Surface charge accumulation is considered to be a critical factor in flashover failure of three-post insulators.However,surface charge accumulation characteristics on threepost insulators with complex structures and u...Surface charge accumulation is considered to be a critical factor in flashover failure of three-post insulators.However,surface charge accumulation characteristics on threepost insulators with complex structures and uneven electric fields are still unclear.Furthermore,the temperature gradient field makes charge accumulation more complicated.In this presentation,surface charge profiles of DC three-post insulators under electro-thermal coupling stress are studied by establishing a multi-degree-of-freedom movement measurement system.The abdominal area of the three-post insulator accumulaftes charges of identical polarity as the DC voltage,while the leg area accumulates heteropolar charges.Charge density from the bottom of the leg to the center of the abdomen presents a trimodal distribution pattern,including two homopolar charge peaks and one heteropolar charge peak.Asymmetrical surface conductance distribution arising from the temperature gradient leads to a significant increase in amplitude and distribution range of the homopolar charge peak at the legs of insulator.Increase of the temperature gradient will further magnify the homopolar charge peak at the legs.When DC voltage is 100 kV and conductive pole temperature is 70℃,surface charge density of the three-post insulator can reach 100μC/m^(2).Therefore,surface conductance regulation of the leg region is the key to charge regulation and insulation optimization design of DC three-post insulators.展开更多
目的观察综合针刺治疗卒中后运动性失语(post-stroke motor aphasia,PSMA)的临床疗效及对血液学指标的影响。方法将74例PSMA患者以简单随机数字表法随机分为观察组和对照组,每组37例。两组均予以西医基础治疗,对照组另予普通针刺,观察...目的观察综合针刺治疗卒中后运动性失语(post-stroke motor aphasia,PSMA)的临床疗效及对血液学指标的影响。方法将74例PSMA患者以简单随机数字表法随机分为观察组和对照组,每组37例。两组均予以西医基础治疗,对照组另予普通针刺,观察组另予综合针刺。比较两组临床疗效和不良反应发生情况,观察两组治疗前后汉语失语症检查法(aphasia battery of Chinese,ABC)评分、波士顿诊断性失语症检查(Boston diagnostic aphasia examination,BDAE)分级、美国国立卫生研究院卒中量表(National Institutes of Health stroke scale,NIHSS)评分、简易智力状况检查量表(mini-mental state examination,MMSE)评分、血清降钙素基因相关肽(calcitonin gene-related peptide,CGRP)水平、血管内皮素(endothelin,ET)水平、神经烯醇化酶(neuron-specific enolase,NSE)水平、红细胞聚集指数、全血黏度及血沉方程K指数的变化。结果观察组总有效率高于对照组(P<0.05)。治疗后,两组ABC中听理解、自发言语和复述及命名的评分均升高(P<0.05),且观察组高于对照组(P<0.05)。治疗后,观察组BDAE分级较治疗前明显改善(P<0.05),且优于对照组(P<0.05)。治疗后,两组NIHSS评分均降低(P<0.05),且观察组低于对照组(P<0.05);两组MMSE评分均升高(P<0.05),且观察组高于对照组(P<0.05)。治疗后,两组血清CGRP水平均升高(P<0.05),且观察组高于对照组(P<0.05);ET及NSE水平均降低(P<0.05),且观察组低于对照组(P<0.05)。治疗后,两组全血黏度、红细胞聚集指数及血沉方程K指数均降低(P<0.05),且观察组均低于对照组(P<0.05)。两组未有不良反应发生。结论在西医基础治疗基础上,综合针刺可进一步改善PSMA患者语言功能、认知功能、血清学及血液流变学指标,改善失语症状,疗效优于普通针刺。展开更多
基金supported by the National Natural Science Foundation of China(51737005,52127812,51929701).
文摘Surface charge accumulation is considered to be a critical factor in flashover failure of three-post insulators.However,surface charge accumulation characteristics on threepost insulators with complex structures and uneven electric fields are still unclear.Furthermore,the temperature gradient field makes charge accumulation more complicated.In this presentation,surface charge profiles of DC three-post insulators under electro-thermal coupling stress are studied by establishing a multi-degree-of-freedom movement measurement system.The abdominal area of the three-post insulator accumulaftes charges of identical polarity as the DC voltage,while the leg area accumulates heteropolar charges.Charge density from the bottom of the leg to the center of the abdomen presents a trimodal distribution pattern,including two homopolar charge peaks and one heteropolar charge peak.Asymmetrical surface conductance distribution arising from the temperature gradient leads to a significant increase in amplitude and distribution range of the homopolar charge peak at the legs of insulator.Increase of the temperature gradient will further magnify the homopolar charge peak at the legs.When DC voltage is 100 kV and conductive pole temperature is 70℃,surface charge density of the three-post insulator can reach 100μC/m^(2).Therefore,surface conductance regulation of the leg region is the key to charge regulation and insulation optimization design of DC three-post insulators.
文摘目的观察综合针刺治疗卒中后运动性失语(post-stroke motor aphasia,PSMA)的临床疗效及对血液学指标的影响。方法将74例PSMA患者以简单随机数字表法随机分为观察组和对照组,每组37例。两组均予以西医基础治疗,对照组另予普通针刺,观察组另予综合针刺。比较两组临床疗效和不良反应发生情况,观察两组治疗前后汉语失语症检查法(aphasia battery of Chinese,ABC)评分、波士顿诊断性失语症检查(Boston diagnostic aphasia examination,BDAE)分级、美国国立卫生研究院卒中量表(National Institutes of Health stroke scale,NIHSS)评分、简易智力状况检查量表(mini-mental state examination,MMSE)评分、血清降钙素基因相关肽(calcitonin gene-related peptide,CGRP)水平、血管内皮素(endothelin,ET)水平、神经烯醇化酶(neuron-specific enolase,NSE)水平、红细胞聚集指数、全血黏度及血沉方程K指数的变化。结果观察组总有效率高于对照组(P<0.05)。治疗后,两组ABC中听理解、自发言语和复述及命名的评分均升高(P<0.05),且观察组高于对照组(P<0.05)。治疗后,观察组BDAE分级较治疗前明显改善(P<0.05),且优于对照组(P<0.05)。治疗后,两组NIHSS评分均降低(P<0.05),且观察组低于对照组(P<0.05);两组MMSE评分均升高(P<0.05),且观察组高于对照组(P<0.05)。治疗后,两组血清CGRP水平均升高(P<0.05),且观察组高于对照组(P<0.05);ET及NSE水平均降低(P<0.05),且观察组低于对照组(P<0.05)。治疗后,两组全血黏度、红细胞聚集指数及血沉方程K指数均降低(P<0.05),且观察组均低于对照组(P<0.05)。两组未有不良反应发生。结论在西医基础治疗基础上,综合针刺可进一步改善PSMA患者语言功能、认知功能、血清学及血液流变学指标,改善失语症状,疗效优于普通针刺。
