8 research outputs found
Effects of Pre-Annealing on the Radiation Resistance of ZnO Nanorods
Ion implantation is usually used for semiconductor doping and isolation, which creates defects in semiconductors. ZnO is a promising semiconductor and has a variety of applications, such as for use in transparent electronics, optoelectronics, chemical and biological sensors, etc. In this work, ZnO nanorods were grown on Si (100) substrates by the process of chemical bath deposition and then annealed in an O2 atmosphere at 350 and 600 °C for 1 h to introduce different kinds of defects. The as-grown nanorods and the nanorods that annealed were irradiated simultaneously by 180 keV H+ ions at room temperature with a total dose of 8.0×1015 ions/cm2. The radiation effects of the H+ ions, effects of the pre-existed defects on the radiation resistance, and the related mechanisms under irradiation were investigated. The crystal and optical properties of the ZnO nanorods after H+ ion irradiation were found to depend upon the pre-existed defects in the nanorods. The existence of the appropriate concentration of oxygen interstitials in the ZnO nanorods caused them to have good radiation resistance. The thermal effects of irradiation played an important role in the property variation of nanorods. The temperature of the nanorods under 180 keV H+ ion bombardment was around 350 °C
Effects of Pre-Annealing on the Radiation Resistance of ZnO Nanorods
Ion implantation is usually used for semiconductor doping and isolation, which creates defects in semiconductors. ZnO is a promising semiconductor and has a variety of applications, such as for use in transparent electronics, optoelectronics, chemical and biological sensors, etc. In this work, ZnO nanorods were grown on Si (100) substrates by the process of chemical bath deposition and then annealed in an O2 atmosphere at 350 and 600 °C for 1 h to introduce different kinds of defects. The as-grown nanorods and the nanorods that annealed were irradiated simultaneously by 180 keV H+ ions at room temperature with a total dose of 8.0×1015 ions/cm2. The radiation effects of the H+ ions, effects of the pre-existed defects on the radiation resistance, and the related mechanisms under irradiation were investigated. The crystal and optical properties of the ZnO nanorods after H+ ion irradiation were found to depend upon the pre-existed defects in the nanorods. The existence of the appropriate concentration of oxygen interstitials in the ZnO nanorods caused them to have good radiation resistance. The thermal effects of irradiation played an important role in the property variation of nanorods. The temperature of the nanorods under 180 keV H+ ion bombardment was around 350 °C
Jerk Analysis of a Power-Split Hybrid Electric Vehicle Based on a Data-Driven Vehicle Dynamics Model
Given its highly coupled multi-power sources with diverse dynamic response characteristics, the mode transition process of a power-split Hybrid Electric Vehicle (HEV) can easily lead to unanticipated passenger-felt jerks. Moreover, difficulties in parameter estimation, especially power-source dynamic torque estimation, result in new challenges for jerk reduction. These two aspects entangle with each other and constitute a complicated coupling problem which obstructs the realization of a valid anti-jerk method. In this study, a vehicle dynamics model with reference to a data-driven modeling method is first established, integrating a full-time artificial neural network engine dynamic model that can accurately predict engine dynamic torque. Then the essential reason for the occurrence of vehicle jerks in real driving conditions is analyzed. Finally, to smooth the mode transition process, a more practical anti-jerk strategy based on power-source torque changing rate limitation (TCRL) is proposed. Verification studies indicate that the data-driven vehicle dynamics model has enough accuracy to reflect the vehicle dynamic characteristics, and the proposed TCRL strategy could reduce the vehicle jerk by up to 85.8%, without any sacrifice of vehicle performance. This research provides a feasible method for precise modeling of vehicle dynamics and a reference for improving the riding comfort of hybrid electric vehicles
Oxygen Vacancy Induced Atom-Level Interface in Z‑Scheme SnO<sub>2</sub>/SnNb<sub>2</sub>O<sub>6</sub> Heterojunctions for Robust Solar-Driven CO<sub>2</sub> Conversion
The modulation of Z-scheme charge
transfer is essential
for efficient
heterostructure toward photocatalytic CO2 reduction. However,
constructing a compact hetero-interface favoring the Z-scheme charge
transfer remains a great challenge. In this work, an interfacial Nb–O–Sn
bond and built-in electric field-modulated Z-scheme Ov-SnO2/SnNb2O6 heterojunction was prepared
for efficient photocatalytic CO2 conversion. Systematic
investigations reveal that an atomic-level interface is constructed
in the Ov-SnO2/SnNb2O6 heterojunction. Under simulated sunlight irradiation, the obtained
Ov-SnO2/SnNb2O6 photocatalyst
exhibits a high CO evolution rate of 147.4 μmol h–1 g–1 from CO2 reduction, which is around
3-fold and 3.3-fold of SnO2/SnNb2O6 composite and pristine SnNb2O6, respectively,
and favorable cyclability by retaining 95.8% rate retention after
five consecutive tests. As determined by electron paramagnetic resonance
spectra, in situ Fourier transform infrared spectra, and density functional
theory calculations, Nb–O–Sn bonds and built-in electric
field induced by the addition of oxygen vacancies jointly accelerate
the Z-scheme charge transfer for enhanced photocatalytic performance.
This work provides a promising route for consciously modulating Z-scheme
charge transfer by atomic-level interface engineering to boost photocatalytic
performance