To better understand the mechanism of the Mw6.3 L＇Aquila （Central Italy） earthquake occurred in 2009, global positioning system （GPS） and interferometric synthetic aperture radar （InSAR） data were used to deriv...To better understand the mechanism of the Mw6.3 L＇Aquila （Central Italy） earthquake occurred in 2009, global positioning system （GPS） and interferometric synthetic aperture radar （InSAR） data were used to derive the coseismic slip distribution of the earthquake fault. Firstly, based on the homogeneous elastic half-space model, the fault geometric parameters were solved by the genetic algorithm. The best fitting model shows that the fault is a 13.7 km×14.1 km rectangular fault, in 139.3° strike direction and 50.2° southwest-dipping. Secondly, fixing the optimal fault geometric parameters, the fault plane was extended and discretized into 16× 16 patches, each with a size of 1 kmx 1 krn, and the non-uniform slip distribution of the fault was inverted by the steepest descent method with an appropriate smoothing ratio based on the layered crustal structure model. The preferred solution shows that the fault is mainly a normal fault with slight right-lateral strike slip, the maximum slip of 1.01 m is located in the depth of 8.28 km, the average rake is -100.9°, and the total geodetic moment is about 3.34× 1018 N.m （Mw 6.28）. The results are much closer than previous studies in comparison with the seismological estimation. These demonstrate that the coseismic fault slip distribution of the L＇Aauila earthauake inverted by the crustal model considering layered characters is reliable.展开更多
The ages of organic matter of some dark-colored horizons and calcareous concretions in some Vertisols from tropical, subtropical and warm-temperate zones of China were studied using radiocarb on dating method. The rel...The ages of organic matter of some dark-colored horizons and calcareous concretions in some Vertisols from tropical, subtropical and warm-temperate zones of China were studied using radiocarb on dating method. The relationship between soil age and genesis of Vertisols was also expounded based on the study of their genetic charactens-tics and micromorphological features. The results show that although Vertisols have developed for a relatively long time, their weathering and soil forming process are weak and young with little horizonation. This is closely related to their special geochemical soil forming environment. Low-lying terrain, heavy texture, clay minerals dominated by montmorillonites and alternative drying- wetting climate give rise to the vertic features expressed in intense swelling-shrinking and cracking-closing in soils. As a result, the soil development and soil leaching process are resisted, and the climatic effect on the horizonation is impeded. Moreover, pedoturbation eliminates the horizonation in the upper part of soil profile, and postpones their evolution into zonal soils. So Vertisols show certain pedogenic inertia and stay at relatively young developmental stage. Therefore, Vertisols are intrazonal soils dominated by local soil forming factors such as the relief and parent materials.展开更多
Hyalella azteca was used to assess biological impairment in sediments from nine water bodies in the Mississippi Delta （i.e., lower Mississippi alluvial plain）. Water bodies were categorized according to land use and...Hyalella azteca was used to assess biological impairment in sediments from nine water bodies in the Mississippi Delta （i.e., lower Mississippi alluvial plain）. Water bodies were categorized according to land use and implementation of agricultural best management practices （BMPs）. Sediment samples were collected at three sites within each water body from June to July 2004 and analyzed for 17 current and historic-use pesticides and metabolites. Twenty-eight day H. azteca survival and growth were measured to assess the degree of biological impairment. No significant （P 〉 0.05） mortality occurred in animals exposed to sediments. Significant growth impairment was observed in sediments from all three 303（d） listed water bodies and two of three BMP oxbow lakes. Historic-use pesticides and metabolites were implicated in two of five biologically impaired water bodies. Complex contaminant mixtures often limit attempts to provide clear, definitive sources of biological impairment. In this study, even accounting for sediment characteristics such as sand-silt-clay fractions and organic carbon content did not further clarify sources of toxicity in some water bodies. Finally, results show that implementation of BMPs can mitigate biological impairment within lake sediments.展开更多
The Universal Declaration of Human Rights refers to the human right to health and well-being including medical care, but for the majority of people whom are not covered by health insurance this is better said than don...The Universal Declaration of Human Rights refers to the human right to health and well-being including medical care, but for the majority of people whom are not covered by health insurance this is better said than done. Ensuring the access of all citizens to the needed medical care requires the provision of health insurance coverage to a population pool and gradually expanding the pool to the whole nation. The ethical perspective of pooling resources across various groups of people with different levels of income and different health risks associated with age, genetics, and lifestyle, may raise the issue of individual autonomy versus social solidarity. Governmental, social, private, and community-based healthcare coverage have been used in different countries with varying details in the sources of funding, pooling of contributions, and the purchase of the covered healthcare services; these models have had varying levels of success depending on not only the availability of funds, but also on the political commitment of the state and the social solidarity and cultural attitude of the population towards universal healthcare. Therefore, universal healthcare requires not only a certain level of economic development, but also a strong sense of solidarity among the people as well as a political commitment in their government. I argue that the statement regarding the right to health, well-being, and medical care needs to be rethought, and instead universal access to essential healthcare should be regarded as a basic human right.展开更多
基金Projects(40974006,40774003) supported by the National Natural Science Foundation of ChinaProject(NCET-08-0570) supported by the Program for New Century Excellent Talents in Chinese Universities+2 种基金Projects(2011JQ001,2009QZZD004) supported by the Fundamental Research Funds for the Central Universities in ChinaProjects(09K005,09K006) supported by the Key Laboratory for Precise Engineering Surveying & Hazard Monitoring of Hunan Province,ChinaProject(1343-74334000023) supported by the Graduate DegreeThesis Innovation Foundation of Central South University,China
文摘To better understand the mechanism of the Mw6.3 L＇Aquila （Central Italy） earthquake occurred in 2009, global positioning system （GPS） and interferometric synthetic aperture radar （InSAR） data were used to derive the coseismic slip distribution of the earthquake fault. Firstly, based on the homogeneous elastic half-space model, the fault geometric parameters were solved by the genetic algorithm. The best fitting model shows that the fault is a 13.7 km×14.1 km rectangular fault, in 139.3° strike direction and 50.2° southwest-dipping. Secondly, fixing the optimal fault geometric parameters, the fault plane was extended and discretized into 16× 16 patches, each with a size of 1 kmx 1 krn, and the non-uniform slip distribution of the fault was inverted by the steepest descent method with an appropriate smoothing ratio based on the layered crustal structure model. The preferred solution shows that the fault is mainly a normal fault with slight right-lateral strike slip, the maximum slip of 1.01 m is located in the depth of 8.28 km, the average rake is -100.9°, and the total geodetic moment is about 3.34× 1018 N.m （Mw 6.28）. The results are much closer than previous studies in comparison with the seismological estimation. These demonstrate that the coseismic fault slip distribution of the L＇Aauila earthauake inverted by the crustal model considering layered characters is reliable.
文摘The ages of organic matter of some dark-colored horizons and calcareous concretions in some Vertisols from tropical, subtropical and warm-temperate zones of China were studied using radiocarb on dating method. The relationship between soil age and genesis of Vertisols was also expounded based on the study of their genetic charactens-tics and micromorphological features. The results show that although Vertisols have developed for a relatively long time, their weathering and soil forming process are weak and young with little horizonation. This is closely related to their special geochemical soil forming environment. Low-lying terrain, heavy texture, clay minerals dominated by montmorillonites and alternative drying- wetting climate give rise to the vertic features expressed in intense swelling-shrinking and cracking-closing in soils. As a result, the soil development and soil leaching process are resisted, and the climatic effect on the horizonation is impeded. Moreover, pedoturbation eliminates the horizonation in the upper part of soil profile, and postpones their evolution into zonal soils. So Vertisols show certain pedogenic inertia and stay at relatively young developmental stage. Therefore, Vertisols are intrazonal soils dominated by local soil forming factors such as the relief and parent materials.
文摘Hyalella azteca was used to assess biological impairment in sediments from nine water bodies in the Mississippi Delta （i.e., lower Mississippi alluvial plain）. Water bodies were categorized according to land use and implementation of agricultural best management practices （BMPs）. Sediment samples were collected at three sites within each water body from June to July 2004 and analyzed for 17 current and historic-use pesticides and metabolites. Twenty-eight day H. azteca survival and growth were measured to assess the degree of biological impairment. No significant （P 〉 0.05） mortality occurred in animals exposed to sediments. Significant growth impairment was observed in sediments from all three 303（d） listed water bodies and two of three BMP oxbow lakes. Historic-use pesticides and metabolites were implicated in two of five biologically impaired water bodies. Complex contaminant mixtures often limit attempts to provide clear, definitive sources of biological impairment. In this study, even accounting for sediment characteristics such as sand-silt-clay fractions and organic carbon content did not further clarify sources of toxicity in some water bodies. Finally, results show that implementation of BMPs can mitigate biological impairment within lake sediments.
文摘The Universal Declaration of Human Rights refers to the human right to health and well-being including medical care, but for the majority of people whom are not covered by health insurance this is better said than done. Ensuring the access of all citizens to the needed medical care requires the provision of health insurance coverage to a population pool and gradually expanding the pool to the whole nation. The ethical perspective of pooling resources across various groups of people with different levels of income and different health risks associated with age, genetics, and lifestyle, may raise the issue of individual autonomy versus social solidarity. Governmental, social, private, and community-based healthcare coverage have been used in different countries with varying details in the sources of funding, pooling of contributions, and the purchase of the covered healthcare services; these models have had varying levels of success depending on not only the availability of funds, but also on the political commitment of the state and the social solidarity and cultural attitude of the population towards universal healthcare. Therefore, universal healthcare requires not only a certain level of economic development, but also a strong sense of solidarity among the people as well as a political commitment in their government. I argue that the statement regarding the right to health, well-being, and medical care needs to be rethought, and instead universal access to essential healthcare should be regarded as a basic human right.
