Numerical Simulation of the Rock SHPB Test with a Special Shape Striker Based on the Discrete Element Method   总被引：4，自引：3，他引：1  

Xibing Li  Yang Zou  Zilong Zhou 《Rock Mechanics and Rock Engineering》2014,47(5):1693-1709

A split Hopkinson pressure bar (SHPB) system with a special shape striker has been suggested as the test method by the International Society for Rock Mechanics (ISRM) to determine the dynamic characteristics of rock materials. In order to further verify this testing technique and microscopically reveal the dynamic responses of specimens in SHPB tests, a numerical SHPB test system was established based on particle flow code (PFC). Numerical dynamic tests under different impact velocities were conducted. Investigation of the stresses at the ends of a specimen showed that the specimen could reach stress equilibrium after several wave reverberations, and this balance could be maintained well for a certain time period after the peak stress. In addition, analyses of the reflected waves showed that there was a clear relationship between the variation of the reflected wave and the stress equilibrium state in the specimen, and the turning point of the reflected wave corresponded well with the peak stress in the specimen. Furthermore, the reflected waves can be classified into three types according to their patterns. Under certain impact velocities, the specimen deforms at a constant strain rate during the whole loading process. Finally, the influence of the micro-strength ratio ( \({{\tau_{\text{c}} } \mathord{\left/ {\vphantom {{\tau_{\text{c}} } {\sigma_{\text{c}} }}} \right. \kern-0pt} {\sigma_{\text{c}} }}\) ) and distribution pattern on the dynamic increase factor (DIF) of the strength DIF were studied, and the lateral inertia confinement and heterogeneity were found to be two important factors causing the strain rate effect for rock materials.  相似文献   

Dam deformation analysis based on BPNN merging models     

Jingui Zou  Yangxuan Xiao  Chinh Van Doan 《地球空间信息科学学报》2018,21(2):149-157

Hydropower has made a significant contribution to the economic development of Vietnam, thus it is important to monitor the safety of hydropower dams for the good of the country and the people. In this paper, dam horizontal displacement is analyzed and then forecasted using three methods: the multi-regression model, the seasonal integrated auto-regressive moving average (SARIMA) model and the back-propagation neural network (BPNN) merging models. The monitoring data of the Hoa Binh Dam in Vietnam, including horizontal displacement, time, reservoir water level, and air temperature, are used for the experiments. The results indicate that all of these three methods can approximately describe the trend of dam deformation despite their different forecast accuracies. Hence, their short-term forecasts can provide valuable references for the dam safety.  相似文献   

Experimental study of the movement of backfilling gangues for goaf in steeply inclined coal seams     

Yanchun Yin  Jianchao Zou  Yubao Zhang  Yue Qiu  Kai Fang  Dongmei Huang 《Arabian Journal of Geosciences》2018,11(12):318

For the coal mining with flexible shield supports which is used widely in the exploitation of steeply inclined coal seams, a method with which to backfill enough gangues efficiently in goaf is the key to meet the control requirements for the roof. In order to research the movement of gangues in goaf and the factors influencing backfilling effects, an experimental device for the movement of gangues for backfilling the goaf in steeply inclined coal seams was designed. The movement trajectory of gangues was monitored and was divided into three stages. Gangue movement characteristic under different engineering condition was studied, which showed that the backfilling rate of gangues in the goaf of steeply inclined coal seams is positively correlated to the dip angle of the coal seam and the mining thickness, while being negatively correlated to the grain size of the gangues and the deformation of the roof.  相似文献   

Response of rice production to elevated [CO2] and its interaction with rising temperature or nitrogen supply: a meta-analysis   总被引：1，自引：0，他引：1  

Jinyang Wang  Cong Wang  Nannan Chen  Zhengqin Xiong  David Wolfe  Jianwen Zou 《Climatic change》2015,130(4):529-543

  相似文献   

HY-2卫星散射计热带气旋自动识别算法   总被引：2，自引：1，他引：1  

邹巨洪  林明森  邹斌  郭茂华  崔松雪 《海洋学报》2015,37(1):73-79

对基于HY-2卫星散射计风矢量产品的热带气旋自动识别算法进行了研究。算法分为粗搜索与精搜索两部分。粗搜索利用热带气旋风场的风速与风向分布直方图特征确定搜索的阈值,快速剔除比较容易识别的非热带气旋区域。在此基础上,精搜索利用热带气旋风向的螺旋状分布特征,通过搜索目标区域内是否存在螺旋状流线的方法,确定目标区域的风向是否存在螺旋状流线特征,从而实现对热带气旋的准确自动识别。作为示例,将该方法应用到对HY-2散射计观测到的2012年6号强热带风暴"杜苏芮"的自动识别,结果表明,本文提出的算法可以从HY-2散射计风场数据中准确有效的自动识别出热带气旋。  相似文献   

探空气球漂移特征及对三角形法计算散度的影响   总被引：1，自引：1，他引：0       下载免费PDF全文

王学忠  胡邦辉  王举  黄泓  邹勋 《应用气象学报》2015,26(3):319-327

利用2006—2013年南京站、安庆站和杭州站探空资料,讨论华东地区探空气球的漂移特征。设计不考虑气球漂移、考虑全部气球漂移和考虑部分气球漂移3个试验,比较3种情况下三角形法计算的散度差异。结果表明:气球漂移主要受大气环流及其变化影响,纬向上7月和8月气球随高度增加,先向东漂移、后向西漂移,其他月份以向东漂移为主,冬季漂移距离大;经向上受季风影响明显。考虑全部和部分气球漂移与不考虑气球漂移的散度对比表明,平均绝对偏差各月在对流层顶附近均有极大值;相对偏差季节分布明显,前者在6—9月较大,极大值略大于7%,后者冬季大,1月在200 hPa达到25%,在50 hPa超过50%。因此,利用三角形法计算散度所在层次较高或所使用资料中传统探空和特种探空并存时,均需考虑气球漂移影响。  相似文献   

“北京气象”手机客户端气象信息GIS快速可视化技术   总被引：3，自引：0，他引：3  

邹建明  李迅  丁德平  陈小满 《气象科技》2015,43(4):634-639

随着移动互联网和智能手机技术的发展,客户端APP应用是满足便捷、高效、可移动、可定位气象信息服务的重要途径和手段。通过对格点天气、雷达回波、专题图等更新频次高、空间分辨率高、数据量较大的气象信息手机客户端GIS快速可视化关键技术的研究和实践,提出在服务器端应用支撑层部署Surfer专业绘图软件,在客户端数据资源层部署Google预先渲染好的离线栅格瓦片地图,应用支撑层部署开源的OpenLayers WebGIS二次开发组件,在两端应用逻辑层采用数据缓存和分布式存贮技术的手机客户端气象信息GIS快速可视化J2EE技术架构,实现了格点产品、雷达回波、专题图等气象信息GIS快速可视化展示。  相似文献   

KIS地震仪表系统软件设计     

邹彤  郭唐永  周云耀  陈志高  林晖  王培源  李欣 《大地测量与地球动力学》2007,27(Z1):91-93

介绍KIS地震仪表系统的功能与软件的结构组成，对软件开发中存在的问题及下一步发展方向进行探讨。  相似文献   

西秦岭北缘断裂带和海原断裂带断层泥粒度分布和分形研究   总被引：1，自引：0，他引：1  

邵顺妹  邹谨敞 《内陆地震》2000,14(1):30-37

用筛选法和悬浮法相结合的方法对采自西秦岭北缘断裂带东段和海原断裂带西段的天然断层泥进行了粒度分布和分形研究。 研究结果表明 这2条断裂带断层泥粒度组成为粗粒级(Φ＜4)含量高，细粒级(Φ≥4)含量低； 断层泥分维值分别为2.594±0.122和2.654±0.112，分维上限分别为2 cm和1 cm。  相似文献   

实施西部大开发给贵州省测绘行业带来的机遇和挑战     

邹志鸣 《地理信息世界》2000,(2)

党中央制定西部大开发的发展战略给贵州测绘行业带来了机遇，西部的环境、资源、交通等各项建设都离不开地图和数据产品的作用。因此需要测绘行业加强技术装备建设，提高测绘产品质量，为西部大开发作贡献。  相似文献