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Located along the southern part of the West Qinling orogenic belt, the Yangshan gold deposit is one of the largest in China. The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor native gold amounts in stibnite‐gold quartz veins. Pyrite and arsenopyrite are the major Au‐bearing minerals. Hydrothermal muscovite from gold‐bearing quartz veins was dated using the in situ Rb‐Sr method to determine the formation age of the Yangshan gold deposit. The Rb‐Sr isochron date of the muscovite yielded 210.1 ± 5.6 Ma (MSWD = 1.2). This date is near the lower end of the period of the mineralized granitic dykes (210.49–213.10 Ma). Two stages of gold enriching process are recognized in the gold‐bearing pyrite: the first is incorporated with the Co, Cu, As, Ni enrichment; and the second is accompanied by Bi, Co, Ni, Pb, Cu, Sb concentration. The in‐situ sulfur isotopic values of pyrites show a restricted Δ34s range of –1.43 ‰ to 2.86 ‰ with a mean value of 0.43 ‰. Trace‐element mapping and in‐situ sulfur isotopic analysis of pyrite suggest that the sulfur deposits are likely derived from a magmatic source and likely assimilated by sulfur from the sedimentary bedrock. Thus, magmatism plays a critical role in the formation of the Yangshan gold deposit. [ABSTRACT FROM AUTHOR]

Biochar loaded with metal ions has been widely used to activate persulfate to degrade organic pollutants. However, the preparation conditions of catalysts are always controversial. In this study, the co‐heating conditions of soybean straw with high carbon and low nitrogen and nano‐iron oxide were systematically discussed by response surface method, and an efficient catalyst (Fe@BC) was obtained. Fe@BC can effectively activate sodium persulfate (PS) and degrade three synthetic azo dyes (Methyl orange (MO), Amino black 10B (AB10B), and Orange II) and rhodamine B (RhB). Under the optimum conditions, the removal rate of total organic carbon of these four dyes reached 41.1%–89.8% and the final degradation rate could reach 100%. The physicochemical properties of Fe@BC were studied by SEM, BET, XRD, XPS and TGA. The results revealed that the specific surface area of Fe@BC was 195.6m2/g. Further, reducing iron oxide by C generated C0.09Fe1.91 and zero‐valent iron. Free radical scavenging experiments and electron paramagnetic resonance (EPR) measurements showed that the main reactive oxide species (ROS) in the Fe@BC/PS system were hydroxyl radicals (•OH) and singlet oxygen (1O2). Finally, Several Fe@BC modification systems were explored, the optimum pH of Fe@BC/PS system was analyzed, and the effects of Fe@BC and PS dosage on degradation performance were also studied. This study provides a scientific basis for the production of efficient catalysts and biochar energy, and an effective treatment scheme for printing and dyeing wastewater. [ABSTRACT FROM AUTHOR]

Poly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate) (PTMA) is a typical organic battery material containing nitrogen and oxygen radicals. The grafting of PTMA onto graphene oxide to obtain composite cathode material poly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate)‐Graphene Oxide (PTMA‐GO) via click chemistry is reported. The method of preparing PTMA‐GO is completed at room temperature, which can retain the oxygen‐containing functional groups on the surface of graphene oxide, and the process is simple and easy to conduct. The composite materials are characterized by infrared, X‐ray diffraction, thermogravimetry, and electron paramagnetic resonance. The cathode material is assembled in a button battery to measure its cyclic voltammogram, electrochemical impedance spectroscopy, and charge and discharge capacity cycles. It is found that the PTMA‐GO electrode is twice as conductive as the PTMA electrode alone. The specific capacity of the PTMA‐GO electrode is nearly 2.3 times higher than that of the PTMA electrode after 300 charge–discharge cycles. This represents an important reference value for the development of organic batteries, especially for the research of nitroxide radical polymer electrode materials. [ABSTRACT FROM AUTHOR]

Fast immunoassay-based screening methods are unavailable for most small-molecule pesticides because of a lack of immunogenicity and the difficulty in obtaining antibodies by animal immunization. Aptamers are single-stranded DNA molecules selected through an in vitro process, which can bind to any target including nonimmunogenic small molecules with high affinity and specificity. Although various aptamer-based sensing methods have been developed for antibiotics, microorganisms, heavy metal ions, and biotoxins, there are few reports on aptamer-based methods for quick detection of organophosphorous pesticides. The gold (Au) nanoparticle (AuNP) colorimetric assay is a widely utilized rapid detection method because of properties such as easy operation and visualized results. In the present study, organophosphorous pesticide aptamers were adsorbed on the surface of AuNPs to stabilize the AuNP solution against high concentrations of salt to prevent AuNP aggregation. After the addition of targets, the aptamers binding to the targets are detached from the AuNPs, resulting in aggregation of AuNPs and a color change from red to purple-blue. The proposed method can detect 6 organophosphorous pesticides with good recoveries from 72% to 135% in environmental river water samples. The present study provides a new way for simple, rapid, and multiplex detection of organophosphorous pesticides. Environ Toxicol Chem 2015;34:2244-2249. © 2015 SETAC [ABSTRACT FROM AUTHOR]