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oe1(光电查) - 科学论文

25 条数据
?? 中文(中国)
  • Fabrication of Large Area Sub-200 nm Conducting Electrode Arrays by Self-Confinement of Spincoated Metal Nanoparticle Inks

    摘要: Here, the fabrication of sub-200 nm metal wires from commercial silver inks with 50 nm particle size, 100 times narrower than with typical low-resolution ink-jet and screen printing in flexible electronics, is demonstrated. Using a combination of spincoating on prepatterned polymer substrates and flash lamp annealing, nanoparticles merge to wires featuring good electrical conductivity. With this method less than 150 nm thin wires can be generated from 2 μm wide or smaller V-grooves due to adapted dilution of particle content, self-confinement in V-grooves, shrinkage of line width during solvent evaporation, and sintering. After nanoimprinting, grooves made from PMMA are smoothened out by thermal reflow without affecting the wires. The resistivity of 300 μm long, 400 nm wires is similar to more conventional ink-jet printed wires with 10–50 μm widths.

    关键词: self-confinement,V-groove,flash lamp annealing,nanoimprint lithography,silver nanoparticles

    更新于2025-09-23 15:23:52

  • Fabrication of Nano-Structured V-Shaped Grooves on B-Si Wafer for On-Board Spaceborne Blackbody System

    摘要: Nano-structured V-shaped grooves on the black-silicon (B-Si) was fabricated to improve the optical emissivity for on-board spaceborne blackbody system. The deep reactive ion etching (DRIE) process was used to fabricate the V-shaped grooves on the B-Si wafer according to the etching conditions. The scanning electron microscopy (SEM) and infrared (IR) spectroscopy were used to evaluate the morphology, aspect ratio, and reflectance of the fabricated B-Si specimen. The surface of the B-Si was successfully structured with the nano-scale V-shaped grooves of which the height and diameter were approximately 670 nm and 200 nm, respectively. The reflectance of the B-Si was close to zero in a wavelength less than 1 μm. As a result, the fabricated B-Si with the nano-structured V-shaped grooves was suitable to the blackbody target for on-board spaceborne blackbody system.

    关键词: On-Board Calibration,V-Shaped Groove,DRIE Process,Blackbody,Black Silicon

    更新于2025-09-23 15:22:29

  • Label-free in situ Monitoring of DNA Hybridization Chain Reaction using Sequence-selective Minor-groove Binding Fluorophores

    摘要: A novel label-free in situ monitoring system for hybridization chain reaction (HCR) using DNA minor-groove binding fluorophores, Hoechst 33258 (Hoe) or quinone cyanine-dithiazole (QCy-DT), has been developed. Two unmodified hairpin oligodeoxyribonucleotides having incomplete double-stranded AATT sequences enabled target-dependent formation of probe binding sites, i.e., AATT double-strand, in HCR product, and fluorescence enhancement of minor-groove binding fluorophores in situ. Using this system, target DNA can be detected by the fluorescence enhancement of Hoe and QCy-DT in a real-time in situ manner. Further development of a label-free, isothermal detection system might provide a cost-effective and user-friendly method for nucleic acid detection.

    关键词: Label-free,Hybridization chain reaction,Minor-groove binding fluorophore,Fluorescence,In situ detection

    更新于2025-09-23 15:22:29

  • Investigation and Prediction on Regulation of Hydrophobicity of Polymethyl Methacrylate (PMMA) Surface by Femtosecond Laser Irradiation

    摘要: This study presents the contact angle prediction model of a trapezoidal groove structure based on the laser irradiation on polymethyl methacrylate (PMMA). The trapezoidal groove structure was designed and proposed according to the characteristics of a femtosecond laser. First, the complete wetting model and incomplete wetting model which were compatible with the characteristics of the laser mechanism were constructed based on the Gibbs free energy and the structural parameters of the trapezoidal groove structure. Then, based on the contact angle prediction models constructed, the samples were divided into two groups according to the designed structural parameters, and the experimental investigations were carried out. The result demonstrated that the incomplete wetting prediction model was more in line with the actual situation. The convex width and the top edge length of spacing of the trapezoidal groove structure both affected the contact angle prediction results. From both the experimental contact angles and the contact angles predicted by the incomplete wetting model, it could be known that the contact angle reached 138.09° when the ratio of the convex width to the top edge length of spacing was 0.25, indicating that the smaller the ratio of the convex width to the top edge length of spacing, the better the hydrophobicity of PMMA.

    关键词: femtosecond laser,trapezoidal groove structure,polymethyl methacrylate,hydrophobicity

    更新于2025-09-23 15:21:01

  • Correlation between laser energetic parameters and magnetic properties of GO laminations under surface treatments with long, short or ultra-short pulsed lasers

    摘要: Electromagnetic components mostly incorporate soft magnetic materials used as flux multipliers. Hence, any reduction in iron loss of the magnetic core yields in saving energy. Among the techniques, the local laser treatment is a non-contact method applied for 180° domain refinement (Patri et al. [1]). The present study reassessed the impact of laser treatment on the magnetic properties of grain oriented silicon steels. Various laser pulse widths are used: an ultra-short pulse laser mainly adapted to the ablation process and a long and short pulse durations used for both irradiation and scribing processes [2]. The power loss is measured with a Single Sheet Tester (150 × 150 mm2). Each type of treatment resulted in a power loss reduction of 15–35% at peak induction 1.5 T and frequency 50 Hz. However, only the scribing and the ablation improved also the apparent permeability. In this work, the laser energy parameters are used to estimate the laser impact on the heat affected zone, the groove depth, the induced thermal stress, and on the internal properties of a magnetic behavioral model: static permeability and dynamic magnetization property [3].

    关键词: Groove depth,Heat affected zone,GO laminations,Induced thermal stress,Laser treatment,Magnetic properties

    更新于2025-09-23 15:19:57

  • Groove Depth Detection Method Base on the Line Laser Vision Measurement on Cement Concrete Pavement

    摘要: The groove depth has a decisive influence on the anti-sliding performance of cement concrete pavement, and it also plays an important role on the noise of cement concrete pavement. Aiming the shortcomings of traditional measurement methods of groove depth detection on the cement concrete pavement, a measurement method base on the structure light vision model was proposed. This method was realized by that the groove depth was obtained by 3D coordinate of the light strip according to the camera model and the structure light plane equation. A new algorithm based on double 2D plane pane target was proposed as the key step of this method.

    关键词: groove depth,line laser vision,structure light vision model,cement concrete pavement

    更新于2025-09-23 15:19:57

  • Deep learning-based roadway crack classification using laser-scanned range images: A comparative study on hyperparameter selection

    摘要: In recent years, deep learning-based crack detection methods have been widely explored and applied due to their high versatility and adaptability. In civil engineering applications, recent research on crack detection through deep convolutional neural network (DCNN) includes road pavement crack detection, bridge inspection, defects detection in shield tunnel lining, etc. Despite the increasing popularity of DCNN on crack detection, many challenges have yet to be properly addressed. For crack detection using three-dimensional (3D) range (i.e., elevation) images, disturbances such as surface variation can negatively affect the detection performance. Besides, some typical non-crack patterns such as grooves can be easily misidentified as cracks, i.e., false positives. Another issue lies in the selection of hyperparameters related with the design of a DCNN architecture. For example, the hyperparameters which are related with network structure (e.g., kernel size, network depth and width) and training (e.g., mini-batch size and learning rate) can impact the network performance to a significant extent. Therefore, they need to be properly determined for optimal performance. However, for deep learning-based roadway crack classification using laser-scanned range images, a comprehensive discussion on the hyperparameter selection/tuning has not been thoroughly performed. This study develops a hyperparameter selection process involving a series of experiments on laser-scanned range images with high diversities, investigating the optimal joint hyperparameter configuration on network structure and training for DCNN-based roadway crack classification. In a comparative study, 36 DCNN architectures with varying layouts are developed for crack classification. These architecture candidates differ in kernel sizes (e.g., 3 × 3, 7 × 7, and 11 × 11), network depths (from 5 to 8 weight layers), and widths (from 16 to 96 kernels in each convolutional layer). The 7-layer DCNN with constant 7 × 7 kernels and increasing network widths yields the highest classification performance among the proposed 36 DCNN classifiers, which may be because it can best reflect the complexity of the acquired laser-scanned roadway range images. Once the optimal architecture layout is determined, further discussion on the selection of min-batch sizes, learning rates, dropout factor and leaky rectified linear unit (LReLU) factor is performed. Experimental results show the optimal architecture with associated training configuration can achieve consistent and accurate performance, under the contamination of surface variations and grooved patterns in laser-scanned range images. Discussion on the hyperparameter selection can provide insights for the development of DCNN in similar applications using laser-scanned range images.

    关键词: Roadway crack,Groove,Laser-scanned range image,Hyperparameter selection,Deep convolutional neural network

    更新于2025-09-23 15:19:57

  • Groove Formation in Glass Substrate by a UV Nanosecond Laser

    摘要: This study reports the laser grooving of glass. In this study, an ultraviolet (UV) nanosecond laser is used to produce grooves in soda lime glass by varying laser power, scan speed, pulse repetition rate, and number of scans. The threshold power density to generate damage on glass surface is found to be ~6.37 × 108 W/cm2. According to the result of a single laser scan, at a high laser power and low scan speed, material removal does not nearly occur, and only volume melting underneath the glass surface and large thermal crack are induced. With the decreasing laser power and increasing scan speed, a groove with a smooth surface is formed owing to the melting-dominant material removal process. The groove of rough surface morphology is produced with the further increase of the scan speed due to shattering induced by shock wave. Under this condition, it is found that either small cracks are produced or a crack-free groove is obtained. In this study, the fabrication of the microchannel for bio-chip application is also attempted by multiple laser scans. The near rectangular-shaped and crack-free groove (width × depth: ~220 μm × ~500 μm) with quite a smooth surface is fabricated by the multiple laser scans with a non-zero scan spacing.

    关键词: ultra violet (UV),laser grooving,nanosecond laser,glass,groove

    更新于2025-09-19 17:13:59

  • Fabrication of grooves on polymer-derived SiAlCN ceramics using femtosecond laser pulses

    摘要: In this study, grooves were fabricated on the surface of fully dense polymer-derived SiAlCN ceramics. Industrial femtosecond laser source was used at wavelength of 1030 nm with pulse duration of 290 fs and repetition rate of 100 kHz. Moreover, comprehensive study was carried out to evaluate the influence of scan speed and energy fluence on grooves quality, including the heat-affected zone around the laser-machined grooves, microstructures of laser-irradiated surface, and cross-section morphology of grooves. A series of grooves with width in the range of 30–80 μm and depth below 280 μm was successfully fabricated using femtosecond laser pulse. Laser parameters were optimized to obtain grooves with satisfying surface quality. Furthermore, formation and disappearance of laser-induced periodic surface structures were systematically investigated. This study proposes fabrication of grooves on SiAlCN ceramics via laser processing, which provides precise method for fabrication of microstructure with fascinating properties.

    关键词: Laser-induced periodic surface structures,Polymer-derived ceramics,Femtosecond laser pulse,Groove

    更新于2025-09-19 17:13:59

  • [IEEE 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - HangZhou, China (2018.9.5-2018.9.7)] 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - Investigation of Ultra-wideband Ridged Half-Mode Substrate-Integrated Waveguide Coupler

    摘要: In this paper, a novel ultra wideband (UWB) 3-dB coupler at X and Ku band based on ridged half-mode substrate integrated waveguide (RHMSIW) and embedded the shape of metal groove is designed, fabricated, and measured, which is widely used in microwave and millimeter wave circuits. The structural parameters of new UWB RHMSIW 3-dB coupler with three cascading metal groove cells are analyzed. The structure is simulated with a relative bandwidth of 48% at the center frequency of 15 GHz. The measured results show that the proposed RHMSIW coupler keeps good performance of the HMSIW coupler. Simulated results are in agreement with the measured results. The results show that the novel UWB RHMSIW 3-dB coupler can provide better performance and have a smaller size compared with reported couplers, which illustrates its application in the wideband millimeter wave systems.

    关键词: metal groove,ultra wideband,coupler,Ridged half-mode substrate integrated waveguide (RHMSIW)

    更新于2025-09-19 17:13:59