检索结果-南通市图书馆

Mechanism of high-energy pulsed current-assisted rolling of 08AL carbon steel ultra-thin strip

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 Iron and Steel Research International 2024年第2期31卷 416-427页

作者： Zhong-kai Ren Ya-nan Xu Jia-zhao Chen He Li Rui-lin Yuan zhen-hua wang Tao wang Xiao Liu College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment(Ministry of Education) Taiyuan University of TechnologyTaiyuan030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710016ShaanxiChina

To improve the plastic deformation performance of a 08AL carbon steel ultra-thin strip,a pulsed electric field was integrated into the plastic processing of the ultra-thin strip,and the effects of high-energy current on its deformation ability were ***-assisted tensile tests were employed,and the results clarified that the pulsed current could reduce the activation energy of faults and promoted dislocation slip within grains and at grain boundaries,leading to a decrease in the deformation resistance of the metal and an increase in its plastic *** the current density of 2.0 A/mm2,the yield strength,tensile strength,and elongation of the rolled sample reached 425 MPa,467 MPa,and 12.5%,*** the rolling process,it was found that the pulsed current promoted the dynamic recrystallization of the ultra-thin strip,reduced its dislocation density and deformation resistance,and promoted the coordinated deformation of the metal.

关键词： 08AL ultra-thin strip High-energy pulsed current Mechanical property Dislocation density Dynamic recrystallization

Formation of coherent BCC/B2 microstructure and mechanical properties of Al-Ti-Zr-Nb-Ta-Cr/Mo light-weight refractory high-entropy alloys

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2022年第8期41卷 2886-2893页

作者： Dong-Ming Jin zhen-hua wang Jin-Feng Li Ben Niu Qing wang Engineering Research Center of High Entropy Alloy Materials(Liaoning Province) Key Laboratory of Materials Modification by LaserIon and Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Institute of Materials China Academy of Engineering PhysicsMianyang621908China

The present work investigated the formation of coherent body-centered-cubic(BCC)/B2 microstructure in Al-Ti-Zr-Nb-Ta-Cr/Mo refractory high-entropy alloy system,in which three alloys with the composition of Al_(2)Ti_(6) Zr_(2)Nb_(3)Ta_(2)(Cr/Mo)_(1)were *** as-cast alloy ingots were homogenized at 1573 K for 2 h and then aged at different temperatures for 24 *** is found that the BCC/B2 coherent microstructure with cuboidal BCC nanoprecipitates into the B2 matrix would be formed in873 K-aged Al_(2)Ti_(6) Zr_(2)Nb_(3)Ta_(2)Cr_(0.5)Mo_(0.5)alloy with half Cr and half Mo,which is ascribed to a moderate lattice misfit(ε=0.94%)between BCC and B2 *** is due to the special coherent microstructure that results in a prominent mechanical property with the highest compressive yield strength(σ_(YS)=1314 MPa)and good plasticity among these alloys,while coarse Cr2 Ti and Zr_(5)Al_(3)particles are existed in 873 K-aged alloy with *** 1073 K aging,all these alloys with Cr_(1),Cr_(0.5)Mo_(0.5)and Mo_(1)consist of BCC,B2 and Zr_(5)Al_(3),in which BCC/B2 coherent microstructure is *** strengthening mechanism of BCC/B2 coherent microstructure in 873 K-aged alloy with Cr_(0.5)Mo_(0.5)was also discussed.

关键词： High entropy alloys Coherent precipitation Microstructure Lattice misfit Precipitation strengthening

Size and Dynamics of Ring Polymers under Different Topological Constraints

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第4期41卷 516-524,I0006页

作者： Jiang-Yang Mo zhen-hua wang Yu-Yuan Lu Li-Jia An State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China University of Science and Technology of China Hefei230026China

The impact of ring polymer length N and the influence of interchain and intrachain interactions on the size and dynamic behaviors of ring polymers,including the structural relaxation time τ_(R) and self-diffusion coefficient D,remain poorly understood at present due to a lack of systematic studies with relatively large N *** work addressed this issue by applying dynamic Monte Carlo simulations with independently tuned interchain and intrachain interactions to investigate the size and dynamics of the ring melts with chain lengths over a wide range of 0.2N_(e)≤N≤80N_(e)(N_(e) is the entanglement length of corresponding linear chains)under different topological constraints,including all-crossing and intercrossing *** found that it was inappropriate to treat the unknotting constraint free energy of the ring chains in the melts as the free energy contributed by the excluded volume interactions of polymers in a good *** exponents of 2.5 and 1.5 reflecting the Ndependence of τ_(R) were obtained for long ring chains in non-crossing and intra-crossing systems,respectively,suggesting that the ring chains behaved as individual clusters and exhibited Zimm-like dynamics in intra-crossing systems.A single scaling exponent of-2 reflecting the Ndependence of D was obtained for ring chains in non-crossing and intra-crossing systems,indicating that the intrachain constraints affected only the value of D,and had little influence on the scaling relationship between D and ***,the extended Stokes-Einstein relation broke down for the ring chains in the non-crossing and intra-crossing systems because the structural relaxation and translational diffusion were decoupled for the short ring systems,while both the translational diffusion and rotational relaxations,as well as diffusion at short and long time scales,were decoupled for long ring systems.

关键词： Ring polymer Topological constraint Extended Stokes-Einstein relation Monte Carlo simulation

Polymer Translocation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第5期41卷 683-698,I0007页

作者： Lu-Wei Lu zhen-hua wang An-Chang Shi Yu-Yuan Lu Li-Jia An State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China University of Science and Technology of China Hefei 230026China Department of Physics and Astronomy McMaster UniversityHamiltonOntario L8S4M1Canada

The translocation of a polymer through a pore that is much smaller than its size is a fundamental and actively researched topic in polymer *** understanding of the principles governing polymer translocation provides important guidance for various practical applications,such as the separation and purification of polymers,nanopore-based single-molecule deoxyribonucleic acid/ribonucleic acid(DNA/RNA)sequencing,transmembrane transport of DNA or RNA,and infection of bacterial cells by *** past several decades have seen great progresses on the study of polymer *** we present an overview of theoretical,experimental,and simulational stduies on polymer translocation,focusing on the roles played by several important factors,including initial polymer conformations,external fields,polymer topology and architectures,and confinement *** highlight the physical mechanisms of different types of polymer translocations,and the main controversies about the basic rules of translocation *** compare and contrast the behaviors of force-induced versus flow-induced translocations and the effects of unknotted versus knotted ***,we mention several opportunities and challenges in the study of polymer translocation.

关键词： Polymer translocation Knotted polymers Translocation time Critical flux

Divergent synthesis of aryl amines and dihydroquinazolinones via electrochemistry-enabled rhodium-catalyzed C–H functionalization

在线全文

学校读者我要写书评

暂无评论

中国科学:化学英文版 2023年第10期66卷 2863-2870页

作者： Yi-Kang Xing zhen-hua wang Ping Fang Cong Ma Tian-Sheng Mei State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesShanghai 200032China

Electrochemistry-enabled rhodium-catalyzed C–H amination and amination cyclization of arene assisted by a weakly coordinating amide have been reported. Additionally, aryl amines and dihydroquinazolinones could be obtained selectively by controlling the electric current. Mechanistic studies suggested that the amination reaction likely involves an electrochemical oxidation-induced reductive elimination of a high valent rhodium intermediate, which led to the amination reaction even proceeding smoothly at room temperature.

关键词： organic electrochemistry rhodium catalysis C-H functionalization divergent synthesis

Novel intelligent reasoning system for tool wear prediction and parameter optimization in intelligent milling

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 76-93页

作者： Long-hua Xu Chuan-zhen huang zhen wang Han-Lian Liu Shui-Quan huang Jun wang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiPeople’s Republic of China Center for Advanced Jet Engineering Technologies(CaJET) Key Laboratory of High-efficiency and Clean Mechanical Manufacture(Ministry of Education)National Experimental Teaching Demonstration Center for Mechanical Engineering(Shandong University)School of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China Institute of Manufacturing Technology Guangdong University of TechnologyGuangzhou510006People’s Republic of China

Accurate intelligent reasoning systems are vital for intelligent *** this study,a new intelligent reasoning system was developed for milling processes to accurately predict tool wear and dynamically optimize machining *** developed system consists of a self-learning algorithm with an improved particle swarm optimization(IPSO)learning algorithm,prediction model determined by an improved case-based reasoning(ICBR)method,and optimization model containing an improved adaptive neural fuzzy inference system(IANFIS)and *** results showed that the IPSO algorithm exhibited the best global convergence *** ICBR method was observed to have a better performance in predicting tool wear than standard CBR *** IANFIS model,in combination with IPSO,enabled the optimization of multiple objectives,thus generating optimal milling *** paper offers a practical approach to developing accurate intelligent reasoning systems for sustainable and intelligent manufacturing.

关键词： Improved particle swarm optimization(IPSO)algorithm Improved case-based reasoning(ICBR)method Adaptive neural fuzzy inference system(ANFIS)model Tool wear prediction Intelligent manufacturing

Revisiting the island of hexadecapoledeformation nuclei in the A≈150 mass region:focusing on the model application to nuclear shapes and masses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第2期76卷 74-88页

作者： Xiao-Yang Wei hua-Lei wang zhen-zhen Zhang Min-Liang Liu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Based on the potential-energy-surface calculation,the impact of different deformation degrees of freedom on a single-particle structure and binding energies in nuclei around^(152)Nd,located on one of the hexadecapole-deformation islands,is analyzed in a multi-dimensional deformation *** energy maps,curves and tables are presented to indicate nuclear *** calculated equilibrium deformations and binding energies with different potential parameters are compared with experimental data and other *** is found that the inclusion of the hexadecapole deformations,especially the axial one,can improve the theoretical description of both nuclear shapes and *** addition,our calculated potential-energy curve shows that a critical deformation-point,β_(2)≈0.4,exists—the triaxial(hexadecapole)deformation effect can be neglectable but the hexadecapole(triaxial)one plays an important role before(after)such a critical point.

关键词： hexadecapole deformation binding energy potential-energy-surface calculation nuclear property

DBU-catalyzed dearomative annulation of 2-pyridylacetates withα,β-unsaturated pyrazolamides for the synthesis of multisubstituted 2,3-dihydro-4H-quinolizin-4-ones

在线全文

学校读者我要写书评

暂无评论

Organic Chemistry Frontiers 2022年第1期9卷 88-94页

作者： Yao-Bin Shen Jian-Qiang Zhao zhen-hua wang Yong You Ming-Qiang Zhou Wei-Cheng Yuan National Engineering Research Center of Chiral Drugs Chengdu Institute of Organic ChemistryChinese Academy of SciencesChengdu610041China Innovation Research Center of Chiral Drugs Institute for Advanced StudyChengdu UniversityChengdu 610106China University of Chinese Academy of Sciences Beijing100049China

The reaction of 2-pyridylacetates andα,β-unsaturated pyrazolamides with DBU as the catalyst has been developed.A range of unexplored multisubstituted 2,3-dihydro-4H-quinolizin-4-ones are obtained with satisfactory yields(up to 94%)and excellent diastereoselectivities(all cases>20:1 dr)via a dearomative[3+3]annulation *** practical method also features transition metal free,mild reaction conditions,wide functional group tolerance,easy scale-up synthesis,and versatile further derivatization.

关键词： process substituted unsaturated

Laser manufacturing of spatial resolution approaching quantum limit

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie wang Hong-hua Fang zhen-Ze Li Dan wang Hong-Bo Sun State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing *** manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for *** is,however,suffering from optical diffraction ***,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size of<5 nm is *** underlying physics is that the uncertainty of local atom thermal motion dominates electron excitation,rather than the power density slope of the incident *** show that the colour centre yield in hexagonal boron nitride is transformed from stochastic to deterministic,and the emission from individual sites becomes polychromatic to *** a result,single colour centres in the regular array are deterministically created with a unity yield and high positional accuracy,serving as a step forward for integrated quantum technological applications.

关键词： quantum limit resolution