Impact of air pollution on cardiovascular d is eases has been established. As the main source of city air pollution, particulat e matter has been demonstrated an independent correlation with incidence and mor tality o...Impact of air pollution on cardiovascular d is eases has been established. As the main source of city air pollution, particulat e matter has been demonstrated an independent correlation with incidence and mor tality of cardiovascular diseases. The mechanisms are not clear. Several plausib le mechanistic pathways have been described, including inflammation induced by o xidative stress, the followed enhanced coagulation/thrombosis resulted in instab ility of atherosclerosis, the promotion of ischemic heart diseases and imbalance of autonomic nerve tone resulted in the occurrence of arrhythmia. The article p rovides a review of the mechanisms on air pollution and cardiovascular diseases and suggestions for further research.展开更多
文摘虚拟同步机VSG(virtual synchronous generator)通过模拟同步机特性为新能源并网提供惯性和阻尼。然而,电力电子开关器件高频开关过程中可能会发生断路故障,导致输出电流波形严重畸变,影响电网安全稳定运行。针对中点箝位型NPC(neutral point clamped)三电平VSG桥臂故障问题,提出一种中点电压均衡的VSG容错模型预测控制策略。分析NPC三电平VSG单相桥臂故障后运行机理,在开关器件故障后利用直流侧电容组成虚拟桥臂,重构为VSG桥臂故障容错结构。建立故障情况下预测电流模型,重构故障状态空间电压矢量,将直流侧中点电容电压引入容错模型代价函数,减小电容电压波动,实现VSG桥臂故障容错运行。实验结果表明,在开关器件发生故障后,NPC三电平VSG能容错连续运行,验证了所提模型预测容错控制策略的有效性,提高了VSG运行可靠性。
文摘Impact of air pollution on cardiovascular d is eases has been established. As the main source of city air pollution, particulat e matter has been demonstrated an independent correlation with incidence and mor tality of cardiovascular diseases. The mechanisms are not clear. Several plausib le mechanistic pathways have been described, including inflammation induced by o xidative stress, the followed enhanced coagulation/thrombosis resulted in instab ility of atherosclerosis, the promotion of ischemic heart diseases and imbalance of autonomic nerve tone resulted in the occurrence of arrhythmia. The article p rovides a review of the mechanisms on air pollution and cardiovascular diseases and suggestions for further research.
