Fusion of Infrared and Visible Images Based on Three-Scale Decomposition and ResNet Feature Transfer.

Image fusion technology can process multiple single image data into more reliable and comprehensive data, which play a key role in accurate target recognition and subsequent image processing. In view of the incomplete image decomposition, redundant extraction of infrared image energy information and incomplete feature extraction of visible images by existing algorithms, a fusion algorithm for infrared and visible image based on three-scale decomposition and ResNet feature transfer is proposed. Compared with the existing image decomposition methods, the three-scale decomposition method is used to finely layer the source image through two decompositions. Then, an optimized WLS method is designed to fuse the energy layer, which fully considers the infrared energy information and visible detail information. In addition, a ResNet-feature transfer method is designed for detail layer fusion, which can extract detailed information such as deeper contour structures. Finally, the structural layers are fused by weighted average strategy. Experimental results show that the proposed algorithm performs well in both visual effects and quantitative evaluation results compared with the five methods.

Thermo-Viscoelastic Response of 3D Braided Composites Based on a Novel FsMsFE Method.

A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied.

An embodied energy perspective of urban economy: A three-scale analysis for Beijing 2002-2012 with headquarter effect.

As the typical characteristic of globalization, large-scale agglomeration of headquarters in urban economies exerts extensive cross-border trade links, and inevitably generates energy use outside their boundary. Therefore, studies about urban economies' energy use profiles should pay special attention to the tremendous energy transfers embodied in their trade connections along the whole supply chain. In this regard, a three-scale input-output model which distinguishes local, domestic and foreign activities is devised to reflect cross border embodied energy perspective for urban economies, with an intensive case study for Beijing during 2002-2012. The results show that domestic imports dominate Beijing's total embodied energy use, while local energy exploitation accounts for less than one-tenths of the final use. Regarding to energy use embodied in trade, headquarter effect contributes significantly to the rapid growth of embodied energy inflows and outflows. Embodied energy transfers induced by headquarter effect almost doubled in the case period. Different industries show distinct embodied energy redistribution evolution characteristics. Moreover, the complete source-to-sink budget is constructed, implying that coal use still dominates Beijing's total embodied energy inputs. Analysis in this study highlights the importance to consider the impacts of headquarter effect on Beijing's embodied energy use and redistribution pattern, pointing the potential room for policy implications aimed to realize collective and inclusive governance of global energy supply chain.

Highly Sensitive Wearable Pressure Sensors Based on Three-Scale Nested Wrinkling Microstructures of Polypyrrole Films.

Pressure sensors have a variety of applications including wearable devices and electronic skins. To satisfy the practical applications, pressure sensors with a high sensitivity, a low detection limit, and a low-cost preparation are extremely needed. Herein, we fabricate highly sensitive pressure sensors based on hierarchically patterned polypyrrole (PPy) films, which are composed of three-scale nested surface wrinkling microstructures through a simple process. Namely, double-scale nested wrinkles are generated via in situ self-wrinkling during oxidative polymerization growth of PPy film on an elastic poly(dimethylsiloxane) substrate in the mixed acidic solution. Subsequent heating/cooling processing induces the third surface wrinkling and thus the controlled formation of three-scale nested wrinkling microstructures. The multiscale nested microstructures combined with stimulus-responsive characteristic and self-adaptive ability of wrinkling morphologies in PPy films offer the as-fabricated piezoresistive pressure sensors with a high sensitivity (19.32 kPa-1), a low detection limit (1 Pa), an ultrafast response (20 ms), and excellent durability and stability (more than 1000 circles), these comprehensive sensing properties being higher than the reported results in literature. Moreover, the pressure sensors have been successfully applied in the wearable electronic fields (e.g., pulse detection and voice recognition) and microcircuit controlling, as demonstrated here.

Topographic scale-range synergy at the functional bone/implant interface.

We sought to explore the biological mechanisms by which endosseous implant surface topography contributes to bone anchorage. To address this experimentally, we implanted five groups of custom-made commercially pure titanium implants of varying surface topographical complexity in rat femora for 9 days; subjected them to mechanical testing; and then examined the interfacial bone matrix by electron microscopy. The five implant surfaces were prepared by combinations of dual acid etching and grit blasting the titanium substrates and, in some cases, modifying the created surfaces with the deposition of nanocrystals of calcium phosphate, which resulted in 10 samples per group. In parallel, we cultured rat bone marrow cells on surrogate implants constructed from polymer resin coated with the same calcium phosphate nanocrystals, and monitored the deposition of bone sialoprotein by transmission electron immunohisto-micrography. We found that implant samples modified with sub-micron scale crystals were bone-bonding, as described by the interdigitation of a mineralized cement line matrix with the underlying implant surface. The in vitro assay showed that bone sialoprotein could be deposited in the interstices between, and undercuts below, the nanocrystals. In addition, when mineralized, the cement line matrix globules occupied micron-sized pits in the implant surfaces, and in part obliterated them, creating an additional form of anchorage. Our results also showed that collagen, elaborated by the osteogenic cells, wrapped around the coarse-micron features, and became mineralized in the normal course of bone formation. This provided a mechanism by which coarse-micron implant features contributed to a functional interface, which we have previously described, that is capable of resisting the mechanical loading that increases as peri-implant bone matures. Thus, our findings provide mechanistic explanations for the biologically-relevant criteria that can be employed to assess the importance of implant surface topography at different scale-ranges.