By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found t...By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found that in area of presumptive cleavage furrow the scanning curve became ∨ shape, indicating dark stripe appeared in that place. Then the fluorescence intensity increased at the place where the botton of ∨ shape had located, and the scanning curve tuxned to ∧ shape, indicating single stripe was formed. While enhanced fluorescence appeared on the borders of ∧ shape, an M shape curve was found, show-ing double stripe occurred. During the distance between two borders of M shape incresing from 50 μm to 100μm,a fluorescence peak came to sight in the middle of the M shape, which being the cleavge furrow bottom. The two lateral sides of furrow bottom with decreasing fluorescence were nascent membrane. At that time the curve became W shape. By the sides of cleavage furrow the the stress folds became conspicous after double stripe stage, showing the stretching of the egg surface being increased. With our[31, 33] and others[32] reports that polylysine could induce the appearance of nascent membrane and phyto-hemagglutinins could decrease or prevent the appearance of nascent membrane, we believed the idea of Schroeder[25] that increasing mechanical stress could initiate nascent membrane formation and thought that the stress lay to the outsides of cleavage furrow.展开更多
High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been pai...High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been paid to find ways to reduce the phosphors＇ concentration and efficiency roll-off of PHOLEDs. In this work, we reported red emission PHOLEDs with low dopant concentration and low efficiency roll-off based on a novel host material 2,4-biscyanophenyl-6-（12-phenylindole[2,3-a]carbazole-ll-yl）-1,3,5-triazine （BCPICT）, with thermally activated delayed fluorescent （TADF） properties. The device with 1.0% dopant concentration displayed a maximum external quantum efficiency of 10.7%. When the dopant concentration was increased to 2.0%, the device displayed a maximum external quantum efficiency of 10.5% and a low efficiency roll-off of 5.7% at 1000 cd/m^2.展开更多
An optimized compound 9-(9,9-dimethylacridin-10(9 H)-yl)-6 H-benzo[c]ch-romen-6-one(MAB) was designed and synthesized based on our previously reported TADF emitter 6-(9,9-dimethylacridin-10(9 H)-yl)-3-methyl-1 H-isoch...An optimized compound 9-(9,9-dimethylacridin-10(9 H)-yl)-6 H-benzo[c]ch-romen-6-one(MAB) was designed and synthesized based on our previously reported TADF emitter 6-(9,9-dimethylacridin-10(9 H)-yl)-3-methyl-1 H-isochromen-1-one(MAC) to further improve the performance of thermally activated delayed fluorescence(TADF)emitters. With the additional phenyl in coumarin-contained plane, MAB possesses an extended distribution of the lowest unoccupied molecular orbitals(LUMO), and thus realizes reduced electron exchange between the frontier molecular orbitals and a stretched molecular dipole moment compared with MAC. MAB based organic light-emitting diode(OLED)exhibits a remarkable maximum external quantum efficiency(EQE) of 21.7%, which is much better than the maximum EQE of MAC-based OLED with a value of 12.8%. Our work proves that extending the distribution of LUMO is a simple but effective method to improve the efficiency of TADF emitter.展开更多
In this paper, the design of plasma swirler is presented in detail. The experiments were carded out to verify the feasibility of using plasma swirler to control diffusion flame. The plasma swider consists of multiple ...In this paper, the design of plasma swirler is presented in detail. The experiments were carded out to verify the feasibility of using plasma swirler to control diffusion flame. The plasma swider consists of multiple electrodes with staggered arrangement on both sides of combustor＇s expansion section. The plasma swirler can enhance combustion stability through ionizing the air to produce active free radical and promoting the swirling air. In the experiments, the flame response to the plasma swider was examined with OH distribution by planar laser induced fluorescence （PLIF）. The experimental results showed that the flame reaction zone was broadened with the increase of the plasma exciting, and this demonstrated that the plasma swirler could be used to control diffusion flame. The design of plasma swirler is feasible.展开更多
文摘By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found that in area of presumptive cleavage furrow the scanning curve became ∨ shape, indicating dark stripe appeared in that place. Then the fluorescence intensity increased at the place where the botton of ∨ shape had located, and the scanning curve tuxned to ∧ shape, indicating single stripe was formed. While enhanced fluorescence appeared on the borders of ∧ shape, an M shape curve was found, show-ing double stripe occurred. During the distance between two borders of M shape incresing from 50 μm to 100μm,a fluorescence peak came to sight in the middle of the M shape, which being the cleavge furrow bottom. The two lateral sides of furrow bottom with decreasing fluorescence were nascent membrane. At that time the curve became W shape. By the sides of cleavage furrow the the stress folds became conspicous after double stripe stage, showing the stretching of the egg surface being increased. With our[31, 33] and others[32] reports that polylysine could induce the appearance of nascent membrane and phyto-hemagglutinins could decrease or prevent the appearance of nascent membrane, we believed the idea of Schroeder[25] that increasing mechanical stress could initiate nascent membrane formation and thought that the stress lay to the outsides of cleavage furrow.
基金supported by the National Natural Science Foundation of China (51525304)the National Key Basic Research and Development Program of China (2015CB655002)
文摘High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been paid to find ways to reduce the phosphors＇ concentration and efficiency roll-off of PHOLEDs. In this work, we reported red emission PHOLEDs with low dopant concentration and low efficiency roll-off based on a novel host material 2,4-biscyanophenyl-6-（12-phenylindole[2,3-a]carbazole-ll-yl）-1,3,5-triazine （BCPICT）, with thermally activated delayed fluorescent （TADF） properties. The device with 1.0% dopant concentration displayed a maximum external quantum efficiency of 10.7%. When the dopant concentration was increased to 2.0%, the device displayed a maximum external quantum efficiency of 10.5% and a low efficiency roll-off of 5.7% at 1000 cd/m^2.
基金supported by the National Natural Science Foundation of China (51773029, 51533005 and 51373190)the National Key Research & Development Program of China (2016YFB0401002)+1 种基金Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the 111 Project and Qing Lan Project, China
文摘An optimized compound 9-(9,9-dimethylacridin-10(9 H)-yl)-6 H-benzo[c]ch-romen-6-one(MAB) was designed and synthesized based on our previously reported TADF emitter 6-(9,9-dimethylacridin-10(9 H)-yl)-3-methyl-1 H-isochromen-1-one(MAC) to further improve the performance of thermally activated delayed fluorescence(TADF)emitters. With the additional phenyl in coumarin-contained plane, MAB possesses an extended distribution of the lowest unoccupied molecular orbitals(LUMO), and thus realizes reduced electron exchange between the frontier molecular orbitals and a stretched molecular dipole moment compared with MAC. MAB based organic light-emitting diode(OLED)exhibits a remarkable maximum external quantum efficiency(EQE) of 21.7%, which is much better than the maximum EQE of MAC-based OLED with a value of 12.8%. Our work proves that extending the distribution of LUMO is a simple but effective method to improve the efficiency of TADF emitter.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51006104, 51076150 and 50906085)
文摘In this paper, the design of plasma swirler is presented in detail. The experiments were carded out to verify the feasibility of using plasma swirler to control diffusion flame. The plasma swider consists of multiple electrodes with staggered arrangement on both sides of combustor＇s expansion section. The plasma swirler can enhance combustion stability through ionizing the air to produce active free radical and promoting the swirling air. In the experiments, the flame response to the plasma swider was examined with OH distribution by planar laser induced fluorescence （PLIF）. The experimental results showed that the flame reaction zone was broadened with the increase of the plasma exciting, and this demonstrated that the plasma swirler could be used to control diffusion flame. The design of plasma swirler is feasible.
