In this paper,we perform two-layer high-throughput *** the first layer,which involves changing the crystal structure and/or chemical composition,we analyze selected Ⅲ-Ⅴ semiconductors,filled and unfilled skutterudit...
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In this paper,we perform two-layer high-throughput *** the first layer,which involves changing the crystal structure and/or chemical composition,we analyze selected Ⅲ-Ⅴ semiconductors,filled and unfilled skutterudites,as well as rock salt and layered *** second layer searches the full Brillouin zone(BZ)for critical points within 1.5 eV(1 eV=1.602176×10^(-19)J)of the Fermi level and characterizes those points by computing the effective *** introduce several methods to compute the effective masses from first principles and compare them to each *** approach also includes the calculation of the density-of-states effective masses for warped critical points,where traditional approaches fail to give consistent results due to an underlying non-analytic behavior of the critical *** demonstrate the need to consider the band structure in its full complexity and the value of complementary approaches to compute the effective *** also provide computational evidence that warping occurs only in the presence of degeneracies.
The management of Construction and Demolition Waste (CDW) poses significant environmental challenges in Saudi Arabia, exacerbated by rapid urbanization and the Giga Projects under Vision 2030. This study presents a Li...
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Topological textures in optics such as skyrmions and merons are increasingly studied for their potential functions in light–matter interactions,deep-subwavelength imaging,and ***,they were previously generated either...
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Topological textures in optics such as skyrmions and merons are increasingly studied for their potential functions in light–matter interactions,deep-subwavelength imaging,and ***,they were previously generated either in strongly confined guided waves or in paraxial *** has posed a significant challenge in constructing skyrmions in nonparaxial propagating waves due to the lack of symmetry-breaking in the optical field and difficulty in characterizing the full three-dimensional spin textures at the *** theoretically propose and experimentally demonstrate the generation of skyrmionic spin textures in nonparaxial light,where skyrmionic textures with a Bloch-type scheme,including isolated skyrmioniums,skyrmion,and meron lattices are generated in free *** introduce the interplay between the Hertz potentials to break the dual symmetry of light and build well-defined domains of *** experimentally realized the topological textures by applying a hybrid polarized optical vortex and observed the complete three-dimensional spin distributions by a dual-mode waveguide *** bridging the gap in the skyrmionic group,we present a topologic diagram,showing how spin–orbit coupling of light governs the spin *** findings offer new insights into optical quasiparticles and electron–photon correspondence,potentially facilitating advanced applications in optical metrology,sensing,and storage.
Scattering problems are important in describing light propagation in wide ranging media such as the atmosphere, colloidal solutions, metamaterials, glass ceramic composites, transparent polycrystalline ceramics, and s...
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Delaminations are a common damage mechanism that occurs on composite structures due to in-service impacts. Enclosed damages less than 50 mm in diameter are of particular interest for repair. Current practices for repa...
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ISBN:
(纸本)9781605956909
Delaminations are a common damage mechanism that occurs on composite structures due to in-service impacts. Enclosed damages less than 50 mm in diameter are of particular interest for repair. Current practices for repair of delaminations include: cut out of the damage and applying a patch or doubler to the cutout site, or injection using a repair resin. The use of a bonded doubler repair is more invasive and requires a cutout that acts as a stress concentration in the area of the repair. Injection repairs have traditionally been a faster, less expensive way to repair composite delaminations. However, the aerospace industry has not accepted injection repair as a strength restorative process. Questions about quantifying delamination internal contamination and ensuring percentage of repair resin fill within a delamination have been primary reasons why injection repairs have not been credited with strength restoration. Development of a new quantitative internal surface cleaning, preparation and repair process for delaminated composite materials is required to provide justification for strength restoration using injection repair. Fabricating representative local delaminations was performed with a modified end-notch flexure (ENF) test. A unidirectional 24-ply panel was fabricated to simulate damage to laminates. Intentional contamination was introduced into the induced delamination of each panel type. Contamination removal and surface preparation using solvent and atmospheric plasma cleaning were completed on the modified ENF coupon and verified utilizing in-line monitoring with Quantitative Gas Analysis (QGA) and post processing inspection with Fourier Transform Infrared Spectroscopy (FTIR). A modified low-viscosity injection resin was developed and utilized to repair the post-tested ENF coupons. The modified epoxy exhibited comparable shear strength characteristics to un-modified neat resin while achieving a >97% reduction in viscosity. Each ENF panel type was assessed f
Microplastics are a growing environmental concern, with a large body of evidence documenting substantial distribution of plastic material in virtually all environmental compartments. Countermeasures that help to bind,...
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Microplastics are a growing environmental concern, with a large body of evidence documenting substantial distribution of plastic material in virtually all environmental compartments. Countermeasures that help to bind, aggregate, or coalesce these distributed particles might result in lower human and animal exposures. Pressure sensitive adhesives (PSAs) have been identified as a viable microplastic (MP) capture mechanism with a range of potential use conditions. As with any countermeasure, there is a need to evaluate potential solutions in terms of collection efficiency, cost, ease of installation, etc. Expanding on our previous work, spray-coated PSAs were investigated as submerged surfaces as tools to assess MP binding in aqueous dispersions. Resins containing two differing molecular weights of poly(2-ethylhexyl acrylate) PSA (92k and 950k), and a 50:50 by weight mixture of the two resins were applied as spray-coated substrates to compare the effect of resin composition on MP-adhesive binding. Thin films of PSA (92k 6 ± 1 μm, 950k 4 ± 2 μm, 50:50 BD 6.5 ± 1 μm) were sprayed on borosilicate glass slides using a commercial air brush. Polydisperse nylon-12 particles varying in size from 15-30 µm in diameter were dispersed in deionized water at concentrations between 0.01 and 5 mg mL -1 and agitated under ambient conditions to assess adhesive binding as quantitative comparisons of microparticle capture. Mixed assays were also performed comparing binding of common MP species including polyethylene (50, 200 µm), polystyrene (10 µm), and polyester fibers (1000 µm) to understand how varying composition, size, and form factor affect adsorption. The glass slide method showed increasing linear trends of particle binding with increased adhesive exposure time and MP concentration. The lower molecular weight 92K adhesive had lower viscosity, higher wettability for microplastics but also led to a less stable adhesive film complicating analysis. As a field-deployable scheme for mi
Grip surfaces with tunable friction can actively modify contact conditions, enabling transitions between higher- and lower-friction states for grasp adjustment. Friction can be increased to grip securely and then decr...
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Grip surfaces with tunable friction can actively modify contact conditions, enabling transitions between higher-and lower-friction states for grasp adjustment. Friction can be increased to grip securely and then decre...
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ISBN:
(数字)9798331520205
ISBN:
(纸本)9798331520212
Grip surfaces with tunable friction can actively modify contact conditions, enabling transitions between higher-and lower-friction states for grasp adjustment. Friction can be increased to grip securely and then decreased to gently release (e.g., for handovers) or manipulate in-hand. Recent friction-tuning surface designs using soft pneumatic chambers show good control over grip friction; however, most require complex fabrication processes and/or custom gripper hardware. We present a practical structured fingerpad design for friction tuning that uses less than $1 USD of materials, takes only seconds to repair, and is easily adapted to existing grippers. Our design uses surface morphology changes to tune friction. The fingerpad is actuated by pressurizing its internal chambers, thereby deflecting its flexible grip surface out from or into these chambers. We characterize the friction-tuning capabilities of our design by measuring the shear force required to pull an object from a gripper equipped with two independently actuated fingerpads. Our results show that varying actuation pressure and timing changes the magnitude of friction forces on a gripped object by up to a factor of 2.8. We demonstrate additional features including macro-scale interlocking behaviour and pressure-based object detection.
A stimuli-responsive supramolecular polymer network has been constructed based on the host-guest interactions between the copolymer poly-P[5]A with pendent pillararene units and bis(sulfonium)diction guest *** formati...
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A stimuli-responsive supramolecular polymer network has been constructed based on the host-guest interactions between the copolymer poly-P[5]A with pendent pillararene units and bis(sulfonium)diction guest *** formation mechanism of the supramolecular polymer network has been explored by the intensive *** the addition of the competitive molecules and heating,the supramolecular polymer network could be dissociated and lead to clear changes in NMR spectroscopy and viscosity property.
Ferroelectric domain engineering with infrared femtosecond laser pulses has been a powerful technique to achieve a spatially modulated second-order nonlinear coefficient in three ***,studies regarding the in-fluence o...
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Ferroelectric domain engineering with infrared femtosecond laser pulses has been a powerful technique to achieve a spatially modulated second-order nonlinear coefficient in three ***,studies regarding the in-fluence of laser writing conditions on the light-induced ferroelectric domain inversion remain ***,an experimental study to reveal the role of laser polarization in light-induced domain inversions is *** dependence of the optical threshold and maximal writing depth of inverted domains on light polarization is ex-perimentally *** results are explained by considering the second-order nonlinear optical properties and birefringence-induced focus splitting in the *** findings are useful in fabricating high-quality and large-scale ferroelectric domain structures for applications in optics,electronics,and quantum technologies.
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