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Acta Metallurgica sinica(English Letters) 2004年第6期17卷 830-834页

作者： y.H.li J.Wang y.s.li y.Kshan Dep.ofMaterialscienceandEngineering ShenyangLigongUmversityShenyang110168China InstituteofIndustry NingboPolytechnicNingbo315800China schoolofMaterial＆ChemicalEngineering SouthernInstituteofMetallurgy＇Ganzhou341000China InstituteofMetalResearch TheChineseAcademyofSdencesShenyang110016China

Recrystallization behavior of a low carbon X70 pipeline steel was studied in the plane strain compression condition. It was found that the dynamic recovery but no dynamic recrystal- lization occurred in the current ex... 详细信息

关键词： pipeline steel, plane strain compression, recrystallization, austenite grain boundary

IMPROVED PROCEssING FOR MICROsTRUCTUREs AND MECHANICAL PROPERTIEs OF A COMMERCIAL PIPEliNE sTEEL

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Acta Metallurgica sinica(English Letters) 2005年第2期18卷 121-128页

作者： y.C.Wang y.s.li M.C.Zhao K.yang schoolofMaterial＆ChemicalEngineering JiangxiUniversityofScienceandTechnologyGanzhou341000China InstituteofMetalResearch TheChineseAcademyofSciencesShenyang110016China

The transformation productions of hot-deformation simulation experiments were investigated using a Gleeble-1500 hot simulator for a commercial pipeline steel. Based on the investigation results, the improved thermo-mechanical control processing (TMCP) schedules containing a two stage multi-pass controlled rolling coupled with moderate cooling rates were applied to hot rolling experiments and acicular ferrite dominated microstructure was obtained. Microstructures and mechanical properties of hot rolled plates were related to TMCP processing, and regression equations describing the relation between processing parameters and mechanical properties in the current TMCP were developed, which could be used to predict mechanical properties of the experimental steel during commercially processing. It was found that with an increase in cooling rate after hot rolling, grain size in the microstructure became smaller, the amount of polygonal ferrite decreased and acicular ferrite increased, and accordingly mechanical properties increased.

关键词： hot-deformation simulation thermo-mechanical control processing acicular ferrite dominated microstructure

Gradient structured Copper by Rotationally Accelerated shot Peening

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Journal of Materials science & Technology 2017年第7期33卷 758-761页

作者： X.Wang y.s.li Q.Z.ang y.H.Zhao y.T.Zhu Nano structural Materials Center School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China school of Mechanical Engineering Nanjing University of Science and Technology Nanjing 210094 China Department of Materials science and Engineering North Carolina State University Raleigh NC 27695 USA

A new technology-rotationally accelerated shot peening（RAsP）, was developed to prepare gradient structured materials. By using centrifugal acceleration principle and large steel balls, the RAsP technology can produce much higher impact energy compared to conventional shot peening. As a proof-of-concept demonstration, the RAsP was utilized to refine the surface layer in pure copper（Cu） with an average grain size of 85 nm. The grain size increases largely from surface downwards the bulk, forming an800 ？m thick gradient-structured surface layer and consequently a micro-hardness gradient. The difference between the RAsP technology and other established techniques in preparing gradient structured materials is discussed. The RAsP technology exhibits a promoting future for large-scale manufacturing of gradient materials.

关键词： Microstructure Rotationally accelerated shot peening Gradient structure Hardness Copper

Microstructural evolution and mechanical properties of Mg-9.8Gd-2.7y-0.4Zr alloy produced by repetitive upsetting

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Journal of Materials science & Technology 2018年第7期34卷 1067-1075页

作者： H.Zhou H.y.Ning X.L.Ma D.D.yin L.R.Xiao X.C.sha y.D.yu Q.D.Wang y.s.li Nano and Heterogeneous Materials Center School of Materials and EngineeringNanjing University of Science and TechnologyNanjing210094China Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China school of Mechanical and Electrical Engineering Heilongjiang Institute of TechnologyHeilongjiang 150050China school of Materials science and Engineering Harbin University of Science and TechnologyHarbin 150040China Department of Materials science&Engineering North Carolina State UniversityRaleighNC 27695USA Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China National Engineering Research Center of light Alloys Net Forming and State Key Laboratory of Metal Matrix CompositeShanghai Jiao Tong University200240 ShanghaiChina

A newly developed severe plastic deformation （sPD） technique, i.e. repetitive upsetting （RU）, is employed to improve the strength and ductility of a Mg-Gd-y-Zr alloy. During the RU processing, dynamic recrystallization occurs in the Mg alloy, which leads to a significant grain refinement from 11.2 p.m to 2.8 μm. The yield strength （ys）, ultimate tensile strength （UTs） and elongation increase simultaneously with increasing RU passes. The microstructural evolution is affected by processing temperatures. Dynamic recrystallization prevails at low temperatures, while dynamic recovery is the main effect factor at high temperatures. Texture characteristics gradually become random during multiple passes of RU processing, which reduces the tension-compression asymmetry of the Mg-Gd-y-Zr alloy. 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials science ＆ Technology.

关键词： severe plastic deformation (sPD) Repetitive upsetting (RU) Mg-RE alloy Mechanical properties

COMPARIsON OF PERFORMANCE OF VARIOUs MULTIPLE-MODEL ENsEMBLE TECHNIQUEs IN FORECAsTING INTENsITy OF TROPICAL CyCLONE

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Tropical Cyclone Research and Review 2012年第3期1卷 353-360页

作者： NURsALLEH K.CHANG L.s.LEE y.s.li Malaysian Meteorological Department Malaysia Hong Kong Observatory Hong KongChina

The objective of this study was to explore an optimal multiple-model ensemble technique to aid the forecasting of tropical cyclone(TC) intensity. The maximum winds of TCs as forecast by the models of the European Centre for Medium-Range Weather Forecasts, the Japan Meteorological Agency and the National Centers for Environmental Prediction for the period from July 2010 to October 2011 were studied. Performance of various multiple-model ensemble techniques, including equally weighted ensemble, weighted ensemble based on initial forecast error, weighted ensemble based on 12-hour forecast error, bias-corrected equally weighted ensemble and bias-corrected weighted ensemble based on initial forecast error, was verified against the TC intensities post-analysed by the Hong Kong Observatory. Results showed that the equally weighted ensemble technique generally outperformed the best of the individual models and other multiple-model ensemble techniques. The mean absolute errors of the equally weighted ensemble technique were the lowest at 12, 24 and 36-hour forecasts, and the error spreads were generally the smallest from 12 to 72-hour forecasts.

关键词： COMPARIsON TECHNIQUEs TROPICAL CyCLONE

Reactive destabilization and bidirectional catalyzation for reversible hydrogen storage of liBH_(4) by novel waxberry-like nano-additive assembled from ultrafine Fe_(3)O_(4) particles

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Journal of Materials science & Technology 2024年第6期173卷 63-71页

作者： s.Wang M.H.Wu y.y.Zhu Z.L.li y.X.yang y.Z.li H.F.liu M.X.Gao Department of Material science Shenzhen MSU-BIT UniversityShenzhen 518172China state Key Laboratory of silicon and Advanced semiconductor Materials&school of Materials science and Engineering Zhejiang UniversityHangzhou 310027China Institute of Resources Utilization and Rare Earth Development State Key Laboratory of Rare Metals Separation and Comprehensive UtilizationGuangdong Provincial Key Laboratory of Rare Earth Development and ApplicationGuangdong Academy of SciencesGuangzhou 510650China Institute of science and Technology for New Energy Xi’an Technological UniversityXi’an 710021China National supercomputing Center in shenzhen Shenzhen 518055China

liBH_(4) containing 18.5 wt.%H_(2) is an attractive high-capacity hydrogen storage material,however,it suffers from high operation temperature and poor ***,a novel and low-cost bifunctional additive,waxberry-like Fe_(3)O_(4) secondary nanospheres assembled from ultrafine primary Fe_(3)O_(4) nanoparticles,is synthesized,which exhibits significant destabilization and bidirectional catalyzation towards(de)hydrogenation of liBH_(4).With an optimized addition of 30 wt.% waxberry-like Fe_(3)O_(4),the system initiated dehydrogenation below 100℃ and released a total of 8.1 wt.%H_(2) to 400℃.After 10 cycles,a capacity retention of 70% was achieved,greatly superior to previously reported oxides-modified *** destabilizing and catalyzing mechanisms of waxberry-like Fe_(3)O_(4) on liBH_(4) were systematically analyzed by phase and microstructural evolutions during dehydrogenation and hydrogenation cycling as well as density functional theory(DFT)*** present work provides new insights in developing advanced nano-additives with unique structural and multifunctional designs towards liBH4 hydrogen storage.

关键词： liBH_(4) Hydrogen storage Waxberry-like Fe_(3)O_(4) Destabilization Catalysis

The effect of southeast Asian biomass burning on aerosol and trace gases at a remote site of southwest China

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The effect of Southeast Asian biomass burning on aerosol and...

Ren-integrable and ren-symmetric integrable systems

第九届全国气溶胶会议暨第三届海峡两岸气溶胶技术研讨会

作者： C.y.Chan~1 s.C.Zou~2 L.y.Chan~1 y.s.li~1 1 Department of Ctvil and structural Engineering,The Hong Kong Polytechnic University,Hong Kong,China 2 Department of Chemistry,Zhongshan University,Guangzhou,China

Aerosols(PM and PM)and trace gases were measured at a remote mountain site of Tengchong(25.01°N,98.3°E,1960 m a.s.l.)located on southeastern Tibetan Plateau in southwest China in the spring of *** O,CO,PM and PM had average concentrations of 26 ppb,179 ppb,28 and 34μg/m respectively during the sampling ***,high levels of pollution with hourly average 03,CO,PM and PM concentrations up to 59,678 ppb and,158 and 137μg/m respectively were *** average concentration of water soluble potassium ion (K,0.18 and 0.23μg/m for PM and PM respectively),a tracer for biomass burning was lower when comparing with other rural sites of ***,high concentrations of K were observed at a pollution episode(May 4-6,2004).Meteorological analysis suggested that the polluted air mass was caused by biomass burning emission in the southeast Asian(sE Asia) *** preliminary results thus suggested that the emissions from sE Asia and south Asia have relatively stronger impacts on the abundance of aerosols and trace gases in the background atmosphere of southwest China.

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Communications in Theoretical Physics 2024年第3期76卷 62-69页

作者： s y Lou school of Physical science and Technology Ningbo UniversityNingbo315211China

A new type of symmetry,ren-symmetry,describing anyon physics and corresponding topological physics,is ***-symmetry is a generalization of super-symmetry which is widely applied in super-symmetric physics such as super-symmetric quantum mechanics,super-symmetric gravity,super-symmetric string theory,super-symmetric integrable systems and so *** and Grassmann numbers are,in some sense,dual conceptions,and it turns out that these conceptions coincide for the ren situation,that is,a similar conception of ren-number(R-number)is devised for *** particular,some basic results of the R-number and ren-symmetry are exposed which allow one to derive,in principle,some new types of integrable systems including ren-integrable models and ren-symmetric integrable *** examples of ren-integrable KdV-type systems and ren-symmetric KdV equations are explicitly given.

关键词： symmetries integrable systems anyon physics extended supersymmetry ren-symmetry

Effect of Eu3+,Bi3+,and li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and li+.Our results indicate that li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of li + Photoluminescence sensitizer Rare earths

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On B(5,20)2-Groups

Algebra Colloquium 2024年第3期31卷 429-440页

作者： E.A.Alhassan y.L.Tan y.li school of Mathematical sciences Jiangsu UniversityZhenjiangJiangsu 212013China Department of Mathematics Brock UniversitySt.CatharinesOntario L2S 3A1Canada

A finite group G is said to be a B(n,k)group if for any n-element subset[a_(1),…,a_(n)]of G,|{a_(i)a_(j)|1≤i,j≤n}|≤*** is of interest to characterize the structure of B(n,k)groups for n(n+1)/2≤k≤n^(2)-*** B(5,k)groups for 15≤k≤19 have been investigated by several *** this paper,we give a complete characterization of B(5,20)2-groups by showing there are five classes of such groups which are nontrivial and nonabelian.

关键词： B(n,k)groups small squaring property central extension GAP