为研究扫频波对连续波Doppler引信的效应规律及作用机理,开展了典型引信扫频波辐照效应试验,结合现有文献研究结论,提出了普适的扫频波辐照下连续波Doppler引信效应规律及作用机理。试验结果表明:扫频波辐照下引信会意外发火,引信临界...为研究扫频波对连续波Doppler引信的效应规律及作用机理,开展了典型引信扫频波辐照效应试验,结合现有文献研究结论,提出了普适的扫频波辐照下连续波Doppler引信效应规律及作用机理。试验结果表明:扫频波辐照下引信会意外发火,引信临界干扰电场强度与扫频频段有关;扫频步长、频点驻留时间与引信是否意外发火密切相关,受试引信意外发火时要求扫频步长≥7 k Hz,频点驻留时间≤483 ms;扫频参数不会影响受试引信临界干扰电场强度。扫频波辐照下连续波Doppler引信意外发火原因为:扫频波频率变化导致引信自差机振荡状态发生跳变,引起高频电路输出电压波动,从而推动执行级误动作。展开更多
为研究步进式扫频波（SSFW）对某型分米波引信的干扰规律,理论推导并分析了步进式扫频波干扰下引信的启动特性,开展了辐照效应试验,确定了受试引信步进式扫频波干扰规律和机理。研究结果表明：（1）步进式扫频波可以使受试引信意外发火;...为研究步进式扫频波（SSFW）对某型分米波引信的干扰规律,理论推导并分析了步进式扫频波干扰下引信的启动特性,开展了辐照效应试验,确定了受试引信步进式扫频波干扰规律和机理。研究结果表明：（1）步进式扫频波可以使受试引信意外发火;（2）引信对步进式扫频波的敏感因素包括扫频频段、扫频步长、能量和频点驻留时间;（3）扫频步长和频点驻留时间分别影响引信检波电压脉冲幅值与重复周期,在其他参数满足要求的前提下,受试引信意外发火时要求扫频步长≥3 k Hz,频点驻留时间≤20 ms;（4）受试引信临界干扰场强不受扫频参数的影响;（5）扫频波对受试引信的干扰机理为：扫频波频率变化导致引信自差机振荡状态发生跳变,引起高频电路输出电压波动,进而推动引信执行电路误动作。展开更多
穿墙探测所处的外界环境内通常存在多种散射体,是否存在金属物品、有无人体对墙体参数反演具有不同的影响,进而影响穿墙定位与成像的准确性。将不同的外界环境分为不同场景,根据电磁波传播理论和菲涅尔公式建立电磁波穿墙传播模型,并详...穿墙探测所处的外界环境内通常存在多种散射体,是否存在金属物品、有无人体对墙体参数反演具有不同的影响,进而影响穿墙定位与成像的准确性。将不同的外界环境分为不同场景,根据电磁波传播理论和菲涅尔公式建立电磁波穿墙传播模型,并详细阐述了用于提高步进扫频连续波(stepped frequency continuous wave,SFCW)穿墙雷达分辨率的Extend Prony算法和墙体参数快速反演算法,得出一种反演墙体介电常数和厚度的方法,并在墙后无散射体场景、墙后存在金属物体场景和墙后存在人体场景多场景中进行实验,最后将真实值与实验结果对比,表明在不同场景中具有较强适应性,反演出的墙体参数是现场穿墙探测的重要参考依据。展开更多
One of the most important electron density diagnostics, microwave reflectometry, has been developed on many large and medium nuclear fusion devices in recent years . Not only the electron density profiles with high te...One of the most important electron density diagnostics, microwave reflectometry, has been developed on many large and medium nuclear fusion devices in recent years . Not only the electron density profiles with high temporal and spatial resolutions, but also the profiles of plasma rotation and turbulence can be obtained with this diagnostic system.展开更多
A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC)....A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC).Thirty-seven primary open-angle glaucoma patients were divided into two groups depending on the patients having been treated or not.The statistical results showed that there were significant differences between the treated and untreated groups’SC areas(treated,7935.6875±680.003μm2;untreated,3890.71875±871.49844μm2;P<0.001),the circumferences(treated,580.37891±44.96529μm;untreated,381.9026±41.22123μm;P<0.001),and the long diameters(treated,272.87806±25.7254μm;untreated,185.24047±19.72786μm;P<0.001).We hypothesize that,after drug treatment,the SC will expand and the morphometric values especially the areas will become larger,thus helping to reduce intraocular pressure.展开更多
文摘为研究扫频波对连续波Doppler引信的效应规律及作用机理,开展了典型引信扫频波辐照效应试验,结合现有文献研究结论,提出了普适的扫频波辐照下连续波Doppler引信效应规律及作用机理。试验结果表明:扫频波辐照下引信会意外发火,引信临界干扰电场强度与扫频频段有关;扫频步长、频点驻留时间与引信是否意外发火密切相关,受试引信意外发火时要求扫频步长≥7 k Hz,频点驻留时间≤483 ms;扫频参数不会影响受试引信临界干扰电场强度。扫频波辐照下连续波Doppler引信意外发火原因为:扫频波频率变化导致引信自差机振荡状态发生跳变,引起高频电路输出电压波动,从而推动执行级误动作。
文摘为研究步进式扫频波（SSFW）对某型分米波引信的干扰规律,理论推导并分析了步进式扫频波干扰下引信的启动特性,开展了辐照效应试验,确定了受试引信步进式扫频波干扰规律和机理。研究结果表明：（1）步进式扫频波可以使受试引信意外发火;（2）引信对步进式扫频波的敏感因素包括扫频频段、扫频步长、能量和频点驻留时间;（3）扫频步长和频点驻留时间分别影响引信检波电压脉冲幅值与重复周期,在其他参数满足要求的前提下,受试引信意外发火时要求扫频步长≥3 k Hz,频点驻留时间≤20 ms;（4）受试引信临界干扰场强不受扫频参数的影响;（5）扫频波对受试引信的干扰机理为：扫频波频率变化导致引信自差机振荡状态发生跳变,引起高频电路输出电压波动,进而推动引信执行电路误动作。
文摘穿墙探测所处的外界环境内通常存在多种散射体,是否存在金属物品、有无人体对墙体参数反演具有不同的影响,进而影响穿墙定位与成像的准确性。将不同的外界环境分为不同场景,根据电磁波传播理论和菲涅尔公式建立电磁波穿墙传播模型,并详细阐述了用于提高步进扫频连续波(stepped frequency continuous wave,SFCW)穿墙雷达分辨率的Extend Prony算法和墙体参数快速反演算法,得出一种反演墙体介电常数和厚度的方法,并在墙后无散射体场景、墙后存在金属物体场景和墙后存在人体场景多场景中进行实验,最后将真实值与实验结果对比,表明在不同场景中具有较强适应性,反演出的墙体参数是现场穿墙探测的重要参考依据。
文摘One of the most important electron density diagnostics, microwave reflectometry, has been developed on many large and medium nuclear fusion devices in recent years . Not only the electron density profiles with high temporal and spatial resolutions, but also the profiles of plasma rotation and turbulence can be obtained with this diagnostic system.
基金supported by the Sichuan Youth Science&Technology Foundation(2013JQ0028)the National Natural Science Foundation of China(61108082)+1 种基金the West Light Foundation of the Chinese Academy of Sciencesthe National Major Scientific Equipment Program(2012YQ120080)
文摘A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC).Thirty-seven primary open-angle glaucoma patients were divided into two groups depending on the patients having been treated or not.The statistical results showed that there were significant differences between the treated and untreated groups’SC areas(treated,7935.6875±680.003μm2;untreated,3890.71875±871.49844μm2;P<0.001),the circumferences(treated,580.37891±44.96529μm;untreated,381.9026±41.22123μm;P<0.001),and the long diameters(treated,272.87806±25.7254μm;untreated,185.24047±19.72786μm;P<0.001).We hypothesize that,after drug treatment,the SC will expand and the morphometric values especially the areas will become larger,thus helping to reduce intraocular pressure.
