| 1. |
- Huang, Ruihua, et al.
(författare)
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Star-shaped porous nitrogen-doped metal-organic framework carbon as an electrochemical platform for sensitive determination of Cd(II) in environmental and tobacco samples
- 2022
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Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 1228
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Tidskriftsartikel (refereegranskat)abstract
- In this study, cetyltrimethylammonium bromide and zeolitic imidazolate framework-8 (ZIF-8) were first assembled via the chemical co-precipitation, and high-quality carbon-based metal-free nanomaterials were synthesized using a heat-treatment process. The internal and morphological characteristics of hexagonal Star ZIF-8 were investigated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical sensor with a good response to Cd(II) was prepared via square-wave anodic stripping voltammetry (SWASV) with Star ZIF-8 nanomaterial-modified glassy carbon electrodes. The main parameters were adjusted to obtain the optimal stripping response and a wide linear range. Concurrently, under the calculation of SWASV, the sensitivity of Star ZIF-8-Nafion/GCE to Cd(II) was increased by five orders of magnitude (0.5–230 μg/L), and the determination level was even low to 0.48 μg/L. Based on the high anti-interference ability and stability of the sensor, the application potential of Star ZIF-8 carbon-based metal-free nanomaterials for the detection of trace Cd(II) in was confirmed.
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| 2. |
- Qin, Haihong, et al.
(författare)
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A Comparative Study of Freewheeling Methods for eGaN HEMTs in a Phase-leg Configuration
- 2021
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Ingår i: IEEE Journal of Emerging and Selected Topics in Power Electronics. - 2168-6777 .- 2168-6785. ; 9:3, s. 3657-3670
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Tidskriftsartikel (refereegranskat)abstract
- Enhancement Gallium nitride high-electron mobility transistors (eGaN HEMTs) have been developed with lower conduction losses and higher switching speed compared to MOSFETs. Self-commutated reverse conduction (SCRC) mechanism determines no reverse recovery phenomenon but larger reverse conduction voltage drop of eGaN HEMTs than the body diodes in traditional Si MOSFETs or other freewheeling diodes. To reduce the large reverse conduction loss of eGaN HEMTs, the performance of different freewheeling methods for eGaN HEMTs in a phase-leg configuration is compared in this paper. Firstly, the reverse conduction mechanism and characteristics of eGaN HEMTs are analyzed. Then, four freewheeling ways for eGaN HEMTs are introduced, and the equivalent circuits are also given and analyzed. A double pulse test platform is established to further explore the influence of the freewheeling ways on the conduction and switching characteristics. Finally, the total losses of a phase-leg configuration with different freewheeling ways based on a buck converter is analyzed and compared. The paper aims to give a guidance to properly select freewheeling ways for eGaN HEMTs under different operation conditions.
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