最新刊期
卷 36 ， 期 9 ， 2015
- 摘要：Liquid-crystal molecule ((Z)-2-(4-aminophenyl)-3-(4-(dodecyloxy) phenyl)-acrylonitrile, CN-APHP) with strong fluorescence in the aggregation state was designed and synthesized. Ultraviolet absorption spectrum, fluorescence emission spectrum were used to study the photo physical property of the CN-APHP. Differential scanning calorimetry (DSC) and polarizing optical microscope (POM) were used to study the liquid crystal property of compound CN-APHP. The results indicate that a smectic liquid crystal is observed from 59 to 85 ℃. The ordered orientated film of CN-APHP shows obvious luminous anisotropy and the linear polarization is 0.3.关键词：α-cyanostilbene;optical properties;liquid crystal;anisotropy143|64|6更新时间：2020-08-12
- 摘要：AgInS2 quantum dots (QDs) were synthesized using hot colloidal method and transferred into water via a ligand exchange route. To enhance the stability of these QDs, dBSA was coated on the aqueous QDs as a ligand shell. After dBSA modification, a size increase was observed from the transmission electron microscopy (TEM) results. The prepared dBSA-MPA QDs exhibited good monodispersity, enhanced stability (stable for 4 weeks) and bright photoluminescence. Then the QDs were functionalized with folic acid (FA) and the successful conjugation was confirmed by the Fourier transform infrared (FT-IR) spectroscopy. The resulting FA-dBSA-MPA QDs nanocomposites were tested in breast cancer cells (MCF-7 cells) with elevated folate receptor expression. Compared to the unconju-gated dBSA-MPA QDs, the presence of FA on the surface of QDs significantly improved the uptake rate of the nanop-articles by the cancer cells.关键词：AgInS2;quantum dots;fluorescence;in vitro;cell imaging165|102|1更新时间：2020-08-12
- 摘要：AgInS2 Cu-doped nano-SnO2TiO2 gelatins were prepared and coated onto glass substrates by spin coating method, followed by drying at low temperature and calcined at high temperature. The films were characterized by XRD, SEM, EDS, and UV-Vis. The photocatalysis degradation efficiency was studied by using methyl orange as probe. XRD patterns show that the films are anatase structure. SEM images show that the surfaces of the films are flat without obvious crack, and the average diameter is about 20 nm. EDS results indicate that Cu has been introduced to SnO2/TiO2 films. UV-Vis absorption spectra show that the absorbance of Cu-doped SnO2/TiO2 films at visible region increase comparing to pure TiO2 film. The degradation experiment under UV light shows that the photocatalysis degradation efficiency of Cu-doped SnO2/TiO2 film is higher than that of pure TiO2 film. The photocatalysis degradation efficiency is the biggest when the doping mole fraction of Cu is 10%.关键词：sol-gel method;SnO2/TiO2film;Cu-doping;photocatalysis131|69|3更新时间：2020-08-12
- 摘要：Er3+/Yb3+ codoped oxyfluoride borosilicate glass ceramics were prepared by the traditional high temperature melt-quenching method and subsequent thermal treatment procedure and all the oxyfluoride glass ceramics were transparent. XRD results certified the formation of BaYF5 phase during the crystallization process. Under the excitation of 980 nm laser diode, strong green upconversion emissions were observed, which came from the transitions 2H11/2→4I15/2 and 4S3/2→4I15/2 of Er3+ ions. Based on the fluorescence intensity ratio(FIR) method, the temperature characteristic of green upconversion emission was investigated and the maximum sensitivity was 0.003 4 K-1 at 523 K. The experiment results indicate that the upconversion luminescence of Er3+/Yb3+ co-doped oxyfluoride borosilicate glass ceramics is promising for the application as optical temperature sensors with high accuracy.关键词：upconversion luminescence;Er3+;oxyfluoride glass ceramic;temperature sensor151|83|4更新时间：2020-08-12
- 摘要：YVO4:Tm3+ nanophosphors were synthesized by solvothermal method. X-ray diffraction (XRD), transmission electron microscope (TEM), ultraviolet analyzer, ultraviolet-visible (UV-Vis) absorption spectra, and photoluminescence (PL) spectra were used to characterize and analyze the nanophosphors. The experiment results show that YVO4:Tm3+ nanophosphors have bright blue light emission with high color purity and luminescence intensity, and have good thermal stability properties. Therefore, YVO4:Tm3+ nanophosphors are very suitable phosphors for field emission display.关键词：solvothermal method;YVO4:Tm3+;nanophosphors;field emission display114|90|1更新时间：2020-08-12
- 摘要：On the basis of field emission characteristics of nano-diamond, the field emission characteristics of diamond doped CNTs were studied. The composite coating of diamond and CNTs was formed using electrophoretic deposition, and the cathode samples were fabricated after heat treatment. The microstructure, field emission and luminescence performance of the samples were characterized. Compared with the undoped diamond cathode, the turn-on field of the composite coating cathode decreases obviously, the field emission current increases. The fluorescent powder on the anode surface can luminescent under lower electric field, but the luminescence is nonuniform and the phenomena of ‘edge luminescence’ occurs. The improvement of the field emission characteristics is due the enhancement of the electron transportation capacity of the composite coating and the increase of the effective emitter number. Finally, the reasons of ‘edge luminescence’ were explained.关键词：nano-diamond;CNTs;field emission;electrophoresis deposition109|107|3更新时间：2020-08-12
- 摘要：A high brightness and high power fiber coupling laser module with single diode laser (LD) was designed and fabricated. The wavelength of GaAs semiconductor laser is 975 nm and power is 10W. The numerical aperture of the fiber is 0.18 and the core diameter is 105μm. When the drive current is 10A, 9.37W output power is obtained from the fiber, the coupling efficiency is 94.3% , and the brightness is 1.64MW/(cm2·str).关键词：semiconductor laser;fiber coupling;brightness117|187|7更新时间：2020-08-12
- 摘要：Blue organic light-emitting devices with periodic doped Ir(ppz)3 emission layers were investigated. It effectively inhibited the drift of emission zone, reduced roll-off of efficiency caused by quenching and enhanced the spectral stability. Meanwhile, it enhanced excitation mechanisms of self-recombination by carrier trapping of FIrpic in Ir(ppz)3, improved the utilization rate of carriers and efficiency of devices and reduced the leakage of carriers to electrode. Compared with traditional device, the maximal current efficiency and maximal power efficiency were improved from 16.55 cd/A to 20.71 cd/A and from 14.85 lm/W to 16.26 lm/W, respectively, and the efficiency roll-off was improved 40%.关键词：blue organic light-emitting device;roll-off of efficiency;spectral stability;self-recombination107|285|0更新时间：2020-08-12
- 摘要：ITO anode was modified utilizing UV-ozone or plasma technique and applied to fabricate single-layer organic light-emitting devices (SLOLEDs). The effects of the two methods on the device performance were researched. The experiment results indicate that the devices with plasma modifying manifest better performance than the devices with UV-ozone modifying. Based on plasma technique, further, two sort of buffer material MoO3 and HAT-CN were introduced to fabricate SLOLEDs. As a result, the devices using HAT-CN as buffer material denote better performance.关键词：organic light-emitting device;anode modification;single-layer97|133|0更新时间：2020-08-12
- 摘要：The effects of i-GaN and p-GaN layer thickness on the spectral response of back-illuminated and front-illuminated GaN p-i-n structure ultraviolet photodetectors were investigated by theory calculation. For the back-illuminated p-i-n photodetectors, the device quantum efficiency can be improved by both suitably decreasing the thickness of i-GaN layer and increasing the thickness of p-GaN layer, and the Ohmic contact property of p-GaN has not obvious influence on the device responsivity. The quantum efficiency of photodetector can be improved by reducing the background carrier concentration of i-GaN layer. The results are different for the front-illuminated p-i-n photodetectors. it is found that the device quantum efficiency can be improved by both properly increasing the thickness of i-GaN layer and decreasing the thickness of p-GaN layer, and the excellent Ohmic contact property of p-GaN is very important for the front-illuminated p-i-n hotodector. The opposite design method of i-GaN and p-GaN layer for the two photodetectors are mainly attributed to the different energy band and photon absorption.关键词：GaN;p-i-n structure;ultraviolet photodetector;quantum efficiency143|97|3更新时间：2020-08-12
- 摘要：In order to enhance the non-chain DF laser output energy and electro-optic conversion efficiency, the electrostatic field distribution of Chang electrode and flat electrode which was consisted by rough cathode and smooth anode was calculated by finite element method. For Chang electrode, the higher electric field of spark-pin was introduced, and the electrostatic field distribution of spark-pin UV pre-ionization was calculated. For the flat electrode, the electrostatic field distribution of burr on the cathode surface was calculated. The burrs on the cathode surface can form a series of higher electric field, but cant lead to uniformity of plate electrode field deteriorating. And then, pulsed discharge experiments were carried out on two kinds of electrodes, so discharging performance and output characteristics of non-chain pulsed DF laser were obtained. The discharge experiment results show that the uniform electric field is conducive to increase the output energy of non-chain pulsed DF laser. It is also verified that the higher electric field of the burrs on the cathode of self-initiated discharge DF laser is benefit to volume discharge. Besides, the self-initiated discharge is more applicable for large volume discharge.关键词：lasers;electric field analysis;finite element simulation;output characteristic119|148|4更新时间：2020-08-12
- 摘要：An integrated perovskite/organic bulk-heterojunction (BHJ) photovoltaic device was fabricated for efficient light harvesting and energy conversion. The structure of the solar cells consists of two photovoltaic layers, namely a methylammonium lead iodide (CH3NH3PbI3) and poly(3-hexylthiophene) (P3HT) blended with methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM) organic BHJ active layer. The power conversion efficiency (PCE) of 6.54% was achieved in the integrated device with a Jsc of 19.14 mA/cm2, a Voc of 0.76V, and a FF of 45.0%. Compared to that of CH3NH3PbI3/PCBM planar device, the enhanced performance indicates that the BHJ film absorbs light and contributes to the current density of the device. Our research further demonstrates the compatibility and synergistic potential of the perovskite and organic bulk-heterojunction (BHJ) photovoltaic device.关键词：perovskite;bulk heterojunction;integrated solar cells121|165|0更新时间：2020-08-12
- 摘要：Efficiency and its roll-off are improved by using double electron transport layers (DETLs) in organic light-emitting diodes (OLEDs). When DETLs of Bphen/BCP are employed, device efficiency is enhanced by 10% compared to the device with single Bphen as an electron transport layer (ETL) because of lower hole leakage current. Meanwhile, due to more electrons injected, efficiency roll-off of 0% is observed for the Bphen/BCP-based device with the increase of current density from 50 to 600 mA/cm2. On the contrast, the device with single BCP as ETL has an efficiency roll-off of 16%, which is reduced from 2.5cd/A at 50 mA/cm2 to 2.1cd/A at 300mA/cm2. Compared to the Cs2CO3:BCP-ETL-based device with an efficiency roll-off of 30% from 50 to 300 mA/cm2, device efficiency is declined by 0% within the range from 50 to 600 mA/cm2 as DETLs of Bphen/Cs2CO3:BCP are explored. The reason is the blocking of Cs atom interdiffusion into the emissive layer by the Bphen of Bphen/Cs2CO3:BCP.关键词：luminous efficiency;efficiency roll-off;electron transport layer;leakage current108|103|5更新时间：2020-08-12
- 摘要：Organic microcavity structures were designed and fabricated with distributed Bragg reflector as the mirror and Alq:DCJTI host-guest doping system as the gain medium. The standing wave field within microcavity was simulated by using the transfer matrix method, and a suitable microcavity structure was determined. The lasing properties of the microcavity laser were studied by a UV pulse laser. The output wavelength of the microcavity laser is 650 nm. An obvious lasing behavior was observed with a threshold intensity of 110W·cm-2. FWHM was narrowed from 4.7 to 3.2nm before and after the threshold.关键词：organic film;optical microcavity;lasing129|209|2更新时间：2020-08-12
- 摘要：Based on surface enhanced Raman scattering (SERS), a super-sensitive immunoassay of prostate specific antigen (PSA) was developed with the sandwich-type structure consisted of the nano-Ag immune probes and nano-Ag immune substrate. Experimentally, the chemical reduction method was used to prepare Au and Ag nanoparticles, the nano-Au/Ag immune probes were prepared by immobilising Raman reporter molecule 4-mercaptobenzoic acid (4-MBA) and anti-prostate specific antigen antibody (Anti-PSA) onto the surfaces of Au/Ag nanoparticles. The nano-Ag/Au immune substrates were prepared by in-situ growing of Ag/Au nanoparticles on a silicon wafer and linking with Anti-PSA. The immunoassays of PSA were explored by the four kinds of sandwich-type structures consisted of the nano-Au/Ag immune probes and nano-Au/Ag immune substrates, respectively. It is found that the sandwich-type structure consisted of nano-Ag immune probe and nano-Ag immune substrate is the best one to the immunoassay of PSA, and the detection limit of PSA is as low as 1.8 fg/mL (3.490×10-18mol/L), which is suitable to be applied in early detection and diagnosis of prostate cancer.关键词：surface-enhanced Raman scattering;nano-immune probe;nano-immune substrate;immunoassay142|119|8更新时间：2020-08-12
- 摘要：To resolve the problem of poor color performance of liquid crystal display, the main factors which affect the color gamut were researched from the principle. The affects of the color filter thickness, LED light source spectrum and quantum dot materials were verified by experiments. The color gamut is increased 8% by thickening the color filter and raised to more than 85% NTSC by changing the LED light source spectrum. By using quantum dot material, the color gamut raises to more than 100% NTSC.关键词：liquid crystal display;wide color gamut;light emitting diode;quantum dot253|537|7更新时间：2020-08-12
- 摘要：In order to realize the quick start-up of fiber optic gyroscope, the start-up model of the superluminescent light emitting diodes (SLD) was established by analyzing the change principle of drive current and temperature in SLD after power on, and the factors affecting the start-up time of SLD were got. By using high-speed data acquisition card, the start-up time of SLD was measured to be 3-4 s at room temperature, the power fluctuation error was 4.5%, and the wavelength drift was 0.92nm caused by the temperature control system. The experiment results were consistent with the theoretical model established. The methods to reduce the start-up time of SLD and realize the quick start-up of fiber optic gyroscope were proposed in theoretically.关键词：start-up model;SLD;temperature;output power;wavelength119|131|3更新时间：2020-08-12
- 摘要：By combining the simulation program 4D-MCLCSS of laser Compton scattering and the package of Geant4, the gamma rays generation of Shanghai laser-electron gamma source and its impact on the photo-transmutation process of the long-lived fission products 126Sn was simulated. The dependency of transmutation ratio and the geometry parameters of transmutation target was researched, and the transmutation product distribution based on SLEGS was initially diagnosed. It is shown that the best target thickness and the best radius to obtain the transmutation target of 126Sn are respectively 16 cm and 0.4cm, and the corresponding transmutation rate is 1.89×106/s. The research results show that the light photo-transmutation rate based on SLEGS is twice higher than the laser-driven bremsstrahlung, and its upgrade potential is huge.关键词：photo-transmutation;SLEGS;126Sn;Geant4112|97|0更新时间：2020-08-12
- 摘要：A nonlinear approach of controlling the illumination of a mixed white LED system was proposed. This LED system is made up of a warm color LED source and a cool color LED source. The overall illumination of the LED system is due to the combined emitted flux of both LED source. With reasonable approximation, the proposed theoretical models with three-dimensional conditions are simplified into practical solutions, which aim at providing a comprehensive LED system theory with physical explanations for electronics engineers and researchers working in LED system designs. The proposed model consists of simple process of optical and electrical measurements, which are easy for LED device manufactures and system designers to follow. The proposed method has been tested with mixed white LED system. The theoretical results are reasonably in good agreement with measured values. The idea is applicable to LED system with multiple sources and is not limited to white LEDs.关键词：mixed white;light-emitting diode;illumination model;three-dimensional(3D)conditions107|110|0更新时间：2020-08-12
- 摘要：For the varied line-space (VLS) grating used in the region of 50-150 nm, the spherical wave exposure system was used for the optimization design, and the groove density and spectra resolution of the different width grating were analyzed. The theory resolution ability is higher than 14000 when the grating width is 4mm in the use of wavelength range, about 9000 when the grating width is 10mm, and about 3000 when the grating width is 30mm, respectively. The bigger the grating width is, the bigger the bending degree of groove is, and the lower the spectral resolution ability is. Therefore, spherical wave exposure system is only suitable for making the VLS grating with smaller width.关键词：varied-line-space grating;spherical wavefront;groove density;spectral resolution126|253|5更新时间：2020-08-12
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