为计算腐蚀海底管道的剩余强度,分析海底管道的在位强度计算方法,提出一种海底管道校核方法。将腐蚀管道的强度校核分为整体强度和局部强度分析,通过ECE5模拟预测海底管道均匀腐蚀深度和局部腐蚀深度,利用原设计规范(DNV OS F101或DNV19...为计算腐蚀海底管道的剩余强度,分析海底管道的在位强度计算方法,提出一种海底管道校核方法。将腐蚀管道的强度校核分为整体强度和局部强度分析,通过ECE5模拟预测海底管道均匀腐蚀深度和局部腐蚀深度,利用原设计规范(DNV OS F101或DNV1981)计算海底管道的整体强度,采用DNV-RP-F101计算海底管道腐蚀点的局部强度,采用有限元方法对腐蚀点的局部强度进行模拟计算,为腐蚀管道的安全性评估提供依据。展开更多
目的分析同种异体脂肪干细胞(ADSC)移植促进慢性创面修复的效果及Ras同源基因家族成员A(RhoA)-Yes相关蛋白(YAP)信号通路活化的机制。方法选择2个月龄SD大鼠31只,雌雄不限,体质量112~120 g,平均体质量116.7 g。以其中1只提取ADSC并鉴定...目的分析同种异体脂肪干细胞(ADSC)移植促进慢性创面修复的效果及Ras同源基因家族成员A(RhoA)-Yes相关蛋白(YAP)信号通路活化的机制。方法选择2个月龄SD大鼠31只,雌雄不限,体质量112~120 g,平均体质量116.7 g。以其中1只提取ADSC并鉴定;30只大鼠随机分为5组:模型组(自身皮瓣移植),ADSC移植组,RhoA抑制剂C3干预组(简称C3干预组),慢病毒转染沉默YAP表达组(简称shYAP组),C3和慢病毒转染联合干预组(简称联合组)。分别在移植后7 d和21 d采用激光多普勒血流计测定创面血流量、皮瓣成活率,逆转录聚合酶链反应(RT-PCR)和Western blot法检测创面RhoA、YAP、结缔组织生长因子(CTGF)和血管内皮生长因子(VEGF)mRNA和蛋白的定量表达水平。结果体外成功分离并鉴定为ADSC。30只大鼠均成活至实验21 d。ADSC移植组7 d和21 d皮肤血流量[7 d(256.3±56.2) PU,21 d (421.5±82.8) PU]、皮瓣成活率[7 d (32.6±10.6)%,21 d (45.8±17.5)%]、RhoA mRNA(7 d0.36±0.07,21 d 0.58±0.12)、YAP mRNA(7 d 0.33±0.06,21 d 0.52±0.13)、CTGF mRNA(7 d 0.49±0.11,21 d 0.67±0.15)和VEGF mRNA(7 d 0.48±0.14,21 d 0.68±0.16)及蛋白定量表达水平(7 d 0.37±0.07,21 d 0.59±0.12;7 d 0.35±0.06,21 d 0.54±0.13;7 d 0.46±0.11,21 d 0.65±0.15;7 d 0.47±0.14,21 d 0.67±0.16)均显著高于其他各组,联合组显著低于C3干预组和shYAP组,差异有统计学意义(P <0.05)。结论同种异体ADSC可提高慢性创面移植皮瓣的存活率,促进创面愈合,增加创面组织CTGF和VEGF表达,可能通过介导RhoA-YAP信号通路的活化程度来实现。展开更多
Islanding detection is a mandatory component in grid-connected photovoltaic （PV） inverters. It is also a key issue in the photovoltaic agriculture. In this work, an overview on the islanding effect in grid-connected...Islanding detection is a mandatory component in grid-connected photovoltaic （PV） inverters. It is also a key issue in the photovoltaic agriculture. In this work, an overview on the islanding effect in grid-connected PV power systems was provided. Various islanding detection methods were introduced and their strength and weakness were dicussed. An improved islanding detection method was proposed based on active frequency drift （AFD）. The new method tolerated capacitive and inductive loads, because its perturbation signal was not offset by the non-resistive load. The new method through simulation in MATLAB/Simulink was evaluated and the advantages of the new method were demonstrated.展开更多
文摘为计算腐蚀海底管道的剩余强度,分析海底管道的在位强度计算方法,提出一种海底管道校核方法。将腐蚀管道的强度校核分为整体强度和局部强度分析,通过ECE5模拟预测海底管道均匀腐蚀深度和局部腐蚀深度,利用原设计规范(DNV OS F101或DNV1981)计算海底管道的整体强度,采用DNV-RP-F101计算海底管道腐蚀点的局部强度,采用有限元方法对腐蚀点的局部强度进行模拟计算,为腐蚀管道的安全性评估提供依据。
文摘目的分析同种异体脂肪干细胞(ADSC)移植促进慢性创面修复的效果及Ras同源基因家族成员A(RhoA)-Yes相关蛋白(YAP)信号通路活化的机制。方法选择2个月龄SD大鼠31只,雌雄不限,体质量112~120 g,平均体质量116.7 g。以其中1只提取ADSC并鉴定;30只大鼠随机分为5组:模型组(自身皮瓣移植),ADSC移植组,RhoA抑制剂C3干预组(简称C3干预组),慢病毒转染沉默YAP表达组(简称shYAP组),C3和慢病毒转染联合干预组(简称联合组)。分别在移植后7 d和21 d采用激光多普勒血流计测定创面血流量、皮瓣成活率,逆转录聚合酶链反应(RT-PCR)和Western blot法检测创面RhoA、YAP、结缔组织生长因子(CTGF)和血管内皮生长因子(VEGF)mRNA和蛋白的定量表达水平。结果体外成功分离并鉴定为ADSC。30只大鼠均成活至实验21 d。ADSC移植组7 d和21 d皮肤血流量[7 d(256.3±56.2) PU,21 d (421.5±82.8) PU]、皮瓣成活率[7 d (32.6±10.6)%,21 d (45.8±17.5)%]、RhoA mRNA(7 d0.36±0.07,21 d 0.58±0.12)、YAP mRNA(7 d 0.33±0.06,21 d 0.52±0.13)、CTGF mRNA(7 d 0.49±0.11,21 d 0.67±0.15)和VEGF mRNA(7 d 0.48±0.14,21 d 0.68±0.16)及蛋白定量表达水平(7 d 0.37±0.07,21 d 0.59±0.12;7 d 0.35±0.06,21 d 0.54±0.13;7 d 0.46±0.11,21 d 0.65±0.15;7 d 0.47±0.14,21 d 0.67±0.16)均显著高于其他各组,联合组显著低于C3干预组和shYAP组,差异有统计学意义(P <0.05)。结论同种异体ADSC可提高慢性创面移植皮瓣的存活率,促进创面愈合,增加创面组织CTGF和VEGF表达,可能通过介导RhoA-YAP信号通路的活化程度来实现。
基金Supported by the National Science and Technology Support Program(2014BAD06B04-1-09)China Postdoctoral Fund(2016M601406)Heilongjiang Postdoctoral Fund(LBHZ15024)
文摘Islanding detection is a mandatory component in grid-connected photovoltaic （PV） inverters. It is also a key issue in the photovoltaic agriculture. In this work, an overview on the islanding effect in grid-connected PV power systems was provided. Various islanding detection methods were introduced and their strength and weakness were dicussed. An improved islanding detection method was proposed based on active frequency drift （AFD）. The new method tolerated capacitive and inductive loads, because its perturbation signal was not offset by the non-resistive load. The new method through simulation in MATLAB/Simulink was evaluated and the advantages of the new method were demonstrated.
