As the simplest hydrogen-bonded alcohol,liquid methanol has attracted intensive experimental and theoretical interest.However,theoretical investigations on this system have primarily relied on empirical intermolecular...As the simplest hydrogen-bonded alcohol,liquid methanol has attracted intensive experimental and theoretical interest.However,theoretical investigations on this system have primarily relied on empirical intermolecular force fields or ab initio molecular dynamics with semilocal density functionals.Inspired by recent studies on bulk water using increasingly accurate machine learning force fields,we report a new machine learning force field for liquid methanol with a hybrid functional revPBE0 plus dispersion correction.Molecular dynamics simulations on this machine learning force field are orders of magnitude faster than ab initio molecular dynamics simulations,yielding the radial distribution functions,selfdiffusion coefficients,and hydrogen bond network properties with very small statistical errors.The resulting structural and dynamical properties are compared well with the experimental data,demonstrating the superior accuracy of this machine learning force field.This work represents a successful step toward a first-principles description of this benchmark system and showcases the general applicability of the machine learning force field in studying liquid systems.展开更多
This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investi...This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.展开更多
We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein...We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final（S）-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.展开更多
An efficient,economical,and phosgene-free approach was developed for the preparation of l,4-dihydro-2H-3,l-benzoxazin-2-one from 2-aminobenzyl alcohol.In terms of its key features,this reaction uses the cheap and recy...An efficient,economical,and phosgene-free approach was developed for the preparation of l,4-dihydro-2H-3,l-benzoxazin-2-one from 2-aminobenzyl alcohol.In terms of its key features,this reaction uses the cheap and recyclable non-metal selenium as a catalyst instead of the noble metal palladium;carbon monoxide as a carbonylation agent instead of virulent phosgene or one of its derivatives;and oxygen as an oxidant.The selenium-catalyzed oxidative carbonylation reaction of2-aminobenzyl alcohol proceeded efficiently in a single pot in the presence of triethylamine to afford l,4-dihydro-2H-3,l-benzoxazin-2-one in 87%yield.Furthermore,the selenium catalyst was readily recovered and recycled,affording a product yield of 80%after five cycles.展开更多
Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase ...Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase of methanol-water （55：45） with a flow rate at 1.0 mL·min^-1. The detection wavelength was 258 nm. Results Under the chromatographic condition, the peaks of 1-phenylpropanol and its related impurities separated completely; noninterference between the principal agent and adjuvants in preparations was performed. The calibration curve was linear over the range of 250 - 750μg·mL^-1 with the correlation coefficient of 0. 999 9. The average recovery was 100.2% （ RSD = 1.35% ）. Conclusion This method is simple, rapid, accurate, specific, and can be used to detect the content and related compounds of phenylpropanol in its raw material and preparations.展开更多
[Objective]The aim was to explore the active compound of Morus alba leaves with the analysis of active components of hexane extractives of M.alba leaves.[Method]Antibacterial assays of hexane extractives of M.alba lea...[Objective]The aim was to explore the active compound of Morus alba leaves with the analysis of active components of hexane extractives of M.alba leaves.[Method]Antibacterial assays of hexane extractives of M.alba leaves were done and the volatile components of hexane extractives of M.alba leaves with the strongest antibacterial activity were analyzed by gas chromatography-mass spectrometry（GC-MS）.[Result]The results of inhibitory effect of hexane extractives of M.alba leaves on Staphylococcus aureus and Escherichia coli showed that hexane extractives of M.alba leaves collected in June,July and August had antibacterial activity against S.aureus and had no antibacterial effect against E.coli.Furthermore,hexane extractives of M.alba leaves collected in June had the strongest antibacterial activity against S.aureus（inhibition diameter 10.95 mm）.The hexane extractives of M.alba leaves collected in June was analyzed by GC-MS,the main volatile components were tetradecane（16.76%）,dodecane（13.20%）,diisobutyl phthalate（10.26%）,decane（9.10%）,hexadecane（8.71%）,linolenyl alcohol（7.25%）,octadecane（5.88%）,eicosane（3.26%）,dibutyl phthalate（2.59%）.[Conclusion]Linolenyl alcohol was the potential antibacterial compound.展开更多
基金supported by the CAS Project for Young Scientists in Basic Research(YSBR-005)the National Natural Science Foundation of China(22325304,22221003 and 22033007)We acknowledge the Supercomputing Center of USTC,Hefei Advanced Computing Center,Beijing PARATERA Tech Co.,Ltd.,for providing high-performance computing services。
文摘As the simplest hydrogen-bonded alcohol,liquid methanol has attracted intensive experimental and theoretical interest.However,theoretical investigations on this system have primarily relied on empirical intermolecular force fields or ab initio molecular dynamics with semilocal density functionals.Inspired by recent studies on bulk water using increasingly accurate machine learning force fields,we report a new machine learning force field for liquid methanol with a hybrid functional revPBE0 plus dispersion correction.Molecular dynamics simulations on this machine learning force field are orders of magnitude faster than ab initio molecular dynamics simulations,yielding the radial distribution functions,selfdiffusion coefficients,and hydrogen bond network properties with very small statistical errors.The resulting structural and dynamical properties are compared well with the experimental data,demonstrating the superior accuracy of this machine learning force field.This work represents a successful step toward a first-principles description of this benchmark system and showcases the general applicability of the machine learning force field in studying liquid systems.
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2023yjrc51)the National Natural Science Foundation of China(22172184)+2 种基金the Foundation of State Key Laboratory of Coal Conversion(J24-25-603)the Fundamental Research Project of ICC-CAS(SCJC-DT-2023-01)Weiqiao-UCAS Special Projects on Low-Carbon Technology Development(GYY-DTFZ-2022-015)。
文摘This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA11030404),the Key Project from Chinese Academy of Sciences(KGZD-EW-606)the National Natural Science Foundation of China(21302199)Guangzhou Science and Technology Plan Projects(201510010012)
文摘We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final（S）-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(IRT1061)the Program for Innovative Research Team in Science and Technology in University of Henan Province(15IRTSTHN003)+1 种基金the Young Backbone Teachers Training Fund of the Education Department of Henan Province(2013GGJS-059)Henan Normal University(2011-8)
文摘An efficient,economical,and phosgene-free approach was developed for the preparation of l,4-dihydro-2H-3,l-benzoxazin-2-one from 2-aminobenzyl alcohol.In terms of its key features,this reaction uses the cheap and recyclable non-metal selenium as a catalyst instead of the noble metal palladium;carbon monoxide as a carbonylation agent instead of virulent phosgene or one of its derivatives;and oxygen as an oxidant.The selenium-catalyzed oxidative carbonylation reaction of2-aminobenzyl alcohol proceeded efficiently in a single pot in the presence of triethylamine to afford l,4-dihydro-2H-3,l-benzoxazin-2-one in 87%yield.Furthermore,the selenium catalyst was readily recovered and recycled,affording a product yield of 80%after five cycles.
文摘Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase of methanol-water （55：45） with a flow rate at 1.0 mL·min^-1. The detection wavelength was 258 nm. Results Under the chromatographic condition, the peaks of 1-phenylpropanol and its related impurities separated completely; noninterference between the principal agent and adjuvants in preparations was performed. The calibration curve was linear over the range of 250 - 750μg·mL^-1 with the correlation coefficient of 0. 999 9. The average recovery was 100.2% （ RSD = 1.35% ）. Conclusion This method is simple, rapid, accurate, specific, and can be used to detect the content and related compounds of phenylpropanol in its raw material and preparations.
基金Supported by the Forestry Department of Heilongjiang Province Science and Technology Promotion Project(01043208003)the Project of Science and Technology Department of Heilongjiang Province(LC07C27)~~
文摘[Objective]The aim was to explore the active compound of Morus alba leaves with the analysis of active components of hexane extractives of M.alba leaves.[Method]Antibacterial assays of hexane extractives of M.alba leaves were done and the volatile components of hexane extractives of M.alba leaves with the strongest antibacterial activity were analyzed by gas chromatography-mass spectrometry（GC-MS）.[Result]The results of inhibitory effect of hexane extractives of M.alba leaves on Staphylococcus aureus and Escherichia coli showed that hexane extractives of M.alba leaves collected in June,July and August had antibacterial activity against S.aureus and had no antibacterial effect against E.coli.Furthermore,hexane extractives of M.alba leaves collected in June had the strongest antibacterial activity against S.aureus（inhibition diameter 10.95 mm）.The hexane extractives of M.alba leaves collected in June was analyzed by GC-MS,the main volatile components were tetradecane（16.76%）,dodecane（13.20%）,diisobutyl phthalate（10.26%）,decane（9.10%）,hexadecane（8.71%）,linolenyl alcohol（7.25%）,octadecane（5.88%）,eicosane（3.26%）,dibutyl phthalate（2.59%）.[Conclusion]Linolenyl alcohol was the potential antibacterial compound.
