In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combina...In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combination of fractured blocks as a voussoir beam. Using the plastic hmit theory of plates, th limit load acting on rnain floor and the position of its largest deformation are gotten. The stability conditions for the key blocks of the voussoir beam are analysed by "S-R" stability theory. The results of the theoretical analysis are important for the study on the water inrush from seam floor.展开更多
We report an extremely rare case of gas-filled abdominal mass caused by an ovarian teratoma fistulating to the sigmoid colon The patient was an 85-year-old female,who presented with severe abdominal distension Urgent ...We report an extremely rare case of gas-filled abdominal mass caused by an ovarian teratoma fistulating to the sigmoid colon The patient was an 85-year-old female,who presented with severe abdominal distension Urgent computed tomography scan showed a huge abdominal mass with air fluid level and fecal matter inside Communication between the mass and the sigmoid colon was suspected She underwent emergency laparotomy The mass was resected with the involved segment of colon Pathology confirmed squamous cell carcinoma arising from mature cystic teratoma of the ovary.展开更多
文摘In this paper a new mechanica1 medel indicating the mechanical behaviour of main floor in longwall mining is proposed. In the medel the unfractured rnain floor is considered as an elasto plastic plate, and the combination of fractured blocks as a voussoir beam. Using the plastic hmit theory of plates, th limit load acting on rnain floor and the position of its largest deformation are gotten. The stability conditions for the key blocks of the voussoir beam are analysed by "S-R" stability theory. The results of the theoretical analysis are important for the study on the water inrush from seam floor.
文摘We report an extremely rare case of gas-filled abdominal mass caused by an ovarian teratoma fistulating to the sigmoid colon The patient was an 85-year-old female,who presented with severe abdominal distension Urgent computed tomography scan showed a huge abdominal mass with air fluid level and fecal matter inside Communication between the mass and the sigmoid colon was suspected She underwent emergency laparotomy The mass was resected with the involved segment of colon Pathology confirmed squamous cell carcinoma arising from mature cystic teratoma of the ovary.
