Combined with sedimentary observation and mineralogical research on a type of drusy celestite of early diagenesis in origin, this geochemical study on the Qixia Formation at the Shuibuya Section, Badong County, Hubei ...Combined with sedimentary observation and mineralogical research on a type of drusy celestite of early diagenesis in origin, this geochemical study on the Qixia Formation at the Shuibuya Section, Badong County, Hubei Province of south China evaluates the contribution of sedimentation and diagenesis to the mass fractions of CaO, Al 2O 3, MgO, SiO 2, Fe 2O 3, Na 2O, K 2O, Mn, Sr, P and Ba in the carbonates. The Sr, initially released from the stabilization of carbonate calcium mineral, precipitated with sulfate ion as celestite in early diagenetic environment, where sulfate reduction was the minimum. Then it redistributed in burial diagenetic environment, where celestite was replaced by calcite. The fractions of the MgO and SiO 2 in the carbonates were mainly modified by the early dolomitization and silicification respectively. That of the Na 2O was overprinted by the burial diagenesis. Multivariate statistical analysis on data of sixty bulk rocks indicates that the mass fractions of the Al 2O 3, K 2O, Fe 2O 3, Mn, CaO, P and Ba were affiliated with the sedimentary factor despite the obvious decrease of CaO during early dolomitization and silicification. Among them, the Al 2O 3 and K 2O mainly represent the detrital components. In addition, a dysaerobic sedimentary background was confirmed by trace element measurement and information derived from the formation of the celestite. This genetic discrimination facilitates the interpretation of the transgressive regressive (T R) cycle and specialities featured this unusual carbonate unit.展开更多
及时准确发现、隔离、排除牵引网线路故障,是电气化铁路牵引供电系统正常运行的重要举措。以最常见的单线直供牵引网T-R短路故障为例,基于对故障机理的分析,在Matlab/S i m u l i n k平台下建立了测控模型;同时为实现故障供电区块的准...及时准确发现、隔离、排除牵引网线路故障,是电气化铁路牵引供电系统正常运行的重要举措。以最常见的单线直供牵引网T-R短路故障为例,基于对故障机理的分析,在Matlab/S i m u l i n k平台下建立了测控模型;同时为实现故障供电区块的准确判断,提出了故障潮流符号值的概念,并在实际案例中得以应用。应用效果表明:该测控系统能够最大限度减少瞬时故障引起的误判,在保障无故障区段正常供电的前提下,可在60 ms内完成故障隔离,满足了电气化铁路保护系统的时限要求,提升了铁路运行质量。展开更多
文摘Combined with sedimentary observation and mineralogical research on a type of drusy celestite of early diagenesis in origin, this geochemical study on the Qixia Formation at the Shuibuya Section, Badong County, Hubei Province of south China evaluates the contribution of sedimentation and diagenesis to the mass fractions of CaO, Al 2O 3, MgO, SiO 2, Fe 2O 3, Na 2O, K 2O, Mn, Sr, P and Ba in the carbonates. The Sr, initially released from the stabilization of carbonate calcium mineral, precipitated with sulfate ion as celestite in early diagenetic environment, where sulfate reduction was the minimum. Then it redistributed in burial diagenetic environment, where celestite was replaced by calcite. The fractions of the MgO and SiO 2 in the carbonates were mainly modified by the early dolomitization and silicification respectively. That of the Na 2O was overprinted by the burial diagenesis. Multivariate statistical analysis on data of sixty bulk rocks indicates that the mass fractions of the Al 2O 3, K 2O, Fe 2O 3, Mn, CaO, P and Ba were affiliated with the sedimentary factor despite the obvious decrease of CaO during early dolomitization and silicification. Among them, the Al 2O 3 and K 2O mainly represent the detrital components. In addition, a dysaerobic sedimentary background was confirmed by trace element measurement and information derived from the formation of the celestite. This genetic discrimination facilitates the interpretation of the transgressive regressive (T R) cycle and specialities featured this unusual carbonate unit.
文摘及时准确发现、隔离、排除牵引网线路故障,是电气化铁路牵引供电系统正常运行的重要举措。以最常见的单线直供牵引网T-R短路故障为例,基于对故障机理的分析,在Matlab/S i m u l i n k平台下建立了测控模型;同时为实现故障供电区块的准确判断,提出了故障潮流符号值的概念,并在实际案例中得以应用。应用效果表明:该测控系统能够最大限度减少瞬时故障引起的误判,在保障无故障区段正常供电的前提下,可在60 ms内完成故障隔离,满足了电气化铁路保护系统的时限要求,提升了铁路运行质量。
