The effect of titanium dioxide-supported CdSe photocatalysts enhanced for photocatalytic glucose electrooxidation under UV illumination

The wetness impregnation method was used to synthesize 0.1% CdSe/TiO₂ photocatalysts with different atomic molar ratios (90–10, 70–30, 50–50, and 30–70). These catalysts were characterized by XRD, SEM-EDX and mapping, TEM-EDS, UV–VIS spectroscopy, fluorescence spectroscopy, XPS, TPR, TPO, and TPD analyses. Cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analyses were performed to examine the photocatalytic activity for photocatalytic fuel cells (PFCs) in glucose solution in the dark and under UV illumination. The characterization analyses revealed that anatase TiO₂ formed the catalyst and electronic structure and surface properties changed when doped with metal. The photocatalytic glucose electrooxidation (PGE) results demonstrate that the 0.1% CdSe(50-50)/TiO₂ catalyst has higher photocatalytic activity, stability, and resistance than other catalysts both in the dark (2.71 mA cm^?2) and under UV illumination (7.20 mA cm^?2). These results offer a promising new type of photocatalyst for PFC applications.     

基于Selenium的Web自动化测试解释器

Selenium自动化测试工具在测试领域已经被广泛应用.使用时它需要依赖其它编译器或解释器才能执行测试.一方面让测试人员需要熟练的编程技术才能使用,另一方面让测试开发难度过高.为了降低自动化测试门槛,针对Web自动化测试设计了一种基于Selenium的解释器.首先深入剖析Selenium的测试原理,依据它测试接口的使用状况对主要的测试类构建依赖关系,然后根据Web程序的测试需求构建解释器的各个模块.参照编程人员的编码习惯和参考Python、JQuery等语法对每个模块的语法详细设计.最后设计一个具体的测试用例对解释器进行评价.实验结果表明,该解释器克服了使用Selenium门槛高的缺点,让编写的测试脚本更加简短整洁,测试性能也有明显的提高.     

Determination of ultratrace levels of selenium in fruit and vegetable samples grown and consumed in Portugal

The selenium content in fruit and vegetable samples from two regions in Portugal were analysed using hydride generation atomic fluorescence spectrometry (HG-AFS) and radiochemical nuclear activation analysis (RNAA) – two analytical methods with very low limits of detection. The lower detection limits of HG-AFS, 3 μg kg⁻¹ and 8 μg kg⁻¹ (according to conditions used for digestion), and for RNAA, 10 μg kg⁻¹, meant that it was possible to determine selenium in samples previously analysed using the replicate sample instrumental nuclear activation analysis (RSINAA) with a higher detection limit associated.     

Effect of foliar application of selenium on its uptake and speciation in carrot

Carrot (Daucus carota) shoots were enriched by selenium using foliar application. Solutions of sodium selenite or sodium selenate at 10 and 100 μg Se ml⁻¹, were sprayed on the carrot leaves and the selenium content and uptake rate of selenium were estimated by ICP–MS analysis. Anion and cation exchange HPLC were tailored to and applied for the separation of selenium species in proteolytic extracts of the biological tissues using detection by ICP–MS or ESI–MS/MS. Foliar application of solutions of selenite or selenate at 100 μg Se ml⁻¹ resulted in a selenium concentration of up to 2 μg Se g⁻¹ (dry mass) in the carrot root whereas the selenium concentration in the controls was below the limit of detection at 0.045 μg Se g⁻¹ (dry mass). Selenate-enriched carrot leaves accumulated as much as 80 μg Se g⁻¹ (dry mass), while the selenite-enriched leaves contained approximately 50 μg Se g⁻¹ (dry mass). The speciation analyses showed that inorganic selenium was present in both roots and leaves. The predominant metabolised organic forms of selenium in the roots were selenomethionine and γ-glutamyl-selenomethyl-selenocysteine, regardless of which of the inorganic species were used for foliar application. Only selenomethionine was detected in the carrot leaves. The identity of selenomethionine contained in carrot roots and leaves was successfully confirmed by HPLC–ESI–MS/MS.     

长寿地区大米中硒的有机形态及其生物利用度研究

为了探究典型长寿区大米有机硒的赋存形态与人体硒营养水平的关系,本文分析了江西典型长寿区大米中有机硒、谷蛋白硒、硒代蛋氨酸（Selenomethionine, SeMet）等的组成特征,并运用胃肠体外模拟法对大米硒的生物可利用度及其与各有机硒组分之间的相关关系进行了研究。结果表明,大米中的硒主要以有机形式（78.67 ± 13.52%）赋存,其中,53.73 ± 8.27%的有机硒为谷蛋白硒,且65%以上的谷蛋白硒可酶解消化为SeMet。大米硒的生物可利用度为55.58 ± 10.53%。大米谷蛋白中SeMet比例相对较高且易于被人体吸收利用,这可能与当地居民的健康长寿关系密切。不过,SeMet与大米可利用硒的相关系数仅为0.55。因此,未来有必要对大米中不同硒蛋白的代谢产物（如SeMet）进行研究。     

基于BDD 的自动化测试框架研究

敏捷开发模式的盛行掀起了自动化测试的一轮热潮,测试和开发合作越来越密切。本文研究的自动化测试框 架,将BDD 的敏捷开发理念与软件测试相融合,通过统一的Gherkin 语言定义验收测试标准,帮助业务人员、测试人员和开发 人员形成对需求明确统一的认识,然后通过web driver 测试代码实现可执行的验收测试,以TDD 的方式实现产品代码。该框 架使用Specflow、Selenium 和MsTest 等测试工具,真正实现了自动化测试,大大减少了手工测试的压力,促进开发测试过程中 软件开发涉众之间的沟通,及时得到用户反馈,满足快速发布产品的需求,提升产品质量。     

Diffraction efficiency change in PVA/AA photopolymer films by photosensitive inorganic compound addition

The highest diffraction efficiency (DE) value after illumination and post-curing of photopolymer films were obtained at the SeO₂/Acrylamide (AA) Ratios of AA 3.0 g, SeO₂ 1.0 g and the DE’s were stable values of over 90%. By the addition of SeO₂, the maximum DE at the initial stage of illumination was reached at 300 seconds, which suggests SeO2 slows down the photopolymerization of. DE variation curve for the optimum composition during extendedtime illumination of 9,000 seconds resembles a sine curve due to the combination of the monomer diffusion and the photopolymerization, and the photopolymer film expanded at about 8% after photopolymerization due to monomer migration.     

增效剂对油溶性茶多酚硒的抗氧化增效作用研究

在100℃恒温及黑暗条件下,采用空气自然氧化考察了维生素C、酒石酸、柠檬酸对LTP-Se在蓖麻油中抗氧化性能。结果表明m(增放剂)的添加量为0.01%、0.03%、0.05%时,对油溶性茶多酚硒抗氧化增效效果较好,m(VC)添加量为0.05%,LTP-Se添加浓度为100mg/kg的油样抗氧化生最佳。     

HPLC-ICP-MS法分析测定富硒保健品中的硒形态

确定保健品中硒形态(亚硒酸根、硒酸根),采用水浴振荡提取的前处理方法,液相色谱柱选用IonPac AS11(250 mm×4 mm)分析柱+IonPac AG11(50 mm×4 mm)保护柱,对其进行分离,ICP-MS检测。本文探讨色谱柱、流动相、样品前处理方法的选择,并且在液体、胶囊、鱼油、片状保健品中进行加标回收实验,亚硒酸根、硒酸根的回收率为79.7%-116.4%,精密度(RSD)小于15%。该方法具有灵敏度高、干扰小、样品前处理简单等优点,可以用于保健品中硒形态的筛查和测定。