Search

Your search keyword '"Zhai, Wenbo"' showing total 111 results
Start Over Author "Zhai, Wenbo"
111 results on '"Zhai, Wenbo"'

7. The seepage model for CO2 in Shale considering dynamic slippage, effective stress and gas adsorption.

Author

Zhai, WenBo, Wu, Di, Liu, XueYing, Xiao, XiaoChun, Ding, Xin, Miao, Feng, and Chen, XinTong

Subjects
GAS dynamics, EFFECTIVE stress (Soil mechanics), GAS absorption & adsorption, REAL gases, SHALE
Abstract

This paper first conducted a shale injection CO2 seepage experiment based on an improved single-vessel pressure pulse attenuation method. The experimental results reveal that the evolution pattern of shale permeability with respect to pore pressure can be divided into before and after phase change. The overall trend is that it first decreases and then increases, which is not a simple exponential form. The exponential fit of the permeability before and after the phase change alone is one-sided. A CO2 adsorption deformation test was subsequently conducted on shale under the same temperature and gas pressure conditions. The results revealed that with increasing CO2 pressure, the expansion and deformation of shale first increased but then decreased. The entire deformation process involves three deformation stages: a short compression stage, a slow expansion stage, and a stable deformation stage. The slip effect was corrected by combining adsorption expansion, effective stress, the real gas effect and the dynamic slip factor. The modified permeability model is more consistent with the relationship between permeability and pore pressure. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

10. Solar‐Driven Lithium Extraction by a Floating Felt

Author

Chen, Xin, primary, Yu, Wenhua, additional, Zhang, Yue, additional, Huang, Chen, additional, Nie, Lu, additional, Yu, Jiameng, additional, Zhang, Yuyao, additional, Zhang, Chang, additional, Zhai, Wenbo, additional, Zhang, Xinshui, additional, Yu, Yi, additional, and Liu, Wei, additional

Published
2024
Full Text
View/download PDF

19. Multilayer Adsorption Characteristics of CO2in Organic Nanopores with Different Pore Sizes: Molecular Simulation and Ono–Kondo Lattice Model

Author

Chen, Xintong, Wu, Di, Miao, Feng, Xiao, Xiaochun, Liu, Xueying, and Zhai, Wenbo

Abstract

Shale contains numerous organic micropores with significant potential for CO2storage. To precisely evaluate the CO2storage potential of shale reservoirs, it is essential to accurately quantify the adsorption of CO2within these pores. This study used Grand Canonical Monte Carlo (GCMC) molecular simulations to analyze the CO2adsorption behavior in organic micropores of varying sizes. The study clarified the number and width of the CO2adsorption layers in micropores of various sizes and proposed a method for segmenting the multilayer adsorption structure. Additionally, the classic Ono–Kondo lattice (OK) model was extended to characterize pore-filling adsorption, incorporating solid–gas and gas–gas interactions. Accurate characterization of CO2multilayer adsorption and precise calculation of CO2absolute adsorption in micropores were achieved. Results indicate that CO2exhibits pore-filling adsorption behavior in organic micropores, forming a multilayer adsorption structure governed by the pore size. Following symmetry principles, the adsorption layer structure in organic micropores can be simplified to a maximum of three layers. When only one adsorption layer forms, its width equals the gas-accessible pore size. For two or more layers, the width of the original layer stabilizes as additional layers form. The stable adsorption layer widths, from nearest to farthest from the pore wall, are 0.33, 0.45, and 0.39 nm. The improved OK model accurately describes CO2excess and absolute adsorption isotherms across different pore sizes and calculates the CO2density in each adsorption layer, showing high consistency with GCMC simulation results. These findings highlight the importance of understanding the CO2multilayer adsorption structure for accurately estimating CO2adsorption in organic micropores.

Published
2024
Full Text
View/download PDF

45. FEM thermal analysis of high power GaN-on-diamond HEMTs

Author

Xun Hou, Jingwen Zhang, Zhai Wenbo, Hong-Xing Wang, Bu Ren'an, and Chen Xudong

Subjects
010302 applied physics, Materials science, business.industry, Diamond, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Isothermal process, Finite element method, Electronic, Optical and Magnetic Materials, Thermal conductivity, 0103 physical sciences, Thermal, Heat spreader, Materials Chemistry, engineering, Optoelectronics, Electrical and Electronic Engineering, 0210 nano-technology, business, Thermal analysis, Saturation (magnetic)
Abstract

A three-dimensional thermal analysis of GaN HEMTs on diamond substrate is investigated using the finite element method. The diamond substrate thickness, area and shape, transition layer thickness and thermal conductivity of the transition layer are considered and treated appropriately in the numerical simulation. The temperature distribution and heat spreading paths are investigated under different conditions and the results indicate that the existence of the transition layer causes an increase in the channel temperature and the thickness, area and shape of the diamond substrate have certain impacts on the channel temperature too. Channel temperature reduces with increasing diamond substrate thickness and area but with a decreasing trend, which can be explained by the saturation effects of the diamond substrate. The shape of diamond substrate also affects the temperature performance of GaN HEMTs, therefore, to achieve a favorable heat dissipation effect with the settled diamond substrate area, the shape should contain as many isothermal curves as possible when the isothermal gradient is constant. The study of the thermal properties of GaN on diamond substrate is useful for the prediction of heating of high power GaN HEMTs devices and optimal designs of an efficient heat spreader for GaN HEMTs.

Published
2018
Full Text
View/download PDF

47. FEM thermal and stress analysis of bonded GaN-on-diamond substrate

Author

Xun Hou, Hong-Xing Wang, Bu Ren'an, Zhai Wenbo, Jingwen Zhang, and Chen Xudong

Subjects
010302 applied physics, Materials science, Computer simulation, General Physics and Astronomy, Diamond, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, 01 natural sciences, Finite element method, lcsh:QC1-999, Stress (mechanics), Diamond substrate, Thermal conductivity, 0103 physical sciences, Thermal, engineering, Area ratio, Composite material, 0210 nano-technology, lcsh:Physics
Abstract

A three-dimensional thermal and stress analysis of bonded GaN on diamond substrate is investigated using finite element method. The transition layer thickness, thermal conductivity of transition layer, diamond substrate thickness and the area ratio of diamond and GaN are considered and treated appropriately in the numerical simulation. The maximum channel temperature of GaN is set as a constant value and its corresponding heat power densities under different conditions are calculated to evaluate the influences that the diamond substrate and transition layer have on GaN. The results indicate the existence of transition layer will result in a decrease in the heat power density and the thickness and area of diamond substrate have certain impact on the magnitude of channel temperature and stress distribution. Channel temperature reduces with increasing diamond thickness but with a decreasing trend. The stress is reduced by increasing diamond thickness and the area ratio of diamond and GaN. The study of mechanical and thermal properties of bonded GaN on diamond substrate is useful for optimal designs of efficient heat spreader for GaN HEMT.

Published
2017

48. Unraveling the Microstructure of Inorganic Halide Perovskites during Thermally Driven Phase Transition and Degradation

Author

Luo, Xin, Hao, Ruixin, Wang, Hao, Zhai, Wenbo, Wang, Zeyu, Ning, Zhijun, and Yu, Yi

Abstract

The microstructure of halide perovskites during thermally driven phase transition and degradation is difficult to probe because of their radiation-sensitive nature. Taking advantage of low dose in situ high-resolution transmission electron microscopy imaging, we directly observed the nucleation and growth process of the phase transition from orthorhombic γ-CsPbBr3to cubic α-CsPbBr3in nanoplates during heating. The normalization of (PbBr6)4–octahedra was observed, and phase transition pathways (edge-to-center growth and island growth) were summarized. Phase fluctuation/recovery occurs during the phase transition process. In addition, the thermal degradation caused by high temperature was investigated. Degradation occurs from the outer edge to the center region. This work provides a microscopic basis for the understanding of phase transition and its application in devices.

Published
2024
Full Text
View/download PDF

50. Enhancing UV-C Photoelectron Lifetimes for Avalanche-like Photocurrents in Carbon-Doped Bi3O4Cl Nanosheets

Author

Fu, Minghui, Dou, Hongbin, Zhai, Wenbo, Hou, Bingsen, Wu, Congcong, Meng, Wei, Wu, Nan, Zhang, Zhuo, Weng, Tsu-Chien, Yu, Yi, and Wang, Hung-Ta

Abstract

Interlayer electric fields in two-dimensional (2D) materials create photoelectron protecting barriers useful to mitigate electron–hole recombination. However, tuning the interlayer electric field remains challenging. Here, carbon-doped Bi3O4Cl (C:Bi3O4Cl) nanosheets are synthesized using a gas phase protocol, and n-type carriers are acquired as confirmed by the transconductance polarity of nanosheet field effect transistors. Thin C:Bi3O4Cl nanosheets show excellent 266 nm photodetector figures of merit, and an avalanche-like photocurrent is demonstrated. Decaying behaviors of photoelectrons pumped by a 266 nm laser pulse (266 nm photoelectrons) are observed using transient absorption spectroscopy, and a significant 266 nm photoelectron lifetime quality in C:Bi3O4Cl is presented. Built C:Bi3O4Cl models suggest that the interlayer electric field can be boosted by two different carbon substitutions at the inner and outer bismuth sites. This work reports a facile approach to increase the interlayer electric field in Bi3O4Cl for future UV-C photodetector applications.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results