Based on the MTLL lightning return stroke model,a two-dimensional cylindrical finite-difference time-domain( FDTD) model for underground horizontal electric field was established,and the effects of distance from light...Based on the MTLL lightning return stroke model,a two-dimensional cylindrical finite-difference time-domain( FDTD) model for underground horizontal electric field was established,and the effects of distance from lightning channel,depth,soil electrical conductivity and its distribution,and return stroke current on the characteristics of underground horizontal electric field were analyzed. The results showed that as long as the electrical conductivity of soil existed,the peak of underground horizontal electric field decreased with the increase in the horizontal distance from lightning channel. When the electrical conductivity of the upper soil was much smaller than that of the lower soil,the peak of corresponding horizontal electric field was larger than the electric field peak as the electrical conductivity of the upper soil was larger than that of the lower soil. When the electrical conductivity of the upper soil was less than that of the lower soil,the growth and decay of the horizontal electric field were faster than the growth and decay as the electrical conductivity of the upper soil was larger than that of the lower soil.展开更多
Electric and magnetic fields in time and frequency domain due to return stroke-lateral corona (RS-LC) system and re- cently discovered red sprites have been calculated. It has been found that the electric and magnetic...Electric and magnetic fields in time and frequency domain due to return stroke-lateral corona (RS-LC) system and re- cently discovered red sprites have been calculated. It has been found that the electric and magnetic fields due to return stroke and lateral corona system radiate in the very low frequency (VLF) region while due to sprites radiate in the ex- tremely low frequency (ELF) range. A comparison has been made between the radiations emitted due to RS-LC system and sprites in ELF (0 - 200 Hz) region. It has been found that the electric field i.e. radiation power generated due to sprites dominates in the ELF range and thus it is concluded that the red sprites as compared to the RS-LC system are the prominent source for the excitation of Schumann resonances in the earth-ionosphere waveguide.展开更多
目的:观察针药结合对急性期缺血性脑卒中患者神经功能的保护作用。方法:选取2019年3月至2021年3月东台市中医院急诊收住入院治疗的急性期缺血性脑卒中气虚血瘀证患者90例,按照随机数字表法分为观察组和对照组,每组45例。两组患者均给予...目的:观察针药结合对急性期缺血性脑卒中患者神经功能的保护作用。方法:选取2019年3月至2021年3月东台市中医院急诊收住入院治疗的急性期缺血性脑卒中气虚血瘀证患者90例,按照随机数字表法分为观察组和对照组,每组45例。两组患者均给予神经内科常规治疗,在病情允许的情况下,让患者行坐位保持,并进行坐位平衡训练,嘱咐患者多活动肩、肘、腕关节,并根据患者能忍受最大限度,进行旋、展、收等运动。对照组另给予补阳还五汤治疗,观察组在对照组治疗的基础上加用针刺疗法治疗。观察两组患者临床疗效及治疗前后神经功能缺损评分(national institute of health stroke scale,NIHSS)、Barthel指数、脑卒中专用生活质量量表(stroke specific quality of life,SS-QOL)、脑灌注指标[大脑后动脉(posterior cerebral artery,PCA)、大脑前动脉(arteriae cerebri anterior,ACA)、大脑中动脉(middle cerebral artery,MCA)的平均血流速度]、脑血流动力学指标[平均血流速度(mean velocity,Vm)、血管阻力指数(resistance index,RI)、搏动指数(pulsatility Index,PI)]变化情况。结果:观察组有效率95.56%,对照组有效率77.78%,观察组有效率高于对照组,差异有统计学意义(P<0.05);观察组治疗后Barthel指数、SS-QOL评分、PCA、ACA、MCA、Vm指标高于对照组,NIHSS评分、PI指标低于对照组,差异有统计学意义(P<0.05),观察组治疗后RI低于对照组,但差异无统计学意义(P>0.05)。结论:针药结合对急性期缺血性脑卒中气虚血瘀证患者神经功能有积极保护作用,提高患者NIHSS评分、Barthel指数,改善患者生活质量、脑组织再灌注指标、脑部血流动力学指标。展开更多
文摘Based on the MTLL lightning return stroke model,a two-dimensional cylindrical finite-difference time-domain( FDTD) model for underground horizontal electric field was established,and the effects of distance from lightning channel,depth,soil electrical conductivity and its distribution,and return stroke current on the characteristics of underground horizontal electric field were analyzed. The results showed that as long as the electrical conductivity of soil existed,the peak of underground horizontal electric field decreased with the increase in the horizontal distance from lightning channel. When the electrical conductivity of the upper soil was much smaller than that of the lower soil,the peak of corresponding horizontal electric field was larger than the electric field peak as the electrical conductivity of the upper soil was larger than that of the lower soil. When the electrical conductivity of the upper soil was less than that of the lower soil,the growth and decay of the horizontal electric field were faster than the growth and decay as the electrical conductivity of the upper soil was larger than that of the lower soil.
文摘Electric and magnetic fields in time and frequency domain due to return stroke-lateral corona (RS-LC) system and re- cently discovered red sprites have been calculated. It has been found that the electric and magnetic fields due to return stroke and lateral corona system radiate in the very low frequency (VLF) region while due to sprites radiate in the ex- tremely low frequency (ELF) range. A comparison has been made between the radiations emitted due to RS-LC system and sprites in ELF (0 - 200 Hz) region. It has been found that the electric field i.e. radiation power generated due to sprites dominates in the ELF range and thus it is concluded that the red sprites as compared to the RS-LC system are the prominent source for the excitation of Schumann resonances in the earth-ionosphere waveguide.
文摘目的:观察针药结合对急性期缺血性脑卒中患者神经功能的保护作用。方法:选取2019年3月至2021年3月东台市中医院急诊收住入院治疗的急性期缺血性脑卒中气虚血瘀证患者90例,按照随机数字表法分为观察组和对照组,每组45例。两组患者均给予神经内科常规治疗,在病情允许的情况下,让患者行坐位保持,并进行坐位平衡训练,嘱咐患者多活动肩、肘、腕关节,并根据患者能忍受最大限度,进行旋、展、收等运动。对照组另给予补阳还五汤治疗,观察组在对照组治疗的基础上加用针刺疗法治疗。观察两组患者临床疗效及治疗前后神经功能缺损评分(national institute of health stroke scale,NIHSS)、Barthel指数、脑卒中专用生活质量量表(stroke specific quality of life,SS-QOL)、脑灌注指标[大脑后动脉(posterior cerebral artery,PCA)、大脑前动脉(arteriae cerebri anterior,ACA)、大脑中动脉(middle cerebral artery,MCA)的平均血流速度]、脑血流动力学指标[平均血流速度(mean velocity,Vm)、血管阻力指数(resistance index,RI)、搏动指数(pulsatility Index,PI)]变化情况。结果:观察组有效率95.56%,对照组有效率77.78%,观察组有效率高于对照组,差异有统计学意义(P<0.05);观察组治疗后Barthel指数、SS-QOL评分、PCA、ACA、MCA、Vm指标高于对照组,NIHSS评分、PI指标低于对照组,差异有统计学意义(P<0.05),观察组治疗后RI低于对照组,但差异无统计学意义(P>0.05)。结论:针药结合对急性期缺血性脑卒中气虚血瘀证患者神经功能有积极保护作用,提高患者NIHSS评分、Barthel指数,改善患者生活质量、脑组织再灌注指标、脑部血流动力学指标。
