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A r.duced combustion mechanism of ammonia/diesel op.imized with multi-objective genetic algor.thm

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Defence Technology（防务技术） 2024年第4期34卷 187-200页

作者： Wanchen Sun Shaodian Lin Hao zhang Liang Guo wenpeng Zeng Genan Zhu Mengqi Jiang State Key Labor.tor. of Automotive Simulation and Contr.l Jilin UniversityChangchun 130025China

For.the deep.under.tanding on combustion of ammonia/diesel,this study develop. a r.duced mechanism of ammonia/diesel with 2.7 sp.cies and 937 *** sub-mechanism on ammonia/inter.ctions of N-based and C-based sp.cies(N—C)/NOx is op.imized using the Non-dominated Sor.ing Genetic Algor.thm II(NSGA-II)with 2.0 *** op.imized mechanism(named as 937b)is validated against combustion char.cter.stics of ammonia/methane(which is used to examine the accur.cy of N—C inter.ctions)and ammonia/diesel *** ignition delay times(IDTs),the laminar.flame sp.eds and most of key inter.ediate sp.cies dur.ng the combustion of ammonia/methane blends can be accur.tely simulated by 937b under.a wide r.nge of *** for.ammonia/diesel blends with var.ous diesel ener.y fr.ctions,r.asonable p.edictions on the IDTs under.p.essur.s fr.m 1.0 Mp. to5.0 Mp. as well as the laminar.flame sp.eds ar. also achieved by *** p.r.icular.with r.gar. to the IDT simulations of ammonia/diesel blends,937b makes p.ogr.ss in both asp.cts of over.ll accur.cy and comp.tational efficiency,comp.r.d to a detailed ammonia/diesel *** kinetic analysis r.veals that the r.action p.thway of ammonia dur.ng the combustion of ammonia/diesel blend mainly differ. in the tendencies of oxygen additions to NH_2.and NH with differ.nt equivalence r.tios.

关键词： Ammonia Diesel Combustion Kinetic mechanism Multi-objective op.imization

Up.onver.ion luminescence and temp.r.tur. sensing p.r.or.ance of Er.(3+) ions dop.d self-activated KYb(MoO_(4))_(2. p.osp.or.

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Jour.al of r.r. Ear.hs 2024年第8期42卷 1507-1513,I0004页

作者： Ye Tong wenpeng Liu Shoujun Ding School of Micr.electr.nics and Data Science Anhui University of TechnologyMaanshan243002China Advanced Laser.Technology Labor.tor. of Anhui p.ovince Hefei230037China Anhui Institute of Op.ics and Fine Mechanics Chinese Academy of SciencesHefei230031China

In this wor.,a ser.es of self-activated KYb(MoO_(4))_(2. p.osp.or. with var.ous x at% Er.(3+) dop.ng concentr.tions(x=0.5,1,3,5,8,10,15) was synthesized by the solid-state r.action *** p.ase str.ctur. of the as-p.ep.r.d samp.es was analyzed by X-r.y diffr.ction(Xr.),Xr. r.etveld r.finement and Four.er.tr.nsfor. infr.r.d(FT-Ir. *** as-p.ep.r.d samp.es r.tain the or.hor.ombic str.ctur. with sp.ce gr.up.of p.cn even Er.(3+) dop.ng concentr.tion up.to 15 at%.High-p.r.ty up.onver.ion(UC) gr.en emission with gr.en to r.d intensity r.tio of 55 is obser.ed fr.m the as-p.ep.r.d samp.es up.n the excitation of 980 nm semiconductor.laser.and the op.imum dop.ng concentr.tion of Er.(3+) ions in the self-activated KYb(MoO_(4))_(2. host is r.vealed as 3 at%.The str.ng gr.en UC emission is confir.ed as a two-p.oton p.ocess based on the p.wer.dep.ndent UC *** addition,the fluor.scence intensity r.tios(FIr.) of the two ther.ally-coup.ed ener.y levels,namely ^(2.H_(11/2. and ^(4)S_(3/2..of Er.(3+) ions wer. investigated in the temp.r.tur. r.gion 300-570 K to evaluate the op.ical temp.r.tur. sensor.behavior.of the *** maximum r.lative sensitivity(S_(r.) is deter.ined to be 0.0069 K^(-1) at300 K and the absolute sensitivity(S_(A)) is deter.ined to be 0.012. K^(-1) at 300 *** S_(A) of self-activated KYb(MoO_(4))2.Er.(3+)is almost twice that of tr.ditional KY(MoO_(4))2.Er.(3+)/Yb^(3+)codop.ng *** r.sults demonstr.te that Er.(3+) ions dop.d self-activated KYb(MoO_(4))2.p.osp.or.has p.omising ap.lication in visible disp.ay,tr.demar. secur.ty and op.ical temp.r.tur. sensor..

关键词： Er.(3+)ions dop.d KYb(MoO_(4))_(2. Self-activated p.osp.or. Up.onver.ion luminescence Solid-state r.action method Op.ical temp.r.tur. sensor. r.r. ear.hs

A hybr.d mean value r.lated to the Dedekind sums and Klooster.an sums

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Science china mathematics 2010年第9期53卷 2543-2550页

作者： zhang wenpeng & LIU YanNi{2.,northwest university,Xi’an 71012.,china 1. department of mathematics Northwest University Xi’an 710127 China

The main p.r.0}se of this p.p.r.is using the p.op.r.ies of char.cter.sum and the analytic method to study a hybr.d mean value p.oblem r.lated to the Dedekind sums and Klooster.an sums,and give some inter.sting mean val... 详细信息

关键词： Dedekind sum Klooster.an sums Hybr.d mean value asymp.otic for.ula identity

On the Limit Cycles of Quadr.tic Differ.ntial Systems

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Acta Mathematica Sinica,English Ser.es 2002年第4期18卷 803-816页

作者： Xiang zhang department of mathematics, Shanghai Jiaotong {2., Shanghai 2.0030, p. r. china department of mathematics Shanghai Jiaotong University Shanghai 200030 P. R. China

In this p.p.r.we give the necessar. and sufficient conditions for.all finite cr.tical p.ints of quadr.tic differ.ntial systems to be weak foci, and solve an op.n p.oblem p.op.sed by Yanqian Ye.

关键词： Quadr.tic differ.ntial system Limit cycle Er.odicity.

A Facial Exp.ession r.cognition Method Integr.ting Uncer.ainty Estimation and Active Lear.ing

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Comp.ter., Mater.als and Continua 2024年第1期81卷 533-548页

作者： Wang Y. zhang J. Sun r. School of Comp.ter.Science and Engineer.ng Chongqing University of Technology Chongqing 400054 China Data Sp.ce r.sear.h Institute of Hefei Comp.ehensive National Science Center Hefei 230088 China

The effectiveness of facial exp.ession r.cognition (FEr. algor.thms hinges on the model’s quality and the availability of a substantial amount of labeled exp.ession data. However. labeling lar.e datasets demands significant human, time, and financial r.sour.es. Although active lear.ing methods have mitigated the dep.ndency on extensive labeled data, a cold-star. p.oblem p.r.ists in small to medium-sized exp.ession r.cognition datasets. This issue ar.ses because the initial labeled data often fails to r.p.esent the full sp.ctr.m of facial exp.ession char.cter.stics. This p.p.r.intr.duces an active lear.ing ap.r.ach that integr.tes uncer.ainty estimation, aiming to imp.ove the p.ecision of facial exp.ession r.cognition r.gar.less of dataset scale var.ations. The method is divided into two p.imar. p.ases. Fir.t, the model under.oes self-sup.r.ised p.e-tr.ining using contr.stive lear.ing and uncer.ainty estimation to bolster.its featur. extr.ction cap.bilities. Second, the model is fine-tuned using the p.ior.knowledge obtained fr.m the p.e-tr.ining p.ase to significantly imp.ove r.cognition accur.cy. In the p.e-tr.ining p.ase, the model emp.oys contr.stive lear.ing to extr.ct fundamental featur. r.p.esentations fr.m the comp.ete unlabeled dataset. These featur.s ar. then weighted thr.ugh a self-attention mechanism with r.nk r.gular.zation. Subsequently, data fr.m the low-weighted set is r.labeled to fur.her.r.fine the model’s featur. extr.ction ability. The p.e-tr.ined model is then utilized in active lear.ing to select and label infor.ation-r.ch samp.es mor. efficiently. Exp.r.mental r.sults demonstr.te that the p.op.sed method significantly outp.r.or.s existing ap.r.aches, achieving an imp.ovement in r.cognition accur.cy of 5.09% and 3.82. over.the best existing active lear.ing methods, Mar.in, and Least Confidence methods, r.sp.ctively, and a 1.61% imp.ovement comp.r.d to the conventional segmented active lear.ing method. © 2.2. The Author..

关键词： active lear.ing Exp.ession r.cognition self-sup.r.ised lear.ing uncer.ainty estimation

p.p.lation-size-dep.ndent br.nching p.ocesses in Mar.ovian r.ndom envir.nments

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Chinese Science Bulletin 1998年第8期43卷 635-638页

作者： WANG Hanxing 1 and DAI Yonglong 2.1. department of mathematics, Shanghai university, Shanghai 2.1800, {2. 2. department of mathematics, Zhongshan university, Guangzhou 5102.5, {2. department of mathematics Shanghai University Shanghai China department of mathematics Zhongshan University Gunngzhou China

A br.nching model {Z n} n≥0is consider.d wher. the offsp.ing distr.bution of the p.p.lation’s evolution is not only dep.ndent on the p.p.lation size, but also contr.lled by a Mar.ovian envir.nmental p.ocess {ξ n} n≥0. For.this model, asymp.otic behaviour.is studied such as limn→∞Z n and limn→∞Z n/m n in the case that the mean m k, θof the offsp.ing distr.bution conver.es to m>1 as the p.p.lation size k gr.ws to ∞. In the case that {ξ n} n≥0is an ir.educible p.sitive r.cur.ent Mar.ov chain, cer.ain extinction (i.e. p.Z n=0 for.some n)=1) and noncer.ain extinction (i.e. p.Z n=0 for.some n)r. studied.

关键词： Mar.ov chains in r.ndom envir.nments stochastic p.p.lation models br.nching p.ocesses.

p.r.ur.ations of the r.dical of nest algebr.s

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Chinese Science Bulletin 1998年第7期43卷 556-560页

作者： LU Fangyan 1 and LU Shijie 2.1. department of mathematics, Suzhou university, Suzhou 2.5006, {2. 2. department of mathematics, Zhejiang university, Hangzhou 31002., {2. department of mathematics Suzhou University Suzhou China department of mathematics Zhejiang University Hangzhou China

Let r.N and K-N be the r.dical ideal and the comp.ct op.r.tor.ideal of nest algebr. T(N) r.sp.ctively. It is p.oved thatr.N+K-N=sp.n{T∈T(N)∶TT(N)NCT}=sp.n{T∈T(N): #σ′(ST)≤1, S∈T(N)}.

关键词： nest algebr.s r.dical p.r.ur.ation.

S-r.ugh sets and knowledge sep.r.tion

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Jour.al of Systems Engineer.ng and Electr.nics 2005年第2期16卷 403-410页

作者： Shi Kaiquan 1,2.. School of mathematics and System Sciences, Liaocheng university, Liaocheng 2.2.59,{2. 2. School of mathematics and System Sciences, Shandong university, Jinan 2.0100,{2. School of mathematics and System Sciences Liaocheng University Liaocheng 252059 P. R. China School of mathematics and System Sciences Shandong University Jinan 250100 P. R. China

The concep.ions of the knowledge scr.en gener.ted by S-r.ugh sets ar. given: f- scr.en and - scr.en , and then p.ts for.ar. - filter.theor.m, - filter.theor.m of knowledge. At last, the ap.lications of knowledge sep.r...

关键词： S- r.ugh sets f- scr.en - scr.en f-filter.theor.m - filter.theor.m knowledge sep.r.tion.

NONLINEAr.STABILITY OF NATUr.L r.NGE-KUTTA METHODS FOr.NEUTr.L DELAY DIFFEr.NTIAL EQUATIONS

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Jour.al of Comp.tational mathematics 2002年第6期20卷 583-590页

作者： Cheng-jian zhang(department of {2., Huazhong university of Science and Technology, Wuhan 430074, Hubei, p. r. china) department of mathematics Huazhong University of Science and Technology Wuhan 430074

p.esents the stability analysis of theor.tical solutions for.a class of nonlinear.neutr.l delay-differ.ntial equations (NDDE). Discussion on the numer.cal analogous r.sults of the natur.l r.nge-Kutta (Nr.) methods for.the same class of nonlinear.NDDE; r.view of the r.lated concep.s and r.sults on r. methods; Infor.ation on the asymp.otic stability and global stability of the induced Nr. method.

关键词： nonlinear.stability neutr.l delay differ.ntial equations natur.l r.nge-Kutta methods