Northern China is a prominent “hotspot” for land–atmosphere interactions, with substantial gradients in both moisture and thermal conditions. Previous studies have identified a link between land–atmosphere couplin...Northern China is a prominent “hotspot” for land–atmosphere interactions, with substantial gradients in both moisture and thermal conditions. Previous studies have identified a link between land–atmosphere coupling and the individual roles of each factor, but the synergistic effect of the two factors remains unclear. This study considers the covariation of evapotranspiration and precipitation to assess evapotranspiration–precipitation(ET–P) coupling across northern China,exploring its spatial variations and their linkage to water and heat factors. Our findings reveal a transition from strongly positive coupling in the northwest to weakly negative coupling in the southeast, peaking in spring. These spatial variations are attributable to water(soil moisture) and heat(air temperature), which explain 39% and 25% of the variability,respectively. The aridity index(AI), a water–heat synergy factor, is the dominant factor, explaining 66% of the spatial variation in ET–P coupling. As the AI increases, ET–P coupling shifts from strongly positive to weakly negative, with an AI around 0.7. This shift is determined by a shift in the evapotranspiration–lifting condensation level(LCL) coupling under an AI change. Regions with an AI below 0.7 experience water-limited evapotranspiration, where increased soil moisture enhances evapotranspiration, reduces sensible heat(H), and lowers the LCL, resulting in a negative ET–LCL coupling.Conversely, regions with an AI above 0.7 experience energy-limited evapotranspiration, where the positive ET–LCL coupling reflects a positive H–LCL coupling or a positive impact of the LCL on evapotranspiration. This analysis advances our understanding of the intricate influences of multifactor surface interactions on the spatial variations of land–atmosphere coupling.展开更多
Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study inve...Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(HEMTs).Under a high voltage,the HEMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the devices.In addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect occurred.Additionally,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without bias.The latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN layer.Moreover,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel analysis.The accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and failure.This study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.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
The hot deformation behavior of magnesium(Mg)alloys is significantly governed by the multi-physics coupling effects of temperature(T),strain rate(ε)and strain(ε),resulting in flow behavior that exhibits pronounced n...The hot deformation behavior of magnesium(Mg)alloys is significantly governed by the multi-physics coupling effects of temperature(T),strain rate(ε)and strain(ε),resulting in flow behavior that exhibits pronounced nonlinearity and multi-scale complexity.This study systematically investigates the hot deformation behavior of Mg-Y-Nd-(Sm)-Zr alloys.Sm alloying promotes recrystallization.The flow stress of Sm-containing alloys declines sharply towards a steady state after reaching its peak value.To overcome the limitations of the Arrhenius-type constitutive(AC)model in predicting complex nonlinear flow behavior,the AC and data hybrid informed neural network(ACINN)model is developed.This approach enhances the predictive accuracy and extends the applicability of the traditional AC model.The evolution of microstructure and recrystallization behavior under hot deformation conditions are investigated based on results from electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).The relationship between the power dissipation factor(η)and recrystallization behavior is further examined using K-means clustering analysis.The results demonstrate that dynamic recrystallization(DRX)behavior varies with theηvalue,comprising four distinct regimes:dynamic recovery(DRV),discontinuous dynamic recrystallization(DDRX)dominance,continuous dynamic recrystallization(CDRX)dominance and complete dynamic recrystallization.This analysis presents a new perspective for studying the hot deformation processes of Mg alloys.展开更多
Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change o...Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change of China were published in 2020 and 2022, respectively.However, no concrete results on the long-term trends in wave changes in China have been obtained. In this study, long-term trends in extreme wave elements over the past 55 years were investigated using wave data from five in situ observation sites(i.e., Lao Hu Tan, Cheng Shan Tou,Ri Zhao, Nan Ji, Wei Zhou) along the coast of China. The five stations showed different trends in wave height. Results show a general downward trend in wave heights at the LHT and CST stations, reaching-0.78 and-1.44 cm/a, respectively, in summer at middle and high latitudes. NJI stations at middle-to-low latitudes are influenced by the winter monsoon and summer tropical cyclones, showing a substantial increase in extreme wave heights(0.7 cm/a in winter and 2.68 cm/a in summer). The cumulative duration of H_(1/10) ≥ 3 m at NJI and RZH has grown since 1990.展开更多
Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is...Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is still lacking.This study employed a rolled AZ31B plate with typical basal texture to investigate the shear behaviors.Positive and negative simple shear experiments were performed at different angles in the transverse plane,whereby the visco-plastic self-consistent model was calibrated to reveal the deformation mechanisms and predict the mechanical responses at various orientations.Positive-negative shear asymmetry is present because extension twinning preferentially operates in one shear direction but is suppressed in the opposite direction.Simple shear induces multiple twin variants,thus impedes twin growth and slows the consumption of matrix,as compared to in-plane compression.For slip dominated simple shear,the interaction between loading-induced rigid body rotation and slip-induced crystal rotation produces distinct hardening behaviors,namely orthogonally asymmetric mechanical responses at complementary loading angles,which is largely absent in uniaxial loading.Finally,simulation results verify that positive-negative shear asymmetry appears only when the deviatoric normal stress on the sheet plane is non-zero.Positive-negative shear asymmetry persists except for the conditions of shear plane parallel to sheet plane,or shear direction parallel or perpendicular to rolling direction.展开更多
Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use...Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.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
Zeolitic imidazole frameworks(ZIFs)are a class of three-dimensional(3D)skeletalmaterials with zeolitic topology composed of metal ions and imidazolium ligands,which combine the advantages of zeolites and metal-organic...Zeolitic imidazole frameworks(ZIFs)are a class of three-dimensional(3D)skeletalmaterials with zeolitic topology composed of metal ions and imidazolium ligands,which combine the advantages of zeolites and metal-organic frameworks.ZIFs are widely used for adsorption of carbon dioxide(CO_(2))from flue gas due to its excellent hydrophobicity,chemical stability,thermal stability and gas adsorption properties.This study focuses on the effects of structures of ZIFs on CO_(2)capture and separation from the viewpoints of topologies,pore channels,ligand functional groups and composite structures.On this basis,the mechanisms of CO_(2)adsorption and selective separation are reviewed,as well as the challenges such as hydrophobicity,thermal and chemical stability faced by ZIFs in practical applications.展开更多
The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged...The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged parts was investigated.In the present work,3D processing maps are established,and the forming domain that is both stable and power efficient is in the temperature range from 430 to 500℃ and strain rate range from 0.001 to 0.06 s^(-1),which is used to guide the single-directional forging(SDF)and multi-directional forging(MDF)experiments.The tensile mechanical properties reveal that the blocky LPSO particles have an influence on the mechanical anisotropy,especially in terms of the elongation anisotropy.The blocky LPSO particles after the MDF process have a more regular shape and smaller size and are homogeneously distributed,which is responsible for the low anisotropy of the elongation.In addition,the age-hardening capability of the MDF part is higher than that of the SDF part.展开更多
High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-p...High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-proof alloy design.This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure,and also the mechanisms of alloying elements improving the ignition resistance.The low strength is another reason restricting the development of Mg alloys.Therefore,at the last section,Mg alloys with the combination of high strength and good ignition-proof performance are summarized,including Mg-Al-Ca based alloys,SEN(Mg-Al-Zn-Ca-Y)alloys as well as Mg-Y and Mg-Gd based alloys.Besides,the shortages and the future focus of theses alloys are also reviewed.The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.展开更多
Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)converts CO_(2)into valuable chemical fuels,which can effectively alleviate global warming and energy crisis.However,limited by its slow reaction rate and low product...Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)converts CO_(2)into valuable chemical fuels,which can effectively alleviate global warming and energy crisis.However,limited by its slow reaction rate and low product selectivity,it is urgent to design efficient,cheap,safe,and highly selective CO_(2)RR electrocatalysts.Owing to the advantages of adjustable electronic structure,abundant active sites,low cost,environmental friendliness and excellent electrochemical performance,bimetallic chalcogenides have aroused great interest.Here,we briefly summarized different bimetallic oxides and sulfides for electrocatalytic CO_(2)RR in the past five years.In addition,different hybridizations formed between metal atoms,including intermetallic compounds,heterostructures and metal doping,were generalized.Their positive effects on CO_(2)RR catalytic selectivity and activity were deeply uncovered.Besides,we also put forward some views about the future research directions and perspectives in CO_(2)RR field.This review aims to provide a reference for the rational design of bimetallic chalcogenides towards electrocatalytic CO_(2)reduction.展开更多
Although synthetic rubbers show continuously improved mechanical properties,natural rubber (NR) remains irreplaceable in the rubber family due to its superior mechanical properties.A mainstream viewpoint regarding the...Although synthetic rubbers show continuously improved mechanical properties,natural rubber (NR) remains irreplaceable in the rubber family due to its superior mechanical properties.A mainstream viewpoint regarding the superiority of NR is that NR possesses a natural network formed by linking the poly(cis-l,4-isoprene) chain terminals to protein and phospholipid aggregates;after vulcanization,the natural network additionally contributes to rubber mechanics by both increasing the network density and promoting the strain-induced crystallization (SIC) behavior.However,the reason why the natural network promotes SIC is still unclear;in particular,only using the increased network density cannot explain our finding that the NR shows smaller onset strain of SIC than Gel (the gel component of NR with higher network density) and even vulcanized NR.Herein,we point out that the inhomogeneous chain deformation is the alternative reason why SIC of NR takes place at smaller strain than that of Gel.More specifically,although the natural network is homogenous on the subchain length scale based on the proton double-quantum NMR results,it is essentially inhomogeneous on mesoscale (100 nm),as revealed by the small angle X-ray scattering analysis.This inhomogeneous network also leads to the mesoscale deformation inhomogeneity,as detected by the orientation of stearic acid (SA) probe,thus resulting in the smaller onset strain of SIC of NR.Based on the experimental results,a mesoscale model is proposed to qualitatively describe the crucial roles of inhomogeneous structure and deformation of natural network in NR?s mechanical properties,providing a clue from nature to guide the development of high-performance rubbers with controlled structures at mesoscale.展开更多
Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroi...Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroidal anti-inflammatory drugs(NSAIDs),corticosteroids,antiantibodies,and small molecular drugs(DMARDs),and they are clinically in vogue for diseases such as rheumatoid arthritis(RA).Nevertheless,low cost-effectiveness,reduced efficacy,adverse effects,and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod.Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics.However,its efficacy against other autoimmune ailments is also under intense investigation,and the number of investigations is becoming increasingly larger with each passing day.The articular structure comprises synovium,ligaments,and bone.The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body.Therefore,its protection is also of prime importance in RA and other autoimmune diseases.Herein,we have highlighted the role of iguratimod in autoimmune diseases and bone protection.We suggest that iguratimod’s unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.展开更多
Ticks are considered the second most common pathogen vectors transmitting a broad range of vital human and veterinary viruses.From 2017 to 2018,640 ticks were collected in eight different provinces in central and west...Ticks are considered the second most common pathogen vectors transmitting a broad range of vital human and veterinary viruses.From 2017 to 2018,640 ticks were collected in eight different provinces in central and western China.Six species were detected,including H.longicornis,De.everestianus,Rh.microplus,Rh.turanicus,Rh.sanguineous,and Hy.asiaticum.Sixty-four viral metagenomic libraries were constructed on the MiSeq Illumina platform,resulting in 13.44 G(5.88×10^(7))of 250-bp-end reads,in which 2,437,941 are viral reads.We found 27 nearly complete genome sequences,including 16 genome sequences encoding entire protein-coding regions(lack of 30 or 50 end non-coding regions)and complete viral genomes,distributed in the arboviral family(Chuviridae,Rhabdoviridae,Nairoviridae,Phenuiviridae,Flaviviridae,Iflaviridae)as well as Parvoviridae and Polyomaviridae that cause disease in mammals and even humans.In addition,13 virus sequences found in Chuviridae,Nairoviridae,Flaviviridae,Iflaviridae,Hepeviridae,Parvoviridae,and Polyomaviridae were identified as belonging to a new virus species in the identified viral genera.Besides,an epidemiological survey shows a high prevalence(9.38%and 15.63%)of two viruses(Ovine Copiparvovirus and Bovine parvovirus 2)in the tick cohort.展开更多
Designing non-noble metal electrocatalysts toward alkaline hydrogen evolution reaction(HER)with high performance at a large current density is urgent.Herein,a CoO/CoP heterostructure catalyst(termed POZ)was designed b...Designing non-noble metal electrocatalysts toward alkaline hydrogen evolution reaction(HER)with high performance at a large current density is urgent.Herein,a CoO/CoP heterostructure catalyst(termed POZ)was designed by a phosphating strategy.The strong electron transfer on the interface of CoO/CoP was experimentally and theoretically proven.POZ showed a low overpotential of 236 mV at 400 mA/cm^(2),which was 249 mV lower than non-phosphated sample.It also exhibited a remarkable solar-to-hydrogen conversion efficiency of 10.5%.In this work,the construction of CoO/CoP interface realized by a simple phosphating strategy could provide an important reference to boost the HER performance on those materials not merely metal oxides.展开更多
Single atom catalysts(SACs) with isolated metal atoms dispersed on supports exhibit distinctive performances for electrocatalysis reactions.The designable realization of well-dispersed single metal atoms is still a gr...Single atom catalysts(SACs) with isolated metal atoms dispersed on supports exhibit distinctive performances for electrocatalysis reactions.The designable realization of well-dispersed single metal atoms is still a great challenge owing to their ease of aggregation.Here,Mo single atomic sites(Mo-N_(3)C)combined with some ultrasmall Mo_(2)C/MoN clusters(Mo-SA/Mo_(2)C-MoN-Cs,mean diameter <2 nm) on nitrogen-doped porous carbon were synthesized via a simple pyrolysis of bimetallic Zn/Mo metalorganic frameworks.X-ray absorption near edge spectra(XANES) in combination with various characterizations show that most of Mo species in sample exist in the form of single sites and the exact structure is Mo-N_(3)C.Density functional theory(DFT) calculation further shows that as the number of Ncoordination in the Mo-NxC moieties increases,the positive cha rge of Mo atoms increases.The single Mo atoms in Mo-N_(3)C have the best capability of N_(2) adsorption,which may serve as main active sites for further electrochemical N2 reduction.展开更多
基金jointly supported by the National Science Foundation of China (Grant No.42230611)the Meteorological Joint Fund (Grant No.U2142208)+2 种基金the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (grant no.2019QZKK0102)the National Science Foundation of China (Grant No.42005071)the Gansu Province Key Talent Project (Grant No.2023RCXM37)。
文摘Northern China is a prominent “hotspot” for land–atmosphere interactions, with substantial gradients in both moisture and thermal conditions. Previous studies have identified a link between land–atmosphere coupling and the individual roles of each factor, but the synergistic effect of the two factors remains unclear. This study considers the covariation of evapotranspiration and precipitation to assess evapotranspiration–precipitation(ET–P) coupling across northern China,exploring its spatial variations and their linkage to water and heat factors. Our findings reveal a transition from strongly positive coupling in the northwest to weakly negative coupling in the southeast, peaking in spring. These spatial variations are attributable to water(soil moisture) and heat(air temperature), which explain 39% and 25% of the variability,respectively. The aridity index(AI), a water–heat synergy factor, is the dominant factor, explaining 66% of the spatial variation in ET–P coupling. As the AI increases, ET–P coupling shifts from strongly positive to weakly negative, with an AI around 0.7. This shift is determined by a shift in the evapotranspiration–lifting condensation level(LCL) coupling under an AI change. Regions with an AI below 0.7 experience water-limited evapotranspiration, where increased soil moisture enhances evapotranspiration, reduces sensible heat(H), and lowers the LCL, resulting in a negative ET–LCL coupling.Conversely, regions with an AI above 0.7 experience energy-limited evapotranspiration, where the positive ET–LCL coupling reflects a positive H–LCL coupling or a positive impact of the LCL on evapotranspiration. This analysis advances our understanding of the intricate influences of multifactor surface interactions on the spatial variations of land–atmosphere coupling.
基金supported by the National Natural Science Foundation of China(Nos.12035019,62234013,12205350,12075290,12175287)the China National Postdoctoral Program for Innovative Talents(BX20200340)+1 种基金the fund of Innovation Center of Radiation Application(No.KFZC2022020601)the Chinese Academy of Sciences(CAS)“Light of West China"Program hosted by Jian Zeng.
文摘Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(HEMTs).Under a high voltage,the HEMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the devices.In addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect occurred.Additionally,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without bias.The latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN layer.Moreover,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel analysis.The accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and failure.This study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.
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.
基金supported by the National Natural Science Foundation of China(nos.52201119,52371108)Frontier Exploration Project of Longmen Laboratory,China(no.LMQYTSKT014)The Joint Fund of Henan Science and Technology R&D Plan of China(no.242103810056).
文摘The hot deformation behavior of magnesium(Mg)alloys is significantly governed by the multi-physics coupling effects of temperature(T),strain rate(ε)and strain(ε),resulting in flow behavior that exhibits pronounced nonlinearity and multi-scale complexity.This study systematically investigates the hot deformation behavior of Mg-Y-Nd-(Sm)-Zr alloys.Sm alloying promotes recrystallization.The flow stress of Sm-containing alloys declines sharply towards a steady state after reaching its peak value.To overcome the limitations of the Arrhenius-type constitutive(AC)model in predicting complex nonlinear flow behavior,the AC and data hybrid informed neural network(ACINN)model is developed.This approach enhances the predictive accuracy and extends the applicability of the traditional AC model.The evolution of microstructure and recrystallization behavior under hot deformation conditions are investigated based on results from electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).The relationship between the power dissipation factor(η)and recrystallization behavior is further examined using K-means clustering analysis.The results demonstrate that dynamic recrystallization(DRX)behavior varies with theηvalue,comprising four distinct regimes:dynamic recovery(DRV),discontinuous dynamic recrystallization(DDRX)dominance,continuous dynamic recrystallization(CDRX)dominance and complete dynamic recrystallization.This analysis presents a new perspective for studying the hot deformation processes of Mg alloys.
基金Supported by the National Natural Science Foundation of China (No. 52271271)National Key Research and Development Program of China (No. 2022YFE0104500)Major Science and Technology Projects of the Ministry of Water Resources (No. SKS-2022025)。
文摘Extreme waves may considerably impact crucial coastal and marine engineering structures. The First Scientific Assessment Report on Ocean and Climate Change of China and The Fourth Assessment Report on Climate Change of China were published in 2020 and 2022, respectively.However, no concrete results on the long-term trends in wave changes in China have been obtained. In this study, long-term trends in extreme wave elements over the past 55 years were investigated using wave data from five in situ observation sites(i.e., Lao Hu Tan, Cheng Shan Tou,Ri Zhao, Nan Ji, Wei Zhou) along the coast of China. The five stations showed different trends in wave height. Results show a general downward trend in wave heights at the LHT and CST stations, reaching-0.78 and-1.44 cm/a, respectively, in summer at middle and high latitudes. NJI stations at middle-to-low latitudes are influenced by the winter monsoon and summer tropical cyclones, showing a substantial increase in extreme wave heights(0.7 cm/a in winter and 2.68 cm/a in summer). The cumulative duration of H_(1/10) ≥ 3 m at NJI and RZH has grown since 1990.
基金supports of the National Key Research and Development Program of China(Grant No.2023YFB3710900)the National Natural Science Foundation of China(Grant Nos.52071211 and 52071208)。
文摘Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is still lacking.This study employed a rolled AZ31B plate with typical basal texture to investigate the shear behaviors.Positive and negative simple shear experiments were performed at different angles in the transverse plane,whereby the visco-plastic self-consistent model was calibrated to reveal the deformation mechanisms and predict the mechanical responses at various orientations.Positive-negative shear asymmetry is present because extension twinning preferentially operates in one shear direction but is suppressed in the opposite direction.Simple shear induces multiple twin variants,thus impedes twin growth and slows the consumption of matrix,as compared to in-plane compression.For slip dominated simple shear,the interaction between loading-induced rigid body rotation and slip-induced crystal rotation produces distinct hardening behaviors,namely orthogonally asymmetric mechanical responses at complementary loading angles,which is largely absent in uniaxial loading.Finally,simulation results verify that positive-negative shear asymmetry appears only when the deviatoric normal stress on the sheet plane is non-zero.Positive-negative shear asymmetry persists except for the conditions of shear plane parallel to sheet plane,or shear direction parallel or perpendicular to rolling direction.
基金supported by the National Natural Science Foundation of China(U21A20236,32072664)the Natural Science Foundation of Hunan Province,China(2022RC3053,2021JC0001,2021RC3086,2022NK2009)+1 种基金the China Agriculture Research System(CARS-01-30)the Innovation Foundation for Graduate of Hunan Agricultural University,China(2023XC116)。
文摘Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.
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supported by the Fundamental Research Program of Shanxi Province(Nos.20210302124003 and 20210302124015)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2021L032)+2 种基金the National Natural Science Foundation of China(No.52103307)China Postdoctoral Science Foundation(No.2023M742575)the General Program of Shanxi Province(No.202203021211150).
文摘Zeolitic imidazole frameworks(ZIFs)are a class of three-dimensional(3D)skeletalmaterials with zeolitic topology composed of metal ions and imidazolium ligands,which combine the advantages of zeolites and metal-organic frameworks.ZIFs are widely used for adsorption of carbon dioxide(CO_(2))from flue gas due to its excellent hydrophobicity,chemical stability,thermal stability and gas adsorption properties.This study focuses on the effects of structures of ZIFs on CO_(2)capture and separation from the viewpoints of topologies,pore channels,ligand functional groups and composite structures.On this basis,the mechanisms of CO_(2)adsorption and selective separation are reviewed,as well as the challenges such as hydrophobicity,thermal and chemical stability faced by ZIFs in practical applications.
基金supports of the National Key Research and Development Program of China(Grant No.2021YFB3501005)the National Natural Science Foundation of China(Grant No.52071208)the Key R&D program of Shanxi Province(International Cooperation)(Grant No.201903D421036).
文摘The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged parts was investigated.In the present work,3D processing maps are established,and the forming domain that is both stable and power efficient is in the temperature range from 430 to 500℃ and strain rate range from 0.001 to 0.06 s^(-1),which is used to guide the single-directional forging(SDF)and multi-directional forging(MDF)experiments.The tensile mechanical properties reveal that the blocky LPSO particles have an influence on the mechanical anisotropy,especially in terms of the elongation anisotropy.The blocky LPSO particles after the MDF process have a more regular shape and smaller size and are homogeneously distributed,which is responsible for the low anisotropy of the elongation.In addition,the age-hardening capability of the MDF part is higher than that of the SDF part.
基金the financial supports from the National Key Research and Development Plan(Grant No.2021YFB3701100)the National Natural Science Foundation of China(Grant No.U2241231,No.52071206)。
文摘High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-proof alloy design.This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure,and also the mechanisms of alloying elements improving the ignition resistance.The low strength is another reason restricting the development of Mg alloys.Therefore,at the last section,Mg alloys with the combination of high strength and good ignition-proof performance are summarized,including Mg-Al-Ca based alloys,SEN(Mg-Al-Zn-Ca-Y)alloys as well as Mg-Y and Mg-Gd based alloys.Besides,the shortages and the future focus of theses alloys are also reviewed.The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.
基金financially supported by Hunan Provincial Science and Technology Plan Project(Nos.2017TP1001 and 2017JJ2347)Changsha Science and Technology Plan(No.kq1801079)+1 种基金Hunan Key Laboratory of Two-Dimensional Materials(No.2018TP1010)the National Natural Science Foundation of China(No.21776317)。
文摘Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)converts CO_(2)into valuable chemical fuels,which can effectively alleviate global warming and energy crisis.However,limited by its slow reaction rate and low product selectivity,it is urgent to design efficient,cheap,safe,and highly selective CO_(2)RR electrocatalysts.Owing to the advantages of adjustable electronic structure,abundant active sites,low cost,environmental friendliness and excellent electrochemical performance,bimetallic chalcogenides have aroused great interest.Here,we briefly summarized different bimetallic oxides and sulfides for electrocatalytic CO_(2)RR in the past five years.In addition,different hybridizations formed between metal atoms,including intermetallic compounds,heterostructures and metal doping,were generalized.Their positive effects on CO_(2)RR catalytic selectivity and activity were deeply uncovered.Besides,we also put forward some views about the future research directions and perspectives in CO_(2)RR field.This review aims to provide a reference for the rational design of bimetallic chalcogenides towards electrocatalytic CO_(2)reduction.
基金financially supported by the National Natural Science Foundation of China (No. 51333003)Special Fund for Agro-scientific Research in the Public Interest (No. 201403066-1)
文摘Although synthetic rubbers show continuously improved mechanical properties,natural rubber (NR) remains irreplaceable in the rubber family due to its superior mechanical properties.A mainstream viewpoint regarding the superiority of NR is that NR possesses a natural network formed by linking the poly(cis-l,4-isoprene) chain terminals to protein and phospholipid aggregates;after vulcanization,the natural network additionally contributes to rubber mechanics by both increasing the network density and promoting the strain-induced crystallization (SIC) behavior.However,the reason why the natural network promotes SIC is still unclear;in particular,only using the increased network density cannot explain our finding that the NR shows smaller onset strain of SIC than Gel (the gel component of NR with higher network density) and even vulcanized NR.Herein,we point out that the inhomogeneous chain deformation is the alternative reason why SIC of NR takes place at smaller strain than that of Gel.More specifically,although the natural network is homogenous on the subchain length scale based on the proton double-quantum NMR results,it is essentially inhomogeneous on mesoscale (100 nm),as revealed by the small angle X-ray scattering analysis.This inhomogeneous network also leads to the mesoscale deformation inhomogeneity,as detected by the orientation of stearic acid (SA) probe,thus resulting in the smaller onset strain of SIC of NR.Based on the experimental results,a mesoscale model is proposed to qualitatively describe the crucial roles of inhomogeneous structure and deformation of natural network in NR?s mechanical properties,providing a clue from nature to guide the development of high-performance rubbers with controlled structures at mesoscale.
基金supported by the Natural Science Foundation of Shandong Province (ZR2012HM038)the Shenzhen Science and Technology Innovation Committee Fund (JCYJ2016033117365255)+1 种基金the China International Medical Foundation (Simcere-Z2014-06-2-1635)the China Torch Program (2013GH021476)
文摘Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroidal anti-inflammatory drugs(NSAIDs),corticosteroids,antiantibodies,and small molecular drugs(DMARDs),and they are clinically in vogue for diseases such as rheumatoid arthritis(RA).Nevertheless,low cost-effectiveness,reduced efficacy,adverse effects,and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod.Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics.However,its efficacy against other autoimmune ailments is also under intense investigation,and the number of investigations is becoming increasingly larger with each passing day.The articular structure comprises synovium,ligaments,and bone.The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body.Therefore,its protection is also of prime importance in RA and other autoimmune diseases.Herein,we have highlighted the role of iguratimod in autoimmune diseases and bone protection.We suggest that iguratimod’s unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.
基金funded by the National Key Research and Development Programs of China(No.2022YFC2603800)Jiangsu Provincial Key Research and Development Projects(No.BE2017693).
文摘Ticks are considered the second most common pathogen vectors transmitting a broad range of vital human and veterinary viruses.From 2017 to 2018,640 ticks were collected in eight different provinces in central and western China.Six species were detected,including H.longicornis,De.everestianus,Rh.microplus,Rh.turanicus,Rh.sanguineous,and Hy.asiaticum.Sixty-four viral metagenomic libraries were constructed on the MiSeq Illumina platform,resulting in 13.44 G(5.88×10^(7))of 250-bp-end reads,in which 2,437,941 are viral reads.We found 27 nearly complete genome sequences,including 16 genome sequences encoding entire protein-coding regions(lack of 30 or 50 end non-coding regions)and complete viral genomes,distributed in the arboviral family(Chuviridae,Rhabdoviridae,Nairoviridae,Phenuiviridae,Flaviviridae,Iflaviridae)as well as Parvoviridae and Polyomaviridae that cause disease in mammals and even humans.In addition,13 virus sequences found in Chuviridae,Nairoviridae,Flaviviridae,Iflaviridae,Hepeviridae,Parvoviridae,and Polyomaviridae were identified as belonging to a new virus species in the identified viral genera.Besides,an epidemiological survey shows a high prevalence(9.38%and 15.63%)of two viruses(Ovine Copiparvovirus and Bovine parvovirus 2)in the tick cohort.
基金the financial support from the Hunan Provincial Science and Technology Plan Project(Nos.2017TP1001,2020JJ4710)National Natural Science Foundation of China(No.11764018)+2 种基金the Natural Science Foundation of Jiangxi Province(No.20202ACBL211004)Changsha Science and Technology Plan(No.kq1801079)National Natural Science Foundation of China(No.21776317).
文摘Designing non-noble metal electrocatalysts toward alkaline hydrogen evolution reaction(HER)with high performance at a large current density is urgent.Herein,a CoO/CoP heterostructure catalyst(termed POZ)was designed by a phosphating strategy.The strong electron transfer on the interface of CoO/CoP was experimentally and theoretically proven.POZ showed a low overpotential of 236 mV at 400 mA/cm^(2),which was 249 mV lower than non-phosphated sample.It also exhibited a remarkable solar-to-hydrogen conversion efficiency of 10.5%.In this work,the construction of CoO/CoP interface realized by a simple phosphating strategy could provide an important reference to boost the HER performance on those materials not merely metal oxides.
基金the financial support from the Hunan Provincial Science and Technology Plan Project(Nos.2017TP1001,2020JJ4710)the National Natural Science Foundation of China(No.21603109)+3 种基金the Henan Joint Fund of the National Natural Science Foundation of China(No.U1404216)the postdoctoral research funding plan in Central SouthUniversity(No.140050022)the Fundamental Research Funds for the Central Universities(No.DUT20RC(3)021)the 1W1B station for XAFS measurements in Beijing Synchrotron Radiation Facility(BSRF)。
文摘Single atom catalysts(SACs) with isolated metal atoms dispersed on supports exhibit distinctive performances for electrocatalysis reactions.The designable realization of well-dispersed single metal atoms is still a great challenge owing to their ease of aggregation.Here,Mo single atomic sites(Mo-N_(3)C)combined with some ultrasmall Mo_(2)C/MoN clusters(Mo-SA/Mo_(2)C-MoN-Cs,mean diameter <2 nm) on nitrogen-doped porous carbon were synthesized via a simple pyrolysis of bimetallic Zn/Mo metalorganic frameworks.X-ray absorption near edge spectra(XANES) in combination with various characterizations show that most of Mo species in sample exist in the form of single sites and the exact structure is Mo-N_(3)C.Density functional theory(DFT) calculation further shows that as the number of Ncoordination in the Mo-NxC moieties increases,the positive cha rge of Mo atoms increases.The single Mo atoms in Mo-N_(3)C have the best capability of N_(2) adsorption,which may serve as main active sites for further electrochemical N2 reduction.
