Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area ...Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion, periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like (Mg, Al)-oxide is transformed into a composite with periclase (MgO) and spinel phases. The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.展开更多
由软锰矿的酸的猩鸿的 GR 的去色在这篇论文被学习。软锰矿，反应温度，和颤动速度去色效率的氢指数答案，剂量和颗粒度的 Theeffects 被讨论。根据实验结果，去色效率可以由软锰矿为 40 mg/L GR 答案超过 95% 。氢指数在影响酸的猩鸿的...由软锰矿的酸的猩鸿的 GR 的去色在这篇论文被学习。软锰矿，反应温度，和颤动速度去色效率的氢指数答案，剂量和颗粒度的 Theeffects 被讨论。根据实验结果，去色效率可以由软锰矿为 40 mg/L GR 答案超过 95% 。氢指数在影响酸的猩鸿的 GR 的去色的所有因素之中是很重要的。软锰矿，反应温度，和颤动速度的剂量和颗粒度在去色上有小 benitfit。Thehigh 去色效率和在软锰矿和酸的猩鸿的 GR 之间的产品的货到付款以及英尺红外系列的低移动效率显示酸的猩鸿的 GR 在矿物质的接口上经历氧化还原反应，它的色基是 oxidated 和 decolored，但是它没被氧化彻底地移开。展开更多
Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with L...Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with Late Mesozoic igneous or Carboniferous sedimentation.CPy from the Xinqiao deposit,a representative of the stratabound sulfide deposits in the MLYRMB,was studied by powder X-ray diffraction(XRD),field-emission scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(TEM).The results show that CPy mainly comprises pyrite,pyrrhotite,quartz,and illite.Pyrite in CPy shows cubic,globule,and xenomorphic morphologies.No octahedral or pyritohedron was observed.Most of the quartz crystals display xenomorphic morphology,where pyrite mold are popular on the surface.Organic matter(OM),which is usually bound to illite,is an important component in CPy.Morphological investigations which exhibit detrital features of quartz and clay minerals indicate that they were derived from continental weathering.Specially,some hexagonal pyrrhotite nanoparticles which show mackinawite morphology are coexisted with OM.The results indicate that the transformation process of sulfides possibly is mackinawite(the precursor)—hexagonal pyrrhotite-pyrite.Thus,compositional and micro-textural characteristics of CPy in Xinqiao deposit suggest it to be a sedimentary origin rather than a hydrothermal origin which is associated with Yanshanian magmatism.Moreover,the coexistence of CPy and stratabound sulfide orebodies in the MLYRMB suggests a causal link between the two.It is considered that CPy might have served as a Cu mineralization geochemical barrier for the Cu-bearing ore-forming fluids,which originated from the Mesozoic magma in the MLYRMB.展开更多
Magnetic susceptibility (MS) is one of the most important indicators of the East- Asia summer monsoon. Presented in this study is a high resolution magnetic susceptibility record from the Xifeng section, which consist...Magnetic susceptibility (MS) is one of the most important indicators of the East- Asia summer monsoon. Presented in this study is a high resolution magnetic susceptibility record from the Xifeng section, which consists of Quaternary loess-paleosol sequence and Pliocene red clay. Variations in magnetic susceptibility are well correlated with the δ18O record in deep-sea sediments and the eolian flux of Greenland. The climatic evolution in the Xifeng section shows that since the Late Tertiary, the driving force of the East-Asia paleo-monsoon is correlated with solar radiation on a 10-ka time scale .展开更多
1 Introduction Recently the demand for fossil fuel has grown significantly with the rapid development of the Chinese economy.Renewable energy was developed to replace traditional fossil fuels,which would decrease
基金the National Natural Science Foundation of China （No. 40472026） the 0utstanding 0verseas Chinese Scholars Fund of Chinese Academy of Sciences （2003-1-7）.
文摘Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion, periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like (Mg, Al)-oxide is transformed into a composite with periclase (MgO) and spinel phases. The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.
基金the National Natural Science Foundation of China （40472026）.
文摘由软锰矿的酸的猩鸿的 GR 的去色在这篇论文被学习。软锰矿，反应温度，和颤动速度去色效率的氢指数答案，剂量和颗粒度的 Theeffects 被讨论。根据实验结果，去色效率可以由软锰矿为 40 mg/L GR 答案超过 95% 。氢指数在影响酸的猩鸿的 GR 的去色的所有因素之中是很重要的。软锰矿，反应温度，和颤动速度的剂量和颗粒度在去色上有小 benitfit。Thehigh 去色效率和在软锰矿和酸的猩鸿的 GR 之间的产品的货到付款以及英尺红外系列的低移动效率显示酸的猩鸿的 GR 在矿物质的接口上经历氧化还原反应，它的色基是 oxidated 和 decolored，但是它没被氧化彻底地移开。
基金supported by the National Natural Science Foundation of China(Grant nos 41672038,41572029,41872043)the National Key Research and Development Program of China(Grant no.2016YFC0600209)。
文摘Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with Late Mesozoic igneous or Carboniferous sedimentation.CPy from the Xinqiao deposit,a representative of the stratabound sulfide deposits in the MLYRMB,was studied by powder X-ray diffraction(XRD),field-emission scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(TEM).The results show that CPy mainly comprises pyrite,pyrrhotite,quartz,and illite.Pyrite in CPy shows cubic,globule,and xenomorphic morphologies.No octahedral or pyritohedron was observed.Most of the quartz crystals display xenomorphic morphology,where pyrite mold are popular on the surface.Organic matter(OM),which is usually bound to illite,is an important component in CPy.Morphological investigations which exhibit detrital features of quartz and clay minerals indicate that they were derived from continental weathering.Specially,some hexagonal pyrrhotite nanoparticles which show mackinawite morphology are coexisted with OM.The results indicate that the transformation process of sulfides possibly is mackinawite(the precursor)—hexagonal pyrrhotite-pyrite.Thus,compositional and micro-textural characteristics of CPy in Xinqiao deposit suggest it to be a sedimentary origin rather than a hydrothermal origin which is associated with Yanshanian magmatism.Moreover,the coexistence of CPy and stratabound sulfide orebodies in the MLYRMB suggests a causal link between the two.It is considered that CPy might have served as a Cu mineralization geochemical barrier for the Cu-bearing ore-forming fluids,which originated from the Mesozoic magma in the MLYRMB.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40331001 and 40472026)
文摘Magnetic susceptibility (MS) is one of the most important indicators of the East- Asia summer monsoon. Presented in this study is a high resolution magnetic susceptibility record from the Xifeng section, which consists of Quaternary loess-paleosol sequence and Pliocene red clay. Variations in magnetic susceptibility are well correlated with the δ18O record in deep-sea sediments and the eolian flux of Greenland. The climatic evolution in the Xifeng section shows that since the Late Tertiary, the driving force of the East-Asia paleo-monsoon is correlated with solar radiation on a 10-ka time scale .
基金National Natural Science Foundation of China (41572326) for the support of this study
文摘1 Introduction Recently the demand for fossil fuel has grown significantly with the rapid development of the Chinese economy.Renewable energy was developed to replace traditional fossil fuels,which would decrease
