Search

Your search keyword '"Zhang, Yongfa"' showing total 530 results
Start Over Author "Zhang, Yongfa"
530 results on '"Zhang, Yongfa"'

3. Hydraulic Fracturing and Rock Mechanics

Author

Zhao, Yu, Zhang, Yongfa, and He, Pengfei

Subjects
Hydraulic fracturing, Fracture initiation, Fluid pressure, Natural fracture, Complex fracture network, Theoretical modeling, bic Book Industry Communication::R Earth sciences, geography, environment, planning::RB Earth sciences, bic Book Industry Communication::T Technology, engineering, agriculture::TG Mechanical engineering & materials::TGB Mechanical engineering
Abstract

This open access book is the first to consider the effect of non-uniform fluid pressure in hydraulic fractures. The book covers the key topics in the process of hydraulic fracture nucleation, growth, interaction and fracture network formation. Laboratory experiments and theoretical modeling are combined to elucidate the formation mechanism of complex fracture networks. This book is suitable for master’s/Ph.D. students, scientists and engineers majoring in rock mechanics and petroleum engineering who need to use a more reliable model to predict fracture behavior.

Published
2023
Full Text
View/download PDF

6. Experimental study on vacuum membrane distillation system of hollow fiber coupled with mechanical vapor recompression

Author

DENG Long, SI Zetian, LI Zhuohao, and ZHANG Yongfa

Subjects
mechanical vapor recompression, hollow fiber, vacuum membrane distillation, freshwater production ratio, separation efficiency, specific heating energy consumption, Environmental technology. Sanitary engineering, TD1-1066
Abstract

In order to solve the problems of low separation efficiency and high energy consumption in the industrial wastewater treatment, a combined system of mechanical vapor recompression and hollow fiber vacuum membrane distillation was constructed. The operational characteristics of the coupled system were investigated, and experimental studies were conducted on the evaporation of ammonium chloride solution under different feed conditions and long-term operation. The results indicated that as ammonium chloride mass concentration, feed temperature, feed flow rate and vacuum side pressure were 5%, 75 ℃, 10 m3/h and 24 kPa, the freshwater production ratio, freshwater conductivity, separation efficiency and specific heating energy consumption(SHEC) were obtained as 45.9 kg/h, 11.9 μS/cm, 99.9% and 118.5 kW·h/t. In addition, the increase of ammonium chloride mass concentration decreased the freshwater production ratio and increased the SHEC, while the increase of feed temperature and feed flow rate increased the freshwater production ratio and decreased the SHEC. After 240 h of long term operation, membrane fouling did not significantly affect the freshwater quality, but reduced the freshwater production ratio. The water production rate was restored to 96.1% of the original through membrane cleaning. The system can separate the ammonia chloride solution with high efficiency and has a broad application prospect.

Published
2024
Full Text
View/download PDF

16. Introduction

Author

Zhao, Yu, Zhang, Yongfa, He, Pengfei, Zhao, Yu, Zhang, Yongfa, and He, Pengfei

Published
2023
Full Text
View/download PDF

20. Influence of competition-outcome feedback in video games on players' flow experience

Author

Zhang, Yongfa, Liang, Qiongdan, and Wang, Fei

Subjects
Flow (Psychology) -- Research, Video games -- Psychological aspects, Psychological research, Feedback (Psychology) -- Psychological aspects, Competition (Psychology) -- Research, Psychology and mental health
Abstract

Competition is a fundamental feature of video games. However, the influence of competition-outcome feedback on players' flow experience is not clearly understood. This study aims to examine this effect and explore its mechanisms and boundaries. In the experiment, 108 male participants were randomly assigned to one of three groups (based on the condition of receiving winning feedback, losing feedback, and no feedback) in competitive video game playing. The results showed that receiving continuous winning feedback enhanced the players' flow experience, while receiving losing feedback impaired the players' flow experience. In addition, moderated mediation model analysis revealed that the relative effect of receiving winning feedback was mediated by anxiety that was further moderated by trait competitiveness. Only in those with high trait competitiveness can receiving winning feedback relieve their anxiety and facilitate the flow experience in turn. These results develop our understanding of the role of competition in video games and provide insights into video game design., Author(s): Yongfa Zhang [sup.1] , Qiongdan Liang [sup.1] , Fei Wang [sup.1] [sup.2] Author Affiliations: (1) grid.12527.33, 0000 0001 0662 3178, Department of Psychology, School of Social Sciences, Tsinghua University, [...]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results