氧化铁电极的半导体性能和光电化学——Ⅳ、阳极形成及热形成氧化铁电极的光电化学实验研究

本文指出, 由于热形成氧化铁电极光电流响应的瞬态性质, 所以正用锁定放大器测量出的数值大大超过其代数平均值。阳极形成铁钝化膜的光电响应与热形成氧化铁的相类似, 但有一定差别。目前的实验水平尚不足以监测钝化膜形成过程中的结构性质。但实验证明膜基本形成后, 在理想情况下, 光电流与膜厚在一定范围内成正比。在膜基本形成前, 则光电流之值较大, 偏离正比关系。     

High-speed simultaneous ion-exclusion/cation-exchange chromatography of anions and cations on a weakly acidic cation-exchange resin column

The simultaneous ion-exclusion/cation-exchange separation column packed with a polymethacrylate-based weakly acidic cation-exchange resin of 3 microm particle size was used to achieve the simultaneous high-speed separation of anions and cations (Cl(-), NO3(-), SO4(2-), Na(+), K(+), NH4(+), Ca(2+) and Mg(2+)) commonly found in environmental samples. The high-speed simultaneous separation is based on a combination of the ion-exclusion mechanism for the anions and the cation-exchange mechanism for cations. The complete separation of the anions and cations was achieved in 5 min by elution with 15 mM tartaric acid-2.5 mM 18-crown-6 at a flow-rate of 1.5 ml/min. Detection limits at S/N=3 ranged from 0.36 to 0.68 microM for anions and 0.63-0.99 microM for cations. This method has been applied to the simultaneous determination of anions and cations in several environmental waters with satisfactory results.     

Change of sheet resistance of high purity alumina ceramics implanted by Cu and Ti ions

High purity alumina ceramics (99% Al₂O₃) was implanted by copper ion and titanium ion in a metal vapour vacuum arc (MEVVA) implanter, respectively. The influence of implantation parameters was studied varying ion fluence. The samples were implanted by 68 keV Cu ion and 82 keV Ti ion with fluences from 1 × 10¹⁵ to 1 × 10¹⁸ ions/cm², respectively. The as-implanted samples were investigated by scanning electron microscopy (SEM), glancing X-ray diffraction (GXRD), scanning Auger microscopy (SAM), and four-probe method. Different morphologies were observed on the surfaces of the as-implanted samples and clearly related to implantation parameters. For both ion implantations, the sheet resistances of the alumina samples implanted with Cu and Ti ion fluences of 1 × 10¹⁸ ions/cm², respectively, reached the corresponding minimum values because of the surface metallization. The experimental results indicate that the high-fluence ion implantation resulted in conductive layer on the surface of the as-implanted high purity alumina ceramics.     

武昌珞珈山大气环境监测研究

为了了解珞珈山大气环境质量现状及其时空变化规律，在珞珈山周围设立了５个大气监测采样点，进行一年多的大气环境监测，并对所取得的数据进行分析评价．结果是，飘尘．ＳＯ２和ＮＯｘ符合国家大气环境质量标准ＧＢ３０９５－８２所规定的二级标准．     

Spectroscopic properties of Er<Superscript>3+</Superscript> in Sc:LiNbO<Subscript>3</Subscript> crystal

The results of Er³⁺ ion spectroscopic analysis in Sc:LiNbO₃ crystals were reported. The line strengths from the ground state to the excited state were evaluated from the measured unpolarized absorption spectrum and analyzed by using standard Judd–Ofelt theory. For Sc(3 mol. %):Er (1 mol. %):LiNbO₃ crystal, the obtained intensity parameters are: Ω₂=3.72×10^-20 cm², Ω₄=1.07×10^-20 cm², and Ω₆=0.98×10^-20 cm². The fluorescence spectra and microsecond time-resolved spectra were investigated in the visible region. The excited state absorption transition strengths at 800 nm excitation were evaluated based on Judd–Ofelt theory. The results obtained here were compared to results from other research on Er:LiNbO₃ crystals. PACS 71.20.Eh; 77.84.Dy; 42.70.Hj; 42.62.Fi; 42.65.Ky     

ZFC的模型的上限序数的一个性质

S1 引言 Forcing方法假设存在ZFC的一个可数可传的模型M。记满足αM的最小序数α为,显然M中一切序数所成的集合即。由于M是ZFC的模型,故应具有某些性质。本文证明了它满足关系,故为ε数或1级关键数,进而证明了是H级关键数(H为任意自然数)。文中的记号等引用。     

Conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural catalyzed by sulfonic acid-functionalized carbon material with high strong-acid density in γ-valerolactone

Research on Chemical Intermediates - A carbonaceous solid acid catalyst with high strong-acid density was synthesized by facile functionalization of a biomass-derived mesoporous carbon with...     

工艺因素对离子束增强沉积氮化硅薄膜组成与结构的影响

本世纪８０年代以来，利用各种表面技术陶瓷材料涂覆于金属零件表面的研究发展很快，离子束增强沉积技术以其突出的优点更受到重视，利用这种技术合成陶瓷薄膜是一种新的物理气相沉积方法，而沉积薄膜的质量，性能和成膜速度都会受到工艺因素的影响，由于氮化硅陶瓷的硬度高，韧性和高温稳定性都比较好，是一种相当理想的耐磨材料，且其还有一定的自润滑性，因此，着重研究了氮离子束流和束压，氮离子与硅原子在基片上的达比，以及不     

Production of acetic acid from liquid crystal display waste by use of a hydrothermal method

Because of the large quantity of liquid crystal displays (LCDs) in use, the volume of waste LCDs is ever-increasing, causing growing concern about their effective treatment. Polarizers are among the most important functional films used in LCDs and are mainly treated by incineration after being discarded. In this study, they were used to produce acetic acid under the hydrothermal conditions; this could aid development of a new environmentally sustainable process for treatment of waste polarizers. The experiment was performed in a 5.7-ml bath reactor heated by use of a salt-bath. The liquid product was analyzed by high-performance liquid chromatography. The effect of reaction temperature, reaction time, and oxidant on acetic acid production was investigated. Results showed that the yield and selectivity for acetic acid initially increased with increasing reaction temperature, reaction time, and H₂O₂ supply but then decreased within the ranges of the experiments performed. The highest acetic acid yield of 33.4 %, with selectivity of 26.7 % based on carbon, was obtained by hydrothermal treatment of waste polarizer at 350 °C for 5 min with 0.6 ml H₂O₂.