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Ta-10W alloy has great potential in the aerospace and nuclear industries due to its good formability, high melting point and excellent high-temperature strength. The purpose of this study was to experimentally research the tribological behaviors of Ta-10W at elevated temperatures and the effects of temperatures on the friction coefficient and the wear rate of Ta-10W in sliding wear. It was found that the main wear mechanism of the material at 100°C was abrasive wear, as well as adhesive wear and slight oxidative wear occurred at 200°C and 300°C. The friction coefficients increased as the temperature rose, which was attributed to the increase in metal viscosity at elevated temperatures. The wear rate gradually decreased with the temperature rising, such that there was a conversion from severe wear to light wear. At 200°C and 300°C, a large amount of stable oxide film covered the scar surface, resulting in decreased wear rate.

In order to maximize the reuse of used electronic component resources, while reducing environmental pollution, Cu metal was recycled from wasted CPU sockets by the reformative slurry electrolysis method. However, the influences on the regulation of the Cu recovery rate and purity from waste CPU slots, by slurry electrolysis, has not been systematically elucidated in previous studies. In this work, the effects of H2SO4 concentration, slurry density, NH4Cl concentration, current density, and reaction time, on the recovery rate and purity of Cu in slurry electrolysis, were researched by systematic experimental methods. The results showed that the recycled metal elements were mainly present as powders from the cathode, rather than in the electrolyte. Moreover, the metallic elements in the cathode powder consisted of mostly Cu and small amounts of Sn and Ni. The recovery rate and purity of Cu were up to 96.19% and 93.72%, respectively, with the optimum conditions being: an H2SO4 concentration of 2 mol/L, slurry density of 30 g/L, NH4Cl concentration of 90 g/L, current density of 80 mA/cm2, and reaction time of 7 h. Compared with previous studies, the Cu recovered in this experiment was present in the cathode powder, which was more convenient for the subsequent processing. Meanwhile, the recovery rate of Cu was effectively improved. This is an important guideline for the subsequent application of slurry electrolysis for Cu recovery.

In this study, we demonstrate the effects of surfactants on the morphology of Nb2C MXene-derived ferroelectric KNbO3 crystals. We synthesized plate-like KNbO3 crystals using Nb2C MXene and KOH as niobium and potassium sources, respectively, and sodium dodecyl sulfate as the surfactant. In addition, we conducted the same hydrothermal process for Nb2C MXene and KOH as niobium and potassium sources, respectively, and benzyltriethylammonium chloride as a surfactant; we found that the final product exhibits bulk morphology. We show that the morphology of MXene-derived KNbO3 crystals is strongly related to the interaction between the MXene flakes and the functional groups of the surfactant during the hydrothermal process.

Acute myeloid leukemia (AML) is a fatal disease characterized by the accumulation of immature myeloid blasts in the bone marrow (BM). Cytokine provide signals for leukemia cells to improve their survival in the BM microenvironment. Previously, we identified interleukin-33 (IL-33) as a promoter of cell survival in a human AML cell line and primary mouse leukemia cells. In this study, we report that the cell surface expression of IL-33–specific receptor, Interleukin 1 Receptor Like 1 (IL1RL1), is elevated in BM cells from AML patients at diagnosis, and the serum level of IL-33 in AML patients is higher than that of healthy donor controls. Moreover, IL-33 levels are found to be positively associated with IL-6 levels in pediatric patients with AML. In vitro, IL-33 treatment increased IL-6 mRNA expression and protein level in BM and peripheral blood (PB) cells from AML patients. Evidence was also provided that IL-33 inhibits cell apoptosis by activating p38 mitogen-activated protein kinase (MAPK) pathway using human AML cell line and AML patient samples. Finally, we confirmed that IL-33 activated IL-6 expression in a manner that required p38 MAPK pathway using clinical AML samples. Taken together, we identified a potential mechanism of IL-33–mediated survival involving p38 MAPK in pediatric AML patients that would facilitate future drug development.

During the reentry process, the plasma sheath covering the surface of the hypersonic aircraft will cause the amplitude attenuation and phase jitter of the communication electromagnetic waves. Channel parameters such as the electron density and collision frequency of the plasma sheath reflect the changing trend of the plasma sheath, and these parameters can be measured by physical means. However, these parameters cannot directly reflect the change of the channel communication ability and cannot directly serve the design of communication methods in the plasma sheath. Due to the particularity of the plasma sheath, the traditional channel estimation method for Additive White Gaussian Noise channels will no longer be applicable. This paper presents a channel capacity estimation method for dynamic plasma sheath. First, the plasma sheath is equivalent to a discrete input continuous output memoryless channel, and then the channel capacity expression is derived according to Shannon formula. Finally, the channel capacity of the dynamic plasma sheath is estimated by calculating the transition probability density function. The simulation results show that the channel capacity of the dynamic plasma sheath is affected by both the signal-to-noise ratio (SNR) and the dynamic parameters of the plasma sheath. When the electron density is small, the channel capacity is mainly affected by the SNR. As the electron density increases, the dynamic parameters of the plasma sheath gradually become the main factor affecting the channel capacity. This method is a theoretical analysis of the channel capacity when the channel parameters of the plasma channel are known, and it is meaningful for conducting the work of communication methods design.

Compact spherical WC-12Co composite powder was deposited on 304 stainless steel substrate by multi-layer laser powder deposition (LPD) to fabricate cemented carbide coating. The phase constitution and microstructure of the coating as well as the feedstock powder were characterized. Microhardness and dry sliding wear tests were also performed to assess the mechanical properties of the coating. The results showed that the coating exhibited distinct microstructures and phase constitutions at different depths due to the various thermal cycles and the resulting heat damages of feedstock powders. The upper region of the coating (i.e. the wear resistant layer) exhibited bimodal microstructure in which the incompletely dissolved WC-Co composite particles preserved the original submicron sintered structure and secondary carbides were precipitated around them. Owing to the fine-grained strengthening of submicron WC grains in the undissolved areas, the microhardness of wear resistant layer was enhanced to 8 times that of the substrate. The wear rate of the cemented carbide coating was about three orders of magnitude lower than that of the substrate when dry sliding against Al _2 O _3 ball under 10 N normal load. The bimodal structure of the wear resistant layer and the synergistic enhancement of differently sized carbides are the key factors for the excellent wear resistance of the coating.

A novel nano-WC/Cu-based composite with nanometer WC dispersed in the copper matrix was successfully prepared by vacuum hot-pressing sintering. The effects of different hot-pressing sintering temperatures on the microstructure, conductivity, strength, and hardness of the composite were investigated. As a result, with the increase of temperature, the distribution of nano-WC particles in the matrix is more even, and the relative density can reach about 100% when sintering temperature increase to 1075 °C. The electrical conductivity of the composites sharply increases from 62.5 to 90%IACS when sintering temperature increase from 950 °C to 1100 °C. Furthermore, as the sintering temperature rises from 950 °C to 1100 °C, the ultimate tensile strength gradually increases from 123 to 425 Mpa, and the hardness increases from 127.5 to 150 HV. In addition, the composite also displayed excellent resistance to high temperature softening at 800 °C.