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Laser-induced breakdown spectroscopy(LIBS) is used to determine the total nitrogen(TN) and total phosphorus(TP) in soil.Quantitative determinations are conducted using the line intensity of the analyte element and element concentration.Calibration models are obtained using ten samples for TN and seven samples for TP.The rest samples are used to validate the results.Strong linear correlations are obtained from the determined TN and TP concentrations.LIBS is a powerful tool for analyzing soil samples to determine nutrient elements by selecting calibration and validation samples with similar matrix composition. 相似文献
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Dr. Yue Wang Fang Zhou Prof. Dr. Qingtao Meng Songhe Zhang Dr. Hongmin Jia Dr. Cuiping Wang Dr. Run Zhang Prof. Dr. Zhiqiang Zhang 《化学:亚洲杂志》2021,16(21):3419-3426
The detection of changes in the reactive oxygen species (ROS)/reactive sulfur species (RSS) couple is important for studying the cellular redox state. Herein, we developed a 1,8-naphthalimide-based fluorescence probe ( NI ) for the reversible detection of bisulfite (HSO3−) and hydrogen peroxide (H2O2) in vitro and in vivo. NI has been designed with a reactive ethylene unit which specifically reacts with HSO3− by a Michael addition reaction mechanism, resulting in the quenching of yellow fluorescence at 580 nm and the appearing of green fluorescence at 510 nm upon excitation at 500 nm and 430 nm, respectively. The addition product ( NI−HSO3 ) could be specifically oxidized to form the original C=C bond of NI , recovering the fluorescence emission and color. The detection limits of NI for HSO3− and NI−HSO3 for H2O2 were calculated to be 2.05 μM and 4.23 μM, respectively. The reversible fluorescence response of NI towards HSO3−/H2O2 couple can be repeated for at least five times. NI is reliable at a broad pH range (pH 3.0–11.5) and features outstanding selectivity, which enabled its practical applications in biological and food samples. Monitoring the reversible and dynamic inter-conversion between HSO3− and H2O2 in vitro and in vivo has been verified by fluorescence imaging in live HeLa cells, adult zebrafish and nude mice. Moreover, NI has been successfully applied to detect of HSO3− levels in food samples. 相似文献
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Dr. Shengfu Tong Cuiping Luo Jiade Li Dr. Zongwei Mei Prof. Mingmei Wu Prof. Anthony P. O'Mullane Prof. Huaiyong Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21095-21099
The practical applications of non-aqueous lithium-oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Reported here is that commonly encountered fatal problems can be efficiently solved by using a carbon- and binder-free electrode of titanium coated with TiO2 nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li2O2 and Li2CO3 during recharging, thereby reducing the overpotential to one that is near the equilibrium potential for Li2O2 formation. The AuNPs promote Li2O2 formation, resulting in a large discharge capacity. The electrode exhibits excellent stability with about 100 % coulombic efficiency during continuous cycling of up to 200 cycles, which is due to the carbon- and binder-free composition. This work reveals a new strategy towards the development of highly efficient oxygen electrode materials for lithium-oxygen batteries. 相似文献
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Fangyuan?Tian Hongji?LiEmail author Mingji?LiEmail author Cuiping?Li Yingjie?Lei Baohe?Yang 《Mikrochimica acta》2017,184(6):1611-1619
The authors describe a voltammetric sensor for simultaneous determination of dopamine (DA), uric acid (UA), L-tyrosine (Tyr), and the diuretic drug hydrochlorothiazide (HCTZ). The assay is based on the use of graphene nanowalls deposited on a tantalum substrate. The nanowalls are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry. The nanowalls are vertically grown on the substrate by direct-current arc plasma jet chemical vapor deposition. The modified electrode is shown to enable simultaneous differential pulse voltammetric determination of DA, UA, Tyr, and HCTZ. The graphene nanowalls display a large specific surface, high conductivity, and a large number of catalytically active sites for oxidation of analytes. Simultaneous detection is performed best at a pH value of 7.0 and at peak potentials of 0.124 V (vs. SCE) for DA, 0.256 V for UA, 0.536 V for Tyr and 0.708 V for HCTZ. The respective detection limits are 0.04 μM, 0.1 μM, 0.6 μM and 0.4 μM. The results show that this graphene wall modified electrode is a promising tool for the design of sensitive, selective, and stable sensors. 相似文献
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Yan Li Anhuai Lu Hongrui Ding Xin Wang Changqiu Wang Cuiping Zeng Yunhua Yan 《Electrochemistry communications》2010,12(7):944-947
An investigation aimed at checking the integration of cathodic pyrrhotite Fenton's reaction with anodic microbial respiration for the enhancement of MFC performance and treatment of a real landfill leachate was carried out. The MFC equipped with a pyrrhotite-coated graphite-cathode generated the maximum power density of 4.2 W/m3 that was 133% higher than graphite-cathode. Concomitantly, electrochemical impedance spectroscopy (EIS) showed that the polarization resistance of pyrrhotite-cathode (92 Ω) was much lower than the graphite-cathode (1057 Ω), indicating that the cathodic overpotential was significantly lowered, probably due to the occurrence of pyrrhotite Fenton's reaction. The in situ generation of Fenton's reagents (Fe2+ and H2O2) at the pyrrhotite-cathode was demonstrated by the cyclic voltammetry measurement. Besides, reactive oxygen species produced from the pyrrhotite Fenton's reaction were detected and demonstrated to be vital to the enhancement of MFC power output. Further, the effectiveness of this system was examined by treating an old-aged landfill leachate. 77% of color and 78% of COD were removed from the original leachate, indicating that the pyrrhotite not only acted as a cost-effective cathodic catalyst for MFCs in power generation, but also extended the practical merits of traditional MFCs towards advanced oxidation of biorefractory pollutants. 相似文献
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“Host” molecules, containing a binding site that is highly specific for an analyte “guest,” are used as sensors to register
analyte binding through a variety of mechanisms such as colorimetric, fluorescent, or electrochemical signals. There is increasing
interest in the host–guest chemistry on the surface of quantum dots (QDs) and in the changes that it produces in the luminescent
properties of QDs. The bulk of this study focuses on those QDs with bound host molecules (crown ether, cyclodextrin, calixarene,
and porphyrin) and the selectivity they display toward metal ions and small organic molecules. 相似文献