Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and ...Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.展开更多
According to the special requirements of secondary mining of resources in gateway-and-pillar goal in extra-thick seams of Shanxi, this paper presents a technical proposal of back stoping from level floors. Numerical s...According to the special requirements of secondary mining of resources in gateway-and-pillar goal in extra-thick seams of Shanxi, this paper presents a technical proposal of back stoping from level floors. Numerical simulation and theoretical analysis are ccsed to investigate the compaction characteristics of cavities under stress as well as an appropriate mining height of the primary-mining layer based on dif- ferent mining widths and pillar widths. For Yangjian coal mine, the mining thickness of the first seam during back stoping from level floor is determined to be 3 m, which meets the relevant requirements. Gateway-and-pillar goaf of a single layer has a range of influence of 9 m vertically. If gateway-and-pillar goaf occurs both in 9-1 and 9-5 layers, the range is extended to within 11.2 m. When the mining width of a gateway is less than 2 m or larger than 5 m, the gateway-and-pillar goal in the upper layer of the primary-mining seam can be filled in and compacted after stoping. When the working face is 2 m away from the gateway and pillar before entering into it and after passing through it, the coal body under the gateway and pillar is subjected to relatively high stress. During mining of the upper layer, moreover, the working face should interlock the goaf in primary-mining layer for 20 m.展开更多
With the constant advance of global urbanization and aggravation of urban construction land scarcity,high-rise residential buildings have become one of the main carriers of urban residential function on account of bot...With the constant advance of global urbanization and aggravation of urban construction land scarcity,high-rise residential buildings have become one of the main carriers of urban residential function on account of both land saving and large housing requirement.However,relevant studies on consumers' floor selection preference in high-rise residential buildings,regarding what inherent and regular features and causes it has,are still insufficient,despite that related issues have important practical significance for real estate developers and designers' decision making in terms of dwelling size ratio,floor area,indoor layout,and so on.This study,based on systematic examination of existing domestic and international researches,seeks to make empirical tests and generalization on the above issues from the aspect of "utility function"(safety,comfortableness,accessibility and economic efficiency) of the living environment that impacted by different floor levels,and floor selection features regarding consumers' social and family structure attributes,as well as the intrinsic correlation between them.The results show the existence of floor level preference in high-rise residential buildings.Its essence is a personalized characterization of consumers' social and family structures' attributes in selecting the "utility function" of the living environment,as the preference value differs under various attributes including gender,age,income,family members and others.展开更多
基金Project supported by Ministry of Land, Infrastructure, Transport and Tourism of Japan Project(DUT10RC(3)103) supported by the Fundamental Research Funds for the Central Universities in China+2 种基金 Project(20111027) supported by the Liaoning Provincial Scientific Research Foundation, China Key Project (2012BAJ02B05) supported by the Twelfth Five-Year National Technology Program of China Project supported by Dalian Municipal Construction Technology Program, China
文摘Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.
基金Financial support for this work was provided by the National High-Tech Research and Development Program of China (No. 2012AA062101)the Priority Academic Development Program of Jiangsu Higher Education Institutions (No. SZBF2011-6-B35)the Graduate Students Innovation Fund of Colleges and Universities in Jiangsu Province (No. CXZZ12_0950)
文摘According to the special requirements of secondary mining of resources in gateway-and-pillar goal in extra-thick seams of Shanxi, this paper presents a technical proposal of back stoping from level floors. Numerical simulation and theoretical analysis are ccsed to investigate the compaction characteristics of cavities under stress as well as an appropriate mining height of the primary-mining layer based on dif- ferent mining widths and pillar widths. For Yangjian coal mine, the mining thickness of the first seam during back stoping from level floor is determined to be 3 m, which meets the relevant requirements. Gateway-and-pillar goaf of a single layer has a range of influence of 9 m vertically. If gateway-and-pillar goaf occurs both in 9-1 and 9-5 layers, the range is extended to within 11.2 m. When the mining width of a gateway is less than 2 m or larger than 5 m, the gateway-and-pillar goal in the upper layer of the primary-mining seam can be filled in and compacted after stoping. When the working face is 2 m away from the gateway and pillar before entering into it and after passing through it, the coal body under the gateway and pillar is subjected to relatively high stress. During mining of the upper layer, moreover, the working face should interlock the goaf in primary-mining layer for 20 m.
基金supported by National Natural Science Foundation of China(41501173)Postdoctoral Science Foundation of China(2015M571418)Central University Basic Research and Operating Expenses of Special Funding(HIT.NSRIF.201656)
文摘With the constant advance of global urbanization and aggravation of urban construction land scarcity,high-rise residential buildings have become one of the main carriers of urban residential function on account of both land saving and large housing requirement.However,relevant studies on consumers' floor selection preference in high-rise residential buildings,regarding what inherent and regular features and causes it has,are still insufficient,despite that related issues have important practical significance for real estate developers and designers' decision making in terms of dwelling size ratio,floor area,indoor layout,and so on.This study,based on systematic examination of existing domestic and international researches,seeks to make empirical tests and generalization on the above issues from the aspect of "utility function"(safety,comfortableness,accessibility and economic efficiency) of the living environment that impacted by different floor levels,and floor selection features regarding consumers' social and family structure attributes,as well as the intrinsic correlation between them.The results show the existence of floor level preference in high-rise residential buildings.Its essence is a personalized characterization of consumers' social and family structures' attributes in selecting the "utility function" of the living environment,as the preference value differs under various attributes including gender,age,income,family members and others.
