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奶牛人工授精受胎率提高的技术措施 被引量:1
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作者 阿尔森别克.鲁纳尔别克 《现代畜牧科技》 2018年第11期59-59,共1页
奶牛人工授精技术可很大程度上提高奶牛的配种受胎率,但是还有很多养殖场存在配种受胎率仍然很低的现象,主要原因包括公牛精液的品质、母牛的饲养管理和健康,及输精技术等,需要从多方面入手采取有效的措施提高奶牛人工授精受胎率。
关键词 奶牛 人工授精 受胎率 影响在素 公牛 精液 发情 输精
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TBM tunneling in mixed-face ground: Problems and solutions 被引量:8
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作者 Ma Hongsu Yin Lijun +1 位作者 Gong Qiuming Wang Ju 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第4期641-647,共7页
Mixed-face ground encountered in Tunnel Boring Machine(TBM) tunneling presents great challenges and may trigger potential hazards without warning. A detailed understanding of such unfavorable conditions is therefore c... Mixed-face ground encountered in Tunnel Boring Machine(TBM) tunneling presents great challenges and may trigger potential hazards without warning. A detailed understanding of such unfavorable conditions is therefore critical to a successful bored tunnel. In this paper, we firstly present a brief review of the definition, classification and the factors related to mixed-face conditions. Secondly, for a better understanding of this topic, we investigate the main difficulties and problems involved in TBM tunnelling under mixed-face ground with detailed cases. Thirdly, from the viewpoint of rock-machine interaction, we give some suggestions on the corresponding mitigation measurements from three categories:(i) selection of TBM type and modification of TBM,(ii) condition of ground and(iii) optimization of TBM operation. 展开更多
关键词 TBM Mixed face ground Influencing factor Problems SOLUTIONS
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