Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,w...Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction.展开更多
Eight darmarane-type saponins,named as sanchirhinoside D(1),3β,6 α-20(S)-6,20-bis(β-D-glucopyranosyloxy)-3-hydroxy dammar-24-en-12-one(2),20(R)-ginsenoside Rg3(3),ginsenosides F2(4)and Rd(5),gypenoside XVII(6),gins...Eight darmarane-type saponins,named as sanchirhinoside D(1),3β,6 α-20(S)-6,20-bis(β-D-glucopyranosyloxy)-3-hydroxy dammar-24-en-12-one(2),20(R)-ginsenoside Rg3(3),ginsenosides F2(4)and Rd(5),gypenoside XVII(6),ginsenosides Rb1(7)and ginsenoside V(8)were isolated from the 70%ethanol extract of Panax notoginseng roots by silica gel,octadecyl silane(ODS)column chromatography and HPLC,and identified by chemical and physical methods,especially by spectral analysis.Among them,1 was a new compound and 2 was a new natural product.展开更多
The category of＂customs,＂ or the Song dynasty in writing local histories was important for the literati of It covers local practices of festival rituals, weddings and funerals, rites for passage into adulthood, sacr...The category of＂customs,＂ or the Song dynasty in writing local histories was important for the literati of It covers local practices of festival rituals, weddings and funerals, rites for passage into adulthood, sacrificial rites, and the like. The main purpose behind the literati＇s efforts to record /bngsu was not to acknowledge local variations but to censor local customs and transform society. This paper looks at these type of texts as a discourse that is meant to promote the correct, standard performance of rites and suppress those deemed improper. It uses boat racing in Song records of/bngsu as a case study to illustrate how the imperial spectacle of boat racing in spring was propagated and how the linkage between the death anniversary of Qu Yuan and Duanwu were reinforced. Meanwhile, the popular ritual of boat racing during the summer, which bore distinct violent and shamanic attributes, was strongly criticised. Through these efforts by the literati, a normative discourse of the boat-racing ritual was repeated and reinforced in the fengsu recording展开更多
Humic-like substances(HULIS),a class of macromolecular photosensitizers,are major components of light-absorbing aerosols in the atmosphere.Due to the amphiphilic nature of HULIS,they tend to appear at the air-water in...Humic-like substances(HULIS),a class of macromolecular photosensitizers,are major components of light-absorbing aerosols in the atmosphere.Due to the amphiphilic nature of HULIS,they tend to appear at the air-water interface of atmospheric water.However,there have been limited studies on the photosensitized chemistry of HULIS at the air-water interface owing to the lack of methods with high interface selectivity.Here,a unique field-induced droplet ionization mass spectrometry(FIDI-MS)technique was used to investigate the photosensitized chemistry of several samples at the air-water interface.These samples include commercially available humic acid and the PM_(2.5)sample collected during Beijing′s severe winter haze in December 2016.Ultrahigh-resolution Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS)was also applied to analyze the atomic compositions,the degree of unsaturation and the aromaticity of these samples.Both TypeⅠand TypeⅡphotosensitized oxidation pathways were observed,which were postulated to be dictated by the packing density of the molecules at the air-water interface.These findings reveal that the photosensitization of HULIS at the air-water interface contributes greatly to the formation of atmospheric aerosols,further advancing our understanding of the important roles played by photosensitized chemistry in the atmosphere.展开更多
基金financially supported by the National Natural Science Foundation of China (21968020)the Natural Science Foundation of Inner Mongolia (2022MS02011 and 2023MS02014)+1 种基金the Science and Technology Projects of China Northern Rare Earth (BFXT-2022-D-0023)the Open Research Subject of Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control (2021Z01)。
文摘Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction.
基金supported by the National Natural Science Foundation of China(81303182,81173523)the National Major Scientific and Technological Special Project for“Significant New Drugs Development”(2018ZX09734-002).
基金supported by Program for National Natural Science Foundation of China(NSFC81202995)New Century Excellent Talents in University(NCET-10-0958,NCET-12-1069)+1 种基金Applied Basic and Advanced Research Program of Tianjin(10ZCKFSY09300)Important Drug Development Fund,Ministry of Science and Technology of China(2011ZX09307-002-01).
文摘Eight darmarane-type saponins,named as sanchirhinoside D(1),3β,6 α-20(S)-6,20-bis(β-D-glucopyranosyloxy)-3-hydroxy dammar-24-en-12-one(2),20(R)-ginsenoside Rg3(3),ginsenosides F2(4)and Rd(5),gypenoside XVII(6),ginsenosides Rb1(7)and ginsenoside V(8)were isolated from the 70%ethanol extract of Panax notoginseng roots by silica gel,octadecyl silane(ODS)column chromatography and HPLC,and identified by chemical and physical methods,especially by spectral analysis.Among them,1 was a new compound and 2 was a new natural product.
文摘The category of＂customs,＂ or the Song dynasty in writing local histories was important for the literati of It covers local practices of festival rituals, weddings and funerals, rites for passage into adulthood, sacrificial rites, and the like. The main purpose behind the literati＇s efforts to record /bngsu was not to acknowledge local variations but to censor local customs and transform society. This paper looks at these type of texts as a discourse that is meant to promote the correct, standard performance of rites and suppress those deemed improper. It uses boat racing in Song records of/bngsu as a case study to illustrate how the imperial spectacle of boat racing in spring was propagated and how the linkage between the death anniversary of Qu Yuan and Duanwu were reinforced. Meanwhile, the popular ritual of boat racing during the summer, which bore distinct violent and shamanic attributes, was strongly criticised. Through these efforts by the literati, a normative discourse of the boat-racing ritual was repeated and reinforced in the fengsu recording
基金the National Natural Science Foundation of China(42221001)the National Natural Science Foundation of China(22325402,22174073)+4 种基金the National Key R&D Program of China(2023YFE0124200)the Natural Science Foundation of Tianjin City(21JCJQJC00010)the Natural Science Foundation of Tianjin City(23ZYJDSS00030)the Nankai Cangzhou Chemistry(NCC)Fund(NCC2022PY05)the Haihe Laboratory of Sustainable Chemical Transformations and the Frontiers Science Center for New Organic Matter at Nankai University(63181206)。
文摘Humic-like substances(HULIS),a class of macromolecular photosensitizers,are major components of light-absorbing aerosols in the atmosphere.Due to the amphiphilic nature of HULIS,they tend to appear at the air-water interface of atmospheric water.However,there have been limited studies on the photosensitized chemistry of HULIS at the air-water interface owing to the lack of methods with high interface selectivity.Here,a unique field-induced droplet ionization mass spectrometry(FIDI-MS)technique was used to investigate the photosensitized chemistry of several samples at the air-water interface.These samples include commercially available humic acid and the PM_(2.5)sample collected during Beijing′s severe winter haze in December 2016.Ultrahigh-resolution Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS)was also applied to analyze the atomic compositions,the degree of unsaturation and the aromaticity of these samples.Both TypeⅠand TypeⅡphotosensitized oxidation pathways were observed,which were postulated to be dictated by the packing density of the molecules at the air-water interface.These findings reveal that the photosensitization of HULIS at the air-water interface contributes greatly to the formation of atmospheric aerosols,further advancing our understanding of the important roles played by photosensitized chemistry in the atmosphere.
