In the meizoseismal areas hit by the China Wenchuan earthquake on May 12, 2008, the disasterprone environment has changed dramatically, making the susceptibility assessment of debris flow more complex and uncertain. A...In the meizoseismal areas hit by the China Wenchuan earthquake on May 12, 2008, the disasterprone environment has changed dramatically, making the susceptibility assessment of debris flow more complex and uncertain. After the earthquake, debris flow hazards occurred frequently and effective susceptibility assessment of debris flow has become extremely important. Shenxi gully in Du Jiangyan city, located in the meizoseismal areas, was selected as the study area. Based on the research of disaster-prone environment and the main factors controlling debris flow, the susceptibility zonations of debris flow were mapped using factor weight method(FW), certainty coefficient method(CF) and geomorphic information entropy method(GI). Through comparative analysis, the study showed that these three methods underestimated susceptible degree of debris flow when used in the meizoseismal areas of Wenchuan earthquake. In order to solve this problem, this paper developed a modified certainty coefficient method(M-CF) to reflect the impact of rich loose materials on the susceptible degree of debris flow. In the modified method, the distribution and area of loose materials were obtained by field investigations and postearthquake remote sensing image, and four data sets, namely, lithology, elevation, slop and aspect, wereused to calculate the CF values. The result of M-CF method is in agreement with field investigations and the accuracy of the method is satisfied. The method has a wide application to the susceptibility assessment of debris flow in the earthquake stricken areas.展开更多
目的观察不同通气方法对老年全麻俯卧位脊柱手术患者围术期呼吸功能的影响。方法选择拟在全麻俯卧位下行腰骶椎手术的老年患者60例,ASAⅠ或Ⅱ级,性别不限,年龄65∽75岁,体重50∽80 kg,体重指数≤25 kg/m2;采用随机法,将其分为3组,每组2...目的观察不同通气方法对老年全麻俯卧位脊柱手术患者围术期呼吸功能的影响。方法选择拟在全麻俯卧位下行腰骶椎手术的老年患者60例,ASAⅠ或Ⅱ级,性别不限,年龄65∽75岁,体重50∽80 kg,体重指数≤25 kg/m2;采用随机法,将其分为3组,每组20例：C组（Vt：10 m L/kg）、LV组（Vt：6 m L/kg）和LV＋PEEP组（Vt：6 m L/kg,PEEP：5 cm H2O）。记录麻醉前（T0）、气管插管后仰卧位机械通气10 min（T1）、气管插管后俯卧位机械通气10 min（T2）、气管插管后俯卧位机械通气60 min（T3）、气管拔管后脱氧30 min（T4）的血流动力学指标、血气分析指标及呼吸力学指标。结果三组患者HR、MAP比较差异无统计学意义（P〉0.05）;与LV组同时点比较,C组及LV＋PEEP组机械通气期间Ppeak、Pmean较高（P〈0.05）,但LV＋PEEP组与C组比较,差异无统计学意义（P〉0.05）;LV组及LV＋PEEP组Cldyn明显高于同时点C组（P〈0.05）,但三组患者Cldyn均随着通气时间延长呈下降趋势,其中LV组与LV＋PEEP组差异无统计学意义（P〉0.05）;在T4时点,LV＋PEEP组Pa O2/Fi O2明显高于C组及LV组,A-a DO2低于C组及LV组,差异有统计学意义（P〈0.05）。结论小潮气量联合低水平PEEP（6 m L/kg＋5 cm H2O PEEP）通气能够有效改善全麻俯卧位脊柱手术老年患者术后氧合,提高肺的顺应性,有利于此类手术老年患者呼吸功能的恢复,而且对血流动力学无明显影响。展开更多
基金Financial support was provided by Ministry of Water Resources welfare industry funding(Grant No.201301058)Key Laboratory of Mountain Hazards and Earth Surface Processes independent project funding:Dynamic process and buried risk of debris flow in Shenxi gully after Wenchuan earthquakethe international cooperation project of Ministry of Science and Technology(Grant No.2013DFA21720)
文摘In the meizoseismal areas hit by the China Wenchuan earthquake on May 12, 2008, the disasterprone environment has changed dramatically, making the susceptibility assessment of debris flow more complex and uncertain. After the earthquake, debris flow hazards occurred frequently and effective susceptibility assessment of debris flow has become extremely important. Shenxi gully in Du Jiangyan city, located in the meizoseismal areas, was selected as the study area. Based on the research of disaster-prone environment and the main factors controlling debris flow, the susceptibility zonations of debris flow were mapped using factor weight method(FW), certainty coefficient method(CF) and geomorphic information entropy method(GI). Through comparative analysis, the study showed that these three methods underestimated susceptible degree of debris flow when used in the meizoseismal areas of Wenchuan earthquake. In order to solve this problem, this paper developed a modified certainty coefficient method(M-CF) to reflect the impact of rich loose materials on the susceptible degree of debris flow. In the modified method, the distribution and area of loose materials were obtained by field investigations and postearthquake remote sensing image, and four data sets, namely, lithology, elevation, slop and aspect, wereused to calculate the CF values. The result of M-CF method is in agreement with field investigations and the accuracy of the method is satisfied. The method has a wide application to the susceptibility assessment of debris flow in the earthquake stricken areas.
文摘目的观察不同通气方法对老年全麻俯卧位脊柱手术患者围术期呼吸功能的影响。方法选择拟在全麻俯卧位下行腰骶椎手术的老年患者60例,ASAⅠ或Ⅱ级,性别不限,年龄65∽75岁,体重50∽80 kg,体重指数≤25 kg/m2;采用随机法,将其分为3组,每组20例：C组（Vt：10 m L/kg）、LV组（Vt：6 m L/kg）和LV＋PEEP组（Vt：6 m L/kg,PEEP：5 cm H2O）。记录麻醉前（T0）、气管插管后仰卧位机械通气10 min（T1）、气管插管后俯卧位机械通气10 min（T2）、气管插管后俯卧位机械通气60 min（T3）、气管拔管后脱氧30 min（T4）的血流动力学指标、血气分析指标及呼吸力学指标。结果三组患者HR、MAP比较差异无统计学意义（P〉0.05）;与LV组同时点比较,C组及LV＋PEEP组机械通气期间Ppeak、Pmean较高（P〈0.05）,但LV＋PEEP组与C组比较,差异无统计学意义（P〉0.05）;LV组及LV＋PEEP组Cldyn明显高于同时点C组（P〈0.05）,但三组患者Cldyn均随着通气时间延长呈下降趋势,其中LV组与LV＋PEEP组差异无统计学意义（P〉0.05）;在T4时点,LV＋PEEP组Pa O2/Fi O2明显高于C组及LV组,A-a DO2低于C组及LV组,差异有统计学意义（P〈0.05）。结论小潮气量联合低水平PEEP（6 m L/kg＋5 cm H2O PEEP）通气能够有效改善全麻俯卧位脊柱手术老年患者术后氧合,提高肺的顺应性,有利于此类手术老年患者呼吸功能的恢复,而且对血流动力学无明显影响。
基金Project(2015CX005)supported by the Innovation Driven Plan of Central South University of ChinaProject supported by the Sheng Hua Lie Ying Program of Central South University,China
