18 research outputs found
Development and commissioning of FBG sensors for impact test of rock fall protective barrier
A high-sensitivity fiber Bragg grating displacement sensor based on transverse property of a tensioned optical fiber configuration and its dynamic performance improvement
GPa grade cryogenic strength yet ductile high-entropy alloys prepared by powder metallurgy
The carbon-doped Fe50Mn30Co10Cr10 HEAs with excellent cryogenic mechanical properties were prepared by powder metallurgy, and their tensile deformation behavior and strain-hardening mechanism were investigated. The yield strength of the HEAs at 77Â K improved from 489.7 to 1087.0Â MPa as the carbon content increased from 0 to 3Â at. %, which mainly stems from the increased lattice friction caused by the addition of carbon and the cryogenic environment; the ultimate tensile strength of the HEAs doped with 2 and 3Â at. % carbon reached 1.2 and 1.4Â GPa, respectively, while the elongation to fracture reached 31.6Â % and 16.8Â %, respectively, which is mainly attributed to the joint activation of microbands, twinning, and HCP phase. The deformation mechanism gradually changed from deformation-induced phase transformation to microbands and twinning with increasing carbon content under cryogenic conditions. This study provides a meaningful reference for the design and development of powder metallurgy HEAs with excellent performance in cryogenic applications
Chemical stability of yellow pigment extracted from the flower bud of Sophora japonica L. (Huaimi)
Amorphizing noble metal chalcogenide catalysts at the single-layer limit towards hydrogen production
Rational design of noble metal catalysts with the potential to leverage efficiency is vital for industrial applications. Such an ultimate atom-utilization efficiency can be achieved when all noble metal atoms exclusively contribute to catalysis. Here, we demonstrate the fabrication of a wafer-size amorphous PtSex film on a SiO2 substate via a low-temperature amorphization strategy, which offers single-atom-layer Pt catalysts with high atom-utilization efficiency (~26 wt%). This amorphous PtSex (1.2 < x < 1.3) behaves as a fully activated surface, accessible to catalytic reactions, and features a nearly 100% current density relative to a pure Pt surface and reliable production of sustained high-flux hydrogen over a 2 inch wafer as a proof-of-concept. Furthermore, an electrolyser is demonstrated to generate a high current density of 1,000 mA cm−2. Such an amorphization strategy is potentially extendable to other noble metals, including the Pd, Ir, Os, Rh and Ru elements, demonstrating the universality of single-atom-layer catalysts