- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Multifunctional and Recyclable TiO2 Hybrid Sponges for Efficient Sorption, Detection, and Photocatalytic Decomposition of Organic Pollutants
摘要： Developing techniques for monitoring and removing organic pollutants such as solvents and dyes in environmental media is a very important task nowadays. To get rid of the pollutants, efficient materials that can sorb, detect, and decompose such compounds have been consistently sought after. Herein, we demonstrate a simple and inexpensive method to fabricate eco-friendly multifunctional and recyclable TiO2 hybrid sponges composed of a polydimethylsiloxane (PDMS) network and functional nanoparticles. Water-soluble crystals were used to construct porous templates and TiO2 nanoparticles were additionally integrated into the templates where liquid PDMS was filled. After curing the PDMS, the TiO2 integrated hybrid sponges were finally obtained by dissolving the templates with water. By using the fabricated hybrid sponges, sorbed organic pollutants were qualitatively detected via molecular-specific Raman signals. Furthermore, we showed the recyclability by achieving photocatalytic decomposition of the sorbed pollutants induced by the TiO2 nanoparticles. These results are instructive for further applications and also contribute toward solving problems relating to environmental pollution.
关键词： TiO2 hybrid sponge,Raman detection,photocatalytic decomposition,organic pollutants,efficient sorption
更新于2025-11-25 10:30:42
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Color image encryption method based on 2D-variational mode decomposition
摘要： In order to reduce the correlation between adjacent pixels in a plaintext image, and to solve the small key space problem of image encryption algorithms when a low-dimension chaotic map is used, a new encryption method for color images is proposed based on two-dimensional variational mode decomposition (2D-VMD) combined with eight-dimensional (8D) hyper-chaotic systems. 2D-VMD decomposes R, G and B components of a color image respectively. The 8D hyper-chaotic system is constructed by means of variable coupling. After improving and combining the original sequences obtained by iterating the system, two groups of key sequences associated with the plain-image are obtained. One group is used to scramble each mode image obtained by 2D-VMD; the other is used to replace the pixel values of the scrambled mode images. For different mode images, different key sequences are adopted. The encrypted images whose number is equal to the number of the modes can then be obtained. The experimental results show that, compared with the existing methods, the correlation coefficients between the pixels in the spatial domain of the plain-image can be reduced by 2D-VMD, as it’s more difficult to crack. In addition, the encryption method has better statistical and differential characteristics, as well as large enough key space, and better plain-image sensitivity.
关键词： Encryption method,Image decomposition,Two-dimensional variational mode decomposition,Color image,Hyper-chaotic system
更新于2025-09-23 15:23:52
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[IEEE 2018 17th International Conference on Ground Penetrating Radar (GPR) - Rapperswil, Switzerland (2018.6.18-2018.6.21)] 2018 17th International Conference on Ground Penetrating Radar (GPR) - Noise suppression of GPR data using Variational Mode Decomposition
摘要： Ground penetrating radar (GPR) has been used in the many aspects, such as civil engineering and the earth sciences. And the analysis and noise suppression of GPR data have always been the research focus. In this study, a new self-adaptive time-frequency decomposition tool called the variational mode decomposition (VMD) is introduced. We use the VMD method to derive a set of stationary sub-components, and based on the decomposition, we separate the valid signals and the components which are corresponded to the noise. One trace of GPR data are given to test the effect of the VMD decomposition, and the empirical mode decomposition (EMD) is also employed as a comparison. And a primary noise-suppression method based on the VMD scheme is also proposed. The application of the field GPR data further demonstrates the better performance of the proposed method in both noise suppression and the retention of geophysical events.
关键词： ground penetrating radar (GPR),mode decomposition,variational mode decomposition (VMD),noise reduction or suppression
更新于2025-09-23 15:23:52
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Mixed Total Field/Scattered Field-Based Discontinuous Galerkin Frequency-Domain Method for Subsurface Sensing
摘要： To model the responses of electromagnetic surveys for geophysical subsurface sensing, a mixed total field/scattered field-based discontinuous Galerkin frequency-domain (TF/SF DGFD) method is proposed in this paper. The proposed TF/SF DGFD method is implemented at a subdomain level based on the domain decomposition technique. Different subdomains can employ either the TF DGFD framework or the SF DGFD framework, which are then coupled through the Riemann transmission condition. To balance the computation efficiency and accuracy for practical applications, the proposed method prefers to using the SF DGFD framework for subdomains with sources and using the TF DGFD framework for the remaining subdomains. At the interfaces between total field and scattered field subdomains, the Riemann transmission condition is slightly modified by incorporating the background fields due to the physically imposed sources in the background media. In this way, the proposed method only requires surface integrals of the background fields as extra overhead instead of elementwise integration of the scattering objects for the purely scattered field-based method, which can improve the computational efficiency. Also, it is more accurate than the purely TF DGFD method given the same mesh. Numerical examples are studied to examine the performance of the proposed method, which is proven to have better accuracy than the TF DGFD method. The TF/SF DGFD method will facilitate modeling of electromagnetic surveys under complicated geophysical environments for subsurface sensing.
关键词： scattered field,Anisotropy,domain decomposition,discontinuous Galerkin frequency-domain (DGFD) method,total field,subsurface sensing
更新于2025-09-23 15:23:52
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Preparation of Bi<sub>2</sub>Gd<sub>1</sub>Fe<sub>5</sub>O<sub>12</sub> magnetic garnet films showing Faraday rotation of 36.3 deg./μm on glass substrates by metal organic decomposition method
摘要： We fabricated the Bi2Gd1Fe5O12 thin films on glass substrates with the Gd3Fe5O12 buffer layer by the metal organic decomposition (MOD) method. We found an optimum thickness of the Gd3Fe5O12 buffer layer and annealing temperature for crystallization giving the maximum Faraday rotation. The optimum sample showed Faraday rotation of as high as 36.3 deg./μm at the wavelength λ = 500 nm, which is 23 times larger than the sample without the Gd3Fe5O12 buffer layer, and as high as 90.1% of the single crystalline Bi2Gd1Fe5O12 thin films on an (111) SGGG single crystal substrate. These results are promising for applications in optical waveguide isolators and magneto-optic spatial light modulators.
关键词： metal organic decomposition,crystallization process,Faraday rotation,photonic integrated circuits,magnetic garnet
更新于2025-09-23 15:23:52
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Image Denoising Using Block-Rotation-Based SVD Filtering in Wavelet Domain
摘要： This paper proposes an image denoising method using singular value decomposition (SVD) with block-rotation-based operations in wavelet domain. First, we decompose a noisy image to some sub-blocks, and use the single-level discrete 2-D wavelet transform to decompose each sub-block into the low-frequency image part and the high-frequency parts. Then, we use SVD and rotation-based SVD with the rank-1 approximation to filter the noise of the different high-frequency parts, and get the denoised sub-blocks. Finally, we reconstruct the sub-block from the low-frequency part and the filtered the high-frequency parts by the inverse wavelet transform, and reorganize each denoised sub-blocks to obtain the final denoised image. Experiments show the effectiveness of this method, compared with relevant methods.
关键词： singular value decomposition,threshold denoising,structural similarity index,position,peak signal-to-noise ratio,image denoising
更新于2025-09-23 15:23:52
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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) - A Novel Approach to Underwater De-Scattering Based on Sparse and Low-Rank Matrix Decomposition
摘要： The images captured in turbid water suffer from severe visual degradation due to the dramatic scattering effects caused by abundant large suspended particles. This paper propose a novel underwater image de-scattering approach with low complexity, which can separate the scattering component from the image by using the sparse and low-rank matrix decomposition. The experimental results show that the proposed approach can enhance the global image contrast effectively. Additionally, this approach does not require specialized hardware or prior knowledge about the underwater environment; it is suitable for the underwater imaging system in real time.
关键词： turbid water,low-rank matrix decomposition,de-scattering,underwater image
更新于2025-09-23 15:23:52
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Structural and Diffuse Reflectance Study of Cr-Doped ZnO Nanorod-Pigments Prepared via Facile Thermal Decomposition Technique
摘要： Ceramic coloured nanopigments are promising for commercial cool paint applications. This study was carried out to examine the near infrared (NIR) reflectivity of Cr-doped ZnO nanopigments prepared by simple thermal decomposition of zinc acetate dihydrate and chromium(III) acetate hydroxide as precursors of Zn and Cr, respectively. XRD, FTIR and SEM have been used to characterize the microstructure and morphological properties of the synthesized nanopigments. The obtained results referred to ZnO wurtzite hexagonal structure in absence of other ZnO phases or any phases based on chromium. The obtained particles of the investigated samples are uniform rod-like shape with average diameter about 50 nm. The diffuse reflectance measurements exhibited the decrease in NIR reflectance with increasing Cr content. The sample with lower content of Cr, 0.5 wt% of Cr precursor to Zn precursor, exhibited a maximum value of NIR solar reflectance (R*) of 53.1% with respect to the other doped samples. The optical energy gap (Eg) of the investigated nanopigments were calculated using diffuse reflectance spectrum in view of Kubelka–Munk assumptions and the obtained average value of Eg is 3.219 eV with small standard deviation ± 0.015 eV.
关键词： Thermal decomposition technique,ZnO,Structure and optical properties,Pigments
更新于2025-09-23 15:23:52
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A new solar hybrid clean fuel-fired distributed energy system with solar thermochemical conversion
摘要： This paper proposes a new solar hybrid clean fuel-fired distributed energy system to increase the system thermodynamic efficiency and save fossil fuel, in which solar energy is upgraded into high-level chemical energy of syngas (H2 and CO) by integrating the solar-driven methanol decomposition based thermochemical conversion. Solar energy, in the form of chemical energy of the generated syngas, is steadily stored and utilized to drive the distributed energy system to generate power, heat and cooling. The double-axis tracking parabolic trough solar collector is deployed to the proposed system to reduce the cosine loss of solar energy. The incorporation of the solar thermochemistry and double-axis solar concentrator technologies leads to a significant improvement in the solar energy utilization efficiency and the off-design performances under varying solar irradiations. With the integration of solar energy utilization and tri-generation, the proposed system achieves a high net solar-to-electric efficiency, 24.66%, and results in high primary energy ratio, 83.86%, exergy efficiency, 38.81%, and carbon emission saving rate, 51.43%. The proposed system is deployed to an office building to study the operation strategies and annual thermo-economy performances, and competitive off-design performances and economy performances are achieved. The research findings open up a new avenue towards the efficient utilization modes of clean fuel and solar energy.
关键词： Distributed energy system,Solar fuel,Solar thermochemistry,Methanol decomposition,Tracking strategy
更新于2025-09-23 15:23:52
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DeepPrimitive: Image decomposition by layered primitive detection
摘要： The perception of the visual world through basic building blocks, such as cubes, spheres, and cones, gives human beings a parsimonious understanding of the visual world. Thus, efforts to find primitive-based geometric interpretations of visual data date back to 1970s studies of visual media. However, due to the difficulty of primitive fitting in the pre-deep learning age, this research approach faded from the main stage, and the vision community turned primarily to semantic image understanding. In this paper, we revisit the classical problem of building geometric interpretations of images, using supervised deep learning tools. We build a framework to detect primitives from images in a layered manner by modifying the YOLO network; an RNN with a novel loss function is then used to equip this network with the capability to predict primitives with a variable number of parameters. We compare our pipeline to traditional and other baseline learning methods, demonstrating that our layered detection model has higher accuracy and performs better reconstruction.
关键词： biologically inspired vision,primitive detection,deep learning,layered image decomposition
更新于2025-09-23 15:23:52