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In this work, a novel approach involving coating fine PEEK powder on prepreg is introduced to improve wedge peel strength and reduce interlaminar voids. CF/PEEK laminates with resin interleaving are in situ consolidated by laser-assisted fiber placement. The morphology of the powdered surface is obtained using an optical profilometer, and the surface roughness and volume of added resin are calculated accordingly. Interface and surface temperature are measured during the layup process. Thermal history indicates that very short bonding time is the dominating factor for voids and limited interlayer strength. Laminate porosity and microscopic features are characterized with an optical microscope. The porosity of resin-interleaved laminates decreases to 3.7%, while the resin content only increases by 4.5% in the meantime. This is because interlayer resin particles rapidly melt under laser heating and quickly fill the voids between layers. The wedge peel strength of resin-interleaved laminates can increase by 30.1% without a repass treatment. This could be attributed to the increase in resin intimate contact and reduction in interlayer voids. [ABSTRACT FROM AUTHOR]

The objective of this study is to extract amino acids from fish processing discards for the preparation of highly effective and degradable corrosion inhibitors. The composition of fish processing discards extract (FPDE) was characterized by HPLC and FTIR. The results showed that the main components of FPDE are amino acids and contain a large number of unsaturated functional groups. Electrochemical techniques (electrochemical impedance spectroscopy (EIS) and Tafel), surface analysis (XPS and AFM), and molecular dynamics simulations (MDS) were conducted to investigate the corrosion inhibition mechanism of FPDE for carbon steel in 1 mol/L HCl. As shown by electrochemical tests, FPDE exhibits mixed-type corrosion inhibition with a maximum inhibition efficiency of 93.3%. FPDE exhibits excellent corrosion inhibition properties on carbon steel surfaces by forming a high coverage film through chemisorption and physisorption. Indeed, the advantages of remarkable inhibition efficiency and facile extraction methods allow FPDE to become a promising corrosion inhibitor for practical applications. [ABSTRACT FROM AUTHOR]

This study utilized Schizochytrium extract (SE) to explore its protective effect on carbon steel in a 0.5 mol/L H2SO4 solution. The main functional groups of SE were investigated by Fourier infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS). The following conclusions were drawn from electrochemical tests: A corrosion inhibition efficiency of 88.7% was achieved when 1000 mg/L SE was added to a 0.5 mol/L H2SO4 solution. The corrosion inhibition efficiency of SE increased with the increase in corrosion inhibitor concentration but decreased with the increase in temperature. From the polarization curves, the primary function of SE is to prevent metal dissolution at the anode. The morphology of the corroded steel surface was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques, and a smoother metal surface was observed when SE was added to the H2SO4 solution. Parameters such as dipole moments, Mullikan charges, equivalent surfaces (ESP) and binding energies of the four constituent molecules present in SE were calculated using quantum chemical calculations (QC) and molecular dynamics simulations (MS). It was found that the functional groups that play the role of adsorption are mainly carboxyl groups. In addition, Langmuir adsorption isotherms showed that the extracts could adhere to the metal surface and form a long-lasting protective film, thus effectively inhibiting corrosion. [ABSTRACT FROM AUTHOR]

In recent years, with the continuous development of the capital market and intelligent internet of things (IIoTs) technologies, investors have focused more on IIoTs enterprises' stocks. Since the stocks of IIoTs enterprises have the characteristics of heavy capital flows and high stock price volatility, the effective prediction of IIoTs stock price changes plays an extremely important role in improving investment returns and controlling investment risks. According to the above characteristics, our model takes stock trend fluctuations and time series indicator changes into consideration and comprehensively captures IIoTs stock information from both the temporal domain and the spatial domain. Specifically, the proposed model is a dual-view model that incorporates selected trading indicators to predict the closing prices of stocks. In the first view, an RNN model is designed to enlarge the receptive field of the model. In the second view, we introduce an attention mechanism to extract the influences of individual stock trends on the forecasting target. To verify the validity of this prediction method, we compare it with six other stock prediction methods. The results show that on the Ping An (601318) and IFLYTEK (002230) datasets, our method achieves the best results, that is, the lowest RMSE values. [ABSTRACT FROM AUTHOR]

Corrosion is the process of damaging materials, and corrosion of metallic materials frequently results in serious consequences. The addition of corrosion inhibitors is the most effective means of preventing metal corrosion. Until now, researchers have made unremitting efforts in the research of high-efficiency green corrosion inhibitors, and research on biomass corrosion inhibitors in a class of environmentally friendly corrosion inhibitors is currently quite promising. This work presents the classification of green biomass corrosion inhibitors in detail, including plant-based corrosion inhibitors, amino acid corrosion inhibitors, and biosurfactant corrosion inhibitors, based on the advantages of easy preparation, environmental friendliness, high corrosion inhibition efficiency, and a wide application range of biomass corrosion inhibitors. This work also introduces the preparation methods of biomass corrosion inhibitors, including hydrolysis, enzymatic digestion, the heating reflux method, and microwave extraction. In addition, the corrosion inhibition mechanisms of green biomass corrosion inhibitors, including physical adsorption, chemisorption, and film-forming adsorption, and evaluation methods of biomass corrosion inhibitors are also explicitly described. This study provides valuable insights into the development of green corrosion inhibitors. [ABSTRACT FROM AUTHOR]