Preparation of Nickel-Copper Bilayers Coated on Single-Walled Carbon Nanotubes

Due to oxidizability of copper coating on carbon nanotubes, the interfacial bond strength between copper coating and its matrix is weak, which leads to the reduction of the macroscopic properties of copper matrix composite. The electroless coating technics was applied to prepare nickel-copper bilayers coated on single-walled carbon nanotubes. The coated single-walled carbon nanotubes were characterized through transmission electron microscope spectroscopy, field-emission electron microscope spectroscopy, X-ray diffractometry, and thermogravimetric analysis. The results demonstrated that the nickel-copper bilayers coated on single-walled carbon nanotubes possessed higher purity of unoxidized copper fine-grains than copper monolayers

Knowledge Domain and Emerging Trends in Organic Photovoltaic Technology: A Scientometric Review Based on CiteSpace Analysis

To study the rapid growth of research on organic photovoltaic (OPV) technology, development trends in the relevant research are analyzed based on CiteSpace software of text mining and visualization in scientific literature. By this analytical method, the outputs and cooperation of authors, the hot research topics, the vital references and the development trend of OPV are identified and visualized. Different from the traditional review articles by the experts on OPV, this work provides a new method of visualizing information about the development of the OPV technology research over the past decade quantitatively

Performance analysis of a strut-aided hypersonic scramjet by full-scale IDDES modeling

The uninstalled performance of a full-scale scramjet operating over Mach 7 to 10 and altitudes of 28 to 40 km was numerically analyzed by using high-fidelity Improved Delayed Detached Eddy Simulation (IDDES) with 125.10 million cells and Dynamic Zone Flamelet model (DZFM) with 21,294 flamelet zones. The inviscid thrust can be well correlated with dynamic pressure in the form of a gaussian function, whereas the viscous drag increases almost linearly with dynamic pressure. For the examined scramjet, net thrust is achieved for the low dynamic pressure range below 37 kPa and the high range above 55 kPa. The rule of mixed is burnt is observed, and the final combustion efficiencies vary from 66% to 82%. The upstream propagation of combustion occurs for most of the cases in the current strut-based combustor, and unstart occurs for the case of Mach 7 at 30 km. (C) 2021 Elsevier Masson SAS. All rights reserved

Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nanotubes

To achieve the reinforcement of copper matrix composite by single-walled carbon nanotubes, a three-step-refluxing purification of carbon nanotubes sample with HNO3-NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H2O2/HCl mixture was also repeated. Then, the purified carbon nanotubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nanotubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nanotubes. The thermal stability of the sample purified by H2O2/HCl treatment was slightly higher than that purified by HNO3-NaOH-HCl treatment. Nevertheless, the purification by HNO3-NaOH-HCl treatment was more effective for carboxyl functionalization on nanotubes than that by H2O2/HCl treatment. The Cu-coating on carbon nanotubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nanotubes purified by H2O2/HCl was oxidized more seriously than those on carbon nanotubes purified by HNO3-NaOH-HCl treatment

High-temperature transient-induced thermomechanical damage of fiber-reinforced ceramic-matrix composites in supersonic wind tunnel

This article is based on the supersonic directly connected wind tunnel. Through a specially designed experimental chamber, combined with infrared temperature measurement, high-speed camera, etc., in -situ monitoring of composite materials under airflow at Ma 3.0 with a total temperature of 950 similar to 1473K was carried out. The dimensional analysis method was used to propose dimensionless parameters to characterize the thermal coupling caused by high-speed airflow thermal shock. Research has shown that the thermal coupling effect of supersonic airflow causes uneven temperature inside the material, and the thermal stress caused by temperature gradient changes (including increasing and decreasing processes) is the main reason for material damage. The damage of ceramic matrix composites under thermal shock mainly manifests as a decrease in surface roughness, surface fiber fracture and a decrease in elastic modulus. In addition, the study also found that there are damage thresholds for the thermal shock effect of airflow at different total temperatures, which helps to further understand the thermomechanical damage mechanism and degradation law of composite structure under high -temperature transient conditions

Tanshinone IIA Improves Acute Gouty Arthritis in Rats through Regulating Neutrophil Activation and the NLRP3 Inflammasome

Objectives. To investigate the prevention and treatment effect of tanshinone IIA (TIIA) on acute gouty arthritis (AGA) and its mechanism. Methods. The anti-AGA effect of TIIA was observed in vivo and in vitro. Neutrophils were isolated from the abdominal cavity of mice, and the anti-AGA effect of TIIA was investigated in a rat model of MSU-induced AGA. The pathological changes of the ankle joint tissues were assessed by H&E. Cytokine and chemokine expression were determined by ELISA and RT-qPCR. The NLRP3 inflammasome pathway protein levels in the ankle joint tissues were evaluated via western blotting. Neutrophil migration was evaluated in air pouch and transwell assays. Immunohistochemistry and immunofluorescence analysis evaluate the release of myeloperoxidase (MPO), neutrophil elastase (NE), and citrullination of histone H3 (CitH3). Beclin-1 and LC3B expressions were determined using western blotting and immunofluorescence. Key Findings. Treatment with TIIA alleviated synovial hyperplasia and neutrophil infiltration, regulated cytokine and chemokine expressions, and inhibited NLRP3 activation in AGA rats, neutrophil migration, MPO, NE, and CitH3 expression, and LC3B and Beclin-1 protein expression. Conclusions. These results demonstrate that TIIA can effectively enhance AGA by focusing on the neutrophils and NLRP3 inflammasome, demonstrating that TIIA may act as a potential helpful agent for AGA

Novel inorganic electron transport layers for planar perovskite solar cells: Progress and prospective

Perovskite solar cells (PSCs) have emerged as a promising class of photovoltaic devices since they combine the benefits of high efficiency beyond 20%, low material cost, as well as easy and scalable processing. The appropriate choice of the electron transport layer (ETL) in these devices is one crucial aspect for achieving high efficient PSCs. The conventional ETL TiO2 is not the best choice due to its relatively low conductivity and problematic photocatalytic activity. Therefore, novel ETLs have attained increasing attention and are making rapid progress and with it the further development and optimization of planar PSCs has been promoted. In this review, we start by introducing the essential functions of ETLs in planar PSCs. Next, we give an extensive description of novel ETL materials, looking at both crystalline and amorphous systems. Their emergence, development, and accompanying optimization strategies will be discussed. Additionally, we provide a brief discussion about the correlation between materials, fabrication methods, and interface related issues. In the end, we propose some prospective research subjects that will be relevant for the further development of novel ETLs

Overexpression of OsbHLH107, a member of the basic helix-loop-helix transcription factor family, enhances grain size in rice (Oryza sativa L.)

Abstract Background Grain size, which is determined by grain length, grain width, and grain thickness, is an important determinant for grain yield in rice. Identification and characterization of new genes that are associated with grain size will be helpful for the improvement of grain yield in rice. Results We characterized the grain size mutant, larger grain size 1 (lgs1), derived from rice activation-tagged T-DNA insertion lines. Histological analysis showed that increased cell numbers in the longitudinal direction of spikelet hulls was responsible for the grain mutant phenotype in lgs1. Quantitative real-time PCR (qRT-PCR) analysis further showed that the expression levels of genes associated with the cell cycle in the young panicles of the lgs1 were higher than those in the wild type (WT), which might result in the increased cell numbers in lgs1 spikelet hulls. Insertion site analysis together with transgenic experiments confirmed that the lgs1 phenotype was caused by enhanced expression of truncated OsbHLH107, corresponding to the nucleotide (nt) 331–846 region (i.e., the transcriptional activation region of OsbHLH107) of the OsbHLH107 coding sequence (CDS). OsbHLH107 is a nucleus-localized bHLH transcription factor, which can form a homodimer with itself. Phylogenetic analysis showed that OsbHLH107 belonged to the same subfamily as OsPILs. OsPIL13 (OsPIL1) and OsPIL16 (APG) were reported to regulate grain size in rice. By transgenic experiments, we found that OsPIL11 could also regulate grain size. Conclusion We concluded that OsbHLH107 and its homologs are important regulators of grain size development and might be useful for grain yield improvement in rice