The microstructural evolution and grain growth kinetics of the hot rolled Ti–20Zr–6.5Al–4V (wt.%, TZ20) alloy during subsequent isothermal annealing were investigated. The XRD results show that the ...examined alloy is composed of α and β phases after annealing at temperatures from 750 °C to 850°C. The SEM results show that the microstructure of all annealed specimens is typical basketweave structure with interlaced α plates embedded in β matrix. Thickness growth kinetics of α plate in TZ20 alloy was investigated by designing various heat treatments. The grain growth exponent n, pre-exponential factor K0 and activation energy of boundary migration E of TZ20 alloy during isothermal annealing were determined. Finally, the relationship between thickness increment Δh, annealing temperature T and holding time t of isothermal annealed TZ20 alloy has been deduced. Mechanical properties of the examined alloy with various annealing treatments were also investigated. Tensile results show that the strength changes in the range of 1120MPa to 1246MPa, and the ductility in term of elongation varies from 9.1% to 14.3%. The relation between mechanical properties and microstructure was also discussed. This work is of great significance to guide the manufacture and to promote practical applications of TiZr-based alloys.
•Microstructure of the TZ20 alloy after various treatments was investigated.•Grain growth kinetics of the TZ20 alloy during isothermal annealing was analyzed.•The grain growth exponent n and activation energy E were obtained.•Relation between microstructure and annealing parameters was deduced.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
By atomic-scale high-angle annular dark field scanning transmission electron microscopy, we characterized a long period stacking ordered (LPSO) phase, 654R, in an Mg88Co5Y7 (at.%) as-cast alloy, ...which is an ordered intergrowth of 15R and 12H LPSO phases. The unique stacking sequence of 654R LPSO phase can be described as (T2)10(T3T¯3)143, with lattice parameters of a = 0.321 nm, c = 170.4 nm, and a space group of R3¯m. T/T¯ refers to AB′C/AC′B building blocks, while normal and subscript number respectively represent the number of Mg layers sandwiched between T/T¯ and the number of sub unit cells. The formation mechanism of 654R LPSO phase is also proposed.
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•654R long period stacking ordered (LPSO) phase was characterized at atomic level.•654R LPSO phase is an ordered intergrowth of 15R and 12H LPSO phase.•A new notation was introduced to describe stacking sequence of 654R LPSO phase.•The possible formation process of 654R LPSO structures was proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Using a total of 11.0 fb^{-1} of e^{+}e^{-} collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross ...sections and effective form factors for the process e^{+}e^{-}→Ξ^{-}Ξover ¯^{+} by means of a single baryon-tag method. After performing a fit to the dressed cross section of e^{+}e^{-}→Ξ^{-}Ξover ¯^{+}, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ^{-}Ξover ¯^{+} final states, and upper limits at the 90% confidence level on Γ_{ee}B for the processes ψ(4230)/ψ(4260)→Ξ^{-}Ξover ¯^{+} are determined. In addition, an excited Ξ baryon at 1820 MeV/c^{2} is observed with a statistical significance of 6.2-6.5σ by including the systematic uncertainty, and the mass and width are measured to be M=(1825.5±4.7±4.7) MeV/c^{2} and Γ=(17.0±15.0±7.9) MeV, which confirms the existence of the J^{P}=3/2^{-} state Ξ(1820).
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
To investigate the clinical value of serum glypican-3 (GPC3) detection in predicting recurrence of primary hepatocellular carcinoma (HCC).
Through univariate and multivariate logistic regression ...analysis, the patients pathologically diagnosed with HCC in our hospital from March 2019 to January 2021 were enrolled as the experimental group (
=113), and patients with follow-up time longer than 6 months were included in the prognosis group(
=64). At the same time,20 healthy individuals and 20 individuals with benign liver disease from the physical examination center were enrolled by simple random sampling as control group (
=40). The serum GPC3 and alpha-fetoprotein (AFP) levels were respectively detected by ELISA and chemiluminescence. Then, the study explored the influential factors of the recurrence in HCC patients and constructed the HCC-GPC3 recurrence predicting model by logistic regression.
In the research, the sensitivity of GPC3 for the diagnosis of HCC was 61.95% (70/113) and AFP was 52.21% (59/113), me
Pheromonicin-SA (Ph-SA) is a newly developed, engineered multidomain peptide that has a bactericidal effect against Staphylococcus aureus. The objective of this study was to characterize innate ...immune responses by Staph. aureus-stimulated bovine mammary epithelial cells (BMEC) following treatment with Ph-SA. Primary BMEC from one lactating Holstein cow were isolated and exposed to Staph. aureus for 2h, and then treated with rifampicin or Ph-SA. Total RNA was isolated from BMEC at 0, 2, 6, 12, and 24h postinfection, and the mRNA expression of selected genes, including toll-like receptor (TLR)2 and TLR4, IL-1β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and lactoferrin, was quantified by real-time PCR. In the rifampicin group, increases in the expression of mRNA for TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6h postinfection and in the expression of mRNA for TLR2 but not for TLR4 at 12h postinfection. In the Ph-SA group, increases in the mRNA expression of TLR2, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6h postinfection, and an increase in TLR4 mRNA expression was observed at 24h postinfection. At 24h postinfection, the mRNA expression of TLR4, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin was higher in the Ph-SA group than in the rifampicin group. In conclusion, Ph-SA might promote the expression of mRNA for TLR2, TLR4, the pro-inflammatory cytokines IL-1, IL-6, and TNF-α, the chemotactic factor IL-8, and lactoferrin in Staph. aureus-infected BMEC. Moreover, Ph-SA may be of value as an antibiotic in promoting innate immune responses by Staph. aureus-infected bovine mammary epithelial cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
One-dimensional nanostructures of SnO2 with a ribbonlike morphology have been prepared in large scale via rapid oxidation of elemental tin at 1080 °C. The products were characterized with scanning ...electron microscopy, X-ray powder diffraction, transmission electron microscopy, Raman scattering, and photoluminescence spectroscopy. The as-synthesized SnO2 nanoribbons appeared to be single crystals and had preferred 110 and 203 growth directions. The lengths of the nanoribbons were up to several hundreds of micrometers, and the typical width and thickness were in the range of 30−150 nm and 10−30 nm, respectively. The strong photoluminescence of the nanoribbons in the visible region suggested possible applications in nanoscaled optoelectronic devices. A possible growth mechanism for the SnO2 nanoribbons was proposed.
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IJS, KILJ, NUK, PNG, UL, UM
The dissolution of MnS inclusions could induce pitting corrosion in stainless steels, but its dissolution mechanism is poorly understood at the atomic scale. With the help of
ab initio
molecular ...dynamics calculations, one inevitable step in the dissolution of MnS is studied by simulating the process of one Mn ion leaving the surface. The reaction mechanism is determined to contain three steps with two large barriers and a small one, leading to two slow steps in the Mn ion dissolution. Comparing to the Na ion dissolution from NaCl, the barriers of the Mn ion dissolution are much larger, which is a reflection of their different electronic structures.
Energy curves of Mn ion dissolution.
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