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Stabilization of mix.d-halide lead perovskites under light by photothermal effects

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Journal of energy Chemistry 2021年第12期30卷 8-11,I0001页

作者： Juvinch r.Vicente Martin e.Kordesch Jix.n Chen Department of Chemistry and Biochemistry Ohio UniversityAthensOH 45701United States Nanoscale and Quantum Phenomena Institute Ohio UniversityAthensOH 45701United States Department of Chemistry University of the Philippines VisayasMiagaoIloilo 5023Philippines Department of Physics and Astronomy Ohio UniversityAthensOH 45701United States

Mix.d-halide lead perovskites(MHLPs) are semiconductor materials with bandgaps that are tunable across the visible spectrum and have seen promising applications in photovoltaics and ***, their segregation into phases with enriched halide components, under resonant light illumination and/or electric field, have hindered their practical applications. Herein, we demonstrate the stabilization of the MHLP photoluminescence(PL) peak as a function of their ex.itation *** effect is associated with the phase segregation of MHLPs and their subsequent remix.ng by photothermal heating. We conclude that the balance between these opposing processes dictates the equilibrium PL peak of the MHLPs. The findings in this work could serve as a potential approach to obtain MHLP with stable emission peaks under operating conditions.

关键词： Perovskites Phase segregation Photothermal Solar cells LeDs

Nanovolcano microelectrode arrays: toward long- term on-demand registration of transmembrane action potentials by controlled electroporation

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Microsystems & Nanoengineering 2020年第1期6卷 578-589页

作者： Benoit x.e.Desbiolles etienne de Coulon Nicolas Maino Arnaud Bertsch Stephan rohr Philippe renaud Laboratory of Microsystems LMIS4 Ecole Polytechnique Federale de LausanneLausanneSwitzerland Department of Physiology Laboratory of Cellular Optics IIUniversity of BernBernSwitzerland

Volcano-shaped microelectrodes(nanovolcanoes)functionalized with nanopatterned self-assembled monolayers have recently been demonstrated to report cardiomyocyte action potentials after gaining spontaneous intracellular *** nanovolcanoes ex.ibit recording characteristics similar to those of state-of-the-art micro-nanoelectrode arrays that use electroporation as an insertion *** this study,we investigated whether the use of electroporation improves the performance of nanovolcano arrays in terms of action potential amplitudes,recording durations,and *** with neonatal rat cardiomyocyte monolayers grown on nanovolcano arrays demonstrated that electroporation pulses with characteristics derived from analytical models increased the efficiency of nanovolcano recordings,as they enabled multiple on-demand registration of intracellular action potentials with amplitudes as high as 62 mV and parallel recordings in up to~76%of the available *** performance of nanovolcanoes showed no dependence on the presence of functionalized nanopatterns,indicating that the tip geometry itself is instrumental for establishing a tight seal at the cell–electrode interface,which ultimately determines the quality of ***,the use of electroporation permitted the recording of attenuated cardiomyocyte action potentials during consecutive days at identical sites,indicating that nanovolcano recordings are nondestructive and permit long-term on-demand recordings from ex.itable cardiac *** from demonstrating that less complex.manufacturing processes can be used for nex.-generation nanovolcano arrays,the finding that the devices are suitable for performing on-demand recordings of electrical activity from multiple sites of ex.itable cardiac tissues over ex.ended periods of time opens the possibility of using the devices not only in basic research but also in the contex. of comprehensive drug testing.

关键词： arrays recording action

INFLUeNCeS OF CASTING SPeeD AND SeN DePTH ON FLUID FLOW IN THe FUNNeL TYPe MOLD OF A THIN SLAB CASTer

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Acta Metallurgica Sinica(english Letters) 2007年第1期20卷 15-26页

作者： B.W. Li x.Y. Tian e.G. Wang J.C. He Key Laboratory of National education Ministry for electromagnetic Processing of Materials Northeastern University Shenyang 110004 China

In recent years, thin slab continuous casting technology has been widely used to improve the quality of the product and to reduce the cost. One of the challenges faced by this technology is to design reasonable flow patterns, which strongly affect the surface and inner properties of the final slab in the mold. With the fix.d scales and complex.geometrical structures of nozzle and funnel type mold, a series of numerical simulations are made to analyze the flow patterns in melt steel using finite volume method based on structured body fitted coordinate grids. The CFD （computational fluid dynamics） package is validated first using one typical case described in previously published studies, and then it is developed to study the effect of operational parameters on fluid flow in thin slab caster. Two operational parameters, casting speed and SeN （submerged entry nozzle） depth, are mainly considered for numerical analysis. On the basis of present simulations, the reasonable SeN submergence depths corresponding to different casting speeds are suggested according to fluid flow characteristics like, flow jet impingement on the narrow side of the mold, flow speed of the melt steel beneath the meniscus and the recirculation region. This is the first stage of study on the numerical analysis of the whole thin slab casting process with electromagnetic brake.

关键词： continuous casting thin slab submerged entry nozzle (SeN) numerical analysis funnel type mold standard k-ε model rNG (renormalization group) k-ε model

THe LIMITATION OF MATANSITIC INVArIANT HABIT PLANe AND MArTeNSITe MOrPHOLOGY

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Acta Metallurgica Sinica(english Letters) 1996年第4期9卷 298-306页

作者： N.J. Gu, H.F. Peng, x. Y Song, F.x. Yin and e.x. Wang(Department of Material Science and engineering Hebei University of Technology, Tianjin 300132, China

The strain tensor and displacement vector associated with lattice deformation were introduced to discuss the effect of self-accommodation and plastic accommodation in martensitic transformation,and the models for {557}_f and {3,10,15}_f martensite fomation were proposed, along with the ex.erimental verification. It is considered that the invariant habit plane may result from the self-accommodation between different martensitic variants causing the internal twin structure. However, as the strength of parent phase is low enough for the plastic accommodation to occur the dislocation substructure in martensite be produced, in which case the invariant habit plane is difficult to form so the{225}_f and {557}_f habit planes are difficult to ex.lain by the phenomenological crystallographic theory. So,there are some limitations for the martensitic invariant habit *** the present work the authors also suggest that the martensite morphology depends on the competition between self-accommodation and plastic accommodation including factors not only of strength but also of structure of the parent phase However, when the density of crystal defects is high dislocations rather than twinned martensite will form in spite of the higher strength of the parent phase.

关键词： rystallography,martensitic transformation martensite morPhology

electron mass enhancement and magnetic phase separation near the Mott transition in double-layer ruthenates

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Frontiers of physics 2018年第4期13卷 159-165页

作者： Jin Peng x. M. Gu G. T. Zhou W. Wang J. Y. Liu Yu Wang Z. Q. Mao x. S. Wu Shuai Dong School of Physics Southeast University Nanjing 211189 China Collaborative Innovation Center of Advanced Microstrucutres Lab of Solid State Microstructures School of Physics Nanjing University Nanjing 210093 China Department of Physics and engineering Physics Tulane University New Orleans LA 70118 USA

We present a detailed investigation of the specific heat of Ca3（ru1-x.x.2O7 （M = Ti, Fe, Mn） single crystals. Depending on the dopant and doping level, three distinct regions are present： a quasi- two-dimensional metallic state with antiferromagnetic （AFM） order formed by ferromagnetic bilayers （AFM-b）, a Mott insulating state with G-type AFM order （G-AFM）, and a localized state with a mix.d AFM-b and G-AFM phase. Our specific heat data provide deep insights into the Mort transitions induced by Ti and Mn doping. We observed not only an anomalous large mass enhancement, but also an additional term in the specific heat, i.e., C ∝ T2, in the localized region. The C ∝ T2 term is most likely due to long-wavelength ex.itations with both FM and AFM components. A decrease in the Debye temperature is observed in the G-type AFM region, indicating lattice softening associated with the Mott transition.

关键词： specific heat ruthenates Mort insulator phase separation

Flux.measurements for a DD neutron generator using neutron activation analysis

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Nuclear Science and Techniques 2018年第4期29卷 66-71页

作者： Walid A. Metwally Samar el-Sayed Ahmad Ababneh David L. Williams Allan x. Chen Department of Nuclear engineering University of SharjahSharjah 27272 UAE Adelphi Technology 2003 E Bayshore Rd. Redwood CityCA 94063 USA

The fast and max.mum thermal neutron flux.s from the DD-109 neutron generator at the University of Sharjah were ex.erimentally measured by the activation technique using different neutron reactions. The thermal and fast neutron flux.s were found to be 2.960 × 10~6 and6.186 × 10~7 n/cm^2 s, respectively. This was done to verify the modeling results for the optimum moderator thickness needed to max.mize the thermal neutron flux. The optimum moderator thickness was found to be between 3.5 and4 cm. The present data were compared with the detailed MCNP model-based calculation performed in earlier work to simulate the generator.

关键词： Neutron activation analysis Neutron generator Neutron moderation Thermal neutron flux measurement

In-situ loading neutron-diffraction studies of a cobalt-based superalloy

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中国有色金属学会会刊：英文版 2006年第A02期16卷 144-148页

作者： M. L. BeNSON P. K LIAW H. CHOO T. A. SALeH D. W. BrOWN M. r. DAYMOND x. L. WANG A. D. STOICA e. C. OLIVer D. L. KLArSTrOM Department of Materials Science and engineering University of Tennessee Knoxville TN 37996 USA Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA Los Alamos Neutron Science Center Los Alamos National Laboratory Los Alamos NM 87545 USA Department of Mechanical and Materials engineering Queen＇s University Kingston ON K7L3N6 Canada Spallation Neutron Source Oak Ridge National Laboratory Oak Ridge TN 37831 USA ISIS Pulsed Neutron and Muon Source Rutherford-Appleton Laboratory Chilton Didcot OX 11 0QX UK Haynes International Inc Kokomo IN 46904 USA

ULTIMeT (r) alloy is a cobalt-based superalloy that undergoes a deformation-induced phase transformation from a face-centered-cubic (fcc) phase to a hex.gonal-close-packed (hcp) phase. The transformation was studied during monotonic loading, stress-controlled high-cycle fatigue (HCF) and strain-controlled low-cycle fatigue (LCF). The HCF was performed at a max.mum stress of sigma(max. =840 MPa and a minimum stress of sigma(min) =84 MPa, while the tensile ex.eriment was terminated after reaching sigma(max. =890 MPa. The LCF was performed at. a max.mum strain of sigma(max. =1.25% and a minimum strain Of sigma(min) =-1.25%. The monotonic-loading ex.eriment results reveal that the hcp phase forms after reaching the yield stress. During HCF, the hex.gonal phase forms immediately upon the first fatigue cycle, with no further change in structure upon subsequent deformation. In contrast to HCF, the hcp phase forms gradually during LCF. In fact, fatigue cycle 12 is reached before the hcp phase is resolved by neutron diffraction. Diffraction patterns from subsequent fatigue cycles reveal that the hcp phase continues to accumulate as LCF progresses. These observations can be related to the input of mechanical energy during different loading modes.

关键词：钴基高温合金现场加载中子衍射 fcc hcp 相变

Monolayer MoS_(2)synaptic devices synergistically modulated by Na^(+)ions and sulfur vacancies for neuromorphic computing and pain perception stimulation

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Journal of Materials Science & Technology 2023年第32期163卷 121-131页

作者： Y.B.Liu D.Cai T.C.Zhao M.Shen x.Zhou Z.H.Zhang x.W.Meng D.e.Gu State Key Laboratory of electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China College of Chemistry and Materials Science Sichuan Normal UniversityChengdu 610066China Laboratory of Controllable Preparation and Application of Nanomaterials Chinese Academy of SciencesBeijing 100190China

Ion based synaptic devices(ISDs)are one of the ex.ellent candidates for neuromorphic ***,most of ISDs utilized additional ion sources to supply ions for adjusting the conductance of the device channel,which might hinder the large-scale integration for fabricating hierarchical artificial neural *** a high-performance monolayer MoS_(2) ISD is demonstrated using Na^(+)ions doped in MoS_(2) lattice as ion *** from the Na^(+)ions and S vacancy defects in the MoS_(2) lattice,the device not only ex.ibits various synaptic plasticity(long-and short-term plasticity)and typical biological features(pain-perceptual nociceptors and associative learning),but also has a low synaptic event response voltage(100 mV)and a low energy consumption(0.92 pJ)for a synaptic event.A dissociation-adsorptionmigration-binding model is proposed to elaborate the resistance switching mechanism,which is corroborated by density functional theory calculations and *** addition,an artificial neural network(ANN)based on MoS_(2) ISDs is simulated for the recognition of the MNIST handwritten *** deviation of the recognition accuracy is less than 8%compared to the ideal floating-point numeric *** results provide a new strategy for fabricating high-performance ISDs for neuromorphic computing.

关键词： 2D materials Monolayer Molybdenum disulfide Synapses Neuromorphic computing

Finger pad friction and tactile perception of laser treated,stamped and cold rolled micro-structured stainless steel sheet surfaces

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Friction 2017年第2期5卷 207-218页

作者： S.ZHANG x.ZeNG D.T.A MATTHeWS A.IGArTUA e.rODrIGUeZ-VIDAL J.CONTrerAS FOrTeS e.VAN Der HeIDe State Key Laboratory of Tribology Tsinghua University Beijing 100084 ChinaLaboratory for Surface Technology and Tribology Faculty of Engineering Technology University of Twente Drienerlolaan 5 Enschede 7522 NB the Netherlands Shanghai Advanced research Institute Chinese Academy of Sciences China Laboratory for Surface Technology and Tribology Faculty of Engineering Technology University of Twente Drienerlolaan 5 Enschede 7522 NB the NetherlandsTata Steel Research & Development PO Box 10000 IJmuiden 1970CA the Netherlands IK4-Tekniker C/Ignacio Goenaga 5 Eibar 20600 Spain Acerinox.europa SAU Los Barrios Spain Laboratory for Surface Technology and Tribology Faculty of Engineering Technology University of Twente Drienerlolaan 5 Enschede 7522 NB the NetherlandsTU Delft Faculty of Civil Engineering and Geosciences Stevinweg 1 Delft 2628 CN the Netherlands

Tactile perception is a complex.system,which depends on frictional interactions between skin and *** contact mechanics of tactile friction is governed by many factors such as the state and properties of skin and *** order to discover the connection between perception and tactile friction on tex.ured stainless steel sheets,both perception ex.eriments (subjective) and tactile friction measurements (objective) were performed in this *** perception ex.eriments were carried out by using a panel test method to identify the perceived roughness,perceived stickiness and comfort level from the *** the friction ex.eriments,tactile friction was measured by a multi-ax.s force/torque transducer in *** perceived stickiness was illustrated as an effective subjective stimulus,which has a negative correlation to the comfort *** significant evidence was revealed to the connection between the perceived roughness and comfort perception,and this relationship may be influenced by the participants' individual ex.erience,gender and moisture level of ***,the kinetic tactile friction was concluded as an objective stimulus to the comfort perception with a negative correlation.

关键词： tactile friction perception pleasant touch biotribology