- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- High resolution
- Organic light-emitting diodes
- Solution process
- Electrohydrodynamic printing
- Optoelectronic Information Materials and Devices
- South China University of Technology
-
Fabrication and photocatalytic performance evaluation of hydrodynamic erosion–resistant nano-TiO2–silicone resin composite films
摘要： Herein, we present the preparation of nano-TiO2–silicone resin composite films by double liquid phase spray deposition. The films exhibit better adhesion stability and photocatalytic activity under a hydrodynamic erosion condition than conventional nano-TiO2 composite films. The TiO2 layer morphology and effective TiO2 coverage ratio (CR) were affected by the initial curing time (ICT) of the silicone resin, e.g., the increase in an ICT from 10 to 40 min resulted in a CR change from 79.1 to 98.7%. The surface morphology evolution of composite films was studied under a hydrodynamic erosion period of 4 weeks. Obtained results allowed the 4-week evolution to be divided into four stages (pitting, crack pregnant, banded stripping, and surface stripping periods), additionally revealed that the CR of all samples was remained above 65%. The photocatalytic activity of composite films before and after 4-week hydrodynamic erosion was evaluated by rhodamine B degradation experiments. The 4-week erosion only led to the decrease of the photodegradation efficiencies by less than 40% in all cases. Thus, the fabricated TiO2–silicone composite films demonstrated excellent durability and photocatalytic activity under the conditions of long-term hydrodynamic erosion, allowing one to conclude that this work paves the way to the fabrication of next-generation photocatalytic materials for industrial applications.
关键词： Photocatalysis,Film formation mechanism,Silicone resin,Photodegradation,Hydrodynamic erosion resistance,Nano-TiO2
更新于2025-09-23 15:23:52
-
Detection and visualization of water surface three-wave resonance via a synthetic Schlieren method
摘要： Three-wave resonance is one of the most fundamental energy-transfer mechanisms that can occur among weakly nonlinear surface waves. Here we show experimentally that if two source waves are propagating at an angle to each other, the conditions for three-wave resonances are satisfied and a third resultant wave is produced. We present 3D visualization of surface waves using the Free-Surface Synthetic Schlieren (FS-SS) method, which removes the need for the addition of a light-diffusing agent, thereby retaining the surface tension and viscous properties of water. For three triad frequencies, we compute the average temporal power spectral density (PSD) of the wave heights. The direction of wave propagation is visualized by integrating the temporal PSD and by obtaining the average spatial PSD for each triad. Our results are in good agreement with the theory.
关键词： Hydrodynamic waves,Signal Processing,Flow visualization and imaging
更新于2025-09-23 15:23:52
-
Generalized local analogue model for nonlocal plasmonic nanostructures based on multiple-fluid hydrodynamic framework
摘要： The control and manipulation of light waves is a long-standing ambition with profound implications for the development of science and technology. Recent advances in nanofabrication allow for a rapid progress in engineering plasmonic nano-devices which collect and concentrate light or electromagnetic waves into a subwavelength region, enabling various applications in nanophotonics, such as bio-sensor with enhanced sensitivity, plasmonic laser, plasmonic colors and quantum plasmonics, to name a few. Spatial dispersion plays a critical role in nanophotonics when small plasmonic structures with feature sizes of few nanometers are handled. Such nonlocality is typically considered in a hydrodynamic framework and generally requires solving coupled partial differential equations, and therefore is involved. We develop a generalized local analogue model to reflect the nonlocal effects of plasmonic structures and avoid the complicated analysis within the multiple-fluid hydrodynamic framework, where more than one kind of charge carriers is considered. We show that spatial nonlocality can be represented by simply replacing the nonlocal surface region with an in-situ artificial local dispersive film. With such an elegant and simple-to-use alternative, the conventional analysis and simulations in the local regime acquire nonlocal capability, sufficient for a quantitative description of various plasmonic structures in nanoscale, rendering a much simpler process and great practical advantages in the numerical treatment.
关键词： multiple fluid,in-situ local model,nonlocal response,hydrodynamic Drude model
更新于2025-09-23 15:21:01
-
Demonstration of Scale-Invariant Rayleigh-Taylor Instability Growth in Laser-Driven Cylindrical Implosion Experiments
摘要： Rayleigh-Taylor instability growth is shown to be hydrodynamically scale invariant in convergent cylindrical implosions for targets that varied in radial dimension and implosion timescale by a factor of 3. The targets were driven directly by laser irradiation providing a short impulse, and instability growth at an embedded aluminum interface occurs as it converges radially inward by a factor of 2.25 and decelerates on a central foam core. Late-time growth factors of 14 are observed for a single-mode m ? 20 azimuthal perturbation at both scales, despite the differences in laser drive conditions between the experimental facilities, consistent with predictions from radiation-hydrodynamics simulations. This platform enables detailed investigations into the limits of hydrodynamic scaling in high-energy-density systems.
关键词： high-energy-density physics,hydrodynamic scaling,laser-driven implosions,Rayleigh-Taylor instability
更新于2025-09-23 15:21:01
-
Influence of the Nonlocal Effect on the Optical Properties of Nonspherical Plasmonic Semiconductor Nanoparticles
摘要： Noble metals are commonly used as plasmon materials because of their high density of free electrons, but semiconductor materials are also becoming of interesting in this field because its electron density can be varied by doping. Metal nitrides can be an alternative to noble metals because of their low absorption loss and high electron density. Among others, TiN and ZrN seem to be most suitable as alternative plasmonic materials because their optical properties are dominated by conduction electrons near the plasmon frequency. There is the flame spray pyrolysis process, which is currently developed to produce such kind of nanoparticles. In this paper, based on an extension of the discrete sources method, the effect of the hydrodynamic Drude model of the quantum nonlocal effect on the optical characteristics of semiconductor nanoparticles is analyzed. The influence of accounting for the nonlocal effect (NLE) on the optical properties under spherical particles deformation has been investigated. It has been shown that accounting for the NLE leads to a plasmon resonance blue shift and a damping similar to noble metals. It was found that smaller particles demonstrate larger NLE influence than larger ones. Besides, the influence of polarization on the local and nonlocal responses of 3D nonspherical semiconductor particles has been investigated as well. Using simulation accounting for the nonlocal effect, it is shown that the extinction of a nonspherical ZrN particles exceeds that of a gold particle.
关键词： discrete sources method,nonlocal effect,hydrodynamic Drude model,nonspherical semiconductor nanoparticle,plasmonics,Light scattering
更新于2025-09-23 15:21:01
-
Surface functionalization by nanosecond-laser texturing for controlling hydrodynamic cavitation dynamics
摘要： The interaction between liquid flow and solid boundary can result in cavitation formation when the local pressure drops below vaporization threshold. The cavitation dynamics does not depend only on basic geometry, but also on surface roughness, chemistry and wettability. From application point of view, controlling cavitation in fluid flows by surface functionalization is of great importance to avoid the unwanted effects of hydrodynamic cavitation (erosion, noise and vibrations). However, it could be also used for intensification of various physical and chemical processes. In this work, the surfaces of 10-mm stainless steel cylinders are laser textured in order to demonstrate how hydrodynamic cavitation behavior can be controlled by surface modification. The surface properties are modified by using a nanosecond (10–28 ns) fiber laser (wavelength of 1060 nm). In such a way, surfaces with different topographies and wettability were produced and tested in a cavitation tunnel at different cavitation numbers (1.0–2.6). Cavitation characteristics behind functionalized cylindrical surfaces were monitored simultaneously by high-speed visualization (20,000 fps) and high frequency pressure transducers. The results clearly show that cavitation characteristics differ significantly between different micro-structured surfaces. On some surfaces incipient cavitation is delayed and cavitation extent decreased in comparison with the reference – a highly polished cylinder. It is also shown that the increased surface wettability (i.e., hydrophilicity) delays the incipient cavitation.
关键词： Surface engineering,Laser texturing,Hydrodynamic cavitation,Fluid dynamics,Hydrophobic/hydrophilic surface
更新于2025-09-23 15:19:57
-
Monitoring strong coupling in nonlocal plasmonics with electron spectroscopies
摘要： Plasmon-exciton polaritons provide exciting possibilities to control light-matter interactions at the nanoscale by enabling closer investigation of quantum optical effects and facilitating novel technologies based, for instance, on Bose-Einstein condensation and polaritonic lasing. Nevertheless, observing and visualizing polaritons is challenging, and traditional optical microscopy techniques often lead to ambiguities regarding the emergence and strength of the plasmon-exciton coupling. Electron microscopy offers a more robust means to study and verify the nature of plexcitons, but it is still hindered by instrument limitations and resolution. A simple theoretical description of electron beam-excited plexcitons is therefore vital to complement ongoing experimental efforts. Here we apply analytic solutions for the electron-loss and photon-emission probabilities to evaluate plasmon-exciton coupling studied either with the recently adopted technique of electron energy-loss spectroscopy, or with the so-far unexplored in this context cathodoluminescence spectroscopy. Foreseeing the necessity to account for quantum corrections in the plasmonic response, we extend these solutions within the framework of general nonlocal hydrodynamic descriptions. As a specific example, we study core-shell spherical plasmon-molecule hybrids, going beyond the standard local-response approximation through the hydrodynamic Drude model for screening and the generalized nonlocal optical response theory for nonlocal damping. We show that electron microscopies are extremely powerful in describing the interaction of emitters with the otherwise weakly excited by optical means higher-order plasmonic multipoles, a response that survives when quantum-informed models are considered. Our work provides, therefore, both a robust theoretical background and supporting argumentation to the open quest for improving and further utilizing electron microscopies in strong-coupling nanophotonics.
关键词： electron energy-loss spectroscopy,nonlocal hydrodynamic descriptions,cathodoluminescence spectroscopy,quantum plasmonics,Plasmon-exciton polaritons
更新于2025-09-23 15:19:57
-
Modeling radiative-shocks created by lasera??cluster interactions
摘要： Radiative-shocks induced by laser–cluster interactions are modeled using radiation-hydrodynamic simulations. A good agreement—in both shock velocity and density pro?les—is obtained between experiment and simulations, indicating that non-local thermodynamic equilibrium (NLTE) radiative effects are important in the experimental regime examined, particularly at early times ((cid:2)30 ns) due to the elevated temperatures ((cid:3)35 eV). The enhanced NLTE radiative emission causes the shock to be reduced in amplitude, increased in width, and reduced in propagation velocity, while the amplitude of the radiative precursor is increased. As the density and temperature conditions are relatively modest, this potentially has important implications for the scalings that are used in laboratory–astrophysics to transform between laboratory and astrophysical scales, which do not hold for non-LTE systems.
关键词： non-local thermodynamic equilibrium,laboratory–astrophysics,radiation-hydrodynamic simulations,radiative-shocks,laser–cluster interactions
更新于2025-09-23 15:19:57
-
Evaluation of the hydraulic and hydrodynamic parameters influencing photo-catalytic degradation of bio-persistent pollutants in a pilot plant
摘要： A kinetic study on the photo-catalytic degradation of bio-persistent micro-pollutants, as methyl red and methylene blue dyes, was carried out on an innovative unit by changing the hydraulic and hydrodynamic parameters of the system. The catalyst (TiO2, anatase) was embedded into a cement matrix and deposited at the bottom of a channel to activate the UVB photo-degradation reactions. The influence of the catalyst dosage, substrate concentration c0, and pH was evaluated on the degradation rates. The optimum catalytic dose was obtained at 0.79 g/cm3 while the best results were observed at 0.7 mg/L influent dye concentration. The pH of the solution influenced the sorption phenomena because the charge of the substrates functional groups as well as the charge of the catalyst surface were affected by this parameter. Different unit geometries, hydraulic loads (hw) and gradients (i) affected speed and flow-rate (Q) of the liquid phase and, as a consequence, the irradiated retention times (Irt) of the substrates to the UV/TiO2 system. Kinetics resulted faster at increasing flow-rates of the liquid flowing through the channel, constant the hydraulic load, whereas the increase in the hydraulic load did not improve the performances. Finally, degradation rates slightly decreased after the increase in the hydraulic gradient of the channel.
关键词： Organic micro-pollutant removal,Hydraulic and hydrodynamic parameters,Kinetic study,Photo-catalysis,Textile wastewater,Pilot plant
更新于2025-09-19 17:15:36
-
Carbon dots: synthesis, formation mechanism, fluorescence origin and sensing applications
摘要： This paper presents a thermal elasto-hydrodynamic lubrication (EHL) model for analyzing crowned roller lubrication performances under the influence of frictional heating. In this thermal EHL model, the Reynolds equation is solved to obtain the film thickness and pressure results while the energy equation and temperature integration equation are evaluated for the temperature rise in the lubricant and at the surfaces. The Discrete convolution fast Fourier transform (DC-FFT) method is utilized to calculate the influence coefficients for both the elastic deformation and the temperature integration equations. The influences of slide-to-roll ratio (SRR), load, crowning radius, and roller length on the roller lubrication and temperature rise are investigated. The results indicate that the thermal effect becomes significant for the cases with high slide-to-roll ratios or heavy loads. The proposed thermal EHL model is used to study the thermal-tribology behavior of an apex seal-housing interface in a rotary engine, and to assist the design of the apex seal crown geometry. A simplified crown design equation is obtained from the analysis results, validated through comparison with the optimal results calculated using the current crowned-roller TEHL model.
关键词： Roller contact,thermal elasto-hydrodynamic lubrication (TEHL),crowned surface
更新于2025-09-19 17:15:36