Deep insights into electrocatalytic mechanisms are vital for the rational design of catalysts for oxygen evolution reaction(OER).Mechanistically,the OER driven by adsorbate evolution mechanism(AEM)is limited by the li...Deep insights into electrocatalytic mechanisms are vital for the rational design of catalysts for oxygen evolution reaction(OER).Mechanistically,the OER driven by adsorbate evolution mechanism(AEM)is limited by the linear scaling relationship,thereby exhibiting large overpotentials.In the lattice oxygen mechanism(LOM),the OER can be enhanced by enabling direct O_(2)formation.However,this enhancement is accompanied by the generation of oxygen vacancies,which presents a significant challenge to the long-term stability of LOMOER,particularly when operating at high current densities.Recently,the*O-*O coupling mechanism(OCM)has emerged as a promising alternative;it not only breaks the linear scaling relationship but also ensures catalytic stability.This review encapsulates the cutting-edge advancements in electrocatalysts that are grounded in the OCM,offering a detailed interpretation on the foundational principles guiding the design of OCM-OER catalysts.It also highlights recent theoretical investigations combining machine learning(ML)with density functional theory(DFT)calculations to reveal OER mechanisms.At the end of this review,the challenges and opportunities associated with OCM-OER electrocatalysts are discussed.展开更多
Psathyrostachys huashanica Keng ex P.C.Kuo(2n=2x=14,NsNs),a wild relative of wheat,represents a valuable germplasm resource for genetic improvement of wheat.We previously confirmed that a chromosome 7Ns from P.huashan...Psathyrostachys huashanica Keng ex P.C.Kuo(2n=2x=14,NsNs),a wild relative of wheat,represents a valuable germplasm resource for genetic improvement of wheat.We previously confirmed that a chromosome 7Ns from P.huashanica carries genes that accelerate heading and maturity in wheat.Here,we developed three small segment translocation lines(T7NsS-2BL 2BS,T7NsS-1AS 1AL#1,and T7NsS-1AS 1AL#2)along with one additional small segment translocation line(T7NsS-7BS 7BL)through^(60)Co-γ irradiation,identified using genomic in situ hybridization(GISH),fluorescence in situ hybridization(FISH),and liquid chip array analyses.Our findings demonstrated that chromosome 7NsS contained a major early heading date gene,tentatively designated Ehd-7Ns,which was mapped to an approximate31.45 Mb region,corresponding to the short arm of wheat chromosome 7A(IWGSC RefSeq v1.0).The T7NsS-1AS 1AL#2 line exhibited no significant yield penalty and possessed superior agronomic traits relative to the other translocation lines in the field,making it a promising pre-breeding donor for breeding early maturing wheat.Furthermore,21 specific Kompetitive Allele Specific PCR(KASP)markers were developed based on transcriptome data,enabling effective tracing of alien chromosomal segments carrying this source of Ehd-7Ns in marker-assisted breeding.Collectively,these newly developed translocation lines and specific KASP markers will facilitate the transfer and utilization of favorable genes from P.huashanica chromosome 7Ns in future wheat breeding programs.展开更多
Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,...Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,energy,materials,quantum,and microelectronics.Surface science mainly investigates the correspondence between surface property and functionality.Scanning probe microscopy(SPM)techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging,spectroscopy and manipulation at the single-atom level.In this review,we summarize recent advances in surface electronic,magnetic and optical properties characterized mainly by SPM-based methods.We focus on elucidating theπ-magnetism in graphene-based nanostructures,construction of spin qubits on surfaces,topology properties of surface organic structures,STM-based light emission,tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.展开更多
Fusarium head blight(FHB),mainly caused by Fusarium graminearum,is one of the most destructive fungal diseases affecting global wheat production.Elymus repens(2n=6×=42,StStStStHH),a wild relative of wheat,exhibit...Fusarium head blight(FHB),mainly caused by Fusarium graminearum,is one of the most destructive fungal diseases affecting global wheat production.Elymus repens(2n=6×=42,StStStStHH),a wild relative of wheat,exhibits numerous biotic and abiotic stress resistance characteristics.In previous studies,FHB resistance of E.repens has been transferred into common wheat through a wheat-E.repens partial amphidiploid and derivative lines.This study reports the development,characterization,and breeding utilization of K140-7,a novel wheat-E.repens translocation line conferring resistance to FHB.Genomic in situ hybridization(GISH)and fluorescence in situ hybridization(FISH)analyses demonstrated that K140-7 contained 40 common wheat chromosomes and two 7D·St translocation chromosomes.Subsequent characterization using oligonucleotide-FISH painting and single-gene FISH markers confirmed that the 7D fragment was a 7D short arm and the St fragment was a 7St long arm.Therefore,K140-7 was further identified as a 7DS·7StL translocation line with genetic compensation.Wheat 55K SNP array analysis of K140-7 demonstrated the 7DS·7StL translocation event.Field evaluations demonstrated that K140-7 exhibits agronomic performance comparable to its wheat parent.Based on St reference genome of Pseudoroegneria libanotica,21 simple sequence repeats(SSR)markers specific to 7StL were developed.Genetic analysis established that 7StL confers FHB resistance and carries the dominant FHB resistance locus,designated as QFhb.Er-7StL.Introgression of QFhb.Er-7StL into elite wheat cultivars has generated three second-generation 7DS·7StL translocation lines with enhanced agronomic traits.This study provides valuable novel germplasms and specific molecular markers for FHB resistance breeding in wheat.展开更多
Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,a...Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.展开更多
Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated. The catalysts before and after reaction ...Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated. The catalysts before and after reaction were characterized by BET, CO chemisorption, XRD and XPS techniques. Results showed that the presence of Ce significantly increased the activity and thermal stability of the Pd-Pt/Al2O3 catalyst towards methane combustion, which could be attributed to more highly-dispersed active PdO particles over the Pd-Pt/Ce/Al2O3 catalyst surface as well as the retarded sintering of PdO and the maintained oxidized state of surface Pd during the combustion process in the presence of Ce.展开更多
Promoted catalytic reaction between methanol and CO2 for dimethyl carbonate （DMC） synthesis is conducted over K2CO3/CH3I catalyst in the presence of ionic liquid under microwave irradiation. The effect of ionic liqu...Promoted catalytic reaction between methanol and CO2 for dimethyl carbonate （DMC） synthesis is conducted over K2CO3/CH3I catalyst in the presence of ionic liquid under microwave irradiation. The effect of ionic liquids incorporated with microwave irradiation on the yield of DMC is investigated. DMC was found to form at lower temperature in a relative short time, which indicated an enhanced catalytic process by ionic liquid. Among the ionic liquids used, 1-butyl-3-methylimidazolium chloride is the most effective promoter. Density functional theory calculations indicate that CO2 bond lengths and angles changed due to the molecular interaction of ionic liquid and CO2, resulting in the activation of CO2 molecules and consequently the acceleration of reaction rate.展开更多
In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich de...In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich detector is of the semi-well type, so it has a higher detection efficiency. The detector consists of BC-400 and NaI:Tl with decay time constants of 2.4 and 230 ns, respectively.The BC-400 scintillator detects beta particles, and the Na I:Tl cell is used for gamma detection. Geant4 simulations of this phoswich detector find that a 2-mm-thick BC-400 scintillator can absorb nearly all of the beta particles whose energies are below 700 keV. Further, for a 2.00-cmthick NaI:Tl crystal, the gamma source peak efficiency for photons ranges from a maximum of nearly 90% at 30 keV to 10% at 1 MeV. The self-absorption effect is also discussed in this paper in order to determine the carrier gas' s influence.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22373063 and 22302005)Fundamental Research Funds for the Central Universities of China(No.GK202203002)+1 种基金China Postdoctoral Science Foundation(No.2023M730044)Technology Innovation Leading Program of Shaanxi(Program No.2023KXJ-007).
文摘Deep insights into electrocatalytic mechanisms are vital for the rational design of catalysts for oxygen evolution reaction(OER).Mechanistically,the OER driven by adsorbate evolution mechanism(AEM)is limited by the linear scaling relationship,thereby exhibiting large overpotentials.In the lattice oxygen mechanism(LOM),the OER can be enhanced by enabling direct O_(2)formation.However,this enhancement is accompanied by the generation of oxygen vacancies,which presents a significant challenge to the long-term stability of LOMOER,particularly when operating at high current densities.Recently,the*O-*O coupling mechanism(OCM)has emerged as a promising alternative;it not only breaks the linear scaling relationship but also ensures catalytic stability.This review encapsulates the cutting-edge advancements in electrocatalysts that are grounded in the OCM,offering a detailed interpretation on the foundational principles guiding the design of OCM-OER catalysts.It also highlights recent theoretical investigations combining machine learning(ML)with density functional theory(DFT)calculations to reveal OER mechanisms.At the end of this review,the challenges and opportunities associated with OCM-OER electrocatalysts are discussed.
基金funded by the National Key Research and Development Program of China(2024YFD1201202)the Major Program of National Agricultural Science and Technology of China(NK20220607)+1 种基金the Science and Technology Bureau of Sichuan Province(2023NSFSC1995,2024NSFSC1968,and 2025YFHZ0184)the Science and Technology Bureau of Chengdu City(2024-YF05-00368-SN)。
文摘Psathyrostachys huashanica Keng ex P.C.Kuo(2n=2x=14,NsNs),a wild relative of wheat,represents a valuable germplasm resource for genetic improvement of wheat.We previously confirmed that a chromosome 7Ns from P.huashanica carries genes that accelerate heading and maturity in wheat.Here,we developed three small segment translocation lines(T7NsS-2BL 2BS,T7NsS-1AS 1AL#1,and T7NsS-1AS 1AL#2)along with one additional small segment translocation line(T7NsS-7BS 7BL)through^(60)Co-γ irradiation,identified using genomic in situ hybridization(GISH),fluorescence in situ hybridization(FISH),and liquid chip array analyses.Our findings demonstrated that chromosome 7NsS contained a major early heading date gene,tentatively designated Ehd-7Ns,which was mapped to an approximate31.45 Mb region,corresponding to the short arm of wheat chromosome 7A(IWGSC RefSeq v1.0).The T7NsS-1AS 1AL#2 line exhibited no significant yield penalty and possessed superior agronomic traits relative to the other translocation lines in the field,making it a promising pre-breeding donor for breeding early maturing wheat.Furthermore,21 specific Kompetitive Allele Specific PCR(KASP)markers were developed based on transcriptome data,enabling effective tracing of alien chromosomal segments carrying this source of Ehd-7Ns in marker-assisted breeding.Collectively,these newly developed translocation lines and specific KASP markers will facilitate the transfer and utilization of favorable genes from P.huashanica chromosome 7Ns in future wheat breeding programs.
文摘Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,energy,materials,quantum,and microelectronics.Surface science mainly investigates the correspondence between surface property and functionality.Scanning probe microscopy(SPM)techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging,spectroscopy and manipulation at the single-atom level.In this review,we summarize recent advances in surface electronic,magnetic and optical properties characterized mainly by SPM-based methods.We focus on elucidating theπ-magnetism in graphene-based nanostructures,construction of spin qubits on surfaces,topology properties of surface organic structures,STM-based light emission,tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.
基金supported by the National Natural Science Foundation of China(31971883 and 32200180)the Major Program of National Agricultural Science and Technology of China(NK20220607)+2 种基金the Special Projects of the Central Government in Guidance of Local Science and Technology Development,China(2023ZYD0088)the Science and Technology Bureau of Sichuan Province,China(2021YFYZ0002,2022ZDZX0014,2023NSFSC1995,and 2022YFSY0035)the Science and Technology Bureau of Chengdu City,China(2022-YF05-00449-SN).
文摘Fusarium head blight(FHB),mainly caused by Fusarium graminearum,is one of the most destructive fungal diseases affecting global wheat production.Elymus repens(2n=6×=42,StStStStHH),a wild relative of wheat,exhibits numerous biotic and abiotic stress resistance characteristics.In previous studies,FHB resistance of E.repens has been transferred into common wheat through a wheat-E.repens partial amphidiploid and derivative lines.This study reports the development,characterization,and breeding utilization of K140-7,a novel wheat-E.repens translocation line conferring resistance to FHB.Genomic in situ hybridization(GISH)and fluorescence in situ hybridization(FISH)analyses demonstrated that K140-7 contained 40 common wheat chromosomes and two 7D·St translocation chromosomes.Subsequent characterization using oligonucleotide-FISH painting and single-gene FISH markers confirmed that the 7D fragment was a 7D short arm and the St fragment was a 7St long arm.Therefore,K140-7 was further identified as a 7DS·7StL translocation line with genetic compensation.Wheat 55K SNP array analysis of K140-7 demonstrated the 7DS·7StL translocation event.Field evaluations demonstrated that K140-7 exhibits agronomic performance comparable to its wheat parent.Based on St reference genome of Pseudoroegneria libanotica,21 simple sequence repeats(SSR)markers specific to 7StL were developed.Genetic analysis established that 7StL confers FHB resistance and carries the dominant FHB resistance locus,designated as QFhb.Er-7StL.Introgression of QFhb.Er-7StL into elite wheat cultivars has generated three second-generation 7DS·7StL translocation lines with enhanced agronomic traits.This study provides valuable novel germplasms and specific molecular markers for FHB resistance breeding in wheat.
基金funded by the Natural Science Foundation of Sichuan Province for Young Scholars(2024NSFSC1218)the HighLevel Talent Introduction Project of Sichuan Academy of Agricultural Sciences(NKYRCZX2024022)+1 种基金the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance Department(1+3 ZYGG001)the Strategic Scientist Studio of Sichuan Academy of Agricultural Sciences.
文摘Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.
基金supported by the National High Technology Research and Development Program (863) of China (No.2010AA064904)
文摘Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated. The catalysts before and after reaction were characterized by BET, CO chemisorption, XRD and XPS techniques. Results showed that the presence of Ce significantly increased the activity and thermal stability of the Pd-Pt/Al2O3 catalyst towards methane combustion, which could be attributed to more highly-dispersed active PdO particles over the Pd-Pt/Ce/Al2O3 catalyst surface as well as the retarded sintering of PdO and the maintained oxidized state of surface Pd during the combustion process in the presence of Ce.
基金supported by the Natinal Science Foundation (NSFC 21006130)the Key Research Programs of Chongqing Science and Technology Commission Foundation (CSTC,2009AB4012)
文摘Promoted catalytic reaction between methanol and CO2 for dimethyl carbonate （DMC） synthesis is conducted over K2CO3/CH3I catalyst in the presence of ionic liquid under microwave irradiation. The effect of ionic liquids incorporated with microwave irradiation on the yield of DMC is investigated. DMC was found to form at lower temperature in a relative short time, which indicated an enhanced catalytic process by ionic liquid. Among the ionic liquids used, 1-butyl-3-methylimidazolium chloride is the most effective promoter. Density functional theory calculations indicate that CO2 bond lengths and angles changed due to the molecular interaction of ionic liquid and CO2, resulting in the activation of CO2 molecules and consequently the acceleration of reaction rate.
基金supported by the National Natural Science Foundation of China(Nos.11205108,11475121,and 11575145)the Excellent Youth Fund of Sichuan University(No.2016SCU04A13)
文摘In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich detector is of the semi-well type, so it has a higher detection efficiency. The detector consists of BC-400 and NaI:Tl with decay time constants of 2.4 and 230 ns, respectively.The BC-400 scintillator detects beta particles, and the Na I:Tl cell is used for gamma detection. Geant4 simulations of this phoswich detector find that a 2-mm-thick BC-400 scintillator can absorb nearly all of the beta particles whose energies are below 700 keV. Further, for a 2.00-cmthick NaI:Tl crystal, the gamma source peak efficiency for photons ranges from a maximum of nearly 90% at 30 keV to 10% at 1 MeV. The self-absorption effect is also discussed in this paper in order to determine the carrier gas' s influence.
