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A bilayer is used as a semitransparent cathode for top-emitting organic light emitting devices (top-emitting OLEDs). The bilayer cathode consists of samarium (Sm) and silver (Ag). Top-emitting OLEDs with the bilayer cathode showed enhanced current injection and high electroluminescence efficiency as compared with a Sm cathode. The maximum current efficiency of the top-emitting OLEDs with a Sm/Ag cathode is 9.9 cd/A, much greater than 4.9 cd/A obtained from the top-emitting OLEDs with a Sm cathode. The improved performance can be attributed to the balance between optical transparency and electrical conductivity of the Sm/Ag cathode.

The quasi-three-level 908-nm continuous-wave laser emission under direct diode laser pumping at 880 nm into emitting level 4F3/2 of Nd:YLF have been demonstrated. An end-pumped Nd:YLF crystal yielded 4.7 W of output power for 11.8 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 43.3%. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing 4F5/2 level, are given in order to prove the advantages of the 880-nm wavelength pumping.

We present an efficiency Nd:LiYF4 (Nd:YLF) laser operating at 1313 nm pumped directly into the emitting level 4F3/2. At the incident pump power of 10.3 W, as high as 3.1 W of continuous-wave output power at 1313 nm is achieved. The slope efficiency with respect to the incident pump power was 36.1%. To the best of our knowledge, this is the first demonstration of such a laser system. Comparative results obtained for the pump with diode laser at 806 nm, into the highly absorbing 4F5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.

Aging is associated with exacerbated brain injury after ischemic stroke. Herein, we explored the possible mechanisms underlying the age-associated exacerbated brain injury after ischemic stroke and determined whether therapeutic intervention with anesthetic post-conditioning would provide neuroprotection in aged rats. Male Fisher 344 rats (young, 4 months; aged, 24 months) underwent 2h of middle cerebral artery occlusion (MCAO) followed by 24-h reperfusion, with or without sevoflurane post-conditioning for 15 min immediately at the onset of reperfusion. Compared with young rats, aged rats showed larger infarct size, worse neurological scores and more TUNEL-positive cells in the penumbral cerebral cortex at 24h after MCAO. However, edema formation and motor coordination were similar in both groups. Sevoflurane reduced the infarct size, edema formation, and TUNEL-positive cells, and improved the neurological outcome in young rats but not in aged rats. Molecular studies revealed that basal expression of the anti-apoptotic molecule B-cell lymphoma-2 (Bcl-2) in the brain was lower in aged rats compared with young rats before MCAO, while basal expression of the pro-apoptotic molecule Bcl-2-associated X protein (Bax) showed similar levels in both groups. MCAO reduced Bcl-2 expression and increased Bax expression in both groups; however, Bax increase was more pronounced in aged rats. In young rats, sevoflurane reversed the above MCAO-induced changes. In contrast, sevoflurane failed to enhance Bcl-2 expression but decreased Bax expression in aged rats. These findings suggest that aging-associated reduction in basal Bcl-2 expression in the brain contributes to increased neuronal injury by enhancing cell apoptosis after ischemic stroke. Sevoflurane post-conditioning failed to provide neuroprotection in aged rats, probably due to its inability to increase Bcl-2 levels and prevent apoptosis in the brain.

Mg 0.20 Zn 0.80 O films have been prepared on quartz substrates by using radio frequency (RF) magnetron sputtering, and metal–semiconductor–metal (MSM) structured photodetectors have been fabricated on the Mg 0.20 Zn 0.80 O films employing interdigital Au as metal contacts. We have investigated the effects of electrode spacings on the properties of Mg 0.20 Zn 0.80 O MSM photodetectors. It was shown that both of dark currents and responsivities of the devices will decrease with the increasing electrode spacing at the same bias. It was thought that the resistance and the depletion region between the electrodes play important roles in the devices, and the physical mechanism can be explained by a straightforward qualitative model.

The objective of the present study is to elucidate the effects of the application of cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant chlorine dioxide on the occurrence of banana fusarium wilt disease and soil bacterium community.Under the field cultivation conditions, the Biolog and T-RFLP method was used to investigate the soil bacterium diversity and community features in different treatments at different periods.The results show that both cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant could reduce disease index of banana fusarium wilt disease significantly, the highest control effect could reach 60.82% with the combined application of these two methods. The result of Biolog eco plate shows that the application of cake fertilizer fermentation fluid with antagonistic bacteria could improve soil microbial AWCD (average well color development) and population uniformity, the use of soil disinfectant significantly reduced the soil microbial population's abundance and the uniformity. Principal component analysis shows that the soil microbial population using carbon source had an increasing trend throughout the banana growing season, the main carbon sources in the early stage were amino acids, carboxylic acids, amphiphilic compounds and carbohydrates, and the increased main carbon sources in the later stage were carboxylic acids and amphiphilic compounds. Soil bacterial diversity analysis by T-RFLP shows that the treatments of cake fertilizer fermentation fluid with antagonistic bacteria had the highest bacterial TRFs (Terminal restriction fragment) fragments, which resulted from the increase of Flavobacterium, Pseudomona and Lactobacillus population in the soil.The application of cake fertilizer fermentation fluid with antagonistic bacteria combining soil disinfectant could increase antagonistic microorganisms species, enhance soil microbial diversity, improve soil microbial ecological structure on the basis of reducing pathogen in soil, finally achieve the goal of improving the control effects of banana fusarium wilt disease.

Up-conversion of 45PbF(2)-45GeO(2)-10WO(3) oxy-fluoride glasses co-doped with Yb3+ and Er3+ ions were prepared by fusion method through melting at 1223 K and then annealing at 653 K for 4 h. Transmittance of the undoped host glass was beyond 73% in a range of 0.6-2.5 mu m and the co-doped glasses still provided good transmittance beyond 50%. Refractive indices of the host and co-doped glasses were 1.517 and 1.650, respectively. Blue, green and red fluorescence spectra were observed in a range of 400-700 nm under 980 nm diode laser excitation. Up-conversion spectra at about 410, 518, 530and 650 nm were assigned to the 4f electron transitions of H-2(9/2) -> I-4(15)/(2), H-2(15/2) -> I-4(15/2) S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) of Er3+ ion, respectively. The mechanism of energy transfer between Yb3+ and Er3+ ions in the glass was analyzed. Raman shift shows the non-radiative relaxation of the glass sample is low.

In the case of in-pile meltdown, the reaction between the UO2 fuel and zircaloy cladding will cause the formation of a series of new phases and the diffusion of oxygen from UO2 to zircaloy, which has great influence on the movement of phase interface during the cladding-stream reaction. This paper presents a method to calculate the kinetics of oxidation of the cladding-stream reaction in this condition.

Silicate garnet phosphors (Lu[Formula: see text]Ce[Formula: see text]Ca[Formula: see text]Mg2Si3O[Formula: see text] with [Formula: see text], 0.05, 0.1, and 0.15 were prepared by high-temperature solid-state reaction in a reducing atmosphere. The crystal structure, photoluminescence and luminescence of the phosphors were investigated. The optimum excitation peak wavelength of the phosphors ranged from 450[Formula: see text]nm to 490[Formula: see text]nm, matching the emission spectra of a blue light-emitting diode chip. The phosphors emit orange-red light after excitation that can be tuned from 589[Formula: see text]nm to 597[Formula: see text]nm by changing the concentration of calcium ions. In addition, their emission made them suitable for use in warm-white LEDs with a high-color rendering index.

Sr3SiO5:Eu[Formula: see text] phosphors were synthesized rapidly through a microwave sintering method with the presence of activated carbon powder. The detailed composition and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The influences of sintering time, fluxing agent (BaF[Formula: see text] content and rare earth ion doping concentration on its photoluminescence (PL) properties were also investigated. It was clear in PL spectra that a broad emission band peaking at 570[Formula: see text]nm was obtained in as-prepared phosphors under a blue light excitation. Meanwhile, non-radiative transitions between Eu[Formula: see text] ions in the Sr3SiO5 host had also been demonstrated to be attributable to dipole–dipole interactions, and the critical distance calculated by the quenching concentration was estimated to be 10.56 Å. The samples were uniform in diameter and regular in morphology. In other words, the Sr3SiO5:Eu[Formula: see text] phosphors possessed a potential application for white light emitting diodes (LEDs).

Y2O3:Eu3+ phosphors co-doped with different metal cations (Li+, Na+, K+, Mg2+, Ca2+) are prepared by the gel-combustion method with Y2O3, Eu2O3, and R(NO3) x (R = Li, Na, K, Mg, Ca) serving as raw materials and glycine as fuel, calcined at 1000 °C for 2 h. The synthesized Y2O3:Eu3+ phosphors doped with different metal cations and doping ratios are characterized by x-ray diffractometry (XRD), fluorescence and phosphorescent spectrophotometer. The co-doping metal cations are advantageous to the development of Y2O3:Eu3+ lattice. All the samples can emit red light peaked at 611 nm under 254-nm excited. The luminescence intensities of co-doping samples are increased because the cations increase the electron transition probability of Eu3+ from 5D0 level to 7F level. The fluorescence lifetime of Eu3+ (5D0 → 7F2) is increased by doping metal cations.

Er[Formula: see text]/Yb[Formula: see text] co-doped Y2O3 transparent ceramics were fabricated by vacuum sintering method. The Y2O3: Er[Formula: see text]:Yb[Formula: see text] nonopowders were prepared by co-precipitation method in advance. The morphology of powders and ceramics as investigated. The powders exhibited well dispersive condition with 100[Formula: see text]nm in diameter. The compactness of ceramics increased obviously with the increasing temperature. No pore was found in the ceramic sintered at [Formula: see text]C. The ceramic samples showed intense near infrared luminescence peaking at 1535[Formula: see text]nm under the excitation of 980[Formula: see text]nm lasers, assigned to the [Formula: see text] transition of Er[Formula: see text]. The intense up-conversion emissions were observed under the excitation of 980[Formula: see text]nm and 1550[Formula: see text]nm lasers.

The precursors were synthesized by a co-precipitation method with the solutions of mixed nitrates as starting materials and ammonium bicarbonate as precipitator. The Yb3+:Y2O3 ultrafine powders were prepared by sintered precursors at various temperatures. XRD, TG-DTA, SEM and the fluorescence spectra analysis were employed to characterize the Yb3+:Y2O3 ultrafine powders. The results showed that the powders are less-aggregative and well-dispersive with diameters about 100~200nm. The luminescence spectrum is consisted of three peaks at 976nm, 1030nm and 1075nm respectively under excitation of 514nm which are attributed to transition of Yb3+ 2F5/2→2F7/2.

Nanosized green phosphor LaPO 4: Ce 3+, Tb 3+ has been synthesized by microwave-assisted co-precipitation method. The morphology, crystal structure and photoluminescence properties have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The lanthanum phosphate phosphors with monoclinic crystal structure and fine crystallinity and dispersibility were synthesized at 900°C for 1 h and the particle size of the phosphors is ∼ 100 nm. The strongest photoluminescence emission peak is located at 543 nm due to the (5D4→7F5) transition of Tb 3+ ion. The experimental results indicate that nanosized green phosphor 40% Ce 3+ and 20% Tb 3+ doped LaPO 4 synthesized by microwave-assisted co-precipitation method is a beneficial phosphor for high resolution display devices.

Y 2 O 3: Eu 3+, Tb 3+ nanopowders were prepared by co-precipitation method with NH 4 HCO 3 as precipitant. The nanopowders with different calcined temperatures and Eu 3+/ Tb 3+ doped ratio were characterized by X-ray Diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The results showed that the nanopowders calcined at 1100°C for 2 h had a uniform distribution, high purity and good dispersibility. The particle size was in the range of 60–80 nm. The excitation spectra of Eu 3+/ Tb 3+ co-doped phosphors were wide. The phosphors could emit the green light at the peak of 543 nm and the red light at the peak of 611 nm simultaneously under 276 nm or 300 nm excited. Because of the energy transfer between Tb 3+ and Eu 3+, the 543 nm emission of Tb 3+ ion was weakened while the 611 nm emission of Eu 3+ enhanced. The emissive colors of Y 2 O 3: Eu 3+, Tb 3+ nanopowders could be adjusted from yellow-green to orange-red by changing the Eu 3+/ Tb 3+ doping ratio.

The paper presents investigation results on surface modification influence of monocrystalline zinc sulfide substrates on their optical transmission and photoluminescence spectra. One of characteristic peculiarities of the samples considered is the presence of wide 2.5- 3.2 eV structureless irradiation band at CdS fundamental absorption region. Apart from this, absolute transmission decreases and transmission edge shifts into low-energy region of ~0.1 eV upon surface modification. Observed peculiarities of CdS optical properties can be explained by quantum-scale effects in nanocrystalline modified surface layer, experimentally detectable with atomic force microscopy.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper electron trapping optical storage materials CaS: Eu, Sm was prepared by high temperature solid state method. XRD analysis indicates that the sample obtained is with face-centered cube structure. with a lattice parameter of 5.694A. Optical properties of CaS: Eu, Sm were studied. Excitation spectrum shows that the material can be excited by ultraviolet and visible light. The excitation peaks are at 250-300nm and 450-550nm respectively ranging from 250-550nm. Emission spectrum is composed of three peaks at 567nm, 603nm and 650nm respectively. Photo-stimulation excitation spectrum is a broadband spectrum between 800nm and 1600nm peaking at about 1200nm. Photo-stimulated luminescence peak is at 635nm.

In this paper, rare earth europium ion doped SrO-B 2 O 3 -Al 2 O 3 -SiO 2 glasses were prepared. The batches were melted under an ambient atmosphere and reheated under a reducing atmosphere. The glass after being reheated in the reducing atmosphere show long after glow phosphorescence resulted from 5d-4f transition of Eu 2+ ion . Whereas the glasses melted under an ambient atmosphere show luminscence peaks attributed to the 5 D i → 7 F j of Eu 3+ ion.

In this paper, we prepared SrAl 2 O 4 :Eu 2+ ,Dy 3+ long persistence phosphorescence enamel coatings by using SrAl 2 O 4 :Eu 2+ ,Dy 3+ phosphor powders and glass frits and organic vehicle. The glass frits were specially prepared to fit the SrAl 2 O 4 :Eu 2+ ,Dy 3+ . The prepared phosphorescence enamels were found to have very bright long lasting phosphorescence after being excited by the ordinary fluorescent lamp or sunlight. The emission can be seen even 12h after removal of the exciting soruce. The emission shows a broad band peaking at 520nm resulted from the transition of 4f-5d of Eu 2+ ions in SrAl 2 O 4 :Eu 2+ ,Dy 3+ . The phosphorescence enamels can be used as energy saving display in various applications.

We demonstrated a model to realize the growth of indium–silver alloy nanocrystals in borosilicate glass by sol–gel method plus a controlled atmosphere. The presence of spherical indium–silver alloy nanoparticles with 5 nm average grain size and good dispersed form in borosilicate glass was confirmed by transmission electron microscopy imaging. Reduction of indium–silver ions to indium–silver alloy neutral nanocrystals was revealed through X-ray powder diffraction and X-ray photoelectron spectra (XPS). Remarkably, indium–silver alloy nanocrystals borosilicate glass exhibited fluorescence at around 423 nm which nominated it as the candidate glass for laser sources, nonlinear media and photonic applications.

The low-temperature combustion synthesis (LCS) method is the most popular method for the synthesis of ultrafine oxides and compound oxides. A kind of Er - Y - Pb - Na quaternary fluoride sensitive to 1.55 μm was synthesized by the LCS method and the synthesis conditions were optimized with orthogonal experiments. Intense upconversion emissions at 522 nm, 541.4 nm and 654.7 nm corresponding to the 2 H 11/2, 4 S 3/2 and 4 F 9/2 transitions to the 4 I 15/2 ground state were observed when excited by CW laser radiation at 1.55 μm. The effect of the carbamide amount on the phase formation and the luminescence intensity was analyzed. The product is of uniform particle size of ca. 40 nm, which is very outstanding for its reutilization in the infrared detection field.

In this paper glass frits were prepared by the melting and quenching method. The SrAl2O4:Eu2+,Dy3+ was incorporated in the glass frits by firing them on a glass substrate. The photo luminescence was measured in terms of excitation and emission spectra. Effects of firing temperature on the phosphorescence persistence were measured.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The β-BaB2O4 thin films were prepared by the sol-gel method. The nucleation agent was added in favor of crystallization of the thin films. The second harmonic generation (SHG) was measured by using a Q-switched Nd:YAG laser.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The spacers in liquid crystal display box often use plastic microspheres, glass fiber and glass microspheres. Plastic microspheres are easy aging and become brittle, glass fiber is easy overlapping and add the thickness of box, so it is important to research glass microspheres with high property. The chemical stability must be good for glass microspheres used as spacers, and conductive alkali metal ions can not present when it is using. The size of particles must be uniform. The author studied ZnO-B 2 O 3 -SiO 2 glass without alkali and its chemical stability is excellent. The microspheres was obtained by the powder technology, and a gasification equipment was used to insure the high dispersion of particle. A negative pressure equipment was adopted in the collection equipment. The glass microspheres with elliptically below 3% were prepared. We select the spacers material used in liquid crystal, its size is about 7 +/- 0.05 mm by screening and flotation. The glass spheres without alkali and having high chemical stability.

The chemical stability for optical glass is one of the problems that be cared for by people very long time. The glass is eroded and form erosion spot on the surface because glass often touch with the solution of acid alkali salt during fabricating using and storing. Optical instrument eroded by dump also form spot and watermark because of long time using. So the imaging quality of optical instrument is influenced in different degree. Especially various flint glass used in export camera lens, its bad chemical stability reduce competitiveness at international market. It is necessary that the chemical stability of flint glass be improved. The factors that influence the glass chemical stability are internal structural and surface strength. The aim is improving the chemical stability of 575/413 optical class through adjusting glass component and changing its internal structure.

(beta) -BaB2O4 is a remarkable non-linear optical material for its large second harmonic generation coefficients and wide transparent range. Glass ceramics as a kind of functional materials was recently paid more attention because large size products can be more easily obtained and their properties can be compared with those of corresponding single crystals. In this paper (beta) -BaB2O4 glass ceramics was prepared by melting BaCO3 and H3BO3 and following heat treatment the bulk samples. DTA, XRD and FTIR were used to investigate the phase separation and crystallization process of (beta) -BaB2O4 second harmonic generation of glass (beta) -BaB2O4 glass ceramics were studied.

Er2O3 doped fluogermanate glasses have been prepared by the melting method. The optical absorption spectra and fluorescence emission spectra of the glasses were measured. The influence of Er3+ concentrations on the fluorescence emission intensity was discussed. Green upconversion emission was observed for the Er3+ doped fluogermanate glass.

Sol-gel process was adopted to prepare Er3+ and Yb3+ codoped SiO2 glass DTA and FTIR were carried out to investigate the structure change from gel to glass. The fluorescence emission spectra were measured. The green upconversion emission was obtained for the Er3+- Yb3+ codoped sol-gel SiO2 glass. The energy transfer between Er3+ ion and Yb3+ ion for the upconversion emission was discussed.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Glass microspheres with the property of high reflection has become a trend as a new type laser cooperative target, which is installed on the surface of a flyer, and have little volume, high weight, the goal is to add the flyer surface reflection to laser signs when detect and follow the tracks of a flyer. In this paper, the technological theory used as laser cooperative target was discussed. The special technological process was introduced. The properties of glass microspheres as laser cooperative target obtained are as follows: size/55 - 80 micrometers ; laser divergent angle/22.2 (mrd); reflecting ratio/18(%); effective action angle/+/- 70 ( degree(s)).

Sol-gel dip coating method was adopted to prepare Rhodamine-6G doped SiO2-TiO2 thin films. Effects of MTMS/TEOS ratio on the crack of the thin films during drying stage were studied. The cracking was greatly decreased with the increase of MTMS/TEOS ratio. Crack free thin films were obtained for the samples with MTMS/TEOS greater than 0.75. The optical absorption and fluorescence spectra of the thin films were recorded. The refractive index increases linearly with the increase of TiO2 content (20, 40, 60 mol%). The third order nonlinear susceptibility of the Rhodamine-6G doped SiO2-TiO2 thin films is (chi) (3) approximately equals 10-9 esu measured by the generate four wave mixing technique.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Using high-resolution transmission electron microscopy, we characterized the structures of {101¯2} deformation twin boundaries (TBs) in cobalt and found that TBs consist of {101¯2} coherent twinning boundaries and basal-prismatic interfaces (BPs or PBs). According to these structural features, the propagation of {101¯2} twins cannot be simply accomplished through the glide-shuffle mechanism of twinning dislocations. Correspondingly, two migration mechanisms of such TBs are proposed based on dislocation theory. In addition, abundant basal stacking faults are observed experimentally to connect with TBs, and this phenomenon is ascribed to the release of residual dislocations resulting from the migration of the BPs and PBs.

We present a laser architecture to obtain continuous-wave orange–yellow radiation at 589 nm. A 808 nm diode-pumped the Nd:GdVO4 crystal emitting at 1341 nm. A part of the pump power was then absorbed by the Nd:GdVO4 crystal. The remainder was used to pump the Nd:YLiF4 (Nd:YLF) crystal emitting at 1053 nm. Intracavity sum-frequency-mixing at 1341 and 1053 nm was then realized in a LiB3O5 (LBO) crystal to produce orange–yellow radiation. We obtained a continuous-wave output power of 352 mW at 589 nm with a pump laser diode emitting 18.4 W at 808 nm.