检索结果-南通市图书馆

Journal of Integrative Plant Biology 2010年第3期52卷 315-323页

作者： hai-yan liu jin-ran dai dong-ru feng bing liu hong-bin wang jin-fa wang The State Key Laboratory of Biocontrol and The Key Laborat-ory of Gene Engineering of Ministry of Education School of Life Sciences Sun Yat-sen University Guangzhou 510275 China

Asr （abscisic acid, stress, ripening induced） genes are typically upregulated by a wide range of factors, including drought, cold, salt, abscisic acid （ABA） and injury; in addition to plant responses to developmental and environmental signals. We isolated an Asr gene, MpAsr, from a suppression subtractive hybridization （SSH） cDNA library of cold induced plantain （Musa paradisiaca） leaves. MpAsr expression was upregulated in Fusarium oxysporum f. sp. cubense infected plantain leaves, peels and roots, suggesting that MpAsr plays a role in plantain pathogen response. In addition, a 581-bp putative promoter region of MpAsr was isolated via genome walking and cis-elements involved in abioUc stress and pathogen-related responses were detected in this same region. Furthermore, the MpAsr promoter demonstrated positive activity and inducibility in tobacco under F. oxysporum f. sp. cubense infection and ABA, cold, dehydration and high salt concentration treatments. Interestingly, transgenic Arabidopsis plants overexpressing MpAsr exhibited higher drought tolerance, but showed no significant decreased sensitivity to F. oxysporum f. sp. cubense. These results suggest that MpAsr might be involved in plant responses to both abiotic stress and pathogen attack.

关键词： ABSCISIC acid AQUIFER storage recovery FUSARIUM oxysporum GENE expression TOBACCO PATHOGENIC microorganisms

Effect of heat treatment on corrosion behaviors of Mg-6Gd-3Y-0.5Zr alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第5期21卷 599-612页

作者： Fei wang bin-guo Fu Yu-feng wang Tian-shun dong Guo-lu Li jin-hai liu Hebei Key Laboratory of New Functional Materials School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin 300301China Tianjin Aerospace Long March Technology and Equipment Co. Ltd.Tianjin 300462China

The microstructures and corrosion behaviors of as-cast,T4-treated,and T6-treated Mg-6Gd-3Y-0.5Zr alloys were systematically investigated by SEM,TEM,immersion test,and electrochemical corrosion *** results show that the microstructure of the as-cast alloy is composed ofα-Mg and Mg_(24)(Gd,Y)_(5)eutectic phase,and in T4-treated alloy,Mg_(24)(Gd,Y)_(5)phase dissolves into theα-Mg matrix,leading to an increase in the(Y,Gd)H_(2)*** T6 treatment,nanoscale Mg_(24)(Gd,Y)_(5)phase dispersedly precipitates from theα-Mg matrix,and exhibits a specific orientation relationship with theα-Mg:(332)Mg_((24)(Gd,Y)_(5))//(1011)_(α-Mg),[136]Mg_((24)(Gd,Y)_(5))//[1210]_(α-Mg).The corrosion resistance of the Mg-6Gd-3Y-0.5Zr alloys can be ranked in the following order:T6-treated alloy exhibits the highest corrosion resistance,followed by the T4-treated alloy,and finally,the as-cast *** corrosion products of the alloys are all composed of MgO,Mg(OH)_(2),Gd_(2)O_(3),Y_(2)O_(3),and MgCl_(2).The corrosion behavior of Mg-6Gd-3Y-0.5Zr alloy is closely related to the precipitated *** establishing the relationship between corrosion rate,hydrogen evolution rate,and corrosion potential,it is further demonstrated that during the micro galvanic corrosion process,the coarse Mg_(24)(Gd,Y)_(5)phase in the as-cast alloy undergoes extensive dissolution,and(Y,Gd)H_(2)phase promotes the dissolution of theα-Mg matrix in the T4-treated alloy,intensifying the hydrogen evolution *** T6-treated alloy,with dispersive precipitation of nanoscale Mg_(24)(Gd,Y)_(5)phase,exhibits better corrosion resistance performance.

关键词： Mg-6Gd-3Y-0.5Zr alloy heat treatment microstructure precipitated phase corrosion resistance

Investigating the Absorption and Desorption Behavior of Methylene Chloride in the Poly(aryl ether ketone) Film with Different Crystallinities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 239-246,I0009页

作者： hong-ru yang jin-dong Zhang dong-Ting Gao Gang liu Chun-hai Chen Jia-Nan Yao Center for Advanced Low-Dimension Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China

Poly(aryl ether keton e)(PAEK) films with different crystallinities were obtained by controlling the cooling rate,which were subjected to the absorption and desorption of methylene chloride(CH_(2)Cl_(2)).We employed attenuated total reflection Fourier transform infrared(ATR-FTIR)spectroscopy analyses to investigate the diffusion behavior of CH_(2)Cl_(2) in PAEK films with different *** to the Fickian diffusion model,the calculated diffu sion coefficients of CH_(2)Cl_(2) in PAEK films were observed to decrease with increasing *** effect of CH_(2)Cl_(2)absorption and desorption on the mechanical properties of PAEK films with different crystallinity was further analyzed using tensile *** tensile tests exhibited that CH_(2)Cl_(2) has two concurrent effects:plasticization and solvent-induced *** scanning calorimetry(DSC) and wide-angle X-ray diffraction(WXRD) techniques further confirmed solvent-induced crystallization *** results would be beneficial to understand the solvent resistance of PAEK materials and consequently provide the practical application conditions of PAEK with a theoretical basis.

关键词： Poly(aryl ether ketone) Diffusion behavior Infrared spectra Solvent-induced crystallization Mechanical properties

Gas microchannel plate-pixel detector for X-ray polarimetry

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 60-73页

作者： Huan-Bo feng hong-Bang liu dong wang Zi-Li Li Shu-Lin liu Qian liu Hang-Zhou Li bin-Long wang yan-Jun Xie Zong-wang fan Hui wang ran Chen Di-fan Yi rui-Ting Ma Fei Xie Bo Peng Xiang-Ming Sun jin Li En-Wei Liang Present Address:Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China PLAC Key Laboratory of Quark and Lepton Physics(MOE)Central China Normal UniversityWuhan 430079China School of Science Huzhou UniversityHuzhou 313000China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China School of Physical Science University of Chinese Academy of SciencesBeijing 100049China The 13th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050057China

POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related ***-2 is expected to utilize an on-board polarimeter that is sensitive to soft X-rays(2-10 keV),called low-energy polarization *** have developed a new soft X-ray polari-zation detector prototype based on gas microchannel plates(GMCPs)and pixel chips(Topmetal).The GMCPs have bulk resistance,which prevents charging-up effects and ensures gain stability during *** detector is composed of low outgassing materials and is gas-sealed using a laser welding technique,ensuring long-term stability.A modulation factor of 41.28%±0.64% is obtained for a 4.5 keV polarized X-ray beam.A residual modulation of 1.96%±0.58% at 5.9 keV is observed for the entire sensitive area.

关键词： X-ray polarimetry Gas microchannel plate-pixel detector Gamma-ray bursts

Numerical simulation of melt flow and temperature field during DC casting 2024 aluminium alloy under different casting conditions

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第4期21卷 387-396页

作者： jin-chuan wang Yu-bo Zuo Qing-feng Zhu jing Li rui wang Xu-dong liu Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Engineering Research Center of Advanced Materials Preparing Technology Ministry of EducationShenyang 110819China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Casting speed,casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting *** parameters significantly influence the flow and temperature fields during casting,which are crucial for the quality of the ingot and can determine the success or failure of the casting *** simulation,with the advantages of low cost,rapid execution,and visualized results,is an important method to study and optimize the DC casting *** the present work,a simulation model of DC casting 2024 aluminum alloy was established,and the reliability of the model was ***,the influence of casting parameters on flow field and temperature field was studied in detail by numerical simulation *** show that with the increase of casting speed,the melt flow becomes faster,the depths of slurry zone and mushy zone increase,and the variation of slurry zone depth is greater than that of mushy *** an increase in casting temperature,the melt flow rate increases,the depth of the slurry zone becomes shallower,and the depth of the mushy zone experiences only minor *** simulation results further indicate that the increase of the flow rate of the secondary cooling water slightly reduces the depths of both slurry and mushy zone.

关键词： aluminium DC casting flow field temperature field numerical simulation

Boundary Regularity of Isometries Between Infinitely Flat Complex Domains

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第6期40卷 1375-1387页

作者： jin Song liu Fei TAO hong Yu wang Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190P.R.China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049P.R.China Beijing International Center for Mathematical Research Peking UniversityBeijing 100871P.R.China School of Science Beijing University of Posts and TelecommunicationsBeijing 100876P.R.China Key Laboratory of Mathematics and Information Networks(Beijing University of Posts and Telecommunications) Ministry of EducationBeijing 100876P.R.China

In this paper we prove that isometries with respect to the Kobayashi metric between certain domains having boundary points at which the boundary is infinitely flat extend continuously to the *** strategy is to reestab... 详细信息

关键词： Boundary extension Kobayashi metric isometries

Exploration on electrical resistance tomography in characterizing the slurry spatial distribution in cemented granular materials

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第3期18卷 365-379页

作者： Bohao wang Wei wang feng jin Handong TAN Ning liu Duruo HUANG State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China Institute of Science and Technology China Three Gorges CorporationBeijing 100038China School of Geophysics and Information Technology China University of GeosciencesBeijing 100083China

This study investigated the application of electrical resistance tomography(ERT)in characterizing the slurry spatial distribution in cemented granular materials(CGMs).For CGM formed by self-flow grouting,the voids in the accumulation are only partially filled and the bond strength is often limited,which results in difficulty in obtaining in situ samples for quality ***,it is usually infeasible to evaluate the grouting effect or monitor the slurry spatial distribution by a mechanical *** this research,the process of grouting cement paste into high alumina ceramic beads(HACB)accumulation is reliably monitored with *** shows that ERT results can be used to calculate the cement paste volume in the HACB accumulation,based on calibrating the saturation exponent n in Archie’s *** results support the feasibility of ERT as an imaging tool in CGM characterization and may provide guidance for engineering applications in the future.

关键词： electrical resistance tomography cemented granular material grouting spatial distribution Archie’s law

Effect of Al_(2)O_(3)fiber on twin intersections-induced dynamic recrystallization in fine-grained TiAl matrix composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第5期172卷 1-14页

作者： Yaofeng Luo yan wang Li wang bin liu Yong liu State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Dynamic recrystallization(DRX)is of great significance for the thermomechanical processing and microstructural regulation of TiAl ***,the underlying DRX mechanism remains poorly *** this study,an Avrami kinetics model for DRX was established,which was capable of predicting the DRX fraction *** addition,the effect of Al_(2)O_(3)short fiber on the DRX mechanisms of TiAl matrix composite during the isothermal compression was investigated for the first *** re-sults showed that other than inhibiting DRX by particles in the TiAl matrix composites,the addition of Al_(2)O_(3)short fiber accelerated a novel DRX process,which was induced by twinning and twin intersec-tions(TDRX).Thus,this composite exhibited a higher DRX rate than that of the as-cast TiAl monolithic *** origin of the twin intersection and TDRX for the composite was *** stress concentration near the Al_(2)O_(3)fiber was above the critical shear stress for twinning and thus was favorable for the formation of twinning and twin *** high stored strain energy at the regions of twins and twin intersections provided the driving force for *** accelerated the grain refinement in the TiAl matrix near the Al_(2)O_(3)*** present findings would provide a new perspective on DRX mechanisms,and provide the scientific guidance for optimizing the microstructures of TiAl matrix composites.

关键词： TiAl matrix composite Al_(2)O_(3)fiber Twin intersection Dynamic recrystallization

Effects of seepage pressure on the mechanical behaviors and microstructure of sandstone

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2033-2051页

作者： Xuewei liu Juxiang Chen bin liu Sai wang Quansheng liu jin Luo State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China faculty of Engineering China University of GeosciencesWuhan430074China Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province School of Civil EngineeringWuhan UniversityWuhan430072China

Surrounding rocks of underground engineering are subjected to long-term seepage pressure,which can deteriorate the mechanical properties and cause serious *** order to understand the impact of seepage pressure on the mechanical property of sandstone,uniaxial compression tests,P-wave velocity measurements,and nuclear magnetic resonance(NMR)tests were conducted on saturated sandstone samples with varied seepage pressures(i.e.0 MPa,3 MPa,4 MPa,5 MPa,6 MPa,7 MPa).The results demonstrate that the mechanical parameters(uniaxial compressive strength,peak strain,elastic modulus,and brittleness index),total energy,elastic strain energy,as well as elastic strain energy ratio,decrease with increasing seepage pressure,while the dissipation energy and dissipation energy ratio ***,as seepage pressure increases,the micro-pores gradually transform into meso-pores and *** increases the cumulative porosity of sandstone and decreases P-wave *** numerical results indicate that as seepage pressure rises,the number of tensile cracks increases progressively,the angle range of microcracks is basically from 50-120to 80-100,and as a result,the failure mode transforms to the tensile-shear mixed failure ***,the effects of seepage pressure on mechanical properties were *** results show that decrease in the effective stress and cohesion under the action of seepage pressure could lead to deterioration of strength behaviors of sandstone.

关键词： Rock mechanics Mechanical property Seepage pressure Numerical simulation Microcracks

A Review on Particle Reinforced Mg Matrix Composites fabricated by Powder Metallurgy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 391-400页

作者： Zhiyuan liu Li jin Jian Zeng Fulin wang fenghua wang Shuai dong Jie dong National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder *** article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the *** addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are *** paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’***,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.

关键词： Magnesium matrix composites Reinforcing particle Powder metallurgy Mechanical properties Configuration