The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydr...The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydroxide solution were performed using a universal testing machine （Monsanto tensometer）. The results from the tensile test indicate that stress is fairly proportional to strain. However, the tensile strength increases （reduction in strain）, as the soaking time increases for the treated composites. The untreated samples demonstrate reduced tensile strength compared to the treated composites under hygrothermal conditions. The conditioned samples in each case show better tensile and compressive strength compared to the untreated samples. The plant coconut fibres investigated demonstrate acceptable mechanical properties similar to the synthetic counterparts.展开更多
The quality changes of shallow groundwater from karst hilly areas in Guiyang region of China impacted by the urbanization were investigated. The results show that the major ions in shallow groundwater from the karst h...The quality changes of shallow groundwater from karst hilly areas in Guiyang region of China impacted by the urbanization were investigated. The results show that the major ions in shallow groundwater from the karst hilly areas are mainly composed of HCO3^-, SO4^2-, Ca^2＋ and Mg^2＋, and the concentrations scopes of NO3^-, Cl^-, K^＋ and Na^＋ of the groundwater in agricultural, residential and industrial areas are 4.5-9.6, 2.8-7.1, 3.9-6.3 and 2.5-4.9 times higher than those in the forest areas, respectively. The concentrations of As, Pb and Cd of shallow groundwater in the industrial areas are also significantly enhanced, followed by those in the residential areas and the agricultural areas. The concentrations of NO3^-, SO4^2- , As, Pb and Cd of the groundwater in the industrial areas and those of NO3^- , SO4^2-, As and Cd of shallow groundwater in the residential areas reach grade Ⅲ of the Groundwater Quality Standard of China （GB/T 14848-93）, while the concentration of NO3^- in the groundwater from the industrial areas exceeds grade V. With the process of urbanization, NO3^- is the key factor to influence the groundwater quality in karst hilly areas, followed by SO4^2-, As, Pb and Cd.展开更多
Wudu County in northwestern China frequently experiences large-scale landslide events. High-magnitude earthquakes and heavy rainfall events are the major triggering factors in the region. The aim of this research is t...Wudu County in northwestern China frequently experiences large-scale landslide events. High-magnitude earthquakes and heavy rainfall events are the major triggering factors in the region. The aim of this research is to compare and combine landslide suseeptibility assessments of rainfall- triggered and earthquake-triggered landslide events in the study area using Geographical Information System （GIS） and a logistic regression model. Two separate susceptibility maps were produeed using inventories reflecting single landslide-triggering events, i.e., earthquakes and heavy rain storms. Two groups of landslides were utilized： one group eontaining all landslides triggered by extreme rainfall events between 1995 and 2003 and the other group containing slope failures caused by the 2008 Wenchuan earthquake. Subsequently, the individual maps were combined to illustrate the loeations of maximum landslide probability. The use of the resulting three landslide susceptibility maps for landslide forecasting, spatial planning and for developing emergency response actions are discussed. The eombined susceptibility map illustrates the total landslide susceptibility in the study area.展开更多
文摘The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydroxide solution were performed using a universal testing machine （Monsanto tensometer）. The results from the tensile test indicate that stress is fairly proportional to strain. However, the tensile strength increases （reduction in strain）, as the soaking time increases for the treated composites. The untreated samples demonstrate reduced tensile strength compared to the treated composites under hygrothermal conditions. The conditioned samples in each case show better tensile and compressive strength compared to the untreated samples. The plant coconut fibres investigated demonstrate acceptable mechanical properties similar to the synthetic counterparts.
基金Project(2006CB403205) supported by the National Key Basic Research Program of ChinaProject(40961030) supported by the National Natural Science Foundation of China
文摘The quality changes of shallow groundwater from karst hilly areas in Guiyang region of China impacted by the urbanization were investigated. The results show that the major ions in shallow groundwater from the karst hilly areas are mainly composed of HCO3^-, SO4^2-, Ca^2＋ and Mg^2＋, and the concentrations scopes of NO3^-, Cl^-, K^＋ and Na^＋ of the groundwater in agricultural, residential and industrial areas are 4.5-9.6, 2.8-7.1, 3.9-6.3 and 2.5-4.9 times higher than those in the forest areas, respectively. The concentrations of As, Pb and Cd of shallow groundwater in the industrial areas are also significantly enhanced, followed by those in the residential areas and the agricultural areas. The concentrations of NO3^-, SO4^2- , As, Pb and Cd of the groundwater in the industrial areas and those of NO3^- , SO4^2-, As and Cd of shallow groundwater in the residential areas reach grade Ⅲ of the Groundwater Quality Standard of China （GB/T 14848-93）, while the concentration of NO3^- in the groundwater from the industrial areas exceeds grade V. With the process of urbanization, NO3^- is the key factor to influence the groundwater quality in karst hilly areas, followed by SO4^2-, As, Pb and Cd.
基金supported by the National Natural Science Foundation of China (Grant No.40930531)the National Key Technology R & D Program (Grant No. 2011BAK12B06)+1 种基金the Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection of Chengdu University of Technology (SKLGP2012K012)the Priority Academic Program Development of Jiangsu Higher Education Institutions, and the 51st Chinese PostDoc Science Foundation (Grant No. 2012M511298)
文摘Wudu County in northwestern China frequently experiences large-scale landslide events. High-magnitude earthquakes and heavy rainfall events are the major triggering factors in the region. The aim of this research is to compare and combine landslide suseeptibility assessments of rainfall- triggered and earthquake-triggered landslide events in the study area using Geographical Information System （GIS） and a logistic regression model. Two separate susceptibility maps were produeed using inventories reflecting single landslide-triggering events, i.e., earthquakes and heavy rain storms. Two groups of landslides were utilized： one group eontaining all landslides triggered by extreme rainfall events between 1995 and 2003 and the other group containing slope failures caused by the 2008 Wenchuan earthquake. Subsequently, the individual maps were combined to illustrate the loeations of maximum landslide probability. The use of the resulting three landslide susceptibility maps for landslide forecasting, spatial planning and for developing emergency response actions are discussed. The eombined susceptibility map illustrates the total landslide susceptibility in the study area.
