on the basis of analyzing the characteristics of low light level(LLL)image and ultra-violet image and the information amount of dual channel color night vision system,the LLL and ultra-violet color night vision techni...on the basis of analyzing the characteristics of low light level(LLL)image and ultra-violet image and the information amount of dual channel color night vision system,the LLL and ultra-violet color night vision technique is put forward.The methods of gray-scale modulation,frequency field fusion,special component fusion arc tried,and the improved LLL and ultra-violet image pseudo color fusion algorithms are presented.These new algorithms include subsection gray-scale modulation,image difference picking-up,component separation based on the reflected characteristics to night skylight reflection characteristics of objects and color space mapping which embodies the spectrum response of image sensor and nature vision.Some good results are obtained.展开更多
Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neopho...Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis),once commonly observed in the Yangtze River-Poyang Lake junction,is now rarely seen in the river-lake corridor.In this study,static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor.Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation,as well as environmental variables,including hydrological conditions and light levels.Over approximately three consecutive years of monitoring(2020–2022),porpoise biosonar was detected during 93%of logged days,indicating the key role of the corridor for finless porpoise conservation.In addition,porpoise clicks were recorded in 3.80%of minutes,while feeding correlated buzzes were detected in 1.23%of minutes,suggesting the potential existence of localized,small-scale migration.Furthermore,both anthropogenic and environmental variables were significantly correlated with the diel,lunar,monthly,seasonal,and annual variations in porpoise biosonar activities.During the pandemic lockdown period,porpoise sonar detection showed a significant increase.Furthermore,a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity.In addition to water level and flux,daylight and moonlight exhibited significant correlations with porpoise biosonar activities,with markedly higher detections at night and quarter moon periods.Ensuring the spatiotemporal reduction of anthropogenic activities,implementing vessel speed restrictions(e.g.,during porpoise migration and feeding),and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability.展开更多
A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the...A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the basis of the model created. Three uniform random sequences are built by the linear congruential method, of which two are used to form integer number and decimal fraction parts of the new random sequence respectively and the third to shuffle the new sequence. And then a Gauss sequence is formed out of uniform distribution by a function transforming method. It actualizes the simulation in real time of quantum noise in the low light imaging system, where video flow is extracted in real time, the noise summed up and played back side by side with the original video signs by a simulation software.展开更多
A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on differe...A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on difference processing. To obtain spatial relativity, images are shifted according to the motion parameters. As a result, the processing of integral and average can be applied to images that have been shifted. The technique of frame shift and integral that includes the algorithm of motion parameter determination is discussed, experiments with low light level moving image sequences are also described. The experiment results show the effectiveness and the robustness of the parameter determination algorithm, and the improvement in the signal-to-noise ratio （SNR） of low light level moving images.展开更多
In this paper a Y-type four-level atom interacting with external fields system is investigated. It is shown that increasing the control field can reduce the probe absorption, the electromagnetically induced transparen...In this paper a Y-type four-level atom interacting with external fields system is investigated. It is shown that increasing the control field can reduce the probe absorption, the electromagnetically induced transparency (EIT) and gain can be obtained if the parameters are taken appropriately. An interesting phenomenon is found that the system appears to be probe gain in a large region if the external fields Rabi phases are taken appropriately, too.展开更多
The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had posit...The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had positive response to the four indicators of mitochondrial membrane potential,ATP release,cell migration and collagen synthesis was screened.The experimental results showed that low level red light with a irradiation dose of 2 J/cm^(2) had a positive response to the above four indexes in fibroblast.The test model on fibroblast was later transferred to dermal papilla cells for further experimental verification.The results showed that low level red light with a irradiation dose of 2 J/cm^(2) also had a positive response to the four indicators of dermal papilla cells,namely,mitochondrial membrane potential,ATP release,cell proliferation rate and collagen synthesis.It is proved that the low level red light with a irradiation dose of 2 J/cm^(2) could improve the mitochondrial function,cell migration and collagen synthesis of fibroblast and dermal papilla cell,thus providing energy for cell activities,improving cell repair ability and cell anti-aging ability.展开更多
We study the optical properties of a two-level atomic ensemble controlled by a high-finesse cavity. Even though the cavity is initially in the vacuum state in the absence of external driving, the probe response of the...We study the optical properties of a two-level atomic ensemble controlled by a high-finesse cavity. Even though the cavity is initially in the vacuum state in the absence of external driving, the probe response of the atomic ensemble can be dramatically modified. When the collectively enhanced atom–cavity coupling is strong enough and the cavity decay rate is much smaller than the atomic damping rate, an electromagnetically induced transparency-like coherent phenomenon emerges with a dip absorption for the response of the two-level atoms in the cavity without driving, and thus is called vacuum induced transparency. We also show the slow light with very low group velocity in such an atomic ensemble.展开更多
The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the b...The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the both illumination modes. The results show for both illumination modes that diffusion parameters decrease with increasing doping level. These results are in agreement with the studies of the current and the voltage which showed for the two illumination modes that doping level increase leads to a decrease in current density and an increase in voltage. It also emerges for the two illumination modes and for the doping range 10<sup>13</sup> cm<sup>-3</sup> - 10<sup>16</sup> cm<sup>-3</sup>, a decrease of maximum power and conversion efficiency. The results also show that decrease of diffusion parameters is faster under moderate concentration in comparison with normal illumination. These results predict a greater variation rate of the current, the voltage, the maximum power and the conversion efficiency under moderate concentration compared to normal illumination. Contrary to diffusion parameters study, the results show higher variation rates of parameters under normal illumination. This is explained by the fact that under moderate concentration, carriers density is close to doping level: the cell is then in high injection condition. Consequently, under moderate concentration, carriers density is less sensitive to doping level variations. The study confirms that carriers density variation with the doping level is weak under the moderate concentration compared to normal illumination.展开更多
Young adult sleep quality is reported to be compromised in the literature with shortened sleep intervals, daytime napping, excessive daytime sleepiness and excessive wakeups. The description of young adult sleep quali...Young adult sleep quality is reported to be compromised in the literature with shortened sleep intervals, daytime napping, excessive daytime sleepiness and excessive wakeups. The description of young adult sleep quality commonly includes the rationale that the independent schedule of the young adults coupled with their preferred social schedule, work and academic schedules leaves the planning for sleep to last place. Despite mentation and memory reductions with sleep deprivation secondary to poor sleep quality documented in young adults, the poor sleep quality prevails. This study is focused on the elements of arousal during a young adult’s day that may predispose them to elevated activation and difficulty relaxing sufficiently to fall asleep. It was hypothesized that light exposure was elevated in young adults with poor sleep quality. Light exposure in terms of overhead bright lights in classrooms and laboratories of the academic environment, bright light in terms of video monitors/TVs/tablets/phone exposure is sufficiently stimulating to cause cognitive activation was light exposure.展开更多
近年来,重复低强度红光疗法(repeated low-level red light therapy,RLRL)作为一种新兴的近视干预手段,在延缓眼轴增长和屈光度数加深方面展现出显著效果。大量临床研究证实其疗效优于阿托品及角膜塑形镜,然而其作用机制及长期安全性尚...近年来,重复低强度红光疗法(repeated low-level red light therapy,RLRL)作为一种新兴的近视干预手段,在延缓眼轴增长和屈光度数加深方面展现出显著效果。大量临床研究证实其疗效优于阿托品及角膜塑形镜,然而其作用机制及长期安全性尚不明确。基础研究表明RLRL可能通过利用纵向色差原理、调节视网膜多巴胺分泌、增加脉络膜厚度及血流灌注、改善巩膜缺氧、减轻炎症和氧化应激反应等多种途径控制近视进展。安全性方面,多数研究表明其短期安全性良好,但最新高分辨率成像研究提示潜在视网膜视锥细胞密度降低风险,且停用后存在反弹效应。本文对RLRL控制近视的作用机制、临床有效性和安全性进行综述,以期为临床应用提供参考。展开更多
文摘on the basis of analyzing the characteristics of low light level(LLL)image and ultra-violet image and the information amount of dual channel color night vision system,the LLL and ultra-violet color night vision technique is put forward.The methods of gray-scale modulation,frequency field fusion,special component fusion arc tried,and the improved LLL and ultra-violet image pseudo color fusion algorithms are presented.These new algorithms include subsection gray-scale modulation,image difference picking-up,component separation based on the reflected characteristics to night skylight reflection characteristics of objects and color space mapping which embodies the spectrum response of image sensor and nature vision.Some good results are obtained.
基金supported by Science and Technology Service Network Initiative Program of the Chinese Academy of Sciencesthe National Natural Science Foundation of China (41806197)the Exploratory Program of the Natural Science Foundation of Zhejiang Province (ZX2023000154)。
文摘Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis),once commonly observed in the Yangtze River-Poyang Lake junction,is now rarely seen in the river-lake corridor.In this study,static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor.Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation,as well as environmental variables,including hydrological conditions and light levels.Over approximately three consecutive years of monitoring(2020–2022),porpoise biosonar was detected during 93%of logged days,indicating the key role of the corridor for finless porpoise conservation.In addition,porpoise clicks were recorded in 3.80%of minutes,while feeding correlated buzzes were detected in 1.23%of minutes,suggesting the potential existence of localized,small-scale migration.Furthermore,both anthropogenic and environmental variables were significantly correlated with the diel,lunar,monthly,seasonal,and annual variations in porpoise biosonar activities.During the pandemic lockdown period,porpoise sonar detection showed a significant increase.Furthermore,a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity.In addition to water level and flux,daylight and moonlight exhibited significant correlations with porpoise biosonar activities,with markedly higher detections at night and quarter moon periods.Ensuring the spatiotemporal reduction of anthropogenic activities,implementing vessel speed restrictions(e.g.,during porpoise migration and feeding),and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability.
文摘A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the basis of the model created. Three uniform random sequences are built by the linear congruential method, of which two are used to form integer number and decimal fraction parts of the new random sequence respectively and the third to shuffle the new sequence. And then a Gauss sequence is formed out of uniform distribution by a function transforming method. It actualizes the simulation in real time of quantum noise in the low light imaging system, where video flow is extracted in real time, the noise summed up and played back side by side with the original video signs by a simulation software.
文摘A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on difference processing. To obtain spatial relativity, images are shifted according to the motion parameters. As a result, the processing of integral and average can be applied to images that have been shifted. The technique of frame shift and integral that includes the algorithm of motion parameter determination is discussed, experiments with low light level moving image sequences are also described. The experiment results show the effectiveness and the robustness of the parameter determination algorithm, and the improvement in the signal-to-noise ratio （SNR） of low light level moving images.
基金supported by the National Natural Science Foundation of China(Grant Nos.10464002 and 60278016).
文摘In this paper a Y-type four-level atom interacting with external fields system is investigated. It is shown that increasing the control field can reduce the probe absorption, the electromagnetically induced transparency (EIT) and gain can be obtained if the parameters are taken appropriately. An interesting phenomenon is found that the system appears to be probe gain in a large region if the external fields Rabi phases are taken appropriately, too.
文摘The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had positive response to the four indicators of mitochondrial membrane potential,ATP release,cell migration and collagen synthesis was screened.The experimental results showed that low level red light with a irradiation dose of 2 J/cm^(2) had a positive response to the above four indexes in fibroblast.The test model on fibroblast was later transferred to dermal papilla cells for further experimental verification.The results showed that low level red light with a irradiation dose of 2 J/cm^(2) also had a positive response to the four indicators of dermal papilla cells,namely,mitochondrial membrane potential,ATP release,cell proliferation rate and collagen synthesis.It is proved that the low level red light with a irradiation dose of 2 J/cm^(2) could improve the mitochondrial function,cell migration and collagen synthesis of fibroblast and dermal papilla cell,thus providing energy for cell activities,improving cell repair ability and cell anti-aging ability.
基金Project supported by the National Natural Science Foundation of China(Grant No.11304010)
文摘We study the optical properties of a two-level atomic ensemble controlled by a high-finesse cavity. Even though the cavity is initially in the vacuum state in the absence of external driving, the probe response of the atomic ensemble can be dramatically modified. When the collectively enhanced atom–cavity coupling is strong enough and the cavity decay rate is much smaller than the atomic damping rate, an electromagnetically induced transparency-like coherent phenomenon emerges with a dip absorption for the response of the two-level atoms in the cavity without driving, and thus is called vacuum induced transparency. We also show the slow light with very low group velocity in such an atomic ensemble.
文摘The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the both illumination modes. The results show for both illumination modes that diffusion parameters decrease with increasing doping level. These results are in agreement with the studies of the current and the voltage which showed for the two illumination modes that doping level increase leads to a decrease in current density and an increase in voltage. It also emerges for the two illumination modes and for the doping range 10<sup>13</sup> cm<sup>-3</sup> - 10<sup>16</sup> cm<sup>-3</sup>, a decrease of maximum power and conversion efficiency. The results also show that decrease of diffusion parameters is faster under moderate concentration in comparison with normal illumination. These results predict a greater variation rate of the current, the voltage, the maximum power and the conversion efficiency under moderate concentration compared to normal illumination. Contrary to diffusion parameters study, the results show higher variation rates of parameters under normal illumination. This is explained by the fact that under moderate concentration, carriers density is close to doping level: the cell is then in high injection condition. Consequently, under moderate concentration, carriers density is less sensitive to doping level variations. The study confirms that carriers density variation with the doping level is weak under the moderate concentration compared to normal illumination.
文摘Young adult sleep quality is reported to be compromised in the literature with shortened sleep intervals, daytime napping, excessive daytime sleepiness and excessive wakeups. The description of young adult sleep quality commonly includes the rationale that the independent schedule of the young adults coupled with their preferred social schedule, work and academic schedules leaves the planning for sleep to last place. Despite mentation and memory reductions with sleep deprivation secondary to poor sleep quality documented in young adults, the poor sleep quality prevails. This study is focused on the elements of arousal during a young adult’s day that may predispose them to elevated activation and difficulty relaxing sufficiently to fall asleep. It was hypothesized that light exposure was elevated in young adults with poor sleep quality. Light exposure in terms of overhead bright lights in classrooms and laboratories of the academic environment, bright light in terms of video monitors/TVs/tablets/phone exposure is sufficiently stimulating to cause cognitive activation was light exposure.
文摘近年来,重复低强度红光疗法(repeated low-level red light therapy,RLRL)作为一种新兴的近视干预手段,在延缓眼轴增长和屈光度数加深方面展现出显著效果。大量临床研究证实其疗效优于阿托品及角膜塑形镜,然而其作用机制及长期安全性尚不明确。基础研究表明RLRL可能通过利用纵向色差原理、调节视网膜多巴胺分泌、增加脉络膜厚度及血流灌注、改善巩膜缺氧、减轻炎症和氧化应激反应等多种途径控制近视进展。安全性方面,多数研究表明其短期安全性良好,但最新高分辨率成像研究提示潜在视网膜视锥细胞密度降低风险,且停用后存在反弹效应。本文对RLRL控制近视的作用机制、临床有效性和安全性进行综述,以期为临床应用提供参考。
