Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combinatio...Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combination of lithofacies analysis and bulk-rock geochemical data.The lithofacies in the studied area were classified as gravel,sand,and fine-grained clastic lithofacies,reflecting generally channel fill deposits,channel bar deposits,and over-bank deposits,respectively.The Chemical Index of Alteration(CIA),Plagioclase Index of Alteration(PIA),and Chemical Index of Weathering(CIW)values ranged 50.10–62.29,50.13–66.35,56.52–71.12,respectively,together with element ratios such as Rb/Sr,K/Na,Rb/K,Th/K,Rb/Ti,and Cs/Ti indicate that the source area was under a low to moderate chemical weathering condition probably in cold and semi-arid climates.Moreover,plot of SiO_(2)vs.(Al_(2)O_(3)+K_(2)O+Na_(2)O)suggests that the sediments were deposited in a semi-arid climate.Plots of Cr/Th vs.Th/Sc,TiO_(2)vs.Zr,La/Yb vs.rare earth element(REE),and La-Th-Sc ternary diagrams,along with the lithology,indicate that the sediments in Fenghe River were mainly originated from felsic igneous rocks.Major elements-based discrimination diagrams and Th-Sc-Zr/10 and La-Th-Sc ternary diagram of the samples indicates that the source rocks of Fenghe River developed in a composite active continental margin and continental island arc field.展开更多
Objective:Ban Fenghe recorded in the Quality Standard of Yao Medicine of Guangxi Zhuang Autonomous Region(Volume 1)is derived from the dried stems and leaves of Semiliquidambar cathayensis.It is usually confused with ...Objective:Ban Fenghe recorded in the Quality Standard of Yao Medicine of Guangxi Zhuang Autonomous Region(Volume 1)is derived from the dried stems and leaves of Semiliquidambar cathayensis.It is usually confused with medicinal herbs from Pterospermum heterophyllum and Dendropanax dentiger.However,they are very different in chemical composition,and should not be used as the same drug.To ensure their safety and efficacy,a method based on macroscopic and microscopic characteristics was developed to distinguish them.Methods:A total of 14 batches of Ban Fenghe samples from three species were collected from different producing areas in China.The macroscopic characteristics were examined by observing external traits.The tissue structures of transverse sections of stems and leaves,the leaf epidermis,and the powder were observed microscopically.Results:The branchlets and leaf surfaces of S.cathayensis and P.heterophyllum were hairy,especially the lower leaf surfaces of P.heterophyllum were densely covered with hairs,but those of D.dentiger were hairless.The pericyclic fibers of S.cathayensis stems were intermittently distributed in a circular shape and accompanied by stone cells,whereas those of P.heterophyllum and D.dentiger were bundled without stone cells.So stone cells and hairs were present in S.cathayensis powder,stone cells were not found in P.heterophyllum and D.dentiger powder,and hairs were not present in D.dentiger powder.The distribution sites,sizes and types of secretory tissues of these three species were also different in transverse sections of stems and leaves.Stomata on the lower epidermis of S.cathayensis leaves were paracytic,whereas those of P.heterophyllum and D.dentiger were anomocytic.Conclusion:Ban Fenghe drugs derived from S.cathayensis could readily be distinguished from those of P.heterophyllum and D.dentiger by macroscopic and microscopic features.展开更多
Chinese State Councilor and Minister of National Defense Wei Fenghe gave a speech at the 18th Shangri-La Dialogue in Singapore on June 2,stating China's stance on international security cooperation.
基金Supported by the National Natural Science Foundation of China (Nos.42130206,41302076)the MOST Special Fund awarded by the State Key Laboratory of Continental Dynamics,Northwest University (No.201210128)the Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral,Shandong University of Science and Technology (No.DMSM2017033)。
文摘Six outcrop sections in Fenghe River,Northwestern China,were sampled and analyzed.This study aims to determine provenance,tectonic setting,and source-area paleoweathering of the sediments of Fenghe River in combination of lithofacies analysis and bulk-rock geochemical data.The lithofacies in the studied area were classified as gravel,sand,and fine-grained clastic lithofacies,reflecting generally channel fill deposits,channel bar deposits,and over-bank deposits,respectively.The Chemical Index of Alteration(CIA),Plagioclase Index of Alteration(PIA),and Chemical Index of Weathering(CIW)values ranged 50.10–62.29,50.13–66.35,56.52–71.12,respectively,together with element ratios such as Rb/Sr,K/Na,Rb/K,Th/K,Rb/Ti,and Cs/Ti indicate that the source area was under a low to moderate chemical weathering condition probably in cold and semi-arid climates.Moreover,plot of SiO_(2)vs.(Al_(2)O_(3)+K_(2)O+Na_(2)O)suggests that the sediments were deposited in a semi-arid climate.Plots of Cr/Th vs.Th/Sc,TiO_(2)vs.Zr,La/Yb vs.rare earth element(REE),and La-Th-Sc ternary diagrams,along with the lithology,indicate that the sediments in Fenghe River were mainly originated from felsic igneous rocks.Major elements-based discrimination diagrams and Th-Sc-Zr/10 and La-Th-Sc ternary diagram of the samples indicates that the source rocks of Fenghe River developed in a composite active continental margin and continental island arc field.
基金funded by the Project Promoting Basic Capacity for Young and Middle-aged University Teachers in Guangxi(No.2018KY0136)the Guangxi First-class Discipline Project for Pharmaceutical Sciences(No.GXFCDP-PS-2018)the Key Project at the Central Government Level:the Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources(No.2060302)。
文摘Objective:Ban Fenghe recorded in the Quality Standard of Yao Medicine of Guangxi Zhuang Autonomous Region(Volume 1)is derived from the dried stems and leaves of Semiliquidambar cathayensis.It is usually confused with medicinal herbs from Pterospermum heterophyllum and Dendropanax dentiger.However,they are very different in chemical composition,and should not be used as the same drug.To ensure their safety and efficacy,a method based on macroscopic and microscopic characteristics was developed to distinguish them.Methods:A total of 14 batches of Ban Fenghe samples from three species were collected from different producing areas in China.The macroscopic characteristics were examined by observing external traits.The tissue structures of transverse sections of stems and leaves,the leaf epidermis,and the powder were observed microscopically.Results:The branchlets and leaf surfaces of S.cathayensis and P.heterophyllum were hairy,especially the lower leaf surfaces of P.heterophyllum were densely covered with hairs,but those of D.dentiger were hairless.The pericyclic fibers of S.cathayensis stems were intermittently distributed in a circular shape and accompanied by stone cells,whereas those of P.heterophyllum and D.dentiger were bundled without stone cells.So stone cells and hairs were present in S.cathayensis powder,stone cells were not found in P.heterophyllum and D.dentiger powder,and hairs were not present in D.dentiger powder.The distribution sites,sizes and types of secretory tissues of these three species were also different in transverse sections of stems and leaves.Stomata on the lower epidermis of S.cathayensis leaves were paracytic,whereas those of P.heterophyllum and D.dentiger were anomocytic.Conclusion:Ban Fenghe drugs derived from S.cathayensis could readily be distinguished from those of P.heterophyllum and D.dentiger by macroscopic and microscopic features.
文摘Chinese State Councilor and Minister of National Defense Wei Fenghe gave a speech at the 18th Shangri-La Dialogue in Singapore on June 2,stating China's stance on international security cooperation.
