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oe1(光电查) - 科学论文

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?? 中文(中国)
  • Editorial: Special Issue a??Laser-Induced Periodic Surface Nano- and Microstructures for Tribological Applicationsa??

    摘要: Laser material processing is an innovative technology that generates surface functionalities on the basis of optical, mechanical, or chemical properties. In the form of laser surface texturing (LST), it has attracted a remarkable amount of research to tailor surface properties towards various tribological applications. Of this single-step, laser-based technology, the main advantages are the contactless machining, featuring a high flexibility, efficiency, and speed, along with the excellent quality of the processed products. LST can be applied precisely, localized to sub-micrometric areas, but, via laser beam scanning, it is also feasible for structuring large surface areas the size of square-meters.

    关键词: microstructure,wear,laser-induced periodic surface structures (LIPSS),lubricant,applications,friction,tribology,nanostructure

    更新于2025-09-23 15:19:57

  • Reactive Pulsed Laser Deposition of Clustered-Type MoSx (x ~ 2, 3, and 4) Films and Their Solid Lubricant Properties at Low Temperature

    摘要: We studied the tribological properties of amorphous molybdenum sulfide (MoSx) thin-film coatings during sliding friction in an oxidizing environment at a low temperature (?100 °C). To obtain films with different sulfur contents (x ~ 2, 3, and 4), we used reactive pulsed laser deposition, where laser ablation of the Mo target was performed in H2S at various pressures. The lowest coefficient of friction (0.08) was observed during tribo-testing of the MoS3 coating. This coating had good ductility and low wear; the wear of a steel counterbody was minimal. The MoS2 coating had the best wear resistance, due to the tribo-film adhering well to the coating in the wear track. Tribo-modification of the MoS2 coating, however, caused a higher coefficient of friction (0.16) and the most intensive wear of the counterbody. The MoS4 coating had inferior tribological properties. This study explored the mechanisms of possible tribo-chemical changes and structural rearrangements in MoSx coatings upon contact with a counterbody when exposed to oxygen and water. The properties of the tribo-film and the efficiency of its transfer onto the coating and/or the counterbody largely depended on local atomic packing of the nanoclusters that formed the structure of the amorphous MoSx films.

    关键词: wear,molybdenum sulfides,solid lubricants,nanoclusters,reactive pulsed laser deposition,low temperature,coefficient of friction

    更新于2025-09-23 15:19:57

  • Corrosion wear and electrochemical corrosion behaviors of laser cladded amorphous FeSiB coating in 3.5% NaCl solution

    摘要: An amorphous FeSiB composite coating was fabricated on S355 structural steel using a laser cladding. The corrosion wear and electrochemical corrosion behaviors of FeSiB coating in 3.5% NaCl solution were investigated using a wear tester and electrochemical workstation. The results show that the FeSiB coating with the hardness of 601 HV is primarily composed of amorphous and crystal phases of α–Fe(Si) and Fe2B. The average coefficients of friction (COFs) of FeSiB coating at the wear loads of 3, 5 and 7 N loads are 0.888, 0.751, and 0.564, respectively, which deceases with the increase of wear loads; and the corresponding wear rates are 7.60, 8.02 and 10.04 μm3?N–1?m–1, respectively. The corrosion potentials of FeSiB coating and substrate are –0.718 and –1.042 V, respectively, exhibiting that the corrosion potential of FeSiB coating shifts positively, its corrosion resistance was higher than that of substrate.

    关键词: electrochemical corrosion,amorphous FeSiB composite coating,coefficient of friction (COF),wear mechanism,laser cladding (LC)

    更新于2025-09-23 15:19:57

  • Anisotropic nanoscale and sub-nanoscale friction behaviors between phosphorene and silicon tip

    摘要: Understanding the frictional properties of phosphorene is essential for reliable fabrication and sustainable operation of phosphorene-based nanotechnology devices. Although recent studies have revealed that phosphorene exhibits anisotropic frictional characteristics, the detailed mechanisms are not well analyzed, and the influence of some experimental parameters (e.g., spring stiffness, tip load force, and tip size), which are very sensitive to atomic frictional forces, were not considered. This study was carried out to address the above shortcomings. The anisotropic frictional behavior of phosphorene and its detailed mechanism were analyzed using potential energy profiles. Also, the effects of spring stiffness and tip load force on the stick-slip behaviors were investigated. Furthermore, we studied the sub-nanoscale stick-slip behavior during the nanoscale slip motion. The nanoscale and sub-nanoscale stick-slip phenomena were originated from the tip’s behavior of passing over the bond between the phosphorus atoms and over the puckered honeycomb structure along the zigzag and armchair directions. We utilized a simple one-dimensional model to explain the energy profiles. The influence of tip size on the stick-slip behavior was also examined and found related to the initial nanoscale slip velocity. As the tip diameter decreased, a high-frequency sub-nanoscale stick-slip phenomenon and shorter nanoscale slip duration were identified.

    关键词: nano/sub-nanoscale friction,phosphorene,stick-slip,molecular dynamics,friction force microscope

    更新于2025-09-19 17:15:36

  • An Overview of Research into Low Internal Friction Optical Coatings by the Gravitational Wave Detection Community

    摘要: The direct detection of gravitational waves by ground-based interferometric gravitational wave detectors in recent years has opened a new window of the universe, allowing the astrophysical observations of previously unexplored phenomena, such as the collisions of black holes and neutron stars. However, small thermodynamic fluctuations of the density of the thin films that compose the mirrors used within the gravitational wave detectors, such as the LIGO and Virgo detectors, give rise to noise which limits these instruments at their most sensitive frequencies. This 'Brownian Thermal Noise' can be related to the inherent internal friction of the mirror materials through the fluctuation-dissipation theorem. Therefore, the improved sensitivity of gravitational wave detectors depends, to some extent, upon the development of optical thin films with low internal friction. The past two decades have therefore seen the growth of internal friction experiments undertaken within the gravitational wave detection community. This article attempts to summarize the results of these investigations and to highlight current research directions in order to foster a stronger dialogue with the larger internal friction and mechanical spectroscopy community.

    关键词: LIGO,Optical Films,Internal Friction

    更新于2025-09-19 17:15:36

  • Effects of LED Light Color and Intensity on Feather Pecking and Fear Responses of Layer Breeders in Natural Mating Colony Cages

    摘要: The friction properties play an important role in diamond polishing, which significantly affect the interfacial contact and material removal. In this paper, the friction force and coefficient of friction (COF) during diamond polishing process were monitored under different loads and rotating speeds. The results show that the friction force and COF both increase with the load, and decrease with the rotating speed. The bearing capacity of liquid film is enhanced at large rotating speed, which leads to the decrease of friction force. According to the binomial law of friction, the increase of actual contact area caused by high load contributes to the increase of COF. Besides, it is found that the addition of H2O2 reduces the friction coefficient through surface adsorption. In order to further reveal the mechanism of friction variation at the atomic level, the friction behavior at a local area of interface between the diamond substrate and the abrasive particle in diamond polishing process was investigated by molecular dynamics (MD) method. The simulation results indicate that the interfacial bridge bonds formed between the substrate and particle under the action of load lead to the increase of friction force.

    关键词: molecular dynamics,coefficient of friction,diamond,friction,polishing

    更新于2025-09-19 17:13:59

  • [IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - The Journey from Manipulating Single Quantum Systems to Quantum Information Processing

    摘要: The quality factor of a resonator represents the decay of vibrational energy over time, and is directly related to the frequency response and other key parameters that determine performance of inertial sensors and oscillators. Accurate prediction of the quality factor is essential for designing high-performance microelectromechanical (MEMS) devices. Several to the quality factor. Due to computational complexity, highly simplified models for the dominant dissipation mechanism, such as Zener’s model for thermoelastic dissipation (TED), are often the intuition provided by these models employed. However, is inadequate to predict the quality factor of more complex designs and can be highly misleading. In this paper, we construct complete, quantitative, and predictive models with finite-element methods for the intrinsic energy dissipation mechanisms in MEMS resonators using full anisotropic representation of crystalline silicon and the temperature dependence of all parameters. We find that TED is often a more significant source of damping than has been assumed, because of the previously neglected role of crystalline anisotropy and small geometric features, such as etch release holes—all of which can now be included in practical models. We show that these models, along with simpler scaling models for extrinsic dissipation mechanisms, explain measurements of quality factor in diverse sets of MEMS resonators with unprecedented accuracy.

    关键词: internal friction,frequency response,micromechanical resonators,microelectromechanical devices,thermal-mechanical coupling,thermoelastic dissipation,geometry,resonance,systems,Capacitive sensors,damping,energy dissipation,frequency-domain analysis

    更新于2025-09-19 17:13:59

  • On the Role of a ZDDP in the Tribological Performance of Femtosecond Laser-Induced Periodic Surface Structures on Titanium Alloy against Different Counterbody Materials

    摘要: Laser-induced periodic surface structures (LIPSS, ripples) with ~500–700 nm period were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond laser. The tribological performance of the surfaces were quali?ed in linear reciprocating sliding tribological tests against balls made of di?erent materials using di?erent oil-based lubricants. The corresponding wear tracks were characterized by optical and scanning electron microscopy and confocal pro?lometry. Extending our previous work, we studied the admixture of the additive 2-ethylhexyl-zinc-dithiophosphate to a base oil containing only anti-oxidants and temperature stabilizers. The presence of this additive along with the variation of the chemical composition of the counterbodies allows us to explore the synergy of the additive with the laser-oxidized nanostructures.

    关键词: laser-induced periodic surface structures (LIPSS),friction,lubricant additives,wear

    更新于2025-09-19 17:13:59

  • The effect of wind on the temperature distribution of photovoltaic modules

    摘要: This paper discusses the thermal aspect of two different types of PV modules. The PV modules are categorised into two major groups: Frameless and Framed modules, and designing structure. Apart from the framed structure, thermal behaviour and its implicit effect on the system is also the key factor of the analysis. Two similar classes of modules are relatively examined and thereafter, are compared with differently manufactured (structure-wise) modules. Here, the framed modules, Solarex (pc-Si) and the RWE Schott Solar (pc-Si) are optically similar; whereas the Solar watt (c-Si) and the Duna Solar (a-Si) are frameless modules. A parallel dichotomy is established on the basis of the quality of the modules being used by the energy industry and the thermal response of the modules at the given conditions. The assessment of the PV modules is based upon the angular orientation of wind, thermal diffusivity of surface, thermal conductivity, heat transfer coefficient, inertial effect of surface, drag force, skin friction, and the thermal behaviour at vicinity of PV surface. The energy equation of the thermal boundary layer over the flat plate is used for thermal profiling of the different PV surfaces. From the experimental measurement, the ambience temperature, surface temperature and wind speed have been determined. The qualitative investigation of geometrically as well as structurally different solar modules is performed with the help of ODE45 application. The flow of air is laminar for all the modules and the drag force varies from 1.45 × 10?5 N to 2.10 × 10?5 N. Friction loss due to wind flow is found to be least for the Solar watt, while the wind orientation of 10° North of East keeps the temperature deviation of the surface from its ambience low for all the modules. The effect of the thermal boundary layer is relatively significant for the Solar watt and the RWE Schott solar modules. Hydrodynamic boundary layer formation has been demarcated from thermal boundary using Blasius and Pohlhausen’s solutions for momentum and energy equations of fluid past a flat surface.

    关键词: Temperature distribution,Flow parameters,Thermal analysis,Skin friction,Windspeed,Photovoltaic modules

    更新于2025-09-19 17:13:59

  • [IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Electro-thermal Model of Approximated Organic Tissue for Investigation of Harmful Electrosurgical Impacts

    摘要: The quality factor of a resonator represents the decay of vibrational energy over time, and is directly related to the frequency response and other key parameters that determine performance of inertial sensors and oscillators. Accurate prediction of the quality factor is essential for designing high-performance microelectromechanical (MEMS) devices. Several to the quality factor. Due to computational complexity, highly simplified models for the dominant dissipation mechanism, such as Zener’s model for thermoelastic dissipation (TED), are often the intuition provided by these models employed. However, is inadequate to predict the quality factor of more complex designs and can be highly misleading. In this paper, we construct complete, quantitative, and predictive models with finite-element methods for the intrinsic energy dissipation mechanisms in MEMS resonators using full anisotropic representation of crystalline silicon and the temperature dependence of all parameters. We find that TED is often a more significant source of damping than has been assumed, because of the previously neglected role of crystalline anisotropy and small geometric features, such as etch release holes—all of which can now be included in practical models. We show that these models, along with simpler scaling models for extrinsic dissipation mechanisms, explain measurements of quality factor in diverse sets of MEMS resonators with unprecedented accuracy.

    关键词: micromechanical resonators,energy dissipation,Capacitive sensors,frequency-domain analysis,damping,frequency response,geometry,thermal-mechanical coupling,resonance,thermoelastic dissipation,internal friction,microelectromechanical devices,systems

    更新于2025-09-19 17:13:59