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Generation of mil.ijoul.-l.vel.sub-5 fs viol.t l.ser pul.es

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High Power l.ser Science and Engineering 2024年第2期12卷 33-40页

作者： Xinhua Xie Yi Hung Yunpei Deng Adrian l.Caval.eri Andrius Bal.uška Steven l.Johnson SwissFEl Paul Scherrer InstituteVilligen PSISwitzerland Photonics Institute Technische Universität WienViennaAustria Institute of Appl.ed Physics University of BernBernSwitzerland Institute for Quantum El.ctronics Physics DepartmentETH ZurichZurichSwitzerland

We demonstrate the generation,spectral.broadening and post-compression of second harmonic pul.es using a thin beta barium borate(BBO)crystal.on a fused-sil.ca substrate as the nonl.near interaction *** combining second harmonic generation in the BBO crystal.with sel.-phase modul.tion in the fused-sil.ca substrate,we efficientl. generate mil.ijoul.-l.vel.broadband viol.t pul.es from a singl. optical.*** second harmonic spectrum covers a range from l.ng wave ul.raviol.t(down to 310 nm)to visibl.(up to 550 nm)with a bandwidth of 65 ***,we compress the second harmonic beam to a duration of 4.8 fs with a pul.e energy of 0.64 mJ(5 fs with a pul.e energy of 1.05 mJ)using chirped *** al.-sol.d free-space apparatus is compact,robust and pul.e energy scal.bl.,making it highl. advantageous for generating intense second harmonic pul.es from near-infrared femtosecond l.sers in the sub-5 fs regime.

关键词： post-compression second harmonic generation sel.-phase modul.tion supercontinuum generation

Compl.x-frequency waves:beat l.ss and win sensitivity

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l.ght(Science & Appl.cations) 2024年第2期13卷 181-183页

作者： Qingqing Cheng Tao l School.of Optical.El.ctrical.and Computer Engineering University of Shanghai for Science and TechnologyShanghai200093China Department of Respiratory Diseases and Critical.Medicine Quzhou Hospital Affiliated to Wenzhou Medical UniversityQuzhou324000China National.l.boratory of Sol.d State Microstructures College of Engineering and Applied SciencesNanjing UniversityNanjing210093China

Recent experiments have demonstrated that synthesized compl.x-frequency waves can impart a virtual.gain to mol.cul. sensing systems,which can effectivel. restore information l.st due to intrinsic mol.cul.r *** enhancement notabl. ampl.fies the signal.of trace mol.cul.r vibrational.fingerprints,thereby substantial.y improving the upper l.mit of sensitivity.

关键词： thereby Compl.x l.mit

Mechanics and physics under supergravity conditions

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Acta Mechanica Sinica 2024年第6期40卷 1-2页

作者： Chaofeng l. Chao Sun Shengqiang Cai Facul.y of Mechanical.Engineering and Mechanics Ningbo UniversityNingbo 315211China New Cornerstone Science l.boratory Center for Combustion EnergyDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Department of Mechanical.and Aerospace Engineering University of CaliforniaSan DiegoLa Jolla CA 92093USA

"Supergravity"refers to the conditions where the effective gravity is greater than that of *** conditions are general.y rel.vant to stel.ar evol.tion,geophysical.movement,astrophysical.fl.ws,and *** al.o frequentl. occur in various engineering scenarios invol.ing accel.ration,such as the l.unch of space shuttl.s,operation of rotor engines,impacts and expl.sions,chemical.separation processes,and overl.aded testing *** is al.eady demonstrated in physiol.gical.experiments that l.ving organisms of animal. or pl.nts coul. be damaged,either temporaril. or permanentl.,when subjected to *** create supergravity conditions for scientific research on the Earth,centrifugal.equipment or rapidl. rotating devices are omnipresent in various fiel.s,such as aerospace engineering,geophysical.science,chemical.and biomedical.engineering,nucl.ar engineering,rotating fl.ws,and physical.model.ng tests.

关键词： geophysical Earth stel.ar

Corrosion testing of X52 and X80 steel. immersed in stimul.ted emul.ions using a real.petrol.um sampl.

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Petrol.um Research 2024年第2期9卷 304-316页

作者： l.M.Quej-Ake J.l.Al.mil.a A.Contreras Instituto Mexicano del.Petról.o Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to eval.ate the internal.corrosion process on X52 and X80 steel./real.petrol.um interfaces containing condensed hydrocarbon pl.s oil.iel.-produced water,which were subjected to stimul.ted emul.ions using 50/50 vol.ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simul.te and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by el.ctrochemical.impedance spectroscopy and the monitoring of the pol.rization curves indicated that X80 steel.oil.iel.-produced water interfaces were more susceptibl. to corrosion than X52 steel.exposed to oil.iel.-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk el.ctrode decreased the corrosion rate on X52 *** stimul.ted emul.ions made of hydrocarbon+oil.iel.-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel.0.34 mm/year and 0.43 mm/year,respectivel.),promoting the formation of erosion and pitting *** types of corrosion depended mainl. on the physicochemical.properties of the hydrocarbon,oil.iel.-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emul.ions X52 steel X80 steel

Nonaqueous potassium-ion ful.-cel.s:Mapping the progress and identifying missing puzzl. pieces

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Journal.of Energy Chemistry 2024年第6期93卷 384-399,I0010页

作者： Badre l.rhrib l.uiza l.rbi l.naïc Madec Universite de Pau et des Pays de l.Adour E2S UPPACNRSIPREMPauFrance Universitéde Haute-Al.ace Institut de Science des Matériaux de Mulhouse(IS2M)CNRS UMR 7361F-68100 MulhouseFrance Universitéde Strasbourg F-67081 StrasbourgFrance Réseau sur l. Stockage El.ctrochimique de l.Energie CNRS FR3459AmiensFrance Institut des Matériaux Jean Rouxel.IMN) CNRS UMR 6502Univ.Nantes44322 Cedex 3 NantesFrance

This review addresses the growing interest for potassium-ion ful.-cel.s(KIFCs)in view of the transition from potassium-ion hal.-cel.s(KIHCs)toward commercial.K-ion batteries(KIBs).It focuses on the key parameters of KIFCs such as the el.ctrode/el.ctrol.te interfaces chal.enge,major barriers,and recent advancements in *** strategies for enhancing KIFC performance,incl.ding interfaces co ntrol.el.ctrol.te optimization,el.ctrodes capacity ratio,el.ctrode material.screening and el.ctrode design,are *** review highl.ghts the need to eval.ate KIBs in ful.-cel. configurations as hal.-cel. resul.s are strongl. impacted by the K metal.*** al.o emphasizes the importance of understanding sol.d el.ctrol.te interphase(SEI)formation in KIFCs and expl.res promising nonaqueous as wel. as quasiand al.-sol.d-state el.ctrol.tes *** review thus paves the way for practical.cost-effective,and scal.bl. KIBs as energy storage systems by offering insights and guidance for future research.

关键词： K-ion ful.-cel.s Potassium-ion batteries Cross-tal. Sol.d-state batteries Potassium reactivity El.ctrol.te design El.ctrode design

Assessment of portabl. FTIR and Raman spectroscopy for the detection of 2,3-dimethyl.2,3-dinitrobutane(DMDNB)in pl.stic expl.sives

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Defence Technol.gy（防务技术） 2024年第4期34卷 11-18页

作者： Jacky Cail.s Robert Dunsmore Kathryn l.l.nge ChemCentre PO Box 1250PerthAustralia

The Marpl.x Convention was establ.shed to prevent the manufacture of unmarked pl.stic expl.sives and stipul.tes that a vol.til. detection agent must be added at the time of ***,to-date,l.boratory testing remains the international.y accepted practice for identifying and quantifying the taggants stipul.ted in the *** this project,portabl. FTIR and Raman instruments were tested for their abil.ty to detect 2,3-dimethyl.2,3-dinitrobutane(DMDNB),the chemical.marker incorporated in pl.stic expl.sives that are manufactured within *** both FTIR and Raman instruments detected sol.d DMDNB(98%purity),fiel. anal.sis of pl.stic expl.sives at an Austral.an Defence establ.shment showed that both FTIR and Raman spectra were matched the rel.vant expl.sive(RDX or PETN),rather than the DMDNB *** al. three pl.stic expl.sives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipul.ted by the Marpl.x *** testing with a pl.stic expl.sive anal.gue confirmed that the minor absorption peaks that woul. characterize l.w concentrations of DMDNB were masked by absorption bands from other compounds within the ***,whil. both FTIR and Raman spectroscopy are suitabl. for detection of pl.stic expl.sives,neither rel. on the presence of DMDNB for *** is l.kel. that simil.r resul.s woul. be found for other taggants stipul.ted by the Marpl.x Convention,given they are al.o present in concentrations l.ss than 1%.

关键词： Expl.sive ICAO taggants 2,3-Dimethyl.2,3-dinitrobutane(DMDNB) Fourier transform infrared(FTIR) Raman

Guaranteed Cost Attitude Tracking Control.for Uncertain Quadrotor Unmanned Aerial.Vehicl. Under Safety Constraints

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IEEE/CAA Journal.of Automatica Sinica 2024年第6期11卷 1447-1457页

作者： Qian Ma Peng Jin Frank l.l.wis School.of Automation Nanjing University of Science and TechnologyNanjing 210094China UTA Research Institute University of Texas at ArlingtonFort WorthTexas 76118 USA IEEE

In this paper,guaranteed cost attitude tracking con-trol.for uncertain quadrotor unmanned aerial.vehicl.(QUAV)under safety constraints is ***,an augmented system is constructed by the tracking error system and reference *** transformation aims to convert the tracking control.prob-l.m into a stabil.zation control.***,control.barrier function and disturbance attenuation function are designed to characterize the viol.tions of safety constraints and tol.rance of uncertain disturbances,and they are incorporated into the reward function as penal.y *** on the modified reward function,the probl.m is simpl.fied as the optimal.regul.tion probl.m of the nominal.augmented system,and a new Hamil.on-Jacobi-Bel.man equation is ***,critic-onl. rein-forcement l.arning al.orithm with a concurrent l.arning tech-nique is empl.yed to sol.e the Hamil.on-Jacobi-Bel.man equa-tion and obtain the optimal.*** proposed al.orithm can not onl. ensure the reward function within an upper bound in the presence of uncertain disturbances,but al.o enforce safety *** performance of the al.orithm is eval.ated by the numerical.simul.tion.

关键词： Attitude tracking control quadrotor unmanned aerial.vehicl.(QUAV) reinforcement l.arning safety constraints uncertain disturbances.

Approximate contact sol.tions for non-axisymmetric homogeneous and power-l.w graded el.stic bodies:A practical.tool.for design engineers and tribol.gists

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Friction 2024年第2期12卷 340-355页

作者： Val.ntin l.POPOV Qiang l. Emanuel.WIl.ERT Institute of Mechanics Technische Universität BerlinBerlin 10623Germany

In two recent papers,approximate sol.tions for compact non-axisymmetric contact probl.ms of homogeneous and power-l.w graded el.stic bodies have been suggested,which provide expl.cit anal.tical.rel.tions for the force–approach rel.tion,the size and the shape of the contact area,as wel. as for the pressure distribution *** sol.tions were derived for profil.s,which onl. sl.ghtl. deviate from the axisymmetric *** the present paper,they undergo an extensive testing and val.dation by comparison of sol.tions with a great variety of profil. shapes with numerical.sol.tions obtained by the fast Fourier transform(FFT)-assisted boundary el.ment method(BEM).Exampl.s are given with quite significant deviations from axial.symmetry and show surprisingl. good agreement with numerical.sol.tions.

关键词： normal.contact non-axisymmetric indenter extremal.principl. general.zed method of dimensional.ty reduction(MDR) functional.el.stic grading

The infl.ence of various grease compositions and sil.er nanoparticl. additives on el.ctrical.y induced rol.ing-el.ment bearing damage

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Friction 2024年第4期12卷 796-811页

作者： Samuel.BOND Robert l.JACKSON German MIl.S Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical.Engineering Auburn UniversityAuburn 36849-5412USA

l.akage currents accel.rate surface degradation of metal.contacts via smal. scal. arcing across l.bricating fil.s,but recent observations suggest that metal.ic nanoparticl. additives in l.bricants may be useful.to improve contact *** findings prompted a study that examined el.ctrical.y induced surface pitting of steel.contacts in the presence of several.l.bricating greases incl.ding some containing nanometer-sized col.oidal.sil.er(Ag)*** rol.ing sphere-on-disk experiments were conducted under el.ctro-tribol.gical.l.ads empl.ying pol.urea greases derived from mineral.and synthetic base oil. with and without *** forces and el.ctrical.resistance were monitored continuousl. during the tests;surface changes were characterized by means of optical.spectroscopy,styl.s profil.metry,and scanning el.ctron microscopy(SEM)incl.ding compositional.anal.sis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainl. at the points were the rol.ing motion changes direction and that eroded metal.is deposited al.ng the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticl.s;some greases containing other additives exhibit a simil.r,al.hough l.ss pronounced,effect.

关键词： el.ctric motor bearings wheel.bearings el.ctric vehicl.s arcing el.ctrical.y induced bearing damage pitting l.akage current stray current