A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides...A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.展开更多
Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum ...Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost(TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68% and 25.40% saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second,temperature control tray locations are obtained according to the sensitivity criterion and singular value decomposition(SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Finally, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor controllability despite of a little bit of economy.展开更多
The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of stand...The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of standard scattering problems[J.Chem.Phys.150,164101(2019)].Here,we study how reliable populations of both adiabatic and diabatic states can be interpreted from BCSH trajectories.Using exact quantum solutions and FSSH results as references,we investigate a series of one-dimensional two-level scattering models and illustrate that excellent timedependent populations can be obtained by BCSH.Especially,we show that different trajectory analysis strategies produce noticeable differences in different representations.Namely,the method based on active states performs better to get populations of adiabatic states,while the method based on wavefunctions produces more reliable results for populations of diabatic states.展开更多
Tetra-coordinated fluoroboron compounds have garnered significant attention in organic light-emitting diodes(OLEDs)due to their remarkable optoelectronic properties and high chemical stability.However,the design of no...Tetra-coordinated fluoroboron compounds have garnered significant attention in organic light-emitting diodes(OLEDs)due to their remarkable optoelectronic properties and high chemical stability.However,the design of novel tetra-coordinated fluoroboron-based blue thermally activated delayed fluorescence(TADF)materials with excellent external quantum efficiency(EQE)remains crucial.In this study,a novel tetra-coordinated difluoroboron-based blue TADF material with 3,6-diphenylcarbazole donor and 2-(4-phenylpyridin-2-yl)phenolate difluoroboron acceptor molecular skeleton has been designed and synthesized.Benefiting from the larger dihedral angle(68.0°)between the donor and acceptor moieties,the compound m-PhCz-BF2 exhibited a smaller singlet-triplet energy splitting(ΔE_(ST))value of 0.043 eV.As a result,a sky-blue emission with peak wavelengths of 491 and 487 nm and photoluminescence quantum yields(PLQY)of 93%and 99%were obtained in solution and doped film,respectively.Additionally,the m-PhCz-BF2 doped OLED demonstrated sky-blue electroluminescence(Commission Internationale de l'éclairage,CIE_(y)≤0.33)and a high peak EQE of 27.4%with maximum brightness of 17,493 cd/m~2.Notably,these devices also achieved a high current efficiency of 62.5 cd/A and a power efficiency of 49.4 lm/W.These remarkable performances indicate that the m-PhCz-BF2 has the potential to function as a highly efficient TADF dopant for the fabrication of sky-blue OLEDs.展开更多
The publication of several high-quality genomes has contributed greatly to clarifying the evolution of citrus.However,due to their complex genetic backgrounds,the origins and evolution of many citrus species remain un...The publication of several high-quality genomes has contributed greatly to clarifying the evolution of citrus.However,due to their complex genetic backgrounds,the origins and evolution of many citrus species remain unclear.We assembled de novo the 294-Mbp chromosome-level genome of a more than200-year-old primitive papeda(DYC002).Comparison between the two sets of homologous chromosomes of the haplotype-resolved genome revealed 1.2%intragenomic variations,including 1.75 million SNPs,149,471 insertions and 154,215 deletions.Using this genome as a reference,we resequenced and performed population and phylogenetic analyses of378 representative citrus accessions.Our study confirmed that the primary origin center of core Citrus species is in South China,particularly in the Himalaya-Hengduan Mountains.Papeda species are an ancient Citrus type compared with C.ichangensis.We found that the evolution of the Citrus genus followed two radiations through two routes(to East China and Southeast Asia)along river systems.Evidence for the origin and evolution of some individual citrus species was provided.Papeda probably played an important role in the origins of Australian finger lime,citrons,Honghe papeda and pummelos;Ichang papeda originated from Yuanjiang city of Yunnan Province,China,and C.mangshanensis has a close relationship with kumquat and Ichang papeda.Moreover,the Hunan and Guangdong Provinces of China are predicted to be the origin center of mandarin,sweet orange and sour orange.Additionally,our study revealed that fruit bitterness was significantly selected against during citrus domestication.Taken together,this study provides new insight into the origin and evolution of citrus species and may serve as a valuable genomic resource for citrus breeding and improvement.展开更多
基金The study was financially supported by the National Science and Technology Support Program of China(Grant No.2013BAD16B08).
文摘A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.
文摘Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost(TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68% and 25.40% saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second,temperature control tray locations are obtained according to the sensitivity criterion and singular value decomposition(SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Finally, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor controllability despite of a little bit of economy.
基金supported by the National Natural Science Foundation of China(No.21922305 and No.21873080)。
文摘The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of standard scattering problems[J.Chem.Phys.150,164101(2019)].Here,we study how reliable populations of both adiabatic and diabatic states can be interpreted from BCSH trajectories.Using exact quantum solutions and FSSH results as references,we investigate a series of one-dimensional two-level scattering models and illustrate that excellent timedependent populations can be obtained by BCSH.Especially,we show that different trajectory analysis strategies produce noticeable differences in different representations.Namely,the method based on active states performs better to get populations of adiabatic states,while the method based on wavefunctions produces more reliable results for populations of diabatic states.
基金supported by the National Natural Science Foundation of China (22178319,22138011)。
文摘Tetra-coordinated fluoroboron compounds have garnered significant attention in organic light-emitting diodes(OLEDs)due to their remarkable optoelectronic properties and high chemical stability.However,the design of novel tetra-coordinated fluoroboron-based blue thermally activated delayed fluorescence(TADF)materials with excellent external quantum efficiency(EQE)remains crucial.In this study,a novel tetra-coordinated difluoroboron-based blue TADF material with 3,6-diphenylcarbazole donor and 2-(4-phenylpyridin-2-yl)phenolate difluoroboron acceptor molecular skeleton has been designed and synthesized.Benefiting from the larger dihedral angle(68.0°)between the donor and acceptor moieties,the compound m-PhCz-BF2 exhibited a smaller singlet-triplet energy splitting(ΔE_(ST))value of 0.043 eV.As a result,a sky-blue emission with peak wavelengths of 491 and 487 nm and photoluminescence quantum yields(PLQY)of 93%and 99%were obtained in solution and doped film,respectively.Additionally,the m-PhCz-BF2 doped OLED demonstrated sky-blue electroluminescence(Commission Internationale de l'éclairage,CIE_(y)≤0.33)and a high peak EQE of 27.4%with maximum brightness of 17,493 cd/m~2.Notably,these devices also achieved a high current efficiency of 62.5 cd/A and a power efficiency of 49.4 lm/W.These remarkable performances indicate that the m-PhCz-BF2 has the potential to function as a highly efficient TADF dopant for the fabrication of sky-blue OLEDs.
基金supported by the China Agriculture Research System(CARS-Citrus),Fundamental Research Funds for the Central Universities(Grant No.SWU120021)the National Natural Science Foundation of China(Nos.32060664,31901995)funds from Fujian Agriculture and Forestry University,and Fundamental Research Funds for the Central Universities(SWU-XDJH202308)。
文摘The publication of several high-quality genomes has contributed greatly to clarifying the evolution of citrus.However,due to their complex genetic backgrounds,the origins and evolution of many citrus species remain unclear.We assembled de novo the 294-Mbp chromosome-level genome of a more than200-year-old primitive papeda(DYC002).Comparison between the two sets of homologous chromosomes of the haplotype-resolved genome revealed 1.2%intragenomic variations,including 1.75 million SNPs,149,471 insertions and 154,215 deletions.Using this genome as a reference,we resequenced and performed population and phylogenetic analyses of378 representative citrus accessions.Our study confirmed that the primary origin center of core Citrus species is in South China,particularly in the Himalaya-Hengduan Mountains.Papeda species are an ancient Citrus type compared with C.ichangensis.We found that the evolution of the Citrus genus followed two radiations through two routes(to East China and Southeast Asia)along river systems.Evidence for the origin and evolution of some individual citrus species was provided.Papeda probably played an important role in the origins of Australian finger lime,citrons,Honghe papeda and pummelos;Ichang papeda originated from Yuanjiang city of Yunnan Province,China,and C.mangshanensis has a close relationship with kumquat and Ichang papeda.Moreover,the Hunan and Guangdong Provinces of China are predicted to be the origin center of mandarin,sweet orange and sour orange.Additionally,our study revealed that fruit bitterness was significantly selected against during citrus domestication.Taken together,this study provides new insight into the origin and evolution of citrus species and may serve as a valuable genomic resource for citrus breeding and improvement.
