High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adapt...High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adaptability for high dynamics require either complicated structures or prior statistical information of noises.This paper proposes a high dynamics algorithm based on steepest ascent method that can circumvent the deficiencies of existing methods.First,the relationship between the error of carrier tracking and the maximum of Fast Fourier Transform(FFT)outputs is established,and a performance function based on the steepest ascent method is designed.It can keep stable in high dynamics.Second,a new carrier-tracking loop is constructed by deploying the performance function.When the variation of GPS receiver acceleration ranges from 10 g to 100 g,compared with the PLL that either loses lock or keeps tracking accuracy less than 33.89 Hz,the experimental results show that the proposed method can not only keep tracking,but also achieve tracking accuracy more than 2.77 Hz.展开更多
目的:探究应用超临界CO2流体沉析技术制备石榴皮总多酚脂质体的工艺条件,为该制剂的工业化生产提供参考。方法:以包封率为评价指标,通过Plackett-Burman试验筛选主要影响因素,利用最陡爬坡试验和Box-Behnken试验优选石榴皮总多酚脂质体...目的:探究应用超临界CO2流体沉析技术制备石榴皮总多酚脂质体的工艺条件,为该制剂的工业化生产提供参考。方法:以包封率为评价指标,通过Plackett-Burman试验筛选主要影响因素,利用最陡爬坡试验和Box-Behnken试验优选石榴皮总多酚脂质体的制备工艺。结果:原药与膜材的质量比、反应温度和反应压力是影响总多酚脂质体包封率的显著性因素,最佳制备工艺条件为原药-膜材的质量比1∶21.15,反应温度48.3℃,反应压力23.88 MPa。包封率实测值80.295%和预测值81.379%的偏差1.33%,有效粒度168.5 nm,Zeta电位-73.8 m V。结论:该试验模型设计达到要求,工艺具有可行性。石榴皮总多酚脂质体体外释放速度缓慢,缓释效果明显,稳定性良好。展开更多
基金funded by National Natural Science Foundation of China(Nos.61533008,61603181,61673208,61873125)。
文摘High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adaptability for high dynamics require either complicated structures or prior statistical information of noises.This paper proposes a high dynamics algorithm based on steepest ascent method that can circumvent the deficiencies of existing methods.First,the relationship between the error of carrier tracking and the maximum of Fast Fourier Transform(FFT)outputs is established,and a performance function based on the steepest ascent method is designed.It can keep stable in high dynamics.Second,a new carrier-tracking loop is constructed by deploying the performance function.When the variation of GPS receiver acceleration ranges from 10 g to 100 g,compared with the PLL that either loses lock or keeps tracking accuracy less than 33.89 Hz,the experimental results show that the proposed method can not only keep tracking,but also achieve tracking accuracy more than 2.77 Hz.
文摘目的:探究应用超临界CO2流体沉析技术制备石榴皮总多酚脂质体的工艺条件,为该制剂的工业化生产提供参考。方法:以包封率为评价指标,通过Plackett-Burman试验筛选主要影响因素,利用最陡爬坡试验和Box-Behnken试验优选石榴皮总多酚脂质体的制备工艺。结果:原药与膜材的质量比、反应温度和反应压力是影响总多酚脂质体包封率的显著性因素,最佳制备工艺条件为原药-膜材的质量比1∶21.15,反应温度48.3℃,反应压力23.88 MPa。包封率实测值80.295%和预测值81.379%的偏差1.33%,有效粒度168.5 nm,Zeta电位-73.8 m V。结论:该试验模型设计达到要求,工艺具有可行性。石榴皮总多酚脂质体体外释放速度缓慢,缓释效果明显,稳定性良好。
