Let R be an s-unital ring, and we prove a commutativity theorem of R satisfying the following conditions: (l ) For each x, y∈ R,there exist bounded positive integers k =k (x,y), s=s (x,y), t =t (x,y)(where, at least...Let R be an s-unital ring, and we prove a commutativity theorem of R satisfying the following conditions: (l ) For each x, y∈ R,there exist bounded positive integers k =k (x,y), s=s (x,y), t =t (x,y)(where, at least one of k, s, t is not equal to 1) such展开更多
In this note we show that the Mason’s upper bound of deg(u) for S-units u andv satisfying u + v = 1 over function field K = k(C) can be attained for any algebraicallyclosed coefficient field k and for some hyperellip...In this note we show that the Mason’s upper bound of deg(u) for S-units u andv satisfying u + v = 1 over function field K = k(C) can be attained for any algebraicallyclosed coefficient field k and for some hyperelliptic or Artin-Schreier curve C over k withany given genus g≥0.展开更多
S Zorb装置程控阀的可靠性运行是成品汽油硫含量达标的关键。程控阀的阀体、附件等在阀门的频繁动作以及恶劣现场环境下会产生一系列问题,影响装置的稳定性。使用故障模式影响与危害度分析(FMECA)方法分析程控阀各子系统故障严重性,利...S Zorb装置程控阀的可靠性运行是成品汽油硫含量达标的关键。程控阀的阀体、附件等在阀门的频繁动作以及恶劣现场环境下会产生一系列问题,影响装置的稳定性。使用故障模式影响与危害度分析(FMECA)方法分析程控阀各子系统故障严重性,利用模糊评价与层次分析法(AHP)建立程控阀维护策略,将二者组合形成FMECA-AHP方法,并应用于某石化公司S Zorb装置。结果表明:采用FMECA-AHP方法对程控阀各子系统故障进行等级划分并设计维护策略,可有效提高S Zorb装置程控阀维护效率,该方法高效、可靠,降低了成本,为企业创造了效益。展开更多
中国石油化工股份有限公司洛阳分公司150 kt/a S Zorb装置首次开工运行后,因加工负荷及进料硫含量低,装置出现汽油脱硫率过高、产品硫含量过低、汽油辛烷值损失大的问题.经过不断探讨,摸索出吸附剂“大硫差、小循环量”的操作方法.采用...中国石油化工股份有限公司洛阳分公司150 kt/a S Zorb装置首次开工运行后,因加工负荷及进料硫含量低,装置出现汽油脱硫率过高、产品硫含量过低、汽油辛烷值损失大的问题.经过不断探讨,摸索出吸附剂“大硫差、小循环量”的操作方法.采用吸附剂低活性、高空速、降低氢油比、提高反应温度等操作条件,不仅可将汽油脱硫的辛烷值（RON）损失由0.9～1.3降至0.5个单位以下,同时也减少吸附剂细粉生成,降低剂耗,减小程控阀、膨胀节、过滤器等关键设备的磨损,延长设备运行周期,降本增效.展开更多
文摘Let R be an s-unital ring, and we prove a commutativity theorem of R satisfying the following conditions: (l ) For each x, y∈ R,there exist bounded positive integers k =k (x,y), s=s (x,y), t =t (x,y)(where, at least one of k, s, t is not equal to 1) such
文摘In this note we show that the Mason’s upper bound of deg(u) for S-units u andv satisfying u + v = 1 over function field K = k(C) can be attained for any algebraicallyclosed coefficient field k and for some hyperelliptic or Artin-Schreier curve C over k withany given genus g≥0.
文摘中国石油化工股份有限公司洛阳分公司150 kt/a S Zorb装置首次开工运行后,因加工负荷及进料硫含量低,装置出现汽油脱硫率过高、产品硫含量过低、汽油辛烷值损失大的问题.经过不断探讨,摸索出吸附剂“大硫差、小循环量”的操作方法.采用吸附剂低活性、高空速、降低氢油比、提高反应温度等操作条件,不仅可将汽油脱硫的辛烷值（RON）损失由0.9～1.3降至0.5个单位以下,同时也减少吸附剂细粉生成,降低剂耗,减小程控阀、膨胀节、过滤器等关键设备的磨损,延长设备运行周期,降本增效.
