The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of...The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of one bionic spine and four pneumatic artificial muscles(PAMs).The coordinated movement of the bionic flexible body and the leg mechanism can achieve pivot turning gait.First,the pivot turning gait planning of quadruped robot was analyzed,and the coordinated movement sequence chart of pivot turning was presented.Then the kinematics modeling of leg side swing and body bending for pivot turning was derived,which should meet the condition of the coordinated movement between bionic flexible body and leg mechanism.The PAM experiment was conducted to analyze its contraction characteristic.The study on pivot turning of the quadruped robot will lay a theoretical foundation for the further research on dynamic walking stability of the quadruped robot in unstructured environment.展开更多
Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR （aryl hydrocarbon receptor） pathway, tobacco-similar pathway, oxidatio...Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR （aryl hydrocarbon receptor） pathway, tobacco-similar pathway, oxidation, as well as epigenetics pathway were reviewed. Based on the working mechanism, the reported study method and methodology used in Ashland lab were reviewed, including cell level experiment, through reconstructed human skin to in vivo study.展开更多
In order to improve efficiency of coal seam gas drainage, many fracturing techniques, such as waterjet fracturing, hydraulic fracturing and explosive fracturing, etc, have been developed and widely used in China coal ...In order to improve efficiency of coal seam gas drainage, many fracturing techniques, such as waterjet fracturing, hydraulic fracturing and explosive fracturing, etc, have been developed and widely used in China coal mining industry. How- ever, during the engineering applications, it is observed that the efficiency of gas drainage initially improves, but reduces there- after. Thus, it is speculated that the contrasts in coalbed methane drainage efficiency may reflect variation of the closure be- havior of the artificial fracture created. Based on comprehensive gas drainage monitoring data in underground coal mines, the work presented herein uses numerical simulation to show the behavior of the time-dependent closure of coal seam fractures as- sociated with various levels of waterjet fracturing parameters and geomechanical conditions.展开更多
The general idea of this work is to improve the performance of CAES （compressed air energy storage） for its application in solar and wind systems through a restitution technique by creating an artificial wind. The e...The general idea of this work is to improve the performance of CAES （compressed air energy storage） for its application in solar and wind systems through a restitution technique by creating an artificial wind. The efficiency of compressed air storage is often presented as a limit to its application. The present work describes a series of manipulations carried out in order to increase the yield. As the action of the artificial wind on the wind turbine is characterized by a reduced attack surface, a treated wind, a constant direction, an adjustable speed, it is therefore a question of acting on all the controllable parameters of the artificial wind to find the best way to use it to produce more energy from a certain quantity stored in a tank. The main manipulations consisted in determining： the optimal number of points of attack of the wind turbine; the nature of the action （continuous or interrupted） of the wind; the frequency of wind action and the duty cycle.展开更多
基金Supported by the National Natural Science Foundation of China(No.51375289)Shanghai Municipal National Natural Science Foundation of China(No.13ZR1415500)the Innovation Fund of Shanghai Education Commission(No.13YZ020)
文摘The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of one bionic spine and four pneumatic artificial muscles(PAMs).The coordinated movement of the bionic flexible body and the leg mechanism can achieve pivot turning gait.First,the pivot turning gait planning of quadruped robot was analyzed,and the coordinated movement sequence chart of pivot turning was presented.Then the kinematics modeling of leg side swing and body bending for pivot turning was derived,which should meet the condition of the coordinated movement between bionic flexible body and leg mechanism.The PAM experiment was conducted to analyze its contraction characteristic.The study on pivot turning of the quadruped robot will lay a theoretical foundation for the further research on dynamic walking stability of the quadruped robot in unstructured environment.
文摘Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR （aryl hydrocarbon receptor） pathway, tobacco-similar pathway, oxidation, as well as epigenetics pathway were reviewed. Based on the working mechanism, the reported study method and methodology used in Ashland lab were reviewed, including cell level experiment, through reconstructed human skin to in vivo study.
文摘In order to improve efficiency of coal seam gas drainage, many fracturing techniques, such as waterjet fracturing, hydraulic fracturing and explosive fracturing, etc, have been developed and widely used in China coal mining industry. How- ever, during the engineering applications, it is observed that the efficiency of gas drainage initially improves, but reduces there- after. Thus, it is speculated that the contrasts in coalbed methane drainage efficiency may reflect variation of the closure be- havior of the artificial fracture created. Based on comprehensive gas drainage monitoring data in underground coal mines, the work presented herein uses numerical simulation to show the behavior of the time-dependent closure of coal seam fractures as- sociated with various levels of waterjet fracturing parameters and geomechanical conditions.
文摘The general idea of this work is to improve the performance of CAES （compressed air energy storage） for its application in solar and wind systems through a restitution technique by creating an artificial wind. The efficiency of compressed air storage is often presented as a limit to its application. The present work describes a series of manipulations carried out in order to increase the yield. As the action of the artificial wind on the wind turbine is characterized by a reduced attack surface, a treated wind, a constant direction, an adjustable speed, it is therefore a question of acting on all the controllable parameters of the artificial wind to find the best way to use it to produce more energy from a certain quantity stored in a tank. The main manipulations consisted in determining： the optimal number of points of attack of the wind turbine; the nature of the action （continuous or interrupted） of the wind; the frequency of wind action and the duty cycle.
