普通炮采工作面支护密度的合理确定

来源 :煤矿安全 | 被引量 : 0次 | 上传用户:sam4567
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
本文根据现场生产和实测资料,从理论上论述了回采工作面支护密度的确定方法。回采工作面支护密度主要考虑每棵支柱的支护面积,其值依据顶板压力大小和支柱平均工作阻力而定。支护面积确定后,综合考虑工作面各项指标及参数,确定排、柱距。
其他文献
以BF3.OEt2为催化剂,在室温下通过4-羟基-N-苯基[1,3]苯并噁嗪-2-酮的脱羟基产生N-苯基[1,3]苯并噁嗪正离子,然后与富电子烯烃发生Diels-Alder反应,合成出了一系列喹啉并[1,2-c1,3]
A highly practical and efficient preparation of 6-methy-4H-thiochromene and 7-methyl-thiochromene[2,3-d]pyrimidine derivatives was developed via a multi-compone
Luteinizing hormone-releasing hormone (LHRH) is the key regulator of the hypothalamic-pituitary-gonadal (HPG) axis, which is responsible for the development and
A series of substituted 2-(2-hydroxyphenylimino) phenolic (salen) derivatives (1-4) have been synthesized and their structures of obtained compound were charact
Unprecedented cycloaddition reactions of azatrienes (1) with sulfene leading to the synthesis of functionalized thiazinedioxide derivatives (5) are described. T
根据第六次全国人口普查的初步结果,中国人口总量仍然较大,但增速明显放缓;中国正经历着深刻的人口转变,今后面临的人口问题将由人口的数量控制为主转变为人口存量、素质、结构和
Introduction: Pyridone derivatives played important roles in the last decade to approach many and different functionalities, especially as antitumor, antibacter
2015年5月29日,西北地区高校教师教学发展中心联盟成立大会在西安交通大学隆重举行,联盟共吸引了来自西北五省的130所高校和单位加盟。教育部高教司副司长韩筠,陕西省教育厅常务