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Xuchang, China

Yidong Z.,Xuchang University
Industrial Lubrication and Tribology | Year: 2012

Purpose - The purpose of this paper is to prove the self-repairing Cu film of Cu-DDP additive in base lubricating oil. Design/methodology/approach - Cu nanoparticles coated with dialkydithiophosphate (Coded as Cu-DDP) were synthesized ITin situ/IT by redox method. The size and structure of Cu-DDP were characterized using transmission electronic microscopy (TEM) and electronic diffraction (ED) analysis. The self-repairing performance of Cu-DDP as additive in base lubricating oil was evaluated by MRH-3 stock-on-ring testing machine. Scanning electronic microscopy (SEM), UMT-2 tribometer, X-ray photoelectron spectroscopy (XPS), and energy-dispersive spectrum (EDS) were used to study the self-repairing Cu film on the stock. Findings - The test results showed that the modified Cu-DDP additive in base lubricating oil exhibited excellent anti-wear and friction-reducing properties, as well as good self-repairing performance. Research limitations/implications - The thickness of the self-repairing Cu film was unknown, and the relationship between thickness of the Cu film and load, time, rotation velocity was still necessary to investigate. Practical implications - The Cu-DDP additive was involved P and S elements, therefore, it is still promising to seek environment friendly additive without P and S elements. Originality/value - For the first time, MRH-3 stock-on-ring testing machine, Scanning electronic microscopy (SEM), UMT-2 tribometer, X-ray photoelectron spectroscopy (XPS), and energy-dispersive spectrum (EDS) were widely used to study the self-repairing Cu film on the stock. © 2012 Emerald Group Publishing Limited. All rights reserved. Source

Li M.,Xuchang University
Communications in Theoretical Physics | Year: 2013

In this paper, we obtain considerable spin-orbit (SO) parameters in Al xGa1-xN/GaN quantum wells (QWs) with sheet carrier concentration Ns = 120 × 1011/cm2. With increasing Al content (x) of the barrier, the SO parameters increase as a whole, and the two major contributions are found to be the decrease of the expansion region of the envelope functions and the increase of the polarized electric field in the well. Compared with the Rashba parameters for the first two subbands, the intersubband SO parameter is a bit smaller and varies more slowly with x. The results indicate the SO parameters, especially the Rashba parameters can be engineered by the Al composition of the barrier, which may be helpful to the spin manipulation of III-nitride low-dimensional heterostructures. © 2013 Chinese Physical Society and IOP Publishing Ltd. Source

Feng Z.-B.,Xuchang University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

In this Brief Report, we propose a theoretical scheme to transfer quantum states between superconducting charge qubits and semiconductor spin qubits in a circuit QED device. Under dispersive conditions, resonator-assisted state transfer between qubits can be performed controllably only by addressing the flux bias applied to the charge qubits. The low infidelity and existing advantages show that the proposal may provide an effective route toward scalable quantum-information transfer with solid-state hybrid qubits. © 2012 American Physical Society. Source

He W.,Xuchang University | He W.,U.S. Food and Drug Administration | Kim H.-K.,U.S. Food and Drug Administration | Wamer W.G.,U.S. Food and Drug Administration | And 3 more authors.
Journal of the American Chemical Society | Year: 2014

Semiconductor nanostructures with photocatalytic activity have the potential for many applications including remediation of environmental pollutants and use in antibacterial products. An effective way for promoting photocatalytic activity is depositing noble metal nanoparticles (NPs) on a semiconductor. In this paper, we demonstrated the successful deposition of Au NPs, having sizes smaller than 3 nm, onto ZnO NPs. ZnO/Au hybrid nanostructures having different molar ratios of Au to ZnO were synthesized. It was found that Au nanocomponents even at a very low Au/ZnO molar ratio of 0.2% can greatly enhance the photocatalytic and antibacterial activity of ZnO. Electron spin resonance spectroscopy with spin trapping and spin labeling was used to investigate the enhancing effect of Au NPs on the generation of reactive oxygen species and photoinduced charge carriers. Deposition of Au NPs onto ZnO resulted in a dramatic increase in light-induced generation of hydroxyl radical, superoxide and singlet oxygen, and production of holes and electrons. The enhancing effect of Au was dependent on the molar ratio of Au present in the ZnO/Au nanostructures. Consistent with these results from ESR measurements, ZnO/Au nanostructures also exhibited enhanced photocatalytic and antibacterial activity. These results unveiled the enhanced mechanism of Au on ZnO and these materials have great potential for use in water purification and antibacterial products. © 2013 American Chemical Society. Source

Feng Z.-B.,Xuchang University | Feng Z.-B.,CAS Wuhan Institute of Physics and Mathematics
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

We propose a potentially practical scheme for quantum state transfer between a Cooper-pair box circuit and an electron spin ensemble of diamond nitrogen-vacancy (NV) centers. Both subsystems are placed into a common circuit QED and can be modeled as effective three-level subsystems under the appropriate external biases. Due to significant suppression of the photon decay, the robust state transfer between the two subsystems can be accomplished by using the technique of stimulated Raman adiabatic passage by individual microwave pulses, where a superconducting coplanar resonator serves as the quantum data bus. Numerical simulations show that the present scheme could offer a viable route towards robust quantum state transfer in hybrid solid-state systems. © 2015 American Physical Society. Source

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