the National Natural Science Foundation of ChinaOF060096 by the Youth Scientific Foundation of China University of Mining & Technology
文摘To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of quantitative regulations of urban underlying surface rainfall infiltration conditions and a practical application of a simulated experimental system.In a com- prehensive analysis of the composition of an effective rainwater harvesting system and selection of water storage material,we simulated the major parameters of an experimental area rainfall,soil moisture and water storage capacity by providing an effective regulation of the experimental area runoff coefficient,obtained from basic data.
文摘Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. Methods: Thirty patients with isolated Judet III and IV fractures were included in this prospective study. Judet I and II fractures and radial neck fractures associated with other injuries were excluded. The final results were graded using the Metaizeau functional scoring system and Oxford Elbow Score. Results: The functional result was good to excellent in 24 of 30 cases (80%). The mean Oxford Elbow Score was 44.32. The mean follow-up was 40.11 months. The complications seen were radiocapitellar joint penetration - 6 cases at mean 4.87 weeks, redisplacement - 6, radial epiphyseal sclerosis - 5, and heterotopic ossification 1 case. Conclusion: lntramedullary K wires may result in radiocapitellar joint penetration. Titanium Elastic Nail System should not be used as purely fixation devices as they may not prevent redisplacement. Regular follow-up until at least 6 weeks is essential. Patients who have a Judet IV fracture and need open reduction should be given a guarded prognosis. The paper highlights the pitfalls of the technique and makes recommendations regarding the type of implant, follow-up and patient counselling in Judet IV fractures.