To investigate the influence of microwave heating on the dynamic behavior and failure mechanisms of rock,dynamic compression tests were conducted on microwave-irradiated sandstone specimens using a modified split Hopk...To investigate the influence of microwave heating on the dynamic behavior and failure mechanisms of rock,dynamic compression tests were conducted on microwave-irradiated sandstone specimens using a modified split Hopkinson pressure bar(SHPB)system.Experimental results show that microwave radiation can effectively weaken the compressive strength of sandstone.Rock specimens show three different failure modes under impact load:tensile failure,tensile−shear composite failure and compressive−shear failure.The dynamic Poisson’s ratio,calculated using the measured P-and S-wave velocities,is introduced to describe the deformation characteristics of sandstone.With the increase in microwave power and heating time,the Poisson’s ratio declines first and then increases slightly,and the turning point occurs at 244.6℃.Moreover,the microstructural characteristics reveal that microwave radiation produces dehydration,pore expansion,and cracking of the rock.The damage mechanisms caused by microwave radiation are discussed based on thermal stress and steam pressure inside the rock,which provides a reasonable explanation for the experimental results.展开更多
Objective:In traditional herbal medicine(Kampo medicine in Japan),'sho'is diagnosed by the traditional assessments of clinical conditions.Among a variety of the shos,there is an'oketsu'syndrome,which i...Objective:In traditional herbal medicine(Kampo medicine in Japan),'sho'is diagnosed by the traditional assessments of clinical conditions.Among a variety of the shos,there is an'oketsu'syndrome,which is a stagnation and disturbance of microcirculation.The prompt effects of four anti-oketsu formulations in Kampo medicine on cardiovascular functions were compared in oketsu and non-oketsu persons.Methods:The arterial pulse wave from radial artery is formed by the combination with ejection and reflection pulses.An augmentation index(AI),a ration of the ejection and reflection pulses,indicates a degree of arteriosclerosis.For both seventy-six students with oketsu and thirty-seven students with non-oketsu,Kampo formulations overcoming oketsu of Tokishakuyakusan(TS,Dang-Gui-Shao-Yao-San),Kamishoyosan(KS,Jia-Wei-Xiao-Yao-San),Keisibukuryogan(KB,Gui-Zhi-Fu-Ling-Wan)and Tokakujokito(TJ,Tao-He-Cheng-Qi-Tang)were taken once,and then,the cardiovascular functions including blood pressure,heart rate,central arterial blood pressure(CBP)and AI were examined for 60 min.Results:At 40-60 min after an intake,these formulations decreased the AI almost by 6-18%(n=76),by 18.3±3.1%(P<0.01,n=15)with TJ.Simultaneously,the CBP was reduced by 9.0±1.8%(P<0.05,n=23)with KS and by 9.1±2.0%(P<0.05,n=15)with TJ.On the other hands,non-oketsu group had less or no effect by any kinds of the formulations.Conclusion:The anti-oketsu formulations can exert the ameliorative action for oketsu persons via decreasing AI and CBP.展开更多
基金the National Natural Science Foundation of China(Nos.41972283,11972378)the National Key Scientific Instrument and Equipment Development,China(No.51927808)the Hunan Provincial Innovation Foundation for Postgraduate,China(No.CX2018B066).
文摘To investigate the influence of microwave heating on the dynamic behavior and failure mechanisms of rock,dynamic compression tests were conducted on microwave-irradiated sandstone specimens using a modified split Hopkinson pressure bar(SHPB)system.Experimental results show that microwave radiation can effectively weaken the compressive strength of sandstone.Rock specimens show three different failure modes under impact load:tensile failure,tensile−shear composite failure and compressive−shear failure.The dynamic Poisson’s ratio,calculated using the measured P-and S-wave velocities,is introduced to describe the deformation characteristics of sandstone.With the increase in microwave power and heating time,the Poisson’s ratio declines first and then increases slightly,and the turning point occurs at 244.6℃.Moreover,the microstructural characteristics reveal that microwave radiation produces dehydration,pore expansion,and cracking of the rock.The damage mechanisms caused by microwave radiation are discussed based on thermal stress and steam pressure inside the rock,which provides a reasonable explanation for the experimental results.
文摘Objective:In traditional herbal medicine(Kampo medicine in Japan),'sho'is diagnosed by the traditional assessments of clinical conditions.Among a variety of the shos,there is an'oketsu'syndrome,which is a stagnation and disturbance of microcirculation.The prompt effects of four anti-oketsu formulations in Kampo medicine on cardiovascular functions were compared in oketsu and non-oketsu persons.Methods:The arterial pulse wave from radial artery is formed by the combination with ejection and reflection pulses.An augmentation index(AI),a ration of the ejection and reflection pulses,indicates a degree of arteriosclerosis.For both seventy-six students with oketsu and thirty-seven students with non-oketsu,Kampo formulations overcoming oketsu of Tokishakuyakusan(TS,Dang-Gui-Shao-Yao-San),Kamishoyosan(KS,Jia-Wei-Xiao-Yao-San),Keisibukuryogan(KB,Gui-Zhi-Fu-Ling-Wan)and Tokakujokito(TJ,Tao-He-Cheng-Qi-Tang)were taken once,and then,the cardiovascular functions including blood pressure,heart rate,central arterial blood pressure(CBP)and AI were examined for 60 min.Results:At 40-60 min after an intake,these formulations decreased the AI almost by 6-18%(n=76),by 18.3±3.1%(P<0.01,n=15)with TJ.Simultaneously,the CBP was reduced by 9.0±1.8%(P<0.05,n=23)with KS and by 9.1±2.0%(P<0.05,n=15)with TJ.On the other hands,non-oketsu group had less or no effect by any kinds of the formulations.Conclusion:The anti-oketsu formulations can exert the ameliorative action for oketsu persons via decreasing AI and CBP.
