It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the ef...It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the effect of the NVE on these kinetic processes is not known.The total fractionations(MDFs+NVEinduced MIFs)of several representative Hg-incorporated substances were selected and calculated with ab initio calculations in this work for both equilibrium and kinetic processes.NVE-induced MIFs were calculated with scaled contact electron densities at the nucleus through systematic evaluations of their accuracy and errors using the Gaussian09 and DIRAC19 packages(named the electron density scaling method).Additionally,the NVE-induced kinetic isotope effect(KIE)of Hg isotopes are also calculated with this method for several representative Hg oxidation reactions by chlorine species.Total KIEs for 202 Hg/^(198)Hg ranging from−2.27‰to 0.96‰are obtained.Three anomalous^(202)Hg-enriched KIEs(δ^(202)Hg/^(198)Hg=0.83‰,0.94‰,and 0.96‰,)caused by the NVE are observed,which are quite different from the classical view(i.e.,light isotopes react faster than the heavy ones).The electron density scaling method we developed in this study can provide an easier way to calculate the NVE-induced KIEs for heavy isotopes and serve to better understand the fractionation mechanisms of mercury isotope systems.展开更多
The development of highly efficient and stable electrocatalysts for the hydrogen evolution reaction(HER)under alkaline media is of great importance due to its sluggish water dissociation kinetics.In this work,ultrafin...The development of highly efficient and stable electrocatalysts for the hydrogen evolution reaction(HER)under alkaline media is of great importance due to its sluggish water dissociation kinetics.In this work,ultrafine Rh nanoparticle decorated MoSe_(2)nanoflowers have been synthesized through a colloidal synthetic method.When further used as electrocatalysts for HER in alkaline media,the experimental results demonstrate that 8.2%Rh–MoSe_(2)nanoflowers exhibit excellent catalytic activity with a small overpotential of 73 mV to obtain the current density of 10 mA cm^(−2)with good stability.展开更多
Previous studies systematically characterized the structural features,digestion,and fermentation properties of Pleurotus eryngii protein and its complex with oatβ-glucan(W-PEP-OG).The results indicated that,compared ...Previous studies systematically characterized the structural features,digestion,and fermentation properties of Pleurotus eryngii protein and its complex with oatβ-glucan(W-PEP-OG).The results indicated that,compared with the protein alone,W-PEP-OG exerts more favorable modulatory effects on gut health and may improve intestinal barrier function.In this study,a co-culture model of HT-29 and Caco-2 cells was employed to simulate the small intestinal and colonic barriers,and dextran sulfate sodium(DSS)was used to induce ulcerative colitis-like injury.The protective effects of sterile-filtered fractions derived from digested and fermented W-PEP-OG(D-W and F-W)on barrier integrity were systematically evaluated,along with their regulation of gut microbial metabolites.Both D-W and F-W alleviated DSS-induced barrier damage,as evidenced by reductions in inflam-mation and oxidative stress,accompanied by upregulation of mucins(MUC2 and MUC4),goblet cell-secreted factors(TFF3 and RELMβ),and tight junction proteins(ZO-1,occludin,and claudin-1).Untargeted metab-olomic analysis revealed that W-PEP-OG could modulate gut microbial pathways involved in tryptophan metabolism,histidine metabolism,and arginine biosynthesis,thereby promoting the production of metabolites such as tryptophan,indole-3-ethanol,and histamine,previously implicated in the regulation of intestinal barrier function.These findings provide a theoretical basis for the potential application of W-PEP-OG in mitigating intestinal barrier damage associated with ulcerative colitis.展开更多
The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind ...The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.展开更多
基金This paper is supported by Chinese NSF project(42130114)the strategic priority research program(B)of CAS(XDB41000000)the pre-research Project on Civil Aerospace Technologies No.D020202 funded by Chinese National Space Administration(CNSA)。
文摘It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the effect of the NVE on these kinetic processes is not known.The total fractionations(MDFs+NVEinduced MIFs)of several representative Hg-incorporated substances were selected and calculated with ab initio calculations in this work for both equilibrium and kinetic processes.NVE-induced MIFs were calculated with scaled contact electron densities at the nucleus through systematic evaluations of their accuracy and errors using the Gaussian09 and DIRAC19 packages(named the electron density scaling method).Additionally,the NVE-induced kinetic isotope effect(KIE)of Hg isotopes are also calculated with this method for several representative Hg oxidation reactions by chlorine species.Total KIEs for 202 Hg/^(198)Hg ranging from−2.27‰to 0.96‰are obtained.Three anomalous^(202)Hg-enriched KIEs(δ^(202)Hg/^(198)Hg=0.83‰,0.94‰,and 0.96‰,)caused by the NVE are observed,which are quite different from the classical view(i.e.,light isotopes react faster than the heavy ones).The electron density scaling method we developed in this study can provide an easier way to calculate the NVE-induced KIEs for heavy isotopes and serve to better understand the fractionation mechanisms of mercury isotope systems.
基金financially supported by the National Natural Science Foundation of China(21571145,21633008)Largescale Largescale Instrument and Equipment Sharing Foundation of Wuhan University.
文摘The development of highly efficient and stable electrocatalysts for the hydrogen evolution reaction(HER)under alkaline media is of great importance due to its sluggish water dissociation kinetics.In this work,ultrafine Rh nanoparticle decorated MoSe_(2)nanoflowers have been synthesized through a colloidal synthetic method.When further used as electrocatalysts for HER in alkaline media,the experimental results demonstrate that 8.2%Rh–MoSe_(2)nanoflowers exhibit excellent catalytic activity with a small overpotential of 73 mV to obtain the current density of 10 mA cm^(−2)with good stability.
基金supported by the National Natural Science Foundation of China(No.32372324)the Key Research and Development Program of Jiangsu Province(BE2022378).
文摘Previous studies systematically characterized the structural features,digestion,and fermentation properties of Pleurotus eryngii protein and its complex with oatβ-glucan(W-PEP-OG).The results indicated that,compared with the protein alone,W-PEP-OG exerts more favorable modulatory effects on gut health and may improve intestinal barrier function.In this study,a co-culture model of HT-29 and Caco-2 cells was employed to simulate the small intestinal and colonic barriers,and dextran sulfate sodium(DSS)was used to induce ulcerative colitis-like injury.The protective effects of sterile-filtered fractions derived from digested and fermented W-PEP-OG(D-W and F-W)on barrier integrity were systematically evaluated,along with their regulation of gut microbial metabolites.Both D-W and F-W alleviated DSS-induced barrier damage,as evidenced by reductions in inflam-mation and oxidative stress,accompanied by upregulation of mucins(MUC2 and MUC4),goblet cell-secreted factors(TFF3 and RELMβ),and tight junction proteins(ZO-1,occludin,and claudin-1).Untargeted metab-olomic analysis revealed that W-PEP-OG could modulate gut microbial pathways involved in tryptophan metabolism,histidine metabolism,and arginine biosynthesis,thereby promoting the production of metabolites such as tryptophan,indole-3-ethanol,and histamine,previously implicated in the regulation of intestinal barrier function.These findings provide a theoretical basis for the potential application of W-PEP-OG in mitigating intestinal barrier damage associated with ulcerative colitis.
基金National Natural Science Fund(51675006)the project of Science and Technology Department of Shaanxi Province(2016JZ017)the Local Servicing Research Project of the Education Department of Shanxi Province(15JF007).
文摘The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.
