120 research outputs found

    Determination of Catechol by Cetyltrimethylammonium Bromide Functionalized Graphene Modified Electrode

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    A simple and sensitive electrochemical sensor was prepared by using electrodeposition of the cetyltrimethylammonium Bromide (CTMAB ) functionalized Graphene (GR) on the glassy carbon electrode (GCE) to determine Catechol (CC) in water. The performance of the CTMAB functionalized GR sensor was studied and the analysis conditions of the CC were optimized. The experimental results showed that, compared with bare GCE, the redox peak current of CC on the modified electrode was obviously enhanced. Under the optimized conditions, the oxidation and reduction peak current all showed a good linear relationship with the concentration of CC from 5μmol/L to 1000 μmol/L. The detection limit of oxidation peak is 2.92 μmol/L, and that of reduction peak is 2.44 μmol/L. The recovery was founded to be in the range of 92.70 %~101.80 %. Moreover, the sensor could be used for the determination of CC in real samples with satisfactory results. And the mechanism of the sensitization of CC detected by CTMAB-GR modified GCE was discussed preliminarily

    Determination of Catechol by Cetyltrimethylammonium Bromide Functionalized Graphene Modified Electrode

    Get PDF
    A simple and sensitive electrochemical sensor was prepared by using electrodeposition of the cetyltrimethylammonium Bromide (CTMAB ) functionalized Graphene (GR) on the glassy carbon electrode (GCE) to determine Catechol (CC) in water. The performance of the CTMAB functionalized GR sensor was studied and the analysis conditions of the CC were optimized. The experimental results showed that, compared with bare GCE, the redox peak current of CC on the modified electrode was obviously enhanced. Under the optimized conditions, the oxidation and reduction peak current all showed a good linear relationship with the concentration of CC from 5μmol/L to 1000 μmol/L. The detection limit of oxidation peak is 2.92 μmol/L, and that of reduction peak is 2.44 μmol/L. The recovery was founded to be in the range of 92.70 %~101.80 %. Moreover, the sensor could be used for the determination of CC in real samples with satisfactory results. And the mechanism of the sensitization of CC detected by CTMAB-GR modified GCE was discussed preliminarily

    Determination of Catechol by Cetyltrimethylammonium Bromide Functionalized Graphene Modified Electrode

    Get PDF
    A simple and sensitive electrochemical sensor was prepared by using electrodeposition of the cetyltrimethylammonium Bromide (CTMAB ) functionalized Graphene (GR) on the glassy carbon electrode (GCE) to determine Catechol (CC) in water. The performance of the CTMAB functionalized GR sensor was studied and the analysis conditions of the CC were optimized. The experimental results showed that, compared with bare GCE, the redox peak current of CC on the modified electrode was obviously enhanced. Under the optimized conditions, the oxidation and reduction peak current all showed a good linear relationship with the concentration of CC from 5μmol/L to 1000 μmol/L. The detection limit of oxidation peak is 2.92 μmol/L, and that of reduction peak is 2.44 μmol/L. The recovery was founded to be in the range of 92.70 %~101.80 %. Moreover, the sensor could be used for the determination of CC in real samples with satisfactory results. And the mechanism of the sensitization of CC detected by CTMAB-GR modified GCE was discussed preliminarily

    Microbial-induced remediation of Zn2+ pollution based on the capture and utilization of carbon dioxide

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    Background: Microbial-induced remediation of Zn2+ pollution based on the capture and utilization of carbon dioxide was investigated. In this study, carbon dioxide was absorbed and transformed into carbonate ions under the enzymatic action of Paenibacillus mucilaginosus , which was being utilized to mineralize Zn2+. Results: The compositional and morphological properties of the precipitations were studied using Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The thermal properties of the precipitates were investigated by thermogravimetric-differential scanning calorimetry (TG-DSC). The FTIR results confirmed that the functional groups of the precipitates were CO3 2 12 and OH 12. The XRD and EDS patterns showed that basic zinc carbonate could be obtained successfully by Microbial-induced remediation. The SEM micrographs demonstrated that the precipitates were in the nanometer range with sizes of 100\u2013200 nm and were sphere-like in shape. Conclusions: The TG-DSC results showed that weight loss of the precipitates occurred around 253\ub0C. The FTIR and TG-DSC results were in accord with the XRD and EDS results and proved again that the precipitates were basic zinc carbonate. This work thus demonstrates a new method for processing Zn2+ pollution based on the utilization of carbon dioxide

    Determination of Catechol by Cetyltrimethylammonium Bromide Functionalized Graphene Modified Electrode

    Get PDF
    A simple and sensitive electrochemical sensor was prepared by using electrodeposition of the cetyltrimethylammonium Bromide (CTMAB ) functionalized Graphene (GR) on the glassy carbon electrode (GCE) to determine Catechol (CC) in water. The performance of the CTMAB functionalized GR sensor was studied and the analysis conditions of the CC were optimized. The experimental results showed that, compared with bare GCE, the redox peak current of CC on the modified electrode was obviously enhanced. Under the optimized conditions, the oxidation and reduction peak current all showed a good linear relationship with the concentration of CC from 5μmol/L to 1000 μmol/L. The detection limit of oxidation peak is 2.92 μmol/L, and that of reduction peak is 2.44 μmol/L. The recovery was founded to be in the range of 92.70 %~101.80 %. Moreover, the sensor could be used for the determination of CC in real samples with satisfactory results. And the mechanism of the sensitization of CC detected by CTMAB-GR modified GCE was discussed preliminarily

    NtMYB4 and NtCHS1 Are Critical Factors in the Regulation of Flavonoid Biosynthesis and Are Involved in Salinity Responsiveness

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    High levels of salinity induce serious oxidative damage in plants. Flavonoids, as antioxidants, have important roles in reactive oxygen species (ROS) scavenging. In the present study, the tobacco R2R3 MYB type repressor, NtMYB4, was isolated and characterized. The expression of NtMYB4 was suppressed by salinity. Overexpression of NtMYB4 reduced the salt tolerance in transgenic tobacco plants. NtMYB4 repressed the promoter activity of NtCHS1 and negatively regulated its expression. Rutin accumulation was significantly decreased in NtMYB4 overexpressing transgenic plants and NtCHS1 RNAi silenced transgenic plants. Moreover, high H2O2 and O2− contents were detected in both types of rutin-reduced transgenic plants under high salt stress. In addition, exogenous rutin supplementation effectively scavenged ROS (H2O2 and O2−) and improved the salt tolerance of the rutin-reduced transgenic plants. In contrast, NtCHS1 overexpressing plants had increased rutin accumulation, lower H2O2 and O2− contents, and higher tolerance to salinity. These results suggested that tobacco NtMYB4 acts as a salinity response repressor and negatively regulates NtCHS1 expression, which results in the reduced flavonoid accumulation and weakened ROS-scavenging ability under salt stress

    Attribution of extreme precipitation in the lower reaches of the Yangtze River during May 2016

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    May 2016 was the third wettest May on record since 1961 over central eastern China based on station observations, with total monthly rainfall 40% more than the climatological mean for 1961–2013. Accompanying disasters such as waterlogging, landslides and debris flow struck part of the lower reaches of the Yangtze River. Causal influence of anthropogenic forcings on this event is investigated using the newly updated Met Office Hadley Centre system for attribution of extreme weather and climate events. Results indicate that there is a significant increase in May 2016 rainfall in model simulations relative to the climatological period, but this increase is largely attributable to natural variability. El Ni ̃no years have been found to be correlatedwith extreme rainfall in the Yangtze River region in previous studies—the strong El Ni ̃no of 2015–2016 may account for the extreme precipitation event in 2016. However, on smaller spatial scales we find that anthropogenic forcing has likely played a role in increasing the risk of extreme rainfall to the north of the Yangtze and decreasing it to the south

    Comparing Monofractal and Multifractal Analysis of Corrosion Damage Evolution in Reinforcing Bars

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    Based on fractal theory and damage mechanics, the aim of this paper is to describe the monofractal and multifractal characteristics of corrosion morphology and develop a new approach to characterize the nonuniform corrosion degree of reinforcing bars. The relationship between fractal parameters and tensile strength of reinforcing bars are discussed. The results showed that corrosion mass loss ratio of a bar cannot accurately reflect the damage degree of the bar. The corrosion morphology of reinforcing bars exhibits both monofractal and multifractal features. The fractal dimension and the tensile strength of corroded steel bars exhibit a power function relationship, while the width of multifractal spectrum and tensile strength of corroded steel bars exhibit a linear relationship. By comparison, using width of multifractal spectrum as multifractal damage variable not only reflects the distribution of corrosion damage in reinforcing bars, but also reveals the influence of nonuniform corrosion on the mechanical properties of reinforcing bars. The present research provides a new approach for the establishment of corrosion damage constitutive models of reinforcing bars
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