文章针对IP多媒体系统(IP multimedia subsystem,IMS)应用于电力行业与普通商用领域时,在用户容量、话务模型等方面存在的差异性,研究电力IMS网络功能虚拟化(network function virtualization,NFV)的单节点硬件部署方案。第一阶段,在商...文章针对IP多媒体系统(IP multimedia subsystem,IMS)应用于电力行业与普通商用领域时,在用户容量、话务模型等方面存在的差异性,研究电力IMS网络功能虚拟化(network function virtualization,NFV)的单节点硬件部署方案。第一阶段,在商用IMS的标准配置基础上,逐步缩减硬件资源,直至业务受损;第二阶段,根据电力系统的业务安全性要求,增加适当冗余度。规模化试点测试表明在20万用户、5000并发量下,电力IMS虚拟化硬件资源可压缩至商用配置的70.59%。研究结果可支撑国家电网IMS虚拟化演进工程设计。展开更多
In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rock...In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.展开更多
Rockburst occurred frequently during deep mining in China. The mechanism of rockburst is very complicated and related to many factors. In order to investigate the influence of moisture contents of rockmass on rockburs...Rockburst occurred frequently during deep mining in China. The mechanism of rockburst is very complicated and related to many factors. In order to investigate the influence of moisture contents of rockmass on rockburst, we conducted a series of laboratory rockburst experiments of sandstone under three different moisture contents by the Modified True-Triaxial Apparatus (MTTA),in which the acoustic emission (AE) system was employed to monitor the internal damage of rock mass. A high-speed video camera was utilized to record the detail of rockburst. Based on the experimental results, the AE characteristics, such as AE count,AE energy, and AE frequency, were analyzed. The rockburst process, type, and indensity under different moisture contents were discussed. The research results show that with the increase of moisture contents, rock strength was soften, the elastic and the cumulative damage of the rock were reduced, resulting in a gradual decrease in AE cumulative counts and cumulative energy over the course of rockburst. This study provides an experimental basis and reference for better understanding to the rockburst mechanism and control.展开更多
Large-scale physical model test of 30°inclined strata was conducted to investigate the damage mechanisms during the excavation and overloading using infrared detection.The experiment results were presented with t...Large-scale physical model test of 30°inclined strata was conducted to investigate the damage mechanisms during the excavation and overloading using infrared detection.The experiment results were presented with thermal images which were divided into three stages including a full face excavation stage,a staged excavation stage,and an overloading stage.The obtained results were compared with the previously reported results from horizontal,45?,60?,and vertical strata models.Infrared temperature(IRT)for 30°inclined strata model descended with multiple fluctuations during the full-face excavation.For the staged excavation,the excavation damage zone(EDZ)showed enhanced faulting-like strips as compared in the 45?,60?,and vertical models,indicating the intensified stress redistribution occurred in the adjacent rock mass.In contrast,EDZ for the horizontal strata existed in a plastic-formed manner.During the overloading,abnormal features in the thermal images were observed preceding the coalescence of the propagating cracks.The ultimate failure of the model was due primarily to the floor heave and the roof fall.展开更多
文摘目的了解山东大学体检人群前列腺癌(prostate cancer,PCa)的发病情况,分析相关影响因素,为本地PCa防治工作提供数据支撑。方法选取2022年3月—2023年12月在山东大学历下区社区卫生服务站进行体检并参与了基于血清前列腺特异性抗原(prostate specific antigen,PSA)检测的PCa筛查人群作为研究对象,共纳入3933例研究对象。PSA检测结果≥4μg/L者建议到医院就诊并进行前列腺穿刺活检。收集研究对象的基线资料,分析PSA异常和PCa发病的危险因素。结果在3933例体检对象中,PSA异常者477例(12.13%),其中54例PSA异常者接受了前列腺穿刺活检,穿刺意愿率为11.32%。经穿刺活检确诊为PCa者26例,总体PCa检出率为0.66%。高龄(OR=2.563;95%CI:2.034~3.229,P<0.001)、有前列腺炎病史(OR=2.217,95%CI:1.803~2.725,P<0.001)是PSA异常的危险因素。高龄(OR=3.486,95%CI:1.250~9.722,P=0.017)、正在大量吸烟(OR=3.680,95%CI:1.189~11.394,P=0.024)是PCa的危险因素。结论山东大学体检人群PCa检出率较高;PSA水平异常与年龄、前列腺炎病史有关。高龄、正在大量吸烟可能会增加PCa的发病风险。
文摘文章针对IP多媒体系统(IP multimedia subsystem,IMS)应用于电力行业与普通商用领域时,在用户容量、话务模型等方面存在的差异性,研究电力IMS网络功能虚拟化(network function virtualization,NFV)的单节点硬件部署方案。第一阶段,在商用IMS的标准配置基础上,逐步缩减硬件资源,直至业务受损;第二阶段,根据电力系统的业务安全性要求,增加适当冗余度。规模化试点测试表明在20万用户、5000并发量下,电力IMS虚拟化硬件资源可压缩至商用配置的70.59%。研究结果可支撑国家电网IMS虚拟化演进工程设计。
基金supported by program for the National Natural Science Foundation of China (No.51304210)the Specialized Research Foundation for the Doctoral Program of Higher Education by the Ministry of Education (No.20120023120014)
文摘In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51374214 , 51134005 & 51574248)the Special Fund of Basic Research and Operating of China University of Mining & Technology, Beijing (Grant No. 2009QL03)the State Scholarship Fund of China
文摘Rockburst occurred frequently during deep mining in China. The mechanism of rockburst is very complicated and related to many factors. In order to investigate the influence of moisture contents of rockmass on rockburst, we conducted a series of laboratory rockburst experiments of sandstone under three different moisture contents by the Modified True-Triaxial Apparatus (MTTA),in which the acoustic emission (AE) system was employed to monitor the internal damage of rock mass. A high-speed video camera was utilized to record the detail of rockburst. Based on the experimental results, the AE characteristics, such as AE count,AE energy, and AE frequency, were analyzed. The rockburst process, type, and indensity under different moisture contents were discussed. The research results show that with the increase of moisture contents, rock strength was soften, the elastic and the cumulative damage of the rock were reduced, resulting in a gradual decrease in AE cumulative counts and cumulative energy over the course of rockburst. This study provides an experimental basis and reference for better understanding to the rockburst mechanism and control.
基金supported by the National Key Research and Development Plan of China (Grant No. 2016YFC0600901)the National Natural Science Foundation of China (Grant Nos. 51374214, 51134005 & 51574248)+1 种基金the Special Fund of Basic Research and Operating of China University of Mining & Technology, Beijing (Grant No. 2009QL03)the State Scholarship Fund of China
文摘Large-scale physical model test of 30°inclined strata was conducted to investigate the damage mechanisms during the excavation and overloading using infrared detection.The experiment results were presented with thermal images which were divided into three stages including a full face excavation stage,a staged excavation stage,and an overloading stage.The obtained results were compared with the previously reported results from horizontal,45?,60?,and vertical strata models.Infrared temperature(IRT)for 30°inclined strata model descended with multiple fluctuations during the full-face excavation.For the staged excavation,the excavation damage zone(EDZ)showed enhanced faulting-like strips as compared in the 45?,60?,and vertical models,indicating the intensified stress redistribution occurred in the adjacent rock mass.In contrast,EDZ for the horizontal strata existed in a plastic-formed manner.During the overloading,abnormal features in the thermal images were observed preceding the coalescence of the propagating cracks.The ultimate failure of the model was due primarily to the floor heave and the roof fall.
