Search

Your search keyword '"Song, Changqing"' showing total 494 results
Start Over Author "Song, Changqing"
494 results on '"Song, Changqing"'

113. The role of 2-ethylhexanoic acid in manipulating the morphology and upconversion of flame-made Y2O3:Yb3+/Ho3+ nanoparticles towards remote temperature sensing.

Author

Hu, Shuai, Yuan, Maohui, Song, Changqing, Han, Kai, Wang, Linxuan, Huang, Hanchang, Cui, Wenda, Yang, Zining, and Wang, Hongyan

Subjects
YTTERBIUM, PHOTON upconversion, REMOTE sensing, RARE earth ions, FLAME spraying, NANOPARTICLES
Abstract

Flame spray pyrolysis (FSP) is a potential strategy to scale-up the fabrication of upconversion nanoparticles (UCNPs) from the laboratory to industrial-scale production. The traditional FSP method involves the addition of 2-ethylhexanoic acid (2-EHA) to the precursors to obtain pure homogeneous ultrafine nanoparticles. However, there is still a lack of investigation into how the physical and optical properties are affected by 2-EHA. Here, for the first time, we report the role of 2-EHA in manipulating the morphology, size, and upconversion (UC) properties of Yb3+/Ho3+ co-doped Y2O3 UCNPs. The Y2O3:Yb3+/Ho3+ UCNPs were synthesized by adjusting the molar ratios of 2-EHA to trivalent rare earth ions (RE3+) in the precursor solution via the FSP method. The influence on the morphology and upconversion luminescence (UCL) properties of the UCNPs by 2-EHA was studied in detail. As the ratio of 2-EHA to RE3+ (2-EHA/RE3+) in the precursors increases from 0 to 3, the synthesized UCNPs initially form a mixture of large hollow particles and homogeneous ultrafine nanoparticles at low ratios and then uniform ultrafine nanoparticles at relatively high ratios. The typical green (550 nm) and red (667 nm) UCL reduce as the 2-EHA/RE3+ ratio increases. Moreover, the effect of 2-EHA on the temperature sensing behavior of the Y2O3:Yb3+/Ho3+ UCNPs was evaluated via the fluorescence intensity ratio (FIR) method based on the non-thermally coupled 5F4/5S2 and 5F5 levels of Ho3+ ions. The highest absolute sensitivity (SA) and relative sensitivity (SR) of 6.259% and 0.483% K−1 at 323 K, respectively, were determined and the sensitivity dependence on the 2-EHA/RE3+ ratio of the UCNPs was comparatively estimated. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

114. Sandwich-type CoSe2-CNWs@rGO/S composites with efficient trapping and catalytic conversion of polysulfides in lithium–sulfur batteries.

Author

Zhou, Yuxiang, Zhang, Jianwei, Zhao, Chenyuan, Shi, Tianyu, Yin, Haihong, Song, Changqing, Qin, Lin, Wang, Zhiliang, Shao, Haibao, and Yu, Ke

Subjects
LITHIUM sulfur batteries, POLYSULFIDES, CARBON nanowires, SANDWICH construction (Materials), CHARGE exchange
Abstract

Although lithium–sulfur batteries (LSBs) are very promising in energy storage devices, their low conductivity, shuttle effect, and volume expansion unfavorably lead to sluggish kinetics and worsening electrochemical performance. To address these problems, we firstly prepared conductive carbon nanowires embedded with lithiophilic CoSe2 nanoparticles (CoSe2-CNWs), and utilized CoSe2-CNWs to construct reduced graphene oxide (rGO) sheets; thereby, sandwich-type CoSe2-CNWs@rGO composites were assembled. CoSe2-CNWs@rGO composites were taken as the sulfur host. Due to the alternating rGO sheets and active sulfur, the special sandwich structure can maximize the use of sulfur, confine polysulfides physically, favor electron transport, and cushion the volume change during cycling. The interlayer CoSe2-CNWs network also can entrap polysulfides chemically, promote the electron transfer, and improve the reaction kinetics, owing to the synergetic merits of high polarity and conductivity. Compared with CoSe2-CNWs/S and Co-CNWs/S, the CoSe2-CNWs@rGO/S cathode shows a significant improvement in cell performance. Its specific capacity decreases from 1137.9 mA h g−1 at 0.1 C to 649.7 mA h g−1 at 2 C, demonstrating the optimal rate performance. The cycling capacity also slowly reduces from 975.4 mA h g−1 to 839.7 mA h g−1 after 150 cycles at 0.5 C, showing a high retention of 86.1% with a tiny average fading rate (0.093%). [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

117. Novel hybrid coupling of ecohydrology and socioeconomy at river basin scale: A watershed system model for the Heihe River basin

Author

Li, Xin, primary, Zhang, Ling, additional, Zheng, Yi, additional, Yang, Dawen, additional, Wu, Feng, additional, Tian, Yong, additional, Han, Feng, additional, Gao, Bing, additional, Li, Hongyi, additional, Zhang, Yanlin, additional, Ge, Yingchun, additional, Cheng, Guodong, additional, Fu, Bojie, additional, Xia, Jun, additional, Song, Changqing, additional, and Zheng, Chunmiao, additional

Published
2021
Full Text
View/download PDF

120. Supplementary document for Achieving tunable multicolor display and sensitive temperature sensing in self-sensitization of erbium-doped CaF2 nanocrystals under 808, 980 and 1532 nm irradiation - 5253138.pdf

Author

yang, xu, Wang, Linxuan, Wang, Rui, Yang, Zining, Song, Changqing, Yuan, Maohui, Han, Kai, Lan, Sheng, Wang, Hongyan, and Xu, Xiaojun

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Physics::Optics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The UC emission spectra, UCL intensity dependence on the pump power density and decay curves of UC emissions of the CaF2 UCNCs under multi-wavelength excitation.

Published
2021
Full Text
View/download PDF

121. Enhanced Long-Range Surface Plasmon Effect Based on Zr2CO2 MXene and MoSe2 Heterostructures for SPR Biosensors With High FOM

Author

Wang, Zhenguo, Yu, Mei, Song, Changqing, Li, Ke, Li, Hongwei, and Yin, Haihong

Abstract

MXenes-based van der Waals heterojunction materials with excellent chemical stability and bioaffinity have been widely used in biosensing in recent years. We propose a new MoSe2@Zr2CO2 heterostructure as a long-range surface plasmon resonance (LRSPR) sensor based on the Kretschmann configuration from simulation and optimize the structure parameters algorithmically. First, we investigate the effect of different layers of MoSe2@Zr2CO2 heterojunction on the LRSPR wave. The results show that the optimal number of layers for heterogeneous layers is 18. Second, the effects of dielectric thickness and refractive index (RI) on sensitivity are investigated in depth, and optimized structural parameters are obtained. Finally, the effect of prisms with different refractive coefficients on the sensor performance is also discussed, and it is shown that prisms with lower refractive coefficients can effectively improve the sensitivity performance of the sensor. The sensor response performance to biomolecules is greatly enhanced due to the gain of light absorption and SPR. Compared with the conventional precious metal Au-based (50 nm) thin-film SPR sensor, the figure of merit (FOM) of the sensor is improved by a factor of 8.16, and higher sensitivity (92.48°/RIU) and quality factor (QF) (319.63 RIU−1) are obtained in the visible range.

Published
2023
Full Text
View/download PDF

123. Cropland redistribution to marginal lands undermines environmental sustainability

Author

Kuang, Wenhui, primary, Liu, Jiyuan, additional, Tian, Hanqin, additional, Shi, Hao, additional, Dong, Jinwei, additional, Song, Changqing, additional, Li, Xiaoyong, additional, Du, Guoming, additional, Hou, Yali, additional, Lu, Dengsheng, additional, Chi, Wenfeng, additional, Pan, Tao, additional, Zhang, Shuwen, additional, Hamdi, Rafiq, additional, Yin, Zherui, additional, Yan, Huimin, additional, Yan, Changzhen, additional, Wu, Shixin, additional, Li, Rendong, additional, Yang, Jiuchun, additional, Dou, Yinyin, additional, Wu, Wenbin, additional, Liang, Liqiao, additional, Xiang, Bao, additional, and Yang, Shiqi, additional

Published
2021
Full Text
View/download PDF

125. Incorporation ZnS quantum dots into carbon nanotubes for high-performance lithium-sulfur batteries

Author

Lin Qin, Ke Yu, Chenyuan Zhao, Song Changqing, Zhiliang Wang, Haibao Shao, Shi Tianyu, Haihong Yin, and Yin Chuan

Subjects
Materials science, chemistry.chemical_element, Bioengineering, 02 engineering and technology, Carbon nanotube, 010402 general chemistry, Electrochemistry, 01 natural sciences, Redox, law.invention, law, General Materials Science, Electrical and Electronic Engineering, Mechanical Engineering, General Chemistry, 021001 nanoscience & nanotechnology, Sulfur, 0104 chemical sciences, Dielectric spectroscopy, chemistry, Chemical engineering, Mechanics of Materials, Chemisorption, Quantum dot, 0210 nano-technology, Faraday efficiency
Abstract

Constructing sulfur hosts with high electronic conductivity, large void space, strong chemisorption, and rapid redox kinetics is critically important for their practical applications in lithium–sulfur batteries (LSBs). Herein, by coupling ZnS quantum dots (QDs) with carbon nanotubes (CNTs), one multifunctional sulfur host CNT/ZnS-QDs is designed via a facile one-step hydrothermal method. SEM and TEM analyses reveal that small ZnS-QDs (−1 at 0.2 C to 544 mAh g−1 at 2.0 C, showing rate capability much higher than CNT/S and other CNT/ZnS-QDs/S samples. After 150 cycles, the cyclic capacity at 0.5 C exhibits a slow reduction from 1051 mAh g−1 to 771 mAh g−1, showing a high retention of 73.4% with a coulombic efficiency of over 99%. The electrochemical impedance spectroscopy analyses demonstrate that this special architecture juggles high conductivity and excellent confinement of polysulfides, which can significantly suppress the notorious shuttle effect and accelerate the redox kinetics. The strategy in this study provides a feasible approach to design efficient sulfur hosts for realizing practically usable LSBs.

Published
2020

135. Employing synergetic effect of ZnSe quantum dots and layered Ni(OH)2 to boost the performance of lithium–sulfur cathodes

Author

Lin Qin, Ke Yu, Shi Tianyu, Desong Guo, Chenyuan Zhao, Song Changqing, Haibao Shao, Haihong Yin, Yuxiang Zhou, and Zhiliang Wang

Subjects
Materials science, Mechanical Engineering, chemistry.chemical_element, Bioengineering, General Chemistry, Electrochemistry, Sulfur, Cathode, law.invention, chemistry.chemical_compound, chemistry, Chemical engineering, Mechanics of Materials, law, Quantum dot, General Materials Science, Zinc selenide, Electrical and Electronic Engineering, Dissolution, Polysulfide, Sulfur utilization
Abstract

The low sulfur utilization, cycling instability, and sluggish kinetics are the critical obstructions to practical applications of lithium-sulfur batteries (LSBs). Constructing sulfur hosts with high conductivity, suppressed shuttle effect, and rapid kinetics is essential for their practical application in LSBs. Here, we synthetically utilized the merits of ZnSe quantum dots (QDs) and layered Ni(OH)2to boost the performance of LSBs. A novel core-shell ZnSe-CNTs/S@Ni(OH)2was constructed using the ZnSe-CNTs network as framework to load sulfur and following with Ni(OH)2encapsulation. The CNT network decorated with ZnSe QDs not only serves as a conductive framework providing fast electron/ion transfer channels, but also limits polysulfide diffusion physically and chemically. Layered Ni(OH)2, the wrinkled encapsulation, not only permits fast electron/ion transfer, but also buffers the expansion, confines active materials, and limits the polysulfide dissolution chemically. When used as a cathode, ZnSe-CNTs/S@Ni(OH)2presents enhanced electrochemistry performance compared with ZnSe-CNTs/S and CNTs/S. The average specific capacity decreases from 1021.9 mAh g-1at 0.2 C to 665.0 mAh g-1at 2 C, showing rate capacity much higher than ZnSe-CNTs/S and CNTs/S. After 150 cycles, the capacity at 0.5 C slowly reduces from 926.7 to 789.0 mAh g-1, showing high retention of 85.1%. Therefore, our investigation provides a new strategy to construct a promising sulfur cathode for LSBs.

Published
2021

137. Visualizing clustering characteristics of multidimensional arable land quality indexes at the county level in mainland China.

Author

Ye, Sijing, Song, Changqing, Gao, Peichao, Liu, Chenyu, and Cheng, Changxiu

Subjects
*ECOSYSTEMS, *LAND use, *INDEXES, *LAND resource
Abstract

The evaluation of the arable land ecosystem services capacity and arable land use intensity is important for recognizing regional key factors that impact the change of arable land attributes. A chronic lack of cooperation persists between these two fields of study, which makes providing sufficient information to support developing arable land use management and control policies difficult. In this study, the clustering characteristics of four arable land quality indexes have been assessed using the K-means algorithm to indicate the regional coordination between arable land resource protection and arable land use. The clustering results have been visualized using circular cartogram. This study can contribute to the identification of key regional challenges in China's arable land use and help to build the framework of other countries' arable land protection policies. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results