The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with ...The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with the CMOS circuit,but also acts on the protection circuit.This paper establishes a model of on-chip CMOS electrostatic discharge protection circuit and selects square pulse as the FREMP signals.Based on multiple physical parameter models,it depicts the distribution of the lattice temperature,current density,and electric field intensity inside the device.At the same time,this paper explores the changes of the internal devices in the circuit under the injection of fast rising time electromagnetic pulse and describes the relationship between the damage amplitude threshold and the pulse width.The results show that the ESD protection circuit has potential damage risk,and the injection of FREMP leads to irreversible heat loss inside the circuit.In addition,pulse signals with different attributes will change the damage threshold of the circuit.These results provide an important reference for further evaluation of the influence of electromagnetic environment on the chip,which is helpful to carry out the reliability enhancement research of ESD protection circuit.展开更多
非点源污染是导致流域水体水质恶化的关键污染来源之一,为了估算流域非点源污染负荷,本文提出将一维水质模型应用于分离监测断面点源污染负荷和非点源污染负荷的方法,并结合了改进的输出系数法,以CODMn和NH3-N为代表性指标,将该模型应...非点源污染是导致流域水体水质恶化的关键污染来源之一,为了估算流域非点源污染负荷,本文提出将一维水质模型应用于分离监测断面点源污染负荷和非点源污染负荷的方法,并结合了改进的输出系数法,以CODMn和NH3-N为代表性指标,将该模型应用于潮河下游流域,并与传统的水文分割法结合改进的输出系数法估算非点源污染负荷的结果进行对比。结果表明,一维水质模型结合改进的输出系数法估算流域非点源CODMn和NH3-N污染负荷模拟值的纳什系数均在0.800以上,具有良好的模拟精度,同时避免了水文分割法无法较好地模拟枯水期非点源污染负荷的弊端。该方法在运用SWAT (soil and water assessment tool)模型预测得到水文数据的情况下,能够预测流域非点源污染负荷,作为SWAT模型对COD模拟的补充。展开更多
目的探讨关节腔注射交联几丁糖治疗兔膝骨关节炎的效果。方法将32只新西兰白兔随机分为A、B、C、D 4组(n=8),其中A、B、C组采用切断左后肢前交叉韧带方法制备膝骨关节炎模型;4周后,A组关节腔内注射交联几丁糖0.6 mL 1次;B、C组分别注射...目的探讨关节腔注射交联几丁糖治疗兔膝骨关节炎的效果。方法将32只新西兰白兔随机分为A、B、C、D 4组(n=8),其中A、B、C组采用切断左后肢前交叉韧带方法制备膝骨关节炎模型;4周后,A组关节腔内注射交联几丁糖0.6 mL 1次;B、C组分别注射几丁糖、生理盐水,0.3 mL/次,每2周1次;D组为假手术组,关节腔内注射等量生理盐水。造模术后8周,行软骨大体观察、扫描电镜观察、组织学观测(HE染色、番红-固绿染色以及Mankin评分)、Ⅱ型胶原免疫组织化学染色观测。结果大体及扫描电镜观察示D组软骨结构接近正常,A、B组软骨表面结构磨损较D组严重,C组最严重;组织学染色观察示,A、B组软骨结构相似,且优于C组,但尚未达D组正常结构。B、C组软骨大体评分及Mankin评分明显高于D组(P<0.05),A、B组比较差异无统计学意义(P>0.05)。免疫组织化学染色观察示D组Ⅱ型胶原阳性软骨细胞百分比明显高于B、C组(P<0.05),A、B组比较差异无统计学意义(P>0.05)。结论交联几丁糖能明显改善兔膝骨关节炎,延缓骨关节炎病理改变,且注射次数减少。展开更多
基金National Natural Science Foundation of China(61974116)。
文摘The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with the CMOS circuit,but also acts on the protection circuit.This paper establishes a model of on-chip CMOS electrostatic discharge protection circuit and selects square pulse as the FREMP signals.Based on multiple physical parameter models,it depicts the distribution of the lattice temperature,current density,and electric field intensity inside the device.At the same time,this paper explores the changes of the internal devices in the circuit under the injection of fast rising time electromagnetic pulse and describes the relationship between the damage amplitude threshold and the pulse width.The results show that the ESD protection circuit has potential damage risk,and the injection of FREMP leads to irreversible heat loss inside the circuit.In addition,pulse signals with different attributes will change the damage threshold of the circuit.These results provide an important reference for further evaluation of the influence of electromagnetic environment on the chip,which is helpful to carry out the reliability enhancement research of ESD protection circuit.
文摘非点源污染是导致流域水体水质恶化的关键污染来源之一,为了估算流域非点源污染负荷,本文提出将一维水质模型应用于分离监测断面点源污染负荷和非点源污染负荷的方法,并结合了改进的输出系数法,以CODMn和NH3-N为代表性指标,将该模型应用于潮河下游流域,并与传统的水文分割法结合改进的输出系数法估算非点源污染负荷的结果进行对比。结果表明,一维水质模型结合改进的输出系数法估算流域非点源CODMn和NH3-N污染负荷模拟值的纳什系数均在0.800以上,具有良好的模拟精度,同时避免了水文分割法无法较好地模拟枯水期非点源污染负荷的弊端。该方法在运用SWAT (soil and water assessment tool)模型预测得到水文数据的情况下,能够预测流域非点源污染负荷,作为SWAT模型对COD模拟的补充。
文摘目的探讨关节腔注射交联几丁糖治疗兔膝骨关节炎的效果。方法将32只新西兰白兔随机分为A、B、C、D 4组(n=8),其中A、B、C组采用切断左后肢前交叉韧带方法制备膝骨关节炎模型;4周后,A组关节腔内注射交联几丁糖0.6 mL 1次;B、C组分别注射几丁糖、生理盐水,0.3 mL/次,每2周1次;D组为假手术组,关节腔内注射等量生理盐水。造模术后8周,行软骨大体观察、扫描电镜观察、组织学观测(HE染色、番红-固绿染色以及Mankin评分)、Ⅱ型胶原免疫组织化学染色观测。结果大体及扫描电镜观察示D组软骨结构接近正常,A、B组软骨表面结构磨损较D组严重,C组最严重;组织学染色观察示,A、B组软骨结构相似,且优于C组,但尚未达D组正常结构。B、C组软骨大体评分及Mankin评分明显高于D组(P<0.05),A、B组比较差异无统计学意义(P>0.05)。免疫组织化学染色观察示D组Ⅱ型胶原阳性软骨细胞百分比明显高于B、C组(P<0.05),A、B组比较差异无统计学意义(P>0.05)。结论交联几丁糖能明显改善兔膝骨关节炎,延缓骨关节炎病理改变,且注射次数减少。
