34 research outputs found

    Intelligent methods for optimization design of lightweight fiber-reinforced composite structures: A review and the-state-of-the-art

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    As the application of lightweight fiber-reinforced composite structures reaches an unprecedented scale in industry, design technology for composite structures becomes crucial for enhancing performance, improving productivity, and reducing cost. In recent years, the rapid development of intelligent technology, such as big data, deep learning, and machine learning, has promoted the development of design technology. However, the current situation and intellectualization of the design technology is not well summarized. This paper reviews the advance in design technologies for fiber-reinforced composite structures, including prediction and optimization methods for composite properties. Then, their intellectualization development is overviewed. Finally, the development trend of intelligent design technologies and intelligent composite structures are discussed. This work can provide a reference for researchers in the related field

    Comparative genomics reveals the hybrid origin of a macaque group

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    Although species can arise through hybridization, compelling evidence for hybrid speciation has been reported only rarely in animals. Here, we present phylogenomic analyses on genomes from 12 macaque species and show that the fascicularis group originated from an ancient hybridization between the sinica and silenus groups ~3.45 to 3.56 million years ago. The X chromosomes and low-recombination regions exhibited equal contributions from each parental lineage, suggesting that they were less affected by subsequent backcrossing and hence could have played an important role in maintaining hybrid integrity. We identified many reproduction-associated genes that could have contributed to the development of the mixed sexual phenotypes characteristic of the fascicularis group. The phylogeny within the silenus group was also resolved, and functional experimentation confirmed that all extant Western silenus species are susceptible to HIV-1 infection. Our study provides novel insights into macaque evolution and reveals a hybrid speciation event that has occurred only very rarely in primates

    Anti-Wear Design of the Knot-Tripping Mechanism and Knot-Tying Test for the Knotter

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    Aiming to solve the problem of knot-tripping failure caused by severe wear between the spherical roller and planar cam of the knotter, this paper first establishes a calculation model of the spatial cam contour surface. The knot-tripping mechanism in the knotter is designed as a line-contact curved-surface cam mechanism, with the cutter arm swinging in accordance with sinusoidal acceleration. The design significantly reduces the contact stress between the cam and the roller, compared to the original knot-tripping mechanism. Additionally, it eliminates the impact between the spherical roller and the planar cam. Based on the Archard model, the calculation model for cam-roller wear in the knot-tripping mechanism has been derived and utilized for wear calculation. The wear test results of the knot-tripping mechanism with an aluminum cam show that the curved cam has a wear amount that is 43%, 56%, 46%, and 37% lower than that of the planar cam after tying the knot 200 times, 600 times, 1300 times, and 2000 times, respectively. Under the condition that the twine tension is set to 120 N, and the rotation speed of the fluted disc is 60 rpm, the deviations between the calculated value and the measured value of the wear amount of the curved cam are 9.48%, 6.01%, 7.27%, and 9.95%, respectively. This validates the accuracy of the spatial cam wear model and the correctness of the curved cam design

    Engineering Ferroelectric HZO With n<sup>+</sup>-Si/Ge Substrates Achieving High 2<italic>P<sub>r</sub></italic>=84&#x00A0;<bold>&#x03BC;</bold>C/cm<sup>2</sup> and Endurance &#x003E;1E11

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    Metal-Ferroelectric-Metal (MFM) devices possessing high remanent polarizations ( 2Pr2P_{r} ) of 84 and 73 μ73~\mu C/cm2 are demonstrated with nearly epitaxially grown Hf0.5Zr0.5O2 (HZO) films on (001) n+-Si(3E19/cm 3^{3} ) and n+-Ge(3E20/cm 3^{3} ) substrates, respectively, which are higher than MFM devices with HZO films grown on amorphous SiO2 and partially crystallized TiN underlayers/substrates. The HZO superlattice films by sequential ZrO2/HfO2 plasma-enhanced atomic layer deposition (PEALD) process show high crystallinity in TEM images of all devices; however, the measured 2Pr2P_{r} values are quite different, ranging from 84 to 33μ33\mu C/cm2. The high-resolution scanning transmission electron microscopy (HR-STEM) images of HZO films on n+-Si and n+-Ge show the polarization axis of o-phase is well-aligned with the growth direction which is consistent with observed high 2Pr2P_{r} values. Much lower interfacial energy at o-phase/Si(Ge) interfaces than m-(t-)phase/Si(Ge) by density functional theory (DFT) calculations indicates that o-phase is greatly stabilized in the HZO films on n+-Si(Ge) substrates. Strong 2Pr2P_{r} of 51 and 47 μ47~\mu C/cm2 are measured after 1E9 and 1E11 endurance cycles for HZO films on n+-Si and n+-Ge substrates, respectively. This study shows epitaxial ferroelectric HZO films could be achieved by using small misfit substrates with the thermal budget as low as 450&#x00B0;C

    Prediction of new vertebral compression fracture within 3 years after percutaneous vertebroplasty for osteoporotic vertebral compression fracture: Establishment and validation of a nomogram prediction model.

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    New vertebral compression fractures (NVCF) are common in patients with osteoporotic vertebral compression fractures (OVCF) who have undergone percutaneous vertebroplasty (PVP). We sought to develop a nomogram prediction model for better identification and prevention of NVCF within 3 years after PVP in patients with OVCF. The demographic, clinical, and imaging data of patients who underwent PVP for OVCF between January 2010 and December 2019 were reviewed. Multivariate logistic regression analysis was used to screen for risk factors for NVCF within 3 years after PVP. A nomogram prediction model was then developed and validated to visually predict NVCF. The samples in the model were randomly divided into training and validation sets at a ratio of 7:3. Twenty-seven percent of patients experienced NVCF in other segments within 3 years after PVP. Older age, lower bone mineral density (BMD), smoking, lack of anti-osteoporosis therapy, and postoperative trauma were risk factors for NVCF. The area under the receiver operating characteristic curve suggested good discrimination of this model: training set (0.781, 95% confidence interval: 0.731-0.831) and validation set (0.786, 95% confidence interval: 0.708-0.863). The calibration curve suggested good prediction accuracy between the actual and predicted probabilities in the training and validation sets. The DCA results suggested that, when the probability thresholds were 0.0452-08394 and 0.0336-0.7262 in the training and validation set, respectively, patients can benefit from using this model to predict NVCF within 3 years after PVP. In conclusion, this nomogram prediction model that included five risk factors (older age, lower BMD, smoking, postoperative minor trauma, and lack of anti-osteoporosis treatment can effectively predict NVCF within 3 years after PVP. Postoperative smoking cessation, standard anti-osteoporosis treatment, and reduction in incidental minor trauma are necessary and effective means of reducing the incidence of NVCF

    Environmental Determinants of the Distribution of <i>Halophila beccarii</i> Ascherson in Hainan Island, China

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    This study presents the first record of the overall distribution of the seagrass Halophila beccarii Ascherson on the island of Hainan. Statistical and ecological methods were used to analyze the distribution of the species and the influence of environmental factors. Halophila beccarii was mainly distributed in the northwest and southeast of Hainan, in lagoons with a total area of 20.981 km2, including the largest H. beccarii area in China covering approximately 9.58 km2 in Xiaohai, Wanning; there were also 4.89 km2 in Xinying Bay, Danzhou, approximately 2.20 km2 in Huachang Bay, Chengmai, 1.88 km2 in Dongzhai Port, Haikou, 0.95 km2 in Xinying Port, Lingao, approximately 0.668 km2 in Laoyehai, Wanning, approximately 0.363 km2 in Hongpai, approximately 0.23 km2 in Maniao, and approximately 0.22 km2 in Huanglong Port, Lingao. The average coverage of H. beccarii measured at 7.08–56.33%, the density of stem and branch was 487.47–20,167.1 ind/m2, and the biomass measured at 1.57–112.94 gDW/m2. The growth distribution was mainly influenced by habitat type and, to a lesser extent, by tidal branching channels, heavy metal content (Cu, Pb, Cr, Zn) in the marine environment, and human activities in adjacent coastal areas

    Inducing factors and deformation mechanism of the Zhangjiacitang landslide in the Three Gorges Reservoir Area

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    Abstract Landslides are the most widely distributed geological hazards in the Three Gorges Reservoir Area (TGRA). Understanding the deformation mechanism and evolution of landslides is of great significance for their prevention and control. In this study, we focused on the Zhangjiacitang landslide, a typical bank landslide in the TGRA. We analyzed the relationship between landslide deformation and water level fluctuations and rainfall, based on accumulated displacement monitoring data, to clarify their triggering factors and deformation mechanism. The results show that the Zhangjiacitang landslide is a large-scale accumulation landslide. Under the influence of cyclic water level fluctuations and periodic rainfall, the accumulated displacement–time curve shows a “stepped” characteristic. Heavy rainfall emerged as the primary factor influencing the deformation of the Zhangjiacitang landslide, leading to substantial deformation throughout different periods. The deformation of the landslide exhibited a positive correlation with the intensity of rainfall. In contrast, the impact of water level changes on the landslide deformation was more intricate. A rapid water level drop (> 0.3 m/d) tended to intensify the landslide deformation, while the slow water level drop period (< 0.3 m/d) did not exhibit such an effect. This study emphasizes the need for closely monitoring the landslide status during heavy rainfall periods and rapid water level decline periods. The findings of this study provide a certain reference for landslide monitoring, early warning, prevention and control in the TGRA

    The complete chloroplast genome of Enhalus acodoides and its phylogenetic analysis

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    Complete chloroplast genome of Enhalus acodoides was obtained in this work. Circular mapping revealed that the complete chloroplast sequences of E. acodoides was 176,748 bp in length and had an overall GC content of 38.3%, encoded 132 genes which contained 86 protein-coding genes (PCGs), 38 transfer RNA genes (tRNA) and 8 ribosomal RNA genes (rRNA). The phylogenetic tree shows that E. acodoides had a closer relationship with Thalassia hemprichii in Hydrocharitaceae and its analysis will help better understand the evolution of Alismatales species
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