- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Optimization of Residual Stresses in Laser-Mixed WC(Co, Ni) Coatings
摘要： A ternary mixture of tungsten carbide (WC), cobalt (Co), and nickel (Ni) powders is prepared to form ceramic-metal composite coatings employed for laser cladding of 40Cr steel. This coating is investigated using the mixture design to evaluate the influence of its ratios on the residual stresses in the clads. The WC/Co/Ni ternary mixture exhibits higher residual stresses than those of the Co/Ni or WC/Ni binary mixtures, except for the WC/Co one. Single WC, Co, or Ni designs illustrate a high sensitivity of residual stresses, cracks pass through the interior of WC particles rather than around them, and the cracks mostly propagate along the eutectic phases at 50%Co–50%WC. A reduced special quartic model in the mixture design exhibits excellent fit, predicted and experimental values of residual stresses for these laser clads are in good agreement.
关键词： residual stress optimization,mixture,reduced special quartic model,tungsten carbide
更新于2025-11-28 14:24:20
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White light emission from a mixture of silicon quantum dots and gold nanoclusters and its utilities in sensing of mercury( <scp>ii</scp> ) ions and thiol containing amino acid
摘要： White light emitting mixture (WLEM) was produced by controlled mixing of blue emitting silicon quantum dots (Si QDs) and orange red emitting gold nanoclusters (Au NCs). The chromaticity color co-ordinate of the WLEM studied using CIE (Commission Internationale del'Eclairage) diagram was found to be (0.33, 0.32), which was very close to that of perfect white light emitting source. The WLEM can also be achieved in the form of gel, solid and film with nearly the same CIE co-ordinates which enhances its utility as white light-emitting source in solid state devices. The reversible and thermo-responsive behaviour of the WLEM broadens its application in thermal sensing. Furthermore, the system was found to be showing fast, sensitive and selective detection of Hg2+ ions and thiol containing amino acid cysteine.
关键词： Hg2+ ions,white light emitting mixture,silicon quantum dots,cysteine,gold nanoclusters
更新于2025-11-20 15:33:11
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Effect of O <sub/>2</sub> Flow Rate on Properties of Mn–SnO <sub/>2</sub> /Ag/Mn–SnO <sub/>2</sub> Multilayer Film
摘要： Multilayer films with Mn–SnO2 (MTO)/Ag/Mn–SnO2 (MTO) hybrid structure were prepared on a flexible polyethylene terephthalate (PET) substrate using a DC/RF sputtering system at room temperature. The optical, electrical, and structural properties of the thus-synthesized multilayer films were systematically investigated as a function of the O2/(Ar + O2) flow rate. The transmittance of the MTO/Ag/MTO multilayer films at 550 nm increased gradually from 83.1% to 87.9% and the sheet resistance (Rs) of the multilayer films increased from 6.3 to 9.8 Ω/sq upon increasing the O2/(Ar + O2) flow rate. The highest figure of merit (ΦTC) of the MTO/Ag/MTO multilayer film was 45.7 × 10?3 Ω?1 at an O2/(Ar + O2) flow rate of 2.8%. X-ray photoelectron spectra of multilayer films obtained with different O2/(Ar + O2) flow rates showed no noticeable variation.
关键词： Sheet Resistance,Figure of Merit,Transmittance,Gas Mixture Rate,Oxide/Metal/Oxide Structure
更新于2025-09-23 15:23:52
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An image thresholding approach based on Gaussian mixture model
摘要： Image thresholding is an important technique for partitioning the image into foreground and background in image processing and analysis. It is difficult for traditional thresholding methods to get satisfactory performance on the noisy and uneven grayscale images. In this paper, we propose an image thresholding approach based on Gaussian mixture model (GMM) to solve this problem. GMM assumes that image is a mixture of two unknown parameters’ Gaussian distributions, which corresponds to foreground and background, respectively. Based on this assumption, we adopt expectation maximization algorithm with a simple initialization strategy to estimate the statistical parameters and utilize Bayesian criteria to generate the binary map. Furthermore, we calculate the posterior probabilities in consideration of neighborhood effect to achieve good performance on noisy and uneven grayscale images. Experimental results conducted on the synthetic and real images demonstrate the effectiveness of the proposed method.
关键词： Image thresholding,Gaussian mixture model,EM algorithm,Neighborhood information
更新于2025-09-23 15:23:52
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Electrically tuned microwave CP cross slot patch antenna using liquid crystal technology
摘要： The rapid progress in material science and electronic technology is great possibility in designing reconfigurable wireless devices which are frequency tunable, flexible and consume low energy. In this paper, the anisotropic propriety of a new liquid crystal mixture 'GT3-23001' in their nematic phase are exploited for designing tunable circular polarized cross slot patch antenna for WLAN applications. Reconfiguration of frequency response is controlled through an electrical external command. The proposed reconfigurable antenna based on liquid crystal satisfies a continuous frequency tuning of 15.83% with a global bandwidth of around 467.92 MHz (19.5%). to validate this novel mixture of liquid crystal, the simulated results are compared with the measured data and a good agreement is noticed.
关键词： liquid crystal mixture,Material science,tunable patch,circular polarized,reconfigurable,frequency tuning
更新于2025-09-23 15:23:52
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[IEEE 2018 Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA) - Poznan, Poland (2018.9.19-2018.9.21)] 2018 Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA) - Hardware implementation of the Gaussian Mixture Model foreground object segmentation algorithm working with ultra-high resolution video stream in real-time
摘要： In this paper a hardware implementation of the Gaussian Mixture Model algorithm for background modelling and foreground object segmentation is presented. The proposed vision system is able to handle video stream with resolution up to 4K (3840x2160 pixels) and 60 frames per second. Moreover, the constraints caused by memory bandwidth limit are also discussed and a few different solutions to tackle this issue have been considered. The designed modules have been verified on the ZCU102 development board with Xilinx Zynq UltraScale+ MPSoC device. Additionally, the computing performance and power consumption have been estimated.
关键词： FPGA,4K video,background modelling,real-time processing,GPU,Gaussian Mixture Model,foreground object segmentation
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Adaptive Hyperspectral Mixed Noise Removal
摘要： This paper proposes a new denoising method for hyperspectral images (HSIs) corrupted by mixtures (in a statistical sense) of stripe noise, Gaussian noise, and impulsive noise. The proposed method has three distinctive features: 1) it exploits the intrinsic characteristics of HSIs, namely, low-rank and self-similarity; 2) the observation noise is assumed to be additive and modeled by a mixture of Gaussian (MoG) densities; 3) the inference is performed with an expectation maximization (EM) algorithm, which, in addition to the clean HSI, also estimates the mixture parameters (posterior probability of each mode and variances). Comparisons of the proposed method with state-of-the-art algorithms provide experimental evidence of the effectiveness of the proposed denoising algorithm.
关键词： expectation maximization,low-rank,mixed noise,self-similarity,Denoising,mixture of Gaussians,hyperspectral images
更新于2025-09-23 15:22:29
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Parameter Estimation for Rayleigh-Pearson Mixture Model Based on Expectation-Maximization Algorithm
摘要： In this paper I propose a mixture distribution model with Rayleigh and Pearson distributions in order to represent the statistics of the reverberation. In addition the paper studies a parameter estimation method for the mixture distribution. As a preliminary step the parameter estimation of Pearson distribution is studied. Then the method of the parameter estimation is derived in the Rayleigh-Pearson mixture model based on the expectation-maximization (EM) technique. Simulation results have demonstrated that the parameter estimation method provides adequate performance.
关键词： Pearson distribution,parameter estimation,EM algorithm,mixture distribution
更新于2025-09-23 15:22:29
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Unsupervised Segmentation of Spectral Images with a Spatialized Gaussian Mixture Model and Model Selection
摘要： In this article, we describe a novel unsupervised spectral image segmentation algorithm. This algorithm extends the classical Gaussian Mixture Model-based unsupervised classification technique by incorporating a spatial flavor into the model: the spectra are modelized by a mixture of K classes, each with a Gaussian distribution, whose mixing proportions depend on the position. Using a piecewise constant structure for those mixing proportions, we are able to construct a penalized maximum likelihood procedure that estimates the optimal partition as well as all the other parameters, including the number of classes. We provide a theoretical guarantee for this estimation, even when the generating model is not within the tested set, and describe an efficient implementation. Finally, we conduct some numerical experiments of unsupervised segmentation from a real dataset.
关键词： Spectral images,Gaussian Mixture Model,Model selection,Spatial information,Unsupervised segmentation
更新于2025-09-23 15:22:29
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Highly -sensitive near infrared luminescent nanothermometers based on binary mixture
摘要： We propose a simple strategy to obtain a luminescence intensity ratio nanothermometer operating in the near infrared range (1000 – 1700 nm) by use of binary mixtures of lanthanide doped Y2O3 selected as 1%Ho - Y2O3 + 1%Er - Y2O3 and 1%Ho - Y2O3 + 1%Nd - Y2O3. All nanoparticles were synthetized by citrate complexation method and thermally annealed at 800 °C. The temperature evolution of the emission properties was monitored in the range of 297 – 472 K and analyzed in terms of emission shape, intensity, dynamics, excitation wavelength, acquisition mode and weight ratio of the binary mixture. A maximum relative sensitivity of 1%K-1 at 297 K was recorded for the 3:1 weight ratio Ho – Y2O3 + Er – Y2O3 binary mixture upon excitation at 536.8 nm. For the more appropriate excitation wavelength for bioimaging applications at 649.7 nm, a relative sensitivity of 0.55 - 0.6 % K-1 was recorded in the relevant physiological temperature range (300 -320 K) for the 3:1 weight ratio Ho – Y2O3 + Er – Y2O3 binary mixture. To the best of our knowledge, our study also represents a first report on the near -infrared luminescence (around 1200 nm) lifetime thermometry for a Ho doped nanoparticle. Comparison with the literature demonstrates that our system represents a promising near-infrared thermometer, with a non-sophisticated and reproducible configuration that is open to multiple optimization routes.
关键词： Lifetime thermometry,Binary mixture,lanthanide doped Y2O3,Near infrared luminescence,Self-referenced nanothermometry
更新于2025-09-23 15:22:29