最新刊期
卷 39 ， 期 4 ， 2018
- 摘要：Rare earth organic complexes exhibit excellent luminescent properties. However, the inherent shortcomings like low stability and poor processability severely limit their practical applications. Ionic liquids (ILs) exhibit good stability and solubility, and the combination of ILs with rare earth organic complexes can overcome the abovementioned shortcomings and can afford the complexes more excellent properties as well as enhanced practicability. This paper presents several typical rare earth complexes/ILs luminescent materials as well as the status of ILs in the materials, and the future applications of these materials are also prospected.关键词：lanthanide;ionic liquids;hybrid material;antenna effect;luminescence297|385|12更新时间：2020-08-12
- 摘要：A microchannel reactor for rapid and efficient synthesis of high-quality inorganic perovskite quantum dot (CsPbBr3) was proposed. By adjusting the concentration and flow rate of the precursor solution, the fluorescence spectrum can be green to blue and the corresponding wavelength is from 515 nm to 464 nm. The CsPbBr3 NCs applied with red phosphor on a blue chip achieved a luminous efficacy of 62.93 lm/W under 20 mA current. The high efficient white LEDs demonstrated the promising potential of CsPbX3 NCs for low-cost display, lighting, and optical communication applications.关键词：microchannel reactor;inorganic perovskite quantum dots;white light LED182|241|6更新时间：2020-08-12
- 摘要：Tm3+/Yb3+ droped YNbO4 power sample was prepared with the molar ratios of 50Nb2O5-(46-x)Y2O3-4Yb2O3-xTm2O3 (x=0.1, 0.2, 0.5, 1, 2) by the high temperature solid state method at 1 300℃. Under 980 nm laser excitation, the upconversion luminescence spectra of samples show 478 nm from 1G4→3H6 transition of Tm3+ ions, 645 nm attributed to 1G4→3F4 transition of Tm3+ ions, respectively, and 707 nm emissions assigned to 3F3→3H6 transition of Tm3+ ions. The transition process is estimated by using the relation between the upconversion power and the operating current of the 980 nm laser. The numbers of photons absorbed are 2.72, 2.69 and 2.01. The first two correspond to three-photon absorption processes, and the last one corresponds to two-photon absorption process. The spectral properties of the samples are studied by using Judd-Ofelt theory. Spectral strength parameters Ωt(t=2,4,6) were computed based on the absorption peak's area of the absorption spectrum. The theoretical oscillator strength and the experimental oscillator strength were calculated according to the spectrum strength parameters,and the root mean square deviation (δrms) was 1.299×10-7. The transition probability, branching ratio and other parameters of the lower level transition of Tm3+ ion were calculated. The results show that:(1) the 3F4 has a longer level lifetime, which is suitable for up-conversion intermediate level; (2)3H5 has a longer level lifetime, and the transition branching ratio of 3H5→3H6 is close to 100%(96.46%), so this sample can be used to generate 1 216 nm laser.关键词：Tm3+;YNbO4;up conversion luminescence;J-O theory122|116|2更新时间：2020-08-12
- 摘要：A two-peak adjustable semiconductor luminescent material BaZn2(BO3)2:xEu3+ phosphor was prepared by high temperature solid state method. The phosphor has a strong absorption in the ultraviolet band in the range of 300 to 400 nm. With the excitation of 375 nm, this phosphor exhibits two broad emission bands, peaked at 550 and 615 nm. And under the excitation of 393 nm, this phosphor exhibits a strong broad emission band, peaked at 615 nm due to the 5D0→7F2 electric dipole transition of Eu3+, which indicates that Eu3+ occupies an anti-inversion symmetry, and partly replaces the divalent Ba2+ in the BaZn2(BO3)2 lattice. When the mole fraction of Eu3+ reaches 10%, the concentration quenching occurs. The color hue of BaZn2(BO3)2:xEu3+ phosphors under different doped concentrations of Eu3+ ions can be tuned from yellow to red.关键词：phosphors;BaZn2(BO3)2:Eu3+;white LEDs141|126|0更新时间：2020-08-12
- 摘要：In order to improve the water solubility of naphthalimide and the combination with the paper, the polystyrene fluorescent emulsion was prepared by emulsion polymerization, and its synthesis conditions were optimized. The structure was determined by FT-IR and gel permeation chromatography(GPC). The optical properties were measured by UV and fluorescence spectra. Its morphology was observed by scanning electron microscopy and transmission electron microscopy. The fluorescence quantum yield is 78.57%. After polymer coats on the surface of the paper, its initial whiteness increases by 8.19%(ISO). After 48 h UV light irradiation, compared with that of the blank paper and the paper which coats the micromolecule fluorescent whitening agent, the whiteness of the paper which coats the polymer decreases by 3.68%(ISO) and 3.16%(ISO), respectively. The results show that the prepared polymer emulsion and paper adhesion are good, with whitening and yellowing inhibition.关键词：yellowing inhibitor;naphthalimide;styrene;stability of polymer emulsion115|234|2更新时间：2020-08-12
- 摘要：KTm0.1Yb0.9(WO4)2 laser crystal was grown by the Kyropoulos method. The phase and structure of the crystal were studied using the X-ray single crystal diffraction and X-ray powder diffraction. Combined with the X-ray single crystal diffraction method, the structure model of the crystal was obtained by the diamond crystal graphics software. It is indicated that the crystal consists of WO6, TmO8/YbO8 and KO12 groups. The W2O10 dimers, which are connected by the single oxygen bridge(WOW), have a formation of the(W2O8)n multiple bands in the direction of parallel to the c axis. TmO8/YbO8 and KO12 are connected with the same vertex, which can form an extension band along the[101] and[110] directions with a two-dimensional structure. X-ray powder diffraction analysis indicates that the crystal belongs to monoclinic system with a space group C2/c. It is verified that as-grown crystal is β-double tungstate with low temperature. The cell parameters, crystal grain size and crystallinity of the crystal were calculated as well. The vibration spectra of the crystal were investigated. The vibration modes and frequencies of infrared and Raman peaks were identified, which could further verify the presence of WO6 groups, single oxygen bridges(WOW) and double oxygen bridges(WOOW) in the crystal.关键词：KTm0.1Yb0.9(WO4)2 laser crystal;structure simulation;vibration spectra124|110|0更新时间：2020-08-12
- 摘要：In order to achieve high-sensitivity surface-enhanced Raman scattering(SERS) at a low cost, a kind of SERS substrate based on the nanostructures of silicon was fabricated. The monocrystalline silicon was treated with low-energy reactive ion implantation. Highly steep nanostructures were fabricated on the surface of the monocrystalline silicon. Then the treated silicon was decorated with silver employing the way of electron beam evaporation. Ag nanoparticles and ‘hot spots’ formed on the side walls of nanostructures. The substrates with 40 nm-thickness silver obtain the most powerful Raman signal and reach a limit of 10-14 mol/L by employing the R6G as the probe molecule. We also analyze the stability and repeatability of the substrates. The characteristic peaks located at 614 cm-1 and 1 650 cm-1 own relative standard deviation of 12.3% and 14.3%, respectively. The substrates can obtain the characteristic signal of R6G as well after a month. This method is simple and cost-effective and the demonstrated SERS substrates offer the advantages of high-sensitivity, high-repeatability and high-stability.关键词：surface-enhanced Raman scattering;reactive ion implantation;Ag nanoparticles;electron beam evaporation;low cost124|409|0更新时间：2020-08-12
- 摘要：Er,Yb:(LaLu)2O3 ceramic powders were prepared via citric combustion method. XRD patterns show that the production prepared at 1 000℃ is pure phase of (LaLu)2O3. Er,Yb:(LaLu)2O3 and Er:(LaLu)2O3 ceramic was synthesized by cold isostatic-vacuum sintering method. The structural and spectroscopic properties of the ceramics were investigated in detail. The upconversion emission increases obviously when 5% Yb3+ and 10% La3+ are doped in the ceramic compared with the samples without Yb3+ and La3+ doping. The upconversion fluorescence spectra show that the intense green and red emissions located at around 564 nm and 661 nm are attributed to the radiant transitions of 4S3/2(2H11/2)→4I15/2 and 4F9/2→4I15/2 of Er3+, respectively. The energy transfer process and upconversion luminescence mechanism of Er3+-Yb3+ in co-doped system were studied.关键词：erbium and ytterbium co-doped lanthanum lutetium oxide;citric combustion method;cold isostatic-vacuum sintering;spectroscopic properties131|187|2更新时间：2020-08-12
- 摘要：Rubrene receives extensive attention by researchers due to its excellent fluorescence and semiconductor properties of good electrical conductivity and high absorption coefficient, it has the highest mobility of single-crystalline, and will have a great development prospect in organic optoelectronic devices. At present, vacuum evaporation and solution-processing methods are mainly used to fabricate crystalline rubrene thin film by domestic and international scholars, various preparation processes are used to improve the quality of rubrene thin films. In this article, the influence of doping type, polymer concentration, post-treatment process and experimental temperature on the properties of rubrene crystal are summarized based on the systematic introduction about research progress in the fabrication process of rubrene thin films. The research achievements of rubrene thin films in the application of organic optoelectronic devices are summarized briefly. At last, the development trend of the optoelectronic devices based on the crystalline rubrene thin film is prospected.关键词：Rubrene;organic optoelectronic device;solution process;vacuum evaporation;polymer113|433|0更新时间：2020-08-12
- 摘要：The electron structures and micromechanism of light emission on wurtzite (In,Al)GaN alloys with four configurations (uniform, short chain, small cluster and a combination of clusters and chains) were investigated based on first-principles density functional theory. The results show that the electrons of both short In-N-chain and small In-N clusters in InGaN alloy are localized at the valence band maximum (VBM) states. When the small cluster and the short chain coexist in the InGaN alloy, the former is much stronger than the latter in terms of the ability of electrons localization, and the small cluster is the radiative recombination luminescence center. However, in AlGaN alloy, the effect of the short Al-N-chain and the small Al-N clusters on the valence electrons localization at the VBM states is not remarkable. Microstructure difference of alloy can cause the change of the electronic localization, which affects the luminescence performance of the material, and the difference also has significant influence on the band gap and the bowing parameter.关键词：first principle;(In;Al) GaN alloys;In cluster120|167|0更新时间：2020-08-12
- 摘要：The phosphor Ba3Y4-xO9:xDy3+ was synthesized by traditional high-temperature solid-state reaction method. The structure and luminescence properties were characterized using X-ray powder diffraction, photoluminescence spectra (PL) and fluorescence decay time. The results indicate that the excitation spectrum includes a series of linear peaks, located at 328, 355, 368, 386, 427, 456, 471 nm. The main emission peaks were located at 490 nm(4F9/2→6H15/2)and 580 nm(4F9/2→6H13/2) under 355 nm excitation. The chromaticity coordinates of Ba3Y4O9:Dy3+ phosphors were measured, which were in the yellow region. The effect of the doping concentration of Dy3+ was investigated, and found the samples of luminescence intensity increased with the increasing of the concentration of Dy3+, but the spectral shape basic remains the same. This indicates that Dy3+ occupies the Y3+ position of low symmetry in the matrix. The concentration quenching occurred when x=0.08 for Ba3Y4-xO9:xDy3+ phosphor and its mechanism is ascribed to dipole-dipole interaction. The decay time of the phosphor decreases with the increase of Dy3+-doped concentrations, this is further evidence that there exists a phenomenon of energy transfer between the Dy3+ ions. Ba3Y4O9:Dy3+ phosphors are located in the yellow region and have good thermal stability.关键词：Ba3Y4O9;yellow light;fluorescent material;optical properties161|439|4更新时间：2020-08-12
- 摘要：In order to improve the thermal performance of LED lamp with high heat flux in natural convection, a thermoelectric cooler (TEC) was presented to meet the cooling requirement of a compact lamp with single high-power LED. The performance parameters of TEC were determined accurately by regression analysis for TEC experimental data at different work status. The equivalent thermal circuits of the compact LED modules with TEC and without TEC were established based on electrical-thermal analogy. Some mathematic models of equivalent thermal circuits were developed to quickly predict the accurate thermal performance of LED modules following the specified calculation procedure in this paper. The thermal performance analysis results show that the best cooling performance can be obtained at the optimum input TEC current for a specific LED power dissipation. The thermal performance of LED modules with TEC can be superior to that of modules without TEC and be better at low LED power dissipations than at high ones. Two-objective optimization was carried out using three design variables of fin to minimize the junction temperature and fin mass simultaneously. For the un-optimized and optimized modules, the comparison results of thermal performance demonstrate that the effective operating range of TEC in optimized module performs broader than that in un-optimized module. The LED power dissipation of optimized module can reach a higher performance than that of un-optimized one. At the LED power dissipation of 0.493 W, the minimum junction temperature is 15.66℃ and much lower than the ambient temperature of 30℃. For the LED modules with TEC, the equivalent thermal circuit models presented based on TEC experimental data can contribute to the thermal design, performance analysis and structural optimization.关键词：LED cooling;thermoelectric cooler;natural convection;thermal circuit method;optimization138|289|1更新时间：2020-08-12
- 摘要：AlGaInAs MQWs 1 300 nm FP lasers were packaged p-side down with a reflective submount which had 10-20 μm Au film near the facets of laser bare die. Compared to convention package form laser (LD-B), the divergence angle at FWHM of flip chip (LD-A) with a Au reflector decreases from 34.5° to 17°, and the average SMF coupling power increases from 1 850 μW to 2 326 μW, as the coupling efficiency increases from 21.1% to 26.5%. Compared to LD-B, the saturated current of LD-A increases from 135 mA to 155 mA, the saturated output power increasses from 37 mW to 42 mW, and the thermal resistance decreases from 194 K/W to 131 K/W. Finnaly, the aging experiments are carried out under the condition of 95℃ ambient temperature and 100 mA injection current. Compared to LD-B, the degradation coefficient of LD-A under aging condition decreases from 4.22×10-5 to 1.06×10-5, and the lifetime increases from 5 283 h to 21 027 h.关键词：AlGaInAs MQWs laser;flip chip;Au reflector;divergence angle;accelerated aging120|257|0更新时间：2020-08-12
- 摘要：One dimension photonic crystal coupled microcavity structure with anisotropic left handed materials is investigated by means of the transfer matrix method. It is shown that two kinds of minibands are formed in the structure. One is conventional Bragg miniband, the other is zero mean refractive index miniband. When modulating the thickness of the cavity, two type minibands turn into two type of Wannier-Stark ladder. The transmission and period of oscillation are found to decrease with the increasing gradient factor.关键词：anisotropic;left handed materials;photonic crystal135|130|0更新时间：2020-08-12
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Optical Property of The Atmospheric Pressure Argon Plasma Jet Generated by Three Types of Electrodes
摘要：The atmospheric argon plasma jet generated by three kinds of electrode configurations was obtained, and the discharge characteristics of the plasma jet were investigated by electrical and optical methods. First, the discharge current and quantity of electric charge were measured by electrical method simultaneously. Meanwhile, the discharge pulse and average discharge power were investigated. The plasma parameters of the plasma jet were studied by spatial resolved optical emission spectroscopy. In addition, the excited electron temperature was estimated by spectral intensity of ArⅠ 763.5 nm and ArⅠ 772.4 nm. It is found that the discharge current pulses are asymmetric at different discharge phases. With the increase of the applied voltage, the discharge powers of the three electrodes are increased from 1.7 W to 6.0 W. At the same applied voltage, the smaller the area of the electrode is, the longer the length of the plasma jet becomes. Besides the above results, we also found that the excited electron temperature decreases from 3 212.1 K to 1 348.5 K with the increase of the gas flow rate, while the electron density of the plasma jet decreases with the gas flow rate. The experimental results show that the applied voltage has some influence on the discharge power and the length of jet is related to the electrode area. The gas flow rate plays an important role in the excited electron temperature and the spatial distribution of electron density.关键词：plasma jet;electrode configuration;discharge power;excited electron temperature;electron density176|289|3更新时间：2020-08-12 - 摘要：In order to use different band LED for fast and accurate simulation of the solar spectrum,based on the LED spectral synthesis principle, a way to synthesize the solar spectrum by using the data at their peak wavelength of LED spectrum was put forward, the fitting process of solar spectrum was simplified. First, the function equations for all LEDs at their peak wavelength were established, the constraint least-squares method was used to determine the fitting parameters of each band. And then, the method was simulated by three sets of equal spaced LED spectral data sets, the correlation coefficients of the LED synthesis spectra with the target spectra at the interval of 40, 30, 20 nm were 0.902, 0.935, 0.977. Finally, The solar spectrum was simulated according to the actual spectrum of the selected LED. The simulation results show that the maximum mismatch error between the synthesized spectrum and the solar spectrum is 4%, achieving the standard of AM1.5 A level and meeting the LED solar simulator spectral matching requirements.关键词：LED solar spectrum;spectral synthesis;peak wavelength;solution of constrained least-squares119|328|2更新时间：2020-08-12
- 摘要：MB2BA/ZnO nanocomposites with different mass fraction of liquid crystal N-(4-methoxybenzylidene)-4-ethoxybenzenamine(MB2BA) were successfully prepared by ultrasonic dispersing technology. The prepared MB2BA/ZnO nanocomposites were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and photoluminescence(PL) spectroscopy, respectively. The experimental results show that the UV emission of ZnO nanocrystals and PL of the MB2BA is about to form a blue emission band with its peak located at about 418 nm when the concentration of MB2BA in ZnO is up to 80%. By increasing the concentration of MB2BA in ZnO nanocrystals, deep-level luminescence obviously weakened with reducing the surface defects of the ZnO nanocrystals, and the originally yellow-green photoluminescence of the ZnO nanocrystals can be tuned to blue. Our results demonstrate that the blue colored photoluminescence can be achieved by mixing appropriate amount of MB2BA with ZnO nanocrystals.关键词：ZnO;ultrasonic dispersing technology;photoluminescence118|192|0更新时间：2020-08-12
- 摘要：The three-dimensional fluorescence spectra of the samples were measured by FS920 fluorescence spectrometer, and the characteristic information of three-dimensional spectral grayscale was extracted directly by Tchebichef moments. And then, the cluster analysis was carried out. Finally, a linear model of each component in the sample was established by the stepwise regression. Clustering analysis can identify doping sesame oil with a high recognition rate and can correctly analyze its constituent components. R-squared of the obtained linear model is greater than 0.99. The results show that Tchebichef moments can effectively extract the characteristic information of the spectrum and can be used to identify the doping sesame oil and obtain good qualitative and quantitative analysis results.关键词：three-dimensional fluorescence spectroscopy;Tchebichef moments;clustering analysis;quantitative analysis;adulteration identification118|217|4更新时间：2020-08-12
- 摘要：A fluorescent enhancement probe(for short:NCFP) was designed and synthesized based on the naphthalene imide derivatives grafted chitosan through imidization, schiff base reaction, and so on by using 1,8-naphthalene anhydride, chitosan, moroxydine hydrochloride as raw materials. The structure of the fluorescent probe was characterized by 1H NMR, FI-IR method, the spectral properties and identification of metal ions were studied with fluorescence spectroscopy. The results indicate that the fluorescent probe has strong fluorescence responses to Al3+, and remarkably high selectivity to Al3+ than other metal ions. When the concentration of Al3+ is in the range of 29.90-253.41 μmol/L, there is a good linearity between the fluorescence intensity of the probe and the concentration of Al3+. Linear correlation coefficient R2=0.997 9, the detection limit of the probe is 4.279 μmol/L to Al3+. The complexation ratio of probe/Al3+ is 1:1 from the method of Job's plot by fluorescence pectrophotometry.关键词：naphthalimide;chitosan;fluorescent probe;identification performance130|112|1更新时间：2020-08-12
- 摘要：Due to the limitation of chemical testing methods, we cannot get reference value of agro-product qualities in every pixel location and are not directly to verify spatial prediction results of agro-product qualities based on spectral images. In order to research spatial prediction laws of agro-product qualities based on spectral images, the computer was used to generate the samples of known spatial distribution and to acquire the spectral images of different gray-level reflectance standard boards by ways of fixed and variable exposures respectively. The error of data acquisition system was analyzed quantitatively. The spatial prediction accuracy model of spectral imaging was built and the prediction accuracy law of spatial qualities was researched as regional parameter values which could be predicted accurately by means of partial least squares(PLS) prediction methods based on full wavelengths and characteristic wavelengths between regional spectral values and regional parameter values. The results show the signal-to-noise ratio of the spectral image can be improved by changing exposure time and it is more obvious on both sides of the spectral band. When these models that can predict regional parameter values accurately are used to predict space parameter values, their spatial prediction accuracy is affected by error in a similar way. The accuracy of spatial prediction results of agro-product qualities can be evaculated by the way of measuring the error of the data acuisition system. Spectral image detection technology can be used to predict spatial parameter values of agro-product qualities when the error of acquisition system is limited in a specified range.关键词：space prediction;spectral image;genetic algorithm;partial least squares;systematic error117|157|1更新时间：2020-08-12
- 摘要：The nanocomposites of Au nanoparticles/aptamers/quantum dots were constructed by self-assembly. Fluorescence of CdTe quantum dots can be quenched by Au nanoparticles in the nanocomposites. The fluorescence of the system can recover when aflatoxin B1 (AFB1) is added to the assay solution, specific interactions between AFB1 and the aptamer cause release of the quantum dots. A linear fluorescence signal response to AFB1 concentration is obtained over a wide AFB1 concentration range of 0.005-2.00 ng/mL with a detection limit of 1.2 pg/mL. The proposed method has been employed in the determination of trace AFB1 in forsythia suspense, hawthorn and radix liquiritiae successfully.关键词：aptasensor;quantum dots;determination;traditional chinese medicine;aflatoxin B1134|126|0更新时间：2020-08-12
- 摘要：In order to enhance the research on American solar PV market, this article collected the data of American solar resource distribution status, solar PV installations, system pricing, solar related policies, and also analyzed and forecasted the near future solar market development trend. Based on the study of the data mainly provided by America department of energy (DOE), Solar energy industries associations (SEIA), a general view of American PV solar market was provided. Through the talks with the American investment bankers, PV solar project developers, and the study of the solar policies, a general introduction of the investment tax credit (ITC), modified accelerated cost recovery system (MACRS), renewable portfolio standard (RPS) was given. Finally, Based on the research of SEIA, forecast on the American solar PV development trend was presented. Amercian solar PV market is highly driven by the government policies and subsidies, by the end of 2016, total solar PV installation reached 400 GW, ranked No.4 in the world, expecting a slow growth rate in 2018, then the growth rate will start to go up gradually between 2019 and 2022.关键词：American solar PV market;polices;forecast153|126|1更新时间：2020-08-12
- 摘要：A one-step hydrothermal method was developed for the preparation of carbon quantum dots(CQDs) with strong fluorescence by using red dates as precursors. The luminescence properties of the CQDs were studied by fluorescence spectroscopy, UV-Vis spectrum, transmission electron microscopy, infrared spectrum, X-ray powder diffraction spectroscopy. In pH=4.00 NaAc-HAc buffer solution, after potassium permanganate(KMnO4) was added in CQDs solution, the fluorescence of CQDs was quenched, and the fluorescence signal of the system was in the "off" state. In the presence of rutin, the fluorescence of CQDs was recovered because KMnO4 preferred to react with rutin, which results in the departure of KMnO4 from the surface of the CQDs, and the fluorescence signal of the system was "open". The degree of recovery of CQDs fluorescence intensity was proportional to the rutin concentration, which provided a new method for the detection of rutin with high sensitivity and selectivity based on the fluorescence quenching-recovery properties of CQDs. The mechanism of fluorescence quenching of CQDs by KMnO4 was studied, and the reaction conditions were optimized. Under optimal conditions, the recovered fluorescence of CQDs is linearly related with the rutin concentration in the range 2.5×10-7-1.0×10-5 mol/L, the detection limit is 1.5×10-7 mol/L. The present method is applied for the detection of rutin in samples with satisfactory results.关键词：carbon quantum dots;fluorescence probe;rutin;potassium permanganate;red dates152|124|10更新时间：2020-08-12
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