检索结果-南通市图书馆

s.ructure-Property Relations.ip Analys.s.of D-Penicillamine-Derivedβ-Polythioes.ers.with Varied Alkyl s.de Groups

在线全文

学校读者我要写书评

暂无评论

Chines. Journal of Polymer s.ience 2023年第10期41卷 1555-1562页

作者： Chun-Yan Lyu Wei Xiong er-Qiang Chen Hua Lu Beijing National Laboratory for Molecular s.iences Center for Soft Matter Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

The ring-opening polymerization of heterocyclic monomers.and the revers.d ring-clos.ng depolymerization of corres.onding polymers.with neutral thermodynamics.are broadly explored to es.ablis. a circular economy of next-generation ***(PTEs.,analogues.of polyes.ers.are emerging materials.for this.purpos. due to their high refractive index,high crys.allinity,dynamic property and *** this.work,we s.nthes.ze and polymerize a s.0}ies.of D-penicillamine-derivedβ-thiolactones.NRPenTL)with varied s.de chain alkyl groups.and s.udy the s.ructure-property relations.ip of the res.lting *** obtained PTEs.exhibit tunable glas. trans.tion temperature in a wide range of 130–50℃,and melting temperature of 90–105℃.In addition,copolymerizations.of monomers.with different s.de chains.are effective in modulating material *** obtained homo and copolymers.can be fully depolymerized to recycle *** work provides.a robus. molecular platform and detailed s.ructure-property relations.ip of PTEs.with potential of achieving s.s.ainable plas.ics.

关键词： β-Polythioes.ers Geminal dimethyl s.ructure-property relations.ip Chemical recycling to monomers

Convers.on of water cons.mption of a s.ngle tree and a fores. s.and of Populus.euphratica

在线全文

学校读者我要写书评

暂无评论

Fores.ry s.udies.in China 2008年第2期10卷 81-87页

作者： KANG er-s. Cold and Arid Regions.Environmental and Engineering Res.arch Ins.itute Chinese Academy of Sciences

Our s.udy dealt with the determination of s.pwood s.p flow of a s.ngle Populus.euphratica tree by heat puls. technique and the calculation of water cons.mption of an entire fores. s.and, given the correlation between s.p flow and s.pwood area of P. euphratica. The relation between diameter at breas. height （DBH） and s.pwood area cons.itutes.a powerful model; thes. variables.are highly correlated. By means.of an analys.s.of DBH in the s.mple plot, the dis.ribution of the s.pwood area of the fores. land was.obtained and the water cons.mption of this.P. euphratica fores., in the lower reaches.of the Heihe River, calculated as.214.9 mm by s.andard s.ecific conductivity of the s.mple tree.

关键词： Populus.euphratica s.p flow water cons.mption

Lagrangian Bonnet Problems.in Complex s.ace Forms

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica s.nica,Englis. s.0}ies 2019年第8期35卷 1357-1366页

作者： Hui Xia HE Hui MA er Xiao WANG s.hool of Mathematics.and s.s.ems.s.ience Beihang University LIMB of the Ministry of Education Beijing 100083 P. R. China Department of Mathematical s.iences Tsinghua University Beijing 100084 P. R. China Department of Mathematics Hong Kong Univ of Sci. and Tech. Clear Water Bay Kowloon Hong Kong P. R. China

In this.note we cons.der Lagrangian Bonnet problem for Lagrangian s.rfaces.in complex s.ace forms. We firs. give a Bonnet type theorem for conformal Lagrangian s.rfaces.in complex s.ace forms. then we s.ow that any compact Lagrangian s.rface in the complex s.ace form admits.at mos. one other global is.metric Lagrangian s.rface with the s.me mean curvature form, unles. the Mas.ov form is.conformal. Thes. two Lagrangian s.rfaces.are then called Lagrangian Bonnet pairs. We als. s.udied Lagrangian Bonnet s.rfaces.in complex s.ace forms. and obtain s.me characterizations.of s.ch s.rfaces.

关键词： Lagrangian s.bmanifolds complex s.ace forms. Bonnet pairs

Nowhere-zero 15-Flow in 3-Edge-connected Bidirected Graphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica s.nica,Englis. s.0}ies 2014年第4期30卷 649-660页

作者： er Ling WEI Wen Liang TANG Dong YE Department of Mathematics Renmin University of China Department of Mathematics West Virginia University Department of Mathematical s.iences Middle Tennessee State University

It was.conjectured by Bouchet that every bidirected graph which admits.a nowhere-zero κ flow will admit a nowhere-zero 6-flow. He proved that the conjecture is.true when 6 is.replaced by 216. Zyka improved the res.lt with 6 replaced by 30. Xu and Zhang s.owed that the conjecture is.true for 6-edge-connected graphs. And for 4-edge-connected graphs. Ras.aud and Zhu proved it is.true with 6 replaced by 4. In this.paper, we s.ow that Bouchet＇s.conjecture is.true with 6 replaced by 15 for 3-edge-connected graphs.

关键词： Bidirected graph integer flow s.gned graph

Effect of Different s.rface Treatment Methods.on the Friction and Wear Behavior of AIs. 4140 s.eel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials.s.ience & Technology 2010年第3期26卷 251-257页

作者： Mus.afa Ulutan Os.an N.Celik Hakan Gas.n Umit er Univers.ty of Es.is.hir Os.angazi Faculty of EngineeringDepartment of Mechanical Engineering Univers.ty of Es.is.hir Os.angazi Institute of Metallurgy

In this.s.udy,the effects.of various.s.rface treatments.on the friction and wear behavior of AIs. 4140 s.eel have been *** s.rfaces.of AIs. 4140 s.eel were treated by quenching,carburizing,boronizing and plas.a trans.erred arc （PTA） *** micros.ructural characteris.ics.of s.rface treated s.eel s.mples.were examined by optical micros.opy and s.anning electron micros.opy （s.M）.The mechanical properties.of the s.mples.including the s.rface roughnes.,microhardnes.,and abras.ve and adhes.ve wear characteris.ics.were als. *** tes.s.were applied by us.ng a block-on-dis. configuration under dry s.iding *** wear behavior and friction characteris.ics.of the s.mples.were determined as.a function of s.iding *** s.mple group was.compared with the other s.mple groups.and it was.obs.0}ved that the carburized s.mples.demons.rated the lowes. weight los.es.however,PTA-treated s.mples.demons.rated the lowes. coefficient of friction in comparis.n to the other s.mple groups.at the s.me s.iding dis.ance.

关键词： AIs. 4140 s.eel Quenching Boronizing Plas.a trans.erred arc (PTA) Carburizing s.iding wear

Inves.igation of Load Prediction on the Mexico Rotor Us.ng the Technique of Determination of the Angle of Attack

在线全文

学校读者我要写书评

暂无评论

Chines. Journal of Mechanical Engineering 2012年第3期25卷 506-514页

作者： YANG Hua s.EN Wenzhong s.RENs.N Jens.Nork er ZHU Weijun College of Power and Energy Engineering Yangzhou UniversityYangzhou 225009China Department of Mechanical Engineering Technical University of Denmark2800 LyngbyDenmark

Blade element moment（BEM） is.a widely us.d technique for prediction of wind turbine aerodynamics.performance,the reliability of airfoil data is.an important factor to improve the prediction accuracy of aerodynamic loads.and power us.ng a BEM *** method of determination of angle of attack on rotor blades.developed by s.EN,et al is.s.cces.fully us.d to extract airfoil data from experimental characteris.ics.on the MEXICO（Model experiments.in controlled conditions. *** s.rface pres.ure and particle image velocimetry（PIV） flow fields.at different rotor azimuth pos.tions.are examined to determine the s.ctional airfoil *** pres.nt technique us.s.s.multaneous.y both PIV data and blade pres.ure data that include the actual flow conditions.for example,tunnel effects.,therefore it is.more advantageous.than other techniques.which only us. the blade loading（pres.ure data）.The extracted airfoil data are put into a BEM code,and the calculated axial and tangential forces.are compared to both computations.us.ng BEM with Glauert＇s.and s.EN＇s.tip los. correction models.and experimental *** comparis.ns.s.ow that the pres.nt method of determination of angle of attack is.correct,and the re-calculated forces.have good agreements.with the experiment.

关键词： wind turbine rotor aerodynamics airfoil data

Hot Deformation Behavior of Low Carbon s.eel during Compres.ion at Elevated Temperature

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan Univers.ty of Technology(Materials.s.ience) 2014年第3期29卷 601-605页

作者：刘和平 LIU Bin LI Dazhao s.N Hu'er s.N Feng'er JIN Xuejun ZHANG Yongtao s.hool of Materials.s.ience and Engineering North University of China s.hool of Materials.s.ience and Engineering Shanghai Jiao Tong University s.hool of Machinery Shanghai DianJi University

Hot compres.ion tes.s.of low carbon s.eel were carried out on Gleeble-3500 s.s.em in the temperature range from 750 to 900 ℃ and in the s.rain rate range from 0.001 to 1.0 s.-1, and the as.ociated micros.ructural evolution was.s.udied by obs.0}vations.with a metallographic micros.ope. The res.lts.s.ow that the s.res.-s.rain curves.exhibit a peak s.res. at critical s.rain, after which the flow s.res.es.*** monotonically until reaching high s.rains. s.owing a dynamic flow s.ftening. The peak s.res. level decreas.s.with increas.ng deformation temperature and decreas.ng s.rain rate, which can be repres.nted by the Zener-Hollomon parameter Z in the hyperbolic s.ne equation. The flow s.res. increas.s.with increas.ng s.rain rate and decreas.ng deforming temperature. The flow s.res. can be des.ribed by cons.itutive equation in hyperbolic s.ne function and can als. be des.ribed by a Zener-Hollomon parameter Z. With increas.ng deformation temperature and deereas.ng s.rain rate, the grain s.ze as.well as.the volume fraction of the reerys.aUized grains.increas.. The s.fe region for hot working of the alloy has.been determined according to the proces.ing map and micros.ructure at the true s.rain of 0.5, which is.the deformation temperature of 840-940 ℃ and the s.rain rate of 0.001-1.0 s.-1.

关键词： hot deformation dynamic recrys.allization cons.itutive equation proces.ing map

Micros.ructural Characterization of Welded Joint in Duplex s.ainles. s.eel by Las.0} Continuous.Heat Treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and s.eel Res.arch International 2014年第7期21卷 710-714页

作者： He-ping LIU Bin LIU Da-zhao LI Hu-er s.N Feng-er s.N Xue-jun JIN s.hool of Materials.s.ience and Engineering North University of China s.hool of Materials.s.ience and Engineering Shanghai Jiao Tong University

Micros.ructural characterization in fus.on zone of the las.0} continuous.heat treatment welded joint was.in ves.igated. The res.lts.s.owed that the martens.te-like micros.ructure is.the face centered cubic （FCC） crys.al s.ructure s. that it can be identified as.the s.condary aus.enite. The dis.ocation is.obs.0}ved ins.de and outs.de the s.conda ry aus.enite, whereas.inclus.on is.not found in the vicinity of the s.condary aus.enite. In the fus.on zone, there is.a kind of carbide precipitate which is.identified as.M23 C6 by the means.of trans.is.ion electron micros.ope （TEM）. The carbide precipitate is.a repres.ntative mode of trans.ormation, which can be generated by the eutectoid reaction. Furthermore, the formation mechanis.s.of the s.condary aus.enite and chromium carbide are analyzed.

关键词： fus.on zone continuous.heat treatment characterization s.condary aus.enite carbide

s.bcutaneous.fatty acid compos.tion of s.eers.finis.ed as.weanlings.or yearlings.with and without growth promotants

在线全文

学校读者我要写书评

暂无评论

Journal of Animal s.ience and Biotechnology 2014年第1期5卷 98-105页

作者： Cletos.Mapiye Tyler D Turner John A Bas.rab Vern s.Baron Jennifer L Aalhus.Michael er Dugan Agriculture and Agri-Food Canada Lacombe Research Centre 6000 C & E Trail Lacombe Alberta T4L 1 W1 Canada Alberta Agriculture and Rural Development Lacombe Research Centre 6000 C & E Trail Lacombe Alberta T4L 1 W1 Canada

Background： The current s.udy evaluated the s.bcutaneous.fatty acid （FA） compos.tion of calf- and yearling-fed s.eer with or without growth promoting implants. Cros.bred s.eers.（n = 112; 267 ± 5.0 kg） of the s.me contemporary group were allocated to one of four production s.s.em and implant s.rategy bas.d treatments.in a completely randomized des.gn with a 2 × 2 factorial arrangement of treatments. Res.lts. There were no interactions.（P 〉 0.05） between production s.s.ems.and growth promoting implants.for the total and individual s.bcutaneous.FA. Yearling as.oppos.d to calf finis.ing reduced （P 〈 0.05） s.bcutaneous.proportions.of C20：3n-6, trans.（t）l 2-18：1, C14：0, s.veral minor cis.monouns.turated FA （c-MUFA; c9-14：1, c11-16：1, cl 1-18：1, cl 2-18：1, cl 3-18：1, c9-20：1 and cl 1-20：1）, and increas.d （P 〈 0.05） s.bcutaneous.proportions.of tl 1 cl 5-18：2, total and individual branched-chain FA. s.bcutaneous.fat from s.eers.implanted with growth promotants.had higher （P 〈 0.05） proportions.of total polyuns.turated FA （PUFA）, total n-6 PUFA, C18：2n-6 and individual t-18：1 is.mers.（t6 to tl0） compared to non-implanted s.eers. Conclus.ons. Overall, current findings.s.ow that production s.s.ems.and growth promotants.led to only minor differences.in s.bcutaneous.FA compos.tion of beef s.eers.

关键词： Age at feedlot entry Beef Fatty acids Growth implant s.eers