低合金钢实海腐蚀电化学阻抗谱研究

采用交流阻抗,结合线性极化,研究低合金钢实海全浸初期电化学阻抗谱行为。结果表明,低合金钢实海腐蚀最初1周是腐蚀最剧烈阶段;低合金钢实海腐蚀分为2个阶段,浸泡的第1周为第1阶段,阻抗值迅速减小,采用等效电路Rs（Cdl,Rt）拟合;浸泡1周之后,阻抗值变化缓慢,且呈现波动趋势,采用等效电路Rs（Cf（Rf（Cdl,Rt）））拟合。     

不同腐蚀体系中低合金钢锈层的拉曼光谱研究

利用激光拉曼光谱法研究了舰船用镍铬系低合金钢在天然海水以及分别添加双氧水、高氯酸钾和过硫酸钠的NaCl（3.5％）溶液等4种体系中浸泡后腐蚀锈层的物相组成。结果表明：在含双氧水体系和天然海水体系中,钢样的内外锈层物相主要是α-Fe2O3、γ-FeOOH和Fe3O4。高氯酸钾和过硫酸钠腐蚀体系,其腐蚀锈层的外锈层除了含有α-Fe2O3和γ-FeOOH外还出现了γ-Fe2O3,内锈层只含有α-Fe2O3和γ-FeOOH,未发现Fe3O4。说明镍铬系低合金钢在含双氧水体系和天然海水体系中的腐蚀锈层物相组成差异最小。     

三维荧光指纹技术用于城市湖泊的有机污染监测

有机物的荧光特性被广泛用来解析其在水体中的来源与分布。荧光光谱技术具有灵敏度高、选择性好、且不破坏样品结构的优点,非常适合用来研究有机物的化学和物理性质。运用三维荧光指纹技术对N市某城市湖泊的有机污染类型和污染程度进行了监测。实验结果表明,三维荧光指纹技术能有效揭示城市湖泊中有机物的动态变化。从七月份到十二月份,N市某城市湖泊的主要有机污染类型为内源污染;其中七月份到九月份还兼有外源污染,而十月份到十二月份基本没有外源污染。实验期间,此城市湖泊水体中C lass III（类蛋白）荧光峰的荧光强度在416.10~298.76之间,C lass I（类腐殖酸）荧光峰的荧光强度在128.90~123.19之间,此城市湖泊的内源污染远大于外源污染。     

水中痕量重金属激光诱导击穿光谱高灵敏检测

采用旋转电极,用电沉积的方法把天然水中痕量的有害重金属离子富集到一个高纯(纯度为99.999%)铝棒表面,然后利用激光诱导击穿光谱对其进行定量分析。采用旋转电极能够较好地排除电解水所产生的气泡对重金属离子电沉积过程的干扰。实验研究了铅和镉两种元素,在富集电压为7.5V,富集时间为20min的条件下制定了两个元素的校正曲线并得出其检出限为500ng/L(Pb)和830ng/L(Cd)。该方法为水环境重金属污染监测提供了一种新的分析技术,它具有灵敏度高和可以多元素同时分析两个突出的优点。     

利用三维荧光技术分析太湖水体溶解性有机质的分布特征及来源

利用三维荧光光谱法研究了太湖125个样点表层(0.5m)和底层(1.5m)水体溶解性有机质(DOM)的组成和分布特征,并对不同湖区DOM的来源进行了分析.结果表明,太湖大部分湖区水体DOM以类蛋白物质为主,其中,竺山湾DOM中的腐殖质和类蛋白物质含量均较其它湖区高.太湖水体DOM的分布存在区域差异性,即:竺山湾湖区西部湖区梅梁湾湖心区贡湖湾南部湖区.分析认为,太湖DOM的来源具有陆源输入与内源微生物降解的双重特征,但竺山湾和西部湖区以陆源输入为主,而梅梁湾、贡湖、南部湖区及湖心区以内源微生物降解为主.分析各类荧光峰强度与水质参数的相关性发现,太湖水体DOM4类荧光峰之间呈显著正相关关系,DOM的4类荧光峰均与总氮(TN)、总磷(TP)、硝酸根离子(NO3-)、铵根离子(NH4+)呈显著正相关关系(p0.01),DOM的各类荧光峰强度和溶解氧呈显著负相关(p0.01),这可能是由于水体DOM含量升高后,微生物比较活跃,消耗大量的溶解氧所致;DOM的各类荧光峰强度和溶解性有机碳(DOC)之间的相关性不显著,可能与不同湖区样品中一些非荧光物质在DOM中的比例不同有关.     

Evolution of humic substances in polymerization of polyphenol and amino acid based on non-destructive characterization

• Humification evolution was identified with non-destructive characterization method. • Humification process from precursors to fulvic and humic acid was confirmed. • MnO₂ alone had limited oxidation ability to form HA. • MnO₂ played a key role as a catalyst to transform FA to HA in the presence of O₂. • MnO₂ could affect the structure of the humification products. Abiotic humification is important in the formation and evolution of organic matter in soil and compost maturing processes. However, the roles of metal oxides in abiotic humification reactions under micro-aerobic remain ambiguous. The aim of this study was to use non-destructive measurement methods to investigate the role of MnO₂ in the evolution of humic substances (HSs) during oxidative polymerization of polyphenol-amino acid. Our results suggested a synergistic effect between MnO₂ and O₂ in promoting the polymerization reaction and identified that MnO₂ alone had a limited ability in accelerating the transformation of fulvic acid (FA) to humic acid (HA), whereas O₂ was the key factor in the process. Two-dimensional correlation spectroscopy (2D-COS) showed that the evolution in the UV-vis spectra followed the order of 475–525 nm>300–400 nm>240–280 nm in the humification process, indicating the formation of simple organic matter followed by FA and then HA. ¹³C nuclear magnetic resonance (¹³C NMR) analysis revealed that the products under both air and N₂ conditions in the presence of MnO₂ had greater amounts of aromatic-C than in the absence of MnO₂, demonstrating that MnO₂ affected the structure of the humification products. The results of this study provided new insights into the theory of abiotic humification.     

Concentration effect of trace metals in Jordanian patients of urinary calculi

Due to the increase in the number of urinary calculi disease cases in Jordan, stone samples were collected from patients from various Jordanian hospitals (Princes Basma (PBH), King Abdullah University (KAUH), Al-Basheer (ABH) and Al-Mafraq (AMH)). This study concentrates on the effect of trace metals in patients of urinary calculi. Trace metals were detected in 110 urinary calculi samples using X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS) techniques. Of the calculi examined, 21 were pure calcium oxalate (CaOax), 29 were mixed calcium oxalate/uric acid, 23 were mixed calcium oxalate/phosphate (apatite), 25 were phosphate calculi (apatite/struvite), five were mixed calcium oxalate monohydrate/struvite, four were urate calculi (mixed ammonium acid urate/sodium acid urate) and three were pure cystine calculi. The concentration measurement of Ca and other trace metals levels has been found useful in understanding the mechanism of stone formation and in evaluating pathological factors. It has been found that Ca is the main constituent of the urinary calculi, especially those stones composed of calcium oxalate and calcium phosphate. The concentration of most of the trace metals that were analyzed was (Ca = 48.18, Na = 1.56, K = 0.9, Mg = 3.08, Fe = 1.17, Al = 0.49, Zn = 0.7, Cu = 0.19, Mn = 0.029, P = 10.35, S = 1.88, Sr = 0.306, Mo = 0.2, Cr = 0.146, Co = 0.05, Ni = 0.014)%. In conclusion, metals concentration in Jordanian patient’s urinary calculi samples was higher than its equivalents of other patients’. It has been noted that there is no concentration of toxic trace elements (like Li, V, Pb, Cd, and As). Some heavy metals, however, were detected Mo, Cr, Co and Ni as traces. P and S ions are present in few calculi stones as traces.     

基于光谱技术的土壤多参数快速检测进展与展望

传统的土壤采样和实验室分析方法往往工作量大、前处理复杂、测定周期长、时效差、费用高,因此,迫切需要寻找快速、准确的土壤多参数检测方法,以实现多尺度土壤属性数据的快速获取与更新。系统梳理了便携式X射线荧光光谱(PXRF)、可见光-近红外反射光谱(Vis-NIR)、激光诱导击穿光谱(LIBS)和电弧发射光谱(AES)等光谱技术的原理、特点以及在土壤多参数快速检测中的应用及其研究进展。提出,未来在提高现有土壤多参数光谱检测精度和适用性的基础上,应结合ICP-MS等传统实验室方法,综合应用多种光谱技术以及化学计量学、现代信息技术和空间分析技术等,实现区域多种土壤属性的快速获取与实时监测,以满足我国当前土壤多参数、高精度快速检测及土壤质量精细化管理的需要。     

Interaction of diuron to human serum albumin: Insights from spectroscopic and molecular docking studies

This investigation was undertaken to determine the interaction of diuron with human serum albumin (HSA) was studied by monitoring the spectral behavior of diuron-HSA system. The fluorescence of HSA at 340 nm excited at 230 nm was obviously quenched by diuron due to dynamic collision and the quenching constant was of the order of 10⁴ L mol^?1 at 310 K. However, no fluorescence quenching was observed when excited at 280 nm. Thermodynamic investigations revealed that the combination between diuron and HSA was entropy driven by predominantly hydrophobic interactions. The binding of diuron induced the drastic reduction in α-helix conformation and the significant enhancement in β-turn conformation of HSA. In addition, both sites marker competition study and molecular modeling simulation evidenced the binding of diuron to HSA primarily took place in subdomain IIIA (Sudlow's site II).     

非分散红外仪测定废水中石油类物质的探讨

探讨了用油份分析仪测定油含量时,对仪器原理的了解,遮光板的作用作用和不同萃取剂对仪器光学零点的影响。指出仪器在调整过程中出现的不正常现象与仪器的性能有关。在测定样品时,就采取正确的前处理方法,以减小测定误差。并对如何做好标样考核进行了初步讨论。