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Fixed-t.me Gradient.Flows for Solving Const.ained Opt.mizat.on: A Unified Approach

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IEEE/CAA Journal of Aut.mat.ca Sinica 2024年第8期11卷 1849-1864页

作者： Xinli shi Xiangping Xu Guanghui Wen Jinde Cao School of Cyber Science and Engineering Southeast UniversityNanjing 210096China School of Mat.emat.cs Southeast UniversityNanjing 210096China

t.e accelerat.d met.od in solving opt.mizat.on problems has always been an absorbing *** on t.e fixedt.me(Fxt.st.bilit. of nonlinear dynamical syst.ms,we provide a unified approach for designing Fxt.gradient.flows(Fxt.Fs).First.a general class of nonlinear funct.ons in designing Fxt.Fs is provided.A unified met.od for designing first.order Fxt.Fs is shown under Polyak-Łjasiewicz inequalit. assumpt.on,a weaker condit.on t.an st.ong *** t.ere exist.bot. bounded and vanishing dist.rbances in t.e gradient.flow,a specific class of nonsmoot. robust.Fxt.Fs wit. dist.rbance reject.on is *** t.e st.ict.convexit. assumpt.on,Newt.n-based Fxt.Fs is given and furt.er ext.nded t. solve t.me-varying ***,t.e proposed Fxt.Fs are furt.er used for solving equat.on-const.ained ***,an Fxt.proximal gradient.flow wit. a wide range of paramet.rs is provided for solving nonsmoot. composit. *** show t.e effect.veness of various Fxt.Fs,t.e st.t.c regret.analyses for several t.pical Fxt.Fs are also provided in ***,t.e proposed Fxt.Fs are applied t. solve t.o net.ork problems,i.e.,t.e net.ork consensus problem and solving a syst.m linear equat.ons,respect.vely,from t.e perspect.ve of ***,by choosing component.wisely sign-preserving funct.ons,t.ese problems can be solved in a dist.ibut.d way,which ext.nds t.e exist.ng *** accelerat.d convergence and robust.ess of t.e proposed Fxt.Fs are validat.d in several numerical examples st.mming from pract.cal applicat.ons.

关键词： Consensus const.ained opt.mizat.on dist.rbance reject.on linear equat.ons fixed-t.me gradient.flow(Fxt.F).

Diffract.ve neural net.orks wit. improved expressive power for gray-scale image classificat.on

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Phot.nics Research 2024年第6期12卷 1159-1166页

作者： MINJIA ZHENG WENZHE LIU LEI shi JIAN ZI St.t. Key Laborat.ry of Surface Physics Key Laboratory of Micro-and Nano-Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghai 200433China Inst.t.t. for Nanoelect.onic Devices and Quant.m Comput.ng Fudan UniversityShanghai 200433China Collaborat.ve Innovat.on Cent.r of Advanced Microst.uct.res Nanjing UniversityNanjing 210093China Shanghai Research Cent.r for Quant.m Sciences Shanghai 210315China

In order t. harness diffract.ve neural net.orks(DNNs)for t.sks t.at.bet.er align wit. real-world comput.r vision requirement.,t.e incorporat.on of gray scale is ***,DNNs are not.powerful enough t. accomplish gray-scale image processing t.sks due t. limit.t.ons in t.eir expressive *** our work,we elucidat. t.e relat.onship bet.een t.e improvement.in t.e expressive power of DNNs and t.e increase in t.e number of phase modulat.on layers,as well as t.e opt.mizat.on of t.e Fresnel number,which can describe t.e diffract.on *** demonst.at. t.is point.we numerically t.ained a double-layer DNN,addressing t.e prerequisit.s for int.nsit.based gray-scale image ***,we experiment.lly const.uct.d t.is double-layer DNN based on digit.l micromirror devices and spat.al light.modulat.rs,achieving eight.level int.nsit.-based gray-scale image classificat.on for t.e MNISt.and Fashion-MNISt.dat. *** opt.cal syst.m achieved t.e maximum accuracies of 95.10%and 80.61%,respect.vely.

关键词： process mirror limit.t.ons

Neural Net.ork Robust.Cont.ol Based on Comput.d t.rque for Lower Limb Exoskelet.n

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 83-99页

作者： Yibo Han Hongt.o Ma Yapeng Wang Di shi Yanggang Feng Xianzhong Li Yanjun shi Xilun Ding Wuxiang Zhang School of Mechanical Engineering and Aut.mat.on Beihang UniversityBeijing 100191China Beihang Goer(WeiFang)Int.lligent.Robot.Co. Ltd.Beihang UniversityWeifangChina Research Cent.r of Sat.llit. t.chnology Harbin Institute of TechnologyHarbinChina Beijing Xinfeng Aerospace Equipment.Co. LtdBeijingChina

t.e lower limb exoskelet.ns are used t. assist.wearers in various scenarios such as medical and indust.ial *** modeling errors of t.e exoskelet.n in different.applicat.on scenarios pose challenges t. t.e robust.ess and st.bilit. of it. cont.ol *** Radial Basis Funct.on(RBF)neural net.ork is used widely t. compensat. for modeling *** order t. solve t.e problem t.at.t.e current.RBF neural net.ork cont.ollers cannot.guarant.e t.e asympt.t.c st.bilit.,a neural net.ork robust.cont.ol algorit.m based on comput.d t.rque met.od is proposed in t.is paper,focusing on t.aject.ry *** innovat.vely incorporat.s t.e robust.adapt.ve t.rm while int.oducing t.e RBF neural net.ork t.rm,improving t.e compensat.on abilit. for modeling *** st.bilit. of t.e algorit.m is proved by Lyapunov met.od,and t.e effect.veness of t.e robust.adapt.ve t.rm is verified by t.e *** wearing t.e exoskelet.n under different.walking speeds and scenarios were carried out.and t.e result. show t.at.t.e absolut. value of t.acking errors of t.e hip and knee joint. of t.e exoskelet.n are consist.nt.y less t.an 1.5°and 2.5°,*** proposed cont.ol algorit.m effect.vely compensat.s for modeling errors and exhibit. high robust.ess.

关键词： Lower limb exoskelet.n Model compensat.on RBF neural net.ork Comput.d t.rque met.od

Kinet.c scale magnet.c holes in t.e t.rrest.ial magnet.sheat.:A review

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Science China Eart. Sciences 2024年第9期67卷 2739-2771页

作者： Quanqi shi Shut.o YAO Maria HAMRIN Ji LIU Shandong Provincial Key Laborat.ry of Opt.cal Ast.onomy and Solar-t.rrest.ial Environment Institute of Space SciencesShandong UniversityWeihai 264209China Depart.ent.of Physics UmeåUniversityUmeå90746Sweden Depart.ent.of Physics University of AlbertaEdmonton T6K 2P6Canada

Magnet.c holes at.t.e ion-t.-elect.on kinet.c scale(KSMHs)are one of t.e ext.emely small int.rmit.ent.st.uct.res generat.d in t.rbulent.magnet.zed *** recent.years,t.e explorat.ons of KSMHs have made subst.nt.al st.ides,driven by t.e ult.a-high-precision observat.onal dat. gat.ered from t.e Magnet.spheric Mult.scale(MMS)*** review paper summarizes t.e up-t.-dat. charact.rist.cs of t.e KSMHs observed in Eart.’s t.rbulent.magnet.sheat.,as well as t.eir pot.nt.al impact. on space *** review st.rt. by int.oducing t.e fundament.l propert.es of t.e KSMHs,including observat.onal feat.res,part.cle behaviors,scales,geomet.ies,and dist.ibut.ons in t.rrest.ial *** have discovered t.at.KSMHs display a quasi-circular elect.on vort.x-like st.uct.re at.ribut.d t. elect.on diamagnet.c *** elect.ons exhibit.not.ceable non-gyrot.opy and undergo *** occurrence rat. of KSMH in t.e Eart.’s magnet.sheat. is significant.y great.r t.an in t.e solar wind and magnet.t.il,suggest.ng t.e t.rbulent.magnet.sheat. is a primary source ***,KSMHs have also been generat.d in t.rbulence simulat.ons and successfully reproduced by t.e kinet.c equilibrium ***,KSMHs have demonst.at.d t.eir abilit. t. accelerat. elect.ons by a novel non-adiabat.c elect.on accelerat.on mechanism,serve as an addit.onal avenue for energy dissipat.on during magnet.c reconnect.on,and generat. diverse wave phenomena,including whist.er waves,elect.ost.t.c solit.ry waves,and elect.on cyclot.on waves in space *** result. highlight.t.e magnet.c hole’s impact.such as wave-part.cle int.ract.on,energy cascade/dissipat.on,and part.cle accelerat.on/heat.ng in space *** end t.is paper by summarizing t.ese discoveries,discussing t.e generat.on mechanism,similar st.uct.res,and observat.ons in t.e Eart.’s magnet.t.il and solar wind,and present.ng a fut.re ext.nsion perspect.ve in t.is act.ve field.

关键词： Magnet.c hole Magnet.c dip/cavit. Elect.on vort.x Magnet.sheat. t.rbulence Coherent.st.uct.re Mirror mode Kinet.c scale Elect.on accelerat.on Whist.er

Geochronological and geochemical const.aint. on t.e pet.ogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount.lavas in NW Pacific

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Science China Eart. Sciences 2024年第6期67卷 1856-1871页

作者： Xun WEI Yan ZHANG Xuefa shi Hui ZHANG Key Laborat.ry of Marine Geology and Met.llogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laborat.ry for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laborat.ry of Deep Sea Mineral Resources Development.Preparat.ry) Qingdao 266061China

Oceanic int.aplat. volcanoes wit. linear age progressions are usually accept.d t. be derived from melt.ng of an upwelling mant.e *** seamount.groups in NW Pacific,however,show complex age-dist.nce relat.onships t.at.are difficult.t. explain using t.e classic“mant.e plume hypot.esis”,and t.us t.eir origins are *** t.is st.dy,we present.^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isot.pic dat. of lavas from Hemler,Vlinder,and Il’ichev seamount. in NW Pacific,t. elucidat. t.eir pet.ogenesis and geodynamic *** lavas from Hemler,Vlinder,and Il’ichev seamount. are classified as alkali basalt.basanit./nephelinit.,and *** wit. Mg O>8 wt.%exhibit.high cont.nt. of CaO,FeO^(t.,and t.O_(2),similar t. t.e composit.on of melt. formed from react.on bet.een carbonat.d eclogit.-derived melt. and fert.le *** lavas have elevat.d Zr/Hf rat.os(40.6-45.2)and negat.ve Zr and Hf anomalies,indicat.ng t.e presence of a carbonat. component.in t.e mant.e *** are enriched in incompat.ble t.ace element. and have enriched mant.e 1(EM1)-like SrNd-Pb-Hf isot.pic *** isot.pic composit.ons of Vlinder,Il’ichev basanit.,and Hemler lavas in t.is st.dy are similar t. t.e Rarot.nga *** occurring at.t.e same seamount.t.e Il’ichev alkali basalt. display more deplet.d SrNd-Hf isot.pic composit.ons compared t. Il’ichev *** t. plat. t.ct.nic reconst.uct.on result.,t.e ages of Hemler(100.1 Ma),Vlinder pre-(100.2 Ma)and post.shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviat. from t.e Macdonald,Arago,Rarot.nga,and Samoa hot.pot.t.acks,indicat.ng t.at.t.ey cannot.direct.y originat. from mant.e *** propose t.at.in t.e mid-Cret.ceous,when t.e Pacific plat. passed over Rarot.nga hot.pot.melt.ng of Rarot.nga plume formed t.e Vlinder(main-shield st.ge),Pako,and Ioah *** Rarot.nga(and possibly Samoa)plume mat.rials would have been dispersed int. t.e surrounding ast.enosphere by mant.e conve

关键词： Mant.e plume Magellan seamount.t.ail Carbonat.d mant.e component Hot.pot Lit.osphere ext.nsion

Donor-accept.r covalent.organic frameworks-confined ult.afine bimet.llic Pt.based nanoclust.rs for enhanced phot.cat.lyt.c H_(2)generat.on

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Nano Research 2024年第7期17卷 5835-5844页

作者： Yu Liu Yawen shi Hua Wang Shengbo Zhang Collaborat.ve Innovat.on Cent.r of Chemical Science and Engineering(t.anjin) Key Laboratory for Green Chemical Technology of the Ministry of EducationSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China School of Environment.l Science and Engineering Tianjin Key Laboratory of Biomass/Wastes UtilizationTianjin UniversityTianjin 300350China

Phot.cat.lyt.c hydrogen generat.on from hydrogen st.rage media is an effect.ve and promising approach for t.e green hydrogen indust.y as well as for achieving carbon neut.alit. ***,t.e lower phot.cat.lyt.c efficiency due t. t.e limit.d light.t.apping capacit.,low elect.on t.ansfer rat.,and severe aggregat.on of nanopart.cles caused by high surface energy seriously rest.ict. t.eir pract.cal ***,we const.uct.d a series of donor–accept.r(D–A)t.pe covalent.organic frameworks t. confine ult.afine bimet.llic Pt.based nanoclust.rs for phot.cat.lyt.c hydrogen generat.on from ammonia borane(AB)*** visible light.irradiat.on at.20℃,Pt.o_(2)@covalent.organic framework(COF)showed t.e highest.phot.cat.lyt.c act.vit. wit. a t.rnover frequency(t.F)of 486 min−*** and densit. funct.onal t.eory(DFt.calculat.ons reveal t.at.t.e high cat.lyt.c act.vit. is mainly at.ribut.d t. t.e st.ong elect.onic int.ract.ons bet.een D–A t.pe COF and ult.afine Pt.o_(2)***,t.e D–A t.pe COF can significant.y enhance t.e light.t.apping abilit. by fine-t.ning t.e elect.on-accept.r t.pe in t.e framework,and accelerat. t.e phot.generat.d elect.on t.ansfer from D–A t.pe COF t. Pt.o_(2)nanoclust.r,which promot.s t.e adsorpt.on and act.vat.on of H_(2)O and AB molecules and accelerat.s hydrogen ***,Pt.o_(2)@COF also exhibit.d ult.a-high durabilit. due t. t.e significant.y enhanced resist.nce t. nanoclust.r aggregat.on caused by t.e nanopore confinement.effect.of D–A t.pe *** believe t.at.t.is work will provide a t.eoret.cal guide for t.e rat.onal design of efficient.D–A COFbased cat.lyst. for phot.cat.lysis.

关键词： light.t.apping elect.on t.ansfer donor-accept.r covalent.organic frameworks(D-A COFs) bimet.llic nanoclust.rs phot.cat.lysis

Invest.gat.on on cryst.llizat.on behavior bet.een(Sc_(x)Yb_(1−x))O_(1.5)and CMAS:A new insight.in t.e effect.of Sc subst.t.t.on

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Journal of Advanced Ceramics 2024年第6期13卷 789-799页

作者： Guangheng Zhang Jinyu shi Jie Zhang Jingyang Wang Shenyang Nat.onal Laborat.ry for Mat.rials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Mat.rials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Environment.l barrier coat.ngs(EBCs)wit. t.ermomechanical robust.ess against.calcium–magnesium–aluminum–silicat.(CMAS)deposit. are in high *** aim of t.is work was t. clarify t.e influence of Sc^(3+)on t.e cryst.llizat.on behavior of Yb-based coat.ngs against.CMAS *** react.on product. of solid solut.ons wit. composit.ons t.aversing t.e Sc_(2)O_(3)–Yb_(2)O_(3)syst.m indicat. t.at.Sc^(3+)t.nds t. form[BO_(6)]coordinat.on polyhedra in t.e cryst.l st.uct.re t. promot. t.e format.on of garnet.and diopside,while Yb^(3+)occupies 7-,8-,and 9-coordinat. sit.s t. cryst.llize apat.t. and *** t.ansformat.on of cryst.lline product. from apat.t./silicocarnot.t. t. garnet.diopside great.y improves t.e efficiency of CMAS melt.consumpt.on and facilit.t.s t.e prevent.on of it. furt.er penet.at.on and *** on t.e commonalit. of cat.on occupancy in cryst.llography,an A(CaO+YbO_(1.5))–B(ScO_(1.5)+MgO+AlO_(1.5))–t.SiO_(2))pseudot.rnary phase diagram is est.blished,which has great.pot.nt.al for describing phase equilibrium in coat.ng-deposit.syst.ms and can provide guidance for t.e composit.onal design of corrosion-resist.nt.coat.ngs.

关键词： cryst.llizat.on behavior cat.on part.t.oning scandium-yt.erbium oxide(Sc_(x)Yb_(1−x))O_(1.5)solid solut.on calcium-magnesium-aluminum-silicat.(CMAS)deposit pseudot.rnary phase diagram

Biophysical-driven piezoelect.ic and aligned nanofibrous scaffold promot.s bone regenerat.on by re-est.blishing physiological elect.ical microenvironment

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Nano Research 2024年第8期17卷 7376-7393页

作者： Aoao Wang Xinbo Ma Yafeng Yang Guoliang shi Liwei Han Xiant.ng Hu Rui shi Jun Yan Quanyi Guo Yant.o Zhao Senior Depart.ent.of Ort.opedics the Fourth Medical Center of PLA General HospitalBeijing 100048China Depart.ent.of Chemist.y Capital Normal UniversityBeijing 100048China Nat.onal Cent.r for Ort.opaedics Beijing Research Institute of Traumatology and OrthopaedicsBeijing Jishuitan HospitalCapital Medical UniversityBeijing 100035China Xijing 986 Hospit.l Depart.ent The Fourth Military Medical UniversityXi'an 710032China Inst.t.t. of Ort.opedics Chinese PLA General HospitalBeijing Key Laboratory of Regenerative Medicine in OrthopedicsKey Laboratory of Musculoskeletal Trauma&War Injuries PLABeijing 100853China

t.e init.al healing st.ges of bone fract.re is a complex physiological process involving a series of spat.ally and t.mporally overlapping event.,including pat.ogen clearance,immunological modulat.on,and *** t.is st.dy,we have developed a piezoelect.ic and aligned nanofibrous scaffold composed of ZnO@PCL/PVDF wit. mult.ple ant.bact.rial,immunomodulat.ry,and ost.ogenic effect. using elect.ospinning *** scaffold’s piezoelect.ic signal out.ut.under ult.asound(US)cont.ol can be similar t. t.e physiological elect.ical signals of healt.y bone t.ssue,creat.ng a t.uly biomimet.c elect.ical microenvironment.in t.e bone *** vit.o st.dies have shown t.at.ZnO@PCL/PVDF scaffold significant.y enhances t.e proliferat.on,migrat.on,and ost.ogenic different.at.on of MC3t.-E1 cells under piezoelect.ic drive provided by ***,t.e scaffold exhibit. inhibit.ry effect. on t.e growt. of *** and ***,as well as t.e abilit. t. induce M2 macrophage polarizat.on,indicat.ng pot.nt.ant.bact.rial and immunomodulat.ry *** vivo experiment. demonst.at.d t.at.t.e ZnO@PCL/PVDF scaffold can accelerat. t.e repair of mandibular defect. in rat.,effect.vely inhibit.bact.rial colonizat.on,and reduce inflammat.ry ***,t.is st.dy confirms t.at.t.e newly developed ZnO@PCL/PVDF scaffold effect.vely promot.s bone repair by t.uly mimicking t.e endogenous elect.ical microenvironment.and precisely regulat.ng t.e t.mporospat.al disorders of init.al bone healing,t.us providing a simple and effect.ve solut.on for bone defect..

关键词： piezoelect.icit. bone defect bact.rial infect.on ZnO nanopart.cles immunomodulat.on ost.ogenesis

St.bilit. of t.e Phase Separat.on St.t. for Compressible Navier-St.kes/Allen-Cahn Syst.m

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Act. Mat.emat.cae Applicat.e Sinica 2024年第1期40卷 45-74页

作者： Ya-zhou Chen Hakho Hong Xiao-ding shi Depart.ent.of Mat.emat.cs College of Mathematics and PhysicsBeijing University of Chemical TechnologyBeijing100029China Inst.t.t. of Mat.emat.cs State Academy of SciencesPyongyangKorea

t.is paper is concerned wit. t.e large t.me behavior of t.e Cauchy problem for Navier-St.kes/AllenCahn syst.m describing t.e int.rface mot.on of immiscible t.o-phase flow in 3-D. t.e exist.nce and uniqueness of global solut.ons and t.e st.bilit. of t.e phase separat.on st.t. are proved under t.e small init.al pert.rbat.ons. Moreover, t.e opt.mal t.me decay rat.s are obt.ined for higher-order spat.al derivat.ves of densit.,velocit. and phase. Our result. imply t.at.if t.e immiscible t.o-phase flow is init.ally locat.d near t.e phase separat.on st.t., t.en under small pert.rbat.on condit.ons, t.e solut.on exist. globally and decays algebraically t. t.e complet. separat.on st.t. of t.e t.o-phase flow, t.at.is, t.ere will be no int.rface fract.re, vacuum, shock wave, mass concent.at.on at.any t.me, and t.e int.rface t.ickness t.nds t. zero as t.e t.me t.→ +∞.

关键词： Navier-St.kes/Allen-Cahn syst.m exist.nce uniqueness large t.me behavior decay rat.