Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground su...Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground support requires good and reliable ground characterization. While many geophysical methods have been developed for ground characterizations, their accuracy is insufficient for customized ground support design of underground workings. The actual measurements on the samples of the roof and wall strata from the exploration boring are reliable but the related holes are far apart, thus unsuitable for design purposes. The best source of information could be the geological back mapping of the roof and walls, but this is disruptive to mining operations, and provided information is only from rock surface.Interpretation of the data obtained from roof bolt drilling can offer a good and reliable source of information that can be used for ground characterization and ground support design and evaluations. This paper offers a brief review of the mine roof characterization methods, followed by introduction and discussion of the roof characterization methods by instrumented roof bolters. A brief overview of the results of the preliminary study and initial testing on an instrumented drill and summary of the suggested improvements are also discussed.展开更多
A new IL-supported diol, 1-（2,3-dihydroxypropyl）-3-methylimidazolium hexafluorophosphate has been synthesized and characterized by Fr-IR, ^1H NMR, ^13C NMR and MS （ESI）. Its physical properties such as freezing po...A new IL-supported diol, 1-（2,3-dihydroxypropyl）-3-methylimidazolium hexafluorophosphate has been synthesized and characterized by Fr-IR, ^1H NMR, ^13C NMR and MS （ESI）. Its physical properties such as freezing point, solubility and specific gravity and thermal stability were determined. Synthetic utilities of the resultant diol as a protecting group for aldehydes were also investigated.展开更多
随着网页内容和功能的丰富以及用户体验需求的提升,移动Web浏览中的计算能耗与日俱增.DVFS(Dynamic Voltage and Frequency Scaling)技术在同构多核架构中取得较好的节能效果,但在异构多核架构中,由于系统默认的调度策略没有充分利用低...随着网页内容和功能的丰富以及用户体验需求的提升,移动Web浏览中的计算能耗与日俱增.DVFS(Dynamic Voltage and Frequency Scaling)技术在同构多核架构中取得较好的节能效果,但在异构多核架构中,由于系统默认的调度策略没有充分利用低功耗核心,导致高性能核心的工作频率和时间往往高于实际需求,浪费大量电能.而面向异构平台的Linux HMP(Heterogeneous Multi-Processing)技术也没有充分利用异构平台的特性,无法对能效进行有效的提升.针对上述问题,该文面向移动异构平台,提出了一种基于支持向量机的CPU配置预测模型.首先选取500个热门网站主页,分析其主页面的架构(HTML)及样式(CSS)信息,进行特征选择;遍历不同CPU配置渲染网页,记录获得最优加载时间、能耗及EDP对应CPU配置;最后在线下利用支持向量机自主挖掘网页特征同最优配置的内在关系,以此构建移动异构平台的CPU资源调度预测模型.该模型通过分析网页特征,根据不同的优化目标,为渲染引擎分配合适的处理器资源.实验结果显示,同目前最先进的一种线性回归预测模型相比,该文提出的CPU资源调度模型在加载时间、能耗和EDP上的性能得到显著提升.展开更多
定量的工业级Al2O3为原料,经过预烧、酸洗除杂质处理,以甲基纤维素为粘结剂,以活性碳粉为造孔剂,经过混料、捏泥、陈腐、真空练泥、挤出成型、干燥并且分别采用不同的温度烧结制备出无机陶瓷膜支撑体。通过对酸洗前后煤矸石原料进行XRF...定量的工业级Al2O3为原料,经过预烧、酸洗除杂质处理,以甲基纤维素为粘结剂,以活性碳粉为造孔剂,经过混料、捏泥、陈腐、真空练泥、挤出成型、干燥并且分别采用不同的温度烧结制备出无机陶瓷膜支撑体。通过对酸洗前后煤矸石原料进行XRF分析及对酸洗过程中不同盐酸浓度下及烧结过程中不同烧结温度下的支撑体进行了SEM、XRD、孔隙率以及抗压强度表征分析,发现100 g煤矸石预烧后用84 m L 38%的盐酸酸洗处理后的原料,在1050℃的高温下烧结保温2 h的支撑体各种性能较好,试样抗压强度达到9.34 MPa,孔隙率达到42%,符合陶瓷膜支撑体的预期要求。展开更多
基金supported by the funding of the National Institute for Occupational Safety and Health under a contract with the Pennsylvania State University as part of the capacity building in ground supportthe funding from TüBITAK of Turkey has been used to support the sabbatical leave of Dr.Kahraman who made some contributions to this study
文摘Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground support requires good and reliable ground characterization. While many geophysical methods have been developed for ground characterizations, their accuracy is insufficient for customized ground support design of underground workings. The actual measurements on the samples of the roof and wall strata from the exploration boring are reliable but the related holes are far apart, thus unsuitable for design purposes. The best source of information could be the geological back mapping of the roof and walls, but this is disruptive to mining operations, and provided information is only from rock surface.Interpretation of the data obtained from roof bolt drilling can offer a good and reliable source of information that can be used for ground characterization and ground support design and evaluations. This paper offers a brief review of the mine roof characterization methods, followed by introduction and discussion of the roof characterization methods by instrumented roof bolters. A brief overview of the results of the preliminary study and initial testing on an instrumented drill and summary of the suggested improvements are also discussed.
基金the National Natural Science Foundation of China(No.20533010,20673039)the Science&Technology Commission of Shanghai Municipality(No.06JC14023)for financial support.
文摘A new IL-supported diol, 1-（2,3-dihydroxypropyl）-3-methylimidazolium hexafluorophosphate has been synthesized and characterized by Fr-IR, ^1H NMR, ^13C NMR and MS （ESI）. Its physical properties such as freezing point, solubility and specific gravity and thermal stability were determined. Synthetic utilities of the resultant diol as a protecting group for aldehydes were also investigated.
文摘随着网页内容和功能的丰富以及用户体验需求的提升,移动Web浏览中的计算能耗与日俱增.DVFS(Dynamic Voltage and Frequency Scaling)技术在同构多核架构中取得较好的节能效果,但在异构多核架构中,由于系统默认的调度策略没有充分利用低功耗核心,导致高性能核心的工作频率和时间往往高于实际需求,浪费大量电能.而面向异构平台的Linux HMP(Heterogeneous Multi-Processing)技术也没有充分利用异构平台的特性,无法对能效进行有效的提升.针对上述问题,该文面向移动异构平台,提出了一种基于支持向量机的CPU配置预测模型.首先选取500个热门网站主页,分析其主页面的架构(HTML)及样式(CSS)信息,进行特征选择;遍历不同CPU配置渲染网页,记录获得最优加载时间、能耗及EDP对应CPU配置;最后在线下利用支持向量机自主挖掘网页特征同最优配置的内在关系,以此构建移动异构平台的CPU资源调度预测模型.该模型通过分析网页特征,根据不同的优化目标,为渲染引擎分配合适的处理器资源.实验结果显示,同目前最先进的一种线性回归预测模型相比,该文提出的CPU资源调度模型在加载时间、能耗和EDP上的性能得到显著提升.
文摘定量的工业级Al2O3为原料,经过预烧、酸洗除杂质处理,以甲基纤维素为粘结剂,以活性碳粉为造孔剂,经过混料、捏泥、陈腐、真空练泥、挤出成型、干燥并且分别采用不同的温度烧结制备出无机陶瓷膜支撑体。通过对酸洗前后煤矸石原料进行XRF分析及对酸洗过程中不同盐酸浓度下及烧结过程中不同烧结温度下的支撑体进行了SEM、XRD、孔隙率以及抗压强度表征分析,发现100 g煤矸石预烧后用84 m L 38%的盐酸酸洗处理后的原料,在1050℃的高温下烧结保温2 h的支撑体各种性能较好,试样抗压强度达到9.34 MPa,孔隙率达到42%,符合陶瓷膜支撑体的预期要求。
