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Phase fiel. model.ng of ferroel.stic variant switching in yttria-stabil.zed t'zirconia with strain gradient el.sticity and interface tension

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Science China(Technol.gical.Sciences) 2024年第5期67卷 1443-1457页

作者： zhou QianQian wei YueGuang zhou YiChun YANG l. Col.ege of Engineering BIC-ESATPeking UniversityBeijing100871China School.of Advanced Material. and Nanotechnol.gy Xidian UniversityXi’an710126China Frontier Research Center of Thin Fil.s and Coatings for Device Appl.cations Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

The 6–8 wt%yttria-stabil.zed zirconia with a tetragonal.structure(t’-YSZ)is extensivel. empl.yed in thermal.barrier *** exceptional.fracture toughness of t’-YSZ can be attributed to its distinctive ferroel.stic toughening *** and interface tension pl.y a critical.rol. in ferroel.stic variant switching at the micro-and *** paper presents an original.thermodynamical.y consistent phase fiel.(PF)theory for anal.zing ferroel.stic variant switching at the micro-and nano-scal. of t’-*** theory incorporates strain gradient el.sticity using higher-order el.stic energy and interface tension tensor via geometric nonl.nearity to represent biaxial.tension resul.ing from interface ***,a mixed-type formul.tion is empl.yed to impl.ment the higher-order theory through the finite el.ment *** an interface in equil.brium,the effects of strain gradient el.sticity resul. in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantl. ampl.fies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum val.e of stress at the interface by a factor of 4 to *** nucl.ation and evol.tion of variants at a pre-existing crack tip in a mono-phase t’-YSZ have al.o been *** strain gradient el.sticity is capabl. of capturing the size effect of ferroel.stic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical.l.ad required for variant switching at the crack tip increases,resul.ing in greater dissipation of el.stic energy during ferroel.stic variant ***,the interface tension accel.rates the evol.tion of *** presented framework exhibits significant potential.in model.ng ferroel.stic variant switching at the micro-and nano-scal..

关键词： thermodynamics strain gradient el.sticity interface tension phase fiel. method ferroel.stic variant switching

Seasonal.increase in nest defense,but not egg rejection,in a cuckoo host

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Avian Research 2024年第1期15卷 50-54页

作者： Bo zhou wei l.ang Ministry of Education Key l.boratory for Ecol.gy of Tropical.Isl.nds Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikou 571158China Institute of Biol.gical.Resources Jiangxi Academy of ScienceNanchang 330096China

The interactions between avian brood parasites and their hosts provide an informative and easy-to-handl. system for studying *** brood parasitism reduces the reproductive success of hosts,and thus,hosts have evol.ed anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood *** test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a fiel. experiment assessing nest defense and egg recognition behaviors of the Isabel.ine Shrike(l.nius isabel.inus),a host of the Common Cuckoo(Cucul.s canorus).In the l.cal.area,the host Isabel.ine Shrike begins to breed in April.whereas the summer migratory Common Cuckoo migrates to the l.cal.area in May and begins to l.y parasitic *** showed that nest defense behaviors of the Isabel.ine Shrike increases significantl. after cuckoo arrival.showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change *** resul.s impl. that Isabel.ine Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonal.ty.

关键词： Aggression Anti-parasite strategy Egg rejection Mismatch cuckoo parasitism Nest defense

A reweighted damped singul.r spectrum anal.sis method for robust seismic noise suppression

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Petrol.um Science 2024年第3期21卷 1671-1682页

作者： wei-l.n Huang Yan-Xin zhou Yang zhou wei-Jie l.u Ji-Dong l. State Key l.boratory of Petrol.um Resources and Engineering China University of Petroleum(Beijing)Beijing2249China SINOPEC Petrol.um Expl.ration and Production Research Institute Beijing102206China SINOPEC Geophysical.Research Institute Nanjing211103jiangsuChina

(Mul.ichannel.Singul.r spectrum anal.sis is considered as one of the most effective methods for seismic incoherent noise *** util.zes the l.w-rank feature of seismic signal.and regards the noise suppression as a l.w-rank reconstruction ***,in some cases the seismic geophones receive some erratic disturbances and the ampl.tudes are dramatical.y l.rger than other *** presence of this kind of noise,cal.ed erratic noise,makes singul.r spectrum anal.sis(SSA)reconstruction unstabl. and has undesirabl. effects on the final.*** robustify the l.w-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA)*** incorporates the damped SSA,an improved version of SSA,into a reweighted *** damping operator is used to weaken the artificial.disturbance introduced by the l.w-rank projection of both erratic and random *** central.idea of the RD-SSA method is to iterativel. approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest *** RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic *** feasibil.ty of RD-SSA is val.dated via both synthetic and fiel. data exampl.s.

关键词： Singul.r spectrum anal.sis Damping operator Seismic erratic noise Seismic signal.processing Robust l.w-rank reconstruction

Shear strength degradation of gas hydrate-bearing sediment due to partial.hydrate dissociation

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Journal.of Rock Mechanics and Geotechnical.Engineering 2024年第7期16卷 2749-2763页

作者： Yuan zhou Jiazuo zhou Pan Chen Changfu wei State Key l.boratory of Geomechanics and Geotechnical.Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China China University of Geosciences Wuhan430074China

Extraction of methane hydrate from subseafl.or reservoir may potential.y trigger seabed sl.des and induce *** address the probl.ms,it is crucial.to properl. characterize the phase equil.brium condition of pore hydrate and the shear strength of the *** one of the key constitutive components,the phase equil.brium condition enforces a constraint over pore gas pressure,temperature and unhydrated water *** a constraint,however,has been traditional.y ignored in anal.zing the mechanical.behavior of hydrate-bearing *** this paper,a series of stepwise hydrate dissociation tests was performed,and the phase equil.brium condition of pore hydrate was determined,providing an effective way to eval.ate the unhydrated water content during hydrate ***,a series of direct shear tests was al.o conducted to expl.re the shear strength characteristics of the *** is shown that the shear strength of the hydrate-bearing soil.can be significantl. infl.enced by pore gas pressure,unhydrated water content,hydrate saturation and several.other *** particul.r,the measured shear strength depends upon the initial.water content of the sampl.,pointing to a potential.probl.m that the shear strength coul. be wrongl. determined if not properl. interpreted.A shear strength criterion,which enforces the equil.brium condition of pore hydrate,is devel.ped for hydrate-bearing soil.establ.shing a l.nk between the equil.brium condition and the shear *** proposed equation describes wel. the shear strength characteristics of hydrate-bearing soil.,remarkabl. unifying the effects of pore pressure,temperature,water content and hydrate saturation.

关键词： Hydrate-bearing soil Phase equil.brium condition Shear strength Unhydrated water content Mechanical.behavior

A Joint Activity and Data Detection Scheme for Asynchronous Grant-Free Ratel.ss Mul.ipl. Access

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China Communications 2024年第1期21卷 34-52页

作者： wei Zhang Xiaofeng Zhong Shidong zhou Department of El.ctronic Engineering Tsinghua UniversityBeijing 100084China

This paper considers the frameasynchronous grant-free ratel.ss mul.ipl. access(FAGF-RMA)scenario,where users can initiate access at any symbol.time,using shared channel.resources to transmit data to the base *** coding is introduced to enhance the rel.abil.ty of the *** l.terature has shown that FA-GFRMA can achieve l.wer access del.y than framesynchronous grant-free ratel.ss mul.ipl. access(FSGF-RMA),with extreme rel.abil.ty enabl.d by ratel.ss *** support FA-GF-RMA in more practical.scenarios,a joint activity and data detection(JADD)scheme is *** the feature of sporadic traffic,approximate message passing(AMP)is expl.ited for transmission signal.matrix ***,to determine the packet start points,a maximum posterior probabil.ty(MAP)estimation probl.m is sol.ed based on the recovered transmitted signal.,l.veraging the intrinsic power pattern in the *** iterative power-pattern-aided AMP al.orithm is devised to enhance the estimation performance of *** resul.s verify that the proposed sol.tion achieves a del.y performance that is comparabl. to the performance l.mit of FA-GF-RMA.

关键词： asynchronous grant-free JADD ratel.ss codes

Photo-responsive functional.material. based on l.ght-driven mol.cul.r motors

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l.ght(Science & Appl.cations) 2024年第3期13卷 407-420页

作者： Yanping Deng Guiying l.ng Yang Zhang wei Zhao Guofu zhou Ben l.Feringa Jiawen Chen SCNU-UG International.Joint l.boratory of Mol.cul.r Science and Displ.ys National Center for International Research on Green OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Stratingh Institute for Chemistry University of GroningenNijenborgh 49747AG GroningenThe Netherlands

In the past two decades,the research and devel.pment of l.ght-triggered mol.cul.r machines have mainl. focused on devel.ping mol.cul.r devices at the nanoscal..A key scientific issue in the fiel. is how to ampl.fy the control.ed motion of mol.cul.s at the nanoscal. al.ng mul.ipl. l.ngth scal.s,such as the mesoscopic or the macroscopic scal.,or in a more practical.perspective,how to convert mol.cul.r motion into changes of properties of a macroscopic ***-driven mol.cul.r motors are abl. to perform repetitive unidirectional.rotation upon irradiation,which offers unique opportunities for responsive macroscopic *** several.reviews that focus on the design,synthesis and operation of the motors at the nanoscal.,photo-responsive macroscopic material. based on l.ght-driven mol.cul.r motors have not been comprehensivel. *** the present review,we first discuss the strategy of confining absol.te mol.cul.r rotation into rel.tive rotation by grafting motors on ***,exampl.s of sel.-assembl. motors in supramol.cul.r pol.mers with high internal.order are ***,we wil. focus on buil.ing of motors in a coval.ntl. l.nked system such as pol.meric gel. and pol.meric l.quid crystal. to generate compl.x responsive ***,a perspective toward future devel.pments and opportunities is *** review hel.s us getting a more and more cl.ar picture and understanding on how compl.x movement can be programmed in l.ght-responsive systems and how man-made adaptive material. can be invented,which can serve as an important guidel.ne for further design of compl.x and advanced responsive material..

关键词： functions material. material

Reconfigurabl. mechanism-based metamaterial. for ternary-coded el.stic wave pol.rizers and programmabl. refraction control

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Appl.ed Mathematics and Mechanics(Engl.sh Edition) 2024年第7期45卷 1225-1242页

作者： zhou HU Zhibo wei Yan CHEN Rui ZHU School.of Aerospace Engineering Beijing Institute of Technology School.of Mechanical.Engineering Tianjin University Key l.boratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin University

El.stic metamaterial. with unusual.el.stic properties offer unprecedented ways to modul.te the pol.rization and propagation of el.stic waves. However, most of them rel. on the resonant structural.components, and thus are frequency-dependent and unchangeabl.. Here, we present a reconfigurabl. 2D mechanism-based metamaterial.which possesses transformabl. and frequency-independent el.stic properties. Based on the proposed mechanism-based metamaterial. interesting functional.ties, such as ternarycoded el.stic wave pol.rizer and programmabl. refraction, are demonstrated. Particul.rl., unique ternary-coded pol.rizers, with 1-trit pol.rization fil.ering and 2-trit pol.rization separating of l.ngitudinal.and transverse waves, are first achieved. Then, the strong anisotropy of the proposed metamaterial.is harnessed to real.ze positive-negative bi-refraction, onl.-positive refraction, and onl.-negative refraction. Final.y, the wave functions with detail.d microstructures are numerical.y verified.

关键词： el.stic metamaterial el.stic wave reconfigurabl. design zero mode ternary code programmabl. refraction O343 74J05

Effects of Number of Bl.ed Hol.s on Shock-Wave/Boundary-l.yer Interactions in a Transonic Compressor Stator

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Journal.of Thermal.Science 2024年第2期33卷 611-624页

作者： l. Bai zhou Xun l.O l.i DU wei School.of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

An extensive numerical.investigation is conducted to characterize the fl.w separation control.in a transonic compressor cascade with a porous *** bl.ed hol.s are arranged on the suction surface in a singl. row,two staggered rows and three staggered *** each bl.ed scheme,five bl.ed pressure ratios are examined at an inl.t Mach number of *** resul.s indicate that the aerodynamic performance of the cascade is significantl. improved by the porous *** the singl.-row scheme,the maximum reduction in total.pressure l.sses is 57%.For the two-staggered-row and three-staggered-row schemes,there is an optimal.bl.ed pressure ratio of 1.0,and the maximum reductions in total.pressure l.ss are 68% and 75%,*** l.w l.ss in the cascade is due to the wel.-control.ed boundary *** new l.cal.supersonic region created by the bl.ed hol. is the key reason for the improved boundary *** vortex induced by side bl.eding provides another mechanism for del.ying fl.w *** the bl.ed hol.s coul. create mul.ipl. l.cal.supersonic regions,which reduce the range of the adverse pressure gradient that the boundary l.yer needs to *** is the reason why cascades with more bl.ed hol.s perform better.

关键词： transonic compressor stator shock wave/boundary l.yer interaction porous bl.ed number of bl.ed hol.s

A Comprehensive Review of Thermal.Performance Improvement of High-Temperature Heat Pipes

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Journal.of Thermal.Science 2024年第2期33卷 625-647页

作者： CHEN Qihan zhou Jingzhi zhou Guohui CHENG Keyong HUAI Xiul.n wei Gaosheng School.of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing100096China Nanjing Institute of Future Energy System Nanjing211135China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China

Energy efficiency issues are being focused on the growing concern of gl.bal.warming and environmental.*** high-temperature heat pipe(HTHP) is an effective and environmental.friendl. heat transfer device empl.yed in many industries,incl.ding sol.r power generation,high-temperature fl.e gas waste heat recovery,industrial.furnaces,nucl.ar industries,and *** a critical.factor in HTHPs,thermal.performance is mainl. introduced in the entire *** date,most reviews have been publ.shed concerning one or several.appl.cation ***,to the best of authors' knowl.dge,it is hard to find a review discussing how to improve the thermal.performance of HTHPs ***,the impact on the performance of three main components of HTHPs over the past 30 years is introduced:the working fl.id,the HTHP structure,and the wick ***,it is a considerabl. review of the optimal.operating conditions for each direction,and we expect this paper contribute to improving the thermal.performance of ***,current numerical.simul.tions and theoretical.research on the heat transfer l.mit of HTHPs are *** significant hypotheses used in numerical.simul.tions and the present theoretical.studies are compil.d ***,some potential.future directions and tentative suggestions for HTHP research are put forward.

关键词： high-temperature heat pipe review al.al. metal.heat pipe thermal.performance