The ＂double low-points＂ anomaly in daily variation of vertical geomagnetic component was observed on May 9, 2008 at 13 geomagnetic observatories belonging to the geomagnetic observatory network center of China Earth...The ＂double low-points＂ anomaly in daily variation of vertical geomagnetic component was observed on May 9, 2008 at 13 geomagnetic observatories belonging to the geomagnetic observatory network center of China Earthquake Administration. These observatories distribute roughly on three belts with the intersection in western Sichuan. On May 12, three days after the anomaly appearance, the great Ms8.0 Wenchuan earthquake occurred. The ＂double low-points＂ anomaly in daily variation of vertical geomagnetic component is an anomalous phenomenon of regional geomagnetism, which does exist objectively. The possible cause is the change of extrinsic eddy current system resulting in geomagnetic daily quiet variation （Sq）, or the delay of several hours between the intrinsic and the extrinsic eddy current systems. The relationship between the ＂double low-points＂ anomaly of daily geomagnetic variation and the earthquake reveals that the former possibly reflects the accelerative alteration of earthquake gestation in the deep Earth.展开更多
为了契合绿色可再生能源发展理念,自供电环境能量收集系统已逐渐成为替代传统电池的高效解决方案,可克服传统电池在重量、尺寸及循环寿命等方面的局限性。针对压电源的时变特性,设计了一种基于其特性的快速最大功率点跟踪(Maximum Power...为了契合绿色可再生能源发展理念,自供电环境能量收集系统已逐渐成为替代传统电池的高效解决方案,可克服传统电池在重量、尺寸及循环寿命等方面的局限性。针对压电源的时变特性,设计了一种基于其特性的快速最大功率点跟踪(Maximum Power Point Tracking,MPPT)电路架构。对压电源的阻抗特性进行分析,采用了基于快速开关电容采样的开路电压采样MPPT算法,有效实现跟踪精度和动态响应速度的协同优化。最后,基于0.18μm BCD工艺对电路进行设计,仿真结果表明:MPPT的跟踪时间为0.36 ms,最大追踪精度可达99.4%。展开更多
文摘The ＂double low-points＂ anomaly in daily variation of vertical geomagnetic component was observed on May 9, 2008 at 13 geomagnetic observatories belonging to the geomagnetic observatory network center of China Earthquake Administration. These observatories distribute roughly on three belts with the intersection in western Sichuan. On May 12, three days after the anomaly appearance, the great Ms8.0 Wenchuan earthquake occurred. The ＂double low-points＂ anomaly in daily variation of vertical geomagnetic component is an anomalous phenomenon of regional geomagnetism, which does exist objectively. The possible cause is the change of extrinsic eddy current system resulting in geomagnetic daily quiet variation （Sq）, or the delay of several hours between the intrinsic and the extrinsic eddy current systems. The relationship between the ＂double low-points＂ anomaly of daily geomagnetic variation and the earthquake reveals that the former possibly reflects the accelerative alteration of earthquake gestation in the deep Earth.
文摘为了契合绿色可再生能源发展理念,自供电环境能量收集系统已逐渐成为替代传统电池的高效解决方案,可克服传统电池在重量、尺寸及循环寿命等方面的局限性。针对压电源的时变特性,设计了一种基于其特性的快速最大功率点跟踪(Maximum Power Point Tracking,MPPT)电路架构。对压电源的阻抗特性进行分析,采用了基于快速开关电容采样的开路电压采样MPPT算法,有效实现跟踪精度和动态响应速度的协同优化。最后,基于0.18μm BCD工艺对电路进行设计,仿真结果表明:MPPT的跟踪时间为0.36 ms,最大追踪精度可达99.4%。
