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排序方式: 共有384条查询结果,搜索用时 78 毫秒
1.
Colin Robert Witiwat Best Thitasiri Dimitrios Mamalis Zakareya Elmo Hussein Muhammad Waqas Dipa Ray Norbert Radacsi Vasileios Koutsos 《应用聚合物科学杂志》2021,138(5):49749
The through-thickness conductivity of carbon fiber reinforced polymer (CFRP) composite was increased by incorporating multiwalled carbon nanotubes in the interlaminar region. Carbon nanotubes (CNTs) were dispersed in a polyethylenimine (PEI) binder, which was then coated onto the carbon fiber fabric. Standard vacuum-assisted resin infusion process was applied to fabricate the composite laminates. This modification technique aims to enhance the electrical conductivity in through-thickness direction for the purpose of nondestructive testing, damage detection, and electromagnetic interference shielding. CNT concentrations ranging from 0 to 0.75 wt% were used and compared to pristine CFRP samples (reference). The through-thickness conductivity of the CFRP exhibited an improvement of up to 781% by adopting this technique. However, the dispersion of CNT in PEI led to a viscosity increase and poor wetting properties which resulted in the formation of voids/defects, poor adhesion (as shown in scanning electron micrographs) and the deterioration of the mechanical properties as manifested by interlaminar shear strength and dynamic mechanical analysis measurements. 相似文献
2.
Yazhi Liu Shuofeng Liang Chenrui Yuan Andreas Best Michael Kappl Kaloian Koynov Hans-Jürgen Butt Si Wu 《Advanced functional materials》2021,31(37):2103908
Anticounterfeiting materials are used to distinguish real banknotes, products, and documents from counterfeits, fakes, or unauthorized replicas. However, conventional anticounterfeiting materials generally exhibit a single anticounterfeiting function, resulting in a low level of security. Herein, a novel anticounterfeiting nanocomposite is demonstrated with numerous prominent security features. The nanocomposite is fabricated by doping upconverting nanoparticles (UCNPs) in a photoresponsive azobenzene-containing polymer (azopolymer). Because of the cis–trans photoisomerization of the azopolymer, the nanocomposite exhibits photoinduced reversible color changes suitable for anticounterfeiting applications. Additionally, the hard nanocomposite can be converted to a rubber-like soft solid by light irradiation. Imprinted microstructures are fabricated on the photosoftened nanocomposite, which result in photonic colors. Moreover, polarization-dependent structures are fabricated on the nanocomposite via photoinduced orientation for encryption. Importantly, UCNPs in the nanocomposite emit visible light upon excitation by near-infrared light, enabling the observation of various anticounterfeiting structures with high contrast. An advantage of the anticounterfeiting nanocomposite is that the security features can be observed by the naked eye for quick discrimination and can be analyzed using laboratory equipment for higher accuracy. The anticounterfeiting nanocomposite is easily processed on paper, glass, and plastic, which demonstrates its potential anticounterfeiting functions for banknotes, wines, and medicines. 相似文献
3.
Two‐Step Protein Labeling by Using Lipoic Acid Ligase with Norbornene Substrates and Subsequent Inverse‐Electron Demand Diels–Alder Reaction 下载免费PDF全文
Marcel Best Anna Degen Mathis Baalmann Tobias T. Schmidt Dr. Richard Wombacher 《Chembiochem : a European journal of chemical biology》2015,16(8):1158-1162
Inverse‐electron‐demand Diels–Alder cycloaddition (DAinv) between strained alkenes and tetrazines is a highly bio‐orthogonal reaction that has been applied in the specific labeling of biomolecules. In this work we present a two‐step labeling protocol for the site‐specific labeling of proteins based on attachment of a highly stable norbornene derivative to a specific peptide sequence by using a mutant of the enzyme lipoic acid ligase A (LplAW37V), followed by the covalent attachment of tetrazine‐modified fluorophores to the norbornene moiety through the bio‐orthogonal DAinv . We investigated 15 different norbornene derivatives for their selective enzymatic attachment to a 13‐residue lipoic acid acceptor peptide (LAP) by using a standardized HPLC protocol. Finally, we used this two‐step labeling strategy to label proteins in cell lysates in a site‐specific manner and performed cell‐surface labeling on living cells. 相似文献
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Alaster Yoxall Victor Gonzalez Joshua Best Elena M. Rodriguez‐Falcon Jennifer Rowson 《Packaging Technology and Science》2019,32(10):496-507
Accessible packaging is continually receiving greater attention as an ageing population becomes a primary driver behind inclusive design. As we age, our strength dexterity and some cognitive functions decline. For this reason, the ease of interaction with simple tasks in daily living becomes an ever increasing concern. ISO 17480 “Packaging Guidelines” consider capability issues relating to packaging and ageing to broadly come under three areas, namely, strength, dexterity, and cognition. Significant previous work has been undertaken looking at the issue of strength on packaging accessibility, with fewer studies looking at the relationship between the physical demands of dexterity and the understanding of how to open the pack. In this previous work, there has been little attempt to quantify the effect of the affordances, perceptual information and symbology, and the physical demands of the pack and how this relates to accessibility. Hence, this exploratory study seeks to use motion capture and a dexterity test, along with a cognitive demand test to study this relationship and any changes with age. This research indicates that the dexterous demands of a task are linked to the cognitive demands; and thus in reaching a level of comprehension of the pack and how to access the product a subject may interact with a pack effectively. 相似文献
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Reece N. Oosterbeek Kalliope I. Margaronis Xiang C. Zhang Serena M. Best Ruth E. Cameron 《Journal of the European Ceramic Society》2021,41(1):901-911
Phosphate glasses for bioresorbable implants display dissolution rates that vary significantly with composition, however currently their mechanisms of dissolution are not well understood. Based on this systematic study we present new insights into these mechanisms. Two-stage dissolution was observed, with time dependence initially parabolic and later linear, and a two-stage model was developed to describe this behaviour. Dissolution was accelerated by lower Ca concentration in the glass, and lower pH in the dissolution medium. A new dissolution mechanism is proposed, involving an initial stage where diffusion-controlled formation of a conversion layer occurs. Once the conversion layer is stabilised, layer dissolution reactions become rate-limiting. Under this mechanism the transition time is sensitive to the nature of the conversion layer and solution conditions. These results reveal the dependence of P2O5–CaO–Na2O glass dissolution on solution pH, and provide new insight into the dissolution mechanisms, particularly regarding the transition between the two dissolution stages. 相似文献
9.
Michael J. Best Robert R. Grauer Jaroslava Hlouskova Xili Zhang 《Computational Economics》2014,44(1):45-65
Prospect theory postulates that the utility function is characterized by a kink (a point of non-differentiability) that distinguishes gains from losses. In this paper we present an algorithm that efficiently solves the linear version of the kinked-utility problem. First, we transform the non-differentiable kinked linear-utility problem into a higher dimensional, differentiable, linear program. Second, we introduce an efficient algorithm that solves the higher dimensional linear program in a smaller dimensional space. Third, we employ a numerical example to show that solving the problem with our algorithm is 15 times faster than solving the higher dimensional linear program using the interior point method of Mosek. Finally, we provide a direct link between the piece-wise linear programming problem and conditional value-at-risk, a downside risk measure. 相似文献
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