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The pore structure has a significant impact on the capability of coal seams to adsorb methane. But there is currently limited research on the features of adsorption pore structure in high-rank coal and its influence on methane adsorption capability. Taking the high-rank coal samples from Nuodong Coal Mine of Guizhou Xing'an Coal Industry Co., Ltd. as the research object, low-temperature N2 adsorption and low-temperature CO2 adsorption experiments are conducted. Combined with fractal theory, this paper studies the pore structure features of high-rank coal adsorption pores. Through high-pressure isothermal methane adsorption experiments, the influence of coal reservoir properties, pore structure features, and fractal dimension on methane adsorption capability is analyzed. The results show the following points. ① The pore morphology of high-rank coal reservoirs is relatively simple, mostly consisting of parallel plate pores and narrow slit pores with open ends. Micro pores dominate the pore structure of coal, with pore volume and pore specific surface area accounting for more than 98%, providing space for gas enrichment. ② The method calculates the comprehensive fractal dimension of high-rank coal pores based on the proportion of pore volume in different aperture segments, with micropore fractal dimension dominating the comprehensive fractal dimension. The pore structure of coal samples has obvious fractal features and strong heterogeneity of pores. ③ The Langmuir model can describe the adsorption behavior of high-rank coal. The physical properties, pore structure, and fractal dimension of coal reservoirs have a significant impact on methane adsorption capability. Langmuir volume is linearly positively correlated with maximum vitrinite reflectance, vitrinite content, ash content, and moisture content. It is linearly negatively correlated with inertinite content. The Langmuir volume is linearly positively correlated with the pore specific surface area and pore volume of the adsorption pores. The Langmuir volume is weakly linearly correlated with the fractal dimension. The research results can provide theoretical guidance for the exploration and development of high-rank coalbed methane and the prevention and control of coal mine methane disasters in southwestern Guizhou.

To study the deformation and failure law of roadway surrounding rock with weak interlayer under dynamic and static loads, taking the deep transportation roadway of Longfeng Coal Mine as the research object, the mechanical deformation characteristics of roadway surrounding rock with weak interlayer under dynamic and static loads is analyzed by using FLAC3D numerical simulation software, and the support optimization scheme is proposed combined with the actual roadway situation on site. The results show that the influence of dynamic load on roadway both sides is greater than that of roadway roof and floor. Compared with the static load, the deformation and failure range of roadway surrounding rock under dynamic load is more sufficient, the weak interlayer is easier to separate from the adjacent rock stratum and a dangerous area with caving risk is formed in the roadway roof. The stability of surrounding rock is obviously improved under the new support measures, which ensures the safe production of the mine.

Objective: To investigate the maxillary sinus development and provide data for sinus surgery on children., Method: Two thousand two hundred and thirty-eight children were randomly selected among those who underwent skull and nasal sinus CT scanning because of certain symptoms and signs. Patients were divided into eighteen age cohorts based on their age at the time of the scan. Anterior-posterior, transverse diameters and vertical height of the maxillary sinus were measured and statistically analyzed., Result: The maxillary sinus volume was enlarging even in adult, hut the growth of maxillary sinus was relatively stable in adolescent. The difference of transverse and anterior-posterior diameters of maxillary sinus had no statistical significance between female and male (P > 0.05), while there was statistically significant difference in the vertical height of maxillary sinus (P < 0.05)., Conclusion: The results will aid the physicians when correlating the clinical and radiographic findings of pediatric patients who are being evaluated for sinus disease and potential surgical intervention.

Objective: To investigate the nasal sinus development and discuss the relation between sinusitis and nasal development., Method: One thousand seven hundred and five healthy children and 1424 children with sinusitis were selected randomly. All children underwent naso sinus computer tomography. Sagittal, coronal and transverse diameters of all sinuses were measured and statistically analyzed., Result: The measured sinus diameters of children with sinusitis were longer than that of healthy children (P < 0.01). Pearson analyses revealed a low correlation of age and the history of sinusitis (P < 0.01), and no correlation of gender and the history of sinusitis. There was moderate to high consistency between clinical diagnosis and nasal CT results about sinusitis (P < 0.01)., Conclusion: These results demonstrated that the differences of sinus development exist between the healthy children and children with sinusitis, and the sinus development in children with sinusitis were better than that of healthy children.

Objective: In order to make a basis for the treatment of nasal sinuses of children and the correlated disease, we investigate the incidence rate of nasal sinusitis of children and explore the correlation between nasal sinusitis of children and CT in Kunming., Method: Two thousand one hundred and fourteen healthy children and 1535 children with sinusitis were selected randomly. Form whom were undergone nasal sinus computer tomography for different medical reasons. The incidence rates of nasal sinusitis in different age-groups were calculated and statistically analyzed., Result: The incidence rate of sinusitis was highest in 4 to 8 years old. There was moderate to high consistency between clinical diagnosis and nasal CT results (P<0.01)., Conclusion: These results demonstrate that the key stage of children's sinusitis prevention would be school-age children, and nasal CT scanning is helpful to evaluate the clinical condition.

Objective: To analyze the characteristics of respiration events of sleep disordered breathing in children., Method: Thirty-two guide polysomnography was monitored in 203 snoring children. According to AHI and AI, they were divided into five groups and the results were analyzed by polysmith., Result: The mean value of REM was higher than that of NREM. The mean value between apnea and hypopnea have significant differences (P<0.01)., Conclusion: 1) Respiration events of children mostly happen in REM. 2) The mean value of hypopnea is higher than that of apnea. 3) Diagnosing obstructive sleep apnea hypopnea syndrome in children as AI > or = 1 need research.

Objective: To investigate the relationship between blood levels of lead and the function states of cochlear outer hair cells (OHC)., Method: Two hundred and fifty-six children lived in Pb-Zn mine area and Yiliang country, aged from 6 to 7 years were enrolled in this study. Blood lead (B-Pb) levels were measured. Otoacoustic emission (OAE) tests including transient evoked otoacoustic emissions (TEOAE) and distortion products otoacoustic emission (DPOAE) were also measured in these children., Result: The difference in B-Pb levels between the school children who lived in mine area and children lived in country was significant (P < 0.01). There were negative correlations between the B-Pb levels and the signal to noise ratio (SNR) on DPOAE test in children who lived in country and those lived in mine area (P < 0.01). The difference in relative coefficients of B-Pb levels between the children lived in mine and children lived in country were significant (P < 0.01)., Conclusion: The B-Pb levels of children who lived in mine area were higher than that of those lived in country. SNR decreased in plumbism cases. Long-term Pb expose may influence the function of cochlear OHC and higher B-Pb levels may lead to worse function of OHC.