Interdigitated back contact(IBC) solar cells can achieve a very high efficiency due to its less optical losses. But IBC solar cells demand for high quality passivation of the front surface. In this paper, a polycrysta...Interdigitated back contact(IBC) solar cells can achieve a very high efficiency due to its less optical losses. But IBC solar cells demand for high quality passivation of the front surface. In this paper, a polycrystalline silicon/SiO_2 stack structure as front surface field to passivate the front surface of IBC solar cells is proposed. The passivation quality of this structure is investigated by two dimensional simulations. Polycrystalline silicon layer and SiO_2 layer are optimized to get the best passivation quality of the IBC solar cell. Simulation results indicate that the doping level of polycrystalline silicon should be high enough to allow a very thin polycrystalline silicon layer to ensure an effective passivation and small optical losses at the same time. The thickness of SiO_2 should be neither too thin nor too thick, and the optimal thickness is 1.2 nm.Furthermore, the lateral transport properties of electrons are investigated, and the simulation results indicate that a high doping level and conductivity of polycrystalline silicon can improve the lateral transportation of electrons and then the cell performance.展开更多
Poly(3,4-ethylenedioxythiophene)(PEDOT)has proved its quite competitive thermoelectric properties in flexible electronics with its excellent electrical and mechanical properties.Since the early discovery of PEDOT,cons...Poly(3,4-ethylenedioxythiophene)(PEDOT)has proved its quite competitive thermoelectric properties in flexible electronics with its excellent electrical and mechanical properties.Since the early discovery of PEDOT,considerable experimental progress has been achieved in optimizing and improving the thermoelectric properties as a promising organic thermoelectric material(OTE).Among them,theoretical research has made significant contributions to its development.Here the basic physics of conductive PEDOT are reviewed based on the combination of theory and experiment.The purpose is to provide a new insight into the development of PEDOT,so as to effectively design and preparation of advanced thermoelectric PEDOT material in the future.展开更多
The ground state geometries, frontier molecular orbital properties, and absorption properties of 4,4′-(ethane-1,2-diylbis(oxy))dibenzaldehyde (EDO-DBDHD) and its polymorph have been studied theoretically. The density...The ground state geometries, frontier molecular orbital properties, and absorption properties of 4,4′-(ethane-1,2-diylbis(oxy))dibenzaldehyde (EDO-DBDHD) and its polymorph have been studied theoretically. The density functional theory (DFT) method was employed to optimize the ground state geometries, and theoretical data reveal that EDO-DBDHD features the planar molecular conformations, in contrast to V-shaped structures of its polymorph, which agrees with the experimental data. Additionally, the absorption spectra of both compounds were predicted using time-dependent density functional theory (TDDFT). The calculated results show that the lowest lying absorption bands of these compounds have the transition configurations of HOMO → LUMO, resulting in the transition character of π→π*/n→π*. The transition of HOMO → LUMO+3 mainly contributes to the highest lying absorption bands of two compounds at 225 nm with the character of π→π*/n→π*.展开更多
The reduced graphene oxide/silver selenide nanowire(rGO/Ag;Se NW)composite powders were fabricated via a wet chemical approach,and then flexible rGO/Ag;Se NW composite film was prepared by a facile vacuum filtration m...The reduced graphene oxide/silver selenide nanowire(rGO/Ag;Se NW)composite powders were fabricated via a wet chemical approach,and then flexible rGO/Ag;Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment.A highest power factor of 228.88μW·m;·K;was obtained at 331 K for the cold-pressed rGO/Ag;Se NW composite film with 0.01 wt%r GO.The rGO/Ag;Se NW composite film revealed superior flexibility as the power factor retained 94.62%after bending for 500 times with a bending radius of 4 mm,which might be due to the interwoven network structures of Ag;Se NWs and pliability of r GO as well as nylon membrane.These results demonstrated that the GO/Ag;Se NW composite film has a potential for preparation of flexible thermoelectric devices.展开更多
Deciphering the relationship between polyphase tectonic foliations and their associated mineral assemblages is significant in understanding the process from diagenesis to low-/medium-/high-grade metamorphism.It can pr...Deciphering the relationship between polyphase tectonic foliations and their associated mineral assemblages is significant in understanding the process from diagenesis to low-/medium-/high-grade metamorphism.It can provide information related to strain,metamorphic conditions and overprinting relationships and so help reveal the tectonic evolution of orogenesis.In this study,we predominately focus on the formation of foliations and their related minerals,as developed in two separate basins.First of all,two stages of axial plane cleavages(S1 and S2)were recognized in the Hongyanjing inter-arc basin,the formation of the S1 axial plane cleavage is associated with mica rotation and elongation in mudstones in the local area.The pencil structure of S2 formed during the refolding phase,the minerals in the sedimentary rocks not changing their shape and orientation.Secondly,in the Liao-Ji backarc basin,foliations include diagenetic foliation(bedding parallel foliation),tectonic S1 foliation(secondary foliation or axial plane cleavage of S0 folding)and crenulation cleavage(S2).The formation mechanism of foliation changes from mineral rotation or elongation and mineral solution transfer in S1 to crystal-plastic deformation,dynamic recrystallization and micro-folding in S2.Many index metamorphic minerals formed from low-grade to medium-grade consist of biotites,garnets,staurolite and kyanite,constituting a typical Barrovian metamorphic belt.Accordingly,a new classification of foliation is presented in this study.The foliations can be divided into continuous and disjunctive foliations,based on the existence of microlithons,detectable with the aid of a microscope.Disjunctive foliation can be further sub-divided into spaced foliation and crenulation cleavage,according to whether(or not)crenulation(micro-folding)is present.The size of the mineral grains is also significant for classification of the foliations.展开更多
In this paper,a fully bio-based vinyl oligomer with high functionalities was successfully prepared from rapeseed oil by three modification steps:epoxidation of rapeseed oil,solvent-free and catalyst-free ring opening ...In this paper,a fully bio-based vinyl oligomer with high functionalities was successfully prepared from rapeseed oil by three modification steps:epoxidation of rapeseed oil,solvent-free and catalyst-free ring opening by 10-undecylenic acid followed by esterification with 10-undecenoyl chloride.Then,the renewable polymers were prepared by photo-polymerization of these modified vegetable oils with typical thiol monomers:pentaerythritol tetrakis(3-mercaptopropionate),pentaerythritol tris(3-mercaptopropionate)and 1,2-ethanedithiol.The synthesis of the vinyl oligomer was monitored by nuclear magnetic resonance and Fourier-transform infrared spectroscopy.The average number of the carbon-carbon double bonds of the resulting vinyl oligomer is high to be 7.2.The kinetic of thiol-ene photo-polymerization of vegetable oil-based vinyl oligomer was studied by FTIR-ATR analyses.In addition,the thermo-physical properties,thermal stability and solvent resistance of these UV cured films were characterized.The polymers from 1,2-ethanedithiol exhibit higher gel content,storage modulus and glass transition temperature than those from other thiol monomers due to the high crosslinking densities of the resulting polymers.All polymers show excellent thermal stability up to 290oC.The resulting polymers exhibit thermo-physical properties,excellent water resistance and thermals stability,which is promising to find application in coatings and adhesives.展开更多
OBJECTIVE Erzhi pills is a clas⁃sic prescription of Chinese medicine originated from Fu Shou Jing Fang in Ming dynasty,with the effects of nourishing kidney-Yin and hemosta⁃sis,black hair,strengthening muscles and bon...OBJECTIVE Erzhi pills is a clas⁃sic prescription of Chinese medicine originated from Fu Shou Jing Fang in Ming dynasty,with the effects of nourishing kidney-Yin and hemosta⁃sis,black hair,strengthening muscles and bones.As a classical prescription for nourishing kidney-Yin,Erzhi pills has been used to treat senile dementia in China for many years.Herein,our study aimed to investigate the protective effects of Erzhi pills in rat models of Alzheimer disease(AD)induced by ovariectomy as well as D-galactose and Aβ1-40 injection and to explore its potential mechanism.METHODS The model of AD rats was established by ovariectomy com⁃bined with D-galactose and Aβ1-40 injection.Ovariectomized rats were randomly divided into four groups:model group,estradiol valerate(0.80 mg·kg-1)group,Erzhi pills high(1.50 mg·kg-1)and low(0.75 mg·kg-1)doses group.In addition,rats of sham operation were selected as the sham operated group.Except for the sham oper⁃ated group,rats were injected intraperitoneally with D-galactose(100 mg·kg-1 per day,for 49 d)on the 8th day,then they were given intracerebro⁃ventricular injection of Aβ1-40(10μg per rat,1 g·L-1)on the 36th day,while the corresponding drugs were given by gastrointestinal administra⁃tion on the 22nd day.In our study,Morris water maze test was used to evaluate the learning and memory abilities,while ELISA kit was used to an⁃alyze serum estrogen level.The morphology of hippocampal neuron cells was observed by HE staining,and Nissl staining was utilized to ob⁃serve the Nissl body in cytoplasm.Then,the ex⁃pression of ERβpositive cells and hippocampal Aβ1-40 and p-Tau404 proteins was determined by immunohistochemistry.In order to further explore the molecular mechanism of Erzhi pills preven⁃tion and treatment of AD,proteomics was used to find potential targets and related pathways,Western blotting was used to verify the expres⁃sion of candidate differential protein.According to the results of proteomics in our experiment,Western blotting was used to detect the protein expression of PI3K,Akt,Bcl-2,Bcl-xl,Bad,14-3-3 and GSK3β.RESULTS The escape latency was significantly shortened,the number of crossing platform was increased,the neuron arrange⁃ment was more orderly and with less nuclear pycnosis in rats of Erzhi pills groups compared to the model group.In rats treated with Erzhi pills,the number of neurons,Nissl bodies,the estro⁃gen levels and ERβpositive cells were increased,while the number of Aβ1-40 and p-Tau404 positive cells was significantly decreased.Proteomics found that there were more than one hundred differentially expressed proteins of rats treated with Erzhi pills,which were involved in 48 signal⁃ing pathways.Among these proteins,five of them were involved in the PI3K/Akt signal path⁃way.As the down-stream protein of PI3K/Akt sig⁃naling pathway,the content of 14-3-3 protein was significantly increased.Western blotting analysis showed that the expression of p-GSK3β/GSK3βand Bad was decreased,while that of p-Akt/Akt,p-PI3K/PI3K,14-3-3,Bcl-xl and Bcl-2 was up-regulated in rats from the Erzhi pills groups compared with the model group.CON⁃CLUSION Erzhi pills can improve estrogen levels,alter proteomics expression of the hippocampus and activate PI3K/Akt pathway in AD rats,reduce Aβaggregation,inhibit the hyperphos⁃phorylation of Tau protein,maintain the morphol⁃ogy of hippocampal neurons and decrease the apoptosis of hippocampal neurons,thereby improving the learning and memory abilities of ovariectomized AD rats induced by D-galactose and Aβ1-40 injection.This study may provide an experimental basis for the clinical treatment of Erzhi pills.展开更多
Objective:To explore the molecular mechanism of Zixinyin oral liquid(ZOL)in the treatment of insomnia.Methods:The compounds and action targets of four herbal medicines in ZOL were collected via Traditional Chinese Med...Objective:To explore the molecular mechanism of Zixinyin oral liquid(ZOL)in the treatment of insomnia.Methods:The compounds and action targets of four herbal medicines in ZOL were collected via Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform.Genes corresponding to the targets were queried from the UniProt database.Genecards database was searched to screen the related targets of insomnia.A Gene Ontologyfunction enrichment analysis and a Kyoto Encyclopedia of Genes and Genomespathway enrichment analysis were performed by Database for Annotation,Visualization and Integrated Discovery.AutoDock software was used for molecular docking to verify the results of network analysis.Results:A total of 47 effective compounds and 187 potential targets of ZOL were screened out from the four drugs.A total of 2592 disease targets were screened out from the genecards database,and there were 1576 genes whose relevance score≥0.5.46 genes were obtained by taking the intersection of 187 potential targets of ZOL and 1,576 targets of insomnia.A total of 3,405 entries were obtained from Gene Ontologyfunctional enrichment(P<0.05).A total of 195 signaling pathways were obtained through a Kyoto Encyclopedia of Genes and Genomespathway analysis(P<0.05).Tumor necrosis factor,interleukin 17and hypoxia inducible factor-1signaling pathways were closely related to insomnia.The results of molecular docking show that all the core compounds of ZOL had a certain degree of affinity with gamma-aminobutyric acid receptor subunit alpha-1(GABRA1)and tumor necrosis factor-α(TNF-α).Paeoniflorgenone shows the highest affinity with GABRA1,and beta-sitosterol shows the highest affinity withTNF-α.ZOLmay have a therapeutic effect on insomnia through its action on targets such as GABRA1 and TNF-α,meanwhile regulating many signaling pathways.展开更多
Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single el...Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single electron oxidation reactions for synthesizing structurally diverse functionalized indoles and indolines. Electrocatalysis is considered as a synthetically attractive and environmentally friendly alternative for driving the single electron oxidation of indoles. Remarkable achievements in electrocatalytic indolederived radical cation-mediated indole functionalization have been realized so far. This review comprehensively summarizes the recent progresses in the applications of electrocatalytic indole radical cations,including C(sp~2)–H functionalization, dearomative 2,3-difunctionalization, and ring-opening reaction, emphasizing the vital single electron oxidation steps of indoles, the substrates scope and limitations, and the reaction mechanisms.展开更多
A new,four component copper(Ⅰ)-catalyzed interrupted click/radical relay cascade has been developed.This unprecedented interrupted click reaction provides a rapid modular synthesis of triazole sulfones,important priv...A new,four component copper(Ⅰ)-catalyzed interrupted click/radical relay cascade has been developed.This unprecedented interrupted click reaction provides a rapid modular synthesis of triazole sulfones,important privileged heterocyclic pharmacophores which cannot be accessed by a traditional click reaction.Radical interception of cuprate-triazole,the key reaction intermediate formed in situ,is an important feature of this process.展开更多
Objective:To analyze the necessity of community health service(CHS)development in Jiangxi province based on the current status of healthcare in Jiangxi Province.Method:The study did a systematic survey on the CHS deve...Objective:To analyze the necessity of community health service(CHS)development in Jiangxi province based on the current status of healthcare in Jiangxi Province.Method:The study did a systematic survey on the CHS development among health service organizations in Jiangxi province.The data of the survey were analyzed with system archetype analysis of Peter Senge.Results:Through system analysis,four limits-to-growth archetypes were built and analyzed.The obstacles restricting the development of healthcare systems were determined,and some effective countermeasures were proposed accordingly.Conclusion:In order to foster the sustainable development of healthcare in Jiangxi province and alleviate the problem of“difficulty and high cost to access medical services”effectively,the government should place more emphasis on the development of CHS.展开更多
Objective:Cymbopogon citratus(DC.)Stapf is a medicinal and edible herb that is widely used for the treatment of gastric,nervous and hypertensive disorders.In this study,we investigated the cardioprotective effects and...Objective:Cymbopogon citratus(DC.)Stapf is a medicinal and edible herb that is widely used for the treatment of gastric,nervous and hypertensive disorders.In this study,we investigated the cardioprotective effects and mechanisms of the essential oil,the main active ingredient of Cymbopogon citratus,on isoproterenol(ISO)-induced cardiomyocyte hypertrophy.Methods:The compositions of Cymbopogon citratus essential oil(CCEO)were determined by gas chromatography-mass spectrometry.Cardiomyocytes were pretreated with 16.9µg/L CCEO for 1 h followed by 10µmol/L ISO for 24 h.Cardiac hypertrophy-related indicators and NLRP3 inflammasome expression were evaluated.Subsequently,transcriptome sequencing(RNA-seq)and target verification were used to further explore the underlying mechanism.Results:Our results showed that the CCEO mainly included citronellal(45.66%),geraniol(23.32%),and citronellol(10.37%).CCEO inhibited ISO-induced increases in cell surface area and protein content,as well as the upregulation of fetal gene expression.Moreover,CCEO inhibited ISO-induced NLRP3 inflammasome expression,as evidenced by decreased lactate dehydrogenase content and downregulated mRNA levels of NLRP3,ASC,CASP1,GSDMD,and IL-1β,as well as reduced protein levels of NLRP3,ASC,pro-caspase-1,caspase-1(p20),GSDMD-FL,GSDMD-N,and pro-IL-1β.The RNA-seq results showed that CCEO inhibited the increase in the mRNA levels of 26 oxidative phosphorylation complex subunits in ISO-treated cardiomyocytes.Our further experiments confirmed that CCEO suppressed ISO-induced upregulation of mt-Nd1,Sdhd,mt-Cytb,Uqcrq,and mt-Atp6 but had no obvious effects on mt-Col expression.Conclusion:CCEO inhibits ISO-induced cardiomyocyte hypertrophy through the suppression of NLRP3 inflammasome expression and the regulation of several oxidative phosphorylation complex subunits.展开更多
Aluminum nitride(AlN)is considered one of the most desirable materials for integrated circuits and electronic packaging substrates.However,raw AlN powder reacts easily with water,forming Al(OH)3 or AlOOH on the surfac...Aluminum nitride(AlN)is considered one of the most desirable materials for integrated circuits and electronic packaging substrates.However,raw AlN powder reacts easily with water,forming Al(OH)3 or AlOOH on the surface and hindering the development of an aqueous tape-casting process for preparing AlN ceramic substrates.In this study,hydrolyzed polymaleic anhydride(HPMA)was used to modify AlN powder,which has good water solubility and dispersibility.The AlN powder was modified with 5 wt%HPMA remained stable in water for at least 90 h under magnetic stirring condition and 24 h under ball milling condition,indicating that HPMA-modified AlN powder has good resistance to hydrolysis.The action mechanism of HPMA is revealed.Firstly,–COOH of the HPMA polymer and the oxide layer on the surface of the AlN powder underwent a dehydration condensation reaction to form a compound.Secondly,long chains of the polymer further coated the surface of the AlN powder,forming an anti-hydration layer with a thickness of about 7.0 nm on the surface of the AlN particles.In addition,AlN green sheets were successfully prepared by aqueous tape casting using the HPMA-modified AlN powder without additional dispersants.Subsequently,AlN ceramic substrates were obtained by sintering at 1750℃for 4 h under an N2 atmosphere with a pressure of 0.2 MPa.The relative density and thermal conductivity were tested to be 97.3%and 122 W/(m·K),respectively.展开更多
The design and development of highly permeable,selective and stable polymer membranes are great challenges in the gas separation industry.Herein,we constructed two intrinsic microporous polyimides(6FPCA and 6FMCA)deri...The design and development of highly permeable,selective and stable polymer membranes are great challenges in the gas separation industry.Herein,we constructed two intrinsic microporous polyimides(6FPCA and 6FMCA)derived from two isometric diamines(PCA and MCA),which were synthesized by palladium catalyzed C—N coupling reaction.The PCA and MCA diamines contain a hollow beaded structure of 2,2′-paracyclophane as a building block with a specified window size of 3.09Å.The chemical structures of monomers,polyimides were confirmed by NMR,FTIR,and elementary analysis.6FPCA and 6FMCA exhibit good solubility,excellent thermal stability,and mechanical properties.6FPCA exhibits much larger microporosity(434 versus 120 m2·g−1),FFV(0.22 versus 0.15),d-spacing(6.9 versus 5.9Å),and over 10 times higher permeability with a very little decrease in selectivity than the corresponding polyimide(6FpA)with a plane structure,which remarkably increased their separation performance from far below the 2008 Robeson Upper bounds to reach these limitations for O2/N2 and CO2/CH4.Additionally,the 6FPCA also demonstrates good plasticization resistance,moderate aging properties,and high CO2/CH4 mixed-gas separation performance.These results indicate that paracyclophane subunit can be successfully incorporated into polymers to enhance their ultra-microporosity and separation properties,which open a new avenue for developing high performance gas separation membranes with topological ultra-micropores.展开更多
A naturally occurring nucleoside disulfide,9-(5'-deoxy-5'-thio-β-D-xylofuranosyl)adenine disulfide,was first synthesized from D-xylose over 7 steps in 20%overall yield.The key step involved Vorbriiggen glycos...A naturally occurring nucleoside disulfide,9-(5'-deoxy-5'-thio-β-D-xylofuranosyl)adenine disulfide,was first synthesized from D-xylose over 7 steps in 20%overall yield.The key step involved Vorbriiggen glycosylation of silylated N^6-benzoyladenine with xylose diacetate moiety.展开更多
Objective:This study aims to achieve an empirical evaluation on the functional performances of urban community health care services in fi ve administrative districts of Nanchang city in China.Methods:In order to incre...Objective:This study aims to achieve an empirical evaluation on the functional performances of urban community health care services in fi ve administrative districts of Nanchang city in China.Methods:In order to increase effectiveness,data collected from fi ve administrative districts of Nanchang city were processed to exclude redundant information.Rough set reduction theory was brought in to evaluate the performances of community health care services in these districts through calculating key indices’weighed importance.Results:Comprehensive evaluation showed the score rankings from high to low as Qing-yunpu district,Xihu district,Qingshanhu district,Donghu district,and Wanli district.Conclusion:The objective performance evaluation had actually reflected the general situation(including social-economic status)of community health care services in these administrative districts of Nanchang.Attention and practical works of community health service management were needed to build a more harmonious and uniform community health care service system for residents in these districts of Nanchang.展开更多
In this work,we designed and synthesized a novel naphthalenediimide-based n-type conjugated polymer PNDICI,which bears asymmetric backbone containing a 3-chlorothiophene unit.The asymmetric structure associated with s...In this work,we designed and synthesized a novel naphthalenediimide-based n-type conjugated polymer PNDICI,which bears asymmetric backbone containing a 3-chlorothiophene unit.The asymmetric structure associated with steric effects of the chlorine atom imparts remarkable solubility to PNDICI in various organic solvents,enabling the fabrication of all-polymer solar cells(all-PSCs)by using an environmentally friendly solvent of d-limonene.Combined with a novel pyrrolo[3,4-f]benzotriazole-5,7(6H)-dione based p-type conjugated polymer P2F-Si with deep highest occupied molecular orbital energy level,the resulting d-limonene-processed all-PSCs presents an impressively high open-circuit voltage of approaching 1.0 V,corresponding to a very small energy loss of 0.49 eV.Through further morphology optimization by usingγ-valerolactone,we demonstrated an impressive device efficiency of 4.2%,which is among the best photovoltaic performance of devices processed using d-limonene and comparable to that processed by conventional solvent,suggesting the great promise of using greener solvent for fabricating high-performance all-PSCs.展开更多
Photocatalysts with exposure of different crystal facets often show great differences in their photocatalytic activities due to differences in surface atomic arrangement and coordination.Thus,the actual photoreaction ...Photocatalysts with exposure of different crystal facets often show great differences in their photocatalytic activities due to differences in surface atomic arrangement and coordination.Thus,the actual photoreaction mechanism of a specific crystal facet in photocatalysis deserves to be explored.In this paper,as a case study,Sr Bi_(2)Ta_(2)O_(9)photocatalyst with preferential facet exposure was explored for the photocatalytic removal of NO at a ppb level.The efficiency of NO removal was remarkably improved by tuning the crystal exposure facet with high(200)facet exposure ratio.Optimized exposure of(200)crystal facet in Sr Bi_(2)Ta_(2)O_(9)(SBT)by thermal calcination at 800℃(SBT-800)leads to the highest NO removal activity of51%under a 300 W Xe lamp for 20 min;under visible light,SBT 800 achieves a 5-fold enhancement in NO removal efficiency compared to its counterpart,SBT-900.Active species capture experiments prove that the superoxide radical·O_(2)-is the main active species for the photocatalytic removal of NO,and surface selective deposition experiments conclude that(200)is the main electron-rich crystal plane,based on which the results of density functional theory(DFT)computation reveal the Bi O terminated nature of(001)crystal plane,where the models with both Bi O and Ta O terminated(001)planes were created and computated.Mechanistic study reveals that Sr Bi_(2)Ta_(2)O_(9)with a larger exposure of(200)facet provides more active reduction sites,thereby reducing more O_(2)to·O_(2)-,which further oxidizes the adsorbed NO to NO_(2)-/NO_(3)-.The present work underlines the role of facet tuning in the photoactivity modulation for NO removal photocatalytically.展开更多
The Ni(II)-catalyzed intermolecular arylation of unactivated alkenes with arylboronic acids has been disclosed for the first time.This alkene arylation exhibits excellent E/Z selectivity and regioselectivity(γ-select...The Ni(II)-catalyzed intermolecular arylation of unactivated alkenes with arylboronic acids has been disclosed for the first time.This alkene arylation exhibits excellent E/Z selectivity and regioselectivity(γ-selectivity)to provide the correspondingγ-aryl substitutedβ,γ-unsaturated carboxylic acid derivatives with E-selectivity.A Heck-type mechanism is proposed,wherein the 8-aminoquinoline auxiliary group takes the crucial role of the alkenes in the insertion/β-H elimination steps.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11104319,11274346,51202285,61234005,51172268,51602340,61274059,and 51402347)the Solar Energy Action Plan of Chinese Academy of Sciences(Grant Nos.Y1YT064001,Y1YF034001,and Y2YF014001)+2 种基金the Graduate and College Student’s Innovative Project(Grant No.YC2016-X19)the Project of Beijing Municipal Science and Technology Commission(Grant No.Z151100003515003)the Opening Project of Key Laboratory of Microelectronics Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences
文摘Interdigitated back contact(IBC) solar cells can achieve a very high efficiency due to its less optical losses. But IBC solar cells demand for high quality passivation of the front surface. In this paper, a polycrystalline silicon/SiO_2 stack structure as front surface field to passivate the front surface of IBC solar cells is proposed. The passivation quality of this structure is investigated by two dimensional simulations. Polycrystalline silicon layer and SiO_2 layer are optimized to get the best passivation quality of the IBC solar cell. Simulation results indicate that the doping level of polycrystalline silicon should be high enough to allow a very thin polycrystalline silicon layer to ensure an effective passivation and small optical losses at the same time. The thickness of SiO_2 should be neither too thin nor too thick, and the optimal thickness is 1.2 nm.Furthermore, the lateral transport properties of electrons are investigated, and the simulation results indicate that a high doping level and conductivity of polycrystalline silicon can improve the lateral transportation of electrons and then the cell performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.51762018,52073128,and 22065013)the Natural Science Foundation of Jiangxi Province,China(Grant Nos.20202ACBL204005,20202ACBL214005,and 20203AEI003)。
文摘Poly(3,4-ethylenedioxythiophene)(PEDOT)has proved its quite competitive thermoelectric properties in flexible electronics with its excellent electrical and mechanical properties.Since the early discovery of PEDOT,considerable experimental progress has been achieved in optimizing and improving the thermoelectric properties as a promising organic thermoelectric material(OTE).Among them,theoretical research has made significant contributions to its development.Here the basic physics of conductive PEDOT are reviewed based on the combination of theory and experiment.The purpose is to provide a new insight into the development of PEDOT,so as to effectively design and preparation of advanced thermoelectric PEDOT material in the future.
基金supported by the National Natural Science Foundation of China (No.20903049)the Science and Technology Foundation of Jiangxi Provincial Education Department of China (No.GJJ12588)
文摘The ground state geometries, frontier molecular orbital properties, and absorption properties of 4,4′-(ethane-1,2-diylbis(oxy))dibenzaldehyde (EDO-DBDHD) and its polymorph have been studied theoretically. The density functional theory (DFT) method was employed to optimize the ground state geometries, and theoretical data reveal that EDO-DBDHD features the planar molecular conformations, in contrast to V-shaped structures of its polymorph, which agrees with the experimental data. Additionally, the absorption spectra of both compounds were predicted using time-dependent density functional theory (TDDFT). The calculated results show that the lowest lying absorption bands of these compounds have the transition configurations of HOMO → LUMO, resulting in the transition character of π→π*/n→π*. The transition of HOMO → LUMO+3 mainly contributes to the highest lying absorption bands of two compounds at 225 nm with the character of π→π*/n→π*.
基金supported by the Program for Professor of Special Appointment at Shanghai Institutions of Higher Learning(Grant No.TP2020068)Shanghai Innovation Action Plan Project(Grant No.17090503600)Shanghai Sailing Program(Grant No.20YF1447300)。
文摘The reduced graphene oxide/silver selenide nanowire(rGO/Ag;Se NW)composite powders were fabricated via a wet chemical approach,and then flexible rGO/Ag;Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment.A highest power factor of 228.88μW·m;·K;was obtained at 331 K for the cold-pressed rGO/Ag;Se NW composite film with 0.01 wt%r GO.The rGO/Ag;Se NW composite film revealed superior flexibility as the power factor retained 94.62%after bending for 500 times with a bending radius of 4 mm,which might be due to the interwoven network structures of Ag;Se NWs and pliability of r GO as well as nylon membrane.These results demonstrated that the GO/Ag;Se NW composite film has a potential for preparation of flexible thermoelectric devices.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.92062214,41430210 and 41888101)the NSFC Regional Science Foundation(Grant No.41962012)+3 种基金the Scientific Program of Jiangxi Educational Committee(Grant No.GJJ190586)the Chinese Geological Survey projects(Grant No.DD20190003)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(CAS)(Grant No.XDB18020203)the Basic Scientific Research Foundations of the Institute of Geology,Chinese Academy of Geological Sciences(Grant No.J2030,J2009)。
文摘Deciphering the relationship between polyphase tectonic foliations and their associated mineral assemblages is significant in understanding the process from diagenesis to low-/medium-/high-grade metamorphism.It can provide information related to strain,metamorphic conditions and overprinting relationships and so help reveal the tectonic evolution of orogenesis.In this study,we predominately focus on the formation of foliations and their related minerals,as developed in two separate basins.First of all,two stages of axial plane cleavages(S1 and S2)were recognized in the Hongyanjing inter-arc basin,the formation of the S1 axial plane cleavage is associated with mica rotation and elongation in mudstones in the local area.The pencil structure of S2 formed during the refolding phase,the minerals in the sedimentary rocks not changing their shape and orientation.Secondly,in the Liao-Ji backarc basin,foliations include diagenetic foliation(bedding parallel foliation),tectonic S1 foliation(secondary foliation or axial plane cleavage of S0 folding)and crenulation cleavage(S2).The formation mechanism of foliation changes from mineral rotation or elongation and mineral solution transfer in S1 to crystal-plastic deformation,dynamic recrystallization and micro-folding in S2.Many index metamorphic minerals formed from low-grade to medium-grade consist of biotites,garnets,staurolite and kyanite,constituting a typical Barrovian metamorphic belt.Accordingly,a new classification of foliation is presented in this study.The foliations can be divided into continuous and disjunctive foliations,based on the existence of microlithons,detectable with the aid of a microscope.Disjunctive foliation can be further sub-divided into spaced foliation and crenulation cleavage,according to whether(or not)crenulation(micro-folding)is present.The size of the mineral grains is also significant for classification of the foliations.
基金sponsored by the National Natural Science Foundation of China(51563011)the Natural Science Foundation of Jiangxi Province(2016BAB203094)+1 种基金the Young Talents Project of Jiangxi Science and Technology Normal University(2016QNBJRC007)the Postgraduate Innovation Fund Project of Jiangxi Science and Technology Normal University(YC2019-X31).
文摘In this paper,a fully bio-based vinyl oligomer with high functionalities was successfully prepared from rapeseed oil by three modification steps:epoxidation of rapeseed oil,solvent-free and catalyst-free ring opening by 10-undecylenic acid followed by esterification with 10-undecenoyl chloride.Then,the renewable polymers were prepared by photo-polymerization of these modified vegetable oils with typical thiol monomers:pentaerythritol tetrakis(3-mercaptopropionate),pentaerythritol tris(3-mercaptopropionate)and 1,2-ethanedithiol.The synthesis of the vinyl oligomer was monitored by nuclear magnetic resonance and Fourier-transform infrared spectroscopy.The average number of the carbon-carbon double bonds of the resulting vinyl oligomer is high to be 7.2.The kinetic of thiol-ene photo-polymerization of vegetable oil-based vinyl oligomer was studied by FTIR-ATR analyses.In addition,the thermo-physical properties,thermal stability and solvent resistance of these UV cured films were characterized.The polymers from 1,2-ethanedithiol exhibit higher gel content,storage modulus and glass transition temperature than those from other thiol monomers due to the high crosslinking densities of the resulting polymers.All polymers show excellent thermal stability up to 290oC.The resulting polymers exhibit thermo-physical properties,excellent water resistance and thermals stability,which is promising to find application in coatings and adhesives.
文摘OBJECTIVE Erzhi pills is a clas⁃sic prescription of Chinese medicine originated from Fu Shou Jing Fang in Ming dynasty,with the effects of nourishing kidney-Yin and hemosta⁃sis,black hair,strengthening muscles and bones.As a classical prescription for nourishing kidney-Yin,Erzhi pills has been used to treat senile dementia in China for many years.Herein,our study aimed to investigate the protective effects of Erzhi pills in rat models of Alzheimer disease(AD)induced by ovariectomy as well as D-galactose and Aβ1-40 injection and to explore its potential mechanism.METHODS The model of AD rats was established by ovariectomy com⁃bined with D-galactose and Aβ1-40 injection.Ovariectomized rats were randomly divided into four groups:model group,estradiol valerate(0.80 mg·kg-1)group,Erzhi pills high(1.50 mg·kg-1)and low(0.75 mg·kg-1)doses group.In addition,rats of sham operation were selected as the sham operated group.Except for the sham oper⁃ated group,rats were injected intraperitoneally with D-galactose(100 mg·kg-1 per day,for 49 d)on the 8th day,then they were given intracerebro⁃ventricular injection of Aβ1-40(10μg per rat,1 g·L-1)on the 36th day,while the corresponding drugs were given by gastrointestinal administra⁃tion on the 22nd day.In our study,Morris water maze test was used to evaluate the learning and memory abilities,while ELISA kit was used to an⁃alyze serum estrogen level.The morphology of hippocampal neuron cells was observed by HE staining,and Nissl staining was utilized to ob⁃serve the Nissl body in cytoplasm.Then,the ex⁃pression of ERβpositive cells and hippocampal Aβ1-40 and p-Tau404 proteins was determined by immunohistochemistry.In order to further explore the molecular mechanism of Erzhi pills preven⁃tion and treatment of AD,proteomics was used to find potential targets and related pathways,Western blotting was used to verify the expres⁃sion of candidate differential protein.According to the results of proteomics in our experiment,Western blotting was used to detect the protein expression of PI3K,Akt,Bcl-2,Bcl-xl,Bad,14-3-3 and GSK3β.RESULTS The escape latency was significantly shortened,the number of crossing platform was increased,the neuron arrange⁃ment was more orderly and with less nuclear pycnosis in rats of Erzhi pills groups compared to the model group.In rats treated with Erzhi pills,the number of neurons,Nissl bodies,the estro⁃gen levels and ERβpositive cells were increased,while the number of Aβ1-40 and p-Tau404 positive cells was significantly decreased.Proteomics found that there were more than one hundred differentially expressed proteins of rats treated with Erzhi pills,which were involved in 48 signal⁃ing pathways.Among these proteins,five of them were involved in the PI3K/Akt signal path⁃way.As the down-stream protein of PI3K/Akt sig⁃naling pathway,the content of 14-3-3 protein was significantly increased.Western blotting analysis showed that the expression of p-GSK3β/GSK3βand Bad was decreased,while that of p-Akt/Akt,p-PI3K/PI3K,14-3-3,Bcl-xl and Bcl-2 was up-regulated in rats from the Erzhi pills groups compared with the model group.CON⁃CLUSION Erzhi pills can improve estrogen levels,alter proteomics expression of the hippocampus and activate PI3K/Akt pathway in AD rats,reduce Aβaggregation,inhibit the hyperphos⁃phorylation of Tau protein,maintain the morphol⁃ogy of hippocampal neurons and decrease the apoptosis of hippocampal neurons,thereby improving the learning and memory abilities of ovariectomized AD rats induced by D-galactose and Aβ1-40 injection.This study may provide an experimental basis for the clinical treatment of Erzhi pills.
基金This work was supported by the Hubei Science and Technology Program(No.2020CFB231)Youth Talent Project of Health Commission of Hubei Province(No.ZY2021Q026)Hubei University of Science and Technology Doctoral Startup Fund Project(No.BK202029).
文摘Objective:To explore the molecular mechanism of Zixinyin oral liquid(ZOL)in the treatment of insomnia.Methods:The compounds and action targets of four herbal medicines in ZOL were collected via Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform.Genes corresponding to the targets were queried from the UniProt database.Genecards database was searched to screen the related targets of insomnia.A Gene Ontologyfunction enrichment analysis and a Kyoto Encyclopedia of Genes and Genomespathway enrichment analysis were performed by Database for Annotation,Visualization and Integrated Discovery.AutoDock software was used for molecular docking to verify the results of network analysis.Results:A total of 47 effective compounds and 187 potential targets of ZOL were screened out from the four drugs.A total of 2592 disease targets were screened out from the genecards database,and there were 1576 genes whose relevance score≥0.5.46 genes were obtained by taking the intersection of 187 potential targets of ZOL and 1,576 targets of insomnia.A total of 3,405 entries were obtained from Gene Ontologyfunctional enrichment(P<0.05).A total of 195 signaling pathways were obtained through a Kyoto Encyclopedia of Genes and Genomespathway analysis(P<0.05).Tumor necrosis factor,interleukin 17and hypoxia inducible factor-1signaling pathways were closely related to insomnia.The results of molecular docking show that all the core compounds of ZOL had a certain degree of affinity with gamma-aminobutyric acid receptor subunit alpha-1(GABRA1)and tumor necrosis factor-α(TNF-α).Paeoniflorgenone shows the highest affinity with GABRA1,and beta-sitosterol shows the highest affinity withTNF-α.ZOLmay have a therapeutic effect on insomnia through its action on targets such as GABRA1 and TNF-α,meanwhile regulating many signaling pathways.
基金the National Natural Science Foundation of China (No.22261019)the Jiangxi Provincial Natural Science Foundation (No.20224BAB213004)+1 种基金the Education Department of Jiangxi Province(Nos.GJJ211134 and GJJ211137)the PhD start-up fund of Jiangxi Science&Technology Normal University (No.2021BSQD32) for financial support。
文摘Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single electron oxidation reactions for synthesizing structurally diverse functionalized indoles and indolines. Electrocatalysis is considered as a synthetically attractive and environmentally friendly alternative for driving the single electron oxidation of indoles. Remarkable achievements in electrocatalytic indolederived radical cation-mediated indole functionalization have been realized so far. This review comprehensively summarizes the recent progresses in the applications of electrocatalytic indole radical cations,including C(sp~2)–H functionalization, dearomative 2,3-difunctionalization, and ring-opening reaction, emphasizing the vital single electron oxidation steps of indoles, the substrates scope and limitations, and the reaction mechanisms.
基金financial support from the Natural Science Foundation of China and Shandong Province(Nos.21971149,92156007,ZR2019ZD45,ZR2020KB005)the Fundamental Research Funds of Shandong University。
文摘A new,four component copper(Ⅰ)-catalyzed interrupted click/radical relay cascade has been developed.This unprecedented interrupted click reaction provides a rapid modular synthesis of triazole sulfones,important privileged heterocyclic pharmacophores which cannot be accessed by a traditional click reaction.Radical interception of cuprate-triazole,the key reaction intermediate formed in situ,is an important feature of this process.
基金Supported by National Natural Science Foundation of China(Grant NO.71163016)Science and Technology Planning Project of Jiangxi Educational Committee(GJJ 13559)。
文摘Objective:To analyze the necessity of community health service(CHS)development in Jiangxi province based on the current status of healthcare in Jiangxi Province.Method:The study did a systematic survey on the CHS development among health service organizations in Jiangxi province.The data of the survey were analyzed with system archetype analysis of Peter Senge.Results:Through system analysis,four limits-to-growth archetypes were built and analyzed.The obstacles restricting the development of healthcare systems were determined,and some effective countermeasures were proposed accordingly.Conclusion:In order to foster the sustainable development of healthcare in Jiangxi province and alleviate the problem of“difficulty and high cost to access medical services”effectively,the government should place more emphasis on the development of CHS.
基金supported by grants from the National Natural Science Foundation of China(Nos.81960732 and 82060733)the Natural Science Foundation of Jiangxi Province(No.20224BAB206111)+2 种基金the Science and Technology Plan of Jiangxi Provincial Health Commission(No.202311141)the Open Project of Jiangxi Provincial Key Laboratory of Drug Design and Evaluation(No.JKLDE-KF-2101)the Open Project of Key Laboratory of Modern Preparation of TCM,Ministry of Education,Jiangxi University of Chinese Medicine(No.TCM-201911).
文摘Objective:Cymbopogon citratus(DC.)Stapf is a medicinal and edible herb that is widely used for the treatment of gastric,nervous and hypertensive disorders.In this study,we investigated the cardioprotective effects and mechanisms of the essential oil,the main active ingredient of Cymbopogon citratus,on isoproterenol(ISO)-induced cardiomyocyte hypertrophy.Methods:The compositions of Cymbopogon citratus essential oil(CCEO)were determined by gas chromatography-mass spectrometry.Cardiomyocytes were pretreated with 16.9µg/L CCEO for 1 h followed by 10µmol/L ISO for 24 h.Cardiac hypertrophy-related indicators and NLRP3 inflammasome expression were evaluated.Subsequently,transcriptome sequencing(RNA-seq)and target verification were used to further explore the underlying mechanism.Results:Our results showed that the CCEO mainly included citronellal(45.66%),geraniol(23.32%),and citronellol(10.37%).CCEO inhibited ISO-induced increases in cell surface area and protein content,as well as the upregulation of fetal gene expression.Moreover,CCEO inhibited ISO-induced NLRP3 inflammasome expression,as evidenced by decreased lactate dehydrogenase content and downregulated mRNA levels of NLRP3,ASC,CASP1,GSDMD,and IL-1β,as well as reduced protein levels of NLRP3,ASC,pro-caspase-1,caspase-1(p20),GSDMD-FL,GSDMD-N,and pro-IL-1β.The RNA-seq results showed that CCEO inhibited the increase in the mRNA levels of 26 oxidative phosphorylation complex subunits in ISO-treated cardiomyocytes.Our further experiments confirmed that CCEO suppressed ISO-induced upregulation of mt-Nd1,Sdhd,mt-Cytb,Uqcrq,and mt-Atp6 but had no obvious effects on mt-Col expression.Conclusion:CCEO inhibits ISO-induced cardiomyocyte hypertrophy through the suppression of NLRP3 inflammasome expression and the regulation of several oxidative phosphorylation complex subunits.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52102101,52267001)the Natural Science Foundation of Jiangxi Province(No.20212BAB204019).
文摘Aluminum nitride(AlN)is considered one of the most desirable materials for integrated circuits and electronic packaging substrates.However,raw AlN powder reacts easily with water,forming Al(OH)3 or AlOOH on the surface and hindering the development of an aqueous tape-casting process for preparing AlN ceramic substrates.In this study,hydrolyzed polymaleic anhydride(HPMA)was used to modify AlN powder,which has good water solubility and dispersibility.The AlN powder was modified with 5 wt%HPMA remained stable in water for at least 90 h under magnetic stirring condition and 24 h under ball milling condition,indicating that HPMA-modified AlN powder has good resistance to hydrolysis.The action mechanism of HPMA is revealed.Firstly,–COOH of the HPMA polymer and the oxide layer on the surface of the AlN powder underwent a dehydration condensation reaction to form a compound.Secondly,long chains of the polymer further coated the surface of the AlN powder,forming an anti-hydration layer with a thickness of about 7.0 nm on the surface of the AlN particles.In addition,AlN green sheets were successfully prepared by aqueous tape casting using the HPMA-modified AlN powder without additional dispersants.Subsequently,AlN ceramic substrates were obtained by sintering at 1750℃for 4 h under an N2 atmosphere with a pressure of 0.2 MPa.The relative density and thermal conductivity were tested to be 97.3%and 122 W/(m·K),respectively.
基金financially supported by the National Natural Science Foundation of China (Nos. 22078245 and 21861016)YLU-DNL Fund (No. 2022009)
文摘The design and development of highly permeable,selective and stable polymer membranes are great challenges in the gas separation industry.Herein,we constructed two intrinsic microporous polyimides(6FPCA and 6FMCA)derived from two isometric diamines(PCA and MCA),which were synthesized by palladium catalyzed C—N coupling reaction.The PCA and MCA diamines contain a hollow beaded structure of 2,2′-paracyclophane as a building block with a specified window size of 3.09Å.The chemical structures of monomers,polyimides were confirmed by NMR,FTIR,and elementary analysis.6FPCA and 6FMCA exhibit good solubility,excellent thermal stability,and mechanical properties.6FPCA exhibits much larger microporosity(434 versus 120 m2·g−1),FFV(0.22 versus 0.15),d-spacing(6.9 versus 5.9Å),and over 10 times higher permeability with a very little decrease in selectivity than the corresponding polyimide(6FpA)with a plane structure,which remarkably increased their separation performance from far below the 2008 Robeson Upper bounds to reach these limitations for O2/N2 and CO2/CH4.Additionally,the 6FPCA also demonstrates good plasticization resistance,moderate aging properties,and high CO2/CH4 mixed-gas separation performance.These results indicate that paracyclophane subunit can be successfully incorporated into polymers to enhance their ultra-microporosity and separation properties,which open a new avenue for developing high performance gas separation membranes with topological ultra-micropores.
基金NSFC(Nos.20962009 and 21062006)NCET(No.11-1000)+1 种基金the Training Project of Jiangxi Youth Scientists,Education Department of Jiangxi Province(No.GJJ 11223)Bureau of Science & Technology of Nanchang City for financial support
文摘A naturally occurring nucleoside disulfide,9-(5'-deoxy-5'-thio-β-D-xylofuranosyl)adenine disulfide,was first synthesized from D-xylose over 7 steps in 20%overall yield.The key step involved Vorbriiggen glycosylation of silylated N^6-benzoyladenine with xylose diacetate moiety.
基金the National Natural Science Foundation of China in 2011[71163016]the Technology Project of Provincial Education Department of Jiangxi in 2013[GJJ13559].
文摘Objective:This study aims to achieve an empirical evaluation on the functional performances of urban community health care services in fi ve administrative districts of Nanchang city in China.Methods:In order to increase effectiveness,data collected from fi ve administrative districts of Nanchang city were processed to exclude redundant information.Rough set reduction theory was brought in to evaluate the performances of community health care services in these districts through calculating key indices’weighed importance.Results:Comprehensive evaluation showed the score rankings from high to low as Qing-yunpu district,Xihu district,Qingshanhu district,Donghu district,and Wanli district.Conclusion:The objective performance evaluation had actually reflected the general situation(including social-economic status)of community health care services in these administrative districts of Nanchang.Attention and practical works of community health service management were needed to build a more harmonious and uniform community health care service system for residents in these districts of Nanchang.
基金Science Foundation of China(Nos.21822505,21905103)Dongguan Science and Technology Bureau(Nos.2018607201002,2019622163009)the Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007).
文摘In this work,we designed and synthesized a novel naphthalenediimide-based n-type conjugated polymer PNDICI,which bears asymmetric backbone containing a 3-chlorothiophene unit.The asymmetric structure associated with steric effects of the chlorine atom imparts remarkable solubility to PNDICI in various organic solvents,enabling the fabrication of all-polymer solar cells(all-PSCs)by using an environmentally friendly solvent of d-limonene.Combined with a novel pyrrolo[3,4-f]benzotriazole-5,7(6H)-dione based p-type conjugated polymer P2F-Si with deep highest occupied molecular orbital energy level,the resulting d-limonene-processed all-PSCs presents an impressively high open-circuit voltage of approaching 1.0 V,corresponding to a very small energy loss of 0.49 eV.Through further morphology optimization by usingγ-valerolactone,we demonstrated an impressive device efficiency of 4.2%,which is among the best photovoltaic performance of devices processed using d-limonene and comparable to that processed by conventional solvent,suggesting the great promise of using greener solvent for fabricating high-performance all-PSCs.
基金supported by the National Natural Science Foundation of China(Nos.21976116,52161145409)Shaanxi Science and Technology Program(No.2020KWZ-005)+3 种基金High Level Talents Introduction Project of"Pearl River Talent Plan"in Guangdong Province(No.2019CX01L308)the Support Scheme of Guangzhou for Leading Talents in Innovation and Entrepreneurship Funding(No.2016015)SAFEA of China(High-end Foreign Expert Project)Alexander-von-Humboldt Foundation of Germany(Group-Linkage Program)。
文摘Photocatalysts with exposure of different crystal facets often show great differences in their photocatalytic activities due to differences in surface atomic arrangement and coordination.Thus,the actual photoreaction mechanism of a specific crystal facet in photocatalysis deserves to be explored.In this paper,as a case study,Sr Bi_(2)Ta_(2)O_(9)photocatalyst with preferential facet exposure was explored for the photocatalytic removal of NO at a ppb level.The efficiency of NO removal was remarkably improved by tuning the crystal exposure facet with high(200)facet exposure ratio.Optimized exposure of(200)crystal facet in Sr Bi_(2)Ta_(2)O_(9)(SBT)by thermal calcination at 800℃(SBT-800)leads to the highest NO removal activity of51%under a 300 W Xe lamp for 20 min;under visible light,SBT 800 achieves a 5-fold enhancement in NO removal efficiency compared to its counterpart,SBT-900.Active species capture experiments prove that the superoxide radical·O_(2)-is the main active species for the photocatalytic removal of NO,and surface selective deposition experiments conclude that(200)is the main electron-rich crystal plane,based on which the results of density functional theory(DFT)computation reveal the Bi O terminated nature of(001)crystal plane,where the models with both Bi O and Ta O terminated(001)planes were created and computated.Mechanistic study reveals that Sr Bi_(2)Ta_(2)O_(9)with a larger exposure of(200)facet provides more active reduction sites,thereby reducing more O_(2)to·O_(2)-,which further oxidizes the adsorbed NO to NO_(2)-/NO_(3)-.The present work underlines the role of facet tuning in the photoactivity modulation for NO removal photocatalytically.
基金Funding from the Natural Science Foundation of China(No.51963010)the Natural Science Foundation of Jiangxi Province(No.20202BABL213005 and No.20212BAB203008)the Science Foundation of the Education Office of Jiangxi Province(No.GJJ201111)is acknowledged.
文摘The Ni(II)-catalyzed intermolecular arylation of unactivated alkenes with arylboronic acids has been disclosed for the first time.This alkene arylation exhibits excellent E/Z selectivity and regioselectivity(γ-selectivity)to provide the correspondingγ-aryl substitutedβ,γ-unsaturated carboxylic acid derivatives with E-selectivity.A Heck-type mechanism is proposed,wherein the 8-aminoquinoline auxiliary group takes the crucial role of the alkenes in the insertion/β-H elimination steps.