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Your search keyword '"Lei, Yong"' showing total 34 results
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34 results on '"Lei, Yong"'

3. Unique gap-related SERS behaviors of p -aminothiophenol molecules absorbed on TiO2 surface in periodic TiO2/Ni nanopillar arrays.

Author

Wu, Zhijun, Zheng, Chunfang, Lin, Qi, Fu, Qun, Zhao, Huaping, and Lei, Yong

Subjects
RAMAN scattering, SURFACE plasmon resonance, SERS spectroscopy, ABSORPTION spectra, MOLECULES
Abstract

We observed a unique interpillar gap-related surface-enhanced Raman scattering (SERS) behavior of p -aminothiophenol (PATP) molecules from periodic TiO2 nanopillar arrays with three gap sizes of 191, 297 and 401 nm, which is completely different from that on Ag and Ni nanopillar arrays. Especially, the gap-size-dependent charge-transfer (CT) resonance enhancement from TiO2/Ni has been indicated through comparisons of variation trend of SERS intensities with inter-pillar gap size between TiO2/Ni and Ag/TiO2/Ni as well as Ni nanoarrays, and been confirmed by spectra of ultraviolet–visible absorption and photoluminescence. Results demonstrate that the CT resonance enhancement is more susceptible to the change of the gap size compared with the surface plasmon resonance (SPR) enhancement in TiO2/Ni nanoarrays. Hence, SPR and CT enhancement showing different variation trend and rate with the gap size that leads to a different relative contribution of CT resonance to the overall SERS enhancement as gap size changes, and consequently results in a unique gap-related SERS behavior for TiO2/Ni nanoarrays. The present study is not only helpful for investigating SERS mechanism for semiconductors but also providing a method to design and optimize periodic metal/semiconductor SERS substrates in a controllable way. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Research on the Transformation Area Deformation of Topographic Map Under the Background of 'Multi Conformity'

Author

Wang Lihui, Lei Yong, Ren Chuanjian, Wang Zhihong, and Chen Zhu

Subjects
Software, Transformation (function), Digital mapping, Geographic coordinate conversion, Projection (mathematics), business.industry, Computer science, Coordinate system, Computer vision, Artificial intelligence, business, Topographic map, Plot (graphics)
Abstract

The urban independent coordinate system based on CGCS2000 has a relatively strict conversion correspondence with CGCS2000 coordinate system. Based on the surveying and mapping technical force of class a unit, the conversion of control points can be realized and high precision can be achieved. In the process of topographic map transformation, due to the influence of side length projection deformation, it will have an impact on the area of engineering construction plot. Through the coordinate conversion function of the digital mapping software, the topographic map is transformed to explore the change rate of the converted area and provide decision-making basis for the planning and construction departments.

Published
2021

20. Exploration on the selection of Engineering Project coordinate system based on 'Integration of multiple regulations'

Author

Lei Yong, Wang Zhihong, Wang Lihui, Chen Zhu, and Ren Chuanjian

Subjects
Value (ethics), Computer science, Process (engineering), media_common.quotation_subject, Scale (chemistry), Coordinate system, Premise, Quality (business), Projection (set theory), Natural resource, Construction engineering, media_common
Abstract

In order to avoid the problem that the side length projection deformation value is too large in the process of "multi-gauge in one" coordinate system selection, different coordinate system methods are adopted for planning drawings and engineering construction respectively. In the process of planning, CGCS2000, is comprehensively adopted in the project construction, and the independent coordinate system of the central city of Bijie City is comprehensively adopted. By means of surveying and mapping technology, the connection between the two coordinate systems is established to meet the different needs of the natural resources system and the engineering construction department on a small scale. Under the premise of ensuring the quality and safety of the project construction, it meets the requirements of the Ministry of Natural Resources, and lays a solid surveying and mapping foundation for "multi-regulation integration".

Published
2021

24. Application of BeiDou Navigation Satellite System in Anti-Drowning System

Author

Chen Minghao, Gou Wensha, Qin Yong, Li Wenrui, Lei Yong, and Sun Tianran

Subjects
Computer science, GSM, business.industry, BeiDou Navigation Satellite System, Real-time computing, Global Positioning System, Satellite system, Exact location, General Packet Radio Service, business, Internet of Things
Abstract

Due to the high frequent drowning accident, a new type of drowning-preventing device established on the base ofBeiDou Navigation Satellite System, using the compatibility of GPS tech, GSM, GPRS and other Internet of Things technology as well as Vital Signs Detection technology is designed. The situation whether a person is in drowning is judged by the device monitoring the heart rate and oxygen saturation. And the device utilizes Global Positioning System module to find exact location and uses GPRS to send the information of life signal and position. Based on the experiment, this system can decrease the rate of the drowning accident tosome extent.

Published
2018

25. An efficient nanopatterning strategy for controllably fabricating ultra-small gaps as a highly sensitive surface-enhanced Raman scattering platform.

Author

Yuan, Ning, Zhao, Huaping, Zheng, Chunfang, Zheng, Xianzheng, Fu, Qun, Wu, Minghong, and Lei, Yong

Subjects
SERS spectroscopy, NANOPATTERNING, RAMAN scattering, MAGNITUDE (Mathematics)
Abstract

The realization of large-scale and high-density gaps with sizes as small as possible is crucial for designing ultra-sensitive surface-enhanced Raman scattering (SERS) substrates. As known, the ultrathin alumina mask (UTAM) surface nanopatterning technique allows the fabrication of periodic nanoparticle (NP) arrays with 5 nm gaps among the NPs, however, it still faces a significant challenge in realizing the reliable distribution of nanogaps over a large area, because of the unavoidable collapse of the UTAM pore wall during the traditional one-step homothermal pore-widening process. Herein, an efficient two-step poikilothermal pore-widening process was developed to precisely control the pore wall etching of a UTAM, enabling effectively avoiding the fragmentation of the UTAM and finally obtaining a large-scale UTAM with a pore wall thickness of about 5 nm. As a result, large-scale NP arrays with high-density sub-5 nm and even smaller gaps between the neighboring NPs have been realized through applying the as-prepared UTAM as the nanopatterning template. These NP arrays with sub-5 nm gaps show ultrahigh SERS sensitivity (signal enhancement improved by an order of magnitude compared with NP arrays with 5 nm gaps) and good reproducibility, which demonstrates the practical feasibility of this promising two-step pore-widening UTAM technique for the fabrication of high-performance active SERS substrates with large-scale ultra-small nanogaps. [ABSTRACT FROM AUTHOR]

Published
2020
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33. Field plate engineering for GaN-based Schottky barrier diodes

Author

Zhang Rong, Lu Hai, Zheng Youdou, Shi Hongbiao, Chen Dun-Jun, and Lei Yong

Subjects
Permittivity, Materials science, business.industry, Schottky barrier, Schottky diode, Gallium nitride, Semiconductor device, Dielectric, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, chemistry, Materials Chemistry, Optoelectronics, Electrical and Electronic Engineering, business, Critical field, Diode
Abstract

The practical design of GaN-based Schottky barrier diodes (SBDs) incorporating a field plate (FP) structure necessitates an understanding of their working mechanism and optimization criteria. In this work, the influences of the parameters of FPs upon breakdown of the diode are investigated in detail and the design rules of FP structures for GaN-based SBDs are presented for a wide scale of material and device parameters. By comparing three representative dielectric materials (SiO2, Si3N4 and Al2O3) selected for fabricating FPs, it is found that the product of dielectric permittivity and critical field strength of a dielectric material could be used as an index to predict its potential performance for FP applications.

Published
2013

34. Magnetoresistance of Electrons Channelled by Microscopic Magnetic Field Modulation.

Author

Dai Bo, Liu Xiao, Lei Yong, and Alain Nogaret

Subjects
ELECTRON gas, MAGNETORESISTANCE, ION channels, MAGNETIC fields, MULTILAYERED thin films, SEMICONDUCTOR films, MICROFABRICATION
Abstract

We report the magnetoresistance of two-dimensional electron gas, which is made of GaAs based epitaxial multilayers and laterally subjected to a periodic magnetic field. The modulation field is produced by an array of submicrometre ferromagnets fabricated at the surface of the heterostructure. The magnetoresistance of about 20% is found at low temperature 80 K. The measurement is in quantitative agreement with semiclassical simulations, which reveal that the magnetoresistance is due to electrons trapped in snake orbits along lines of zero magnetic field. [ABSTRACT FROM AUTHOR]

Published
2009
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