本文综述国内外学者对学习策略的理解,以Oxford(1990)语言学习测量表(Strategy Inventory for Language Learning)为测量工具,以民族地区某中学初三年级学生为研究对象,探讨了三个问题,即该校初三年级学生使用英语学习策略特征,分析SIL...本文综述国内外学者对学习策略的理解,以Oxford(1990)语言学习测量表(Strategy Inventory for Language Learning)为测量工具,以民族地区某中学初三年级学生为研究对象,探讨了三个问题,即该校初三年级学生使用英语学习策略特征,分析SILL信度差异及英语学习策略与初三年级英语毕业考试成绩之间的关系。笔者同时提出如何因地制宜地运用学习策略,提高少数民族地区中学英语教学质量的建设性意见。展开更多
Steeply dipping,vein and tabular orebodies are traditionally extracted with longitudinal retreat mining methods such as Eureka and Avoca in a bottom-up sequence with delayed backfill.To increase productivity,sill pill...Steeply dipping,vein and tabular orebodies are traditionally extracted with longitudinal retreat mining methods such as Eureka and Avoca in a bottom-up sequence with delayed backfill.To increase productivity,sill pillars in the orebody are used to separate mining zones thus allowing production to take place simultaneously in two or more zones.While such mining methods are productive,they may be accompanied with high volumes of hanging wall overbreak causing significant unplanned ore dilution.In this work,it is shown through a mine design case study of a narrow vein deposit that a sill pillar could also play a significant role in limiting hanging wall overbreak.To demonstrate the role of sill pillar,a novel numerical modelling scheme is proposed to account for progressive stope wall overbreak.A numerical modelling approach of element death and rebirth is developed to allow for the detected stope overbreak to be immediately removed and replaced with backfill material before upper-level stope extraction.It is further shown that the average overbreak volume could be reduced by as much as 33%when the sill pillar is strategically placed in the lower half of a mine plan.展开更多
文摘本文综述国内外学者对学习策略的理解,以Oxford(1990)语言学习测量表(Strategy Inventory for Language Learning)为测量工具,以民族地区某中学初三年级学生为研究对象,探讨了三个问题,即该校初三年级学生使用英语学习策略特征,分析SILL信度差异及英语学习策略与初三年级英语毕业考试成绩之间的关系。笔者同时提出如何因地制宜地运用学习策略,提高少数民族地区中学英语教学质量的建设性意见。
基金financially supported by the Natural Science and Engineering Research Council(NSERC)-Discovery Grants Program。
文摘Steeply dipping,vein and tabular orebodies are traditionally extracted with longitudinal retreat mining methods such as Eureka and Avoca in a bottom-up sequence with delayed backfill.To increase productivity,sill pillars in the orebody are used to separate mining zones thus allowing production to take place simultaneously in two or more zones.While such mining methods are productive,they may be accompanied with high volumes of hanging wall overbreak causing significant unplanned ore dilution.In this work,it is shown through a mine design case study of a narrow vein deposit that a sill pillar could also play a significant role in limiting hanging wall overbreak.To demonstrate the role of sill pillar,a novel numerical modelling scheme is proposed to account for progressive stope wall overbreak.A numerical modelling approach of element death and rebirth is developed to allow for the detected stope overbreak to be immediately removed and replaced with backfill material before upper-level stope extraction.It is further shown that the average overbreak volume could be reduced by as much as 33%when the sill pillar is strategically placed in the lower half of a mine plan.
