Search

Your search keyword '"Zheng, Fengying"' showing total 194 results
Start Over Author "Zheng, Fengying"
194 results on '"Zheng, Fengying"'

20. Dual-functional CeOx fence promoting Au nanocatalyst for CO oxidation under wide working conditions.

Author

Chen, Jie, Huang, Jianhui, Zeng, Jianpeng, Zheng, Fengying, and Li, Shunxing

Subjects
GOLD catalysts, NANOPARTICLES, GOLD nanoparticles, HETEROGENEOUS catalysts, FENCES, FUEL cells
Abstract

A supported gold catalyst was regarded as one of the most critical heterogeneous catalysts for CO oxidation in auto-emission and fuel cells, but it suffered bottlenecks in achieving high activity and stability under different conditions. Herein, a CeOx fence with a particular structure was successfully synthesized around Au nanoparticles dispersed in various supports by an auto-redox strategy. The dual-functional properties of this CeOx fence showed that it can not only enhance the activation of oxygen and activity of CO oxidation, but also stabilize Au nanoparticles in severe conditions. The optimal catalyst showed no deactivation after 100 hours of catalytic reaction at a temperature lower than 20 °C, and maintained high catalytic performance even after three rounds of thermal calcination at 800 °C. This work provides insights into the large-scale synthesis of supported gold catalysts with both superior activity and excellent stability in industrial applications. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

41. Urchin-like, Surface-Positively Charged, Double-Shelled SnS2@TiO2for Protecting and Enhancing Adsorption and Photocatalytic Activity to Remove High Concentrations of Anionic Pollutants

Author

Zheng, Jingyin, Yang, Hui, Zheng, Fengying, Liu, Fengjiao, Lin, Luxiu, and Li, Shunxing

Abstract

The application of a TiO2-based photocatalyst is puzzled by the poisoning from photodegradation intermediates and poor affinity between TiO2and target pollutants. Such obstacles could be overcome by adjustment of physicochemical properties, e.g., SnS2@TiO2with a new hollow urchin-like structure and positive charges on the outer shell, which is then used to remove high concentrations of anionic pollutants, including methyl orange (50 mg L–1, organic pollutant model) or potassium dichromate (250 mg L–1, heavy metal model). The adsorption performance under dark conditions and the photocatalytic activity for methyl orange or photoreduction of Cr(VI) under visible-light irradiation (λ > 420 nm) are in the order of hollow urchin-like SnS2@TiO2> SnS2> TiO2hollow spheres. The photocatalytic activity of hollow urchin-like SnS2@TiO2is one of the best among the TiO2/SnS2-based photocatalysts with different morphologies. These results may be due to the large surface area, the long light route in the photocatalyst, quick transfer of electrons in the heterostructure, the strong redox ability of TiO2, the wide visible-light absorption range with SnS2, and their synergistic effect. Impressively, by electrostatic attraction, anionic pollutants are selectively enriched onto the positively charged SnS2shell and photodegraded, and their intermediates are excluded from the inner TiO2shell, i.e., the poisoning on TiO2is avoided.

Published
2022
Full Text
View/download PDF

43. Multiwalled Carbon Nanotubes/CsPbX3@Polyacrylonitrile Core/Shell Nanofibers with Ultrahigh Water, Thermal, and Ultraviolet Stability.

Author

Huang, Yongjun, Wang, Tingting, Zheng, Jianzhong, Li, Feiming, Lan, Wangrong, Zheng, Fengying, and Li, Shunxing

Subjects
CARBON nanotubes, MULTIWALLED carbon nanotubes, NANOFIBERS, VISIBLE spectra, SPECIFIC heat, ELECTRIC conductivity
Abstract

The application of all‐inorganic perovskite nanocrystals (PNCs) is considerably limited by their inherent instability under the ubiquitous environmental conditions with high water content, temperature, and UV intensity. The multiwalled carbon nanotubes (CNTs) are combined with polyacrylonitrile (PAN) for the first time to improve the uniform luminous performance and environmental stability of PNCs, attributing to the dense growth of PNC via lead ions bound with rich carbonylation on CNT surfaces, the excellent characteristics of CNTs (including hydrophobicity, electrical conductivity, specific heat, UV absorption capacity), the weather resistance of PAN polymer, and their synergistic effect. Here, via one‐step single‐nozzle electrospinning at room temperature, CNTs, PNCs, and PAN are comprised as core–shell nanofibers (i.e., CNTs/PNCs@PAN) with tunable emissions between 472 and 683 nm, covering the visible light range from blue to red. The photoluminescence intensity of CNTs/CsPbBr3@PAN can be 93%, 91%, and 91% of the initial value, respectively, after being immersed in water for 20 days, heated to 90 °C, and exposed to 365 nm light irradiation for 48 h, which are superior to those of the previously reported PNCs/PAN fibers. The ultrahigh water stability is further proven by CNTs/PNCs@PAN‐based sensor for rhodamine 6G solution fluorescence detection. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

44. Hybrid multi-objective control allocation strategy for compound high-speed rotorcraft

Author

Zheng Fengying, Yuehua Chen, Chen Zhiming, Fengna Cheng, and Liu Longwu

Subjects
0209 industrial biotechnology, Mathematical optimization, Optimization problem, Computer science, Applied Mathematics, 020208 electrical & electronic engineering, Particle swarm optimization, 02 engineering and technology, Computer Science Applications, 020901 industrial engineering & automation, Control and Systems Engineering, 0202 electrical engineering, electronic engineering, information engineering, Redundancy (engineering), Control system design, Performance function, Electrical and Electronic Engineering, Instrumentation
Abstract

To address the problem of control surface redundancy for compound high-speed rotorcraft in multi-mode conversion process, a hybrid multi-objective control allocation strategy based on adaptive particle swarm optimization (PSO) algorithm is proposed. First, the control allocation problem is converted to a hybrid multi-objective optimization problem to solve the control redundancy, and a hybrid multi-objective optimization performance function is designed to satisfy the multiple requirements of flight mission. Second, a preference matrix is designed to determine the weight coefficients of the optimization performance function. The preference matrix can simplify the complexity of hybrid multi-objective optimization problem. Finally, an adaptive PSO algorithm is designed to solve the hybrid multi-objective control allocation dynamically. The simulation verifies the feasibility and effectiveness of the control allocation strategy, which eliminates the need of extra controllers in the mode conversion, reduces the difficulty of flight control system design and improves the system security.

Published
2019

47. Diversity, distribution and conservation of Chinese seagrass species

Author

Qiu Guanglong, Fan Hangqing, Zheng Fengying, and Zhang Wei

Subjects
Ecology, biology, Biodiversity, Species diversity, biology.organism_classification, Ecosystem services, Seagrass, Herbarium, Spatial ecology, Ecosystem, Posidonia australis, Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation
Abstract

Seagrass beds are one of the most productive ecosystems on Earth and an important source of ecosystem services. Accurate mapping of spatial patterns of seagrass species diversity are lacking at the na- tional scale in China, while taxonomic information on Chinese seagrass species requires an urgent update. This lack of information hinders national conservation and restoration programs for seagrass biodiversity. In this article we review studies of diversity, distributions and degradation of seagrass in China. A total of 22 seagrass species distributed along China's coastal regions belong to ten genera and four families, and account for about 30% of known seagrass species worldwide. A check of herbarium material stored in Sun Yat-sen University showed that the seagrass species previously identified as Posidonia australis in Hainan is in fact

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results