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Polyisocyanate was used to chemically functionalize carboxylated cellulose nanofibers (CNF-C). Composites of CNF-C/ monomer casting nylon (MC nylon) and modified CNF-C/MC nylon were fabricated by anionic ring-opening polymerization. The mechanical characteristics of the MC nylon composites and the dispersion of the CNF-C in the MC nylon were studied. The tensile strength and impact strength of composites were first increased with CNF-C addition, but then decreased as further CNF-C was added. The composites had good mechanical properties when CNF-C was added to MC nylon at 1.0 wt%, and the tensile strength and impact strength were increased by 21.2% and 34.9%, respectively, compared to MC nylon. When modified CNF-C was added at 1.5 wt%, the tensile strength of composites was increased by 47.90%. The addition of CNF-C causes an increase in the melting point, crystallinity, and crystallization temperature, which was confirmed by differential scanning calorimetry (DSC). The modified CNF-C had better dispersibility in MC nylon which was confirmed by scanning electron microscopy (SEM). KEYWORDS carboxylated cellulose nanofibers, composites, MC nylon, 1 | INTRODUCTION Cellulose nanofibers are the most abundant polymer material in nature and are a renewable and environment-friendly material resource. Nanocellulose is less than 100 nm in diameter and [...]

The predeformation prior to artificial aging plays an important role in enhancing the properties of Al–Cu–Li based alloys. This study focused on investigating the impact of a large amount of prerolling (20%) on the orientation variation and distribution characteristics of T1 precipitates in a rolled Al–Cu–Li alloy. The results revealed that T1 phases precipitated in the same orientation were not strictly parallel within a grain, a small angle existed between different phases in the same direction due to the orientation fluctuation of the matrix induced by prerolling. The misorientation degree of the T1 precipitates presented a slight expend tendency with increasing the aging time. Furthermore, the connection between this orientation distortion of the T1 phases and the tensile properties was discussed. Additionally, it was found that the T1 variants along different orientations were heterogeneously distributed, possibly due to the activation of different slip systems during the prerolling process and the variation in the number of nucleation sites among the nonparallel habit planes. [ABSTRACT FROM AUTHOR]

A novel plasmonic waveguide structure consisting of a rectangular resonator side coupled with a split ring resonator (SRR) and a metal–insulator–metal (MIM) waveguide with metal baffle was proposed. The transmission characteristics of the present structure were simulated by a finite-difference time-domain (FDTD) method. The results show that the structure can realize three typical plasmonically-induced reflection (PIR) windows. Meantime, the PIR window can be tuned vertically and horizontally, respectively, and multiple PIR windows with different wavelength intervals can also be obtained by changing the split position. In addition, the sensitivity of the proposed structure can reach up to 1,075 nm/RIU. Furthermore, a rectangular resonator was added to the other side of the plasmonic waveguide structure for realizing the dual-channel PIR window. Another SRR was added to form a symmetrical structure, which further improved the sensitivity and transmittance. Undoubtedly, the proposed structure will have potential applications in sensor and optical switches. [ABSTRACT FROM AUTHOR]

The effects of heat treatment temperature on the microstructure and mechanical properties of Cu0.3Cr2Fe2Ni3Mn2Nbx high-entropy alloys (HEAs) were studied. Results indicate that in the as-cast state, an Nb0 alloy is composed of a single FCC phase, and a Laves phase gradually forms as Nb content increases. After heat treatment at 800 °C, BCC solid solution phases rich in Cr, Fe, and Mn form in all alloys. The BCC phases in the Nb0.2 and Nb0.4 alloys decompose after heat treatment at 900 and 1000 °C, respectively, and the microhardness of the as-cast Cu0.3Cr2Fe2Ni3Mn2Nbx HEAs increases from 127 to 203 HV with increasing Nb content. After heat treatment, the microhardness of the alloys considerably improves, and the Nb0.4 alloy has the highest microhardness after heat treatment at 800 °C (approximately 346 HV). After heat treatment at 900 and 1000 °C, the microhardness of the three alloys decreases. The yield strength of the as-cast Cu0.3Cr2Fe2Ni3Mn2Nbx HEAs increases with Nb content and shows a trend of first increasing and then decreasing with increasing heat treatment temperature. The strengthening mechanism of the heat-treated alloys is mainly attributed to the second-phase strengthening of the Laves phase and the solid solution strengthening of the BCC phase. [ABSTRACT FROM AUTHOR]

This study proposes four kinds of hybrid source–grid–storage systems consisting of photovoltaic and wind energy, and a power grid including different batteries and hydrogen storage systems for Sanjiao town. HOMER-PRO was applied for the optimal design and techno-economic analysis of each case, aiming to explore reproducible energy supply solutions for China's industrial clusters. The results show that the proposed system is a fully feasible and reliable solution for industry-based towns, like Sanjiao, in their pursuit of carbon neutrality. In addition, the source-side price sensitivity analysis found that the hydrogen storage solution was cost-competitive only when the capital costs on the storage and source sides were reduced by about 70%. However, the hydrogen storage system had the lowest carbon emissions, about 14% lower than the battery ones. It was also found that power generation cost reduction had a more prominent effect on the whole system's NPC and LCOE reduction. This suggests that policy support needs to continue to push for generation-side innovation and scaling up, while research on different energy storage types should be encouraged to serve the needs of different source–grid–load–storage systems. [ABSTRACT FROM AUTHOR]

In the external drainage water of Xinjiang Karamay Petrochemical Company, the calcium and magnesium ion contents are as high as 630 mg/L and 1170 mg/L, respectively. These ions are subsequently scaled at large quantities in water treatment equipment, which greatly reduces the efficiency of the process. This study used a coupled chemical precipitation (CP) and electrocoagulation (EC) method to deal with external drainage water. The results show that the removal rates of calcium and magnesium were 94.71% and 96.33%, respectively, when the pH was adjusted with sodium silicate and EC was introduced after saturating the water samples with CO2. In this study, a quadratic polynomial equation was developed for predicting the removal of calcium and magnesium ions using this coupled technique under three factors of current density (CD) (15, 20 and 25 mA/cm2), reaction time (RT) (30, 40 and 50 min) and pH (10.0, 10.5 and 11.0). It was found that these three variables have a significant effect on the removal of both the abovementioned ions. The response surface method based on a Box–Behnken design showed that the average removal rates of calcium and magnesium ions could be 96.57% and 98.66% at a CD of 22 mA/cm2, RT of 46 min and pH of 11. This study confirmed the presence of calcium carbonate in the solid product through XRD and SEM analysis. The results indicate that this study is promising, and the developed technique can also be used to remove the high concentrations of calcium and magnesium ions from different wastewaters. [ABSTRACT FROM AUTHOR]

III-nitride heterostructure-based metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs), compared with Schottky and p-GaN gate HEMTs, have demonstrated significant potential in the next-generation high-power electronic devices due to their exceptional gate reliability. This study presents a comprehensive investigation of threshold voltage (VTH) instability in III-nitride heterostructure-based MIS-HEMTs, with a specific emphasis on the interfaces of the multi-heterostructures. Two widely studied amorphous materials, namely, Al2O3 and SiNx, have been extensively examined as primary gate insulators in GaN-based MIS-HEMTs. To efficiently remove native oxides from the (Al)GaN surface, a novel in situ high-temperature remote plasma pretreatment (RPP) technique has been developed. This technique involves sequential application of NH3/N2 plasmas on the (Al)GaN surface before depositing the gate insulators using plasma-enhanced atomic layer deposition. The remarkable RPP process has proven to be a highly effective method for revealing atomic steps on the GaN surface, irrespective of whether the surface has undergone oxidation or etching processes. To further enhance the interface quality and potentially reduce bulk traps in the gate insulator, optimization of deposition temperature and post-deposition annealing conditions have been explored. Additionally, an electron-blocking layer, such as SiON, is incorporated into the MIS-HEMTs to prevent electron injection into bulk traps within the insulator. Novel characterization techniques including constant-capacitance and isothermal-mode deep-level transient spectroscopy have also been developed to explore the failure mechanisms in MIS-HEMTs. These techniques allow for the differentiation between bulk traps in the GaN epitaxy and those present within the gate insulators. This in-depth physical understanding provides valuable insights into the sources of failure in GaN-based MIS-HEMTs. [ABSTRACT FROM AUTHOR]