Luminescence of Ce3+ at two different sites in ?-Sr2P2O7 under vacuum ultraviolet-UV and x-ray excitation

A series of Ce3+ doped ?-Sr2?2xCexNaxP2O7 phosphor compounds has been prepared using a high-temperature solid-state reaction technique. The luminescence properties under vacuum ultraviolet-UV and x-ray excitation were studied. Luminescence spectra reveal three UV-emitting peaks at about 310, 330, and 350 nm from which we conclude that Ce3+...

Insight into Eu redox and Pr³⁺ 5d emission in KSrPO₄ by VRBE scheme construction

A series of Ln-doped KSrPO₄ (Ln = Ce³⁺, Eu³⁺, Eu²⁺, Pr³⁺) phosphors are prepared through a high-temperature solid-state method. The KSrPO₄ compound is confirmed to possess a β-K₂SO₄ structure with the Pnma group by Rietveld refinement, and the temperature...

Construction safety during pandemics: Learning from the xinjia express hotel collapse during covid-19 in china

Many construction accidents occur in China each year, leading to a large number of deaths, injures, and property losses. Due to the outbreak of COVID-19, little attention is paid to construction safety, resulting in severe accidents. To prevent construction accidents and learn to how address safety issues in future pandemics, this study...

DisQ: Disentangling Quantitative MRI Mapping of the Heart

Quantitative MRI (qMRI) of the heart has become an important clinical tool for examining myocardial tissue properties. Because heart is a moving object, it is usually imaged with electrocardiogram and respiratory gating during acquisition, to “freeze” its motion. In reality, gating is more-often-than-not imperfect given the heart rate...

Visualized analysis of safety climate research: A bibliometric data mining approach

It is well known that safety climate (SC) has paramount significance in safety science and accident prevention. In this paper, a bibliometric data mining is conducted to systematically review the research domain of SC. Overall, 1624 documents on SC are obtained, covering 4830 authors, 473 journals, 89 countries/regions, and 1766 institutions...

Influence of unilateral low adhesion on transient wheel-rail rolling contact and wheel damages

A time-domain finite element model is developed to study the transient rolling contact of a driving wheelset over a curved track with Low Adhesion Zones (LAZs) shorter than 1.0 m. LAZs on one rail, i.e., unilateral LAZs occurring more likely, is treated for a speed up to 500 km/h. Structural vibrations of wheelset are analyzed to explain the...