Search

Flexible hybrid electronics possess significant potential for applications in biomedical and wearable devices due to their advantageous properties of good ductility, low mass, and portability. However, they often exhibit a substantial disparity in elastic modulus between the flexible substrate and rigid components. This discrepancy can result in damage to the rigid components themselves and detachment from the substrate when subjected to tensile, bending, or other loads. Consequently, it diminishes the lifespan of flexible hybrid electronics and restricts their broader-scale application. Therefore, this paper proposes a polydimethylsiloxane (PDMS)/SiC functionally graded flexible substrate based on variable stiffness properties. Initially, ABAQUS simulation is employed to analyze how variations in stiffness impact the stress-strain behavior of PDMS/SiC functionally graded flexible substrates. Subsequently, we propose a multi-material 3D printing process for fabricating PDMS/SiC functionally graded flexible substrates and develop an advanced multi-material 3D printing equipment to facilitate this process. Tensile specimens with the functional gradient of PDMS/SiC are successfully fabricated and subjected to mechanical testing. The results from the tensile tests demonstrate a significant enhancement in the tensile rate (from 21.6% to 35%) when utilizing the PDMS/SiC functionally graded flexible substrate compared to those employing only PDMS substrate. Furthermore, the application of PDMS/SiC functional gradient flexible substrate exhibits remarkable bending and tensile properties in stretchable electronics and skin electronics domains. The integrated fabrication approach of the PDMS/SiC functionally graded flexible substrate structure presents a novel high-performance solution along with its corresponding 3D printing methodology for stretchable flexible electronics, skin electronics, and other related fields.

The persistence of extracellular antibiotic resistance genes (ARGs) in aquatic environments has attracted increasing attention due to their potential threat to public health and the environment. However, the fate of extracellular ARGs in receiving water remains largely unknown. This study investigated the influence of hematite nanoparticles, a widespread natural mineral, on the photodegradation of extracellular ARGs in river water. Results showed that under exposure to visible light, hematite nanoparticles, at environmental concentrations, resulted in a 3–5 orders of magnitude reduction in extracellular ARGs. This photodegradation of extracellular ARGs is shown to be facet-dependent; the (001) facet of hematite demonstrates a higher removal rate than that of the (100) facet, which is ascribed to its enhanced adsorption capability and higher hydroxyl radical (•OH) production. Density functional theory (DFT) calculations corroborate this finding, indicating elevated iron density, larger adsorption energy, and lower energy barrier of •OH formation on the (001) facet, providing more active sites and •OH generation for extracellular ARG interaction. Gel electrophoresis and atomic force microscopy analyses further confirm that the (001) facet causes more substantial damage to extracellular ARGs than the (100) facet. These findings pave the way for predicting the photodegradation efficiency of hematite nanoparticles with varied facets, thereby shedding light on the inherent self-purification capacity for extracellular ARGs in both natural and engineered aquatic environments.

Nonlinear numerical analysis for prefabricated shell wall structure is processed on this paper with the finite element software of ABAQUS. Nonlinear numerical analysis for prefabricated shell wall with vertical joint is processed firstly and numerical analysis results are found to be reasonable when compared with experimental results. Then the influence of factors such as shear strength of joint and axial compression ratio are conparatively analyzed. The results show that shear strength of joint has a greater influence on the bearing capacity and hysteretic performance of the structure and axial compression ratio also has a greater influence on the bearing capacity but less on the hysteretic performance.

The sucrose (0.045%) is added in the cement paste, the consistency of Ca2+ and OH- reduce little, the AFt has high solubility product, thus the AFt exists as gel like product which covers the surface of the clinker particles, the sucrose acts as a retarder. When the dosage of the sucrose is 0.24%, the sucrose poisons the hydration of C2S and C3S markedly, so the consistency of Ca2+ and OH- reduce sharply, the AFt has low solubility product, the needle like AFt form a hydration product network and accelerates the setting process, C2S and C3S cannot yield enough C-S-H, the strength development is baffled. It was supposed that there are two dosage threshold values of sucrose on the hydration process, 0.01% is a retardation threshold value accelerating the formation of Aft, while 0.2% is an acceleration threshold value poisoning the hydration of C3S and C2S.

This article did some non-contact measurement by laser triangulation principle on the A level hard road roughness, based on CCD imaging principle,used scanning galvanometer, which improved the measurement speed and surface measurement range, , drew the three-dimensional surface roughness profile curve by interpolation and fitting,It was in accordance with the standard range of A-road height spectrum. This measurement method have important guiding significance on the hard road roughness measurement and practice of the design of the relatively flat three-dimensional contours.