Based on the engineering project on a small coal pillar of 12,521 working face roadway in Xieqiao Coalmine, data regarding surface displacements of the coal pillar, deep displacements and mining stress have been colle...Based on the engineering project on a small coal pillar of 12,521 working face roadway in Xieqiao Coalmine, data regarding surface displacements of the coal pillar, deep displacements and mining stress have been collected and analyzed. The results show that macroscopic transverse fractures of the inner coal pillar are developed within 2–4 m of the roadway surface, which is located outside the coal pillar anchorage zone. There is a displacement of 530 mm at the monitoring point in the 6 m deep zone of the pillar. Transfer of the fracture zone is found in a small coal pillar and the fractures within 3–4 m of the coal-rock zone from the roadway surface undergo propagation and closure of cracks which means this fracture zone is transferred from 3–4 m outside the roadway to only 2–3 m from the roadway surface. In the monitoring zone, vertical and horizontal stresses increase with a feature that shows that acceleration in the deep zone of the pillar is greater than that in the shallow zone. Furthermore, the acceleration of vertical stress is also greater than that of horizontal stress with a peak value in the 4 m zone.The research findings provide a reference for the regulation of a reasonable width of coal pillar in coalmines and optimal control design of surrounding rock.展开更多
Objective:The aim of the study was to observe the characters and differences of the inner and outer parts of prostate gland, the prostatic cancer lesions in inner and outer parts of prostate glands by transrectal cont...Objective:The aim of the study was to observe the characters and differences of the inner and outer parts of prostate gland, the prostatic cancer lesions in inner and outer parts of prostate glands by transrectal contrast enhanced ultrasonography (TRCEUS) in order to provide valuable information for diagnosing of prostatic cancers. Methods: The ultrasound contrast agent was SonoVue (from Bracco Company, Italian). Instrument adopted Esaote Company Technos DU8 (transrectal ultrasonography). We observed the starting and ending times of transrectal contrast enhancement in the normal prostate inner gland group (16 cases), normal prostate outer gland group (16 cases), and the prostatic cancer lesions in inner gland group (8 cases) as well as in outer gland group (11 cases), respectively. Results: There was no significant difference in the starting time of the normal prostate glands between the inner gland and outer gland groups (P>0.05), likewise no significant difference between the cancer lesions in the inner gland and outer gland groups (P>0.05), but starting times of the cancer lesions in both groups were earlier than those of the normal prostate inner and outer glands groups (P<0.01). The ending time of enhancement was no significant difference among all groups (P>0.05). Conclusion: The earlier starting time of contrast enhancement in prostatic cancer lesions by TRCEUS has important value of distinguishing the cancer lesions from normal prostate glands. It is helpful to diagnose the prostatic cancer lesions.展开更多
基金the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1084)the Open Fund of Hunan provincial Key Laboratory for Safe Mining Technology of Coal Mine (No. 201103)the National Natural Science Foundation of China (No. 51274193)
文摘Based on the engineering project on a small coal pillar of 12,521 working face roadway in Xieqiao Coalmine, data regarding surface displacements of the coal pillar, deep displacements and mining stress have been collected and analyzed. The results show that macroscopic transverse fractures of the inner coal pillar are developed within 2–4 m of the roadway surface, which is located outside the coal pillar anchorage zone. There is a displacement of 530 mm at the monitoring point in the 6 m deep zone of the pillar. Transfer of the fracture zone is found in a small coal pillar and the fractures within 3–4 m of the coal-rock zone from the roadway surface undergo propagation and closure of cracks which means this fracture zone is transferred from 3–4 m outside the roadway to only 2–3 m from the roadway surface. In the monitoring zone, vertical and horizontal stresses increase with a feature that shows that acceleration in the deep zone of the pillar is greater than that in the shallow zone. Furthermore, the acceleration of vertical stress is also greater than that of horizontal stress with a peak value in the 4 m zone.The research findings provide a reference for the regulation of a reasonable width of coal pillar in coalmines and optimal control design of surrounding rock.
文摘Objective:The aim of the study was to observe the characters and differences of the inner and outer parts of prostate gland, the prostatic cancer lesions in inner and outer parts of prostate glands by transrectal contrast enhanced ultrasonography (TRCEUS) in order to provide valuable information for diagnosing of prostatic cancers. Methods: The ultrasound contrast agent was SonoVue (from Bracco Company, Italian). Instrument adopted Esaote Company Technos DU8 (transrectal ultrasonography). We observed the starting and ending times of transrectal contrast enhancement in the normal prostate inner gland group (16 cases), normal prostate outer gland group (16 cases), and the prostatic cancer lesions in inner gland group (8 cases) as well as in outer gland group (11 cases), respectively. Results: There was no significant difference in the starting time of the normal prostate glands between the inner gland and outer gland groups (P>0.05), likewise no significant difference between the cancer lesions in the inner gland and outer gland groups (P>0.05), but starting times of the cancer lesions in both groups were earlier than those of the normal prostate inner and outer glands groups (P<0.01). The ending time of enhancement was no significant difference among all groups (P>0.05). Conclusion: The earlier starting time of contrast enhancement in prostatic cancer lesions by TRCEUS has important value of distinguishing the cancer lesions from normal prostate glands. It is helpful to diagnose the prostatic cancer lesions.
