Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitud...Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying effects.Dependency of the decoying effect on corner reflectors’radar cross section and positions are analyzed and simulated.Results show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.展开更多
AIM:To investigate the relationship between dynamic tear meniscus parameters and dry eye using an automated tear meniscus segmentation method.METHODS:The analysis of tear meniscus videos captured within 5s after a com...AIM:To investigate the relationship between dynamic tear meniscus parameters and dry eye using an automated tear meniscus segmentation method.METHODS:The analysis of tear meniscus videos captured within 5s after a complete blink includes data from 38 participates.By processing video data,several key parameters including the average height of the tear meniscus at different lengths,the curvature of the tear meniscus’s upper boundary,and the total area of the tear meniscus in each frame were calculated.The effective values of these dynamic parameters were then linearly fitted to explore the relationship between their changing trends and dry eye disease.RESULTS:In 94.74%of the samples,the average height of central tear meniscus increased over time.Moreover,97.37%of the samples exhibited an increase in the overall tear meniscus height(TMH)and area from the nasal to temporal side.Notably,the central TMH increased at a faster rate compared to the nasal side with the temporal side showing the slowest ascent.Statistical analysis indicates that the upper boundary curvature of the whole tear meniscus as well as the tear meniscus of the nasal side(2,3,and 4 mm)aid in identifying the presence of dry eye and assessing its severity.CONCLUSION:This study contributes to the understanding of tear meniscus dynamics as potential markers for dry eye,utilizing an automated and non-invasive approach that has implications for clinical assessment.展开更多
Super-resolution optical fluctuation imaging is dependent on the blinking frequency of fluorophores.Consequently,improvement of the photoluminescence(PL)blink frequency is important.This is achieved for 3C–SiC nanocr...Super-resolution optical fluctuation imaging is dependent on the blinking frequency of fluorophores.Consequently,improvement of the photoluminescence(PL)blink frequency is important.This is achieved for 3C–SiC nanocrystals(NCs)by simply increasing the excitation power.Using an excitation of 488 nm with powers of 5μW to 50μW,individual 3C–SiC NC always exhibits PL blinking with a short on-state sojourn time(<0.1 s).A fast Fourier transform method is exploited to determine the PL switching frequency.It is found that the frequency of the bright state increases from 2 Hz to 20 Hz as the excitation power increases from 5μW to 50μW,which is explained by the Auger photonionization model.展开更多
The photostability of a colloidal single photon emitter in near-infrared regime at room temperature is investigated.The fluorescence lifetime,blinking phenomenon,and anti-bunching effect of a single CdTeSe/ZnS quantum...The photostability of a colloidal single photon emitter in near-infrared regime at room temperature is investigated.The fluorescence lifetime,blinking phenomenon,and anti-bunching effect of a single CdTeSe/ZnS quantum dot with an emission wavelength of 800 nm at room temperature are studied.The second-order correlation function at zero delay time is much smaller than 0.1,which proves that the emission from single quantum dots at 800 nm is a highly pure single-photon source.The effects of the irradiation duration on the fluorescence from single quantum dots are analyzed.The experimental results can be explained by a recombination model including a multi-nonradiative recombination center model and a multi-charged model.展开更多
基金supported by the Equipment Pre-research Project(GK202002A020068)。
文摘Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying effects.Dependency of the decoying effect on corner reflectors’radar cross section and positions are analyzed and simulated.Results show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.
基金Supported by Medical-Engineering Interdisciplinary Research Foundation of Shenzhen University and Research Development Fund of Beijing Municipal Health Commission(No.2019-4).
文摘AIM:To investigate the relationship between dynamic tear meniscus parameters and dry eye using an automated tear meniscus segmentation method.METHODS:The analysis of tear meniscus videos captured within 5s after a complete blink includes data from 38 participates.By processing video data,several key parameters including the average height of the tear meniscus at different lengths,the curvature of the tear meniscus’s upper boundary,and the total area of the tear meniscus in each frame were calculated.The effective values of these dynamic parameters were then linearly fitted to explore the relationship between their changing trends and dry eye disease.RESULTS:In 94.74%of the samples,the average height of central tear meniscus increased over time.Moreover,97.37%of the samples exhibited an increase in the overall tear meniscus height(TMH)and area from the nasal to temporal side.Notably,the central TMH increased at a faster rate compared to the nasal side with the temporal side showing the slowest ascent.Statistical analysis indicates that the upper boundary curvature of the whole tear meniscus as well as the tear meniscus of the nasal side(2,3,and 4 mm)aid in identifying the presence of dry eye and assessing its severity.CONCLUSION:This study contributes to the understanding of tear meniscus dynamics as potential markers for dry eye,utilizing an automated and non-invasive approach that has implications for clinical assessment.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604155,11604147,and 51702379)China Postdoctoral Science Foundation(Grant Nos.2016M600428 and 2017T100386)the Planned Projects for Postdoctoral Research Funds of China(Grant No.1601023A)
文摘Super-resolution optical fluctuation imaging is dependent on the blinking frequency of fluorophores.Consequently,improvement of the photoluminescence(PL)blink frequency is important.This is achieved for 3C–SiC nanocrystals(NCs)by simply increasing the excitation power.Using an excitation of 488 nm with powers of 5μW to 50μW,individual 3C–SiC NC always exhibits PL blinking with a short on-state sojourn time(<0.1 s).A fast Fourier transform method is exploited to determine the PL switching frequency.It is found that the frequency of the bright state increases from 2 Hz to 20 Hz as the excitation power increases from 5μW to 50μW,which is explained by the Auger photonionization model.
基金Project supported by the National Natural Science Foundation of China(Grant No.92165202)the Innovation Program for Quantum Science and Technology,China(Grant No.2021ZD0300701)the Strategic Priority Research Program(A)of Chinese Academy of Sciences(Grant No.XDA18040300).
文摘The photostability of a colloidal single photon emitter in near-infrared regime at room temperature is investigated.The fluorescence lifetime,blinking phenomenon,and anti-bunching effect of a single CdTeSe/ZnS quantum dot with an emission wavelength of 800 nm at room temperature are studied.The second-order correlation function at zero delay time is much smaller than 0.1,which proves that the emission from single quantum dots at 800 nm is a highly pure single-photon source.The effects of the irradiation duration on the fluorescence from single quantum dots are analyzed.The experimental results can be explained by a recombination model including a multi-nonradiative recombination center model and a multi-charged model.
