The mechanical properties of epoxy resin can be enhanced by adding nanofillers into its matrix. This study researches and compares the impacts of adding nanofillers with different dimensions, ...including two-dimensional boron nitride and zero-dimensional silica, on the mechanical and toughness properties of epoxy resin. At low fractions (0–2.0 wt%), 2DBN/epoxy composites have a higher Young’s modulus, fracture toughness and critical strain energy release rate compared to SiO2/epoxy composites. However, the workability deteriorated drastically for BN/epoxy composites above a specific nanofiller concentration (2.0–3.0 wt%). BN prevents crack growth by drawing and bridging. SiO2 enhances performance by deflecting the crack direction and forming voids. Additionally, the dimension and content of nanofiller also influence glass transition temperature and storage modulus significantly.
The in-plane effective 90° magnetization rotation of Co2FeAl thin film grown on PMN-PT substrate induced by the electric field is investigated at room temperature.The magnetic hysteresis loops under ...different positive and negative electric fields are obtained,which reveals remanent magnetization can be mediated by the electric field.Moreover,under positive electric fields,the obvious 90° magnetization rotation can be observed,while remanent magnetization is nearly un-changed under negative electric fields.The result is consistent with the electric field dependence of effective magnetic field,which can be attributed to the piezostrain effect in Co2FeAl/PMN-PT structure.In addition,the piezostrain-mediated 90°magnetization rotation can be demonstrated by the result of resonance field changing with electric field in the measurement of ferromagnetic resonance,which is promising for the design of future multiferroic devices.
Dark solitons are widely applied in optical fiber communication system due to the characteristics of strong anti-interference and slow attenuation. The coupled nonlinear Schrödinger equations with ...the higher-order effects of third-order dispersion, self-steepening and self-frequency shift, which is modeled the propagation of ultrashort optical pulse through a multimode fiber or birefringence fiber, have been investigated analytically. By using the Hirota method, exact dark solitons, anti-dark solitons and dark double-hump solitons are constructed. The transmission characteristics of those solitons are analyzed, and the conditions for the transformation of states between them are discussed. Those presented results provide a new idea for the transformation of dark soliton states.
The effects of water vapor on the activity of the copper based catalysts with different supports such as CuO/γ-Al
2O
3, CuO/SiO
2 and CuO/TiO
2 for styrene combustion were investigated. The catalytic ...activity of the catalysts was tested in the absence of and presence of water vapor and the catalysts were characterized. Temperature programmed desorption (TPD) experiments and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) measurements were conducted in order to estimate and explain the water effects. Results showed that the existence of water vapor had a significant negative effect on the catalytic activity of these copper based catalysts due to the competition adsorption of water molecule. DRIFTS studies showed that the catalyst CuO/γ-Al
2O
3 had the strongest adsorption of water, while the catalyst CuO/TiO
2 had the weakest adsorption of water. H
2O-TPD studies also indicated that the order of desorption activation energies of water vapor on the catalysts or the strength of interactions of water molecules with the surfaces of the catalysts was CuO/γ-Al
2O
3
>
CuO/SiO
2
>
CuO/TiO
2. As a consequence of that, the CuO/TiO
2 exhibited the better durability to water vapor, while CuO/γ-Al
2O
3 had the poorest durability to water vapor among these three catalysts.
Surface plasmons (SPs) are expected to have a wide range of applications in many fields, so they have recently attracted much attention. However, most of the previous studies achieved the ...manipulation of SPs through designing the structure of the individual meta-atom. When developing the next generation of integrated photonic devices and components, it is essential to seek out new methods of software control, which enable more diverse modulation and higher efficiency. Here, the tunable emission of SPs with metasurfaces is systematically studied. SPs are a source of on-chip plasmonic vortices (PVs). To verify the controllability of the directional excitation of SPs, we designed beam deflectors with different angles of surface waves (SWs). Furthermore, PVs with different topological charges were generated by arranging spatially varied microslits. The proposed control strategy provides a common platform for various promising applications, such as on-chip generation of the propagation control of SPs and PVs.
This paper finishes the classification of three-generator finite
p
-groups
G
such that Φ(
G
) ⩽
Z
(
G
). This paper is a part of classification of finite
p
-groups with a minimal non-abelian subgroup ...of index
p
, and partly solves a problem proposed by Berkovich (2008).
We investigate the causal relationship between foreign ownership and international trade performance by comparing foreign‐acquired firms with similar domestic‐acquired firms in China with regard to ...changes in their post‐acquisition international trade performance. Our findings indicate that foreign ownership significantly enhanced the probability of both exporting and importing, and strongly increased trade value. Foreign ownership took effect from the year of the acquisition and persisted for at least 2 years. It stimulated both processing trade and ordinary trade, and expanded products and trading partners. Post‐acquisition trade performance also exhibited heterogeneity based on the different pre‐acquisition and post‐acquisition ownership. As for the underlying mechanisms, we show that firms experienced significant output expansion, increased export dependence, and eased financial constraints after foreign acquisition.
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