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Forging strength-ductility unity in a high entropy steel

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Journal of Materials.s.ience & Technology 2022年第18期113卷 158-165页

作者： s.J.Tsianikas Y.Chen J.Jeong s.Zhang Z.xie school of Mechanical Engineering The University of AdelaideSA 5005Australia Centre for Advanced Thin Film Materials and Devices Faculty of Materials and EnergySouthwest UniversityChongqing 400715China Max-Planck-Institut für Eisenforschung Max-Planck-Straße 1Düsseldorf 40237Germany

Fe_(72.4)Co_(13.9)Cr_(10.4)Mn_(2.7)B_(0.34)high entropy steel was prepared by magnetron *** alloy exhibits a high yield strength of 2.92±0.36 GPa while achieving appreciable plasticity of 13.7±1.9%at the ultimate compressive strength(3.37±0.36 GPa).The distribution of iron and chromium shows an un-usual,characteristic spinodal-like pattern at the nanometer scale,where compositions of Fe and Cr show strong anticorrelation and vary by as much as 20 at.%.The high strength is largely attributable to the compositional modulations,combined with fine grains with body-centered cubic(BCC)crystal structure,as well as grain boundary segregation of interstitial *** impressive plasticity is accommodated by the formation and operation of multiplanar,multicharacter dislocation slips,mediated by coherent in-terfaces,and controlled by shear *** excellent strength-ductility combination is thus enabled by a range of distinctive strengthening mechanis.s.rendering the new alloy a potential candidate for safety-critical,load-bearing structural applications.

关键词： Deformation mechanisms Micromechanical testing Compositional fluctuations Body-centered cubic High entropy steel

A reliability ass.s.ment method based on support vector machines for CNC equipment

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science China(Technological sciences) 2009年第7期52卷 1849-1857页

作者： WU Jun DENG Chao sHAO XinYu xie s Q school of Naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan 430074China state Key Laboratory of Digital Manufacturing Equipment&Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of AucklandAucklandNew Zealand

With the applications of high technology,a catastrophic failure of CNC equipment rarely occurs at normal operation *** it is difficult for traditional reliability ass.s.ment methods based on time-to-failure distributions to deduce the reliability *** paper presents a novel reliability ass.s.ment methodology to estimate the reliability level of equipment with machining performance degradation data when only a few samples are *** least squares.s.pport vector machines(Ls.s.M) are introduced to analyze the performance degradation process on the equipment.A two-stage parameter optimization and searching method is proposed to improve the Ls.s.M regression performance and a reliability ass.s.ment model based on the Ls.s.M is built.A machining performance degradation experiment has been carried out on an OTM650 machine tool to validate the effectiveness of the proposed reliability ass.s.ment methodology.

关键词： reliability ass.s.ment least squares support vector machines performance degradation radial basis function parameter optimization

On the electron-beam (EB) irradiation and grafting of acrylic monomers onto EVA copolymers

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Chinese science Bulletin 1997年第18期42卷 1549-1554页

作者： Zhang, s Wang, JQ xie, LQ Wen, CL BEIJING INsT TECHNOL SCH CHEM ENGN & MAT SCISTATE KEY LAB FLAME RETARDANT MATBEIJING 100081PEOPLES R CHINA

IN an ordinary way the grafting induced by electron and gamma preirradiations widely used for improving the compatibility of polymers in composites gives rise to an enhancement of their mechanical properties. However, very few have been reported in the flame retardancy of polymers using these sorts of techniques. Wilkie investigated the flame retardancy of photo-initiation grafted polymers. An attempt is made in this paper to try to use the EB preirradiation on EVA copolymers with different VA contents and the subsequent grafting with saponification under atmosphere and to expedite the charring of polymers upon heating. Characterization of the flammability of the preirradiated EVA copolymers grafted with acrylic monomers indicates that this approach turns out to be a promising way and worthy of doing.

关键词： electron-beam irradiation grafting flame retardancy EVA copolymers.

Diffusion behavior of Cr in gradient nanolaminated surface layer on an interstitial-free steel

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Journal of Materials.s.ience & Technology 2019年第3期35卷 460-464页

作者： s.L.xie Z.B.Wang K.Lu shenyang National Laboratory for Materials.s.ience Institute of Metal Research Chinese Academy of Sciences school of Materials.s.ience and Engineering University of Science and Technology of China

Nanolaminated structures composed of low-angle grain boundaries(LAGBs) poss.s. high thermal stability. In this paper, a gradient nanolaminated(GNL) surface layer with smooth finish was fabricated on an interstitial-free steel by means of surface mechanical rolling treatment. Microstructural observations demonstrated that the average lamellar thickness is about 80 nm in the topmost surface layer and increas.s.with increasing depth. High thermal stability was confirmed in the GNL surface layer after annealing at 500℃. Diffusion measurements.s.owed that effective diffusivity of Cr in GNL layer is 4–6 orders of magnitude higher than lattice diffusivity within the temperature range from 400 to 500℃. This might be attributed to numerous LAGBs or dislocation structures with a higher energy state in the GNL surface layer. This work demonstrates the possibility to advanced chromizing(or other surface alloying)process.s.of steels with formation of GNL surface layer, so that a thicker alloyed surface layer with a stable nanostructure is achieved.

关键词： Gradient nanolaminated structure Interstitial-free steel Diffusion Low-angle grain boundary surface mechanical rolling treatment

EXPERIMENTAL INVEsTIGATION AND THERMODYNAMIC CALCULATION ON PHAsE PRECIPITATION OF INCONEL 740

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Acta Metallurgica sinica(English Letters) 2006年第6期19卷 425-431页

作者： s.Q.Zhao Y.Jiang J.X.Dong X.s.xie Department of Physics Ningxia UniversityYinchuan 750021China Department of Materials.s.ience The Northwest Second Nationalities InstituteYinchuan 750021China High Temperature Materials Research Laboratories University of Science and Technology BeijingBeijing 100083China

A novel nickel-based superalloy INCONEL 740 was under development for application in ultra-supercritical superheater tubers above 750℃. The precipitation behaviors of η phase and γ' particles of the alloy were investigated through experimental study and phase computation. Experimental results.s.owed that η phase formed a Widmanst?tten pattern structure following long-term exposure at elevated temperatures and that the coarsening of γ' particle follows a cube rate law:r-3 ∝ t. Thermodynamic calculation results.s.owed that Al and Ti had an important effect on the precipitation behavior of γ' andη phas.s. Two suggested novel modified alloys, wherein the Al and Ti contents were modified, were designed and melted for the experimental study. The preliminary results indicated that the modified alloys exhibited higher structural stability following long-term exposure at 750℃ till 5000h.

关键词： superalloy INCONEL 740 precipitate thermodynamic calculation

DsC AND TEM sTUDY OF ULTRA HIGH sTRENGTH ALUMINUM ALLOY

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Acta Metallurgica sinica(English Letters) 2004年第4期17卷 554-559页

作者： G.s.xie Y.Zeng H.Ding Hunan Electric Power Test & Research Institute Changsha 410007 ChinaMaterial Department Central South University Changsha 410083 ChinaMaterial Department Wuhan University Wuhan 430072 China

In this paper, the effect of RRA treatment on the microstructure evolution of a high strength aluminum alloy was investigated using DsC, TEM and sADP technology. The results.s.ow that the precipitation resulting from RRA is extremely fine and distributed homogeneously in the grains, being slightly coarser and more stable than that of T6 temper. While, the grain-boundary precipitation is very close to that of the alloy at T73 temper, being coarse and discontinuous. High retrogression temperature and long retrogression time leads to a more stable microstructure after re-aging.

关键词： DsC TEM RRA Al-Zn-Mg-Cu alloy

Composite recommendations： from items to packages

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Frontiers of Computer science 2012年第3期6卷 264-277页

作者： Min xie Laks V. s. LAKsHMANAN Peter T. WOOD Department of Computer science University of British Columbia Vancouver V6T 1Z4 Canada Department of Computer science and Information s.s.ems Birkbeck University of London London WCIE 7HX UK

Classical recommender s.s.ems provide users with a list of recommendations where each recommendation cons.s.s of a single item, e.g., a book or DVD. However, sev- eral applications can benefit from a s.s.em capable of recom- mending packages of items, in the form of sets. sample appli- cations include travel planning with a limited budget （price or time） and twitter users wanting to select worthwhile tweeters to follow, given that they can deal with only a bounded num- ber of tweets. In these contexts, there is a need for a s.s.em that can recommend the top-k packages for the user to choose from. Motivated by these applications, we consider composite recommendations, where each recommendation compris.s.a set of items. Each item has both a value （rating） and a cost associated with it, and the user specifies a maximum total cost （budget） for any recommended set of items. Our composite recommender s.s.em has access to one or more component recommender s.s.ems focusing on different do- mains, as well as to information sources which can provide the cost associated with each item. Because the problem of deciding whether there is a recommendation （package） whose cost is under a given budget and whose value exceeds.s.me threshold is NP-complete, we devise several approximation algorithms for generating the top-k packages as recommen- dations. We analyze the efficiency as well as approximation quality of these algorithms. Finally, using two real and two synthetic datasets, we subject our algorithms to thorough ex- perimentation and empirical analys.s. Our findings attest tothe efficiency and quality of our approximation algorithms for the top-k packages compared to exact algorithms.

关键词： recommendation algorithms optimization,top-k query processing

Exclusive π^(0) production at EIC of China within handbag approach

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Chinese Physics C 2022年第12期46卷 50-57页

作者： s.V.Goloskokov Ya-Ping xie Xurong Chen Laboratory of Theoretical Physics Joint Institute for Nuclear ResearchDubna 141980MoscowRussia Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of sciences Beijing 100049China Institute of Quantum Matter South China Normal UniversityGuangzhou 510006China

Exclusive π^(0) electroproduction is analyzed within the handbag approach based on Generalized Parton Distribution(GPDs)*** consider the leading-twist contribution together with the transversity *** is.s.own that the transversity GPDs H_(T) and E_(T) are essential in the description of the π^(0) cross *** for the future Electron-Ion Collider of China(EicC)energy range are *** is found that transversity dominanceσ_(T)>>σ_(L),observed at low energies,is valid up to the EicC energy range.

关键词： general parton distributions nucleon structure deep virtual meson production

Long-term effects of gravel―sand mulch on soil organic carbon and nitrogen in the Loess Plateau of northwestern China

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Journal of Arid Land 2015年第1期7卷 46-53页

作者： Yang QIU ZhongKui xie YaJun WANG sukhdev s MALHI JiLong REN Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Northeast Agricultural Research Foundation (NARF)

Gravel-sand mulch has been used for centuries to conserve water in the Loess Plateau of north- western China. In this.s.udy, we ass.s.ed the influence of long-term （1996-2012） gravel-sand mulching of cultiv- ated soils on total organic carbon （TOC）, light fraction organic carbon （LFOC）, microbial biomass carbon （MBC）, total organic nitrogen （TON）, particulate organic carbon （POC）, mineral-associated organic carbon （MOC）, perma- nganate-oxidizable carbon （KMnO4-C）, and non-KMnO4-C at 0-60 cm depths. Mulching durations were 7, 11 and 16 years, with a non-mulched control. Compared to the control, there was no significant and cons.s.ently positive effect of the mulch on TOC, POC, MOC, KMnO4-C and non-KMnO4-C before 11 years of mulching, and these organic C fractions generally decreased significantly by 16 years. LFOC, TON and MBC to at a 0-20 cm depth in- creased with increasing mulching duration until 11 years, and then these fractions decreased significantly between 11 and 16 years, reaching values comparable to or lower than those in the control. KMnO4-C was most strongly correlated with the labile soil C fractions. Our findings.s.ggest that although gravel-sand mulch may conserve soil moisture, it may also lead to long-term decreas.s.in labile soil organic C fractions and total organic N in the study area. The addition of manure or composted manure would be a good choice to reverse the soil deterioration that occurs after 11 years by increasing the inputs of organic matter.

关键词： gravel mulch mulching duration permanganate-oxidizable carbon light fraction organic carbon microbial biomass carbon