1《The Unbearable Lightness of Being》简介
《The Unbearable Lightness of Being》是捷克作家米兰·昆德拉的作品，发表于1984年。其被我国读者所了解应在1987年韩少功和韩刚合译该书之后。自此，专家学者们对小说又有了一系...1《The Unbearable Lightness of Being》简介
《The Unbearable Lightness of Being》是捷克作家米兰·昆德拉的作品，发表于1984年。其被我国读者所了解应在1987年韩少功和韩刚合译该书之后。自此，专家学者们对小说又有了一系列的重译和解读。本文讨论所使用的是Michael Henry Heim所翻译的英文电子版.展开更多
A perceptual lightness anchoring model based on visual cognition is proposed. It can recover absolute lightness of natural images using filling-in mechanism from single-scale boundaries. First, it adapts the response ...A perceptual lightness anchoring model based on visual cognition is proposed. It can recover absolute lightness of natural images using filling-in mechanism from single-scale boundaries. First, it adapts the response of retinal photoreceptors to varying levels of illumination. Then luminance-correlated contrast information can be obtained through multiplex encoding without additional luminance channel. Dynamic normalization is used to get smooth and continuous boundary contours. Different boundaries are used for ON and OFF channel diffusion layers. Theoretical analysis and simulation results indicate that the model could recover natural images under varying illumination, and solve the trapping, blurring and fogging problems to some extent.展开更多
This paper proposed a new algorithm to separate leukocytes from cytological image by setting parameters of lightness transformation based on the RGB color space, which can make the targets’ color in different areas. ...This paper proposed a new algorithm to separate leukocytes from cytological image by setting parameters of lightness transformation based on the RGB color space, which can make the targets’ color in different areas. In our procedure, an operator is employed in using color features. According to their histogram distribution of hue component in HSL color space after enhancing the contrast of image in RGB color space, the threshold of segmentation between leukocyte and erythrocyte could be achieved well. Especially, this algorithm is more efficient than monochrome for leukocyte segmentation, and the results of experiments show that it provides a good tool for cytological image, which can increase accuracy of segmentation of leukocyte.展开更多
Design concept Design Theme Color is not only a visual grammar but also a symbolic language of the spirit.This series,“In the Name of Color,”explores three states of the female inner world:awakening in chaos,order i...Design concept Design Theme Color is not only a visual grammar but also a symbolic language of the spirit.This series,“In the Name of Color,”explores three states of the female inner world:awakening in chaos,order in return,and regeneration in flow.The works—Eye of the Storm,Back to the Seed,and Source—form a stream-of-consciousness journey from within to without.Based on the COLORO color system,the series is constructed through hue,chroma,lightness,and domain ratio,treating color as both emotional force and symbolic medium.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
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 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
As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical ...As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical traits.Although extensive research has been conducted on light-mediated growth regulation in horticultural crops,most reviews focus primarily on leafy and fruiting vegetables,with limited attention given to berry crops such as strawberries.Additionally,most existing reviews concentrate on one or several growth stages,failing to systematically characterize light’s effects throughout the entire growth cycle and postharvest stage.This review briefly summarizes the regulatory roles of light across key stages of strawberry growth,including seedling propagation,vegetative growth,reproductive growth,and postharvest stages.It seeks to address the knowledge gap by systematically organizing research findings across these developmental phases.The integrated analysis provides a theoretical foundation for designing stage-specific lighting strategies to improve strawberry yield and quality.展开更多
Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light condi...Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light conditions are considerably smaller in intensity and possess greater components of non-normal incidence.Yet,indoor light-driven,stand-alone devices can offer sustainable advances in next-generation technologies such as the Internet of Things.Here,we present a non-invasive solution to aid in photovoltaic indoor light collection—radially distributed waveguide-encoded lattice(RDWEL)slim films(thickness 1.5 mm).Embedded with a monotonical radial array of cylindrical waveguides(±20°),the RDWEL demonstrates seamless light collection(FoV(fields of view)=74.5°)and imparts enhancements in JSC(short circuit current density)of 44%and 14%for indoor and outdoor lighting conditions,respectively,when coupled to a photovoltaic device and compared to an unstructured but otherwise identical slim film coating.展开更多
The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly add...The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.展开更多
A diverse range of light and waves,spanning from near-infrared to ultraviolet,alongside ultrasound,have proven effective in propelling nanomotors.This review encapsulates the advancements in nanomotor research propell...A diverse range of light and waves,spanning from near-infrared to ultraviolet,alongside ultrasound,have proven effective in propelling nanomotors.This review encapsulates the advancements in nanomotor research propelled by waves of varying frequencies.It delves into the driving mechanisms and control methodologies of different nanomotor types,emphasizing the role of frequency.Nanomotors can be classified based on the frequency of the driving wave,encompassing ultraviolet light-driven,visible light-driven,near-infrared-driven,and ultrasounddriven variants.Each category corresponds to distinct propulsion mechanisms,including momentum transfer,photothermal effects,self-electrophoresis,and acoustic radiation force.Notably,visible light and near-infrared radiation predominantly propel momentum transfer nanomotors,while photothermal nanomotors are chiefly active within the infrared spectrum.Ultraviolet light drives most self-electrophoretic nanomotors,while ultrasound-driven nanomotors respond to acoustic radiation force.Furthermore,precise control over nanomotor speed and direction is achievable by adjusting the frequency of incident waves within a narrow range,modulating wave absorption rates.Lastly,this paper explores microwave nanomotors,an area yet to be reported,shedding light on potential driving mechanisms.展开更多
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains...Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.展开更多
The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,t...The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.展开更多
Metal halides are an important class of optoelectronic materials combining exceptional optical and electronic properties.An inherent advantage of metal halides is their solution synthesis and processability,which rend...Metal halides are an important class of optoelectronic materials combining exceptional optical and electronic properties.An inherent advantage of metal halides is their solution synthesis and processability,which render them as low-cost and environmentally friendly materials for a range of applications from photovoltaics and photodetection to solid-state lighting(SSL).In this study,we synthesized three previously unreported lead-free organic–inorganic hybrid copper halides:(OA)_(4)CuX_(5)(X=Br,I;OA^(+) =C_(8)H_(17)NH_(3)^(+) ,n-octylammonium cation)and(HA)_(2)CuI_(3)(HA^(+) =C_(6)H_(13)NH_(3)^(+) ,n-hexylammonium cation),all of which exhibit broadband emissions arising from self-trapped excitons(STEs).Among these compounds,(OA)_(4)CuI_(5) demonstrates tunable dual-band white-light emission with a high color rendering index value of 91 at room temperature.Temperature-dependent photoluminescence measurements and first-principles calculations reveal distinct behaviors between the two emission states in(OA)_(4)CuI_(5).These findings highlight the potential of copper halide compounds for optoelectronic applications,particularly in the development of environmentally friendly solid-state lighting technologies.展开更多
UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important...UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.展开更多
文摘1《The Unbearable Lightness of Being》简介
《The Unbearable Lightness of Being》是捷克作家米兰·昆德拉的作品，发表于1984年。其被我国读者所了解应在1987年韩少功和韩刚合译该书之后。自此，专家学者们对小说又有了一系列的重译和解读。本文讨论所使用的是Michael Henry Heim所翻译的英文电子版.
文摘A perceptual lightness anchoring model based on visual cognition is proposed. It can recover absolute lightness of natural images using filling-in mechanism from single-scale boundaries. First, it adapts the response of retinal photoreceptors to varying levels of illumination. Then luminance-correlated contrast information can be obtained through multiplex encoding without additional luminance channel. Dynamic normalization is used to get smooth and continuous boundary contours. Different boundaries are used for ON and OFF channel diffusion layers. Theoretical analysis and simulation results indicate that the model could recover natural images under varying illumination, and solve the trapping, blurring and fogging problems to some extent.
文摘This paper proposed a new algorithm to separate leukocytes from cytological image by setting parameters of lightness transformation based on the RGB color space, which can make the targets’ color in different areas. In our procedure, an operator is employed in using color features. According to their histogram distribution of hue component in HSL color space after enhancing the contrast of image in RGB color space, the threshold of segmentation between leukocyte and erythrocyte could be achieved well. Especially, this algorithm is more efficient than monochrome for leukocyte segmentation, and the results of experiments show that it provides a good tool for cytological image, which can increase accuracy of segmentation of leukocyte.
文摘Design concept Design Theme Color is not only a visual grammar but also a symbolic language of the spirit.This series,“In the Name of Color,”explores three states of the female inner world:awakening in chaos,order in return,and regeneration in flow.The works—Eye of the Storm,Back to the Seed,and Source—form a stream-of-consciousness journey from within to without.Based on the COLORO color system,the series is constructed through hue,chroma,lightness,and domain ratio,treating color as both emotional force and symbolic medium.
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.
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.
基金supported by National Key Research and Development Program of China(2023YFF1001700)the Unveiling and Leading Projects(2022kj05)+1 种基金Yafu Technology Innovation Team of Jiangsu Vocational College of Agriculture and Forestry(2024kj02)the Innovation&Entrepreneurship Training Program for College Students of Qingdao Agricultural University(QNDC20250149).
文摘As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical traits.Although extensive research has been conducted on light-mediated growth regulation in horticultural crops,most reviews focus primarily on leafy and fruiting vegetables,with limited attention given to berry crops such as strawberries.Additionally,most existing reviews concentrate on one or several growth stages,failing to systematically characterize light’s effects throughout the entire growth cycle and postharvest stage.This review briefly summarizes the regulatory roles of light across key stages of strawberry growth,including seedling propagation,vegetative growth,reproductive growth,and postharvest stages.It seeks to address the knowledge gap by systematically organizing research findings across these developmental phases.The integrated analysis provides a theoretical foundation for designing stage-specific lighting strategies to improve strawberry yield and quality.
基金supported by the European Research Council(ERC)under the European Union's Horizon 2020 Research and Innovation Programme(Grant Agreement No.818762)the Engineering and Physical Sciences Research Council(Grant No.EP/V048953/1)and the Isaac Newton Trust(grant 22.39(m))。
文摘Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light conditions are considerably smaller in intensity and possess greater components of non-normal incidence.Yet,indoor light-driven,stand-alone devices can offer sustainable advances in next-generation technologies such as the Internet of Things.Here,we present a non-invasive solution to aid in photovoltaic indoor light collection—radially distributed waveguide-encoded lattice(RDWEL)slim films(thickness 1.5 mm).Embedded with a monotonical radial array of cylindrical waveguides(±20°),the RDWEL demonstrates seamless light collection(FoV(fields of view)=74.5°)and imparts enhancements in JSC(short circuit current density)of 44%and 14%for indoor and outdoor lighting conditions,respectively,when coupled to a photovoltaic device and compared to an unstructured but otherwise identical slim film coating.
基金supported by the Key Research and Development Task Project of Xinjiang Uygur Autonomous Region(No.2022B02033)the National Natural Science Foundation of China(Nos.42211530566 and 42311530066)+2 种基金the NSFC-FNRS Joint Program BIOAGRIFILM(No.FNRS PINT-BILATM 2022)the Science and Technology Project of Bijie Tobacco Company of Guizhou Province(No.2022520500240192)the Agricultural Science and Technology Innovation Program(ASTIP)。
文摘The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.
基金supported by the National Key Research and Development Program of China(2021YFA1401103)the National Natural Science Foundation of China(52473109,52073071)+3 种基金China Scholarship Council(CSC)(202306790056)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_2301)111 Project(B23008)the Innovative Leading Talent Team supported by 2022Wuxi Taihu Talent Program(1096010241230120)。
文摘A diverse range of light and waves,spanning from near-infrared to ultraviolet,alongside ultrasound,have proven effective in propelling nanomotors.This review encapsulates the advancements in nanomotor research propelled by waves of varying frequencies.It delves into the driving mechanisms and control methodologies of different nanomotor types,emphasizing the role of frequency.Nanomotors can be classified based on the frequency of the driving wave,encompassing ultraviolet light-driven,visible light-driven,near-infrared-driven,and ultrasounddriven variants.Each category corresponds to distinct propulsion mechanisms,including momentum transfer,photothermal effects,self-electrophoresis,and acoustic radiation force.Notably,visible light and near-infrared radiation predominantly propel momentum transfer nanomotors,while photothermal nanomotors are chiefly active within the infrared spectrum.Ultraviolet light drives most self-electrophoretic nanomotors,while ultrasound-driven nanomotors respond to acoustic radiation force.Furthermore,precise control over nanomotor speed and direction is achievable by adjusting the frequency of incident waves within a narrow range,modulating wave absorption rates.Lastly,this paper explores microwave nanomotors,an area yet to be reported,shedding light on potential driving mechanisms.
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金supported by the Department of Science and Technology of Jilin Province(20220508112RC).
文摘Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.
基金financially supported by the National Natural Science Foundation of China(grant no.42120104005)Guizhou Provincial 2021 Science and Technology Subsidies(grant no.GZ2021SIG)+1 种基金Guizhou Provincial Science and Technology Projects(grant nos.ZK[2024]087GCC[2023]060)。
文摘The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.
基金primarily supported by Grant 2022066 from the U.S.-Israel Binational Science Foundation(BSF)support by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Award Number DESC0025485(material synthesis and structural characterization)+1 种基金supported by the U.S.DOE,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357the support from the US National Science Foundation through awards DMR-2317008。
文摘Metal halides are an important class of optoelectronic materials combining exceptional optical and electronic properties.An inherent advantage of metal halides is their solution synthesis and processability,which render them as low-cost and environmentally friendly materials for a range of applications from photovoltaics and photodetection to solid-state lighting(SSL).In this study,we synthesized three previously unreported lead-free organic–inorganic hybrid copper halides:(OA)_(4)CuX_(5)(X=Br,I;OA^(+) =C_(8)H_(17)NH_(3)^(+) ,n-octylammonium cation)and(HA)_(2)CuI_(3)(HA^(+) =C_(6)H_(13)NH_(3)^(+) ,n-hexylammonium cation),all of which exhibit broadband emissions arising from self-trapped excitons(STEs).Among these compounds,(OA)_(4)CuI_(5) demonstrates tunable dual-band white-light emission with a high color rendering index value of 91 at room temperature.Temperature-dependent photoluminescence measurements and first-principles calculations reveal distinct behaviors between the two emission states in(OA)_(4)CuI_(5).These findings highlight the potential of copper halide compounds for optoelectronic applications,particularly in the development of environmentally friendly solid-state lighting technologies.
基金supported by the National Natural Science Foundation of China(Grant No.32072623)the National Key Research and Development Program of China(Grant No.2021YFD1601103).
文摘UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.
