The binary system 53 Cam

The orbital elements of the spectroscopic binary 53 Cam were revised using 136 radial velocity measurements. The positions in the vicinity of the periastron predicted for the secondary under the assumption of the spectroscopic orbital elements do not agree with those found by speckle interferometric observations. Nevertheless, we try to estimate the mass of the secondary and the dimensions of the binary system.     

Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy （EIS）. Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.     

基于SERS技术的果蔬表皮农药残留快速检测方法研究

果蔬表皮农药残留关乎食品安全问题。本文以苹果为研究对象,应用表面增强拉曼光谱(SERS)技术,结合高灵敏度、便携的纳米检测棒,检测果蔬中常用农药倍硫磷和多菌灵,研究农药残留衰减规律,并对比研究不同方法对农药残留的去除效果。研究表明,基于GMA-EDMA多孔材料和金纳米颗粒制备的纳米检测棒,对苹果表皮残留的倍硫磷和多菌灵的最低检测浓度分别达0.10和0.05 mg/L,在低浓度范围内特征峰强度与浓度成良好的线性关系。苹果表皮两种农药残留量随时间成e指数衰减,衰减为e-1的时间常数分别约为1~2 d和4~5 d。不同清洗剂(清水、盐水、小苏打水、果蔬洗涤剂)对农药残留的清洗效果不同,淡盐水可提高农药残留清洗效率,清水清洗需要延长清洗时间才能达到相同效果。研究结果表明,纳米检测棒能有效提高果蔬农药残留的检测灵敏度和检测效率,结合便携式拉曼系统,可实现果蔬农药与淡盐水残留的快速、现场检测。     

黔西南架底金矿床流体包裹体研究

架底金矿是近年来在黔西南新发现的主要赋存于玄武岩中的大型微细粒浸染型金矿床。为查明其成矿流体特征,探讨流体成矿机制,针对矿床不同成矿阶段采取流体包裹体样品开展工作。根据野外观察和室内分析,架底金矿热液成矿期可分为3个阶段:黄铁矿阶段、烟灰色石英阶段和硫化物阶段,其中烟灰色石英阶段为主要成矿阶段。流体包裹体以NaCl-H₂O和CO₂-NaCl-H₂O型为主,黄铁矿阶段富CO₂包裹体,均一温度（T_h）为211~231℃,盐度（wt）为2.10~7.60（% NaCl equiv）;烟灰色石英阶段见大量NaCl-H₂O和CO₂-NaCl-H₂O型包裹体,均一温度（T_h）为182~218℃,盐度（wt）为1.40~5.90（% NaCl equiv）;硫化物阶段包裹体均一温度（T_h）普遍小于183℃,盐度（wt）为0.90~5.30（% NaCl equiv）。激光拉曼光谱分析显示包裹体中含CO₂、CH₄、N₂、SO₂等气相组分,随着成矿流体均一温度、盐度和密度的不断下降,包裹体中气相组分种类也趋于简单。通过计算成矿流体的ρ、P、pH、Eh和f_O2等物理化学参数,表明成矿环境具有中低温、低盐度、低密度、近中性、相对还原及低氧逸度的特征。流体包裹体组合变化表明成矿作用发生在流体CO₂含量不断降低的过程,主成矿阶段流体混合和区域伸展构造引起流体沸腾作用强烈,大量金属成分（黄铁矿、自然金等）快速沉淀形成金矿体。      

Application of Laser‐Induced Breakdown Spectroscopy and Hyperspectral Images for Direct Evaluation of Chemical Elemental Profiles of Coprolites

This study demonstrates the application of laser‐induced breakdown spectroscopy (LIBS) and hyperspectral imaging to the investigation of coprolite and fossil samples. Solid samples from the Permian (seven coprolites and one fossil), Cretaceous (one coprolite) and Oligo‐Miocene (two coprolites) periods were directly analysed, and emission spectra from 186 to 1042 nm were obtained in several areas covering coprolite/fossil and rock material. Initial exploratory analyses were performed using principal component analysis with the data set normalised by the norm (Euclidean norm = 1). After identification and selection of emission lines of eleven elements (Al, Ca, Cr, Fe, K, Mg, Mn, Na, Ni, P and Si), the signals were normalised again by the relative intensity of the selected element. Phosphorus was identified mainly in the coprolites, while K and Na were primarily found in the rock material. In several cases, there was a positive correlation between Ca and P. A sample from the Oligo‐Miocene series was also analysed using inductively coupled plasma‐optical emission spectrometry (ICP‐OES) (rock and coprolites were analysed separately). Based on the quantitative results from ICP‐OES, it was confirmed that the tendency was the same as that observed with the results obtained from LIBS directly in the solid sample.     

新建人工深水湖泊沉积物上覆水和孔隙水中溶解性有机质的光谱特征

为了揭示湖库内源性污染物的分布、来源、组成及垂向分布特征,以新建人工深水湖泊龙景湖为研究对象,采用紫外-可见光谱和三维荧光光谱技术,研究了该湖泊以成湖前用途划分的3个特征区域(原河道底部、新淹没区底部和新淹没区边坡)的沉积物上覆水和孔隙水中的溶解性有机质(DOM)的光谱特征.结果表明,孔隙水中的DOM芳香性和腐殖化程度高于上覆水;孔隙水中疏水组分含量大于上覆水,且水体中可能存在内源孔隙水释放的低分子量DOM.龙景湖上覆水和孔隙水中的DOM主要源于水体自身的微生物,自生源特征明显,且可能存在新近释放到水体的有机质.龙景湖沉积物上覆水和孔隙水中的DOM以类腐殖酸和类蛋白质为主,且随着深度增加,类腐殖酸峰强度增强,与龙景湖的建湖背景有明显联系.     

Distribution of Fe among octahedral sites and its effect on the crystal structure of pumpellyite

Two pumpellyites with the general formula W ₈ X ₄ Y ₈ Z ₁₂O_56-n (OH) _n were studied using ⁵⁷Fe Mössbauer spectroscopic and X-ray Rietveld methods to investigate the relationship between the crystal chemical behavior of iron and structural change. The samples are ferrian pumpellyite-(Al) collected from Mitsu and Kouragahana, Shimane Peninsula, Japan. Rietveld refinements gave Fe(X):Fe(Y) ratios (%) of 41.5(4):58.5(4) for the Mitsu pumpellyite and 46(1):54(1) for the Kouragahana pumpellyite, where Fe(X) and Fe(Y) represent Fe content at the X and Y sites, respectively. The Mössbauer spectra consisted of two Fe²⁺ and two Fe³⁺ doublets for the Mitsu pumpellyite, and one Fe²⁺ and two Fe³⁺ doublets for the Kouragahana pumpellyite. In terms of the area ratios of the Mössbauer doublets and the Fe(X):Fe(Y) ratios determined by the Rietveld refinements, Fe²⁺(X):Fe³⁺(X):Fe³⁺(Y) ratios are determined to be 22:14:64 for the Mitsu pumpellyite and 27:8:65 for the Kouragahana pumpellyite. By applying the Fe²⁺:Fe³⁺-ratio determined by the Mössbauer analysis and the site occupancies of Fe at the X and Y sites given by the Rietveld method together with chemical analysis, the resulting formula of the Mitsu and Kouragahana pumpellyites are established as Ca₈(Fe _0.88 ²⁺ Mg_0.68Fe _0.77 ³⁺ Al_1.66)_Σ3.99(Al_5.67Fe _2.34 ³⁺ )_Σ8.01Si₁₂O_42.41(OH)_13.59 and Ca₈(Mg_1.24Fe _0.65 ²⁺ Fe _0.46 ³⁺ Al_1.66)_Σ4.01(Al_6.71Fe _1.29 ³⁺ )_Σ8.00Si₁₂O_42.14(OH)_13.86, respectively. Mean Y–O distances and volumes of the YO₆ octahedra increase with increasing mean ionic radii, i.e., the Fe³⁺→Al substitution at the Y site. However, change of the sizes of XO₆ octahedra against the mean ionic radii at the X site is not distinct, and tends to depend on the volume change of the YO₆ octahedra. Thus, the geometrical change of the YO₆ octahedra with Fe³⁺→Al substitution at the Y site is essential for the structural changes of pumpellyite. The expansion of the YO₆ octahedra by the ionic substitution of Fe³⁺ for Al causes gradual change of the octahedra to more symmetrical and regular forms.     

天然海水中微生物膜对碳钢腐蚀行为的影响

通过对比碳钢在天然海水和灭菌海水中的腐蚀行为,研究海洋微生物对碳钢材料的腐蚀行为的影响.结果表明,海洋微生物可在碳钢表面形成微生物膜,其对碳钢腐蚀速率的影响及作用机理与微生物的种类密切相关.在腐蚀初期,海洋微生物膜对碳钢的腐蚀起到了抑制作用,主要由多种好氧微生物协同作用的结果;在腐蚀后期,随着海洋微生物膜增厚导致厌氧腐蚀的出现从而加速腐蚀,主要是硫酸盐还原菌等厌氧微生物的作用.     

山东省周村水库季节演替中沉积物上覆水溶解性有机物的紫外-可见与三维荧光光学特征

运用三维荧光光谱（EEMs）技术结合平行因子分析法（PARAFAC）以及紫外-可见光谱技术（UV-vis）,对周村水库季节演替过程中沉积物上覆水溶解性有机物（DOM）的紫外-可见以及三维荧光光谱特征进行分析.结果表明：周村水库上覆水的总氮、溶解性总氮、总有机碳和溶解性有机碳的季节性差异显著,并且冬季总氮浓度最高、夏秋季总有机碳浓度较高;夏秋季上覆水DOM的吸收系数a₂₅₄和a₃₅₅均高于冬春季,与有机物的分布相一致;4个季节上覆水DOM的E3/E4均大于3.5,说明DOM以富里酸为主,E2/E3（富里酸占DOM的比例）在夏秋季低于冬春季,而且各季节S_R均大于1,表明DOM主要为生物源;三维荧光通过PARAFAC解析出3种组分：类腐殖质（C1）、可见区富里酸（C2）和类蛋白（C3）;对3个组分进行相关性分析,结果显示C1、C2、C3之间具有显著的相关性;DOM的总荧光强度以及各组分的荧光强度均呈现出夏秋季高、冬春季低的特征,且各季节间差异显著;周村水库4个季节的DOM生物源指数（BIX）在0.8~1.0之间,表明水库DOM具有较强的自生源特征,与腐殖程度指标（HIX）的结果相吻合;主成分分析显示周村水库上覆水DOM的光谱特征差异明显,夏秋季的DOM光谱特征相近、冬春季的水体DOM特征相似;并且组分C1、C2、C3与DOM特征参数（a₂₅₄、SUVA₂₈₀、HIX、FI、BIX）以及溶解性有机碳呈显著相关.各荧光组分与水质参数（溶解性总氮和溶解性有机碳）的多元线性回归呈现很好的拟合,通过建立回归方程可以为以后研究周村水库水体四季的DOM光谱特征,分析水库水体的有机物污染特征,并为水库水质管理提供技术支持.