In order to better blend green plum wine and study aromatic components of green plum wine,a qualitative analysis on aromatic components of soaked base liquor,green plum soaked wine,green plum juice,and fermented wine ...In order to better blend green plum wine and study aromatic components of green plum wine,a qualitative analysis on aromatic components of soaked base liquor,green plum soaked wine,green plum juice,and fermented wine of green plum juice by Head Space Solid-phase Microextraction( HS-SPME) and Gas Chromatograph Mass Spectrometer( GC-MS) was studied in this paper. Experiment results indicated that14,32,17,and 46 kinds of aromatic components were identified respectively from four samples. Different aromatic components determined the special flavor and taste of green plum wine. Unique aromatic components generated in soaking process include benzaldehyde,1-butanol,2-methyl-,S-(-),benzoic acid ethyl ester,and 5-( hydroxymethyl). Special aromatic components in green plum juice were furfural,phenylethyl alcohol,and benzyl alcohol. The aromatic components in fermented wine of green plum juice mainly included phenylethyl alcohol( 6. 941%,relative content of peak area,same below),1-butanol,3-methyl-( 6. 940%),octanoic acid,ethyl ester( 3. 734%),decanoic acid,ethyl ester( 2. 590%),hexanoic acid,ethyl ester( 2. 479%),ethyl 9-decenoate( 2. 080%),and 5-hydroxymethyl( 1. 756%). This study was expected to provide scientific basis and data reference for quality improvement of green plum wine.展开更多
Hierarchically porous architecture of ir on-nitroge n-carb on(Fe-N-C)for oxyge n reducti on reaction(ORR)is highly desired towards efficient mass transfer in the fuel cell device manner.Herein,we reported a binary lig...Hierarchically porous architecture of ir on-nitroge n-carb on(Fe-N-C)for oxyge n reducti on reaction(ORR)is highly desired towards efficient mass transfer in the fuel cell device manner.Herein,we reported a binary ligand strategy to prepare zeolitic imidazolate frameworks(ZIFs)-derived precursors,wherein the addition of secondary ligand endows precursors with the capabilities to transform into porously interweaved encapsulation-nanotubes structured composites after calcination.The optimal catalyst,i.e.,termed as Fe_(6)-M/C-3,exhibits excellent durability with 88.8%current retention after 50,000 seconds in 0.1 M HClO_(4)solution by virtue of nanoparticles-encapsulation features,which is more positive than the benchmark commercial 20 wt%Pt/C catalyst.Moreover,a promising maximum power density of Fe_(6)-M/C-3 as cathode catalyst was also dem on strated in proton exchange membrane fuel cells(PEMFCs)measurements.Therefore,this binary ligand approach to the fabrication of hierarchically porous structures would also have significant implications for various other electrochemical reactions.展开更多
2D material of graphene has inspired huge interest in fabricating of solid state gas sensors.In this work,epitaxial graphene,quasi-free-standing graphene,and CVD epitaxial graphene samples on SiC substrates are used t...2D material of graphene has inspired huge interest in fabricating of solid state gas sensors.In this work,epitaxial graphene,quasi-free-standing graphene,and CVD epitaxial graphene samples on SiC substrates are used to fabricate gas sensors.Defects are introduced into graphene using SF6 plasma treatment to improve the performance of the gas sensors.The epitaxial graphene shows high sensitivity to NO2 with response of 105.1%to 4 ppm NO2 and detection limit of 1 ppb.The higher sensitivity of epitaxial graphene compared to quasi-free-standing graphene,and CVD epitaxial graphene was found to be related to the different doping types of the samples.展开更多
Over the years,natural gas hydrates(NGHs)have attracted significant attention as an emerging energy resource.Microfluidics is a novel technology used to observe the behaviour of NGHs in microchannels directly and has ...Over the years,natural gas hydrates(NGHs)have attracted significant attention as an emerging energy resource.Microfluidics is a novel technology used to observe the behaviour of NGHs in microchannels directly and has been applied to hydrates.Gas hydrate distributions and phase transitions are key parameters for exploitation and application.In this paper,advances in related research with microfluidics-based technology are reviewed,including the hydrate phase transition process and its mechanism of influence.Hydrate formation and decomposition directly influence the efficiency and sustainability of exploitation.In addition,studies of the hydrate phase transition provide basic data for future commercial exploitation.Moreover,extended applications,further developments and potential improvements in microfluidic techniques are also discussed.We believe that with an improved understanding of the hydrate phase transition mechanism,commercial exploitation of hydrates can be expected soon.展开更多
The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[b]quinoline-iron(II)chlorides(aryl=2,6-Me_(2)C_(6)H_(3) Fe1;2,6-Et_(2)C_(6)H_(3) Fe_(2);2,6-i-Pr_(2)C_(6)H_(3) Fe_(3);2,4,6-Me3C_(6)H_(2) Fe4;and 2,6-Et_(2)-4...The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[b]quinoline-iron(II)chlorides(aryl=2,6-Me_(2)C_(6)H_(3) Fe1;2,6-Et_(2)C_(6)H_(3) Fe_(2);2,6-i-Pr_(2)C_(6)H_(3) Fe_(3);2,4,6-Me3C_(6)H_(2) Fe4;and 2,6-Et_(2)-4-Me_(2)C_(6)H_(2) Fe_(5))have been prepared in good yield by a straightforward one-pot reaction of 2,3,7,8,9,10-hexahydro-1H-cyclohepta[b]quinoline-4,6-dione,FeCl_(2)·4H_(2)O,and the appropriate aniline in acetic acid.All ferrous complexes have been characterized by elemental analysis and FT-IR spectroscopy.In addition,the structure of Fe_(3) has been determined by single crystal X-ray diffraction,which showed the iron center to adopt a distorted square pyramidal geometry with the saturated sections of the fused six-and sevenmembered carbocycles to be cis-configured.In combination with either MAO or MMAO,Fe1–Fe5 exhibited exceptionally high activities for ethylene polymerization(up to 15:86×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 40℃(MMAO)and 9:60×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 60℃(MAO))and produced highly linear polyethylene(HLPE,Tm≥128℃)with a wide range in molecular weights;in general,the MMAO-promoted polymerizations were more active.Irrespective of the cocatalyst employed,the 2,6-Me_(2)-substituted Fe1 and Fe4 proved the most active while the more sterically hindered 2,6-i-Pr_(2) Fe_(3) the least but afforded the highest molecular weight polyethylene(Mw:65.6–72.6 kg mol^(-1)).Multinuclear NMR spectroscopic analysis of the polymer formed using Fe4/MMAO at 40℃ showed a preference for fully saturated chain ends with a broad bimodal distribution a feature of the GPC trace(Mw/Mn=13:4).By contrast,using Fe4/MAO at 60℃ a vinyl-terminated polymer of lower molecular weight(Mw=14:2 kg mol^(−1))was identified that exhibited a unimodal distribution(Mw/Mn=3:8).Moreover,the amount of aluminoxane cocatalyst employed,temperature,and run time were also found to be influential on the modality of the polymer.展开更多
基金Supported by Talent Introduction Project of Sichuan University of Science&Engineering(2012RC142015RC14)
文摘In order to better blend green plum wine and study aromatic components of green plum wine,a qualitative analysis on aromatic components of soaked base liquor,green plum soaked wine,green plum juice,and fermented wine of green plum juice by Head Space Solid-phase Microextraction( HS-SPME) and Gas Chromatograph Mass Spectrometer( GC-MS) was studied in this paper. Experiment results indicated that14,32,17,and 46 kinds of aromatic components were identified respectively from four samples. Different aromatic components determined the special flavor and taste of green plum wine. Unique aromatic components generated in soaking process include benzaldehyde,1-butanol,2-methyl-,S-(-),benzoic acid ethyl ester,and 5-( hydroxymethyl). Special aromatic components in green plum juice were furfural,phenylethyl alcohol,and benzyl alcohol. The aromatic components in fermented wine of green plum juice mainly included phenylethyl alcohol( 6. 941%,relative content of peak area,same below),1-butanol,3-methyl-( 6. 940%),octanoic acid,ethyl ester( 3. 734%),decanoic acid,ethyl ester( 2. 590%),hexanoic acid,ethyl ester( 2. 479%),ethyl 9-decenoate( 2. 080%),and 5-hydroxymethyl( 1. 756%). This study was expected to provide scientific basis and data reference for quality improvement of green plum wine.
基金supported by the National Key Research and Development Program of China (2019YFA0210300)the NSF of China (21922802)+3 种基金the Beijing Natural Science Foundation (JQ19007)Talent cultivation and open project (OIC- 201801007) of State Key Laboratory of Organic-Inorganic Composites“Double-First-Class” construction projects (XK180301, XK180402)Distinguished Scientist Program at BUCT (buctylkxj02)。
文摘Hierarchically porous architecture of ir on-nitroge n-carb on(Fe-N-C)for oxyge n reducti on reaction(ORR)is highly desired towards efficient mass transfer in the fuel cell device manner.Herein,we reported a binary ligand strategy to prepare zeolitic imidazolate frameworks(ZIFs)-derived precursors,wherein the addition of secondary ligand endows precursors with the capabilities to transform into porously interweaved encapsulation-nanotubes structured composites after calcination.The optimal catalyst,i.e.,termed as Fe_(6)-M/C-3,exhibits excellent durability with 88.8%current retention after 50,000 seconds in 0.1 M HClO_(4)solution by virtue of nanoparticles-encapsulation features,which is more positive than the benchmark commercial 20 wt%Pt/C catalyst.Moreover,a promising maximum power density of Fe_(6)-M/C-3 as cathode catalyst was also dem on strated in proton exchange membrane fuel cells(PEMFCs)measurements.Therefore,this binary ligand approach to the fabrication of hierarchically porous structures would also have significant implications for various other electrochemical reactions.
基金supported by the National Natural Science Foundation of China (61674131 and 61306006)
文摘2D material of graphene has inspired huge interest in fabricating of solid state gas sensors.In this work,epitaxial graphene,quasi-free-standing graphene,and CVD epitaxial graphene samples on SiC substrates are used to fabricate gas sensors.Defects are introduced into graphene using SF6 plasma treatment to improve the performance of the gas sensors.The epitaxial graphene shows high sensitivity to NO2 with response of 105.1%to 4 ppm NO2 and detection limit of 1 ppb.The higher sensitivity of epitaxial graphene compared to quasi-free-standing graphene,and CVD epitaxial graphene was found to be related to the different doping types of the samples.
基金supported by the National Natural Science Foundation of China(Grant 52176057)supported by the Key Laboratory of Gas Hydrate,Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences(Grant E129kf1101)+1 种基金the Fundamental Research Funds for the Central Universities(DUT22LAB103)Shenzhen Science and Technology Planning Project(JCYJ20220530113011027,JCYJ20220818095605012).
文摘Over the years,natural gas hydrates(NGHs)have attracted significant attention as an emerging energy resource.Microfluidics is a novel technology used to observe the behaviour of NGHs in microchannels directly and has been applied to hydrates.Gas hydrate distributions and phase transitions are key parameters for exploitation and application.In this paper,advances in related research with microfluidics-based technology are reviewed,including the hydrate phase transition process and its mechanism of influence.Hydrate formation and decomposition directly influence the efficiency and sustainability of exploitation.In addition,studies of the hydrate phase transition provide basic data for future commercial exploitation.Moreover,extended applications,further developments and potential improvements in microfluidic techniques are also discussed.We believe that with an improved understanding of the hydrate phase transition mechanism,commercial exploitation of hydrates can be expected soon.
基金This work was supported by the National Natural Science Foundation of China(No.21871275).GAS thanks the Chinese Academy of Sciences for a Visiting Fellowship.
文摘The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[b]quinoline-iron(II)chlorides(aryl=2,6-Me_(2)C_(6)H_(3) Fe1;2,6-Et_(2)C_(6)H_(3) Fe_(2);2,6-i-Pr_(2)C_(6)H_(3) Fe_(3);2,4,6-Me3C_(6)H_(2) Fe4;and 2,6-Et_(2)-4-Me_(2)C_(6)H_(2) Fe_(5))have been prepared in good yield by a straightforward one-pot reaction of 2,3,7,8,9,10-hexahydro-1H-cyclohepta[b]quinoline-4,6-dione,FeCl_(2)·4H_(2)O,and the appropriate aniline in acetic acid.All ferrous complexes have been characterized by elemental analysis and FT-IR spectroscopy.In addition,the structure of Fe_(3) has been determined by single crystal X-ray diffraction,which showed the iron center to adopt a distorted square pyramidal geometry with the saturated sections of the fused six-and sevenmembered carbocycles to be cis-configured.In combination with either MAO or MMAO,Fe1–Fe5 exhibited exceptionally high activities for ethylene polymerization(up to 15:86×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 40℃(MMAO)and 9:60×10^(6) g(PE)mol^(−1)(Fe)h^(−1) at 60℃(MAO))and produced highly linear polyethylene(HLPE,Tm≥128℃)with a wide range in molecular weights;in general,the MMAO-promoted polymerizations were more active.Irrespective of the cocatalyst employed,the 2,6-Me_(2)-substituted Fe1 and Fe4 proved the most active while the more sterically hindered 2,6-i-Pr_(2) Fe_(3) the least but afforded the highest molecular weight polyethylene(Mw:65.6–72.6 kg mol^(-1)).Multinuclear NMR spectroscopic analysis of the polymer formed using Fe4/MMAO at 40℃ showed a preference for fully saturated chain ends with a broad bimodal distribution a feature of the GPC trace(Mw/Mn=13:4).By contrast,using Fe4/MAO at 60℃ a vinyl-terminated polymer of lower molecular weight(Mw=14:2 kg mol^(−1))was identified that exhibited a unimodal distribution(Mw/Mn=3:8).Moreover,the amount of aluminoxane cocatalyst employed,temperature,and run time were also found to be influential on the modality of the polymer.