Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution e...Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution enhancement can only increase the spatial resolution of micros-copy by a factor of two at most because the frequency of the structured illumination pattern is limited by the cutoff frequency of the excitation point spread function.The frequency of the pattern generated by the nonlinear response in samples is not limited;therefore,nonlinear SIM(NL-SIM),in theory,has no inherent limit to the resolution.In the present study,we describe a two-photon nonlinear SIM(2P-SIM)technique using a multiple harmonics scanning pattern that employs a composite structured illumination pattern,which can produce a higher order harmonic pattern based on the fluorescence nonlinear response in a 2P process.The theoretical models of super-resolution imaging were established through our simulation,which describes the working mechanism of the multi-frequency structure of the nonsinusoidal function to improve the reso-lution.The simulation results predict that a 5-fold improvement in resolution in the 2P-SIM is possible.展开更多
基于最小错误概率准则,设计了非正弦时域正交调制信号的解调模型,理论分析了加性白色高斯噪声(additive white Gaussian noise,AWGN)信道下通信系统的差错性能。结果表明,非正弦时域正交调制可达到与正交频分复用(orthogonal frequency ...基于最小错误概率准则,设计了非正弦时域正交调制信号的解调模型,理论分析了加性白色高斯噪声(additive white Gaussian noise,AWGN)信道下通信系统的差错性能。结果表明,非正弦时域正交调制可达到与正交频分复用(orthogonal frequency division multiplexing,OFDM)相同的差错性能,且其单位频带利用率的提升速度优于OFDM。复杂度分析结果表明,其解调复杂度虽然高于OFDM,但仍具有硬件可实现性,可用于长波至超短波的通信频段。展开更多
为更好地应用电力有源滤波器技术,通过最优化数学模型的建立介绍了瞬时无功功率理论的基本内容,所谓瞬时有功电流即保证三相瞬时总能量不变而三相传输损失最小的电流;空间基变换证明,电压和电流瞬时值从a b c三相变换到αβο三相为正...为更好地应用电力有源滤波器技术,通过最优化数学模型的建立介绍了瞬时无功功率理论的基本内容,所谓瞬时有功电流即保证三相瞬时总能量不变而三相传输损失最小的电流;空间基变换证明,电压和电流瞬时值从a b c三相变换到αβο三相为正交变换,说明三相三线制系统或无零序电压电流时三相到两相变换的合理性,从而将αβ变换与d q变换联系起来。最后指明系统电压畸变时不宜用基于该理论的谐波检测和无功补偿方法。展开更多
基金This work Was supported by National Natural Science Foundation of China(grant nos.61775148,61527827,and 61905145)Guangdong Natural Science Foundation and Province Project(2021A1515011916)Shenzhen Science and Technology R&D and Innovation Foundation(grant nos.JCYJ20200109105608771.J CYJ20180305124754860 and JCYJ20180228162956597).
文摘Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution enhancement can only increase the spatial resolution of micros-copy by a factor of two at most because the frequency of the structured illumination pattern is limited by the cutoff frequency of the excitation point spread function.The frequency of the pattern generated by the nonlinear response in samples is not limited;therefore,nonlinear SIM(NL-SIM),in theory,has no inherent limit to the resolution.In the present study,we describe a two-photon nonlinear SIM(2P-SIM)technique using a multiple harmonics scanning pattern that employs a composite structured illumination pattern,which can produce a higher order harmonic pattern based on the fluorescence nonlinear response in a 2P process.The theoretical models of super-resolution imaging were established through our simulation,which describes the working mechanism of the multi-frequency structure of the nonsinusoidal function to improve the reso-lution.The simulation results predict that a 5-fold improvement in resolution in the 2P-SIM is possible.
文摘基于最小错误概率准则,设计了非正弦时域正交调制信号的解调模型,理论分析了加性白色高斯噪声(additive white Gaussian noise,AWGN)信道下通信系统的差错性能。结果表明,非正弦时域正交调制可达到与正交频分复用(orthogonal frequency division multiplexing,OFDM)相同的差错性能,且其单位频带利用率的提升速度优于OFDM。复杂度分析结果表明,其解调复杂度虽然高于OFDM,但仍具有硬件可实现性,可用于长波至超短波的通信频段。
文摘为更好地应用电力有源滤波器技术,通过最优化数学模型的建立介绍了瞬时无功功率理论的基本内容,所谓瞬时有功电流即保证三相瞬时总能量不变而三相传输损失最小的电流;空间基变换证明,电压和电流瞬时值从a b c三相变换到αβο三相为正交变换,说明三相三线制系统或无零序电压电流时三相到两相变换的合理性,从而将αβ变换与d q变换联系起来。最后指明系统电压畸变时不宜用基于该理论的谐波检测和无功补偿方法。
