The structural features of soil in debris flow-triggering region play an important role in the formation and evolution of debris flow. In this paper, a case study on the fractal of soil particle-size distribution （PS...The structural features of soil in debris flow-triggering region play an important role in the formation and evolution of debris flow. In this paper, a case study on the fractal of soil particle-size distribution （PSDFs） and pore-solid （PSFs） in Jiangjia Ravine was conducted. The results revealed that the soil in Jiangjia Ravine had significant fractal features and its PSDF and PSF had the same variation trend despite different type of soils in debris flow-triggering region： residual soil （RS） 〉 debris flow deposit （DFD）~clinosol （CL）, their fractal dimension of PSDFs are respectively between 2.62 and 2.96, 2.52 and 2.68, 2.37 and 2.52; and the fractal dimension of PSFs are respectively between 2. 75 and 2.95, 2. 57 and 2. 72, 2.59 and 2.64. The fractal dimension of soil reflected its complexity as a self-organizing system and was closely related to the evolution of soil in debris flow- triggering region.展开更多
Previous studies suggest that there are three different jam phases in the cellular automata automaton model with a slow-to-start rule under open boundaries.In the present paper,the dynamics of each free-flow-jam phase...Previous studies suggest that there are three different jam phases in the cellular automata automaton model with a slow-to-start rule under open boundaries.In the present paper,the dynamics of each free-flow-jam phase transition is studied.By analysing the microscopic behaviour of the traffic flow,we obtain analytical results on the phase transition dynamics.Our results can describe the detailed time evolution of the system during phase transition,while they provide good approximation for the numerical simulation data.These findings can perfectly explain the microscopic mechanism and details of the boundary-triggered phase transition dynamics.展开更多
目的探讨不同吸气触发方式对新生儿重症监护病房(neonatal intensive care unit,NICU)机械通气患儿动脉血气、撤机成功率和传感器故障率的影响。方法选取2018年8月至2023年3月高安市人民医院NICU收治的80例机械通气患儿作为研究对象,按...目的探讨不同吸气触发方式对新生儿重症监护病房(neonatal intensive care unit,NICU)机械通气患儿动脉血气、撤机成功率和传感器故障率的影响。方法选取2018年8月至2023年3月高安市人民医院NICU收治的80例机械通气患儿作为研究对象,按照随机数字表法分为压力触发组与流速触发组,每组40例。两组均进行机械通气干预,压力触发组设定为压力触发模式,流速触发组设定为流速触发模式。比较两组动脉血气指标[动脉血氧分压(arterial partial pressure of oxygen,PaO_(2))、动脉血二氧化碳分压(arterial partial pressure of carbon dioxide,PaCO_(2))、酸碱度(potential of hydrogen,pH)]、撤机成功率及传感器故障率。结果两组通气后12、24 h的PaO_(2)、pH值均高于通气前,且两组通气后24 h PaO_(2)及压力触发组pH值均高于通气后12 h,差异有统计学意义(P<0.05);两组通气后12、24 h的PaCO_(2)均低于通气前,且通气后24 h低于通气后12 h,差异有统计学意义(P<0.05)。通气前,两组PaO_(2)、PaCO_(2)、pH值比较差异无统计学意义;通气后12 h,流速触发组PaO_(2)高于压力触发组,PaCO_(2)低于压力触发组,差异有统计学意义(P<0.05),两组pH值差异比较无统计学意义;通气后24 h,流速触发组PaO_(2)高于压力触发组,PaCO_(2)、pH值均低于压力触发组差异有统计学意义(P<0.05)。两组撤机成功率比较差异无统计学意义。压力触发组传感器故障率为10.00%,低于流速触发组的30.00%,差异有统计学意义(P<0.05)。结论流速触发更利于改善NICU机械通气患儿的动脉血气指标,但压力触发传感器故障率更低,二者对撤机的影响无显著差异,临床可根据需求进行吸气触发模式选择。展开更多
文摘The structural features of soil in debris flow-triggering region play an important role in the formation and evolution of debris flow. In this paper, a case study on the fractal of soil particle-size distribution （PSDFs） and pore-solid （PSFs） in Jiangjia Ravine was conducted. The results revealed that the soil in Jiangjia Ravine had significant fractal features and its PSDF and PSF had the same variation trend despite different type of soils in debris flow-triggering region： residual soil （RS） 〉 debris flow deposit （DFD）~clinosol （CL）, their fractal dimension of PSDFs are respectively between 2.62 and 2.96, 2.52 and 2.68, 2.37 and 2.52; and the fractal dimension of PSFs are respectively between 2. 75 and 2.95, 2. 57 and 2. 72, 2.59 and 2.64. The fractal dimension of soil reflected its complexity as a self-organizing system and was closely related to the evolution of soil in debris flow- triggering region.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 70971094 and 50908155)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT)
文摘Previous studies suggest that there are three different jam phases in the cellular automata automaton model with a slow-to-start rule under open boundaries.In the present paper,the dynamics of each free-flow-jam phase transition is studied.By analysing the microscopic behaviour of the traffic flow,we obtain analytical results on the phase transition dynamics.Our results can describe the detailed time evolution of the system during phase transition,while they provide good approximation for the numerical simulation data.These findings can perfectly explain the microscopic mechanism and details of the boundary-triggered phase transition dynamics.
文摘目的探讨不同吸气触发方式对新生儿重症监护病房(neonatal intensive care unit,NICU)机械通气患儿动脉血气、撤机成功率和传感器故障率的影响。方法选取2018年8月至2023年3月高安市人民医院NICU收治的80例机械通气患儿作为研究对象,按照随机数字表法分为压力触发组与流速触发组,每组40例。两组均进行机械通气干预,压力触发组设定为压力触发模式,流速触发组设定为流速触发模式。比较两组动脉血气指标[动脉血氧分压(arterial partial pressure of oxygen,PaO_(2))、动脉血二氧化碳分压(arterial partial pressure of carbon dioxide,PaCO_(2))、酸碱度(potential of hydrogen,pH)]、撤机成功率及传感器故障率。结果两组通气后12、24 h的PaO_(2)、pH值均高于通气前,且两组通气后24 h PaO_(2)及压力触发组pH值均高于通气后12 h,差异有统计学意义(P<0.05);两组通气后12、24 h的PaCO_(2)均低于通气前,且通气后24 h低于通气后12 h,差异有统计学意义(P<0.05)。通气前,两组PaO_(2)、PaCO_(2)、pH值比较差异无统计学意义;通气后12 h,流速触发组PaO_(2)高于压力触发组,PaCO_(2)低于压力触发组,差异有统计学意义(P<0.05),两组pH值差异比较无统计学意义;通气后24 h,流速触发组PaO_(2)高于压力触发组,PaCO_(2)、pH值均低于压力触发组差异有统计学意义(P<0.05)。两组撤机成功率比较差异无统计学意义。压力触发组传感器故障率为10.00%,低于流速触发组的30.00%,差异有统计学意义(P<0.05)。结论流速触发更利于改善NICU机械通气患儿的动脉血气指标,但压力触发传感器故障率更低,二者对撤机的影响无显著差异,临床可根据需求进行吸气触发模式选择。
