This paper is concerned with developing a novel distributed Kalman filtering algorithm over wireless sensor networks based on randomized consensus strategy. Compared with centralized algorithm, distributed filtering t...
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Quantum dots have innate advantages as the key component of optoelectronic devices. For white light-emitting diodes (WLEDs), the modulation of the spectrum and color of the device often involves various quantum dots o...
Quantum dots have innate advantages as the key component of optoelectronic devices. For white light-emitting diodes (WLEDs), the modulation of the spectrum and color of the device often involves various quantum dots of different emission wavelengths. Here, we fabricate a series of carbon quantum dots (CQDs) through a scalable acid reagent engineering strategy. The growing electron-withdrawing groups on the surface of CQDs that originated from acid reagents boost their photoluminescence wavelength red shift and raise their particle sizes, elucidating the quantum size effect. These CQDs emit bright and remarkably stable full-color fluorescence ranging from blue to red light and even white light. Full-color emissive polymer films and all types of high-color rendering index WLEDs are synthesized by mixing multiple kinds of CQDs in appropriate ratios. The universal electron-donating/withdrawing group engineering approach for synthesizing tunable emissive CQDs will facilitate the progress of carbon-based luminescent materials for manufacturing forward-looking films and devices.
A series of single-composition emission-tunable CdWO4:Eu^3+ uniform size nanorods were synthesized by polyvinylpyrrolidone(PVP) assisted hydrothermal process. The products were measured by powder X-ray diffraction...
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A series of single-composition emission-tunable CdWO4:Eu^3+ uniform size nanorods were synthesized by polyvinylpyrrolidone(PVP) assisted hydrothermal process. The products were measured by powder X-ray diffraction(PXRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), photoluminescence, and fluorescent decay test. The results showed that reaction time, temperature, p H values and Eu^3+ doped concentration played important roles in determining the morphologies and photoluminescent properties. And we also investigated its use in Ga N LED, warm-white-light could be obtained by the combination of the bright blue light originated from the charge transfer transition in the tungstate groups and the near UV light from LED chip with the red emission from 4f-4f transition of Eu^3+, respectively. By properly tuning the doping concentration of Eu^3+, chromaticity coordinates(0.30 0.22) could be achieved under the 380 nm excitation and its color rendering index was 80.6. So it has potential application in warm-WLED and replacing the commercial YAG:Ce phosphor which absence of red band emission.
The flexible organic light emitting diodes (OLEDs) has attracted a lot of attention because of its very wide and promising application prospect. The flexible encapsulation is a most problem for mass production of flex...
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The flexible organic light emitting diodes (OLEDs) has attracted a lot of attention because of its very wide and promising application prospect. The flexible encapsulation is a most problem for mass production of flexible OLEDs since their sensitivity to water and oxygen. Traditional flexible encapsulation using plasma enhanced chemical vapor deposition (PECVD) film as the inorganic layer. However owing to the complicated pattern of sub-layer and particles, the poor step coverage of PECVD film results in bad encapsulation properties. Therefore the plasma enhanced atomic layer deposition (PEALD) is studied on account of its better step coverage and lower growth temperature. Firstly, the PECVD SiNx process has been researched to achieve the low water vapor transmission rate (WVTR) (WVTR<5*10-4g m-2day-1) and low stress (<-300MPa). Then we design several flexible encapsulation films with multilayer structures. The PEALD SiOx film is critical in the multilayer encapsulation films to obtain flexible OLED devices with the best air-stability . Through evaluation of the pass rate after 60oC 90% RH and 85 oC 85% RH for 240h, best structure of flexible encapsulation films has been selected and used in our product.
This paper we investigates the problem of stability and bifurcation of fractional-order financial system time-delay via the Lyapunov stability judgment method and application of impulse control method. Finally, a nume...
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This paper we investigates the problem of stability and bifurcation of fractional-order financial system time-delay via the Lyapunov stability judgment method and application of impulse control method. Finally, a numerical simulation example is provided to verify the effectiveness and the benefit of the proposed stability and bifurcation criterion.
We demonstrate high-brightness blue organic light emitting diodes(OLEDs) using two types of guest-host systems. A series of blue OLEDs were fabricated using three organic emitters of dibenz anthracene(perylene), di(4-...
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We demonstrate high-brightness blue organic light emitting diodes(OLEDs) using two types of guest-host systems. A series of blue OLEDs were fabricated using three organic emitters of dibenz anthracene(perylene), di(4-fluorophenyl) amino-di(styryl) biphenyl(DSB) and 4,4'-bis[2-(9-ethyl-3-carbazolyl)vinyl]biphenyl(BCzV Bi) doped into two hosting materials of 4,4'-bis(9-carbazolyl) biphenyl(CBP) and 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole(PBD) as blue emitting layers, respectively. We achieve three kinds of devices with colors of deep-blue, pure-blue and sky-blue with the Commission Internationale de L'Eclairage(CIE) coordinates of(0.16, 0.10),(0.15, 0.15) and(0.17, 0.24), respectively, by employing PBD as host material. In addition, we present a microcavity device using the PBD guest-host system and achieve high-purity blue devices with narrowed spectrum.
The organic/inorganic hybrid barriers were fabricated to encapsulate the organic light-emitting ***2O3 as inorganic layer was deposited by atomic layer deposition(ALD)and polydimethoxysilane(PDMS)as organic layer was ...
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The organic/inorganic hybrid barriers were fabricated to encapsulate the organic light-emitting ***2O3 as inorganic layer was deposited by atomic layer deposition(ALD)and polydimethoxysilane(PDMS)as organic layer was prepared by the spin-coating *** was found that the optimized encapsulation structure with a prior planarization process had a better barrier performance with a lower water vapor transmission rate improved effectively from 4.95 × 10-1 gm-2 day-1 of Al2O3/PDMS films to 7.30 × 10-3 gm-2 day-1 of the hybrid PDMS/Al2O3/PDMS films at 60℃ and a relative humidity of 90%and a longer luminance decay *** improvements were attributed to the surface planarization of encapsulation basement including the coverage of particles by the prior spin-coating process,reducing the defects of inorganic film in process,and the hydrophobic surface of the outermost polymer lowering the adsorption of water vapor.
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