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Foliar nano-molybdenum application mitigates cadmium-induced apoplastic H_(2)O_(2)burst in rice roots by optimizing the antioxidant system
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作者 lin Tao Wenyi Pan +8 位作者 Jing li Xiaole Chen Yalin li xuewen li Jiayou liu Sergey Shabala Xuecheng Sun Fangbai li Min Yu 《The Crop Journal》 2025年第6期1827-1841,共15页
Cadmium(Cd^(2+))exhibits pronounced phytotoxicity and poses significant risks to human health through bioaccumulation in agricultural products.This study investigates the mitigative effects of foliar-applied nano-moly... Cadmium(Cd^(2+))exhibits pronounced phytotoxicity and poses significant risks to human health through bioaccumulation in agricultural products.This study investigates the mitigative effects of foliar-applied nano-molybdenum particles(MoNPs)on Cd accumulation and growth rates in rice(Oryza sativa).Our findings demonstrate that MoNPs application effectively alleviates Cd-induced root growth suppression and reduces Cd deposition in root cell walls,through MoNPs-mediated attenuation of Cd-induced elevation of pectin content.Through cross-sectional analysis combined with ROS-specific fluorescent probes revealed a spatial pattern of Cd-induced H_(2)O_(2)accumulation,with strongest signals observed in the apoplastic regions of root elongation and maturation zones,with minimal accumulation in meristematic regions.This oxidative burst was significantly mitigated by MoNPs treatment,which enhanced plasma membrane(PM)-localized respiratory burst oxidase homolog(RBOH)activity via transcriptional upregulation of OsRBOH genes.Furthermore,foliar MoNPs application activated the ascorbate–glutathione(ASA-GSH)cycle through selective upregulation of OsAPXs and OsGRs,enhancing cellular capacity for H_(2)O_(2)detoxification.These coordinated mechanisms collectively suggest that MoNPs treatment offers dual protection against Cd toxicity by 1)reducing Cd bioavailability in plant tissues and 2)counteracting Cd-induced oxidative damage,thereby effectively ameliorating root growth inhibition under Cd stress. 展开更多
关键词 CADMIUM Apoplastic H_(2)O_(2) RBOH MoNPs Rice
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In-situ 3D visualizations of microstructural evolution during hot-pressing sintering of 7055 alloy powders containing satellite particles
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作者 Kesong Miao Rui Yao +6 位作者 Chenglin Wang Yi Ma Hao Wu xuewen li Chenglu liu Rengeng li Guohua Fan 《Journal of Materials Science & Technology》 2025年第4期113-125,共13页
In this study,we developed an in-situ hot-pressing sintering(HPS)device that can be coupled to a lab-oratory X-ray microscope,offering laboratory-available observation of the morphology evolution.With the help of this... In this study,we developed an in-situ hot-pressing sintering(HPS)device that can be coupled to a lab-oratory X-ray microscope,offering laboratory-available observation of the morphology evolution.With the help of this device,in-situ three-dimensional(3D)visualizations of the microstructural evolution of 7055 aluminum alloys during the HPS process were conducted.The 3D results revealed that the twodimensional(2D)methods usually underestimated sintering neck width and exhibited significant standard deviation in statistical analysis.Benefiting from the precise microstructure characterization of the insitu 3D methods,the diffusion activation energy for the sintering of 7055 alloys was calculated,and the quantitative relationship between the sintering temperature and the sintering process was constructed.Moreover,it was experimentally found an accelerative effect of satellite particles on the sintering process,and its mechanisms were discussed.The satellite particles enhanced the curvature near the sintering neck and thus increased the sintering driving stress,promoting the densification process.These findings provide new insights for optimizing sintering processes. 展开更多
关键词 Laboratory X-ray microscope Three-dimensional tomography Hot pressing Aluminum alloy
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GLMCNet: A Global-Local Multiscale Context Network for High-Resolution Remote Sensing Image Semantic Segmentation
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作者 Yanting Zhang Qiyue liu +4 位作者 Chuanzhao Tian xuewen li Na Yang Feng Zhang Hongyue Zhang 《Computers, Materials & Continua》 2026年第1期2086-2110,共25页
High-resolution remote sensing images(HRSIs)are now an essential data source for gathering surface information due to advancements in remote sensing data capture technologies.However,their significant scale changes an... High-resolution remote sensing images(HRSIs)are now an essential data source for gathering surface information due to advancements in remote sensing data capture technologies.However,their significant scale changes and wealth of spatial details pose challenges for semantic segmentation.While convolutional neural networks(CNNs)excel at capturing local features,they are limited in modeling long-range dependencies.Conversely,transformers utilize multihead self-attention to integrate global context effectively,but this approach often incurs a high computational cost.This paper proposes a global-local multiscale context network(GLMCNet)to extract both global and local multiscale contextual information from HRSIs.A detail-enhanced filtering module(DEFM)is proposed at the end of the encoder to refine the encoder outputs further,thereby enhancing the key details extracted by the encoder and effectively suppressing redundant information.In addition,a global-local multiscale transformer block(GLMTB)is proposed in the decoding stage to enable the modeling of rich multiscale global and local information.We also design a stair fusion mechanism to transmit deep semantic information from deep to shallow layers progressively.Finally,we propose the semantic awareness enhancement module(SAEM),which further enhances the representation of multiscale semantic features through spatial attention and covariance channel attention.Extensive ablation analyses and comparative experiments were conducted to evaluate the performance of the proposed method.Specifically,our method achieved a mean Intersection over Union(mIoU)of 86.89%on the ISPRS Potsdam dataset and 84.34%on the ISPRS Vaihingen dataset,outperforming existing models such as ABCNet and BANet. 展开更多
关键词 Multiscale context attention mechanism remote sensing images semantic segmentation
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Effects of the layer thickness ratio on the enhanced ductility of laminated aluminum 被引量:3
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作者 Yiping Xia Hao Wu +5 位作者 Kesong Miao xuewen li Chao Xu lin Geng Honglan Xie Guohua Fan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第16期256-267,共12页
The layered structural parameters have been reported to be critical for tuning the tensile properties of laminated metals.Here,we investigated the effects of the thickness ratio(rc/f)of coarse-grained layers(CLs)to fi... The layered structural parameters have been reported to be critical for tuning the tensile properties of laminated metals.Here,we investigated the effects of the thickness ratio(rc/f)of coarse-grained layers(CLs)to fine-grained layers(FLs)on the enhanced ductility of the laminated Al.The local strain evolution demonstrates that the strain delocalization ability of laminated Al is improved with the decrease of rc/f.The interfacial strain gradients,which can produce extra work hardening,gradually approach and cover the CLs with the rc/fdecreasing,explaining the trend of uniform elongation in laminated Al with various rc/f.The integrated fracture morphology characterization reveals that the increase of the rc/fleads to an improvement in the tolerance of the interfacial microcracks,which is corresponding to the variation of fracture elongation in the laminated Al.Moreover,there is an evident transition of transverse propagation path of interfacial microcracks from the CLs to FLs with increasing the rc/f.Based on a geometrical criterion of microcracks connectivity,the preferential transverse propagation path of interfacial microcracks in these laminated Al was rationalized.The calculation based on this criterion also predicted the critical rc/fcorresponding to the optimal combination of strength and fracture elongation.This work deepens the understanding of the role of structural parameters of laminated metals in achieving the strength and ductility synergy. 展开更多
关键词 Layered structure Structural parameter Digital image correlation Crack propagation
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Vacuum wetting of Ag/TA2 to develop a novel micron porous Ti with significant biocompatibility and antibacterial activity 被引量:2
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作者 Guanpeng liu Yulong li +7 位作者 Ming Yan Jicai Feng Jian Cao Min Lei Quanwen liu Xiaowu Hu Wenqin Wang xuewen li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第21期180-191,共12页
Porous Ti with low modulus,excellent bio-corrosion resistance,biocompatibility,and antibacterial activity is highly pursued as advanced implant materials.In this work,a new approach to prepare micron porous structures... Porous Ti with low modulus,excellent bio-corrosion resistance,biocompatibility,and antibacterial activity is highly pursued as advanced implant materials.In this work,a new approach to prepare micron porous structures on the surface layer of a grade 2 commercially-pure Ti(TA2)was proposed,which utilized a simple vacuum wetting process of pure Ag on the surface of TA2.The microstructure,corrosion resistance,biocompatibility,mechanical properties,antibacterial ability,and formation mechanism of the asfabricated porous Ti were studied.The results show that the pores(with average pore sizes of 0.5-5μm)are distributed on the surface layer of the TA2 with a depth of~10μm.In particular,a large number of silver nanoparticles(Ag NPs)form which are dispersed on the porous structures.The formation mechanisms of the porous structures and Ag NPs were elucidated,suggesting that the volatilization/sublimation of Ag in TA2 is crucial.The porous Ti possesses excellent bio-corrosion resistance,surface wettability,biocompatibility,antibacterial activity,and a relatively low elastic modulus of 40-55 GPa,which may have a promising future in the field of orthopedic implants.This work also provides a novel idea for the development of advanced porous Ti materials for orthopedic-related basic research and biomedical applications. 展开更多
关键词 Porous titanium BIOMATERIALS Vacuum wetting Porous surface Antibacterial activity
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Responses of Wheat Production, Quality, and Soil Profile Properties to Biochar Applied at Different Seasons in a Rice-Wheat Rotation
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作者 lipei Chen Rilie Deng +2 位作者 xuewen li Min Yu Hongdong Xiao 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第12期3359-3370,共12页
In the rice-wheat rotation system,biochar(BC)can be applied at the initiation of the rice or wheat season.Here,we compared the effects of BC that were applied at two different crop seasons on wheat production,quality,... In the rice-wheat rotation system,biochar(BC)can be applied at the initiation of the rice or wheat season.Here,we compared the effects of BC that were applied at two different crop seasons on wheat production,quality,and soil profile properties in a rice-wheat rotation system with nitrogen(N)fertilizer applied at 280 kg/ha rate.Results showed that both wheat grain production and N recovery use efficiency were influenced by BC applied at two crop seasons.Biochar application did not affect the total non-essential amino-acid,but when applied during wheat season,BC significantly(p<0.05)increased total essential amino acid in grain by 12.3%,particularly for the valine(+48.2%),methionine(+43.8%),and isoleucine(+10.3%).We found that BC significantly(p<0.05)decreased the pH of soil at 0–6 cm and 20–30 cm by 0.14–0.18 and 0.05–0.08 units,respectively.The NH4+-N content of the whole observed soil profile were reduced by BC application,however,the effect of BC on NO3–-N content varied with the application season and profile depth.Interestingly,BC applied at wheat and rice season significantly(p<0.05)improved topsoil N contents by 48.4%and 19.7%,respectively.In addition,data suggested that BC applied during wheat season performed better in enhancing soil available phosphorus,potassium,and organic matter contents.In conclusion,we suggest that the optimum application time of BC for enhancing crop production and quality(take amino-acid content for example)and improving soil fertility is at the initiation of the wheat season. 展开更多
关键词 AMINO-ACID BIOCHAR paddy soil rice-wheat rotation soil fertility soil organic matter
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The MdMYB306-MdERF114 module promotes tolerance to cadmium by regulating MdATG16 in apple
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作者 Yusong liu Yiwei Jia +6 位作者 Yuhao li Jifa Han Qianwei liu xuewen li Zhijun Zhang Chao li Fengwang Ma 《Journal of Integrative Agriculture》 2025年第7期2640-2654,共15页
Cadmium(Cd)stress is a serious threat to apple growth and development.Ethylene response factors(ERFs)are a major family of transcription factors(TFs)that play a key role in the resistance to Cd stress.In this study,we... Cadmium(Cd)stress is a serious threat to apple growth and development.Ethylene response factors(ERFs)are a major family of transcription factors(TFs)that play a key role in the resistance to Cd stress.In this study,we found that the ERF TF Md ERF114 was induced in response to Cd stress.The overexpression of Md ERF114 in apple(Malus domestica)roots reduced the accumulation of Cd in the plants and enhanced their tolerance to Cd stress.Yeast one-hybrid(Y1H)assays,dual-luciferase assays,and electrophoretic mobility shift assays indicated that MdERF114 directly binds to the promoter of MdATG16 and activates its expression to increase autophagic activity,which leads to higher resistance to Cd stress.In addition,MdMYB306 interacts with MdERF114 and enhances the resistance to Cd stress by promoting the binding of MdERF114 to the promoter of MdATG16.Our findings reveal an important mechanism by which MdMYB306-MdERF114-MdATG16 influences the resistance of apple to Cd stress. 展开更多
关键词 APPLE MdERF114 MdATG16 MdMYB306 Cd stress AUTOPHAGY
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Selective oxidation of glycerol in a base-free aqueous solution: A short review 被引量:8
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作者 lihua Yang xuewen li +1 位作者 Ping Chen Zhaoyin Hou 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第7期1020-1034,共15页
Catalytic transformation of glycerol to value-added products has attracted the attention of scientists all over the world. Among various transformations, selective oxidation of glycerol with molecular oxygen to dihydr... Catalytic transformation of glycerol to value-added products has attracted the attention of scientists all over the world. Among various transformations, selective oxidation of glycerol with molecular oxygen to dihydroxyacetone, glyceric acid, glyceraldehydes, and tartronic acid is challenging both from the viewpoint of academic research and industrial application. Herein, we review the recent progresses in the selective oxidation of glycerol under base-free conditions. Those catalysts widely reported for the selective oxidation of the terminal hydroxyl and secondary hydroxyl groups in glycerol, such as monometallic Au, Pt, and Pd NPs, and bimetallic Au-Pt, Au-Pd, Pt-Bi, Pt-Sb, and Pt-Cu, were compared and discussed in detail. The reaction mechanism over Pt-based catalysts, possible catalyst deactivation, and the corresponding improvements are presented. Further, the recent progresses in the continuous oxidation of glycerol in fixed bed reactors and its excellent selectivity in the formation of dihydroxyacetone are highlighted. 展开更多
关键词 GLYCEROL Oxidation Base-free condition Catalyst Reaction mechanism
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Biochar can Increase Chinese Cabbage(Brassica oleracea L.)Yield,Decrease Nitrogen and Phosphorus Leaching Losses in Intensive Vegetable Soil 被引量:6
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作者 Haijun Sun Paramsothy Jeyakumar +5 位作者 Hongdong Xiao xuewen li Jiayou liu Min Yu Prabal Bir Jung Rana Weiming Shi 《Phyton-International Journal of Experimental Botany》 SCIE 2022年第1期197-206,共10页
There are few evidences on the effect of biochar on vegetable yield,nitrogen(N)and phosphorus(P)leaching losses under intensive vegetable production soil.The current field plot scale study evaluated responses of Chine... There are few evidences on the effect of biochar on vegetable yield,nitrogen(N)and phosphorus(P)leaching losses under intensive vegetable production soil.The current field plot scale study evaluated responses of Chinese cabbage(Brassica oleracea L.)yield,N and P leaching losses using five N treatments of common N application rate according to local farmers’practice(N100%),reducing 20%or 40%N fertilizer(N80%and N60%),and reducing 40%N fertilizer but incorporating 10 or 20 t/ha biochar(N60%+BC10 and N60%+BC20).Results showed that N80%and N60%decreased both the cabbage economic and leaf yields by 6.8%-36.3%and 27.4%-37.7%,respectively.Incorporation of biochar with reduced N fertilizer rates improved the cabbage yield,in particular the N60%+BC20 matched the yield that observed in N100%treatment.Enhanced N and P uptake capacities of cabbage shoot probably contributed the higher vegetable production under both biochar amendment schemes.Biochar application mitigated the NH_(4)^(+)-N and total P leaching losses by 20%-30%and 29%-32%,respectively,compared with their counterpart treatment N60%.Nevertheless,biochar exerted no influence on the NO_(3)^(-)-N leaching.In addition,soil organic matter content was recorded with 7.4%-28.7%higher following 10-20 t/ha biochar application.In conclusion,biochar application can increase economic yield of cabbage via increasing N and P use efficiency,decrease N and P leaching losses,and improve soil quality in an intensive vegetable production system. 展开更多
关键词 BIOCHAR LEACHATE non-point source pollution vegetable yield soil quality
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Metal organic polymers with dual catalytic sites for oxygen reduction and oxygen evolution reactions 被引量:4
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作者 Sijia liu Minghao liu +4 位作者 xuewen li Shuai Yang Qiyang Miao Qing Xu Gaofeng Zeng 《Carbon Energy》 SCIE CSCD 2023年第5期127-137,共11页
Metal-organic frameworks and covalent organic frameworks have been widely employed in electrochemical catalysis owing to their designable skeletons,controllable porosities,and well-defined catalytic centers.However,th... Metal-organic frameworks and covalent organic frameworks have been widely employed in electrochemical catalysis owing to their designable skeletons,controllable porosities,and well-defined catalytic centers.However,the poor chemical stability and low electron conductivity limited their activity,and single-functional sites in these frameworks hindered them to show multifunctional roles in catalytic systems.Herein,we have constructed novel metal organic polymers(Co-HAT-CN and Ni-HAT-CN)with dual catalytic centers(metal-N_(4) and metal-N_(2))to catalyze oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).By using different metal centers,the catalytic activity and selectivity were well-tuned.Among them,Co-HAT-CN catalyzed the ORR in a 4e^(-)pathway,with a half-wave potential of 0.8 V versus RHE,while the Ni-HAT-CN catalyze ORR in a 2e^(-)pathway with H_(2)O_(2) selectivity over 90%.Moreover,the Co-HAT-CN delivered an overpotential of 350 mV at 10 mA cm^(-2) with a corresponding Tafel slope of 24 mV dec^(-1) for OER in a 1.0 M KOH aqueous solution.The experimental results revealed that the activities toward ORR were due to the M-N_(4) sites in the frameworks,and both M-N_(4) and M-N_(2) sites contributed to the OER.This work gives us a new platform to construct bifunctional catalysts. 展开更多
关键词 covalent organic frameworks metal organic polymers oxygen evolution reaction oxygen reduction reaction single atom catalysts
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Oxidation resistance of powder metallurgy Ti-45Al-10Nb alloy at high temperature 被引量:3
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作者 Xuchen Jin Peihao Ye +4 位作者 Hongrui Ji Zhuanxia Suo Boxin Wei xuewen li Wenbin Fang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第12期2232-2240,共9页
TiAl alloy with high Nb content,nominally Ti-45Al-10Nb,was prepared by powder metallurgy,and the oxidation resistance at 850,900,and 950℃was investigated.The high-temperature oxidation-resistance mechanism and oxidat... TiAl alloy with high Nb content,nominally Ti-45Al-10Nb,was prepared by powder metallurgy,and the oxidation resistance at 850,900,and 950℃was investigated.The high-temperature oxidation-resistance mechanism and oxidation dynamics were discussed following the oxide skin morphology and microstructural evolution analysis.The oxide skin structures were similar for 850 and 900℃,with TiO_(2)+Al_(2)O_(3)mixture covering TiO_(2)with dispersed Nb_(2)O_(5).At 950℃,the oxide skin was divided into four sublayers,from the outside to the parent metal:loose TiO_(2)+Al_(2)O_(3),dense Al_(2)O_(3),dense TiO_(2)+Nb_(2)O_(5),and TiO_(2)matrix with dispersed Nb_(2)O_(5).The Nb layer suppressed the outward diffusion of Ti atoms,hindering the growth of TiO_(2),and simultaneously promote the formation of a continuous Al_(2)O_(3)protective layer,providing the alloy with long-term high-temperature oxidation resistance. 展开更多
关键词 Ti-45Al-10Nb elemental powder metallurgy MICROSTRUCTURE high-temperature oxidation resistance
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Effect of processing parameters on the microstructure and mechanical properties of TiAl/Ti_(2)AlNb laminated composites 被引量:1
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作者 Donghai li Binbin Wang +8 位作者 liangshun Luo xuewen li Yanjin Xu BinQiang li Diween Hawezy liang Wang Yanqing Su Jingjie Guo Hengzhi Fu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第14期228-244,共17页
In order to improve the intrinsic brittleness of TiAl alloys,Ti_(2)AlNb alloys with outstanding ductility and toughness at room temperature,and good high-temperature performance are competitive candidates in construct... In order to improve the intrinsic brittleness of TiAl alloys,Ti_(2)AlNb alloys with outstanding ductility and toughness at room temperature,and good high-temperature performance are competitive candidates in constructing the TiAl-based laminated composites.In this work,TiAl/Ti_(2)AlNb laminated composites are successfully synthesized by vacuum hot pressing combined with the foil-foil(sheet)metallurgy.Under the pressure of 65 MPa,different holding time and temperature of hot pressing are tried and the optimized fabrication parameter is acquired as 1050℃/120 min/65 MPa.Along with the changes of processing parameters,the defect,microstructure,interface,phase transformation and the corresponding mechanical properties are detailly discussed.The results show that the TiAl/Ti_(2)AlNb laminated composite fabricated at 1050℃ for 2 h achieves a good metallurgical interface bonding.The corresponding interface microstructure is composed of region I and region II.The region I consists of O,α_(2)and B2/βphase,and region II is made up ofα2.Subsequently,the tensile tests indicate that the composite synthesized at 1050℃ for 2 h possesses a maximum strength of 812 MPa and a total elongation of 1.31%at room temperature,and a strength of 539.71 MPa and the highest total elongation of 10.34%at 750℃.The well synergistic deformation ability between the interface and the two base alloys endows the composite an excellent tensile performance.Moreover,the composite processed at 1050℃ for 2 h behaves the best fracture toughness in both arrester orientation and divider orientation with the value of 32.6 MPa.m^(1/2)and 30.1 MPa.m^(1/2),respectively.The Ti_(2)AlNb alloy in the laminated structure effectively release the stress around the crack tip and plays a role in toughening.Further,crack deflection,crack bridging,crack blunting and fragmentation also make contributions to enhance the fracture toughness of the laminated composites. 展开更多
关键词 TiAl/Ti_(2)AlNb laminated composite Hot pressing Processing parameters MICROSTRUCTURE Mechanical properties FRACTURE
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Coupled study on in-situ synchrotron high-energy X-ray diffraction and in-situ EBSD on the interfacial stress gradient in layered metals
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作者 Kesong Miao Yiping Xia +7 位作者 Rengeng li Emad Maawad Weimin Gan xuewen li Hao Wu Chenglu liu Qing liu Guohua Fan 《Journal of Materials Science & Technology》 CSCD 2024年第32期184-196,共13页
As one of the heterostructures,the layered structure has attracted extensive research interest as it achieves superior properties to individual components.The layer interface is considered a critical fac-tor in determ... As one of the heterostructures,the layered structure has attracted extensive research interest as it achieves superior properties to individual components.The layer interface is considered a critical fac-tor in determining the mechanical properties of layered metals,where heterogeneity across the interface results in the strengthening of the soft layer and forming an interfacial stress gradient in the hard layer.However,there is still limited research associated with the formation of interfacial stress gradients in the hard layer,as stress measurement at high spatial resolution remains technically challenging.In the present study,we experimentally quantified the formation of interfacial stress gradients in the Ti layer of Ti/Al layered metal upon tension using in-situ high-energy X-ray diffraction(XRD).The analysis cou-pling in-situ high-energy XRD and in-situ electron back-scattered diffraction(EBSD)suggested that the interfacial stress gradient in the Ti layer rapidly rose as the Al layer was insufficient to accommodate the deformation of Ti.During the later deformation stage,collective effects of dislocation motion and geometrically necessary dislocation(GND)accumulation in the Al layer determined the evolution of in-terfacial stress gradients.The maximum interfacial stress gradient is below 0.4 MPa/μm in Ti layers,with a constant range width of 35μm independent of the macroscopic strain.The present study therefore opens a new window to local stress modification using incompatible component deformation,which is instructive for the design and fabrication of high-performance layered metals. 展开更多
关键词 Layered metals Interfacial stress gradient High-energy x-ray diffraction Mechanical property Plastic deformation
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Single active-site catalysts constructed with nonpolar-bond linked covalent organic frameworks for oxygen reduction reaction
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作者 Fancheng Meng xuewen li +6 位作者 Qizheng An Shuai Yang Zixing Zhang Qing Xu Bai Xue Xin Jin Fan Zhang 《Science China Materials》 2025年第4期1138-1144,共7页
Covalent organic frameworks(COFs)with polar linkages have been employed as metal-free catalysts for the oxygen reduction reaction(ORR).However,it is still a big challenge to precisely design or locate the catalytic si... Covalent organic frameworks(COFs)with polar linkages have been employed as metal-free catalysts for the oxygen reduction reaction(ORR).However,it is still a big challenge to precisely design or locate the catalytic sites for such kinds of COFs because their polar linkages always make some catalytic activity.In addition,the polar linkages are facile to bind with O_(2) and oxygen-contained intermediates in the catalytic process,severely weakening the long-term stability of these COFs.In this work,we demonstrated the single metalfree catalytic sites based on the pyridine-cored COFs with nonpolar linkages(C=C bonds)to catalyze the ORR.The nonpolar linkages excluded their potential roles as catalytic sites and also circumvented the possible decomposition in the process of catalysis.By modulating the pyridine N with positive charges,the catalytic performance can be previously improved,because of the enhanced Lewis acidity of the carbon atoms next to the pyridine N,and thus favorable for the electrons transfer to the catalytic sites.The newly-synthesized charged COF showed high activity of a half-wave potential of 0.74 V with a mass activity of 4.34 A g^(-1),which was 50 mV more positive and 1.63 times higher than those of the neutral COF.And the nonpolar linkages made the COFs display better long-term stability than other metal-free COFs.The theoretical calculation revealed that the ionization of pyridine promoted the formation of the intermediate OOH*,and thus improved the catalytic activity.This work gives us a new insight into designing single sites based on COFs. 展开更多
关键词 covalent organic frameworks charging-tuned nonpolar linkage Lewis acidity oxygen reduction reaction
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Suppressing the donor-like effect via fast extrusion engineering for high thermoelectric performance of polycrystalline Bi_(2)Te_(2.79)Se_(0.21) 被引量:2
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作者 Xusheng liu Tong Xing +5 位作者 Pengfei Qiu Tingting Deng Peng li xuewen li Xiaoya li Xun Shi 《Journal of Materiomics》 SCIE CSCD 2023年第2期345-352,共8页
Bi2Te3-based alloys are the most mature commercial thermoelectric(TE)materials for the cooling application near room temperature.However,the poor mechanical properties of the commercial zone melting(ZM)ingot severely ... Bi2Te3-based alloys are the most mature commercial thermoelectric(TE)materials for the cooling application near room temperature.However,the poor mechanical properties of the commercial zone melting(ZM)ingot severely limits the further application.Meanwhile,due to the donor-like effect,the robust polycrystalline n-type bulks usually have low TE performance near room temperature.Herein,based on the commercial ZM ingots,a high figure of merit(zT)of 1.0 at 320 K and good mechanical properties are achieved via the hot extrusion.The dynamic recrystallization in the hot-extrusion process can suppress the donor-like effect and refine the large ZM grains into fine-equiaxed grains.Moreover,the obtained polycrystalline Bi2Te2.79Se0.21 has good preferential orientation and high carrier mobility(m).The high m and the weaken donor-like effect maintain the high power factor(PF)of 43.1 mW cm^(-1)K^(-2)in the hot-extruded ZM sample.Due to the enhanced phonon scattering,the total thermal conductivity ktot decreased to 1.35 W·m^(-1)·K^(-1).To demonstrate the good mechanical properties of the extruded ZM sample,micro TE dices with the cross sections of 300μm×300 mm and 200μm×200 mm are successfully cut from the extrusion sample.This study provided a fast and low-cost extrusion technique to improve the TE and mechanical properties of the commercial ZM ingot at room temperature. 展开更多
关键词 THERMOELECTRIC Bismuth telluride Donor-like effect Hot extrusion
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The expanded development and application of CRISPR system for sensitive nucleotide detection 被引量:2
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作者 Fengjing Jia xuewen li +1 位作者 Chao Zhang Xueming Tang 《Protein & Cell》 SCIE CAS CSCD 2020年第9期624-629,共6页
CRISPR/Cas system,originally developed as genetic editing tool,also shows great potentials for nucleotide detection.A recent study published in Molecular Cell(Freije et al.,2019)developed a Cas13a-based CARVER(Cas13-a... CRISPR/Cas system,originally developed as genetic editing tool,also shows great potentials for nucleotide detection.A recent study published in Molecular Cell(Freije et al.,2019)developed a Cas13a-based CARVER(Cas13-assisted restriction of viral expression and readout)to detect RNA viruses such as lymphocytic choriomeningitis,influenza A and vesicular stomatitis,which provided a potential expanded application for the detection of a broad range of viral nucleotides in disease diagnosis. 展开更多
关键词 CRISPR/Cas expanded APPLICATION
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Boosting hydrogen peroxide production via establishment and reconstruction of single-metal sites in covalent organic frameworks 被引量:2
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作者 Shuai Yang Lanlu Lu +9 位作者 Ji li Qingqing Cheng Bingbao Mei xuewen li Jianing Mao Panzhe Qiao Fanfei Sun Jingyuan Ma Qing Xu Zheng Jiang 《SusMat》 2023年第3期379-389,共11页
Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hinderin... Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hindering an in-depth understanding of the catalytic mechanism.In this work,uniform Pt-N_(1)O_(1)Cl_(4)sites chelated via C-N and C=O bonds along the one-dimensional and open channels of TP-TTA-COF were established.Different from conventional single-metal sites constructed for the near-free platinum for hydrogen evolution,the as-constructed PtCl-COF showed 2e−oxygen reduction for H_(2)O_(2)production.We tracked the dynamic evolution process of atomic Pt sites in which Pt-N_(1)O_(1)Cl_(4)was transformed into Pt-N_(1)O_(1)(OH)_(2)using in situ X-ray adsorption.The theoretical calculations revealed that the strong Pt-support interaction in Pt-N_(1)O_(1)(OH)_(2)facilitated*OOH formation and thus led to higher selectivity and activity for the oxygen reduction reaction in the 2e−pathway.This work can expand the applications of COFs through the regulation of their local electronic states for the manipulation of the metal center. 展开更多
关键词 covalent organic framework oxygen reduction reaction single-atom catalysis
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Laboratory and Semi-Field Evaluation on S-Methoprene Formulations Against Anopheles sinensis(Diptera:Culicidae)—Yuxi City,Yunnan Province,China 被引量:1
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作者 Wenbo Hu Yijin Chen +4 位作者 Ying liang Tianyun Su Qiyong liu xuewen li Xiaobo liu 《China CDC weekly》 SCIE CSCD 2024年第6期105-108,共4页
Summary What is already known about this topic?Anopheles sinensis(An.sinensis)is the predominant malaria vector in China.The impact of S-methoprene on the emergence process of mosquito larvae suggests its potential as... Summary What is already known about this topic?Anopheles sinensis(An.sinensis)is the predominant malaria vector in China.The impact of S-methoprene on the emergence process of mosquito larvae suggests its potential as a control method for vector mosquitoes.However,the efficacy of S-methoprene in controlling An.sinensis has not yet been demonstrated.What is added by this report? 展开更多
关键词 SINENSIS China. predominant
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耕地非农化严格管控下的地方合作、共谋与制度创新——源自浙江省土地发展权折抵指标交易政策的证据 被引量:16
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作者 李学文 张蔚文 陈帅 《经济学(季刊)》 CSSCI 北大核心 2020年第3期797-824,共28页
在中国式央地分权结构下,地方政府具有相当的自由裁量权,从而基于地方利益选择相互竞争还是合作,甚至竞次或者共谋。本文以地方政府为获取超额建设占用耕地指标而创立的土地发展权折抵交易政策为例,提出了经济层面地方合作乃至共谋可能... 在中国式央地分权结构下,地方政府具有相当的自由裁量权,从而基于地方利益选择相互竞争还是合作,甚至竞次或者共谋。本文以地方政府为获取超额建设占用耕地指标而创立的土地发展权折抵交易政策为例,提出了经济层面地方合作乃至共谋可能性的假说,并借助1999—2008年间浙江省的土地折抵指标交易数据进行实证检验。结果发现,经济发展水平差距、资源禀赋差距和人缘网络关系显著影响地方政府间通过交易共谋超额建设占用耕地指标的概率。本文的研究为解释中国式分权化改革后地方政府行为的逻辑提供了新的视角和实证依据。 展开更多
关键词 地方政府 制度创新 土地发展权交易
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Prmt5 is essential for intestinal stem cell maintenance and homeostasis
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作者 li Yang xuewen li +1 位作者 Chenyi Shi Bing Zhao 《Cell Regeneration》 2025年第2期21-34,共14页
Intestinal homeostasis relies on the continuous renewal of intestinal stem cells(ISCs),which could be epigenetically regulated.While protein arginine methyltransferase 5(Prmt5)is known to play a key role in multiple o... Intestinal homeostasis relies on the continuous renewal of intestinal stem cells(ISCs),which could be epigenetically regulated.While protein arginine methyltransferase 5(Prmt5)is known to play a key role in multiple organs as an epigenetic modifer,its specifc function in maintaining intestinal homeostasis remains to be elucidated.Here,we show that Prmt5 is highly expressed in mouse crypts.The deletion of Prmt5 results in ISCs defciency,ectopic localization of Paneth cells,and spontaneous colitis.Mechanistically,Prmt5 sustains a high level of H3K27ac accumulation by inhibiting Hdac9 expression in the intestinal epithelium,and maintains the stemness of ISCs in a cell-autonomous manner.Notably,inhibition of histone deacetylases can rescue both self-renewal and diferentiation capacities of Prmt5-depleted ISCs.These fndings highlight Prmt5 as a critical regulator in intestinal epithelium development and tissue homeostasis. 展开更多
关键词 Prmt5 Intestinal stem cells HOMEOSTASIS H3K27ac
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