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51.
Mengwei Liu Jin Zhao Shunzo Shimai Dan Han Jian Zhang Shiwei Wang 《Journal of the American Ceramic Society》2022,105(7):4632-4638
MgAl2O4 transparent ceramics were shaped by a commonly used polyacrylic acid (PAA), which acted as both dispersant and gelling agent. The spinel slurries were prepared by ball-milling MgAl2O4 powder, PAA, and water in an attrition mill. The gelling of slurries happened at room temperature in air atmosphere without any other organic additive. The gelling mechanism was the formation of chelates between Mg2+ and carboxyl groups (-COO−) of PAA. The frequency-based testing method was applied to investigate the gelling process of the as-prepared slurry. In addition, a novel in situ characterization method based on a modified indentation testing was invented to better understand the strengthening of the wet green body with time and to guide when demolding could be carried out. After sintering, transparent MgAl2O4 ceramics with high in-line transmittance were resulted. 相似文献
53.
Dan Liu Hongying Yang Jianhui Li Jiaqi Li Yizhe Dong Chuntian Yang Yuting Jin Lekbach Yassir Zhong Li David Hernandez Dake Xu Fuhui Wang Jessica A.Smith 《材料科学技术学报》2021,79(20):101-108
Titanium alloys possess excellent corrosion resistance in marine environments,thus the possibility of their corrosion caused by marine microorganisms is neglected.In this work,microbiologically influenced corrosion (MIC) of TC4 titanium alloy caused by marine Pseudomonas aeruginosa was investigated through electrochemical and surface characterizations during a 14-day immersion test.Results revealed that the unstable surface caused by P.aeruginosa resulted in exposure of Ti2O3 and severe pitting corrosion with maximum pit depth of 5.7 μm after 14 days of incubation.Phenazine-1-carboxy[ate (PCN),secreted by P.aeruginosa,promoted extracellular electron transfer (EET) and accelerated corrosion.Deletion of the phzH gene,which codes for the enzyme that catalyzes PCN production,from the P.aeruginosa genome,resulted in significantly decreased rates of corrosion.These results demonstrate that TC4 titanium alloy is not immune to marine MIC,and EET contributes to the corrosion of TC4 titanium alloy caused by P.aeruginosa. 相似文献
54.
Zhong-Zheng Jin Min Zha Hai-Long Jia Pin-Kui Ma Si-Qing Wang Jia-Wei Liang Hui-Yuan Wang 《材料科学技术学报》2021,81(22):219-228
In this study,we successfully prepared a Mg-6Zn-0.2Ca alloy by utilizing sub-rapid solidification (SRS)combined with hard-plate rolling (HPR),whose elongation-to-failure increases from ~17 % to ~23 %without sacrificing tensile strength (~290 MPa) compared with its counterpart processed via conven-tional solidification (CS) followed by HPR.Notably,both samples feature a similar refined grain structure with an average grain size of ~2.1 and ~2.5 μm,respectively.However,the high cooling rate of ~ 150 K/s introduced by SRS modified both the size and morphology of Ca2Mg6Zn3 eutectic phase in comparison to those coarse ones under CS condition.By subsequent HPR,the Ca2Mg6Zn3 phase was further refined and dispersed uniformly by severe fragmentation.Specially,the achieved supersaturation containing exces-sive Ca solute atoms due to high cooling rate was maintained in the SRS-HPR condition.The mechanisms that govern the high ductility of the SRS-HPR sample could be ascribed to following reasons.First,refined Ca2Mg6Zn3 eutectic phase could effectively alleviate or avoid the crack initiation.Furthermore,excessive Ca solute atoms in α-Mg matrix result in the yield point phenomenon and enhanced strain-hardening ability during tension.The findings proposed a short-processed strategy towards superior performance of Mg-6Zn-0.2Ca alloy for industrial applications. 相似文献
55.
56.
Jin Wang Mengke Zhang Guanglong Yang Wenwu Song Weiting Zhong Xunyue Wang Minmin Wang Tongming Sun Yanfeng Tang 《Advanced functional materials》2021,31(33):2101532
Highly efficient electrocatalysts composed of earth-abundant elements are desired for water-splitting to produce clean and renewable chemical fuel. Herein, a heteroatomic-doped multi-phase Mo-doped nickel phosphide/nickel sulfide (Mo-NiPx/NiSy) nanowire electrocatalyst is designed by a successive phosphorization and sulfuration method for boosting overall water splitting (both oxygen and hydrogen evolution reactions (HER)) in alkaline solution. As expected, the Mo-NiPx/NiSy electrode possesses low overpotentials both at low and high current densities in HER, while the Mo-NiPx/NiSy heterostructure exhibits high active performance with ultra-low overpotentials of 137, 182, and 250 mV at the current density of 10, 100, and 400 mA cm−2 in 1 m KOH solution, respectively, in oxygen evolution reaction. In particular, the as-prepared Mo-NiPx/NiSy electrodes exhibit remarkable full water splitting performance at both low and high current densities of 10, 100, and 400 mA cm−2 with 1.42, 1.70, and 2.36 V, respectively, which is comparable to commercial electrolysis. 相似文献
57.
Muhammad Sheeraz Mamoon Ur Rashid Asad Ali Fazli Akram Ho Jeong Lee Jin San Choi Jong-Seong Bae Yong Soo Kim Young-Han Shin Chang Won Ahn Tae Heon Kim 《Journal of the European Ceramic Society》2021,41(10):5155-5162
We demonstrate the structural evolution of polymorphic phases in Al2O3-inserted SrMnO3 ceramics synthesized by solid state reaction. While the 4H-hexagonal phase is predominant in pure SrMnO3 ceramics, a small amount of 6H-hexagonal polymorph is identified in addition to the primary 4H-hexagonal SrMnO3 and the secondary hexagonal SrAl2O4 phases in the as-sintered ceramics, evidenced by x-ray diffraction and subsequent Rietveld refinement analyses. The existence of the 6H-hexagonal SrMnO3 phase is corroborated using Raman spectroscopy. The chemical compositions and electronic structures of the Al2O3-inserted SrMnO3 compounds are also examined using energy dispersive spectroscopy and x-ray photoelectron spectroscopy, respectively. The first-principles calculations reveal that there is no clear difference between the total energies of 4H- and 6H-hexagonal polymorphs regardless of the presence/absence of Sr and oxygen vacancies. Possible origins are discussed with the estimation of actual strain based on the refined lattice parameter of 6H SrMnO3. 相似文献
58.
Jin Kono Masakatsu Ueda Atsushi Sengiku Sylvia O. Suadicani Osamu Ogawa Hiromitsu Negoro 《International journal of molecular sciences》2021,22(4)
Connexin43 (Cx43), the main gap junction and hemichannel forming protein in the urinary bladder, participates in the regulation of bladder motor and sensory functions and has been reported as an important modulator of day–night variations in functional bladder capacity. However, because Cx43 is expressed throughout the bladder, the actual role played by the detrusor and the urothelial Cx43 is still unknown. For this purpose, we generated urothelium-specific Cx43 knockout (uCx43KO) mice using Cre-LoxP system. We evaluated the day–night micturition pattern and the urothelial Cx43 hemichannel function of the uCx43KO mice by measuring luminal ATP release after bladder distention. In wild-type (WT) mice, distention-induced ATP release was elevated, and functional bladder capacity was decreased in the animals’ active phase (nighttime) when Cx43 expression was also high compared to levels measured in the sleep phase (daytime). These day–night differences in urothelial ATP release and functional bladder capacity were attenuated in uCx43KO mice that, in the active phase, displayed lower ATP release and higher functional bladder capacity than WT mice. These findings indicate that urothelial Cx43 mediated ATP signaling and coordination of urothelial activity are essential for proper perception and regulation of responses to bladder distension in the animals’ awake, active phase. 相似文献
59.
Sudong Chae Seungbae Oh Kyung Hwan Choi Jin Woong Lee Jiho Jeon Zhixiang Liu Cong Wang Chaeheon Woo Liyi Shi Joohoon Kang Si Young Song Sung Jae Kim Jung Heon Lee Hak Ki Yu Jae-Young Choi 《Ceramics International》2021,47(9):11935-11941
To achieve the stable dispersion of 1D van der Waals crystal Mo6S3I6 in aqueous media, the tri-block copolymer (Poloxamer) is used as dispersant. The head group of Poloxamer, hydrophobic polypropylene oxide parts can be adsorbed to Mo6S3I6 surface by hydrophobic interaction and the tail group with hydrophilic polyethylene oxide exposed to the outside of the Mo6S3I6 is soluble in water and can form sufficient steric hindrance, resulting in stable aqueous dispersion in nm scale. The excellent biocompatibility of aqueous dispersed nm scale 1D Mo6S3I6 was demonstrated by effective proliferation of C2C12 cells. 相似文献
60.