Microcrack formation and delamination growth are the main damage mechanisms in thefatigue of composites. They lead to significant stiffness loss, introduce stress concentrations andcan be the origin of subsequent damage events like buckling or fibre breakage, especially in case ofshear and compression stresses during load reversal. Fatigue experiments of carbon fibre reinforcedlaminates were conducted at several stress ratios and analysed in terms of crack and delaminationgrowth. These investigations were accompanied by microscopic imaging, digital image correlationand finite element modelling to take into account the effects of residual stresses and crack closure.It was found that residual stresses significantly change the local stress ratio in off-axis layers andlead to residual crack opening of inter fibre cracks. These cracks remain open and close under highcompression loadings only. Furthermore, crack formation under pulsating compression loadingturned out to be driven by residual stresses leading to perpendicular cracks as observed underpure tension loading. The experimental findings further confirm the severe detrimental effect oftension-compression loading on crack formation and delamination growth compared to pulsatingtension-tension or compression-compression loads.
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http://dx.doi.org/10.3390/ma12071153 | DOI Listing |
BMC Microbiol
December 2024
School of Environment and Resource, Xichang University, Xichang, 615000, China.
The extensive mining of bastnasite (CeFCO) has caused pollution of lanthanum (La), cerium (Ce), and fuorine (F) in the surrounding farmland soil, severely threatening the safety of the soil ecosystem. However, the interaction effects of various chemical fractions of La, Ce, and F on the composition of microbial communities are unclear. In our study, high-throughput sequencing was performed based on the pot experiments of four types of combined pollution soils, i.
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December 2024
Department of Mechanics, Xi'an University of Science and Technology, Xi'an, 710054, China.
Under confining pressure, rocks transition from brittle failure to plastic failure, and residual strength exists after complete failure. However, in the process of establishing rock damage constitutive models, the strength criteria used usually do not consider residual stress. In cold region engineering, the freeze-thaw effect caused by temperature changes should be considered in the constitutive model, and strength criteria should also be introduced.
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December 2024
School of Medicine, The First Affiliated Hospital of Xiamen University, Xiamen University, Xiamen, Fujian, China.
Platelets possess cancer-induced reprogramming properties, thereby contributing to RNA profile alterations and further cancer progression, while the former is considered a promising biosource for cancer detection. Hence, tumor-educated platelets (TEP) are considered a prospective novel method for early breast cancer (BC) screening. Our study integrated the data from 276 patients with untreated BC, 95 with benign disease controls, 214 healthy controls, and 2 who underwent mastectomy in Chinese and European cohorts to develop a 10-biomarker diagnostic model.
View Article and Find Full Text PDFJ Prosthet Dent
December 2024
Associate Chief Physician, Department of Prosthodontic, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Clinical Research Center for Oral Diseases of Zhejiang Province, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China. Electronic address:
Statement Of Problem: Endodontically treated teeth often require post-and-core restorations for structural support because of extensive hard tissue loss. Assessment of the effect of the residual dentin thickness on the biomechanical performance of these restorations is lacking.
Purpose: The purpose of this study was to evaluate the residual dentin thickness in mandibular premolars after post-and-core restorations using cone beam computed tomography (CBCT) and to analyze the stress distribution with finite element analysis (FEA).
Nanomaterials (Basel)
December 2024
Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China.
W-doped ZnO (WZO) films were deposited on glass substrates by using RF magnetron sputtering at different substrate bias voltages, and the relationships between microstructure and optical and electrical properties were investigated. The results revealed that the deposition rate of WZO films first decreased from 8.8 to 7.
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