sol-gel法制备ZAO薄膜的结构与光学性能研究

采用溶胶—凝胶法在普通玻璃衬底上制备了ZAO(ZnO:A1)薄膜,利用XRD、SEM、紫外—可见光谱和光致发光光谱对所制备的AZO薄膜进行了表征,研究了ZAO薄膜的结构和光学性能.结果表明:ZAO薄膜的微晶晶相与ZnO一致,且具有c轴择优取向;ZAO薄膜在可见光区的透过率超过了88％,在350～575 nm范围内有强的...     

有机半导体ADN的DFT理论计算研究

采用密度泛函理论(DFT)方法对9,10-二(2-萘基)蒽(ADN)进行了B3LYP/6-31G水平上的分子结构优化、红外光谱、Raman光谱、紫外-可见光谱、分子前线轨道、Mulliken电荷等理论计算。研究结果表明:理论计算结果与实验数据吻合得较好,对IR、THz、UV-Vis吸收光谱和Raman散射光谱中的特征峰进行了归属,发现ADN在0.1～10 THz波谱范围内有5个明显的吸收峰,分别位于1.08、2.52、4.44、5.64及6.60 THz,其中5.64 THz的吸收是最强的,它是由萘环面外弯曲及蒽环面内摇摆振动产生的。ADN在紫外光波段有三个吸收峰,分别对应于386.34、352.98及352.50nm,其中386.34 nm的紫外吸收峰最强。ADN理论计算能隙值为3.516 eV,比实验值3.2 eV略高。ADN的Mulliken电荷计算表明,所有H原子的Mulliken电荷皆为正电荷,C原子Mulliken电荷与其具体的化学环境相关。     

可溶性纳米PANI-DBSA复合物光电性能研究

通过乳液聚合法制备纳米聚苯胺,使用十二烷基苯磺酸(DBSA)作为掺杂剂,在聚苯胺链上引入直链烷基,得到可溶性纳米聚苯胺(PANI-DBSA)复合物。研究了DBSA含量对PANI-DBSA复合物溶解度和电导率的影响,及制备过程中聚苯胺的生成和最终产物的紫外-可见光特征。结果表明:聚苯胺颗粒分散性好,粒径为20～100nm,当DBSA与苯胺单体摩尔比为3.0时,聚合物在甲苯中的溶解度最高为3.76%,当DBSA与苯胺单体摩尔比为1.0,聚合物导电性最好,电导率为250.4S/m。PANI-DBSA复合物在波长300～800nm具有良好的吸收性能。     

Measurement of phenols dearomatization via electrolysis: The UV-Vis solid phase extraction method

Dearomatization levels during electrochemical oxidation of p-methoxyphenol (PMP) and p-nitrophenol (PNP) have been determined through UV-Vis spectroscopy using solid phase extraction (UV-Vis/SPE). The results show that the method is satisfactory to determine the ratio between aromatic compounds and aliphatic acids and reaction kinetics parameters during treatment of wastewater, in agreement with results obtained from numerical deconvolution of UV-Vis spectra. Analysis of solutions obtained from electrolysis of substituted phenols on antimony-doped tin oxide (SnO₂Sb) showed that an electron acceptor substituting group favored the aromatic ring opening reaction, preventing formation of intermediate quinone during oxidation.     

基于荧光及紫外光谱法对虾青素与乳清蛋白相互作用的研究

本研究采用分子自组装技术制备虾青素/乳清蛋白纳米复合物,并探究虾青素（Astaxanthin,AST）与乳清蛋白（Whey Protein）之间的分子相互作用机制。选用乳清蛋白（α-乳白蛋白、β-乳球蛋白、浓缩乳清蛋白、牛血清蛋白）与虾青素自组装,通过控制水相蛋白质溶液与有机相虾青素溶液的比例,分别可控形成H聚集体或J聚集体虾青素/乳清蛋白纳米复合物（H/J Aggregates Astaxanthin/Whey Protein Nanocomplexes）。通过动态光散射仪（Dynamic Light Scattering,DLS）测定虾青素/乳清蛋白纳米复合物的粒径均在150~430 nm之间,多分散性指数（Polydispersity Index,PDI）表明分散性良好,电位在?12~?1 mV之间;采用透射电子显微镜（Transmission Electron Microscope,TEM）观察成功制备出的H聚集体或J聚集体虾青素/乳清蛋白纳米复合物呈边缘清晰光滑的近球形结构;紫外可见光谱表明4种蛋白质构建的H聚集体或J聚集体虾青素/乳清蛋白纳米复合物中虾青素H聚集体最大吸收波长λ_max由虾青素单体的λ_max480 nm蓝移至388 nm,虾青素J聚集体最大吸收波长λ_max光谱红移,并显示出519和556 nm左右的并肩峰;通过荧光光谱分析表明由于虾青素聚集体特定的结构使形成的虾青素/乳清蛋白纳米复合物的荧光强度都明显增强,乳清蛋白中疏水性氨基酸及疏水性区域暴露。本研究从虾青素及其聚集体的水分散性和乳清蛋白载体特性两方面探究,为其后续在食品药品领域的开发及应用提供理论依据。     

Fabrication and photocatalytic property of ZnO nanorod arrays on Cu2O thin film

ZnO nanorod arrays were fabricated on Cu₂O thin film by a simple low-temperature liquid-phase-deposition method. The samples were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM). The UV-Vis spectroscopy showed that the obtained sample was able to absorb a large part of visible light (up to 650 nm). Their photocatalytic activities were investigated by degradation of dye methylene blue (MB) under UV-Vis and visible light irradiation. It was found that the photocatalytic activity of the ZnO/Cu₂O NRs was higher than the ZnO/ZnO NRs under UV-Vis light. In a word, Cu₂O played an important role in enhancing the photocatalytic activity of the ZnO/Cu₂O NRs.     

基于雷达图与紫外-可见分光光度法建立鱼汤挥发性风味评价方法及其应用

目的建立感官评价与浓度评价相结合的鱼汤挥发性风味综合评价斱法,幵应用于鱼汤配料配斱研究。方法应用感官评分表、雷达图及紫外-可见分光光度法(ultraviolet-visible spectrophotometry, UV-Vis)等可视化手段将感官评价与浓度评价结合建立鱼汤挥发性风味评价斱法,其中感官评价从鱼腥味、油脂香、豆腥味、生姜味、大蒜味、清香、综合7个感官剖面开展幵应用雷达图分析,浓度评价以风味萃取物的UV-Vis吸收值考察。结果基于所建立的评价斱法,鱼肉250 g,大豆油、生姜、大蒜添加量为鱼肉重的9%、1.2%、3.5%时,所制作的鱼汤风味最佳。结论本研究建立的斱法直观、快捷、简单,可操作性强,兊服了单一感官或浓度评价的不足,可拓展应用于新产品开发或新工艺的研究。     

Investigation of structural,optical, magnetic,and dielectric properties of calcium hexaferrite synthesized in presence of Azadirachta indica and Murraya koenigii leaves extract

M-type calcium hexaferrite- CaFe₁₂O₁₉ (CaM) has been prepared in presence of Azadirachta indica, and Murraya koenigii leaves extracts, followed by calcination at 650 °C for 3h. It was observed that the presence of phytochemicals in both leaves extract plays a vital role in deciding the structural, optical, microstructural, magnetic, and dielectric properties of prepared CaM hexaferrites. Prepared samples were characterized using FT-IR, XRD, UV–Vis, SEM, VSM, and dielectric measurements. FTIR, UV– Vis, and antioxidant assay confirmed the presence of phenolic content and antioxidant property of plant extract. This further resulted in the formation of a pure hexagonal phase as revealed by the XRD analysis. The surface morphology of prepared ferrites modified through this greener route was illustrated by the spongy appearance of ferrites in SEM micrographs.The saturation magnetization for the CaM powder prepared using Murraya koenigii leaves extract is 11.78 Am²/kg, while that prepared from Azadirachta indica leaves extract is 3.56 Am²/kg. Both samples show a magnetically soft nature, with a multidomain structure. The energy bandgap was also observed to be 2.01 eV. Moreover, the calcium ferrite synthesized by Murraya koenigii leaves had ε’_max ～ 25 and that synthesized in presence of Azadirachta indica leaves had ε’_max ～ 200 at ～20 Hz.     

Relationship concerning the nature and concentration of Fe(III) species on the surface of TiO2 particles and photocatalytic activity of the catalyst

There have been contradictory results concerning the effect of doping TiO₂ with Fe(III) upon its photocatalytic activity. We believe that this is due to the method used in adding the Fe(III) to TiO₂. This paper addresses this issue by using a precise adsorption process for loading stable aqueous suspensions (sols) of TiO₂ doped with Fe(III). In this manner, we control the speciation of Fe(III) on the surface of TiO₂ and subsequently use these loaded sols to produce stable thin-film photocatalysts. Adsorption isotherms for these systems at different pH (2.0 and 2.5) values showed that both pH and the concentration of Fe(III) in solution influence the adsorption density of Fe(III), the stability of the resulting sols, and the speciation (degree of polymerization) of Fe(III) ions on the surface of the TiO₂ nano-particles. UV-Vis spectroscopy on selected systems was the technique employed to confirm these results. The pore structure of the resulting gels (xerogels) prepared from these sols, as well as thermal stability of porous materials prepared by firing the xerogels have been determined by measuring N₂ adsorption as a function of firing temperature. Thermal analysis (TG–DTA) studies on xerogels obtained from some of these systems showed that the presence of Fe(III) species on the TiO₂ retards the conversion of anatase into rutile and therefore increases the thermal stability of the gel microstructure. Lastly, porous films, resulting from the casting of the sols on glass rings and subsequent firing, were used in photocatalytic studies. In the presence of UV light, these supported films were capable of degrading ethanol in the gas phase. While photocatalytic activity for Fe(III) loaded TiO₂ films is less than for TiO₂ films without Fe(III), the speciation of Fe(III) on the surface directly influences the behavior of the intermediate—acetaldehyde—formed in this reaction. Since we have only evaluated the effect of iron speciation on the degradation of ethanol, other target species may be influenced either advantageously or deleteriously depending upon the state of Fe(III) on the surface of TiO₂ photocatalysts.     

紫外-可见光谱水质检测系统的多束LED光纤耦合研究

针对紫外-可见光谱水质检测系统单个LED光源输出功率低、光束质量差的问题,提出了一种多束紫外LED光源与光纤合束耦合的结构设计方案.运用ZEMAX光学分析软件开展了仿真设计研究,针对紫外LED光源与光纤耦合发散角较大的问题,设计了非球面准直透镜,准直后发散角为0.403 mrad;针对光束尺寸与光纤的匹配问题,进行了消色差双分离聚焦耦合透镜的设计.实验结果表明,合束LED光束汇聚的弥散斑的RMS尺寸为186.412 μm,GEO点尺寸为290.071 μm,光束中95％以上的能量集中在300μm以内,实现了多束LED光源与光纤的高效耦合.