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Microstructure and texture evolution of Cu–Cr–Co–Ti alloys during the two-stage cryorolling

Rare Metals 2024年第9期43卷 4535-4547页

作者： Jia-Jun Zhang long-jian li Zhi-Feng liu Zong-Ning Chen En-Yu Guo Hui-Jun Kang Ren-Geng li Tong-Min Wang Key Laboratory of Solidification Control and Digital Preparation Technology (liaoning Province) School of Materials Science and EngineeringDalian University of Technology Center of Hyper-Gravity Experimental and Interdisciplinary Research Zhejiang University Ningbo Institute of Dalian University of Technology！Ningbo315000 China Key Laboratory for light-Weight Materials Nanjing Tech University

This study entailed an investigation of the mechanical properties, microstructural and texture orientation evolutions of CuDCrDCoDTi alloys prepared via twostage cryorolling and intermediate aging treatment. To this end, X-ray diffraction and electron backscatter diffraction were employed. The results indicate that the two-stage cryorolling and intermediate aging treatments led to the development of profuse twin bundles and significantly enhanced the mechanical properties. The initial cryorolling led to coplanar slip and developed a strong Y({111} ) orientation, accelerating the formation of Goss({011} ) orientation and a Brass-type *** intermediate aging treatment relieved the restriction on dislocation slip and reoriented the grains toward the Copper({112} ) and Z({111} ) *** Z orientation, with a relatively high volume fraction,dominated the macrotexture. Secondary cryorolling intensified twinning and shear banding, transforming the Copper-type shear bands into Brass-type shear bands with rhomboidal prism morphology. The areas inside the Brasstype shear bands exhibited a Y orientation, and the areas outside the shear bands exhibited a stable Brass-type texture. The evident decrease in the weighted Schmid factors demonstrated that the two-stage cryorolling and intermediate aging treatment can modify the texture evolution and aid the design of high-performance Cu alloys.

关键词： Copper alloys Electron backscatter diffraction Macrotexture evolution Schmid factor Two-stage cryorolling

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Generation of a curved plasma channel from a discharged capillary for intense laser guiding

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High Power Laser Science and Engineering 2023年第5期11卷 85-92页

作者： jian-long li Bo-Yuan li Xin-Zhe Zhu Ze-Wu Bi Xin-Hui Wen lin Lu Xiao-Hui Yuan Feng liu Min Chen Key Laboratory for Laser Plasmas(Ministry of Education) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiao Tong UniversityShanghaiChina

Straight plasma channels are widely used to guide relativistic intense laser pulses over several Rayleigh lengths for laser wakefield ***,a curved plasma channel with gradually varied curvature was suggested to guide a fresh intense laser pulse and merge it into a straight channel for staged wakefield acceleration[***.120,154801(2018)].In this work,we report the generation of such a curved plasma channel from a discharged *** longitudinal and transverse density distributions of the plasma inside the channel were diagnosed by analyzing the discharging *** of the gas-filling mode,back pressure and discharging voltage on the plasma density distribution inside the specially designed capillary are *** show that a longitudinally uniform and transversely parabolic plasma channel with a maximum channel depth of 47.5µm and length of 3 cm can be produced,which is temporally stable enough for laser *** such a plasma channel,a laser pulse with duration of 30 fs has been successfully guided along the channel with the propagation direction bent by 10.4◦.

关键词： curved plasma channel discharging spectroscopy laser guiding

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Ni-Catalyzed Enantioselective Difunctionalization of Alkynes to Azepine Derivatives Bearing a Quaternary Center and an Unprotected Imine

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Chinese Journal of Chemistry 2024年第8期42卷 873-878页

作者： jian long Zhiwu Lu Xiao-lin li Peng Xue Wen-Bo liu Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)and College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Comprehensive Summary,The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)-catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.

关键词： Nickel Asymmetric catalysis N-Heterocycles Alkyne functionalization Quaternary centers

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Generalized Inverses and Units in a Unitary Ring

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1000-1014页

作者： Yu Kun ZHOU jian long CHEN School of Mathematics Southeast UniversityNanjing 210096P.R.China

Let R be a unitary ring and a,b∈R with ab=*** find the 2/3 property of Drazin invertibility:if any two of a,b and a+b are Drazin invertible,then so is the third ***,we combine the 2/3 property of Drazin invertibility to characterize the existence of generalized inverses by means of *** applications,the need for two invertible morphisms used by You and Chen to characterize the group invertibility of a sum of morphisms is reduced to that for one invertible morphism,and the existence and expression of the inverse along a product of two regular elements are obtained,which generalizes the main result of Mary and Patricio(2016)about the group inverse of a product.

关键词： Leftπ-regular element stronglyπ-regular element group inverse Drazin inverse inverse along an element

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On entire solutions of some Fermat type differential-difference equations

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 69-88页

作者： long jian-ren QIN Da-zhuan School of Mathematical Sciences Guizhou Normal UniversityGuiyang 550025China

On one hand,we study the existence of transcendental entire solutions with finite order of the Fermat type difference *** the other hand,we also investigate the existence and growth of solutions of nonlinear different... 详细信息

关键词： entire solutions differential-difference equations existence finite order

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Fabrication of a novel electrochemical sensor based on MnFe_(2)O_(4)/graphene modified glassy carbon electrode for the sensitive detection of bisphenol A

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Journal of Central South University 2024年第6期31卷 1856-1869页

作者： GAO Si-lei TANG jian-she XIANG li long Jin-wei Department of Environmental and Energy Engineering Anhui Jianzhu UniversityHefei 230601China Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse Hefei 230601China

Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal ***,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal *** morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high *** addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.

关键词： MnFe_(2)O_(4) graphene electrochemical sensor bisphenol A

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A novel and promising engineering application of carbon dots:Enhancing the chloride binding performance of cement

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Chinese Chemical Letters 2024年第6期35卷 409-416页

作者： Wu-jian long Yang Yu Chuang He Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering Key Lab of Coastal Urban Resilient InfrastructureMOECollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Corrosion of reinforcement induced by chloride invasion is extensively considered as the dominating deterioration mechanism of reinforced concrete(RC)structures,leading to serious safety hazards and tremendous economic ***,it still lacks well dispersive and cost-efficient nanomaterials to improve the anti-chloride-corrosion ability of RC ***,specific carbon dots(CDs)with high dispersity and low cost are deliberately designed,successfully prepared by hydrothermal processing,and then firstly applied to immensely enhance chloride binding performance of cement,thereby contributing to suppressing the corrosion of ***,the tailored CDs are composed of the carbon core with highly crystalline sp^(2)C structures and oxygen-containing groups connecting on the carbon core;The typical equilibrium test confirms that with respect to that of the blank cement paste,the chloride binding capacity of cement paste involving 0.2 wt%(by weight of cement)CDs is increased by 109% after 14-day exposure to 3 mol/L Na Cl solution;according to comprehensive analyses of phase compositions,the chloride binding mechanism of CDs-modified cement is rationally attributed to the fact that the incorporation of CDs advances the formation of calcium silicate hydrate(C-S-H)gels and Friedel's salt(Fs),thus enormously enhancing the physically adsorbed and chemically bound chloride ions of cement *** work not only firstly provides a novel high-dispersity and low-cost nanomaterial toward the durability enhancement of RC structures,but also broadens the application of CDs in the field of engineering,conducing to stimulating their industrialization development.

关键词： Carbon dots Chloride binding Cement Chloride binding mechanism Friedel’s salt

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C-reactive protein decreases interleukin-8 production in human endothelial progenitor cells by inhibition of p38 MAPK pathway

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Chinese Medical Journal 2009年第16期122卷 1922-1928页

作者： NAN Jing-long li jian-jun HE jian-guo Department of Cardiology Fu Wai Hospital Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100037 China

Background C-reactive protein （CRP） has been reported to damage the vascular wall by inducing endothelial dysfunction and inflammation, and it is also speculated to have a role in attenuating angiogenic functions of human endothelial progenitor cells （EPCs）. Interleukin-8 （IL-8） is an important mediator of the paracrine mitogenic effect of EPCs which has direct angiogenic effects on mature endothelial cells. We, herein, investigated the direct effect of CRP on IL-8 production and gene expression in cultured human EPCs. Methods EPCs were isolated from the peripheral venous blood of healthy male volunteers. Cells were cultured in EndoCultTM liquid medium in the absence and presence of CRP at clinically relevant concentrations （5 to 25 μg/ml） for different durations （3 to 48 hours）. IL-8 protein and mRNA of cultured EPCs were evaluated using EliSA and real-time PCR. Results The results showed that CRP at a concentration of 10 μg/ml significantly reduced IL-8 secretion of cultured EPCs with a peak at 25 μg/ml, and also decreased mRNA expression in EPCs with a peak at 12 hours. In addition, preincubation of EPCs with SB203580, an inhibitor of p38 mitogen-activated protein kinase （MAPK） decreased CRP inhibition of IL-8 mRNA expression at 12 hours in EPCs. Conclusions Our study, for the first time, demonstrates that CRP directly inhibits EPCs IL-8 secretion, a key cytokine player of angiogenesis induced by EPCs. Inhibition occurred in part via an effect of CRP to active the p38 MAPK signal transduction pathway in EPC. The ability of CRP to inhibit EPCs IL-8 secretion may represent an important mechanism that further links inflammation to cardiovascular disease.

关键词： C-reactive protein endothelial progenitor cells interleukin-8

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In situ regulating intimately connected heterostructure by decomposition of solid solution oxides toward high-efficient water oxidation

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Rare Metals 2024年第4期43卷 1557-1569页

作者： Shao-Fei Zhang Xiao-Lu Yin Jin Wang jian-li Kang Tian-Tian li Jin-Feng Sun Yong-Qiang Meng jian-jiang Wang Dian-long Wang Kai-Qiang Qin Hebei Key Laboratory of Flexible Functional Materials/Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018China Key Laboratory of Advanced Ceramics and Machining Technology/Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Electrochemical Engine Center Department of Mechanical EngineeringPennsylvania State UniversityUniversity ParkPA16802USA

Heterogeneous interfaces produced by interdomain interactions on a nanoscale performs a crucial role in boosting the properties of an electrocatalyst toward oxygen evolution reaction(OER)***,a series of dual-phase electrodes with intimately connected heterointerfaces are prepared by in situ decomposing solid solution oxide of Ni_(x)Co_(y)Fe_(100-x-y)O,which grew on Ni foam massively via an ultrafast combustion ***,with high-reaction kinetics caused by the reduction treatment at 450℃,the less electronegative Fe and Co are more oxyphilic than Ni,which facilitated their co-exsolution and formation of CoFe_2O_4/NiO oxide with enriched oxygen *** from the nanoporous framework,heterojunction structure,and oxygen defects,the self-supporting electrodes present rapid charge/mass transmission and provide abundant active sites for *** optimized sample(R-SNCF4.5)shows low overpotentials of 226 and 324 mV at 10 and100 mA·cm^(-2),a small Tafel slope(46.7 mV·dec^(-1)),and excellent *** assembled R-SNCF4.5//Pt/C/NF electrolyzer demonstrates continuous electrolysis over 50 h at a current density of 10 mA·cm^(-2),under 1.51 *** functional theory(DFT)calculations verify that the strong electronic modulation plays a critical part in the CoFe_2O_4/NiO hybrid by lowering the energy barriers for the ratedetermining steps,and Fe sites are the most active OER sites.

关键词： Rapid combustion Decomposition of solid solution oxide Dual-phase heterostructure Oxygen evolution reaction Theoretical calculation

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Development in oxide metallurgy for improving the weldability of high -strength low-alloy steel-Combined deoxidizers and microalloying elements

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1263-1284页

作者： Tingting li jian Yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The mechanisms of oxide metallurgy include inducing the formation of intragranular acicular ferrite(IAF)using micron-sized inclusions and restricting the growth of prior austenite grains(PAGs)by nanosized particles during *** chaotically oriented IAF and refined PAGs inhibit crack initiation and propagation in the steel,resulting in high impact *** work summarizes the com-bined effect of deoxidizers and alloying elements,with the aim to provide a new perspective for the research and practice related to im-proving the impact toughness of the heat affected zone(HAZ)during the high heat input *** complex deoxidation with other strong deoxidants,such as Mg,Ca,Zr,and rare earth metals(REMs),can improve the toughness of the heat-affected zone(HAZ)by re-fining PAGs or increasing IAF ***,it is difficult to identify the specific phase responsible for IAF nucleation because ef-fective inclusions formed by complex deoxidation are usually *** alloying elements,such as C,Si,Al,Nb,or Cr,con-tents can impair HAZ toughness.A high C content typically increases the number of coarse carbides and decreases the potency of IAF ***,Cr,or Al addition leads to the formation of undesirable *** reduces the high-temperature stability of the ***,V,and B can enhance HAZ ***-containing precipitates present good thermal *** or V(C,N)is ef-fective in promoting IAF nucleation due to its good coherent crystallographic relationship with *** formation of the B-depleted zone around the inclusion promotes IAF *** interactions between alloying elements are complex,and the effect of adding dif-ferent alloying elements remains to be *** the future,the interactions between various alloying elements and their effects on ox-ide metallurgy,as well as the calculation of the nucleation effects of effective inclusions using first principles calculations will become the focus of

关键词： oxide metallurgy technology heat affected zone high-strength low-alloy steel intragranular acicular ferrite microalloying element

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