最新刊期
卷 40 ， 期 8 ， 2019
- 摘要：By a series of characterization of quantum dots and their films for different synthesis conditions and preparation parameters, the synthesis conditions of cesium lead bromide quantum dots and the quantum dots film preparation parameters are optimized. The effects of reaction temperature and reaction time on the properties of CsPbBr3 perovskite quantum dots were studied by thermal injection. The quantum dot samples of perovskite under different synthetic conditions were obtained and characterized. Then all CsPbBr3 quantum dot samples were prepared into thin films to explore its photoluminescence properties. When the reaction temperature is 180℃, the reaction time is 5 s, the quantum dot size is 9 nm, reaching the minimum value. With the spin speed of 3 000 r/min, the annealing temperature of 80℃ and the annealing time of 10 min, the CsPbBr3 quantum dots film has the strongest photoluminescence intensity. The optimum synthesis conditions of CsPbBr3 quantum dots and the CsPbBr3 quantum dots film preparation conditions were obtained.关键词：perovskite;CsPbBr3;quantum dot;TEM;photoluminesecence(PL)244|492|9更新时间：2020-08-12
- 摘要：ZnO is an excellent UV light-emitting and lasing materials. Nitrogen is considered to be the ideal acceptor dopant for p-type ZnO and MgZnO. However, the lattice integrity of the nitrogen-doped samples grown at the lower growth temperature is remarkably influenced, which results in a further decrease in the carrier mobility of the zinc oxide. In order to study the effect of N doped MgZnO films, N-doped ZnO and MgZnO thin films were grown on sapphire substrate by molecular beam epitaxy. Comparing the difference between N doped MgZnO and ZnO, the experimental results show that the carrier mobility increased significantly when the Mg source temperature was 245℃ and 255℃, which is attributed to the fact that Mg-N bonding alleviates the formation of N-N pairs on the oxygen sites and relieves the lattice distortion. At the same time, the donor concentration in N-doped ZnO thin films can be reduced by one order of magnitude when the Mg source temperature is 275℃, which is advantageous for p-type doping.关键词：molecular beam epitaxy(MBE);MgZnO thin films;photoelectric properties150|164|1更新时间：2020-08-12
- 摘要：BaGd2ZnO5:Sm3+ microcrystalline powders with different Sm3+ doping concentrations were prepared by conventional solid phase method. It was confirmed by X-ray diffraction pattern analysis that all the products were pure phase BaGd2ZnO5. The diffuse reflection spectrum of the microcrystalline powder was measured by an integrating sphere and the absorption spectrum was calculated. According to the absorption spectrum, the spectral intensity parameter Ωλ(λ=2, 4, 6) of the sample is calculated, and the theoretical oscillator strength and the experimental oscillator strength are calculated, and the deviation is δrms=1.26×10-7. The electric dipole moment transition probability, the magnetic dipole moment transition probability, the transition branch ratio and the energy level lifetime parameters of each energy level transition of Sm3+ are calculated. It is found that the 4G5/2 energy level has a long lifetime of 4.82 ms and can be used as the upper energy level of the laser generation process; the transition probability and transition branch ratio of 4G5/2 to 6H9/2 and 4G5/2 to 6H7/2 are significantly higher. For other transitions, they correspond to two strong emission peaks at 610 nm and 660 nm in the Sm3+ emission spectrum. The excitation spectrum at an emission wavelength of 610 nm was measured, and six excitation peaks due to the 4f-4f transition of Sm3+ were found. In addition, the emission spectrum at 410 nm excitation was measured, and strong emission peaks at 570, 610, 660 nm were found, respectively. By studying the luminescence intensity at three strong emission peaks and the doping concentration of Sm3+, the concentration quenching phenomenon of Sm3+ luminescence is found. According to the analysis of energy transfer theory, the concentration quenching mechanism in Sm3+ ions belongs to dipole-dipole interaction. The calculation of the CIE color coordinates shows that all the coordinates of the five samples are in the orange-red region.关键词：BaGd2ZnO5;Judd-Ofelt theory;absorption spectrum;CIE coordinate142|190|0更新时间：2020-08-12
- 摘要：Ethyl 2-(4-methoxyphenyl)-5-phenyl-2H-1,2,3-triazole-4-carboxylate(EMPC) is a newly synthesized compound and used to investigate its theoretical spectrum and structural properties by quantum chemistry methods. Then EMPC was designed and synthesized to a novel rhodamine B derivative REMPC. The interactions of REMPC with 15 kinds of metal ions were investigated by fluorescence spectra and UV absorption spectra. The presence of Hg2+ ions could induce a significantly fluorescent enhancement and an intensive absorption of REMPC with a rapid chemical reaction in N, N-dimethylformamide(DMF)-H2O (V:V=1:1, pH=7.4). Meanwhile the triazole appended colorless chemosensor turns to pink upon complex formation only with Hg2+ ions and enables naked-eye detection. The equimolar continuous change method and structural computation were employed to measure the composition formed the new complex as 1:2 molar ratio. The corresponding off-on fluorescence mechanisms which were ascribed to Hg2+ inducing the ring-opened rhodamine B moiety were proposed. The fluorescence imaging experiments of Hg2+ in HeLa cell demonstrated that the probe was successfully labeled and it could be used in biological systems.关键词：Ethyl 2-(4-methoxyphenyl)-5-phenyl-2H-1;2;3-triazole-4-carboxylate;spectral properties;rhodamine B;chromogenic mechanism;Hg2+ ion165|81|1更新时间：2020-08-12
- 摘要：In order to study the effects of point defects on electronic structure and optical properties of Al0.5Ga0.5N nanosheets, the classical point defects structures of Al, Ga, N vacancies and N substitute Al and N substitute Ga are established. The method of first-principles ultrasoft pseudopotential based on density functional theory and the GGA-PBE exchange interconnect function are used to calculate the energy band, density of states, complex dielectric function, complex refractive index, absorption spectrum and energy loss spectrum. The results show that the vacancy defects and the substitution defects will lead to the band gap getting narrow. The Al vacancy and the Ga vacancy all make the Fermi level enter the valence band, and the N vacancy makes the nanosheet exhibit n-type properties. The substitution defect will make the nanosheet exhibit semi-metallic properties. In terms of optical properties, the defects lead to produce peaks in the low energy region of the imaginary part of the complex dielectric function of the nanosheet, indicating the occurrence of electronic transitions. At the same time, the vacancy defect causes the absorption spectrum to expand in the low energy region, and the visible light range is also included.关键词：Al0.5Ga0.5N nanosheets;first-principles;electronic structure;optical properties172|70|0更新时间：2020-08-12
- 摘要：In order to realize the detection of singlet oxygen during photodynamic therapy, a singlet oxygen nanoprobe with good water solubility was designed. Firstly, the 1,3 diphenylisobenzofuran(DPBF) was encapsulated in the nanoparticles by reprecipitation. Then the nano-probes were characterized by transmission electron microscopy, dynamic light scattering particle size and absorption spectrum. The nanoparticle with good dispersibility is about 200 nm and has a characteristic absorption peak of DPBF at around 426 nm. Finally, indocyanine green(ICG) was selected as a photosensitizer, and the generation of singlet oxygen was detected by the change of the absorption peak of the nanoprobe. The results show that the nanoprobe has high sensitivity to singlet oxygen and is promising in the monitoring of singlet oxygen for photodynamic therapy.关键词：DPBF;singlet oxygen detection;nanoprobe;photodynamic therapy506|847|1更新时间：2020-08-12
- 摘要：In photodegradation studies, the effect of main experimental parameters on the decolorization efficiency was studied and optimized. The maximum decolorization efficiency of 95.3% was obtained when the initial MG concentration, M-CS/ZnS:Fe dosage, and contact time were optimally set as 10 mg/L, 100 mg/L, and 60 min, respectively. The process kinetics can be successfully fitted to the first order kinetics of Langmuir-Hinshelwood model. Moreover, M-CS/ZnS:Fe could be easily separated under an external magnetic field. After five consecutive runs, a small and gradual decrease from 95.3% to 80.8% in the decolorization ration was observed.关键词：magnetic chitosan;ZnS:Fe;quantum dots;malachite green;photodegradation117|94|0更新时间：2020-08-12
- 摘要：Metal photonic crystals (MPCs) consisting of periodic Ag-ITO multilayers were demonstrated in the paper. The optical transmittance and reflectance of MPCs with different cycle size and number were simulated by finite difference time domain (FDTD) method. It is found that the optical transmittance of the MPCs broadens and the intensity accordingly decreases as the cycle size increasing. For one hand, As the numbers of cycle increasing, the numbers of transmitting resonant peaks correspondingly increase, and the bandwidth of transmittance obviously broadens until the number of cycle reaching to 4. For the other hand, the location of center wavelength evidently blue shifts as the incident angle increasing. At same time, the bandwith of transmittance broadens and the intensity of that distinctly decreases. Meanwhile, the numbers of transmittance peak obviously grow up as the layers of metal films increasing. It is also demonstrated that the location of transmittance peaks and reflectance valley is one to one relationship.关键词：metal photonic crystal;visible light transmittance;visible light reflectance;incident angle115|456|2更新时间：2020-08-12
Synthesis and Properties of Materials
- 摘要：The LD side-pumped Nd:YVO4 high repetition rate 355 nm ultraviolet laser is developed. According to the advantages of high gain and wide pump bandwidth, LD side-pumped structure is designed in the pumping mode of the laser. Using the acousto-optic Q-switched method and selecting the LBO nonlinear crystal with typeⅠand type Ⅱof phase matching, the V-resonance-cavity stucture of the intra-cavity triple frequency is designed. The output of 355 nm ultraviolet laser with high repetition rate and high gain is obtained. A maximum average output power at 355 nm of 8.5 W is obtained when the repetition rate is 20 kHz and the pump current is 30 A. Meanwhlie, the corresponding pulse width is 37 ns at 355 nm, the optical-optical conversion efficiency is 25.8% and the pumping threshold of the UV laser is about 16 A.关键词：LD side-pumped Nd:YVO4;ultraviolet laser;high repetition rate201|137|1更新时间：2020-08-12
- 摘要：The space cryogenic absolute radiometer (SCAR) is developed at Changchun institute of optics, fine mechanics and physics, in order to satisfy the demands of accuracy and traceability of onboard radiance calibration of spaceborn remote sensors. In this paper, the design decision of SCAR was introduced with emphasis, based on the brief introduction of the state-of-the-art of the cryogenic radiometer benchmark. The working environment of 20 K of SCAR was supplied by a stirling-type cryocooler. The responsivities of total cavity and spectral cavity were designed to be 0.2 K/mW and 1 K/mW by optimizing the structures of cavities and thermal links. The radiance benchmark can be founded by the optical power measurement of 0.02% accurate, which was ensured by close-loop high precision temperature control and electrical substitution measurement procedure with twice electrical heating, as always as the excellent thermal properties of detectors at low temperatures. The radiance standard was transferred to the spectral cavity through temperature comparing, in order to realize the traceable spectral radiometric measurement. This work affords technical reserve for the traceable spectral radiance calibration of spaceborn remote sensors.关键词：radiance benchmark;radiance calibration;traceability;cryogenic radiometer204|377|5更新时间：2020-08-12
- 摘要：Focused on the fluid motion mechanism and corresponding electro-optic response characteristics in the electrowetting display, a numerical simulation calculation method is proposed to calculate the interface change between the conductive fluid and the non-conductive fluid in electrowetting and the motion of the fluid-liquid-solid three-phase contact line under the influence of an externally applied electric field. The method is based on Matlab numerical analysis framework. The Young-Laplace equation is used to calculate the change of interface shape and the parameters such as three-phase contact angle and interface contact area during the change process. The electro-optical response process of the pixel is solved by overall energy balance equation. The experimental results show that, the model successfully simulates the electrohydrodynamic characteristics of the electrowetting display, and the pixel response time is proportional to the oil-water interfacial tension. The simulation results of the electro-optical response have good qualitative consistency with the experimental data of the same reference geometry, which can be used to guide the design of the fluid parameters in the electrowetting device, and it is important for realizing the display of highly stable electrowetting display.关键词：electrowetting;optical response;aperture ratio;overall energy balance;Young-Laplace143|328|2更新时间：2020-08-12
Device Fabrication and Physics
- 摘要：Aiming at the phenomenon of large amount of soil hyperspectral data, spectral information redundancy and overlap, a model for estimating soil organic matter content is established by using a stable competitive adaptive reweighting sampling strategy and combining partial least squares regression with random forest. The results are compared with those obtained by competitive adaptive reweighting algorithm, iterative iteratively retains information variables, successive projections algorithm and genetic algorithm. The five variable selection algorithms selecting the characteristic variables mainly distribute in the near infrared spectral region of 1 900-2 400 nm. The prediction effect of the RF model is better than that of the PLSR model. Compared with the PLSR model, the RF model has better robustness, lower sensitivity to outliers and noise. The RF model is established based on the characteristic variables selected by sCARS algorithm. The number of variables is 51, accounting for only 2.55% of the whole band. The verification set R2 is 0.958, and the RPD is 4.7, which can predict the SOM content very well.关键词：soil organic matter;Vis-near infrared spectra;stabilization competition adaptive reweighted sampling;random forest;Huangshui River Basin173|204|16更新时间：2020-08-12
- 摘要：Drop volume is important for quantitative printing, while ink viscosity has an important influence on droplet volume. First, a nozzle model was proposed based on laminar flow-level set method. The ejection processes of droplet with different viscosity at different moments were demonstrated, under the condition that the ink density is 1.0 g/mL, the surface tension is 28 mN/m, and the viscosity is 1-15 mPa·s, and the negative correlation between the droplet volume and viscosity of ink was obtained. Then, the droplet volume was quantified through the integration of the level-set function, and the variation range is 58.10-37.29 pL; and a negative linear relationship between the volume of droplet and the ink viscosity was obtained by linear fitting, specifically, "A=-1.54","B=60.2". Secondly, the printing experiment was carried out by the printing of polythiol ink under the same physical parameters, and the variation range of droplet volume was 149.9-92.9 pL, and the specific fitting relationship between the droplet volume and the ink viscosity was still a negative linear relationship:"A'=-4.12","B'=154.71", which proved the simulation result. And the results of simulation and experiment show that there is a coefficient "h=2.5" between the linear function of them, and coefficient "h" was proven to be independent of the type of ink, but to be determined by the inlet pressure through the further simulation research. This study can help to simplify the quantitative printing process of any type of ink with a lower viscosity.关键词：inkjet printing;viscosity;droplet volume;simulation207|493|4更新时间：2020-08-12
- 摘要：In order to deeply understand the mechanism of Ar plasma jet under atmospheric pressure and the state of internal electron, the emission spectrum diagnosis of Ar plasma jet was carried out. The electron excitation temperature was calculated by Boltzmann slope method, and the electron density was calculated by the continuous spectral absolute intensity method of emission spectrum. The effect of argon pressure and discharge power on electron excitation temperature and electron density of Ar plasma jet was studied by designing a metal needle-ring dielectric barrier discharge device with adjustable air pressure. The results show that with increased pressure from 6 kPa to 16 kPa, electron excitation temperature reduced from 0.83 eV to 0.68 eV, electron density from 4.45×1022m-3 to 0.44×1022 m-3, and with increased discharge power from 0.177 5 W to 1.792 6 W, electron excitation temperature increased from 0.82 eV to 5.14 eV, electron density increased from 0.27×1022 m-3 to 4.61×1022 m-3, and when the electron density is lower, electron excitation temperature change is more obvious. It is concluded that argon pressure and discharge power not only have direct effects on the electron excitation temperature, but also have indirect effects caused by the change of electron density. When the electron density is low, the influence of argon pressure and discharge power on the electron excitation temperature will be relatively greater. At the same time, the results of electron density calculated by using two wavelengths are very close, which verifies the accuracy of the diagnosis results.关键词：plasma jet;emission spectrum;absolute intensity;electron excitation temperature;electron density181|123|4更新时间：2020-08-12
- 摘要：The Vis/NIR hyperspectral imaging technique combined with chemometrics method was applied to build a glucose contect prediction model, which provided a scientific method for the rapid non-destructive detection of glucose content in Lingwu long jujube. The spectral data were acquired by Vis/NIR hyperspectral imaging(400-1 000 nm). Simultaneously, high-performance liquid chromatography was used to detect the glucose content; after eliminating abnormal sample data and dividing into sample set, the 6 pretreatment methods were used to process original spectrum. Then the characteristic wavelength was selected from the pretreatmented spectral data by 7 methods, and the PLSR and MLR prediction models were established based on full wavelength and feature wavelength, respectively. The results show that the SG(7)method is the optimal pretreatment method; and the number of the characteristic wavelengths by CARS, IRF, SPA, BiPLS, UVE, IRF+CARS and BiPLS+CARS are 18, 61, 7, 51, 15, 33, 27, respectively; the IRF+CARS model was the best among the models developed, and its Rc=0.835 3, Rp=0.832 2. So it is feasible to predicte glouse content of Lingwu long jujube based on hyperspectral imaging technique.关键词：visible-near infrared;hyperspectral imaging;Lingwu chang jujube;glucose;IRF203|235|8更新时间：2020-08-12
- 摘要：According to the analytical form of Voigt line shape function, the empirical formula of Voigt line shape width and Lorentz line shape width and Gaussian line shape width is established by numerical calculation method. Based on the empirical formula of line shape width, the calculation scheme of Lorentz and Gaussian width obtained by experimentally spectral line shape width is established. The reliability of our calculation scheme is verified by a set of line shape functions. According to the method established in this work, the 696.5 nm line of the Ar gas plasma jet is calculated, and the corresponding Lorentz line shape and Gaussian line shape function are obtained.关键词：Lorentz line shape function;Gaussian line shape function;Voigt line shape function;full width at half maximum intensity348|1481|1更新时间：2020-08-12
Luminescence Applications and Interdisciplinary Fields
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