A new soluble subphthalocyanine was first prepared and its fluorescence property was investigated. It exhibited both S-1 and S-2 emissions, of which the quantum yields and the lifetimes were measured.
The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customa...The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customarily applied before.In addition,the spectra of mono-energetic alpha particles show a well known asymmetric shape as well when measured by silicon detectors.This article presents a physical model predicting the observed energy spectrum of a sample ion with target nuclides in prearranged depths.It is expressed as the convolution of a Gaussian function with a left-hand double-exponential function.Experiment showed that the predicted ions spectrum derived from the asymmetric model matches the observed energy spectrum.Therefore,the model can be applied to produce matrix for inversion of NDP spectrum.展开更多
针对目前采用单一步长跟踪的最大功率跟踪(maximum power point tracking,MPPT)控制策略中,存在步长选取的差异无法兼得系统动态性能和稳态精度的问题,提出了恒压启动法与双指数函数步长算法结合的改进的MPPT控制策略。在启动时采用恒...针对目前采用单一步长跟踪的最大功率跟踪(maximum power point tracking,MPPT)控制策略中,存在步长选取的差异无法兼得系统动态性能和稳态精度的问题,提出了恒压启动法与双指数函数步长算法结合的改进的MPPT控制策略。在启动时采用恒定电压法快速定位在最大功率点(maximum power point,MPP)附近,然后利用双指数函数改变步长并精确跟踪光伏最大功率点,利用两种指数函数的函数特性实时调整MPP两侧的步长叠加量,进一步优化变步长跟踪效果。最后在MATLAB/Simulink平台中进行对比分析。结果表明:所提出的算法对提高光伏MPPT的快速性和减小稳态波动是有效的。展开更多
文摘A new soluble subphthalocyanine was first prepared and its fluorescence property was investigated. It exhibited both S-1 and S-2 emissions, of which the quantum yields and the lifetimes were measured.
文摘The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customarily applied before.In addition,the spectra of mono-energetic alpha particles show a well known asymmetric shape as well when measured by silicon detectors.This article presents a physical model predicting the observed energy spectrum of a sample ion with target nuclides in prearranged depths.It is expressed as the convolution of a Gaussian function with a left-hand double-exponential function.Experiment showed that the predicted ions spectrum derived from the asymmetric model matches the observed energy spectrum.Therefore,the model can be applied to produce matrix for inversion of NDP spectrum.
文摘针对目前采用单一步长跟踪的最大功率跟踪(maximum power point tracking,MPPT)控制策略中,存在步长选取的差异无法兼得系统动态性能和稳态精度的问题,提出了恒压启动法与双指数函数步长算法结合的改进的MPPT控制策略。在启动时采用恒定电压法快速定位在最大功率点(maximum power point,MPP)附近,然后利用双指数函数改变步长并精确跟踪光伏最大功率点,利用两种指数函数的函数特性实时调整MPP两侧的步长叠加量,进一步优化变步长跟踪效果。最后在MATLAB/Simulink平台中进行对比分析。结果表明:所提出的算法对提高光伏MPPT的快速性和减小稳态波动是有效的。
