The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding r...The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding rock was excavated. Our simula-tion results show that there are two kinds of dominating factors affecting roadway stability at points of intersection, one is the angle between horizontal stress and axial direction of the roadway and the other are the angles at the points of intersection. These results are based on a study we carried out as follows: first, we analyzed the failure mechanism of a large span intersection and then we built a mechanical model of a rock pillar at one of the points of intersection. At the end of this analysis, we obtained the failure characteristics of the critical parts on the large span intersection. Given these failure characteristics, we proposed a new supporting method, i.e., a Double-Bolt Control Technology (DBCT). By way of numerical simulation, DBCT can effectively control the deformation of the surrounding rock at the points of intersection in roadways.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Financial supports for this work, provided by the Major Program of the National Natural Science Foundation of China (No.50490270)the National Basic Research Program of China (973) (No. 2006CB202200) the Innovation Term Project of Ministry of Education of China (No.IRT0656), are gratefully acknowledged
文摘The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding rock was excavated. Our simula-tion results show that there are two kinds of dominating factors affecting roadway stability at points of intersection, one is the angle between horizontal stress and axial direction of the roadway and the other are the angles at the points of intersection. These results are based on a study we carried out as follows: first, we analyzed the failure mechanism of a large span intersection and then we built a mechanical model of a rock pillar at one of the points of intersection. At the end of this analysis, we obtained the failure characteristics of the critical parts on the large span intersection. Given these failure characteristics, we proposed a new supporting method, i.e., a Double-Bolt Control Technology (DBCT). By way of numerical simulation, DBCT can effectively control the deformation of the surrounding rock at the points of intersection in roadways.
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.
