最新刊期
卷 15 ， 期 1 ， 1994
- 摘要：Fine structural properties of ZnSe1-xSx-Znse strained-layer superlattices grown onGaAs (100) substrates by MOCVD were investigated by high resolution transmission electron microscope. Examination of the type and distribution of the defects has revealed that the appearance of defects has relation with the quality of buffer layer. The superlat-tices material that have smooth structure has been prepared by improving the composition of the buffer layer and the thickness of each layer of the superlattice.The superlattice quality was intensely dependent on the substrate surface and buffer layer surface. The superlattice grown on smooth buffer layer has smooth surface, and grown on poor buffer layer has poor quality,and has more defects.The critical layer thickness of ZnS epitaxy grown on smooth GaAs substrate is 2nm,it is slightly bigger than that theortically.The crystalline defects are found to be concentrated in the ZnS layers. It is found that mainly, the ZnS lattice constants change to match with the ZnSe lattice.The imperfection of superlattice structure also shows that there exists a great number of interface steps that make sublattices suspended.In atmospheric pressure growth the interface of ZnSe and ZnS layer exists some deep mutual diffused layer that makes the interface lattice image vague and, indistinct.关键词：superlattices;HRTEM;defect130|68|0更新时间：2020-08-11
- 摘要：In this paper,three organic thin film electroluminescence (OTFEL) cells with different thickness of luminescent layer:300Å,600Å,1500Å,were prepared. The OTFEL cells were the structure of single layer,and the 8-hydroxyquinoline aluminum was used as a luminescent layer. Comparing and analysising their properties of I-V and B-I, it is conformed that the thickness of luminescent layer drastically influences the brightness of OTFEL cells. The cause were discussed by transport processes of electrons and holes in luminescent layer under DC current.关键词：organic thin film;thickness;brightness141|57|5更新时间：2020-08-11
- 摘要：From the results of X-ray diffraction,it is certain that RVNb2O9(R=Y,Gd,La) can be obtained by solid state reaction with R2O3,V2O5 and Nb2O5.The luminescence properties of Eu3+ and Dy3+ in RVNb2O9 (R=Y,Gd, La) have been systematically investigated. It is shown that host can sensitize Eu3+ and Dy3+ in these compounds. Eu3+ occupies site with deviation from inverse center in RVNb2O9 (R=Y,Gd,La), because the intensity of 5D0-7F2 transition of Eu3+ is stronger than that of 5D0-7F1 transition and the transition of 5D0-7F0 does not appear in these three matrixes(Fig. 1),The red-to-orange intensity ratio (R/O) of Eu3+ and the yellow-to-blue intensity ratio (Y/B) of Dy3+ decrease with decreasing of the charge-to-radius ratio (Z/r) of R3+ (Table 1).The influence of Bi3+ and temperature on the emission intensity of Dy3+ were also investigated, Bi3+ acts as a "killer" for the emission of Dy3+.关键词：europium;dysposium;bismuth;luminescence;spectroscopy99|45|2更新时间：2020-08-11
- 摘要：CaS,Se:Eu red DCEL panels are prepared. Mix a small amount of Se to CaS:Eu can improve DCEL properties. The effect of Pb on CaS:Eu is studied,through measurement of emission, excitation spectra and decay time,it is suggested that Eu2+ is sensitized by Pb2+. Compared with the conventional CaS:Eu, the DCEL efficiency and lifetime of CaS:Eu, Pb has been obviously increased.关键词：direct current electroluminescence (DCEL);sensitization;calcium sulfide (CaS)100|50|0更新时间：2020-08-11
- 摘要：A series of LaP3O9:Ce,Gd,Tb phosphors have been prepared by a solution-precipitation method. X-ray structural analysis showed that they are fairly pure LaP3O9 phase, with a cyclic-(PO3)3-structure, belonging to orthorhombic syngong;with cell parameters a=11.19,b=8.54,c=7.28Å, Their excitation and emission spectra,relative brightness and the luminescence lifetime of Ce3+ have been measured. It was observed that the spectra of Ce3+ overlaps with that of Gd,showing that there is some interaction in energy between these two ion;and Ce3+ can effectively sensitize Tb3+, so as to enhance the emission of Tb3+ significantly. LaP3O9:Ce,Tb might be a new high efficient green emitting phosphor. Adding a small amount of Gd to Ce,Tb codoped LaP3O9 led to the lowering of the emission brightness to a certain extent. This might be due to the competition absoption by Gd3+. From the luminescence lifetime of Ce3+ it can be inferred that the energy transfer from Ce3+ to Gd3+ is weak,whereas that from Ce3+ to Tb3+ is very efficient.108|61|4更新时间：2020-08-11
- 摘要：Under UV radiation, the body colour of ZnS type photoluminescent phosphor changes from gray to dark,at the same time the brightness of phosphor decreases (pho-toageing). As well known, light deterioration mechanism has been clarified, that is, under UV radiation, zinc atom which comes from the dissociation of ZnS,results in the brightness decay and the change of material colour. In this paper,the above conclusion has been identified by X-ray diffraction patterns measurement and analysis of ZnS phosphors. It is also found, that non-zinc element impurity phase is presented in X-ray diffraction patterm. The effects of different wavelength UV radiation on light deterioration of phosphors are studied in this paper. It is shown that the photoageing of phosphors is caused by 185nm UV. The effect of particle size on photoageing is also examined, it is concluded, that the smaller the particle size, the more serious the photoageing.关键词：ZnS type phosphor;UV radiation;photoageing (light deterioration)105|70|1更新时间：2020-08-11
- 摘要：The photoacoustic spectroscopy(PAS) has been widely used to study the non-radiation transition process for fluorescent materials in solid state especially. The PAS in LaOX:Ce3+ and MFX:Ce3+ (X=Cl-,Br-;M=Ba2+,Sr2+) are first reported in this paper. By comparing with fluorescent spectra of these samples,the quenching effects of O2 on Ce3+ in MFX and MF2(M=Ba2+,Sr2+) matrixes are discussed. It has shown that with the longer sintering time,the luminescent intensity decreases,whereas the signal of PAS is getting stronger and stronger accordingly. PAS expriments have also shown that the remaining trace oxygen (O2) quenched the emission of Ce3+ ion doped in MFX matrixes mainly through increasing the non-radiation transition probability of Ce3+,and because of the doping of non-fluorine halogen,MFX:Ce3+ systems posses higher resistance to quench than pure fluoride systems MF2:Ce3+. Additional,the luminescent center of Ce3+ in MFX matrixes is mainly center I (near 420nm)on this condition of non-oxygen syntheses.92|42|0更新时间：2020-08-11
- 摘要：It was observed in our MOCVD system that the aluminum distribution in the AlxGa1-xAs epitaxy layers varied with the Ⅴ/Ⅲ ratio used in the growth process. When the Ⅴ/Ⅲ ratio was lower, the Al distribution in the grown epitaxy layers was ununi-form and it became three layer’s structures with different Al contents in different layers; one layer which was near the buffer layer had lower Al content, the layer near the surface of the epitaxy layer had higher Al content and the third one located in the middle of the epitaxy layer was the layer with the middle value of the Al content. Increasing the Ⅴ/Ⅲ ratio, the aluminum distribution tended to uniform and the crystal of the epitaxy was more perfect. This phenomenon was attributed to decomposition,diffution and des-orption of Ga and As ions in the epitaxy layers.关键词：MOCVD;AlGaAs epitaxy;Ⅴ/Ⅲ ratio;Al distribution114|56|1更新时间：2020-08-11
- 摘要：In the present paper, the LB films of dansyl chloride (DNS) and 8-anilino-l-naph-thalene sulfonic acid CANS) derivatized octadecyl-amine(AM) were deposited on solid substrates and their photophysical behavior was studied by the steady-state and time-resolved fluorescence measurements.The surface pressure/molecular area curves for DNS-AM and ANS-AM in presence or absence of atearic acid (SA) show that solid-condensed films have formed. The collapse pressure for DNS-AM and (DNS-AM)/SA(1:9) is 30 and 58mN/m respectively; while that for ANS-AM and (ANS-AM)/SA(1:5) is 35 and 58 mN/m respectively. The A isotherms for DNS-AM and (DNS-AM)/SA are unusual with a platean. The isothermn of ANS-AM and (ANS-AM)/SA have a classical shape.No significant difference was found between solution spectra in the absence or presence of stearic acid for either DNS or ANS labeled octadecylamine. It means that the diluent stearic acid has no substantial perturbation to the spectral properties of the fluorescent derivatives. The emission bands of films have a small blue shift (25 and 13 nm for DNS and ANS systems respectively) with respect to corresponding solution bands. This blue shift likely implies that the fluorescent octadecylamine experiences more hy-drophobic microenvironment in ordered LB films than in the random state in solution.The fluorescence lifetimes for DNS-AM and (DNS-AM)/SA in deposited films and in spreading solutions are identical within the experimental error range, being 13.5±1.Ons. ANS-AM and (ANS-AM)/SA also have similar lifetime values in film and in solution (ca. 8 ns). This implies that the molecules deposited on the substrate did not change their microstructure(conformation,aggregation state and etc.). A small tendency of lengthening of fluorescence lifetimes of molecules in film as compared to that in solution,is consistent with the small blue shift of emission bands,indicating the more hydrophobic microenvironment of film molecules.The results show that the derivatization with fluorescent probes may render the long-chain amine,not possessing chromophores suitable for conventional spectral study, to be detected with sensitive fluorometry in deposited LB films.关键词：LB film of fluorescent probe labeled octadecylamine;fluorescence lifetime124|59|0更新时间：2020-08-11
- 摘要：The effect of varying conditions to Testosterone-3-carboxymethyl oxime-4-(10-methy)-acridinium-9-carboxylate (To-3-AEPMAC) on the light yield and binding affinity of Testosterone chemiluminescent-marker conjugate was investigated. For this purpose To-3-AEPMAC has been synthesized, the resulting was then evaluted as potential labels for the development of an immunoassay based on monitoring chemiluminescence. The conjugate was able to compete with testosterone for the binding siles of an antibody raised against To-3-CMO bovine serum albumin, and they showed high affinity as same as unaltered testosterone. The conjugate produced light up on oxidation by a hydrogen peroxide in basic condition and was not significantly affected the quantum yield. The chemiluminescent reaction was optimized in terms of pH 6.0 concentration of oxidant, sodium hydrate and conjugate design. Under optimal conditions, the conjugate was detectable at femtomolar levels. The lowest detection limit was obtained using To-3-AEP-MAC (0.18fmol). These results indicated that conjugate does not modify its chemiluminescent property and immunoreativity,the immunoassay techniques based on chemiluminescence can be developed with the label.关键词：acridinium ester;testosterone;synthesis;chemiluminescence;immuno-chemistry119|62|2更新时间：2020-08-11
- 摘要：The ploting and making method of color paint plate made of ACEL powder materials are reported in this paper. Some technical details for preparing process are discussed. The characters of this kind of color paint plate are they would express more stereo-like and life-like appearance.关键词：ACEL;application color;paint plate100|96|0更新时间：2020-08-11
- 摘要：Er ions were implanted in Ⅲ-Ⅴ compounds semiconductors GaP,GaAs and InP with relatively high dosages 5×1014/cm2 at 150keV and 350keV,respectively. Secondary Ion Mass Spectrpmetry(SIMS)depth profiles were carried out on a Cameca IMS4f ionmi-croprobe using a 600nA,15keV O2+ primary beam,rastered by 400m×400m over the sample. A mechanical aperture was employed to select positive secondary ions from the central portion of the crater(~60m in diameter). The crater total depth was measured using a profilometer. Depth profiles have been obtained and the peak depths in GaP, GaAs,InP are 55nm,51nm,56nm and 85nm,83nm,80nm at 150keV and 350keV,respectively. The sharp photoluminescence (PL)spectra have been observed at 1.538m, which correspond to the transition from the first state 4I13/2 to the ground state 4I15/2 of Er3+ after face to face annealing.101|71|2更新时间：2020-08-11
- 摘要：Two kinds of new luminescent materials, BLAO:Eu2+ and KLMAO:Eu2+, are obtained by diagonal line for periodic table and ions substituted laws. Blue emission about 450nm appears in the phosphors. Luminescent data in the new phosphors compare favourably with the phosphor BaMgAl10O17:Eu2+ and so they are probably applied to trichromatic fluorescent powder of rare earths after further study on these new phosphors.113|105|2更新时间：2020-08-11
- 摘要：A kind of polymer electroluminescence (EL) material poly(p-phenylene vinylene) (PPV) was synthesized and the EL devices were fabricated by spin-coatin. It was shown that this material had strong PL and good EL performance, and the spectra shapes changed with the thickness of the PPV thin films, also the EL spectra changed with the drive voltages, this is attributed to the reabsorption of the PPV film itself.Moreover, the PPV film was found can act as the hole transport layer (HTL) of the multi-layer TEFL devices. The EL devices using PPV as HTL and 8-hydroxyquino-line aluminum (Alq3) as emitting material were made, high brihtness more than 3700nt was measured, much better than that of those devices without PPV HTLs.152|92|4更新时间：2020-08-11
- 摘要：The present study examines the inhibitory efficiency on lipid peroxidation(LP) of ten-CH2CH2N(CH3 or C2H5)2-containing drugs. Data obtained from TBA-test and ultraweak chemiluminescence indicate that most of the drugs tested hold a strong anti-LP effect. Meanwhile,esperiments with a model system of xanthine and xanthine oxidase also show part of these drugs have efficient capacity of
-scavenging. The analysis of relations between drug-induced inhibition of LP and drug structure suggests that,apart from the above group,a polyatomic ring and an eletropositive center may also play an inportant role in lipid peroxidation inhibition. 115|40|2更新时间：2020-08-11
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