Search

Your search keyword '"Hu, Zhifang"' showing total 139 results
Start Over Author "Hu, Zhifang"
139 results on '"Hu, Zhifang"'

9. Developmental Trajectories of Childhood Emotional Maltreatment and Smartphone Addiction in Primary School Children: Based on a Three-Year Longitudinal Study.

Author

Hu, Zhifang, Li, Xiaojun, and Xiang, Yanhui

Subjects
*COMPULSIVE behavior, *RISK assessment, *SMARTPHONES, *ELEMENTARY schools, *RESEARCH funding, *CHILD abuse, *SEX distribution, *AGE distribution, *DESCRIPTIVE statistics, *LONGITUDINAL method, *CHILD development, *PSYCHOLOGICAL abuse, *SCHOOL children, *SOCIAL support, *COUNSELING, *CHILDREN, RISK factors
Abstract

Primary school children are in a critical period of growth, and childhood emotional maltreatment (CEM) can have a tremendous negative impact, leading to smartphone addiction (SPA). Considering developmental trajectories has significant implications for understanding the relationship between CEM and SPA. This study was conducted with 208 Chinese primary school children to investigate the developmental trajectories of SPA and CEM during children's development, the relationship between the two developmental trajectories, and the influence of gender on the two developmental trajectories through a three-year, three-wave longitudinal study. The study found a linear increase with age in both SPA and CEM in primary school children. Further, the initial level of SPA was significantly higher in boys than girls. Finally, the developmental trajectory of CEM positively predicted the developmental trajectory of SPA. This study contributes to understanding the developmental trajectory of SPA and CEM in the child population. It provides theoretical support and practical guidance for preventing and intervening SPA in children from the perspective of the family environment. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

14. Regional gas control scheme and effect analysis

Author

HU Zhifang

Subjects
coal mining, deep mining, stress concentration, regional gas control, gas outburst elimination, covering excavating in coal roadway, crossing boreholes, hydraulic punching, Mining engineering. Metallurgy, TN1-997
Abstract

In view of problems of high gas pressure and poor permeability of outburst coal seam, unsatisfactory of outburst elimination effect of regional gas control, slow speed of coal roadway excavation and tension of working face replacement caused by deep mining on 15-17220 working face in the Twelfth Coal Mine of Pingdingshan Tia'an Coal Mining Co., Ltd., a regional gas control scheme of 'crossing boreholes + hydraulic punching' was proposed, and the regional gas control effect was tested and verified. The following conclusions are obtained: residual gas content and pressure are reduced to 5.57 m3/t and 0.40 MPa, they are lower than threshold of outburst prevention regulation, which achieve outburst prevention standard for coal mine safety mining; drilling cuttings and borehole gas emission initial velocity respectively are reduced to 3.5 kg/m and 2.18 L/min, the indicators are not overweight, so as to eliminate outburst danger of coal seam; coal roadway excavation footage is risen every month steady with 10%, and effectively relieves problem of tension of working face replacement. The control results validate rationality of the regional gas control scheme.

Published
2018
Full Text
View/download PDF

26. Geological characteristics and co-exploration and co-production methods of Upper Permian Longtan coal measure gas in Yangmeishu Syncline, Western Guizhou Province, China

Author

Fu-guo Wang, Yan-sheng Shan, Yuan Yuan, Jia-qiang Zhang, Tang Yue, Hu Zhifang, Huan-peng Chi, Cai-qin Bi, and Ya-ran Liu

Subjects
Coalbed methane, business.industry, Fossil fuel, technology, industry, and agriculture, Coal mining, Paleontology, Geology, Coal measures, respiratory system, Geotechnical Engineering and Engineering Geology, Oceanography, complex mixtures, respiratory tract diseases, Hydraulic fracturing, Mining engineering, Geochemistry and Petrology, Natural gas, otorhinolaryngologic diseases, Geological survey, Economic Geology, Coal, Computers in Earth Sciences, business, Earth-Surface Processes
Abstract

Coal measure gas (also known as coal-bearing unconventional gas) is the key field and development direction of unconventional natural gas in recent years. The exploration and evaluation of coal measure gas (coalbed methane, coal shale gas and coal measure tight sandstone gas) from single coalbed methane has greatly expanded the field and space of resource evaluation, which is of positive significance for realizing the comprehensive utilization of coal resources, maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development. For the first time, in Yangmeishu Syncline of Western Guizhou Province, the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation, identified the geological conditions of coal measure gas and found high quality resources. The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×109 m3/km2. In this area, the coal measures are characterized by many layers of minable coal seams, large total thickness, thin to the medium thickness of the single layer, good gas-bearing property of coal seams and coal measure mudstone and sandstone, good reservoir physical property and high-pressure coefficient. According to the principle of combination of high quality and similarity of key parameters of the coal reservoir, the most favorable intervals are No.5−2, No.7 and No.13−2 coal seam in Well YMC1. And the pilot tests are carried out on coal seams and roof silty mudstone, such as staged perforation, increasing hydraulic fracturing scale and “three gas” production. The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained, which has realized the breakthrough in the geological survey of coal measure gas in Southwest China. Based on the above investigation results, the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the co-exploration and co-production methods, such as the optimization method of favorable intervals, the high-efficiency fracturing and reservoir reconstruction method of coal measures, and the “three gas” drainage and production system, are systematically summarized in this paper. It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.

Published
2020

41. Technological conditions for purification of hafnium by iodide process

Author

Hong-Lin Jiang, Zhong-Qi Li, Hu Zhifang, Li-Jun Wang, Tian Lisen, and Yan-Xi Yin

Subjects
chemistry.chemical_classification, Materials science, Control rod, Inorganic chemistry, Iodide, Metals and Alloys, chemistry.chemical_element, Condensed Matter Physics, Retort, law.invention, Hafnium, Crystal, chemistry, Impurity, law, Scientific method, Materials Chemistry, Physical and Theoretical Chemistry, Bar (unit)
Abstract

In nuclear industry, the purity of hafnium control rod is usually significant, and the process parameters will affect the impurity contents. In this study, the four key factors (filament temperature, retort materials, feeds, and iodide reaction time) were investigated. It is found that the impurity contents of Fe, Ni in the hafnium crystal bar decrease with the K value rising. Both the retort materials and feed types have obvious influence on the impurity contents of hafnium crystal bar. The iodide reaction time has little effect on the impurity contents of hafnium crystal bar.

Published
2014

42. Deposition rate of hafnium crystal bar by iodide process

Author

Zhong-Qi Li, Tian Lisen, Li-Jun Wang, Yan-Xi Yin, Hong-Lin Jiang, and Hu Zhifang

Subjects
chemistry.chemical_classification, Range (particle radiation), Materials science, Temperature control, Iodide, Inorganic chemistry, Metals and Alloys, Analytical chemistry, chemistry.chemical_element, Condensed Matter Physics, Hafnium, Crystal, chemistry, Molybdenum, Materials Chemistry, Physical and Theoretical Chemistry, Deposition (chemistry), Bar (unit)
Abstract

Single variable and deposition weight methods were adopted in the experiment. The hafnium crystal bar was fabricated by the iodide process. Influence of hafnium filament temperature (K value), temperature controlling method, types of feed, and the loading methods on the deposition rate were studied. The results show that the K value, temperature control method, types of feed, and the loading methods have obvious effects on the deposition rate of the hafnium crystal bar. The deposition rate increases with the K value rising in the range of certain temperature; the salt bath controlling temperature method could effectively obtain the better deposition rate; the greater the contact areas of the feeds are, the faster the deposition rate is. So, the optimal iodide deposition techniques of preparing hafnium crystal bar are as follows: hafnium turnings as feed, molybdenum feed retainer charging, salt bath temperature controlling under the higher K value.

Published
2014

49. Ultrafast All-Optical Graphene Modulator

Author

Li, Wei, primary, Chen, Bigeng, additional, Meng, Chao, additional, Fang, Wei, additional, Xiao, Yao, additional, Li, Xiyuan, additional, Hu, Zhifang, additional, Xu, Yingxin, additional, Tong, Limin, additional, Wang, Hongqing, additional, Liu, Weitao, additional, Bao, Jiming, additional, and Shen, Y. Ron, additional

Published
2014
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results