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Vibration measurement, particularly mode shape measurement, is an important aspect of structural dynamic analysis since it can validate finite element or analytical vibration models. Scanning laser Doppler vibrometry (LDV) and high-speed digital image correlation have become dominant methods for experimental mode shape measurement. However, these methods have high equipment costs and several disadvantages regarding spatial or temporal performance. This paper proposes a laser Doppler vibrometer induced stroboscopic digital image correction for non-contact mode shape and operational deflection shape measurement. Our results verify that single-point LDV and normal rate cameras can be used obtain high spatial resolution mode shape and operational deflection shape. Measurement frequency range is much higher than the camera capturing rate. We also show that the proposed approach coincides well with time-averaged electronic speckle pattern interferometry.
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http://dx.doi.org/10.1364/OE.436196 | DOI Listing |
Int J Numer Method Biomed Eng
September 2025
Department of Industrial and Manufacturing Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.
The screw-retained implant-supported crown is a durable, aesthetic restoration, but debonding between the crown and abutment remains a challenge to survivability. The purpose of this work was to devise an abutment shape that can be embedded into the crown while the crown is being additively manufactured. The result was a mechanically retained, no-adhesive abutment and crown unit that is mounted to the implant fixture.
View Article and Find Full Text PDFGlob Chang Biol
September 2025
State Key Laboratory of Vegetation Structure, Function and Construction (VegLab), Institute of Ecology, and College of Urban and Environmental Sciences, Peking University, Beijing, China.
Increasingly frequent extreme droughts pose a serious threat to global vegetation. However, previous studies have not characterized the whole response process of vegetation to drought, and there are uncertainties in their methods and indicators. In this study, we developed a new indicator system and derived the response modes of global vegetation to extreme drought.
View Article and Find Full Text PDFThe human mind constructs and updates models of events during comprehension. Event models are multidimensional, multi-timescale, and structured. They enable prediction, shape memory formation, and facilitate action control.
View Article and Find Full Text PDFThe development of novel optical self-healing materials holds significant importance for applications in anticounterfeiting and information encryption, but remains a formidable challenge. This study presents a fluorescent self-healing material designed for 2D/3D printing anticounterfeiting applications, exhibiting outstanding properties such as high transmittance, excellent mechanical strength, and remarkable self-healing efficiency. The triple dynamic bond networks provide robust mechanical and self-healing capabilities, with the polymer demonstrating a tensile strength of 26.
View Article and Find Full Text PDFJ Affect Disord
September 2025
Department of Psychology, Palo Alto University, Palo Alto, CA, United States; Neuroscience Program, SRI International, Menlo Park, CA, United States.
Functional network connectivity (FNC) among large-scale brain networks-including the default mode (DMN), frontoparietal (FPN), and salience (SN) networks-have been increasingly implicated in transdiagnostic features of mental health disorders. In this study, we examined FNC patterns among the DMN, FPN, SN, and nine additional large-scale networks using resting-state functional MRI (rs-fMRI) data from 7760 adolescents (ages 10-13) from the Adolescent Brain Cognitive Development (ABCD) study. We investigated whether altered connectivity among these networks was associated with symptoms of social anxiety, as reported by caregivers at the two-year follow-up visit.
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