Design and implementation of practical teaching of Programmable Devices and Applications

The practical teaching of “Programmable devices and Applications” course is a concentrated practice link with the curriculum theory teaching. This paper mainly from the teaching objec tives and content design, teaching implementation and curriculum thinking and politics, curriculum assessment and continuous improvement of three aspects of practical teaching process design and implementation. By optimizing the course objectives and contents of practice teaching and continuous improvement of teaching, we can achieve the graduation requirements of the course and fi nally realize the cultivation of students’ ability

New Insights Into Interactions of Presynaptic Calcium Channel Subtypes and SNARE Proteins in Neurotransmitter Release

Action potential (AP) induces presynaptic membrane depolarization and subsequent opening of Ca2+ channels, and then triggers neurotransmitter release at the active zone of presynaptic terminal. Presynaptic Ca2+ channels and SNARE proteins (SNAREs) interactions form a large signal transfer complex, which are core components for exocytosis. Ca2+ channels serve to regulate the activity of Ca2+ channels through direct binding and indirect activation of active zone proteins and SNAREs. The activation of Ca2+ channels promotes synaptic vesicle recruitment, docking, priming, fusion and neurotransmission release. Intracellular calcium increase is a key step for the initiation of vesicle fusion. Various voltage-gated calcium channel (VGCC) subtypes exert different physiological functions. Until now, it has not been clear how different subtypes of calcium channels integrally regulate the release of neurotransmitters within 200 μs of the AP arriving at the active zone of synaptic terminal. In this mini review, we provide a brief overview of the structure and physiological function of Ca2+ channel subtypes, interactions of Ca2+ channels and SNAREs in neurotransmitter release, and dynamic fine-tune Ca2+ channel activities by G proteins (Gβγ), multiple protein kinases and Ca2+ sensor (CaS) proteins

Structural, Optical and Multiferroic Properties of (Nd, Zn)-Co-doped BiFeO3 Nanoparticles

The pure BiFeO3 (BFO) and (Nd, Zn)-co-doped BFO nanoparticles were prepared by a sol-gel method. The crystal structure and optical and multiferroic properties of the samples were systematically investigated. Rietveld refinement showed that the samples crystallized in rhombohedral R3c structure. In UV-visible diffuse absorption spectra, an apparent blue shift can be observed after co-doping, which indicates a possible application in photocatalyst and photoconductive devices. Compared with a pure BFO sample, the leakage current density of the x = 0.05 sample decreases about 3 orders of magnitude. The remanent magnetization (Mr) of the x = 0.10 sample reaches 0.105 emu/g while the coercive field (Hc) is as high as 7.0 kOe. The (Nd, Zn) co-doping into BFO nanoparticles has been proved to be an effective way to improve the optical and multiferroic properties

Double-shell CeO2:Yb, Er@SiO2@Ag upconversion composite nanofibers as an assistant layer enhanced near-infrared harvesting for dye-sensitized solar cells

Double-shell CeO2:Yb,Er@SiO2@ Ag upconversion composite nanofibers are synthesized by electro- spinning and subsequent process. CeO2:Yb,Er@SiO2@ Ag nanofibers show high upconversion luminescence property due to the coating of amorphous SiO2 and the surface plasmon resonance effect of Ag nanoparticles. CeO2:Yb,Er@SiO2@ Ag nanofibers act as an assistant layer in dye-sensitized solar cells (DSSCs) and enhance the photoelectric conversion efficiency (PCE) to 8.17%. The photocurrent-voltage characteristic is obtained under 980 nm laser as illumination light source. In addition, the absorption of the incident photon-to-current conversion efficiency curve in 900-1000 nm near-infrared light confirms that the introduction of the upconversion nanomaterial broadens the absorption range, improves the utilization rate of the sunlight and increases the PCE of DSSCs. (C) 2018 Elsevier B.V. All rights reserved

Nitrogen-doped carbon coated ZeO2 as a support to Pt nanoparticles in the oxygen reduction reaction

A new nitrogen-doped carbon (CNx) support for Pt electrocatalysts was prepared by carbonizing polypyrrole on the surface of ZrO2 (ZrO2@CNx) at high temperature. Well-dispersed Pt nanoparticles were easily formed on the ZrO2@CNx. The electrocatalyst was characterized by FT-IR, XRD, TEM, XPS. The electrochemical performances indicate that the presence of ZrO2 modified the electro-structure of Pt on the catalyst surface and that ZrO2@CNx had superior oxygen reduction activity compared to a nitrogen-doped carbon coated carbon (C@CNx).Web of Scienc

Ethanol oxidation activity and structure of carbon-supported Pt-modified PdSn-SnO2 influenced by different stabilizers

PdSn-SnO2 nanoparticles supported on Vulcan XC-72 carbon were synthesized by chemical reduction in the presence of three different stabilizing agents: ethylene diamine tetra-acetic acid (EDTA), sodium citrate (Nacitrate) and hexamethylenetetramine (HMTA). TEM analysis showed that PdSn-SnO2 /C catalyst made using the HMTA stabilizer produced the smallest particle size. XRD analysis detected the presence of PdSn alloy and the SnO2 phase in all three PdSn-SnO2 /C samples, and showed that PdSn-SnO2 (HMTA) had the smallest lattice parameter. After PdSn-SnO2 samples were modified by Pt, the particle size distribution and average size of nanoparticles of Pt-PdSn-SnO2 did not obviously change, and the fcc structure of PdSn in all three samples was retained. XPS measurement showed a higher upshift of Pt 4f binding energy occurred for Pt/PdSn-SnO2 /C (HMTA) compared to those of Pt/PdSn-SnO2 /C (EDTA) and Pt/PdSn-SnO2 /C (Nacitrate). Pt/PdSn-SnO2 /C (HMTA) was also found to have the highest CO and ethanol oxidation activity among the three catalysts.Web of Scienc

Montmorillonite modified by CNx supported Pt for methanol oxidation

A composite support based on nature clay, i.e. montmorillonite (MMT), shows great promise as support materials for Pt electrocatalyst for the methanol oxidation reaction in fuel cell anodes. The reported composite support (CNx-MMT) was prepared via carbonizing MMT which was covered by N-contented polymer. X-ray diffraction and transmission electron microscopy results showed that Pt nanoparticles can be well-dispersed on the composite support with highly dispersed tiny crystal Pt nanoparticles. Cyclic voltammetry measurements showed that the Pt/CNx-MMT has the enhanced electrocatalytic activity in methanol oxidation reaction. The developed Pt catalyst supported on new composite support is catalytically more active for methanol electrooxidation than Pt supported on the conventional carbon support and shows good stability, offering promising potential for application of MMT as support for fuel cell electrocatalysis.Web of Scienc

Synthesis of carbon-supported PdSn–SnO2 nanoparticles with different degrees of interfacial contact and enhanced catalytic activities for formic acid oxidation

The conjunction of the PdSn alloy and SnO2 is of interest for improving catalytic activity in formic acid oxidation (FAO). Here, we report the synthesis of PdSn–SnO2 nanoparticles and a study of their catalytic FAO activity. Different degrees of interfacial contact between SnO2 and PdSn were obtained using two different stabilizers (sodium citrate and EDTA) during the reduction process in catalyst preparation. Compared to the PdSn alloy, PdSn–SnO2 supported on carbon black showed enhanced FAO catalytic activity due to the presence of SnO2 species. It was also found that interfacial contact between the PdSn alloy and the SnO2 phase has an impact on the activity towards CO oxidation and FAO.Web of Scienc

Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation: TiO2 nanoparticles promoted PtRu/C catalyst for MOR

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO2-promoted PtRu/C catalysts were prepared by directly mixing TiO2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electro-oxidation. The value of the apparent activation energy (Ea) for TiO2-PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO2 nanoparticles into PtRu/ C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.Web of Scienc

CNx-modified Fe3O4 as Pt nanoparticle support for the oxygen reduction reaction

A novel electrocatalyst support material, nitrogendoped carbon (CNx)-modified Fe3O4 (Fe3O4-CNx), was synthesized through carbonizing a polypyrrole-Fe3O4 hybridized precursor. Subsequently, Fe3O4-CNx-supported Pt (Pt/Fe3O4-CNx) nanocomposites were prepared by reducing Pt precursor in ethylene glycol solution and evaluated for the oxygen reduction reaction (ORR). The Pt/Fe3O4-CNx catalysts were characterized by X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The electrocatalytic activity and stability of the as-prepared electrocatalysts toward ORR were studied by cyclic voltammetry and steady-state polarization measurements. The results showed that Pt/ Fe3O4-CNx catalysts exhibited superior catalytic performance for ORR to the conventional Pt/C and Pt/C-CNx catalysts.Web of Scienc