We report an efficient power tapping device working in near infra-red (800 nm) wavelength region based on UV-in- scribed 45° tilted fiber grating (45°-TFG) structure. Five 45°-TFGs were UV-inscribed in ...We report an efficient power tapping device working in near infra-red (800 nm) wavelength region based on UV-in- scribed 45° tilted fiber grating (45°-TFG) structure. Five 45°-TFGs were UV-inscribed in hydrogenated PS750 fiber using a custom-designed phase mask with different grating lengths of 3 mm, 5 mm, 9 mm, 12 mm and 15 mm, showing polarization dependent losses (PDLs) of 1 dB, 3 dB, 7 dB, 10 dB and 13 dB, respectively. The power side-tapping efficiency is clearly depending on the grating strength. It has been identified that the power tapping efficiency increases with the grating strength and deceases along the grating length. The side-tapped power profile has also been examined in azimuthal direction, showing a near-Gaussian distribution. These experimental results clearly demonstrated that 45°- TFGs may be used as in-fiber power tapping devices for applications requiring in-line signal monitoring.展开更多
Citrus canker,caused by Xanthomonas citri subsp.citri(Xcc),is a serious bacterial disease that affects citrus production worldwide.Citron C-05(Citrus medica)is the only germplasm in the Citrus genus that has been iden...Citrus canker,caused by Xanthomonas citri subsp.citri(Xcc),is a serious bacterial disease that affects citrus production worldwide.Citron C-05(Citrus medica)is the only germplasm in the Citrus genus that has been identified to exhibit strong resistance to Xcc.However,it has not been determined when,where,and how Xcc is restricted in the tissues of Citron C-05 during the infection process.In the present study,we investigated the spatiotemporal growth dynamics of an eGFP-labeled virulent Xcc(eGFP-Xcc)strain in Citron C-05 along with five susceptible biotypes(i.e.,lemon,pummelo,sour orange,sweet orange,and ponkan mandarin)upon inoculation via the spraying or leaf infiltration of a bacterial suspension.The results from extensive confocal laser scanning microscopy analyses showed that while Xcc grew rapidly in plants of all five susceptible genotypes,Xcc was severely restricted in the epidermal and mesophyll cell layers of the leaves of Citron C-05 in the early stage of infection.Not surprisingly,resistance against Xcc in Citron C-05 was found to be associated with the production of reactive oxygen species and hypersensitive response-like cell death,as well as greater upregulation of several defense-related genes,including a pathogenesis-related gene(PR1)and a glutathione S-transferase gene(GST1),compared with sweet orange as a susceptible control.Taken together,our results not only provide further valuable details of the spatiotemporal dynamics of the host entry,propagation,and spread of Xcc in both resistant and susceptible citrus plants but also suggest that resistance to Xcc in Citron C-05 may be attributed to the activation of multiple defense mechanisms.展开更多
Chronic stress has been the popular phenomenon in the modern society. But we have not yet resolved the problem effectively. A novel protein in pig spleen, which possesses immunosuppressive activity, has been purified ...Chronic stress has been the popular phenomenon in the modern society. But we have not yet resolved the problem effectively. A novel protein in pig spleen, which possesses immunosuppressive activity, has been purified in this study. Its molecular weight about 200 kDa and three subunits composition were fractionated by SDS-PAGE. The protein inhibited mouse T-lymphocyte proliferation by the induced concanavalin A (ConA) and regulatory volume decrease (RVD), which may be due to the decreased Kv1.3 expression and activity. In addition, we have raised successfully its polyclonal antibody, which could reverse the inhibited lymphocyte proliferation by the immuno-suppressive protein. And the antibody could be used to coat plate for ELISA assay. Therefore, the antibody will have the potential to provide a basis for applying to clinical stress diseases in the future.展开更多
Due to their excellent advantages such as low toxicity,superior optoelectronic properties,low-temperature fabrication,and costeffectiveness,Sn-based perovskites have become the most promising alternatives for high per...Due to their excellent advantages such as low toxicity,superior optoelectronic properties,low-temperature fabrication,and costeffectiveness,Sn-based perovskites have become the most promising alternatives for high performance lead-free perovskite solar cells.However,the character of Sn ^(2+)is easily oxidized toSn ^(4+),causing unnecessary p-type self-doping and high leakage current.More seriously,trap-induced non-radiative recombination from rapid crystallization causes into large energy loss with a low open circuit voltage.Therefore,the Sn-based solar cells have efficiency far behind the Pb-based solar cells.Herein,the polymer poly(ethylene glycol)diacrylate(PEGDA)is used to control crystal growth and passivate the defects in FA_(0.85)PEA_(0.15)SnI_(3) thin film.This Sn-perovskite layer shows compact crystal with large grain size and reduced defects.Optimized perovskite thin film is further processed to fabricate the inverted solar cell with device structure of ITO(indium tin oxide)/PEDOT:PSS(Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate))/FA_(0.85)PEA_(0.15)SnI_(3)/ICBA(indene-C60 bisadduct)/BCP(bathocuproine)/Ag,which shows the power conversion efficiency(PCE)of 11.45%with voltage of 0.82 V.Moreover,corresponding perovskite solar cells exhibit an enhanced stability due to PEGDA induced compressive strain in perovskite.This work could shed light on one of successful attempts to improve Sn-based solar cell efficiency for sustainable energy conversion.展开更多
A highly efficient second-harmonic source is integrated into a silicon nitride microring resonator,unlocking the potential for advanced chip-scale devices such as miniaturized atomic clocks and fully integrated self-r...A highly efficient second-harmonic source is integrated into a silicon nitride microring resonator,unlocking the potential for advanced chip-scale devices such as miniaturized atomic clocks and fully integrated self-referenced microcombs.展开更多
We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/...We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/50 fiber loop mirror(FLM), a 10/90 FLM, and a piece of large-gain Tm-doped double-clad fiber pumped by a 793 nm laser diode. The 10/90 FLM is not only used as an output mirror, but also acts as a periodical saturable absorber for initiating DSR mode locking. The stable DSR pulses are generated at the center wavelength as long as 2080.4 nm, and the pulse duration can be tunable from 780 to 3240 ps as the pump power is increased. The maximum average output power is 1.27 W, corresponding to a pulse energy of 290 nJ and a nearly constant peak power of 93 W. This is, to the best of our knowledge, the longest wavelength for DSR operation in a mode-locked fiber laser.展开更多
Raman and Brillouin lasers based on a high-quality(high-Q) whispering gallery mode microresonator(WGMR)are usually achieved by employing a tunable single-frequency laser as a pump source. Here, we experimentally demon...Raman and Brillouin lasers based on a high-quality(high-Q) whispering gallery mode microresonator(WGMR)are usually achieved by employing a tunable single-frequency laser as a pump source. Here, we experimentally demonstrate visible Raman and Brillouin lasers using a compact microresonator/ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN)-fiber hybrid system by incorporating a WGMR with a fiber-compatible distributed Bragg reflector/fiber Bragg grating to form a Fabry–Perot(F-P) fiber cavity and using a piece of Pr:ZBLAN fiber as gain medium.The high-Q silica-microsphere not only offers a Rayleigh-scattering-induced backreflection to form the ~635 nm red laser oscillation in the F-P fiber cavity, but also provides a nonlinear gain in the WGMR itself to generate either stimulated Raman scattering or stimulated Brillouin scattering. Up to six-order cascaded Raman lasers at0.65 μm, 0.67 μm, 0.69 μm, 0.71 μm, 0.73 μm, and 0.76 μm are achieved, respectively. Moreover, a Brillouin laser at 635.54 nm is clearly observed. This is, to the best of our knowledge, the first demonstration of visible microresonator-based lasers created by combining a Pr:ZBLAN fiber. This structure can effectively extend the laser wavelength in the WGMR to the visible waveband and may find potential applications in underwater communication, biomedical diagnosis, microwave generation, and spectroscopy.展开更多
文摘We report an efficient power tapping device working in near infra-red (800 nm) wavelength region based on UV-in- scribed 45° tilted fiber grating (45°-TFG) structure. Five 45°-TFGs were UV-inscribed in hydrogenated PS750 fiber using a custom-designed phase mask with different grating lengths of 3 mm, 5 mm, 9 mm, 12 mm and 15 mm, showing polarization dependent losses (PDLs) of 1 dB, 3 dB, 7 dB, 10 dB and 13 dB, respectively. The power side-tapping efficiency is clearly depending on the grating strength. It has been identified that the power tapping efficiency increases with the grating strength and deceases along the grating length. The side-tapped power profile has also been examined in azimuthal direction, showing a near-Gaussian distribution. These experimental results clearly demonstrated that 45°- TFGs may be used as in-fiber power tapping devices for applications requiring in-line signal monitoring.
基金supported by the Key Project of International Cooperation and Exchange of the National Natural Science Foundation of China(No.31720103915)a Project of the National Natural Science Foundation of China(No.31572111)the Key Laboratory of Crop Germplasm Innovation and Resource Utilization Science Foundation(No.16KFXM01).
文摘Citrus canker,caused by Xanthomonas citri subsp.citri(Xcc),is a serious bacterial disease that affects citrus production worldwide.Citron C-05(Citrus medica)is the only germplasm in the Citrus genus that has been identified to exhibit strong resistance to Xcc.However,it has not been determined when,where,and how Xcc is restricted in the tissues of Citron C-05 during the infection process.In the present study,we investigated the spatiotemporal growth dynamics of an eGFP-labeled virulent Xcc(eGFP-Xcc)strain in Citron C-05 along with five susceptible biotypes(i.e.,lemon,pummelo,sour orange,sweet orange,and ponkan mandarin)upon inoculation via the spraying or leaf infiltration of a bacterial suspension.The results from extensive confocal laser scanning microscopy analyses showed that while Xcc grew rapidly in plants of all five susceptible genotypes,Xcc was severely restricted in the epidermal and mesophyll cell layers of the leaves of Citron C-05 in the early stage of infection.Not surprisingly,resistance against Xcc in Citron C-05 was found to be associated with the production of reactive oxygen species and hypersensitive response-like cell death,as well as greater upregulation of several defense-related genes,including a pathogenesis-related gene(PR1)and a glutathione S-transferase gene(GST1),compared with sweet orange as a susceptible control.Taken together,our results not only provide further valuable details of the spatiotemporal dynamics of the host entry,propagation,and spread of Xcc in both resistant and susceptible citrus plants but also suggest that resistance to Xcc in Citron C-05 may be attributed to the activation of multiple defense mechanisms.
文摘Chronic stress has been the popular phenomenon in the modern society. But we have not yet resolved the problem effectively. A novel protein in pig spleen, which possesses immunosuppressive activity, has been purified in this study. Its molecular weight about 200 kDa and three subunits composition were fractionated by SDS-PAGE. The protein inhibited mouse T-lymphocyte proliferation by the induced concanavalin A (ConA) and regulatory volume decrease (RVD), which may be due to the decreased Kv1.3 expression and activity. In addition, we have raised successfully its polyclonal antibody, which could reverse the inhibited lymphocyte proliferation by the immuno-suppressive protein. And the antibody could be used to coat plate for ELISA assay. Therefore, the antibody will have the potential to provide a basis for applying to clinical stress diseases in the future.
基金This work is financially supported by Shenzhen Science and Technology Innovation Committee(No.JCYJ20190809172615277)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515111065)Shenzhen Municipal Development and Reform Commission,New Energy Technology Engineering Laboratory(No.SDRC[2016]172).
文摘Due to their excellent advantages such as low toxicity,superior optoelectronic properties,low-temperature fabrication,and costeffectiveness,Sn-based perovskites have become the most promising alternatives for high performance lead-free perovskite solar cells.However,the character of Sn ^(2+)is easily oxidized toSn ^(4+),causing unnecessary p-type self-doping and high leakage current.More seriously,trap-induced non-radiative recombination from rapid crystallization causes into large energy loss with a low open circuit voltage.Therefore,the Sn-based solar cells have efficiency far behind the Pb-based solar cells.Herein,the polymer poly(ethylene glycol)diacrylate(PEGDA)is used to control crystal growth and passivate the defects in FA_(0.85)PEA_(0.15)SnI_(3) thin film.This Sn-perovskite layer shows compact crystal with large grain size and reduced defects.Optimized perovskite thin film is further processed to fabricate the inverted solar cell with device structure of ITO(indium tin oxide)/PEDOT:PSS(Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate))/FA_(0.85)PEA_(0.15)SnI_(3)/ICBA(indene-C60 bisadduct)/BCP(bathocuproine)/Ag,which shows the power conversion efficiency(PCE)of 11.45%with voltage of 0.82 V.Moreover,corresponding perovskite solar cells exhibit an enhanced stability due to PEGDA induced compressive strain in perovskite.This work could shed light on one of successful attempts to improve Sn-based solar cell efficiency for sustainable energy conversion.
文摘A highly efficient second-harmonic source is integrated into a silicon nitride microring resonator,unlocking the potential for advanced chip-scale devices such as miniaturized atomic clocks and fully integrated self-referenced microcombs.
基金supported in part by the Research Fund of State Grid Corporation of China(No.52183516000B)the National Natural Science Foundation of China(No.61475129)+1 种基金the Natural Science Foundation of Fujian Province(No.2017J06016)and the Fundamental Research Funds for the Central Universities(No.20720180057)
文摘We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/50 fiber loop mirror(FLM), a 10/90 FLM, and a piece of large-gain Tm-doped double-clad fiber pumped by a 793 nm laser diode. The 10/90 FLM is not only used as an output mirror, but also acts as a periodical saturable absorber for initiating DSR mode locking. The stable DSR pulses are generated at the center wavelength as long as 2080.4 nm, and the pulse duration can be tunable from 780 to 3240 ps as the pump power is increased. The maximum average output power is 1.27 W, corresponding to a pulse energy of 290 nJ and a nearly constant peak power of 93 W. This is, to the best of our knowledge, the longest wavelength for DSR operation in a mode-locked fiber laser.
基金National Natural Science Foundation of China(NSFC)(11674269,91750115)
文摘Raman and Brillouin lasers based on a high-quality(high-Q) whispering gallery mode microresonator(WGMR)are usually achieved by employing a tunable single-frequency laser as a pump source. Here, we experimentally demonstrate visible Raman and Brillouin lasers using a compact microresonator/ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN)-fiber hybrid system by incorporating a WGMR with a fiber-compatible distributed Bragg reflector/fiber Bragg grating to form a Fabry–Perot(F-P) fiber cavity and using a piece of Pr:ZBLAN fiber as gain medium.The high-Q silica-microsphere not only offers a Rayleigh-scattering-induced backreflection to form the ~635 nm red laser oscillation in the F-P fiber cavity, but also provides a nonlinear gain in the WGMR itself to generate either stimulated Raman scattering or stimulated Brillouin scattering. Up to six-order cascaded Raman lasers at0.65 μm, 0.67 μm, 0.69 μm, 0.71 μm, 0.73 μm, and 0.76 μm are achieved, respectively. Moreover, a Brillouin laser at 635.54 nm is clearly observed. This is, to the best of our knowledge, the first demonstration of visible microresonator-based lasers created by combining a Pr:ZBLAN fiber. This structure can effectively extend the laser wavelength in the WGMR to the visible waveband and may find potential applications in underwater communication, biomedical diagnosis, microwave generation, and spectroscopy.