990 research outputs found
Elasto-plastic finite element analysis of reinforced concrete T-shaped column frame joint
By the integral finite element analysis of elasto-plastic constitutive relationship, the process of crack formation and development of the T-shaped frame joint in reinforced concrete and its stress distribution under monotonic and low-cycle repeated loading were studied . The nonlinear constitutive relation of concrete and the failure mechanism of T-shaped column joint were further discussed. The work of this paper provides a reference to the design and construction of T-shaped column joints.Peer Reviewe
Image Superresolution Reconstruction via Granular Computing Clustering
The problem of generating a superresolution (SR) image from a single low-resolution (LR) input image is addressed via granular computing clustering in the paper. Firstly, and the training images are regarded as SR image and partitioned into some SR patches, which are resized into LS patches, the training set is composed of the SR patches and the corresponding LR patches. Secondly, the granular computing (GrC) clustering is proposed by the hypersphere representation of granule and the fuzzy inclusion measure compounded by the operation between two granules. Thirdly, the granule set (GS) including hypersphere granules with different granularities is induced by GrC and used to form the relation between the LR image and the SR image by lasso. Experimental results showed that GrC achieved the least root mean square errors between the reconstructed SR image and the original image compared with bicubic interpolation, sparse representation, and NNLasso
Surface terraces in pure tungsten formed by high-temperature oxidation
We observe large-scale surface terraces in tungsten oxidised at high
temperature and in high vacuum. Their formation is highly dependent on crystal
orientation, with only {111} grains showing prominent terraces. Terrace facets
are aligned with {100} crystallographic planes, leading to an increase in total
surface energy, making a diffusion-driven formation mechanism unlikely. Instead
we hypothesize that preferential oxidation of {100} crystal planes controls
terrace formation. Grain height profiles after oxidation and the morphology of
samples heat treated with limited oxygen supply are consistent with this
hypothesis. Our observations have important implications for the use of
tungsten in extreme environments.Comment: 10 pages, 4 figures & supplementar
Recent Advances in Heterogeneous Catalytic Hydrogenation of CO2 to Methane
With the accelerating industrialization, urbanization process, and continuously upgrading of consumption structures, the CO2 from combustion of coal, oil, natural gas, and other hydrocarbon fuels is unbelievably increased over the past decade. As an important carbon resource, CO2 gained more and more attention because of its converting properties to lower hydrocarbon, such as methane, methanol, and formic acid. Among them, CO2 methanation is considered to be an extremely efficient method due to its high CO2 conversion and CH4 selectivity. However, the CO2 methanation process requires high reaction temperatures (300–400°C), which limits the theoretical yield of methane. Thus, it is desirable to find a new strategy for the efficient conversion of CO2 to methane at relatively low reaction temperature, and the key issue is using the catalysts in the process. The advances in the noble metal catalysts, Ni-based catalysts, and Co-based catalysts, for catalytic hydrogenation CO2 to methane are reviewed in this paper, and the effects of the supports and the addition of second metal on CO2 methanation as well as the reaction mechanisms are focused
Low-Rank Tensor Completion Based on Bivariate Equivalent Minimax-Concave Penalty
Low-rank tensor completion (LRTC) is an important problem in computer vision
and machine learning. The minimax-concave penalty (MCP) function as a
non-convex relaxation has achieved good results in the LRTC problem. To makes
all the constant parameters of the MCP function as variables so that futherly
improving the adaptability to the change of singular values in the LRTC
problem, we propose the bivariate equivalent minimax-concave penalty (BEMCP)
theorem. Applying the BEMCP theorem to tensor singular values leads to the
bivariate equivalent weighted tensor -norm (BEWTGN) theorem, and we
analyze and discuss its corresponding properties. Besides, to facilitate the
solution of the LRTC problem, we give the proximal operators of the BEMCP
theorem and BEWTGN. Meanwhile, we propose a BEMCP model for the LRTC problem,
which is optimally solved based on alternating direction multiplier (ADMM).
Finally, the proposed method is applied to the data restorations of
multispectral image (MSI), magnetic resonance imaging (MRI) and color video
(CV) in real-world, and the experimental results demonstrate that it
outperforms the state-of-arts methods.Comment: arXiv admin note: text overlap with arXiv:2109.1225
Elastic strain associated with irradiation-induced defects in self-ion irradiated tungsten
Elastic interactions play an important role in controlling irradiation damage evolution, but remain largely unexplored experimentally. Using transmission electron microscopy (TEM) and high-resolution on-axis transmission Kikuchi diffraction (HR-TKD), we correlate the evolution of irradiation-induced damage structures and the associated lattice strains in self-ion irradiated pure tungsten. TEM reveals different dislocation loop structures as a function of sample thickness, suggesting that free surfaces limit the formation of extended defect structures that are found in thicker samples. HR-TKD strain analysis shows the formation of crystallographically-orientated long-range strain fluctuations above 0.01 dpa and a decrease of total elastic energy above 0.1 dpa
Amygdalin isolated from Amygdalus mongolica protects against hepatic fibrosis in rats
The aim of this research was to investigate the effect of amygdalin on hepatic fibrosis in rats. Amygdalin was purified and identified from the seeds of Amygdalus mongolica. Sprague Dawley rats in the control and model groups were administered water. Sprague Dawley rats were divided into the low-, middle-, and high-dose amygdalin groups that received 20, 40, and 80 mg kg–1 amygdalin, respectively. whereas the silymarin group was treated with 50 mg kg–1 silymarin. The control and model groups were administered water. Liver tissue analysis revealed significantly lower activities of ALT, AST, ALP, SOD, and MDA in the drug-treated groups compared to the model group. Serum analysis revealed significantly lower HYC and C-IV in the middle-dose amygdalin-treated group compared to the model group. The histopathological changes were less severe in the drug-treated groups as observed by the formation of pseudolobuli and decreased collagen fiber deposition. Hepatic fibrosis-related genes were expressed at significantly lower levels in the amygdalin-treated groups than in the model group. Amygdalin from A. mongolica represents a therapeutic candidate for hepatic fibrosis prevention and treatment
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