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小学语文“过度作业”的表现形式及其破解
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作者 戴佳佳 梅培军 《教学研究》 2023年第3期76-81,共6页
学生作业负担过重是义务教育的一大痼疾,国家发布的“双减”意见明确指出,要减轻义务教育阶段学生过重的作业负担。结合双减意见文件以及当前小学语文作业布置现状,将小学语文“过度作业”归纳为超难度作业、高时长作业、机械性作业、... 学生作业负担过重是义务教育的一大痼疾,国家发布的“双减”意见明确指出,要减轻义务教育阶段学生过重的作业负担。结合双减意见文件以及当前小学语文作业布置现状,将小学语文“过度作业”归纳为超难度作业、高时长作业、机械性作业、同质化作业等4种表现形式,并分析4类作业的症结及其对学生产生的消极影响,以此建议探索精准高效型、生活实践型、创意激趣型、分层选择型、评价指导型等作业形式,破解过度作业现象。 展开更多
关键词 小学语文 过度作业 作业设计
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Effects of proper drilling control to reduce respirable dust during roof bolting operations 被引量:6
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作者 Mingming Li Yi Luo Hua Jiang 《International Journal of Coal Science & Technology》 EI 2016年第4期370-378,共9页
Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fin... Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fine rock partic- ulates from drilling could escape from the dust collection system and become airborne under some circumstances causing the roof bolter operators expose to quartz-rich respirable dust. A previous research shows that drilling can be controlled through properly selected penetration and rotational rates to reduce the specific energy of drilling. Less specific energy means less energy is wasted on generating noise, heat and over-breakage of rock. It implies that proper control of drilling has a great potential to generate significantly less fine rock dust during drilling. The drilling experiments have been conducted to study the effect of controlling drilling on reducing respirable dust. The preliminary results show that the size distributions of respirable dust were different when controlling drilling in different bite depths. This paper presents the findings from laboratory experimental studies. 展开更多
关键词 Drilling control Roof bolting Bite depth Respirable dust Size distribution
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