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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • sodium lighting system
  • modeling
  • radiation curves
  • LED lighting system
  • software goniophotometer
  • upper half-space
应用领域
  • Electrical Engineering and Automation
机构单位
  • VSB-TU Ostrava
91 条数据
?? 中文（中国） ▾

  • AIP Conference Proceedings [Author(s) SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems - Santiago, Chile (26–29 September 2017)] - Sensitivity study on the off-ideal design and off-design operation of tubular solar receivers

    摘要： Based on the optimum heat transfer conditions for tubular type high-temperature solar receivers using Sodium and Carbonate salt (Li2CO3 -Na2CO3-K2CO3), sensitivity studies on off-ideal design and off-design operation of the receivers were investigated. Off-ideal design applying non-ideal turbulence caused significant effect on the Carbonate salt receiver resulting in large efficiency decrease due to its high viscosity. Conservative receiver design with milder solar flux (allowing up to 30% marginal acceptable stress) created less than 3 % (in absolute receiver efficiency) efficiency decrease for both fluids. Degree of efficiency change under off-design (up to 40 % part load in solar input) operation showed around 10 % decrease in absolute efficiency. Analysis with non-ideal flux distribution revealed that local flux limit defined by the ideal condition can still be applicable even the real flux distribution is different from the ideal design condition.

    关键词： solar receivers,Sodium,off-ideal design,off-design operation,Carbonate salt,sensitivity study

    更新于2025-09-04 15:30:14

  • Combined treatment of sodium ferulate, <i>n</i> -butylidenephthalide, and ADSCs rehabilitates neurovascular?unit in rats after photothrombotic stroke

    摘要： The remodelling of structural and functional neurovascular unit (NVU) becomes a central therapeutic strategy after cerebral ischaemic stroke. In the present study, we investigated the effect of combined therapy of sodium ferulate (SF), n‐butylidenephthalide (BP) and adipose‐derived stromal cells (ADSCs) to ameliorate the injured NVU in the photochemically induced thrombotic stroke in rats. After solely or combined treatment, the neovascularization, activation of astrocytes, neurogenesis, expressions of vascular endothelial growth factor (VEGF) and claudin‐5 were assessed by immunohistochemical or immunofluorescence staining. In order to uncover the underlying mechanism of therapeutic effect, signalling of protein kinase B/mammalian target of rapamycin (AKT/mTOR), extracellular signal‐regulated kinase 1/2 (ERK1/2), and Notch1 in infarct zone were analysed by western blot. 18F‐2‐deoxy‐glucose/positron emission tomography, magnetic resonance imaging, Evans blue staining were employed to evaluate the glucose metabolism, cerebral blood flow (CBF), and brain‐blood barrier (BBB) permeability, respectively. The results showed that combined treatment increased the neovascularization, neurogenesis, and VEGF secretion, modulated the astrocyte activation, enhanced the regional CBF, and glucose metabolism, as well as reduced BBB permeability and promoted claudin‐5 expression, indicating the restoration of structure and function of NVU. The activation of ERK1/2 and Notch1 pathways and inhibition of AKT/mTOR pathway might be involved in the therapeutic mechanism. In summary, we have demonstrated that combined ADSCs with SF and BP, targeting the NVU remodelling, is a potential treatment for ischaemic stroke. These results may provide valuable information for developing future combined cellular and pharmacological therapeutic strategy for ischaemic stroke.

    关键词： adipose-derived stromal cells,n-butylidenephthalide,rehabilitation,sodium ferulate,neurovascular unit

    更新于2025-09-04 15:30:14

  • AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON CURRENT PROGRESS IN MATHEMATICS AND SCIENCES 2017 (ISCPMS2017) - Bali, Indonesia (26–27 July 2017)] - Synthesis and photocatalytic activity of nanocomposite based on sodium alginate from brown algae with ZnO impregnation

    摘要： The objective of this research is to synthesize nano sodium alginate-ZnO nanocomposite as photocatalyst to degrade methylene blue compounds. The successful synthesis of nano sodium alginate-ZnO nanocomposite was supported by the characterization of XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscope) and TEM (Tunneling Electron Microscope). The first stage of the research was the synthesis of nano sodium alginate with particle size 140 nm and crystallinity index 38.78 % by XRD and TEM characterization, the obtained particle size was 146 nm x 61 nm. Nano ZnO particle size 38 nm, by XRD and TEM characterization the obtained particle size was 56.6 nm x 33.3 nm. The next stage of nanocomposite synthesis of nano sodium alginate was the impregnation with nano ZnO particle size 130 nm, by XRD and TEM characterization the particle size was 228.0 nm x 134.2 nm. The success was also supported by FTIR and SEM characterization. The final stage was the degradation of blue methylene using nano-sodium alginate-ZnO nanocomposite. The highest degradation percentage by nano sodium alginate-ZnO nanocomposite with zinc nitrate concentration of 0.075 M was 51.68% with the first order rate constant of 9.5 x10-3 /min.

    关键词： methylene blue,nano ZnO,degradation,nanocomposite,nano sodium alginate

    更新于2025-09-04 15:30:14

  • Baking soda: an ultra-cheap and air stable electron injection layer for organic electronic devices

    摘要： To realize high performance printed organic optoelectronic devices, the development of air-stable, cheap, and solution-processable electron injection layers (EILs) is urgently required to avoid the use of a low work-function metal electrode with poor air stability. We report sodium bicarbonate (baking soda, NaHCO3) as an efficient, low-cost, air-stable, and environmentally friendly EIL material in various printed organic electronic devices including organic solar cells (OSCs), organic light-emitting diodes (OLEDs), organic photodiodes (OPDs) and n-channel organic thin film transistors (OFETs). UV photoelectron spectroscopy results indicated that the work-function of various common electrodes used for organic devices such as ITO, Au, Al and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) decreased significantly by more than 1 eV following deposition of a thin NaHCO3 film. The performance and stability of these organic devices improved by around 15% overall with ultra-cheap, air stable EILs. In particular, high performance OSCs based on PTB7:PC71BM with a power conversion efficiency of 8.40% and solution processed OLEDs based on PVK:PBD:Ir(ppy)3 with light emitting efficiencies of 68.5 cd A?1 and 20 lm A?1 were achieved by applying a NaHCO3 interlayer.

    关键词： air-stable,sodium bicarbonate,organic electronic devices,electron injection layers,baking soda,low-cost,solution-processable

    更新于2025-09-04 15:30:14

  • Influence of the Conditions of the Chemical Bath Deposition of Thin ZnSe Films on Their Morphology and Internal Mechanical Stresses

    摘要： ZnSe films up to 2300 nm thick on glass-ceramic supports were prepared by chemical bath deposition in the ZnCl2–Na2EDTA–NaOH–NH2OH·HCl system using sodium selenosulfate as a chalcogenizer. The reflections observed in the X-ray diffraction patterns correspond to the ZnSe (stilleite) phase of cubic (space group F43m) structure with a = 5.610 ± 0.002 ?. As shown by electron-microscopic examination, ZnSe films consist of globular formations tightly adjoining to each other with the mean size of 250–400 nm depending on the deposition conditions. Elemental EDX analysis shows that the films contain, on the average, 43.68 at. % Zn, 30.50 at. % Se, and 25.82 at. % O, with the oxygen concentration somewhat decreasing at a depth of 30 nm. The internal mechanical compression stresses caused by the difference in the thermal expansion coefficients of the ZnSe film and glass-ceramic support were calculated; these stresses depend on the film thickness and at ~1040 nm reach –30.62 kN m–2. The results obtained make it possible to exclude film discontinuities, which can appear with increasing film thickness in preparation of precursor layers, and to choose the optimum support material.

    关键词： chemical bath deposition,microstructure,internal mechanical stresses,film morphology,zinc selenide,films,sodium selenosulfate

    更新于2025-09-04 15:30:14

  • Effect of Er3+ on NaSrB glass: thermoluminescence and structural analysis

    摘要： The present work reports the investigations on Er3+-doped sodium–strontium–borate glasses for their structural, optical and thermoluminescence (TL) properties. While the amorphous nature of the prepared glasses is confirmed by the powdered X-ray diffraction (XRD), some interesting features were found in the structure and Fourier-transform infrared (FTIR) studies such as the nanocrystallization and the presence of BO3 and BO4 structural units. Some physical parameters such as ion concentration, polaron radius, inter-nuclear distance, and field strength are calculated and analyzed. Optical band gap was found to be sensitive to the concentration of the dopants. TL glow curve exhibits a single peak but it shifts with variation in concentration of Er2O3. Calculation of kinetic parameters show that the prepared glasses exhibit second-order kinetics. The effective atomic number (Zeff) of prepared glasses is also calculated which indicates their suitability for application in radiation dosimetry.

    关键词： thermoluminescence,sodium–strontium–borate glasses,optical properties,radiation dosimetry,Er3+-doped,structural analysis

    更新于2025-09-04 15:30:14

  • Improvement of photocatalyst properties of magnetic NPs by new anionic surfactant

    摘要： In this research, Fe3O4 NPs was synthesized by co- precipitation approach. Then SiO2 shell was grown on the Fe3O4 core. Synthesized NPs were characterized by means of XRD, FTIR, VSM, TGA, SEM and TEM. The magnetic properties of core and core-shell NPs was 74 and 42 emu/g, respectively. The TEM picture of core-shell was showed thickness shell of SiO2 on the Fe3O4 NPs. The size of this shell about 2.5nmWhich caused the core magnetic property to be well preserved. Photocatalyst activity of the synthesized NPs was investigated by using methyl orange (MO) and methylene blue (MB) as pollutant at different pH. For first time sodium citrate was used to improvement photo- degradation. The Fe3O4 indicated good photocatalyst activity for photo-degradation and it’s activity was considerably increased after SiO2 shell growth.

    关键词： Fe3O4@SiO2,Photocatalyst,Tri sodium citrate,Fe3O4,Anionic surfactant

    更新于2025-09-04 15:30:14

  • Effet de l’interaction lumiere-salinite sur l’activite du photosysteme ii des feuilles excisees de ma?s

    摘要： The decline in growth observed in many plants, subjected to salt stress and exposed to sunlight conditions, is often associated with a decrease in their photosynthetic activity. No clear mechanisms of the inhibited photosynthesis have emerged since photosystem II (PS II) is considered to play a key role in the response of leaf photosynthesis to environmental perturbations. The combination of light and salt stress appears to have synergistic effects on the photochemical activity of PSII driving, and to photoinhibition. The objective of this study was to evaluate the reversible effect of salinity and light interaction on maximal quantum efficiency of photosystem II (Fv/Fm.). In this experiment, detached leaves of two forage maize (Zea mays L.) varieties, Aristo and Arper were placed during 6 hours in solutions of different concentrations of NaCl (0, 100, 200 and 300 mM) and subjected to light (1000 μmol m-2 s-1) or obscurity. Then, their contents of sodium were determined. In order to verify the photo-inhibition reversibility, other leaves which were incubated in a solution of 300 Mm NaCl, during 4 hours were transferred in distilled water and also subjected to light or to obscurity. Results indicate that leaves which had been put to absorb NaCl in obscurity showed no change in maximal efficiency of PSII (Fv/Fm). Nevertheless, light treatment associated with salinity generates a photo-inhibition of PSII manifested by a significant decrease in maximal efficiency of PSII. This photo-inhibition, due to an excessive accumulation of sodium in leaves, is reversible. It is quite sufficient to eliminate only one factor of the association light-salinity for the PSII activity resume.

    关键词： Light stress,sodium chloride,Zea mays

    更新于2025-09-04 15:30:14

  • Optical, dielectric properties and thermal analysis on sodium sulfanilate dihydrate nonlinear optical single crystal

    摘要： Nonlinear optical sodium sulfanilate dihydrate (SSD) single crystal was grown by slow evaporation solution method at ambient temperature. Unit cell parameters were elucidated with the study of single crystal X-ray diffraction. Fourier transform infrared spectroscopic analyses were performed to indentify a variety of functional groups present in the grown SSD crystal. The level of optical transmittance of the grown SSD crystal was investigated by UV–Vis–NIR spectral analysis. The lower cut off wavelength of the grown crystal was observed at 243 nm and the band gap energy is found to be 5.23 eV. The spectral study of photoluminescence was carried out for the grown crystal which shows a sharp emission peak at 485 nm resulting blue–green emission that is suitable for the optical communication applications. Mechanical strength was measured by utilizing Vickers microhardness test and the value of n is found to be 2.25 asserting that the crystal belongs to soft material category. The dielectric properties were studied as a function of frequency at various temperatures and also the grown SSD crystal has been correlated with electro-optic properties. Thermogravimetric analysis was undertaken by a thermal analyzer with the temperature starting from 30 to 800 °C and TGA/DTA results show that the crystal has good thermal stability and useful for laser applications. Etching analysis also was performed for the grown SSD single crystal proving that it has good crystalline nature with fewer defects.

    关键词： Thermal analysis,Sodium sulfanilate dihydrate,Nonlinear optical materials,Dielectric properties,Optical properties,Crystal growth

    更新于2025-09-04 15:30:14

  • Ionic conductive and dielectric properties of samarium isovalent doping in non-stoichiometric bismuth sodium titanate perovskite

    摘要： Oxide ion-conducting solid electrolytes are of considerable importance as fuel cell component. Recently, Bi0.5Na0.5TiO3 (BNT)-based perovskite-structured oxides become a new hotspot of solid electrolyte since it has potential in oxygen ion conduction. Considerable ionic conductivity is achieved in a Bi deficient or an acceptor doping composition. In this work, the role of Sm content without lone pair electrons substituted for isovalent Bi is studied on the electrical properties of non-stoichiometric (Bi0.45Ca0.04)Na0.5TiO2.965 (BCNT). In the solid solution range, a transformation from resistive BCNT to dominated oxide ionic conductive process is revealed despite no additional designed vacancies involved. Interestingly, employment of smaller Sm cations by doping favors the plateau formation of dielectric permittivity at higher frequencies. Lone pairs substitution conception and shrinkage of lattice parameters are proposed to be responsible for the anomalous dielectric relaxation.

    关键词： Bismuth sodium titanate,Lead free,Oxide ion conductors,Dielectrics

    更新于2025-09-04 15:30:14