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With the continuous increase of coal seam mining depth, the coal mine production faced with complex water inrush mechanism and changeable main controlling factors, which makes the prediction of floor water inrush more difficult. In order to accurately predict the risk of floor water inrush, the vulnerability index method was used to obtain the risk weight of floor water inrush for each sub-factor, and the analytic hierarchy process(AHP) was used to divide the risk threshold of floor water inrush, so as to establish coal seam floor water inrush prediction model. We analyzed the geological and hydro-geological data of Henan Longmen Coal Industry Changcun Coal Mine from the three aspects of water inrush sources, water inrush channels and aquifers, the influencing factors of floor water inrush are divided into eight factors: aquifer water pressure, water output, grouting volume, fault similarity dimension, fault dip, fault strike, fault drop and effective aquifer thickness. Based on eight sub-factors, the risk of floor water inrush is divided into five areas: safe area [0.25, 0.32), relatively safe area [0.32, 0.44), the more dangerous area [0.44, 0.56), the dangerous area [0.56, 0.70), and the extremely dangerous area [0.70, 0.85]. Finally, the vulnerability index method evaluation model based on AHP was established. Compared with the traditional water inrush coefficient method, the evaluation results of the vulnerability index method based on AHP have better accuracy, and the division is more refined and reasonable, which provides a scientific evaluation method and theoretical basis for the prediction of mine water hazards.

With the continuous development of YQ2 Wellblock, it is estimated that there will be about 65.42% of gas wells whose wellhead pressure cannot reach the required inlet pressure within two years, and then, the wellblock cannot be maintained at stable production. Thus, it is urgent to conduct the research on optimization of supercharged gathering scheme. Herein, 5 supercharged gathering schemes were developed based on the different locations and quantity of supercharging equipment, which were determined according to the Benedict-Webb-Rubin-Starling(BWRS) Equation and the Fourth Order Runge-Kutta Method, through the analysis on change laws of oil/casing pressure in 309 wells and the prediction of supercharging time. Then, comparison was made among the 5 supercharged gathering schemes through fuzzy evaluation using the two primary evaluation indicators of technical economy and safety, refining the seven secondary evaluation indicators, such as the wellhead abandonment pressure, pressure loss of pipeline network and total investment,and determining their weights with the Analytic Hierarchy Process(AHP) method. Finally, it was determined to adopt the scheme of centralized supercharging at the terminal station + regional supercharging at 12 stations. In general, the research results are of great significance to the efficient development of gas field, cost reducing and benefit increasing, effective reduction of wellhead abandonment pressure, and the maximization of effectiveness of supercharging equipment for stable production.

Data centers are important infrastructure in China, with constantly increasing industry size, market revenues, and electricity consumption. The major cooling systems of data centers currently in operation in China are air-cooled, with a low energy utilization rate and great potentials for energy saving. Therefore, it is imperative to develop novel cooling technologies for green and energyefficient data centers. The cooling technology needs to solve two problems. First, as equipment heat production increases, the cooling capacity of the cooling system needs to be improved to match heat production and transfer rates. Second, to address the low energy efficiency problem, green and energy-efficient cooling technologies with industrial application prospects need to be developed. This study reviews the development status of data center cooling methods and categorizes cooling technologies into air conditioner cooling, fresh air cooling, indirect cooling, direct single-phase liquid cooling, and direct two-phase liquid cooling. We analyze the development trends of cooling technologies and suggest that green and high-efficient data centers should focus on the improvement in the efficiency of cooling systems, optimizations of hot and cold fluid channels, applications of new liquid cooling materials, and promotion of heat recovery systems. Furthermore, we propose suggestions for the stable and orderly development of the data center industry from the aspects of optimizing top-level design, developing key technologies, formulating scientific standards, improving industrial layout, and focusing on energy structure.

A numerical model was developed on the diffusion, migration and concentration distribution of exhausts and particles in atmospheric wind field at Antarctica. The characteristics of diffusion, migration and concentration distribution of exhausts and particles generated by fuel engine was studied using computational fluid dynamics combined with particle dynamics and DSMC (direct simulation Monte Carlo) method. The results show that the mass concentration of NO2 and exhaust temperature decrease rapidly near the exhaust pipe, while the exhaust diffusion decrease slowly away from the exhaust pipe. The collision and cohesion reduces the concentration of the particles in atmospheric wind field, with the reduction of the influence region by the diffusion of particles in the atmospheric environment It increases the mass concentration of particles in each location by the increase of mass flow rate and initial size of the particles and the decrease of the atmospheric wind velocity. Althrough the influence radius varies with the particle flow rate, initial size and wind velocity, the mass concentration of particles meets the national standard at the distance of about 40 m away from the particle diffusion source. [ABSTRACT FROM AUTHOR]

Synovial sarcoma is a malignant soft tissue with unknown origin. Although head and neck region is the second common site of involvement, rare cases have been reported in Para nasal sinus and larynx. We presented two cases of synovial sarcoma, one of which arised from maxillary sinus and the other from laryx, and re- view the literature to sum up the diagnosis and treatment strategies. The conclusion is that synovial sarcoma in the head and neck still raises diagnostic and therapeutic issues. Surgical excision with wide margins is essential and necessary, usually associated radiotherapy. The effect of chemotherapy remains to explored.

To optimize the configuration of the conventional SE and FSE sequence parameters in low field MRI. With the combination of larger vision, relatively thinner slice thickness, small number of excitation (NEX = 1 or 2), the signal-to-noise ration and the spatial resolution on follow-up images are moderate, the scan time is significantly shorter along with fewer motion artifacts, the check success rate is improved.