Metal halides have attracted worldwide attention as exceptional optoelectronic materials.Over the past decade,research on metal halides has yielded remarkable progress,and their color-conversion applications have show...Metal halides have attracted worldwide attention as exceptional optoelectronic materials.Over the past decade,research on metal halides has yielded remarkable progress,and their color-conversion applications have shown considerable promise for commercialization.With the reporting of self-trapped exciton(STE)emission in perovskites,the application of metal halides as broadband emitting materials in the lighting field has gained increas-ing interest.Herein,we provide a comprehensive review of metal halide STE emitters,especially for lighting applications.We begin with highlighting the ideal spectral characteristics and corresponding performance metrics for lighting.This is followed by a systematic summary of the mechanisms,optimization strategies,and recent advances of STE emission in metal halides.Finally,we outline the major challenges and prospective trends for metal halide STE emitters.This review aims to offer valuable insights into metal halide STE emitters and their lighting applications for facilitating the future commercialization.展开更多
In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still rel...In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.展开更多
The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions a...The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions and are easy to lose detailed information.So we propose a rendered image denoising method with filtering guided by lighting information.First,we design an image segmentation algorithm based on lighting information to segment the image into different illumination areas.Then,we establish the parameter prediction model guided by lighting information for filtering(PGLF)to predict the filtering parameters of different illumination areas.For different illumination areas,we use these filtering parameters to construct area filters,and the filters are guided by the lighting information to perform sub-area filtering.Finally,the filtering results are fused with auxiliary features to output denoised images for improving the overall denoising effect of the image.Under the physically based rendering tool(PBRT)scene and Tungsten dataset,the experimental results show that compared with other guided filtering denoising methods,our method improves the peak signal-to-noise ratio(PSNR)metrics by 4.2164 dB on average and the structural similarity index(SSIM)metrics by 7.8%on average.This shows that our method can better reduce the noise in complex lighting scenesand improvethe imagequality.展开更多
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 rapid expansion of urbanization has led to widespread exposure of wild birds to intensive light at night(LAN).While previous studies have established LAN-induced cognitive impairment in birds,the underlying neurob...The rapid expansion of urbanization has led to widespread exposure of wild birds to intensive light at night(LAN).While previous studies have established LAN-induced cognitive impairment in birds,the underlying neurobiological mechanisms remain poorly understood.We hypothesized that LAN exposure impaired cognitive function of birds potentially through neurodegeneration,metabolic dysregulation and neuroinflammatory responses in the telencephalon.Using Zebra Finches(Taeniopygia guttata)as an avian model,under 16L:8D photoperiods,we compared associative learning and memory abilities and neurobiological parameters between experimental groups exposed to dim light at night(LAN)versus nocturnal darkness(CTR).Compared to the CTR birds,the LAN-exposed birds exhibited significantly lower learning and memory performances,reduced neuron density and simplified dendritic morphology in the telencephalons.The key energy metabolic substrates(cholic acid,CTP,D-mannose-6-phosphate)and neuroprotective agents(trehalose,menaquinone,L-gulono-1,4-lactone)in the telencephalons of LAN-exposed birds showed depletion,while oxidative stress markers(methionine sulfoxide)and inflammatory mediators(cis-gondoic acid)exhibited elevation.The neurotransmitter dopamine and histamine metabolic pathway were disrupted in the LAN-exposed birds.The microglias were activated with pro-inflammatory IL-1βand IL-6 levels increasing and anti-inflammatory IL-10 decreasing in the telencephalons of the LAN-exposed birds.These findings indicate a potential mechanistic pathway whereby dim light exposure at night can induce neuroinflammation through oxidative stress-mediated microglial activation,energy metabolism and neurotransmitter homeostasis disruption,ultimately leading to neurodegeneration in the telencephalons of birds.展开更多
Green space plays an important role in the sustainable urban development.This study proposes the Green Lighting Index(GLI),integrating nighttime light data from SDGSAT-1 and theNormalized DifferenceVegetation Index(ND...Green space plays an important role in the sustainable urban development.This study proposes the Green Lighting Index(GLI),integrating nighttime light data from SDGSAT-1 and theNormalized DifferenceVegetation Index(NDVI)from Sentinel-2,to explore the nighttime human activity in green spaces across three major urban agglomerations in China:Beijing-Tianjin-Hebei(BTH),the Yangtze River Delta(YRD),and the Greater Bay Area(GBA).The findings reveal that,for most green spaces,the relationship between nighttime lighting and green spaces is predominantly exclusionary.However,a synergistic relationship is observed in some vibrant green spaces characterized by abundant nighttime lighting.This synergy is evident in high GLI levels,which are strongly positively correlated with per capita Gross Domestic Product(GDP).This research underscores the importance of integrating nighttime perspectives into green space studies.We believe GLI could be used in the assessment of green space quality and contribute to the development of sustainable cities.展开更多
Currently,most conventional street lighting systems use a constant light mode throughout the entire night,fromsunset to sunrise,which results in high energy consumption and maintenance costs.Furthermore,scientific res...Currently,most conventional street lighting systems use a constant light mode throughout the entire night,fromsunset to sunrise,which results in high energy consumption and maintenance costs.Furthermore,scientific research predicts that energy consumption for street lighting will increase in the coming years due to growing demand and rising electricity prices.The dimming strategy is a current trend and a key concept in smart street lighting systems.It involves turning on the road lights only when a vehicle or pedestrian is detected;otherwise,the control system reduces the light intensity of the lamps.Power control is generally implemented using artificial intelligence algorithms such as fuzzy logic,artificial neural networks,or swarm intelligence to manage different events.In our project,the dimming strategy was utilized to reduce costs and energy consumption by at least 48%.This research proposes a standalone photovoltaic plant(SPP)to power a smart street lighting system,which can replace individual solar street lights in a small neighborhood in southwestern Algeria.This design offers advantages such as lower costs and the option to add additional loads a DC pump,a domestic power supply,or technical services to operate the photovoltaic system during the day after charging the storage batteries,especially when there is monthly energy surplus.The energy surplus analyzed in our project ranges from 804 W in January to 4 kW in June,generated by the entire PV installation.To demonstrate the feasibility and reliability of this system,we studied the implementation of the standalone photovoltaic plant,energymanagement,and economic analysis using the Particle SwarmOptimization technique under MATLAB software.展开更多
Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty ...Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty to coexisting with other multivalent activated ions(such as Eu^(3+),Tm^(3+)),which greatly hinders the formation of full spectrum.In this study,a calcium vacancy enhanced self-reduction of Ce^(4+)is realized in CaNaSb_(2)O_(6)F(CNSOF)host under air atmosphere sintering,through which Ce^(3+),Tm^(3+)and Eu^(3+)coexisting in a single-phase full spectrum phosphor was prepared.Notably,the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism.Moreover,the energy transfer kinetics among Tm^(3+),Ce^(3+)and Eu^(3+)were explored.Finally,combined with a 340 nm UV chip,a full spectrum phosphor-converted light-emitting diode(pc-LED)was fabricated,showing a broad emission range from 400 to 750 nm,Commission Internationale de I'Edairage(CIE)of(0.3485,0.3673),Ra of 92 and correlated color temperature(CCT)of 4933 K.Utilizing the variation in emission colors of this phosphor under different UV wavelengths,a dual encryption method combining point character code and fluorescent encryption technique is proposed.This work provides an effective path for Ce^(4+)self-reduction to apply in full spectrum pc-LED and information encryption.展开更多
All-inorganic reflective phosphor-in-glass film(PiGF) converter has garnered widespread attentions for high brightness laser-driven white lighting,while its poor color quality and low luminescence stability have been ...All-inorganic reflective phosphor-in-glass film(PiGF) converter has garnered widespread attentions for high brightness laser-driven white lighting,while its poor color quality and low luminescence stability have been inevitable roadblocks.Herein,the bicolor PiGF containing green-emitting Y3Al3.08Ga1.92O12:Ce3+(YAGG) and red-emitting CaAlSiN_(3):Eu^(2+)(CASN) phosphors bonded on Al2O3substrate was prepared for enabling high color quality laser-driven white lighting in reflective configuration.The bicolor PiGF has high quantum efficiency and good structure stability.By optimizing the CASN content,PiGF thickness and Al_(2)O_(3) content,the reflective bicolor PiGF based white laser diode(LD)displays good luminescence performance with a luminous flux of 451.5 lm and a luminous efficacy of142.3 lm/W and high color quality with a color rendering index(CRI) of 85.3 and a correlated color temperature(CCT) of 5177 K under the incident laser power of 3.15 W,and still has excellent luminescence and color stabilities(CRI and CCT) under the continuous laser excitation of 5.61 W,attributed to the good thermal conductivity and high reflectivity of Al_(2)O_(3) substrate and scattering enhancement effect of Al_(2)O_(3) particles.It can be foreseen that the reflective bicolor PiGF converter provides a promising strategy for enabling high quality laser-driven white lighting.展开更多
In recent years,the development of solid-state lighting devices has increasingly shifted towards high-power laser illumination,making it imperative to develop fluorescent conversion materials with exceptional thermal ...In recent years,the development of solid-state lighting devices has increasingly shifted towards high-power laser illumination,making it imperative to develop fluorescent conversion materials with exceptional thermal stability and luminous quality.In this study,we introduced a highly reflective TiO_(2) substrate in combination with a high thermal conductivity AlN substrate to design a Ce:YAG-PiG-TiO_(2)-AlN Film(Ce:YAG PTAF)color converter with outstanding photothermal performance.Remarkably,the thermal conductivity of this material reaches 48.28 W m^(-1) K^(-1).Notably,the optimized PTAF can withstand a high-power output of up to 12.14 W in a static environment,with a maximum luminous flux(LFmax)of 2284.6 lm and maximum luminous efficacy(LEmax)of 222.35 lm W^(-1),showcasing its excellent optical properties.Furthermore,the fabricated Ce:YAG-PiG-TiO_(2)-AlN-Wheel(Ce:YAG PTAW),equipped with a motor operating at 7200 r/min,emits an extraordinary brightness of 4404 lm under 88 W of ultra-high laser irradiation,with stability surpassing that of commercial silicone color wheels,thanks to its superior Li_(2)O-Al_(2)O_(3)-SiO_(2)(LAS)glass system.Interestingly,we designed an innovative spatially separated two-color segmented wheel structure,effectively mitigating the photon reabsorption phenomenon caused by the overlap of the fluorescent powder absorption peaks.When the ratio of Ce:YAG to Ce:GdYAG is 240:120,it yields white light with a color rendering index(CRI)of 80.2,and luminous flux remaining at 3317.8 lm.When encapsulated in a reflective module,it accurately reflects the true color states of objects.These results collectively indicate that both Ce:YAG PTAF and PTAW possess significant application potential in the realm of high-power laser illumination.展开更多
China’s economy has developed rapidly since its reform and opening-up.However,the different rates of development in various places due to location and policies have led to significant economic differences.Based on th...China’s economy has developed rapidly since its reform and opening-up.However,the different rates of development in various places due to location and policies have led to significant economic differences.Based on the nighttime lighting data of 281 municipal spatial units in China from 2013 to 2021,this study uses spatial autocorrelation,center of gravity shift,and standard deviation ellipse(SDE)analysis to examine the evolution of the spatial pattern of China’s municipal economy.Based on these,it uses a geographically weighted regression(GWR)model to explore the factors influencing the differences in China’s municipal economy and its spatial heterogeneity.The paper reveals the following results.First,China’s municipal economy as a whole shows a growing trend.Second,the SDE shows a“north-south”distribution pattern,and the concentration of China’s economic development has slightly increased,with a significant centripetal distribution.Third,spatial correlation shows spatial positive correlation,the degree of which is increasing,with strong spatial heterogeneity and regional agglomeration.Finally,measuring the influencing factors according to GWR,the industrial structure and education expenditure coefficients generally show a decreasing trend from the southeast coast to the northwest and inland due to the degree of transformation of industrial structure and the lagging effect of education expenditure on economic growth.Conversely,the innovation driver and urban area coefficients show a decreasing trend from the northwest inland to the southeast coast due to the law of diminishing marginal utility of innovation drivers and differences in urbanization development.Government expenditure coefficients show a higher trend in the East and a lower trend in the West due to policy favoritism and market development level.This research can serve as a theoretical reference for China to achieve high-quality development and move toward common prosperity.展开更多
Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-p...Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.展开更多
The utilization of phosphors that achieve full-spectrum lighting has emerged as a prevailing trend in the advancement of white light-emitting diode(WLED)lighting.In this study,we successfully prepared a novel green ph...The utilization of phosphors that achieve full-spectrum lighting has emerged as a prevailing trend in the advancement of white light-emitting diode(WLED)lighting.In this study,we successfully prepared a novel green phosphor Ba_(2)Sc_(2)((BO_(3))_(2)B_(2)O_(5)):Ce^(3+)(BSBO:Ce^(3+))that can be utilized for full-spectrum lighting and low-temperature sensors.BSBO:Ce^(3+)exhibits a broad-band excitation spectrum centered at 410 nm,and a broad-band emission spectrum centered at 525 nm.The internal and external quantum efficiencies of BSBO:Ce^(3+)are 99%and 49%,respectively.The thermal stability of BSBO:Ce^(3+)can be improved by substituting partial Sc atoms with smaller cations.The thermal quenching mechanism of BSBO:Ce^(3+)and the lattice occupancy of Ce ions in BSBO are discussed in detail.Furthermore,by combining the green phosphor BSBO:Ce^(3+),the commercial blue phosphor and the red phosphor on a 405 nm chip,a white light source was obtained with a high average color rendering index(CRI)of 96.6,a low correlated color temperature(CCT)of 3988 K,and a high luminous efficacy of 88.0 Im/W.The lu-minous efficacy of the WLED exhibits negligible degradation during the 1000 h light aging experiment.What's more,an emission peak at 468 nm appears when excited at 352 nm and 80 K,however,the relative intensity of the peaks at 468 and 525 nm gradually weakens with increasing temperature,indicating the potential of this material as a low-temperature sensor.展开更多
Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accel...Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.展开更多
Progressive photoreceptor cell death is one of the main pathological features of age-related macular degeneration and eventually leads to vision loss.Ferroptosis has been demonstrated to be associated with retinal deg...Progressive photoreceptor cell death is one of the main pathological features of age-related macular degeneration and eventually leads to vision loss.Ferroptosis has been demonstrated to be associated with retinal degenerative diseases.However,the molecular mechanisms underlying ferroptosis and photoreceptor cell death in age-related macular degeneration remain largely unexplored.Bioinformatics and biochemical analyses in this study revealed xC^(–),solute carrier family 7 member 11-regulated ferroptosis as the predominant pathological process of photoreceptor cell degeneration in a light-induced dry age-related macular degeneration mouse model.This process involves the nuclear factor-erythroid factor 2-related factor 2-solute carrier family 7 member 11-glutathione peroxidase 4 signaling pathway,through which cystine depletion,iron ion accumulation,and enhanced lipid peroxidation ultimately lead to photoreceptor cell death and subsequent visual function impairment.We demonstrated that solute carrier family 7 member 11 overexpression blocked this process by inhibiting oxidative stress in vitro and in vivo.Conversely,solute carrier family 7 member 11 knockdown or the solute carrier family 7 member 11 inhibitor sulfasalazine and ferroptosis-inducing agent erastin aggravated H_(2)O_(2)-induced ferroptosis of 661W cells.These findings indicate solute carrier family 7 member 11 may be a potential therapeutic target for patients with retinal degenerative diseases including age-related macular degeneration.展开更多
In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FT...In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.展开更多
In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper propos...In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper proposes a novel method for simultaneous 3D shape and color texture capture.First,a linear model correlating camera exposure time with grayscale values is established.Through exposure time calibration,the projected red,green and blue(RGB)light and white-light grayscale values captured by a monochrome cam-era are aligned.Then,three sets of color fringes are projected onto the object to identify optimal pixels for 3D reconstruction.And,three pure-color patterns are projected to synthesize the color texture.Experimental res-ults show that this method effectively achieves synchronous 3D shape and color texture acquisition,offering high speed and precision,and avoids color crosstalk interference common in 3D reconstruction of colored ob-jects using a monochrome camera.展开更多
High-performance deep-blue emitters that meet the BT.2020 standard proposed by the International Telecommunication Union(ITU)for organic light-emitting diodes(OLEDs)remain highly limited.In this work,four deep-blue em...High-performance deep-blue emitters that meet the BT.2020 standard proposed by the International Telecommunication Union(ITU)for organic light-emitting diodes(OLEDs)remain highly limited.In this work,four deep-blue emitters,PP1M,PP2M,PP3M,and PP4M,are designed and synthesized by connecting methylsubstituted biphenyl groups with classical hot exciton building block of phenanthreneimidazole.The introduction of methyl groups contributes to increase the molecular torsion angle and widen the energy gaps for the four compounds.Through appropriate modulation of substitution site,PP3M achieves the highest photoluminescence quantum yield of 85.3%in neat film.As a result,the PP3M-based device exhibits deep-blue light with external quantum efficiency of 7.2%and suppressed efficiency roll-off.The device also shows a small full width at half maximum of 53 nm and the CIE coordinates locate at(0.16,0.04),meeting well with the BT.2020 standard.The high exciton utilization efficiency is primarily ascribed to the hot exciton pathway.This study provides a reliable insight for the design of efficient deep-blue OLEDs with high color purity.展开更多
A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescenc...A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.展开更多
文摘Metal halides have attracted worldwide attention as exceptional optoelectronic materials.Over the past decade,research on metal halides has yielded remarkable progress,and their color-conversion applications have shown considerable promise for commercialization.With the reporting of self-trapped exciton(STE)emission in perovskites,the application of metal halides as broadband emitting materials in the lighting field has gained increas-ing interest.Herein,we provide a comprehensive review of metal halide STE emitters,especially for lighting applications.We begin with highlighting the ideal spectral characteristics and corresponding performance metrics for lighting.This is followed by a systematic summary of the mechanisms,optimization strategies,and recent advances of STE emission in metal halides.Finally,we outline the major challenges and prospective trends for metal halide STE emitters.This review aims to offer valuable insights into metal halide STE emitters and their lighting applications for facilitating the future commercialization.
基金2024 Science and Technology Commissioner Service Group's Emergency Science and Technology Research Project for Wind Disaster Relief in Hainan Province(ZDYF2024YJGG002-8)China Huaneng Group Co.,Ltd.Headquarters Technology Project,Optimization of Photovoltaic Vegetable Greenhouse Structure and Research on Planting Agronomy in Tropical Regions(HNKJ22-HF77)。
文摘In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.
基金supported by the National Natural Science(No.U19A2063)the Jilin Provincial Development Program of Science and Technology (No.20230201080GX)the Jilin Province Education Department Scientific Research Project (No.JJKH20230851KJ)。
文摘The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions and are easy to lose detailed information.So we propose a rendered image denoising method with filtering guided by lighting information.First,we design an image segmentation algorithm based on lighting information to segment the image into different illumination areas.Then,we establish the parameter prediction model guided by lighting information for filtering(PGLF)to predict the filtering parameters of different illumination areas.For different illumination areas,we use these filtering parameters to construct area filters,and the filters are guided by the lighting information to perform sub-area filtering.Finally,the filtering results are fused with auxiliary features to output denoised images for improving the overall denoising effect of the image.Under the physically based rendering tool(PBRT)scene and Tungsten dataset,the experimental results show that compared with other guided filtering denoising methods,our method improves the peak signal-to-noise ratio(PSNR)metrics by 4.2164 dB on average and the structural similarity index(SSIM)metrics by 7.8%on average.This shows that our method can better reduce the noise in complex lighting scenesand improvethe imagequality.
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.
基金supported by grants from Key laboratory of Ecology and Environment in Minority Area,National Ethnic Affairs Commission(KLEEMA202207)。
文摘The rapid expansion of urbanization has led to widespread exposure of wild birds to intensive light at night(LAN).While previous studies have established LAN-induced cognitive impairment in birds,the underlying neurobiological mechanisms remain poorly understood.We hypothesized that LAN exposure impaired cognitive function of birds potentially through neurodegeneration,metabolic dysregulation and neuroinflammatory responses in the telencephalon.Using Zebra Finches(Taeniopygia guttata)as an avian model,under 16L:8D photoperiods,we compared associative learning and memory abilities and neurobiological parameters between experimental groups exposed to dim light at night(LAN)versus nocturnal darkness(CTR).Compared to the CTR birds,the LAN-exposed birds exhibited significantly lower learning and memory performances,reduced neuron density and simplified dendritic morphology in the telencephalons.The key energy metabolic substrates(cholic acid,CTP,D-mannose-6-phosphate)and neuroprotective agents(trehalose,menaquinone,L-gulono-1,4-lactone)in the telencephalons of LAN-exposed birds showed depletion,while oxidative stress markers(methionine sulfoxide)and inflammatory mediators(cis-gondoic acid)exhibited elevation.The neurotransmitter dopamine and histamine metabolic pathway were disrupted in the LAN-exposed birds.The microglias were activated with pro-inflammatory IL-1βand IL-6 levels increasing and anti-inflammatory IL-10 decreasing in the telencephalons of the LAN-exposed birds.These findings indicate a potential mechanistic pathway whereby dim light exposure at night can induce neuroinflammation through oxidative stress-mediated microglial activation,energy metabolism and neurotransmitter homeostasis disruption,ultimately leading to neurodegeneration in the telencephalons of birds.
基金supported by National Natural Science Foundation of China(grant nos.42101124,W2412136)International ResearchCenter of BigData for SustainableDevelopmentGoals(grant no.CBAS2022GSP02)Nanjing University Integrated Research Platform of the Ministry of Education—Top Talents Program.
文摘Green space plays an important role in the sustainable urban development.This study proposes the Green Lighting Index(GLI),integrating nighttime light data from SDGSAT-1 and theNormalized DifferenceVegetation Index(NDVI)from Sentinel-2,to explore the nighttime human activity in green spaces across three major urban agglomerations in China:Beijing-Tianjin-Hebei(BTH),the Yangtze River Delta(YRD),and the Greater Bay Area(GBA).The findings reveal that,for most green spaces,the relationship between nighttime lighting and green spaces is predominantly exclusionary.However,a synergistic relationship is observed in some vibrant green spaces characterized by abundant nighttime lighting.This synergy is evident in high GLI levels,which are strongly positively correlated with per capita Gross Domestic Product(GDP).This research underscores the importance of integrating nighttime perspectives into green space studies.We believe GLI could be used in the assessment of green space quality and contribute to the development of sustainable cities.
文摘Currently,most conventional street lighting systems use a constant light mode throughout the entire night,fromsunset to sunrise,which results in high energy consumption and maintenance costs.Furthermore,scientific research predicts that energy consumption for street lighting will increase in the coming years due to growing demand and rising electricity prices.The dimming strategy is a current trend and a key concept in smart street lighting systems.It involves turning on the road lights only when a vehicle or pedestrian is detected;otherwise,the control system reduces the light intensity of the lamps.Power control is generally implemented using artificial intelligence algorithms such as fuzzy logic,artificial neural networks,or swarm intelligence to manage different events.In our project,the dimming strategy was utilized to reduce costs and energy consumption by at least 48%.This research proposes a standalone photovoltaic plant(SPP)to power a smart street lighting system,which can replace individual solar street lights in a small neighborhood in southwestern Algeria.This design offers advantages such as lower costs and the option to add additional loads a DC pump,a domestic power supply,or technical services to operate the photovoltaic system during the day after charging the storage batteries,especially when there is monthly energy surplus.The energy surplus analyzed in our project ranges from 804 W in January to 4 kW in June,generated by the entire PV installation.To demonstrate the feasibility and reliability of this system,we studied the implementation of the standalone photovoltaic plant,energymanagement,and economic analysis using the Particle SwarmOptimization technique under MATLAB software.
基金Project supported by National Natural Science Foundation of China(62075203,12304460)Zhejiang Provincial Natural Science Foundation of China(LQ23A040007)Basic Public Welfare Research Program of Zhejiang Province(LDT23F05013F05)。
文摘Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty to coexisting with other multivalent activated ions(such as Eu^(3+),Tm^(3+)),which greatly hinders the formation of full spectrum.In this study,a calcium vacancy enhanced self-reduction of Ce^(4+)is realized in CaNaSb_(2)O_(6)F(CNSOF)host under air atmosphere sintering,through which Ce^(3+),Tm^(3+)and Eu^(3+)coexisting in a single-phase full spectrum phosphor was prepared.Notably,the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism.Moreover,the energy transfer kinetics among Tm^(3+),Ce^(3+)and Eu^(3+)were explored.Finally,combined with a 340 nm UV chip,a full spectrum phosphor-converted light-emitting diode(pc-LED)was fabricated,showing a broad emission range from 400 to 750 nm,Commission Internationale de I'Edairage(CIE)of(0.3485,0.3673),Ra of 92 and correlated color temperature(CCT)of 4933 K.Utilizing the variation in emission colors of this phosphor under different UV wavelengths,a dual encryption method combining point character code and fluorescent encryption technique is proposed.This work provides an effective path for Ce^(4+)self-reduction to apply in full spectrum pc-LED and information encryption.
基金Project supported by the Science and Technology Project of Shenzhen City (JSGG20210802154213040)the Guangdong Basic and Applied Basic Research Foundation (2024A1515010001)the Shenzhen Postdoctoral Research Funding Project。
文摘All-inorganic reflective phosphor-in-glass film(PiGF) converter has garnered widespread attentions for high brightness laser-driven white lighting,while its poor color quality and low luminescence stability have been inevitable roadblocks.Herein,the bicolor PiGF containing green-emitting Y3Al3.08Ga1.92O12:Ce3+(YAGG) and red-emitting CaAlSiN_(3):Eu^(2+)(CASN) phosphors bonded on Al2O3substrate was prepared for enabling high color quality laser-driven white lighting in reflective configuration.The bicolor PiGF has high quantum efficiency and good structure stability.By optimizing the CASN content,PiGF thickness and Al_(2)O_(3) content,the reflective bicolor PiGF based white laser diode(LD)displays good luminescence performance with a luminous flux of 451.5 lm and a luminous efficacy of142.3 lm/W and high color quality with a color rendering index(CRI) of 85.3 and a correlated color temperature(CCT) of 5177 K under the incident laser power of 3.15 W,and still has excellent luminescence and color stabilities(CRI and CCT) under the continuous laser excitation of 5.61 W,attributed to the good thermal conductivity and high reflectivity of Al_(2)O_(3) substrate and scattering enhancement effect of Al_(2)O_(3) particles.It can be foreseen that the reflective bicolor PiGF converter provides a promising strategy for enabling high quality laser-driven white lighting.
基金financially supported by the National Natural Science Foundation of China(No.1237040868).
文摘In recent years,the development of solid-state lighting devices has increasingly shifted towards high-power laser illumination,making it imperative to develop fluorescent conversion materials with exceptional thermal stability and luminous quality.In this study,we introduced a highly reflective TiO_(2) substrate in combination with a high thermal conductivity AlN substrate to design a Ce:YAG-PiG-TiO_(2)-AlN Film(Ce:YAG PTAF)color converter with outstanding photothermal performance.Remarkably,the thermal conductivity of this material reaches 48.28 W m^(-1) K^(-1).Notably,the optimized PTAF can withstand a high-power output of up to 12.14 W in a static environment,with a maximum luminous flux(LFmax)of 2284.6 lm and maximum luminous efficacy(LEmax)of 222.35 lm W^(-1),showcasing its excellent optical properties.Furthermore,the fabricated Ce:YAG-PiG-TiO_(2)-AlN-Wheel(Ce:YAG PTAW),equipped with a motor operating at 7200 r/min,emits an extraordinary brightness of 4404 lm under 88 W of ultra-high laser irradiation,with stability surpassing that of commercial silicone color wheels,thanks to its superior Li_(2)O-Al_(2)O_(3)-SiO_(2)(LAS)glass system.Interestingly,we designed an innovative spatially separated two-color segmented wheel structure,effectively mitigating the photon reabsorption phenomenon caused by the overlap of the fluorescent powder absorption peaks.When the ratio of Ce:YAG to Ce:GdYAG is 240:120,it yields white light with a color rendering index(CRI)of 80.2,and luminous flux remaining at 3317.8 lm.When encapsulated in a reflective module,it accurately reflects the true color states of objects.These results collectively indicate that both Ce:YAG PTAF and PTAW possess significant application potential in the realm of high-power laser illumination.
基金funded by the Project of Philosophy and Social Science Key Research Base−Industrial Transformation and Innovation Research Center of Zigong Municipal Federation of Social Sciences[Grant No.CZ23B02].
文摘China’s economy has developed rapidly since its reform and opening-up.However,the different rates of development in various places due to location and policies have led to significant economic differences.Based on the nighttime lighting data of 281 municipal spatial units in China from 2013 to 2021,this study uses spatial autocorrelation,center of gravity shift,and standard deviation ellipse(SDE)analysis to examine the evolution of the spatial pattern of China’s municipal economy.Based on these,it uses a geographically weighted regression(GWR)model to explore the factors influencing the differences in China’s municipal economy and its spatial heterogeneity.The paper reveals the following results.First,China’s municipal economy as a whole shows a growing trend.Second,the SDE shows a“north-south”distribution pattern,and the concentration of China’s economic development has slightly increased,with a significant centripetal distribution.Third,spatial correlation shows spatial positive correlation,the degree of which is increasing,with strong spatial heterogeneity and regional agglomeration.Finally,measuring the influencing factors according to GWR,the industrial structure and education expenditure coefficients generally show a decreasing trend from the southeast coast to the northwest and inland due to the degree of transformation of industrial structure and the lagging effect of education expenditure on economic growth.Conversely,the innovation driver and urban area coefficients show a decreasing trend from the northwest inland to the southeast coast due to the law of diminishing marginal utility of innovation drivers and differences in urbanization development.Government expenditure coefficients show a higher trend in the East and a lower trend in the West due to policy favoritism and market development level.This research can serve as a theoretical reference for China to achieve high-quality development and move toward common prosperity.
基金supported by the National Key Research and Development Program(MOST,No.2022YFE0108800)the National Natural Science Foundation of China(Nos.52272165,U2005213 and 52172157)the Major Science and Technology Projects of Xiamen Science and Technology Bureau(No.3502Z20231018).
文摘Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.
基金the National Natural Science Foundation of China(22003035,21963006,22073061)the Project of Shaanxi Province Youth Science and Technology New Star(2023KJXX-076)the National Training Program of Innovation and Entrepreneurship for Undergraduates(202314390018)。
文摘The utilization of phosphors that achieve full-spectrum lighting has emerged as a prevailing trend in the advancement of white light-emitting diode(WLED)lighting.In this study,we successfully prepared a novel green phosphor Ba_(2)Sc_(2)((BO_(3))_(2)B_(2)O_(5)):Ce^(3+)(BSBO:Ce^(3+))that can be utilized for full-spectrum lighting and low-temperature sensors.BSBO:Ce^(3+)exhibits a broad-band excitation spectrum centered at 410 nm,and a broad-band emission spectrum centered at 525 nm.The internal and external quantum efficiencies of BSBO:Ce^(3+)are 99%and 49%,respectively.The thermal stability of BSBO:Ce^(3+)can be improved by substituting partial Sc atoms with smaller cations.The thermal quenching mechanism of BSBO:Ce^(3+)and the lattice occupancy of Ce ions in BSBO are discussed in detail.Furthermore,by combining the green phosphor BSBO:Ce^(3+),the commercial blue phosphor and the red phosphor on a 405 nm chip,a white light source was obtained with a high average color rendering index(CRI)of 96.6,a low correlated color temperature(CCT)of 3988 K,and a high luminous efficacy of 88.0 Im/W.The lu-minous efficacy of the WLED exhibits negligible degradation during the 1000 h light aging experiment.What's more,an emission peak at 468 nm appears when excited at 352 nm and 80 K,however,the relative intensity of the peaks at 468 and 525 nm gradually weakens with increasing temperature,indicating the potential of this material as a low-temperature sensor.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0530000)the Discipline Construction Foundation of“Double World-class Project”.
文摘Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.
基金supported by the National Natural Science Foundation of China,Nos.82171076(to XS)and U22A20311(to XS),82101168(to TL)Shanghai Science and technology Innovation Action Plan,No.23Y11901300(to JS)+1 种基金Science and Technology Commission of Shanghai Municipality,No.21ZR1451500(to TL)Shanghai Pujiang Program,No.22PJ1412200(to BY)。
文摘Progressive photoreceptor cell death is one of the main pathological features of age-related macular degeneration and eventually leads to vision loss.Ferroptosis has been demonstrated to be associated with retinal degenerative diseases.However,the molecular mechanisms underlying ferroptosis and photoreceptor cell death in age-related macular degeneration remain largely unexplored.Bioinformatics and biochemical analyses in this study revealed xC^(–),solute carrier family 7 member 11-regulated ferroptosis as the predominant pathological process of photoreceptor cell degeneration in a light-induced dry age-related macular degeneration mouse model.This process involves the nuclear factor-erythroid factor 2-related factor 2-solute carrier family 7 member 11-glutathione peroxidase 4 signaling pathway,through which cystine depletion,iron ion accumulation,and enhanced lipid peroxidation ultimately lead to photoreceptor cell death and subsequent visual function impairment.We demonstrated that solute carrier family 7 member 11 overexpression blocked this process by inhibiting oxidative stress in vitro and in vivo.Conversely,solute carrier family 7 member 11 knockdown or the solute carrier family 7 member 11 inhibitor sulfasalazine and ferroptosis-inducing agent erastin aggravated H_(2)O_(2)-induced ferroptosis of 661W cells.These findings indicate solute carrier family 7 member 11 may be a potential therapeutic target for patients with retinal degenerative diseases including age-related macular degeneration.
文摘In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.
文摘In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper proposes a novel method for simultaneous 3D shape and color texture capture.First,a linear model correlating camera exposure time with grayscale values is established.Through exposure time calibration,the projected red,green and blue(RGB)light and white-light grayscale values captured by a monochrome cam-era are aligned.Then,three sets of color fringes are projected onto the object to identify optimal pixels for 3D reconstruction.And,three pure-color patterns are projected to synthesize the color texture.Experimental res-ults show that this method effectively achieves synchronous 3D shape and color texture acquisition,offering high speed and precision,and avoids color crosstalk interference common in 3D reconstruction of colored ob-jects using a monochrome camera.
文摘High-performance deep-blue emitters that meet the BT.2020 standard proposed by the International Telecommunication Union(ITU)for organic light-emitting diodes(OLEDs)remain highly limited.In this work,four deep-blue emitters,PP1M,PP2M,PP3M,and PP4M,are designed and synthesized by connecting methylsubstituted biphenyl groups with classical hot exciton building block of phenanthreneimidazole.The introduction of methyl groups contributes to increase the molecular torsion angle and widen the energy gaps for the four compounds.Through appropriate modulation of substitution site,PP3M achieves the highest photoluminescence quantum yield of 85.3%in neat film.As a result,the PP3M-based device exhibits deep-blue light with external quantum efficiency of 7.2%and suppressed efficiency roll-off.The device also shows a small full width at half maximum of 53 nm and the CIE coordinates locate at(0.16,0.04),meeting well with the BT.2020 standard.The high exciton utilization efficiency is primarily ascribed to the hot exciton pathway.This study provides a reliable insight for the design of efficient deep-blue OLEDs with high color purity.
文摘A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.
