Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promisi...Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promising luminescence thermometric material,Ta^(5+)-substituted K_(0.5)Na_(0.5)NbO_(3):0.003Er^(3+)transparent ferroelectric ceramics.The temperature sensing sensitivity is significantly improved by adjusting the concentration of Ta^(5+)in the material.Specifically,utilizing the fluorescence intensity ratio from the 2H_(11/2) and 4S_(3/2) thermally coupled states of Er^(3+)as a detecting signal within the temperature range of 273–543 K,an optimal maximum absolute sensitivity of 0.0058 K–1 and relative sensitivity of 0.0158 K–1 are achieved for K_(0.5)Na_(0.5)NbO_(3):0.65Ta^(5+)/0.003Er^(3+).Simultaneously,as the concentration of Ta5+increase,a unique evolution of structural phase transitions is observed from orthorhombic to tetragonal and then to cubic.This is accompanied by an improvement in luminescence temperature sensing properties,and the best sensitivity is demonstrated in the cubic-phase region.Intriguingly,a huge change in infrared luminescence properties as a function of temperature is found around the structure transition temperature of the samples.These results indicate a promising potential for achieving highly sensitive thermometry or monitoring phase structure transitions through luminescence thermometry behavior in the K_(0.5)Na_(0.5)NbO_(3) host.展开更多
Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A...Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A （UV- A） light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.11774052)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX22_0048).
文摘Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promising luminescence thermometric material,Ta^(5+)-substituted K_(0.5)Na_(0.5)NbO_(3):0.003Er^(3+)transparent ferroelectric ceramics.The temperature sensing sensitivity is significantly improved by adjusting the concentration of Ta^(5+)in the material.Specifically,utilizing the fluorescence intensity ratio from the 2H_(11/2) and 4S_(3/2) thermally coupled states of Er^(3+)as a detecting signal within the temperature range of 273–543 K,an optimal maximum absolute sensitivity of 0.0058 K–1 and relative sensitivity of 0.0158 K–1 are achieved for K_(0.5)Na_(0.5)NbO_(3):0.65Ta^(5+)/0.003Er^(3+).Simultaneously,as the concentration of Ta5+increase,a unique evolution of structural phase transitions is observed from orthorhombic to tetragonal and then to cubic.This is accompanied by an improvement in luminescence temperature sensing properties,and the best sensitivity is demonstrated in the cubic-phase region.Intriguingly,a huge change in infrared luminescence properties as a function of temperature is found around the structure transition temperature of the samples.These results indicate a promising potential for achieving highly sensitive thermometry or monitoring phase structure transitions through luminescence thermometry behavior in the K_(0.5)Na_(0.5)NbO_(3) host.
文摘Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A （UV- A） light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.
