Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which t...Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which th e length-radius dimension describes change of network density,and ramification-radius dimension describes complexity and accessibility of urban network.It i s propitious to analyze urban traffic network and to understand dynamic c hange process of traffic network using expanding f ractal-dimension quantification.Meanwhile the length-radius dimension and ramifica-tion-radius dimension could be rega rd as reference factor of quantitative describing urban traffic network.展开更多
Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and ...Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and 7.61 in 2006 and 2007, respectively. In the meltwater, the dominant anions were the bicarbonate and sulphate, and the dominant cation was calcium. The concentration of major cations were varied as c（Ca2＋） 〉 c（Mg2＋） 〉 c（K＋） 〉 c（Na＋）, while the order for the cations was c（HCO3-） 〉 c（SO42-） 〉 c（NQ-） 〉 c（C1-）. The total dissolved solids （TDS） in meltwater had inverse relationships with the diurnal discharge. The major ion composition of meltwater was mainly controlled by rock weathering as inferred from the Gibbs model. Furthermore, the ion ratios and Piper diagram indicated that the main processes controlling the meltwater chemistry were carbonate weathering, pyrite weathering and feldspar weathering in rocks, and Ca2＋ and HCQ- were the dominant ions during the carbonate weathering process. Solute flux calculation at Glacier No.1 station suggested that chemical denudation rates were 11.46 and 13.90 tonkm-2.yr-1 in 2006 and 2007, respectively.展开更多
An experimental study was conducted to investigate the 2 D bubbly flow downstream of a cylinder. Sparsely distributed bubbles were produced using the ventilation method. The carrier flow was measured using the particl...An experimental study was conducted to investigate the 2 D bubbly flow downstream of a cylinder. Sparsely distributed bubbles were produced using the ventilation method. The carrier flow was measured using the particle image velocimetry(PIV) technique. The shadow imaging technique was used to capture instantaneous bubbly flow images. An image-processing code was compiled to identify bubbles in acquired image, calculate the bubble equivalent diameter and the bubble velocity. The effects of Reynolds number and the flow rate of the injected air were considered. The result indicates that the carrier flow is featured by distinct flow structures and the wake region is suppressed as the upstream velocity increases. Regarding the bubbles trapped in the wake flow, the number of small bubbles increases with the upstream velocity. On the whole, the bubble velocity is slightly lower than that of the carrier flow. The consistency between small bubbles and the carrier flow is high in terms of velocity magnitude, which is justified near the wake edge. The difference between the bubble velocity and the carrier flow velocity is remarkable near the wake centerline. For certain Reynolds number, with the increase in the air flow rate, the bubble equivalent diameter increases and the bubble void fraction is elevated.展开更多
Objective： To determine the epidemio logical characteristics of fatal pedestrian accidents in Fats Province of Iran. Methods： This crosssectional study was conducted in Fats Province of Iran during a 29month period...Objective： To determine the epidemio logical characteristics of fatal pedestrian accidents in Fats Province of Iran. Methods： This crosssectional study was conducted in Fats Province of Iran during a 29month period from March 2009 to July 2011. The data were from the Fats Forensic Medi cine Registry, In 4 923 recorded road traffic accident fatalities, 971 deaths were due to pedestrian accidents. The demographic and accidentrelated information were analyzed by SPSS ver sion 11.5. P value less than 0.05 was considered significant. Results： The mean age of decedents was （47.2±26.2） years, ranging from 6 months to 103 years old. Males ac counted for 69.8% of all deaths. Fatal accidents were mostcommon in September; 56.1% of the fatal injuries occurred on intracity roads and 33.1% on extracity roads. Fatal head injuries were present in 60.54% of cases. Evaluation of the injury site and the cause of death found that they were significantly associated with age, interval between injury and death. Besides, the type of roads played an important role in mortality. Conclusion： Although the clinical management of trauma patients has been improved in our country in the recent decade, decreasing the burden of injuries needs co ordination among trauma system organizations.展开更多
：Objective：To study the epidemiologic characteristics of traffic injuries among people over 60 years old in the Nan＇ an district（urban）and Jiangjin district（rural）of Chongqing,and to discuss the corresponding s...：Objective：To study the epidemiologic characteristics of traffic injuries among people over 60 years old in the Nan＇ an district（urban）and Jiangjin district（rural）of Chongqing,and to discuss the corresponding strategies for its prevention and cure.Methods：Records of traffic injuries in people over 60 years old registered by the traffic police between 2000 and 2006 in Nan＇an district and Jiangjin district were collected in the Database of Road Traffic Accidents and Traffic Injuries.Epidemiologic characteristics of traffic injuries among the aged people were analyzed and compared.Results：Between the year 2000 and 2006,the average annual incidence of traffic injuries and mortality rate in the aged people in Nan＇ an district were 124.62/100 000 and 13.85/100 000 respectively,higher than that in Jiangjin district（27.49/100 000,7.13/100 000,P〈0.01）.However,the mortality rate for the aged people who were involved in traffic injuries in Jiangjin district was 20.60%,higher than that in Nan＇an district（10.00%,P〈0.01）.Head injury was the primary cause of death.Totally 76.58% of casualties were pedestrians.Over 90% of the traffic accidents occurred in the areas with no traffic signal or traffic control system.Conclusions：The traffic environment is unfavorable to the aged people.It is important to enhance traffic safety consciousness of drivers and the elderly and to strengthen traffic safety system and traffic law,so as to provide a safe road traffic environment for the aged people.展开更多
文摘Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which th e length-radius dimension describes change of network density,and ramification-radius dimension describes complexity and accessibility of urban network.It i s propitious to analyze urban traffic network and to understand dynamic c hange process of traffic network using expanding f ractal-dimension quantification.Meanwhile the length-radius dimension and ramifica-tion-radius dimension could be rega rd as reference factor of quantitative describing urban traffic network.
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX2-EW-311)the National Natural Science Foundation of China(Nos. 91025012,40701034,J0630966/J0109, 40701035)+1 种基金the SKLCS founding(SKLCS-ZZ-201004,SKLCS-ZZ-2012-01-01)the Foundation for Excellent Youth Scholars of CAREERI,Chinese Academy of Sciences(Y184C81001)
文摘Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and 7.61 in 2006 and 2007, respectively. In the meltwater, the dominant anions were the bicarbonate and sulphate, and the dominant cation was calcium. The concentration of major cations were varied as c（Ca2＋） 〉 c（Mg2＋） 〉 c（K＋） 〉 c（Na＋）, while the order for the cations was c（HCO3-） 〉 c（SO42-） 〉 c（NQ-） 〉 c（C1-）. The total dissolved solids （TDS） in meltwater had inverse relationships with the diurnal discharge. The major ion composition of meltwater was mainly controlled by rock weathering as inferred from the Gibbs model. Furthermore, the ion ratios and Piper diagram indicated that the main processes controlling the meltwater chemistry were carbonate weathering, pyrite weathering and feldspar weathering in rocks, and Ca2＋ and HCQ- were the dominant ions during the carbonate weathering process. Solute flux calculation at Glacier No.1 station suggested that chemical denudation rates were 11.46 and 13.90 tonkm-2.yr-1 in 2006 and 2007, respectively.
基金Supported by the National Natural Science Foundation of China(51676087)
文摘An experimental study was conducted to investigate the 2 D bubbly flow downstream of a cylinder. Sparsely distributed bubbles were produced using the ventilation method. The carrier flow was measured using the particle image velocimetry(PIV) technique. The shadow imaging technique was used to capture instantaneous bubbly flow images. An image-processing code was compiled to identify bubbles in acquired image, calculate the bubble equivalent diameter and the bubble velocity. The effects of Reynolds number and the flow rate of the injected air were considered. The result indicates that the carrier flow is featured by distinct flow structures and the wake region is suppressed as the upstream velocity increases. Regarding the bubbles trapped in the wake flow, the number of small bubbles increases with the upstream velocity. On the whole, the bubble velocity is slightly lower than that of the carrier flow. The consistency between small bubbles and the carrier flow is high in terms of velocity magnitude, which is justified near the wake edge. The difference between the bubble velocity and the carrier flow velocity is remarkable near the wake centerline. For certain Reynolds number, with the increase in the air flow rate, the bubble equivalent diameter increases and the bubble void fraction is elevated.
文摘Objective： To determine the epidemio logical characteristics of fatal pedestrian accidents in Fats Province of Iran. Methods： This crosssectional study was conducted in Fats Province of Iran during a 29month period from March 2009 to July 2011. The data were from the Fats Forensic Medi cine Registry, In 4 923 recorded road traffic accident fatalities, 971 deaths were due to pedestrian accidents. The demographic and accidentrelated information were analyzed by SPSS ver sion 11.5. P value less than 0.05 was considered significant. Results： The mean age of decedents was （47.2±26.2） years, ranging from 6 months to 103 years old. Males ac counted for 69.8% of all deaths. Fatal accidents were mostcommon in September; 56.1% of the fatal injuries occurred on intracity roads and 33.1% on extracity roads. Fatal head injuries were present in 60.54% of cases. Evaluation of the injury site and the cause of death found that they were significantly associated with age, interval between injury and death. Besides, the type of roads played an important role in mortality. Conclusion： Although the clinical management of trauma patients has been improved in our country in the recent decade, decreasing the burden of injuries needs co ordination among trauma system organizations.
文摘：Objective：To study the epidemiologic characteristics of traffic injuries among people over 60 years old in the Nan＇ an district（urban）and Jiangjin district（rural）of Chongqing,and to discuss the corresponding strategies for its prevention and cure.Methods：Records of traffic injuries in people over 60 years old registered by the traffic police between 2000 and 2006 in Nan＇an district and Jiangjin district were collected in the Database of Road Traffic Accidents and Traffic Injuries.Epidemiologic characteristics of traffic injuries among the aged people were analyzed and compared.Results：Between the year 2000 and 2006,the average annual incidence of traffic injuries and mortality rate in the aged people in Nan＇ an district were 124.62/100 000 and 13.85/100 000 respectively,higher than that in Jiangjin district（27.49/100 000,7.13/100 000,P〈0.01）.However,the mortality rate for the aged people who were involved in traffic injuries in Jiangjin district was 20.60%,higher than that in Nan＇an district（10.00%,P〈0.01）.Head injury was the primary cause of death.Totally 76.58% of casualties were pedestrians.Over 90% of the traffic accidents occurred in the areas with no traffic signal or traffic control system.Conclusions：The traffic environment is unfavorable to the aged people.It is important to enhance traffic safety consciousness of drivers and the elderly and to strengthen traffic safety system and traffic law,so as to provide a safe road traffic environment for the aged people.
