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In China, the equal accessibility of social infrastructure, especially public housing and healthcare, has become a prominent concern in solving the problems of rapid but uneven growth-oriented urbanization in the post-reform era. However, few studies have focused on the accessibility of various healthcare resources to different types of public housing using different transport modes. Utilizing Internet map services, this study first calculated the travel time from talent, economically affordable, and public rental housing to hospitals using three transport modes—walking, public transport, and driving—in Shenzhen, China. Subsequently, the optimized two-step floating catchment area method (2SFCA) was employed to comprehensively evaluate the accessibility of healthcare resources to public housing and explore differences in healthcare accessibility among different populations. The results reveal that: (1) Public housing is located far away from healthcare resources, with 15% of public housing unable to access AAA hospitals within 30 minutes by car, and only 10% able to access ordinary hospitals within 15 minutes. (2) Accessibility of healthcare resources to public housing exhibits spatial heterogeneity, gradually declining from special to non-special economic zones. (3) Talent housing experiences the best accessibility, followed by affordable and public rental housing. (4) Public transportation and walking exhibit greater spatial variation in accessibility than driving. Theoretically, the current public housing accessibility in Shenzhen reflects the common problems of public housing accessibility throughout the country. In the process of promoting the equal accessibility of basic public services, focus on its accessibility should be emphasized. This study proposes an optimized 2SFCA by introducing a Gaussian distance decay function, establishing a multilevel search radius, considering supply and demand-side competition effects, and using real-time traffic big data. Our methodological framework simultaneously considers differences among various types of public housing, hospitals with different service capacities, and diverse travel modes. This provides a new research perspective for a comprehensive and thorough understanding of the equal accessibility of basic public services.

In view of the problem that the physical simulation model of gas extraction is too large to use large size raw coal for experiment, the preparation of briquette is studied. In order to make briquette and raw coal as close as possible in gas adsorption and permeability, the effects of sodium humate, carboxymethyl cellulose, sodium bentonite, polyvinyl acetate emulsion and coal tar as cementing agent on briquette adsorption and permeability are studied. Based on the consideration of pulverized coal production cost and workload, five different pulverized coal particle size distribution schemes are designed according to Horsfield filling theory, dense packing experience, and Fuller dense packing curve, and the influence of different schemes on briquette permeability is studied. The results show that: sodium humate should be used as cementing agent for comprehensive consideration of adsorbability and permeability; the particle size distribution of pulverized coal has a significant effect on the permeability of briquettes. In order to reduce the cost and workload of pulverized coal production, an appropriate pulverized coal particle size distribution scheme should be selected according to the experimental needs.

In order to obtain the dust distribution of PM5 and PM10 in large mining height fully-mechanized face, the dust concentration around the shearer drum and along the downwind side of the shearer are measured under the conditions of the following wind and upwind respectively. The results show that when coal is cut in following wind, the initial concentration of PM5 and PM10 dust around the rear drum is high, then gradually decreases and becomes stable. The concentration of the front drum is low at first, and rises sharply after 70 to 80 s. When coal is cut in upwind, the initial concentration of the front drum fluctuates greatly, and the concentration of the rear drum rises about 10 s earlier than that in following wind. When coal is cut in following wind, the PM5, PM10 and total coal dust concentration reach the highest at the downwind of shearer around 10 m, then gradually reduce and tend to be stable at 40 m. The PM5 proportion is higher at first, and falls to the lowest at about 15 m, then rises again under the effect of wind. The PM10 proportion is on the decline overall. When coal is cut in upwind, the dust concentration reaches the highest at the downwind of shearer 6 m or so, and is stable about 20 m. PM5 accounts for 60% to 80%, while PM10 accounts for 65% to 95% under both conditions.