为保证矿井安全高效生产,针对平煤股份公司六矿戊8-32010工作面机巷平均埋深700 m、瓦斯原始含量5.12 m 3/t,原始瓦斯压力0.52 MPa的情况,开展卸压切顶留巷工作。通过对留巷全过程矿压监测,分析成巷矿压分布规律,将留巷分为动压剧烈影...为保证矿井安全高效生产,针对平煤股份公司六矿戊8-32010工作面机巷平均埋深700 m、瓦斯原始含量5.12 m 3/t,原始瓦斯压力0.52 MPa的情况,开展卸压切顶留巷工作。通过对留巷全过程矿压监测,分析成巷矿压分布规律,将留巷分为动压剧烈影响区、动压缓慢影响区和成巷稳定区三部分,矿压分别来源于超前支承压力和留巷内顶板短悬臂梁失稳。留巷进入稳定区后,随着巷道超前支护液压支架等支护设施的撤除,巷道会出现二次稳定过程,主要源于顶板对于巷道超前支护液压支架工作阻力的再平衡。切顶留巷技术提高了工作效率,很好地解决了矿井采掘接替紧张的问题。展开更多
Tetraploid fish are important for mass production of triploids in polyploid breeding.In this study,we reported a novel protocol for artificial induction of tetraploidy by a combination of cold shock and hydrostatic pr...Tetraploid fish are important for mass production of triploids in polyploid breeding.In this study,we reported a novel protocol for artificial induction of tetraploidy by a combination of cold shock and hydrostatic pressure administered to gynogenetically developed eggs in Japanese flounder Paralichthys olivaceus.The induction was carried out by activating the eggs with UV-irradiated sperm of red sea bream Pagrus major,administering a cold shock(0℃,5 to 45 min)3 min after fertilization to inhibit second polar body exclusion,incubating the eggs for 60 min at 17℃,and treating them with a 650 kg/cm2 hydrostatics pressure shock for 6 min.We named the embryos gyno-tetraploids that developed from eggs after such treatments.The hatching rate of the gyno-tetraploids ranged from 20.99%±3.66%to 36.01%±2.79%,and the tetraploid rate ranged from 80.00%to 100.00%.All-maternal inheritance was verified using 6 high-recombination-rate microsatellite markers.This method successfully induced gyno-tetraploidy.The successful induction of gyno-tetraploidy lays the foundation for triploidization of new varieties with improved economic traits of interest that can benefit commercial culture.展开更多
文摘为保证矿井安全高效生产,针对平煤股份公司六矿戊8-32010工作面机巷平均埋深700 m、瓦斯原始含量5.12 m 3/t,原始瓦斯压力0.52 MPa的情况,开展卸压切顶留巷工作。通过对留巷全过程矿压监测,分析成巷矿压分布规律,将留巷分为动压剧烈影响区、动压缓慢影响区和成巷稳定区三部分,矿压分别来源于超前支承压力和留巷内顶板短悬臂梁失稳。留巷进入稳定区后,随着巷道超前支护液压支架等支护设施的撤除,巷道会出现二次稳定过程,主要源于顶板对于巷道超前支护液压支架工作阻力的再平衡。切顶留巷技术提高了工作效率,很好地解决了矿井采掘接替紧张的问题。
基金Supported by the Central Public-Interest Scientific Institution Basal Research Fund,CAFS(No.2016HY-ZD0202)the China Agriculture Research System(No.CARS-47)the Applied National Science and Technology Support Program in China(No.2012BAD26B01)
文摘Tetraploid fish are important for mass production of triploids in polyploid breeding.In this study,we reported a novel protocol for artificial induction of tetraploidy by a combination of cold shock and hydrostatic pressure administered to gynogenetically developed eggs in Japanese flounder Paralichthys olivaceus.The induction was carried out by activating the eggs with UV-irradiated sperm of red sea bream Pagrus major,administering a cold shock(0℃,5 to 45 min)3 min after fertilization to inhibit second polar body exclusion,incubating the eggs for 60 min at 17℃,and treating them with a 650 kg/cm2 hydrostatics pressure shock for 6 min.We named the embryos gyno-tetraploids that developed from eggs after such treatments.The hatching rate of the gyno-tetraploids ranged from 20.99%±3.66%to 36.01%±2.79%,and the tetraploid rate ranged from 80.00%to 100.00%.All-maternal inheritance was verified using 6 high-recombination-rate microsatellite markers.This method successfully induced gyno-tetraploidy.The successful induction of gyno-tetraploidy lays the foundation for triploidization of new varieties with improved economic traits of interest that can benefit commercial culture.
