The newly discovered Shanzhuang BIF is hosted in the Shancaoyu Formation of the Taishan Group within the Eastern Block,southeastern margin of the North China Craton.The ores can be subdivided into three types in terms...The newly discovered Shanzhuang BIF is hosted in the Shancaoyu Formation of the Taishan Group within the Eastern Block,southeastern margin of the North China Craton.The ores can be subdivided into three types in terms of mineral assemblages,corresponding to three types(Ⅰ,Ⅱ,Ⅲ).The element concentration of the type Ⅰ magnetite is similar to that of the type Ⅱ magnetite,while the type Ⅲ magnetite is similar to that of the schist.In general,magnetite and hemat ite grains from the ores show high concentrations of Mn(1317,1162 ppm),Co(787,1023 ppm),Al(2224,2435 ppm)and Ti(540,300 ppm),Whereas magnetite is depleted in Si(420 ppm)and hematite enriched in Si(1690 ppm).Detailed petrographic and mineral chemical analysis of magnetite,hematite,amphibole/hornblende and pyroxene,reveals that almost all the minerals occur as subhedral-anhedral grains with pits and fractures,and the BIF is recrystallized to metamorphic assemblages of high amphibolite facies.Hornblende is highly enriched in Fe,Mg and Ca,but depleted in K and Na,mostly belonging to magnesiohornblende.In addition,the ratios of Mg/(Mg+Fe^2+),Fe^3+/(Fe^3++Fe^2+),Si/(Si+Ti+Al)and Al/Si are 0.48-0.64,0.17-0.36,0.79-0.88 and 0.14-0.27,respectively.It is suggested that hornblende is neither a typical magmatic origin nor a typical metamorphic.Pyroxene has the characteristics of high Ca and Fe,but low Ti and Al,with end-member components En,Wo and Fs in the ranges of 25.22-28.64 wt%,43.71-46.40 wt%and 24.51-27.62 wt%,respectively,belonging to clinopyroxene,and mostly diopside,might be formed during the prograde metamorphism in the absence of H2 O.The carbonate such as dolomite-ankerite series is probably a precursor mineral of the BIF deposit.Mass mineral chemical and structural characteristics indicate that the Shanzhuang iron deposit has been subjected to varying degrees of oxidized hydrothermal superimposed reformation,metamorphism,and supergenesis after mineralization,during which some elements have been migrated in some degree.展开更多
提出一种在车体和车下设备之间进行主动减振控制的改进方法,该方法主要采用线性二次型最优控制策略和优化技术。首先用扫频法确定车体与车下设备的低阶耦合共振频率为8.2 Hz。然后分别在同步正弦和延迟随机激扰下求解最优控制参数。发...提出一种在车体和车下设备之间进行主动减振控制的改进方法,该方法主要采用线性二次型最优控制策略和优化技术。首先用扫频法确定车体与车下设备的低阶耦合共振频率为8.2 Hz。然后分别在同步正弦和延迟随机激扰下求解最优控制参数。发现以时域性能为目标时,时域响应幅值能显著降低,但只能在耦合共振频率附近降低振动能量。为克服这一不足,提出以频率性能为目标的控制参数优化方法,所得控制参数能使车体加速度的均方根(Root mean squared,RMS)值降低40%以上。并能在较宽的频段内降低振动能量,恰好弥补了以时域性能为目标的不足。最后分析了参数扰动对控制效果的影响。结果表明,在车体质量±5%的变化范围内,加速度RMS值的降幅在40%以上;轨道激扰增加不超过2%的随机高斯噪声时,加速度RMS值的降幅在10%以上。因此,改进后的方法,不仅能有效降低车体振动,而且具有一定的控制“裕量”,可以保证工况条件劣化后的减振效果。展开更多
基金financially supported by the National Natural Science Foundation of China(Grants No.41503038,41140025,41672084,41372086)Special fund for“Taishan scholars”project in Shandong Province,Key R&D Program of Shandong Province(Grant No.2019GSF109101)+2 种基金Key R&D Program of China(Grants No.2016YFC0600105-04,2016YFC0600606)Shandong Provincial Natural Science Foundation(Grant No.ZR2019PD005)Shandong Key Laboratory of Mineralization Geological Processes and Resources Utilization in Metallic Minerals(Grant No.kfkt201809)。
文摘The newly discovered Shanzhuang BIF is hosted in the Shancaoyu Formation of the Taishan Group within the Eastern Block,southeastern margin of the North China Craton.The ores can be subdivided into three types in terms of mineral assemblages,corresponding to three types(Ⅰ,Ⅱ,Ⅲ).The element concentration of the type Ⅰ magnetite is similar to that of the type Ⅱ magnetite,while the type Ⅲ magnetite is similar to that of the schist.In general,magnetite and hemat ite grains from the ores show high concentrations of Mn(1317,1162 ppm),Co(787,1023 ppm),Al(2224,2435 ppm)and Ti(540,300 ppm),Whereas magnetite is depleted in Si(420 ppm)and hematite enriched in Si(1690 ppm).Detailed petrographic and mineral chemical analysis of magnetite,hematite,amphibole/hornblende and pyroxene,reveals that almost all the minerals occur as subhedral-anhedral grains with pits and fractures,and the BIF is recrystallized to metamorphic assemblages of high amphibolite facies.Hornblende is highly enriched in Fe,Mg and Ca,but depleted in K and Na,mostly belonging to magnesiohornblende.In addition,the ratios of Mg/(Mg+Fe^2+),Fe^3+/(Fe^3++Fe^2+),Si/(Si+Ti+Al)and Al/Si are 0.48-0.64,0.17-0.36,0.79-0.88 and 0.14-0.27,respectively.It is suggested that hornblende is neither a typical magmatic origin nor a typical metamorphic.Pyroxene has the characteristics of high Ca and Fe,but low Ti and Al,with end-member components En,Wo and Fs in the ranges of 25.22-28.64 wt%,43.71-46.40 wt%and 24.51-27.62 wt%,respectively,belonging to clinopyroxene,and mostly diopside,might be formed during the prograde metamorphism in the absence of H2 O.The carbonate such as dolomite-ankerite series is probably a precursor mineral of the BIF deposit.Mass mineral chemical and structural characteristics indicate that the Shanzhuang iron deposit has been subjected to varying degrees of oxidized hydrothermal superimposed reformation,metamorphism,and supergenesis after mineralization,during which some elements have been migrated in some degree.
文摘提出一种在车体和车下设备之间进行主动减振控制的改进方法,该方法主要采用线性二次型最优控制策略和优化技术。首先用扫频法确定车体与车下设备的低阶耦合共振频率为8.2 Hz。然后分别在同步正弦和延迟随机激扰下求解最优控制参数。发现以时域性能为目标时,时域响应幅值能显著降低,但只能在耦合共振频率附近降低振动能量。为克服这一不足,提出以频率性能为目标的控制参数优化方法,所得控制参数能使车体加速度的均方根(Root mean squared,RMS)值降低40%以上。并能在较宽的频段内降低振动能量,恰好弥补了以时域性能为目标的不足。最后分析了参数扰动对控制效果的影响。结果表明,在车体质量±5%的变化范围内,加速度RMS值的降幅在40%以上;轨道激扰增加不超过2%的随机高斯噪声时,加速度RMS值的降幅在10%以上。因此,改进后的方法,不仅能有效降低车体振动,而且具有一定的控制“裕量”,可以保证工况条件劣化后的减振效果。
