羿喹啉及其衍生物的电子结构与缓蚀性能关系的研究

本文在30℃, 1.0mol.dm^-3 HCl溶液中用电化学方法测定了异喹啉及其羟基,羧基衍生物对Fe电极的缓蚀效率。并用HMO和CNDO/2方法计算了这些化合物的量子化学参数, 发现异喹啉及其衍生物分子中氮原子电荷和π净电荷越小, 缓蚀性能越好; 随着这些化合物异喹啉环中吡啶环上原子电荷之和的增大, 缓蚀性能提高; 吡啶环亲核前沿电荷与缓蚀效率有很好的线性关系, 提出了这类缓蚀剂分子可能呈平卧方式吸附于金属电极表面, 从而起缓蚀作用, 预测了五个新分子的缓蚀性能。     

羿喹啉及其衍生物的电子结构与缓蚀性能关系的研究

本文在30℃, 1.0mol.dm^-3 HCl溶液中用电化学方法测定了异喹啉及其羟基,羧基衍生物对Fe电极的缓蚀效率。并用HMO和CNDO/2方法计算了这些化合物的量子化学参数, 发现异喹啉及其衍生物分子中氮原子电荷和π净电荷越小, 缓蚀性能越好; 随着这些化合物异喹啉环中吡啶环上原子电荷之和的增大, 缓蚀性能提高; 吡啶环亲核前沿电荷与缓蚀效率有很好的线性关系, 提出了这类缓蚀剂分子可能呈平卧方式吸附于金属电极表面, 从而起缓蚀作用, 预测了五个新分子的缓蚀性能。     

5-苯基-1H-四氮唑对铜片缓蚀性能的研究

通过金相显微镜和接触角测试研究了5-苯基-1H-四氮唑在硫-乙醇体系中对铜的缓蚀性能。结果显示,缓蚀剂可以在铜片表面形成疏水性保护膜,有效抑制了铜片的腐蚀。电化学测试表明,当缓蚀剂浓度为70 mg/L时缓蚀效率达到87%,对铜电极有明显的缓蚀作用。通过量子化学密度泛函理论研究了缓蚀剂分子结构与缓蚀性能的关系,分析了缓蚀剂分子的活性位点。通过分子动力学模拟研究了缓蚀剂分子在Cu的(111)表面的吸附行为。     

流动条件下两种不同亲水基团咪唑啉型缓蚀剂的缓蚀性能

选择了两种含有不同亲水基团的咪唑啉型缓蚀剂, 即1-胺乙基-2-十一烷基咪唑啉(AEI-11)和1-羟乙基-2-十一烷基咪唑啉(HEI-11), 分别在静态及动态条件下,采用失重法、极化曲线法、电化学阻抗谱法研究了上述缓蚀剂对N80钢在CO2饱和的3%(w)NaCl溶液中的缓蚀性能. 研究结果表明, 无论在静态和动态条件下, HEI-11均表现出更佳的缓蚀性能, 即咪唑啉型缓蚀剂的缓蚀性能与亲水基团的极性成正比; 在流动条件为5 m·s-1时, 缓蚀剂的缓蚀效率显著降低. 为了进一步研究缓蚀剂的缓蚀性能与其结构的关系, 运用量子化学法计算了缓蚀剂的EHOMO(最高占有分子轨道)、ELUMO(最低空分子轨道), 结果表明缓蚀剂的缓蚀效率与EHOMO成正比, 与ELUMO及ELUMO与EHOMO的差值驻E成反比.     

苯并咪唑类缓蚀剂缓蚀性能的理论评价

采用量子化学计算和分子动力学模拟相结合的方法, 对2-巯基苯并咪唑(A)、2-氨基苯并咪唑(B)、2-甲基苯并咪唑(C)和苯并咪唑(D)等四种缓蚀剂抑制HCl对碳钢腐蚀的性能进行理论评价, 并对其缓蚀机理进行分析. 全局活性指数的计算表明, 四种分子中, 2-巯基苯并咪唑分子具有最强的反应活性; 对于其他三种分子, Fukui指数和全电子密度分布指出, 2-氨基苯并咪唑具有两个亲电攻击中心, 可在金属表面形成双中心吸附, 其缓蚀性能应优于2-甲基苯并咪唑和苯并咪唑; 缓蚀剂分子与三层铁原子表面相互作用的分子动力学模拟进一步确认2-甲基苯并咪唑比苯并咪唑在金属表面吸附更稳定. 综合量子化学计算和分子动力学模拟的计算结果, 四种缓蚀剂分子缓蚀效率的顺序应为A>B>C>D, 缓蚀性能的理论评价结论与实验结果相吻合.     

离子液体[Bmim]Cl在H2SO4中对Q235钢的缓蚀实验和理论分析

探究1-丁基-3-甲基-咪唑氯盐([Bmim]Cl)在H_2SO_4介质中对Q235钢的缓蚀性能,解决酸性环境在金属表面造成的腐蚀危害。采用静态缓蚀失重法、电化学法分析了不同浓度[Bmim]Cl对Q235钢的缓蚀性能。Q235钢表面形貌特征以及吸附行为分别采用了扫描电子显微镜(SEM)及吸附等温模型进行了分析。采用理论模拟计算分析了缓蚀剂分子在碳钢表面的缓蚀机理。结果表明,[Bmim]Cl为阴极主导的混合型缓蚀剂,随[Bmim]Cl浓度的增加,缓蚀效果越好,当[Bmim]Cl浓度为0.6 mol·L~(-1)时,缓蚀效率可达91%以上,等温吸附模型证明缓蚀剂分子可自发吸附在金属表面,符合Langmuir等温线。[Bmim]Cl通过化学键与Q235钢表面结合形成了以咪唑杂环为吸附中心、稳定化学吸附的单分子吸附层,且[Bmim]~+平行吸附于表面达到防腐蚀效果。[Bmim]Cl是一种性能优异的防腐蚀剂,能有效预防Q235钢在H_2SO_4介质中的腐蚀。     

三种咪唑类药物缓蚀性能的实验与理论研究

本文采用失重法研究了在5%的H2SO4溶液中甲硝唑(MNZ)、奥美拉唑(OPZ)和酮康唑(KCZ)对钢的缓蚀性能,同时测定了浓度、时间和温度对这类缓蚀剂缓蚀性能的影响。结果表明,在5%的H2SO4溶液中这类缓蚀剂均能有效的抑制钢腐蚀,其中KCZ效果最好,缓蚀效率可达80%以上。并采用密度泛函(DFT)理论计算方法对三种缓蚀剂分子结构与缓蚀性能之间的关系进行了探讨,结果表明,缓蚀效率与分子的最高占据轨道的能量EHOMO、最低空轨道与最高占据轨道的能量差ΔE(ELUMO-EHOMO)有较好的相关性,理论评价结果与实验结果相吻合。     

一种酸洗缓蚀剂的合成及缓蚀性能研究

咪唑啉类化合物能够提供π电子和杂原子使其吸附在金属表面,从而达到缓蚀作用。而分子中不饱和键的引入有助于缓蚀效率的提高。用苯甲醛、三乙烯四胺及丙烯酸为原料合成了咪唑啉型化合物SEI,进行了IR表征,     

MDOPD在Q235钢表面的吸附特性研究

应用静态失重法、动电位扫描极化曲线、交流阻抗和原子力显微镜等方法研究含咪唑杂环的双季铵盐化合物MDOPD在模拟油田水中对Q235钢的缓蚀性能及其缓蚀吸附机理.结果表明,双季铵盐化合物MDOPD在模拟油田水介质中对Q235钢具有非常显著的缓蚀效果;其缓蚀吸附膜随吸附时间的延长而更加完整和致密;MDOPD的较强缓蚀性能与其分子中含有多个活性吸附中心以及在金属表面的平卧吸附方式有关.     

氯化2,3,5-三苯基-2H-四唑及2,4,6-三(2-吡啶基)-s-三嗪在1mol/L HCl中对Q235碳钢的缓蚀作用及机理的研究(Ⅱ)

通过x射线光电子能谱(XPS)、椭圆偏振原位测试考察了氯化2,3,5-三苯基-2H-四唑(TTC),2,4,6-三(2-吡啶基)-s-三嗪(TPT)分子在1 mol/L HCI中对碳钢表面的缓蚀作用,并从微观上对二者的缓蚀机理进行探讨.XPS测试结果显示,由C,N元素的1s特征峰产生的化学位移及其积分峰面积表明TTC,TPT分子在金属表面产生了有效抑制腐蚀的保护层;由椭圆偏振原位测试并结合动电位极化曲线测试,考察了TTC,TPT分子对金属表面腐蚀反应的抑制程度,并得到了相位差等参量,结果表明二者在金属表面形成了具有缓蚀作用的覆盖层.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.