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Crystallization Kinetics of Pr8Fe86-xZrxB6 Amorphous Alloys

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Journal of Iron and Steel Research International 2002年第2期9卷 49-52页

作者： LIU Jian-hua zhang Peng-yue zhang Jing-wu LI Hui zhang xiang-yi Yanshan University

Two experimental methods were adopted to verify the correctness and practicability of the shape meter method: one is to roll aluminum plate, calculate the shape stiffness of mill and rolled piece, and then measure aluminum plate crown to verify shape stiffness equation; the other is to calculate the measured off line data of hot continuous roll and verify the shape mathematical model for measuring and controlling by self adaptation method.

关键词： shape meter method shape stiffness equation mathematical model post calculation self adaptation

Influence of vibration on the lubrication effect of a splash-lubricated gearbox

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第4期25卷 324-339页

作者： yi LIU Kailin zhang Shuai SHAO Hongxu xiang Zhijian YE State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

In this study,we investigate the effect of rail vibrations on the lubrication and efficiency of a splash-lubricated gearbox;specifically,the gearbox of a rail-transit vehicle.A high-fidelity 3D numerical model of the gearbox in a moving reference system is described,as well as computational fluid dynamics(CFD)simulations of the gearbox with different vibration *** effects of rotational speed,oil-immersion depth,and different oil-injection volume rates on lubrication and efficiency are *** propose a method of evaluating the internal lubrication condition of a splash-lubricated gearbox and quantitatively compare the effects of different operating parameters on lubrication and ***,our experiment to verify the feasibility of the simulation method is *** results show that with vibration,the churning loss and oil supply for the bearings are significantly higher than those under static *** addition,among different vibrational directions,lateral vibration has the greatest influence on the lubrication condition and efficiency of the *** the studied railway-vehicle gearbox,the best lubrication condition is achieved at a rotational speed of 1600 r/min and an oil-immersion depth of two times the tooth height(***).Rotational speed is the operating parameter that has the most significant effect on the lubrication and efficiencyofthegearbox.

关键词： Comprehensive lubrication evaluation Churning loss Moving reference system Splash lubrication Vibrational excitation Gearbox

Sandwich structures with tapered tubes as core:A quasi-static investigation

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Defence Technology（防务技术） 2024年第3期33卷 447-462页

作者： Xinmei xiang Dehua Shao Xin zhang Umer Sharif Ngoc San Ha Li xiang Jing zhang Jiang yi School of Civil Engineering Guangzhou UniversityGuangzhouChina Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhenGuangdongChina School of Engineering Centre for Innovative Structures and MaterialsRMIT UniversityMelbourneAustralia China Southern Airlines Co. LtdShenzhen BranchShenzhen518000China

In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without *** results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube ***,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their ***,the tapered corrugated tubes'resistance to oblique impacts was *** to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical *** conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall *** and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10.

关键词： Sandwich structure Corrugated tube Tapered tube Quasi-static Energy absorption

Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： yi-Cong Wang Hui Zhat Pei-yi Cheng Shu zhang xiang-Wei Liu yi-Xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Application of electromagnetic metallurgy in continuous casting: A review

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Progress in Natural Science:Materials International 2024年第1期34卷 1-11页

作者： Jiale Li yi Nian xiang Liu Youcheng Zong Xinyu Tang Chaojie zhang Liqiang zhang The Intelligent Metallurgy Research Institute School of Metallurgical Engineering Anhui University of Technology

The standards within the global steel industry are constantly advancing, necessitating increasingly rigorous quality control protocols during the continuous casting process. Central to the challenges faced in this domain are persistent defects such as central segregation, V-shaped segregation, and center porosity, which significantly impede the production of high-caliber steel products. The discipline of electromagnetic metallurgy has emerged as a critical solution in reducing these defects, thereby enhancing the efficiency and stability of continuous casting operations. Its demonstrated effectiveness has led to its widespread implementation across global and domestic steel production industries. This paper aims to deliver a comprehensive examination of electromagnetic metallurgy's impact on the final stages of solidification in continuous casting, along with its contributions to the heating and purification processes within the tundish. Additionally, it will explore the potential advancements and applications of this technology in the evolving sphere of continuous casting.

关键词： continuous casting Quality control Final electromagnetic stirring Induction heating Electromagnetic purification

Controllable Construction of Vinyl Sulfones and β-Keto Selenosulfones via Selective Oxidative Sulfonylation of Alkenes

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Chinese Journal of Chemistry 2024年第12期42卷 1367-1372页

作者： xiang Liu Yuan zhang yi Zheng Changfeng Huang Hua Cao School of Chemistry and Chemical Engineering Guangdong Pharmaceutical UniversityZhongshanGuangdong 528458China

Comprehensive Summary The selective oxidative sulfonylation of alkenes with selenium sulfonate depended on the reaction *** electrochemical C—H sulfonylation proceeded smoothly to afford(E)-vinyl sulfones with good selectivity in an undivided cell without external *** aerobic trifunctionalization of alkenes occurred in the presence of KI in the air,which providesβ-keto selenosulfones via the formation of C—O,C—S,and C—Se bonds in *** control experiments,a plausible mechanism is proposed to rationalize the experimental results.

关键词： Synthetic methods Alkenes Difunctionalization Selenylation Sulfonylation

Evaluation on cutting performance of novel PDC cutter for pipe jacking machine

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Underground Space 2024年第1期14卷 34-52页

作者： Long-Chuan Deng yi-xiang Yuan Xiao-Zhao Li Qian-Wei Zhuang Chi zhang yi-Wei Chen School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu 210023China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200232China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

It is inevitable to cut reinforced concrete(RC)appeared in cross passage of city metro by cutting tools when constructing in densely populated *** previous cutters employed to cut RC are insufficient and easily damaged,so a new polycrystalline diamond compact(PDC)cutter is used to solve this *** on the theoretical analysis of cutting mechanism,both circular and tapered PDC cutters with cutting edge angle of 90and negative front rack angle of 10are used to cut *** peeling and breaking patterns of cutting concrete are proposed,the nodular and grainy chips are the preferred modes in cutting steel *** LS-DYNA is employed to investigate the cutting performance in *** simulation results show that the average and peak cutting forces increase with the growth of penetration depth,cutting speed,and roundness,and subsequently the recommended penetration depth less than 1.2 mm is obtained to cut RC due to the existence of steel ***,the linear cutting platform is adopted to investigate the force ability and damage state of PDC *** is concluded that the cutting force increases abruptly and fluctuates heavily when cutting the coarse *** patterns occurred in both numerical and experimental results are generally ***,the steel bar is pulled out and the PDC cutter is damaged at the penetration depth of 0.8 mm,while a good cut occurs at the penetration depth of 0.3 *** tapered PDC cutter with a relatively low cutting force is prone to be broken compared with circular PDC *** is suggested that the circular PDC cutter at the penetration depth of 0.3 mm should be used to cut RC in practical engineering.

关键词： PDC cutter RC Pipe jacking machine Linear cutting tests Damage and wear LS-DYNA

Ballistic performance of spaced multi-ply soft fabrics: Experimental and numerical investigation

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Defence Technology（防务技术） 2024年第4期34卷 143-155页

作者： Zhongwei zhang Xiaoning Yang Yuan Lin Ziming Xiong Yuhang xiang yi Zhou Mingyang Wang State Key Laboratory of Explosion&Impact and Disaster Prevention&Mitigation Army Engineering University of PLANanjing 210007China School of Mechanical Engineering Nanjing University of Science&TechnologyNanjing 210007China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China Postdoctoral Station of Civil Engineering Army Engineering University of PLANanjing 210007China

It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap *** the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.

关键词： Energy absorption capability Ply gap Ballistic performance The front ply The rear ply

Solidification of Undercooled Ge_(73.7)Ni_(26.3) Alloy Subjected to Sputtering-Deposition of Ni Clusters

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Chinese Physics Letters 1998年第2期15卷 149-151页

作者： LIU Ri-ping JING Qin CAO Li-min zhang Ming zhang Fu-xiang zhang xiang-yi ZHAO Jian-hua HE Duan-wei XU ying-fan WANG Wen-kui Institute of Physics Chinese Academy of SciencesBeijing 100080 Institute of Materials Engineering Yanshan UniversityQinhuangdao 066004

Undercooled melt of Ge_(73.7)Ni_(26.3) alloy sample floated on B_(2)O_(3 ) melt was subjected to sputtering-deposition of Ni clusters on cooling to induce *** initial temperature of solidification was 975 *** undercoolingΔT was 134 K with respect to the melting temperature of the primary phase *** the cooling curve existed dual recalescences representing the transformation of the primary phase(Ge)and the eutectics(Ge+GeNi)*** for the sample unsputtered,only a single exothermic peak presented on the cooling curve with the initial solidification temperature of 904K and undercooling of *** observation of the microstructure proved that the Ge phase primarily formed in the sputtering experiment was now formed together with the formation of the eutectics in the experiment without sputtering.

关键词： solidification eutectic microstructure