Supplemental lighting has emerged as a widely adopted technique in greenhouse cultivation to enhance product visibility andimprove theflavor characteristics ofChinese bayberry(Myrica rubra)in the internationalmarket.W...Supplemental lighting has emerged as a widely adopted technique in greenhouse cultivation to enhance product visibility andimprove theflavor characteristics ofChinese bayberry(Myrica rubra)in the internationalmarket.While studies on lighting have predominantly focused on colorimetry,limited research has addressed the precise control of chromatic parameters and their effect on fruit quality.This study examined the effects of varying lighting conditions,specifically correlated color temperatures and illuminance,on the growth and quality of Chinese bayberry varieties“Black Charcoal”and“Dongkui”using a precision control system.The bayberry plants were exposed to a constant illuminance of 155μmol·m^(-2)·s^(-1) with chromatic levels ranging from 2250 to 6000 K.Black Charcoal demonstrated substantial improvements under different chromatic parameters,with fruit weight and size increasing by 40%and 14%,respectively.Furthermore,soluble solids content increased by 4% and vitamin C content rose by 142%,while organic acid content decreased by 30%.Dongkui,however,showed more modest responses under identical conditions,with fruit weight increasing by 2% and fruit size decreasing by 1%.Soluble solids and vitamin C contents showed minimal increases of 2% and 2.5%,respectively,while organic acid content decreased by 8%.The findings demonstrate that supplemental LED lighting significantly enhances both yield and quality parameters in Black Charcoal compared with Dongkui.These results provide valuable insights for optimizing Chinese bayberry cultivation,and the precise control methodology developed can be used to improve supplemental lighting strategies in other fruit and plant species.展开更多
The challenges and opportunities for developing sustainable plant factories with artificial lighting(PFALs)are discussed.After examining the production cost and productivity of existing PFALs in Japan,the possibility ...The challenges and opportunities for developing sustainable plant factories with artificial lighting(PFALs)are discussed.After examining the production cost and productivity of existing PFALs in Japan,the possibility of introducing a relatively new concept and methodology for considerably improving productivity are discussed in relation to environmental controllability and resource use efficiencies.The fundamental and potential characteristics of ideal or next-generation PFALs(n-PFALs)are then discussed with some suggestions for actualizing n-PFALs.Finally,perspectives of the n-PFALs and technologies to be integrated into the n-PFALs are presented in relation to the Sustainable Development Goals(SDGs)to be achieved by 2030.展开更多
AIM:To assess the efficacy of artificial natural light in preventing incident myopia in primary school-age children.METHODS:This is a prospective,randomized control,intervention study.A total of 1840 students from 39 ...AIM:To assess the efficacy of artificial natural light in preventing incident myopia in primary school-age children.METHODS:This is a prospective,randomized control,intervention study.A total of 1840 students from 39 classes in 4 primary schools in Foshan participated in this study.The whole randomization method was adopted to include classes as a group according to 1:1 randomized control.Classrooms in the control group were illuminated by usual light,and classrooms in the intervention group were illuminated by artificial natural light.All students received uncorrected visual acuity and best-corrected visual acuity measurement,non-cycloplegic autorefraction,ocular biometric examination,slit lamp and strabismus examination.Three-year follow-up,the students underwent same procedures.Myopia was defined as spherical equivalent refraction≤-0.50 D and uncorrected visual acuity<20/20.RESULTS:There were 894 students in the control group and 946 students in the intervention group with a mean±SD age of 7.50±0.53y.The three-year cumulative incidence rate of myopia was 26.4%(207 incident cases among 784 eligible participants at baseline)in the control group and 21.2%(164 incident cases among 774 eligible participants at baseline)in the intervention group[difference of 5.2%(95%CI,3.7%to 10.1%);P=0.035].There was also a significant difference in the three-year change in spherical equivalent refraction for the control group(-0.81 D)compared with the intervention group[-0.63 D;difference of 0.18 D(95%CI,0.08 to 0.28 D);P<0.001].Elongation of axial length was significantly different between in the control group(0.77 mm)and the intervention group[0.72 mm;difference of 0.05 mm(95%CI,0.01 to 0.09 mm);P=0.003].CONCLUSION:Artificial natural light in the classroom of primary schools can result in reducing incidence rate of myopia during a period of three years.展开更多
A winter optical experiment by an artificial lamp was conducted in the Amundsen Bay of Arctic Ocean from November of 2007 to January of 2008. The radiation field emitted from an artificial lamp was measured and is int...A winter optical experiment by an artificial lamp was conducted in the Amundsen Bay of Arctic Ocean from November of 2007 to January of 2008. The radiation field emitted from an artificial lamp was measured and is introduced in this paper, and the optimized experiment project is discussed. It is demonstrated that the minimum size allowed of the lamp is determined by both the field of view （ FOV ） of optical instrument and the measuring distance from the lamp. Some problems that might influence on the experiment result often occur for a simple fluorescent lamp, such as instability, spatial nonuniformity, light divergence, effect of lamp temperature, etc. By the analysis of the light radiation, three kind of measures are proposed to control the quality of the experiment, i.e. keeping consistency of lamp size with FOV of instrument, calibrating in situ downwind, and conducting measurement in effective range. Among them, the downwind calibration is the key step to overcome most problems arose by the lamp. The experiment indicated that the reliable results can be obtained only when the optical measurement is coordinated with the radiation field of artificial lamp. The measured radiation property of the lamp was used to advise the field experiment to minimize measuring error. As the experiment by artificial lamp was the first attempt in the Arctic Ocean, the experience given by this paper is a valuable reference to the correlative studies.展开更多
In agriculture,LED light sources have increasingly replaced the standard luminescent lamps and have acquired an important role in plant micropropagation.We studied the effect of different light sources such as narrow-...In agriculture,LED light sources have increasingly replaced the standard luminescent lamps and have acquired an important role in plant micropropagation.We studied the effect of different light sources such as narrow-band LEDs(bright blue,blue,green,yellow,deep red,and red)and wide-band LEDs(cold white,white,warm white,full spectrum,and an artificial solar spectrum sun box constructed by us)on development of potato plantlets in vitro.White luminescent lamps were used as a control.The light intensity of 49μmol·m^(-2)·s^(-1)was provided in all light treatments.We showed that the long-wave narrow-band light treatments were inapplicable for potato micropropagation,because plantlets were weak with small leaves,inhibited roots,and significantly elongated stems.Blue lights provided growth of shortened plantlets with large leaves,well-growing roots,and abundant green mass.The chlorophyll content was lower under blue and bright blue light and was at the same level in the remained treatments.Significant differences in the stomatal apparatus development were observed depending on the light source.These differences were not always reflected in the plantlet phenotype:e.g.,plantlets under blue and bright blue lights showed no differences in any characteristics except stomatal density and size of stomatal guard cells.We found no significant effect of blue light portion in the white lights and full spectrum on plantlet growth.An artificial solar spectrum sun box was the most suitable for potato micropropagation,because it supported the development of plantlets with good fitness,uniform internodes length,abundant roots and green mass accumulation.展开更多
Investigations about laying hens reactions on artificial light conditions were carried out in a climate chamber equipped with a floor housing system for laying hens. The release of moisture increased during light peri...Investigations about laying hens reactions on artificial light conditions were carried out in a climate chamber equipped with a floor housing system for laying hens. The release of moisture increased during light periods probably due to increased activity which increased respiration rate but also on increased scratching which increased evaporation of moisture from bedding material. The daily average was 6.29 g henl h＂l at 4 lux and 5.97 g henl hl, at 93 lux which corresponds to a difference of 5%. The level of light intensity seemed to have little influence on the release of moisture. The total release of heat was slightly higher during light periods compared to dark periods. Explanations can be increased activity but also feed intake increasing the metabolic rate during light periods. The daily average of total heat production was 17.0 W per hen at 4 lux and 14.7 at 93 lux which corresponds to a difference of 16%. The release of carbon dioxide increased during light periods probably due to increased activity and respiration.展开更多
In a commercialized, fully artificial plant factory, artificial luminaire is arranged in a unified way using a general illumination theory, an actual measurement, or an empirical methodology. However, with these metho...In a commercialized, fully artificial plant factory, artificial luminaire is arranged in a unified way using a general illumination theory, an actual measurement, or an empirical methodology. However, with these methods, lightings are implemented without considering specific optical characteristics of lighting or material characteristics of each component that constructs a cultivation system, resulting in an amount of light that becomes irregular. The amount of lighting is closely related with the growth and quality of crops, and the deviation between points where cultivated crops are located causes quality difference in the produced crops, thus impairing the economic feasibility of a plant factory. In this regard, a simulation to figure out an optimum lighting layout was performed. Arrangements based on the spectrum distribution of light source and reflector materials were implemented to ascertain the distance between lighting and height of lighting and gather information in the pre-treatment process to improve the uniformity of light in the plant cultivation system. Improvement of around 15% in light uniformity is achieved compared with the existing system after the simulation is carried out. This result would reduce the deviation in crop growth to make uniform quality crop production possible.展开更多
Artificial light at night (ALAN) is an emerging component of global change and may increase the risk of plant invasion.However,the effects of different intensities of ALAN on the growth of invasive and native plants r...Artificial light at night (ALAN) is an emerging component of global change and may increase the risk of plant invasion.However,the effects of different intensities of ALAN on the growth of invasive and native plants remain unclear.We conducted a controlled experiment in which five pairs of invasive and native plants from different families were grown separately under three light regimes: ambient light,low ALAN,and high ALAN.Our study showed that the total biomass of both invasive and native plants increased significantly under low-intensity ALAN.However,under high-intensity ALAN,the total biomass of invasive plants increased significantly,whereas the biomass of native plants significantly decreased.These findings indicate that invasive plants can better utilize light energy and have more effective photosynthetic responses under ALAN,while the photosynthesis of native plants is inhibited.The leaf dry matter content and leaf nitrogen content of invasive plants were significantly higher than those of native plants under ALAN,which significantly improved the photosynthetic nitrogen use efficiency of invasive plants.This indicates that invasive plants have stronger phenotypic plasticity and nitrogen-distribution strategy under ALAN.In summary,the enhanced physiological response of invasive plants under different intensities of ALAN may contribute to their continued spread and dominance in the ecosystem.展开更多
Urbanization-induced warming has advanced the timing of spring budburst,with significant implications for urban ecosystems.However,how urban artificial light affects the spring budburst and its spatial variation withi...Urbanization-induced warming has advanced the timing of spring budburst,with significant implications for urban ecosystems.However,how urban artificial light affects the spring budburst and its spatial variation within species distribution remain underexplored,especially lacking experimental evidences.Here,we conducted a climate-controlled experiment using twigs collected conditions with and without artificial light(AL and NoAL,respectively)across three latitudinal gradients(Lhigh,Lmiddle and Llow)in China.In this study,we quantified the temperature responsiveness of spring budburst(Tres),defined as the number of days to budburst after twigs were placed in growth chambers,with a smaller value indicating stronger responsiveness.Results showed that NoAL individuals had significantly higher temperature responsiveness(54.3 days)than AL individuals(60.7 days).Additionally,AL twigs exhibited greater photoperiod limitation(12.7 days vs.7.6 days)and higher heat requirement(732.15 K vs.679.15 K)than NoAL twigs,suggesting adaptation to longer photoperiods and elevated thermal thresholds for budburst in AL-exposed individuals.More importantly,Tres difference between AL and NoAL individuals was more pronounced at higher latitudes(5.8 days at Lhigh,12.2 days at Lmiddle)than at lower latitudes(0.7 days at Llow),possibly due to higher inter-annual temperature variability in northern regions.Our findings provide experimental evidence of artificial light effects on tree phenology and highlight the importance of considering urban tree adaptability when assessing phenological responses to climate change in urban environments.展开更多
Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates gen...Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates generates resistant populations of the mosquito, therefore, new control methods must be investigated. The joint action of the population and guidelines for preventing the reproduction of the mosquito associated with the use of photoactivatable insecticides can be the alternative for the control of epidemiological outbreaks in affected regions. In this study, the photo-larvicidal activity of Photogem^（PG）, a derivative of hematoporphyrin, was investigated against 2nd-early 3rd instar of Aedes aegypti larvae （Diptera： Culicidae） under different lighting conditions （artificial lighting system and sunlight）. The dynamics of PG accumulation was characterized by CLSM （confocal laser scanning microscopy） and total time PG eliminationin solution was investigated by ultraviolet-visible spectrophotometry. The maximum photo-activity of PG was observed in 0.5 h under sunlight exposure which achieved 100% larval mortality. Fluorescence images showed a uniform distribution of PG along the digestive tract. PG remained stable in the sunlight for 48 h and in an artificial lighting system for longer periods, therefore, it can be used for the control ofAedes aegypti larvae as a new alternative to chemical insecticides. The method is considered environmentally friendly due to its rapid degradation in the presence of light. Further studies are required, so that the potential of the technique can be explored in real breeding places.展开更多
Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using...Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.展开更多
Background The timing of behavior and habitat use of nocturnal animals can be influenced by the lunar cycle in nature.The prevalence of artificial light at night(ALAN)has been recognized as a source of environmental p...Background The timing of behavior and habitat use of nocturnal animals can be influenced by the lunar cycle in nature.The prevalence of artificial light at night(ALAN)has been recognized as a source of environmental pol-lution.The interaction between ALAN and the lunar cycle on bat behavior is important for understanding anthro-pogenic effects on bats.We utilized a decade(2012–2022)of acoustic monitoring data collected in North Carolina,United States,to investigate the relationship between bat activity,lunar cycle,and light pollution.We examined whether the amount of lunar illumination affected species-specific nightly activity and whether hourly bat activity patterns varied between nights with different moon phases.We further investigated if the relationship between bat activity and the lunar cycle might be altered by light pollution.Results We found that seven bat species showed activity variation across nights in relation to the amount of moon illumination when ALAN was absent.In general,bats were less active on full moon nights compared to new moon nights.Light pollution interacted with the bat–lunar relationship in five of the seven species,masking the effect of the lunar cycle.We identified delayed bat activity patterns on nights with a full or waxing moon in seven species,and light pollution altered that pattern in four species.Overall,ALAN was associated with decreased bat activity inde-pendent of lunar cycle effects.Conclusions Our study demonstrated that at a broad spatial scale,ALAN negatively affected many North American temperate bat species and altered their lunar chronobiology.As light pollution is spreading to historically dark areas and habitats,ALAN might couple with other threats,such as the white-nose syndrome or climate change,to cause cascading damage in the environment that depends on ecosystem services such as pest control provided by bats.We argue that further research and conservation actions are needed to mitigate the impact of light pollution.展开更多
The attenuation of lateral propagating light （LPL） in sea ice was measured using an artificial light source in the Canadian Arctic during the 2007/2008 winter. The apparent attenuation coefficientμ（λ）for lateral...The attenuation of lateral propagating light （LPL） in sea ice was measured using an artificial light source in the Canadian Arctic during the 2007/2008 winter. The apparent attenuation coefficientμ（λ）for lateral prop-agating light was obtained from the measured logarithmic relative variation rate. In this study an analytical solution based on the strict optical theories is developed to validate the measured result. There is a good consistency between theoretical solution and measured data, by which a quite simple but very rigorous relationship among the light source, measurement geometry, and measured irradiance is established. The attenuation coefficients acquired by measurement and theory are the diffusion attenuation as an apparent optical property of ice, independent of the light source and shining condition. The attenuation ability of sea ice should be caused by the microstructure of sea ice, such as crystal size, ice density, brine volume, air inclusion, etc. It also includes the leak from both interfaces by directional scattering. It is verified that the measuring approach is operational and accurate to measure the attenuation of the LPL. The solution from this study did not tell the connection among the extinction and the inclusions of sea ice theoretically be-cause of insufficient understanding.展开更多
Artificial light at night has been considered an emerging threat to global biodiversity.However,the impacts of artificial light on foraging behavior in most wild animals remain largely unclear.Here,we aimed to assess ...Artificial light at night has been considered an emerging threat to global biodiversity.However,the impacts of artificial light on foraging behavior in most wild animals remain largely unclear.Here,we aimed to assess whether artificial light affects foraging behavior in Asian parti-colored bats(Vespertilio sinensis).We manipulated the spectra of light-emitting diode(LED)lighting in a laboratory.Using video and audio recording,we monitored foraging onset,total foraging time,food consumption,freezing behavior(temporary cessation of body movement),and echolocation vocalizations in triads of bats under each lighting condition.Analyses showed that the foraging activities of experimental bats were reduced under LED light.Green,yellow,and red light had greater negative effects on bats’foraging onset,total foraging time,and food consumption than white and blue light.LED light of different spectra induced increased freezing time and echolocation vocalizations in captive bats,except for the white light.The peak wavelength of light emission correlated positively with freezing time,estimated echolocation pulse rate(the number of echolocation pulses per minute),and foraging onset,but negatively with total foraging time and food consumption.These results demonstrate that artificial light disturbs foraging behavior in Asian parti-colored bats.Our findings have implications for understanding the influencing mechanism of light pollution on bat foraging.展开更多
The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters.This is especially the case for large compact urban areas in which the density and shadow from ...The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters.This is especially the case for large compact urban areas in which the density and shadow from neighboring buildings can limit the accessible daylighting in indoor spaces.This paper investigates the satisfaction range for illuminance regarding indoor air temperature in office buildings and the significant parameters affecting this range in six office buildings in Tehran,Iran.Lighting comfort has been evaluated by a subjective survey(509 total responses)and field measurement.The questionnaires were filled out in 146 and 109 rooms in summer and winter,respectively.The results show that the illuminance should not be less than 550 lx,while illuminance between 600 and 650 lx provides the highest satisfaction level.The satisfaction with lighting level is affected by individual parameters such as age,type of activity,and environmental parameters such as window orientation,external obscurations,and season.A relationship was observed between lighting level satisfaction and thermal condition acceptance,and the overall comfort depends more on thermal conditions than the lighting level.展开更多
Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are res...Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are restricting the wide application of this technology.In order to design an optimal artificial lighting environment for lettuce production,effects of different combinations of light intensity,photoperiod,and light quality on growth,quality,photosynthesis,and energy use efficiency of lettuce(Lactuca sativa L.cv Ziwei)were investigated under a closed plant factory.Lettuce transplants were grown under photosynthetic photon flux density(PPFD)at 150μmol/m^(2)·s,200μmol/m^(2)·s,250μmol/m^(2)·s,and 300μmol/m^(2)·s provided by fluorescent lamps(FL)with a red to blue ratio(R:B ratio)of 1.8 and light-emitting diode(LED)lamps with R:B ratio of 1.2 and 2.2,in combination with photoperiod of 12 and 16 h/d.In order to examine the“long term”photosynthetic characteristics,net photosynthetic rates of hydroponic lettuce leaves were continuously measured for 2 d(15^(th) and 16^(th) day after transplanting)before harvest.There was no difference in leaf fresh weight(FW)between PPFD of 250μmol/m^(2)·s and 300μmol/m^(2)·s with photoperiod of 16 h/d,regardless of light quality,and same results showed in contents of nitrate,soluble sugar,and vitamin C,respectively.The results of continuous measurements of net photosynthetic rate of lettuce leaves before harvest indicated that plants grown at PPFD of 250μmol/m^(2)·s had consistently higher compared to those grown at PPFD of 300μmol/m^(2)·s.Combining the results from growth,photosynthesis,quality,and energy consumption,it can be concluded that PPFD at 250μmol/m^(2)·s with photoperiod of 16 h/d under LED with R:B ratio of 2.2 is a suitable light environment for maximum growth and high quality of commercial lettuce(cv.Ziwei)production under indoor controlled environment.展开更多
Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in thi...Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in this Letter, and a trained neural network is used to achieve positioning with a diffuse channel. Simulations are made to evaluate the proposed positioning algorithm. Results show that the average positioning error is reduced about 13 times, and the positioning time is reduced about two magnitudes. Moreover, the proposed algorithm is robust with a different field-of-view of the receiver and the refiectivity of the wall, which is suitable for various position- ing applications.展开更多
Objective:To compare different artificial light sources in different places where plant breeding is conduced.Methods:Measurements were conducted outdoor,in room,in greenhouse,under four panels with light emitting diod...Objective:To compare different artificial light sources in different places where plant breeding is conduced.Methods:Measurements were conducted outdoor,in room,in greenhouse,under four panels with light emitting diodes,in phytotron,in dark room with various light sources and inside Sanyo versatile environmental chamber.The measurements were made by using SpectraPen SP100(PSI,Czech Republic)device.Results:Our result showed that spectrum measured outdoor during sunny day had only one peak at the wavelength of 485 nm(ca.60000 relative units).On cloudy day,the trend of light spectrum curve was similar,but with lower values.At room conditions,the curve was more flat than outdoor.Under greenhouse conditions,the curve was similar to that measured outdoor.A few additional peaks on the curve appeared by adding high pressure sodium lamp.There were changes of curve under LED panels.Conclusions:It must be underlined that the most similar spectrum curve to daylight light has incandescent bulb and this light source should be preferred as support of daylight in greenhouses and as main source in phytotrons.Using high pressure sodium lamp in greenhouses as support of daylight cause increase in the red/far-red ratio and occurrence of a new peak on spectrum curve.The new possibilities are creating by LED panels with red and blue diodes.展开更多
Though mesopelagic fish respond to natural light(e.g.,diurnal vertical migration),few studies have looked at how they respond to artificial light and if artificial lights could be used in commercial operations to impr...Though mesopelagic fish respond to natural light(e.g.,diurnal vertical migration),few studies have looked at how they respond to artificial light and if artificial lights could be used in commercial operations to improve catchability of mesopelagic fish.Here we present a preliminary study on how mesopelagic organisms respond to blue and green spotlights,as well as red and white diffuse lights in Masfjorden(Norway;max depth of 480 m).The response of organisms in each of the three sound scattering layers(SSLs)was observed when a)artificial lights were positioned in a layer or b)moved with a constant speed(generally 0.03 ms1)towards a layer.The artificial lights were attached to a rig with a self-contained echosounder,which recorded the vertical and horizontal avoidance of organisms in each SSL to different artificial lights.Net hauls(MIC-net)and video footage confirmed that Maurolicus muelleri and siphonophores were present in the upper layer(100-150 m),while Benthosema glaciale were present in the deeper layers(~200 m and~300 m to seabed).Our findings suggest that M.muelleri(SSL1)horizontally avoid blue spotlight and white diffuse light,while B.glaciale(SSL2 and SSL3)mainly avoid the same lights downwards and can be herded downwards over 250 m.Though this study should be regarded as preliminary,the observed avoidance/herding response suggests artificial lights could be applied to improve existing fish capture methods for mesopelagic fish.展开更多
Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plan...Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.展开更多
基金funded by the Doctor Foundation of Southwest University of Science and Technology,grant number:24zx7116.
文摘Supplemental lighting has emerged as a widely adopted technique in greenhouse cultivation to enhance product visibility andimprove theflavor characteristics ofChinese bayberry(Myrica rubra)in the internationalmarket.While studies on lighting have predominantly focused on colorimetry,limited research has addressed the precise control of chromatic parameters and their effect on fruit quality.This study examined the effects of varying lighting conditions,specifically correlated color temperatures and illuminance,on the growth and quality of Chinese bayberry varieties“Black Charcoal”and“Dongkui”using a precision control system.The bayberry plants were exposed to a constant illuminance of 155μmol·m^(-2)·s^(-1) with chromatic levels ranging from 2250 to 6000 K.Black Charcoal demonstrated substantial improvements under different chromatic parameters,with fruit weight and size increasing by 40%and 14%,respectively.Furthermore,soluble solids content increased by 4% and vitamin C content rose by 142%,while organic acid content decreased by 30%.Dongkui,however,showed more modest responses under identical conditions,with fruit weight increasing by 2% and fruit size decreasing by 1%.Soluble solids and vitamin C contents showed minimal increases of 2% and 2.5%,respectively,while organic acid content decreased by 8%.The findings demonstrate that supplemental LED lighting significantly enhances both yield and quality parameters in Black Charcoal compared with Dongkui.These results provide valuable insights for optimizing Chinese bayberry cultivation,and the precise control methodology developed can be used to improve supplemental lighting strategies in other fruit and plant species.
文摘The challenges and opportunities for developing sustainable plant factories with artificial lighting(PFALs)are discussed.After examining the production cost and productivity of existing PFALs in Japan,the possibility of introducing a relatively new concept and methodology for considerably improving productivity are discussed in relation to environmental controllability and resource use efficiencies.The fundamental and potential characteristics of ideal or next-generation PFALs(n-PFALs)are then discussed with some suggestions for actualizing n-PFALs.Finally,perspectives of the n-PFALs and technologies to be integrated into the n-PFALs are presented in relation to the Sustainable Development Goals(SDGs)to be achieved by 2030.
基金Guangdong Basic and Applied Basic Research Foundation(No.2019B1515120011)Medical Research,Foshan Health and Wellness Department(No.20220374).
文摘AIM:To assess the efficacy of artificial natural light in preventing incident myopia in primary school-age children.METHODS:This is a prospective,randomized control,intervention study.A total of 1840 students from 39 classes in 4 primary schools in Foshan participated in this study.The whole randomization method was adopted to include classes as a group according to 1:1 randomized control.Classrooms in the control group were illuminated by usual light,and classrooms in the intervention group were illuminated by artificial natural light.All students received uncorrected visual acuity and best-corrected visual acuity measurement,non-cycloplegic autorefraction,ocular biometric examination,slit lamp and strabismus examination.Three-year follow-up,the students underwent same procedures.Myopia was defined as spherical equivalent refraction≤-0.50 D and uncorrected visual acuity<20/20.RESULTS:There were 894 students in the control group and 946 students in the intervention group with a mean±SD age of 7.50±0.53y.The three-year cumulative incidence rate of myopia was 26.4%(207 incident cases among 784 eligible participants at baseline)in the control group and 21.2%(164 incident cases among 774 eligible participants at baseline)in the intervention group[difference of 5.2%(95%CI,3.7%to 10.1%);P=0.035].There was also a significant difference in the three-year change in spherical equivalent refraction for the control group(-0.81 D)compared with the intervention group[-0.63 D;difference of 0.18 D(95%CI,0.08 to 0.28 D);P<0.001].Elongation of axial length was significantly different between in the control group(0.77 mm)and the intervention group[0.72 mm;difference of 0.05 mm(95%CI,0.01 to 0.09 mm);P=0.003].CONCLUSION:Artificial natural light in the classroom of primary schools can result in reducing incidence rate of myopia during a period of three years.
基金supported by the Nature Science Foundation of China (No.40631006) and the International Polar Year Program of ChinaThe field experiment was supported by the Canadian International Polar Year(IPY) program,the CircumpolarFlaw Lead(CFL) System Study.
文摘A winter optical experiment by an artificial lamp was conducted in the Amundsen Bay of Arctic Ocean from November of 2007 to January of 2008. The radiation field emitted from an artificial lamp was measured and is introduced in this paper, and the optimized experiment project is discussed. It is demonstrated that the minimum size allowed of the lamp is determined by both the field of view （ FOV ） of optical instrument and the measuring distance from the lamp. Some problems that might influence on the experiment result often occur for a simple fluorescent lamp, such as instability, spatial nonuniformity, light divergence, effect of lamp temperature, etc. By the analysis of the light radiation, three kind of measures are proposed to control the quality of the experiment, i.e. keeping consistency of lamp size with FOV of instrument, calibrating in situ downwind, and conducting measurement in effective range. Among them, the downwind calibration is the key step to overcome most problems arose by the lamp. The experiment indicated that the reliable results can be obtained only when the optical measurement is coordinated with the radiation field of artificial lamp. The measured radiation property of the lamp was used to advise the field experiment to minimize measuring error. As the experiment by artificial lamp was the first attempt in the Arctic Ocean, the experience given by this paper is a valuable reference to the correlative studies.
基金financially supported by the Russian Science Foundation(Grant No.20-16-00016)。
文摘In agriculture,LED light sources have increasingly replaced the standard luminescent lamps and have acquired an important role in plant micropropagation.We studied the effect of different light sources such as narrow-band LEDs(bright blue,blue,green,yellow,deep red,and red)and wide-band LEDs(cold white,white,warm white,full spectrum,and an artificial solar spectrum sun box constructed by us)on development of potato plantlets in vitro.White luminescent lamps were used as a control.The light intensity of 49μmol·m^(-2)·s^(-1)was provided in all light treatments.We showed that the long-wave narrow-band light treatments were inapplicable for potato micropropagation,because plantlets were weak with small leaves,inhibited roots,and significantly elongated stems.Blue lights provided growth of shortened plantlets with large leaves,well-growing roots,and abundant green mass.The chlorophyll content was lower under blue and bright blue light and was at the same level in the remained treatments.Significant differences in the stomatal apparatus development were observed depending on the light source.These differences were not always reflected in the plantlet phenotype:e.g.,plantlets under blue and bright blue lights showed no differences in any characteristics except stomatal density and size of stomatal guard cells.We found no significant effect of blue light portion in the white lights and full spectrum on plantlet growth.An artificial solar spectrum sun box was the most suitable for potato micropropagation,because it supported the development of plantlets with good fitness,uniform internodes length,abundant roots and green mass accumulation.
文摘Investigations about laying hens reactions on artificial light conditions were carried out in a climate chamber equipped with a floor housing system for laying hens. The release of moisture increased during light periods probably due to increased activity which increased respiration rate but also on increased scratching which increased evaporation of moisture from bedding material. The daily average was 6.29 g henl h＂l at 4 lux and 5.97 g henl hl, at 93 lux which corresponds to a difference of 5%. The level of light intensity seemed to have little influence on the release of moisture. The total release of heat was slightly higher during light periods compared to dark periods. Explanations can be increased activity but also feed intake increasing the metabolic rate during light periods. The daily average of total heat production was 17.0 W per hen at 4 lux and 14.7 at 93 lux which corresponds to a difference of 16%. The release of carbon dioxide increased during light periods probably due to increased activity and respiration.
基金financially supported by the Ministry of Education, Science, and Technology (MEST)the National Research Foundation of Korea (NRF) through the Human Resource Training Project for Regional Innovationsupported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (No.20114010203040) grant funded by the Korean government’s Ministry of Knowledge Economy
文摘In a commercialized, fully artificial plant factory, artificial luminaire is arranged in a unified way using a general illumination theory, an actual measurement, or an empirical methodology. However, with these methods, lightings are implemented without considering specific optical characteristics of lighting or material characteristics of each component that constructs a cultivation system, resulting in an amount of light that becomes irregular. The amount of lighting is closely related with the growth and quality of crops, and the deviation between points where cultivated crops are located causes quality difference in the produced crops, thus impairing the economic feasibility of a plant factory. In this regard, a simulation to figure out an optimum lighting layout was performed. Arrangements based on the spectrum distribution of light source and reflector materials were implemented to ascertain the distance between lighting and height of lighting and gather information in the pre-treatment process to improve the uniformity of light in the plant cultivation system. Improvement of around 15% in light uniformity is achieved compared with the existing system after the simulation is carried out. This result would reduce the deviation in crop growth to make uniform quality crop production possible.
基金supported by the National Natural Science Foundation of China (grant no. 31772235)the State Key Laboratory of Vegetation and Environmental Change (grant no. LVEC-2022kf01)。
文摘Artificial light at night (ALAN) is an emerging component of global change and may increase the risk of plant invasion.However,the effects of different intensities of ALAN on the growth of invasive and native plants remain unclear.We conducted a controlled experiment in which five pairs of invasive and native plants from different families were grown separately under three light regimes: ambient light,low ALAN,and high ALAN.Our study showed that the total biomass of both invasive and native plants increased significantly under low-intensity ALAN.However,under high-intensity ALAN,the total biomass of invasive plants increased significantly,whereas the biomass of native plants significantly decreased.These findings indicate that invasive plants can better utilize light energy and have more effective photosynthetic responses under ALAN,while the photosynthesis of native plants is inhibited.The leaf dry matter content and leaf nitrogen content of invasive plants were significantly higher than those of native plants under ALAN,which significantly improved the photosynthetic nitrogen use efficiency of invasive plants.This indicates that invasive plants have stronger phenotypic plasticity and nitrogen-distribution strategy under ALAN.In summary,the enhanced physiological response of invasive plants under different intensities of ALAN may contribute to their continued spread and dominance in the ecosystem.
基金supported by the International Cooperation and Exchange of the National Natural Science Foundation of China-FAPESP Program(Grant no.42261144755)the National Key Research and Development Program(2023YFF0805604)+1 种基金the Fundamental Research Funds for the Central Universities(no.2243300004)Z.W.was funded by the China Scholarship Council(no.202206040112).
文摘Urbanization-induced warming has advanced the timing of spring budburst,with significant implications for urban ecosystems.However,how urban artificial light affects the spring budburst and its spatial variation within species distribution remain underexplored,especially lacking experimental evidences.Here,we conducted a climate-controlled experiment using twigs collected conditions with and without artificial light(AL and NoAL,respectively)across three latitudinal gradients(Lhigh,Lmiddle and Llow)in China.In this study,we quantified the temperature responsiveness of spring budburst(Tres),defined as the number of days to budburst after twigs were placed in growth chambers,with a smaller value indicating stronger responsiveness.Results showed that NoAL individuals had significantly higher temperature responsiveness(54.3 days)than AL individuals(60.7 days).Additionally,AL twigs exhibited greater photoperiod limitation(12.7 days vs.7.6 days)and higher heat requirement(732.15 K vs.679.15 K)than NoAL twigs,suggesting adaptation to longer photoperiods and elevated thermal thresholds for budburst in AL-exposed individuals.More importantly,Tres difference between AL and NoAL individuals was more pronounced at higher latitudes(5.8 days at Lhigh,12.2 days at Lmiddle)than at lower latitudes(0.7 days at Llow),possibly due to higher inter-annual temperature variability in northern regions.Our findings provide experimental evidence of artificial light effects on tree phenology and highlight the importance of considering urban tree adaptability when assessing phenological responses to climate change in urban environments.
文摘Dengue vector is responsible for millions of deaths every year and has caused disastrous impacts on health systems. The continuous use of chemical insecticides, such as carbamates, pyrethroids and organophosphates generates resistant populations of the mosquito, therefore, new control methods must be investigated. The joint action of the population and guidelines for preventing the reproduction of the mosquito associated with the use of photoactivatable insecticides can be the alternative for the control of epidemiological outbreaks in affected regions. In this study, the photo-larvicidal activity of Photogem^（PG）, a derivative of hematoporphyrin, was investigated against 2nd-early 3rd instar of Aedes aegypti larvae （Diptera： Culicidae） under different lighting conditions （artificial lighting system and sunlight）. The dynamics of PG accumulation was characterized by CLSM （confocal laser scanning microscopy） and total time PG eliminationin solution was investigated by ultraviolet-visible spectrophotometry. The maximum photo-activity of PG was observed in 0.5 h under sunlight exposure which achieved 100% larval mortality. Fluorescence images showed a uniform distribution of PG along the digestive tract. PG remained stable in the sunlight for 48 h and in an artificial lighting system for longer periods, therefore, it can be used for the control ofAedes aegypti larvae as a new alternative to chemical insecticides. The method is considered environmentally friendly due to its rapid degradation in the presence of light. Further studies are required, so that the potential of the technique can be explored in real breeding places.
基金Supported by the National Key Technologies R&D Program of China(No.2011BAD13B04)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q212)+2 种基金the Public Service Sectors(Agriculture)Special Project(No.201003024)the Earmarked Fund for Modern Agro-Industry Technology Research Systemthe Shandong Program for Development of Science and Technology(No.2013GHY11514)
文摘Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.
基金support of the United States Fish and Wildlife Servicethe North Carolina Wildlife Resources Commission+1 种基金the University of North Carolina GreensboroSoutheastern Bat Diversity Network
文摘Background The timing of behavior and habitat use of nocturnal animals can be influenced by the lunar cycle in nature.The prevalence of artificial light at night(ALAN)has been recognized as a source of environmental pol-lution.The interaction between ALAN and the lunar cycle on bat behavior is important for understanding anthro-pogenic effects on bats.We utilized a decade(2012–2022)of acoustic monitoring data collected in North Carolina,United States,to investigate the relationship between bat activity,lunar cycle,and light pollution.We examined whether the amount of lunar illumination affected species-specific nightly activity and whether hourly bat activity patterns varied between nights with different moon phases.We further investigated if the relationship between bat activity and the lunar cycle might be altered by light pollution.Results We found that seven bat species showed activity variation across nights in relation to the amount of moon illumination when ALAN was absent.In general,bats were less active on full moon nights compared to new moon nights.Light pollution interacted with the bat–lunar relationship in five of the seven species,masking the effect of the lunar cycle.We identified delayed bat activity patterns on nights with a full or waxing moon in seven species,and light pollution altered that pattern in four species.Overall,ALAN was associated with decreased bat activity inde-pendent of lunar cycle effects.Conclusions Our study demonstrated that at a broad spatial scale,ALAN negatively affected many North American temperate bat species and altered their lunar chronobiology.As light pollution is spreading to historically dark areas and habitats,ALAN might couple with other threats,such as the white-nose syndrome or climate change,to cause cascading damage in the environment that depends on ecosystem services such as pest control provided by bats.We argue that further research and conservation actions are needed to mitigate the impact of light pollution.
基金The Global Change Research Program of China under contract No.2015CB953900the Key Program of National Natural Science Foundation of China under contract No.41330960
文摘The attenuation of lateral propagating light （LPL） in sea ice was measured using an artificial light source in the Canadian Arctic during the 2007/2008 winter. The apparent attenuation coefficientμ（λ）for lateral prop-agating light was obtained from the measured logarithmic relative variation rate. In this study an analytical solution based on the strict optical theories is developed to validate the measured result. There is a good consistency between theoretical solution and measured data, by which a quite simple but very rigorous relationship among the light source, measurement geometry, and measured irradiance is established. The attenuation coefficients acquired by measurement and theory are the diffusion attenuation as an apparent optical property of ice, independent of the light source and shining condition. The attenuation ability of sea ice should be caused by the microstructure of sea ice, such as crystal size, ice density, brine volume, air inclusion, etc. It also includes the leak from both interfaces by directional scattering. It is verified that the measuring approach is operational and accurate to measure the attenuation of the LPL. The solution from this study did not tell the connection among the extinction and the inclusions of sea ice theoretically be-cause of insufficient understanding.
基金supported by the National Natural Science Foundation of China(Grant Nos.32271561 and 32071492)the Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC1761)the Undergraduate Innovation and Entrepreneurship Training Program of China(Grant Nos.S202210638071 and 202310638011).
文摘Artificial light at night has been considered an emerging threat to global biodiversity.However,the impacts of artificial light on foraging behavior in most wild animals remain largely unclear.Here,we aimed to assess whether artificial light affects foraging behavior in Asian parti-colored bats(Vespertilio sinensis).We manipulated the spectra of light-emitting diode(LED)lighting in a laboratory.Using video and audio recording,we monitored foraging onset,total foraging time,food consumption,freezing behavior(temporary cessation of body movement),and echolocation vocalizations in triads of bats under each lighting condition.Analyses showed that the foraging activities of experimental bats were reduced under LED light.Green,yellow,and red light had greater negative effects on bats’foraging onset,total foraging time,and food consumption than white and blue light.LED light of different spectra induced increased freezing time and echolocation vocalizations in captive bats,except for the white light.The peak wavelength of light emission correlated positively with freezing time,estimated echolocation pulse rate(the number of echolocation pulses per minute),and foraging onset,but negatively with total foraging time and food consumption.These results demonstrate that artificial light disturbs foraging behavior in Asian parti-colored bats.Our findings have implications for understanding the influencing mechanism of light pollution on bat foraging.
文摘The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters.This is especially the case for large compact urban areas in which the density and shadow from neighboring buildings can limit the accessible daylighting in indoor spaces.This paper investigates the satisfaction range for illuminance regarding indoor air temperature in office buildings and the significant parameters affecting this range in six office buildings in Tehran,Iran.Lighting comfort has been evaluated by a subjective survey(509 total responses)and field measurement.The questionnaires were filled out in 146 and 109 rooms in summer and winter,respectively.The results show that the illuminance should not be less than 550 lx,while illuminance between 600 and 650 lx provides the highest satisfaction level.The satisfaction with lighting level is affected by individual parameters such as age,type of activity,and environmental parameters such as window orientation,external obscurations,and season.A relationship was observed between lighting level satisfaction and thermal condition acceptance,and the overall comfort depends more on thermal conditions than the lighting level.
基金supported by the National High Technology Research and Development Program(“863”Program)of China(2013AA103005).
文摘Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are restricting the wide application of this technology.In order to design an optimal artificial lighting environment for lettuce production,effects of different combinations of light intensity,photoperiod,and light quality on growth,quality,photosynthesis,and energy use efficiency of lettuce(Lactuca sativa L.cv Ziwei)were investigated under a closed plant factory.Lettuce transplants were grown under photosynthetic photon flux density(PPFD)at 150μmol/m^(2)·s,200μmol/m^(2)·s,250μmol/m^(2)·s,and 300μmol/m^(2)·s provided by fluorescent lamps(FL)with a red to blue ratio(R:B ratio)of 1.8 and light-emitting diode(LED)lamps with R:B ratio of 1.2 and 2.2,in combination with photoperiod of 12 and 16 h/d.In order to examine the“long term”photosynthetic characteristics,net photosynthetic rates of hydroponic lettuce leaves were continuously measured for 2 d(15^(th) and 16^(th) day after transplanting)before harvest.There was no difference in leaf fresh weight(FW)between PPFD of 250μmol/m^(2)·s and 300μmol/m^(2)·s with photoperiod of 16 h/d,regardless of light quality,and same results showed in contents of nitrate,soluble sugar,and vitamin C,respectively.The results of continuous measurements of net photosynthetic rate of lettuce leaves before harvest indicated that plants grown at PPFD of 250μmol/m^(2)·s had consistently higher compared to those grown at PPFD of 300μmol/m^(2)·s.Combining the results from growth,photosynthesis,quality,and energy consumption,it can be concluded that PPFD at 250μmol/m^(2)·s with photoperiod of 16 h/d under LED with R:B ratio of 2.2 is a suitable light environment for maximum growth and high quality of commercial lettuce(cv.Ziwei)production under indoor controlled environment.
基金supported by the National Natural Science Foundation of China(Nos.61475094 and61675025)the National 973 Program of China(No.2013CB329202)
文摘Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in this Letter, and a trained neural network is used to achieve positioning with a diffuse channel. Simulations are made to evaluate the proposed positioning algorithm. Results show that the average positioning error is reduced about 13 times, and the positioning time is reduced about two magnitudes. Moreover, the proposed algorithm is robust with a different field-of-view of the receiver and the refiectivity of the wall, which is suitable for various position- ing applications.
基金supported by The National Centre for Research and Development(NCBiR)Poland(Grant:Biostrateg-I/2489/2014).
文摘Objective:To compare different artificial light sources in different places where plant breeding is conduced.Methods:Measurements were conducted outdoor,in room,in greenhouse,under four panels with light emitting diodes,in phytotron,in dark room with various light sources and inside Sanyo versatile environmental chamber.The measurements were made by using SpectraPen SP100(PSI,Czech Republic)device.Results:Our result showed that spectrum measured outdoor during sunny day had only one peak at the wavelength of 485 nm(ca.60000 relative units).On cloudy day,the trend of light spectrum curve was similar,but with lower values.At room conditions,the curve was more flat than outdoor.Under greenhouse conditions,the curve was similar to that measured outdoor.A few additional peaks on the curve appeared by adding high pressure sodium lamp.There were changes of curve under LED panels.Conclusions:It must be underlined that the most similar spectrum curve to daylight light has incandescent bulb and this light source should be preferred as support of daylight in greenhouses and as main source in phytotrons.Using high pressure sodium lamp in greenhouses as support of daylight cause increase in the red/far-red ratio and occurrence of a new peak on spectrum curve.The new possibilities are creating by LED panels with red and blue diodes.
文摘Though mesopelagic fish respond to natural light(e.g.,diurnal vertical migration),few studies have looked at how they respond to artificial light and if artificial lights could be used in commercial operations to improve catchability of mesopelagic fish.Here we present a preliminary study on how mesopelagic organisms respond to blue and green spotlights,as well as red and white diffuse lights in Masfjorden(Norway;max depth of 480 m).The response of organisms in each of the three sound scattering layers(SSLs)was observed when a)artificial lights were positioned in a layer or b)moved with a constant speed(generally 0.03 ms1)towards a layer.The artificial lights were attached to a rig with a self-contained echosounder,which recorded the vertical and horizontal avoidance of organisms in each SSL to different artificial lights.Net hauls(MIC-net)and video footage confirmed that Maurolicus muelleri and siphonophores were present in the upper layer(100-150 m),while Benthosema glaciale were present in the deeper layers(~200 m and~300 m to seabed).Our findings suggest that M.muelleri(SSL1)horizontally avoid blue spotlight and white diffuse light,while B.glaciale(SSL2 and SSL3)mainly avoid the same lights downwards and can be herded downwards over 250 m.Though this study should be regarded as preliminary,the observed avoidance/herding response suggests artificial lights could be applied to improve existing fish capture methods for mesopelagic fish.
基金This work was supported by the National Key Research and Development Program of China(2017YFB0403901)This manuscript was presented at 2019 International Symposium on Environment Control Technology for Value-added Plant Production hold in Beijing from Aug.27-29,2019.
文摘Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.
