This study of nonlinear dynamics includes (i) an identification of quasi-steady states of response using equivalent linearization, (ii) the temporal simulation of the system using Heun's time step procedure on time domain analytic signals, and (iii) a laboratory experiment. An attempt has been made to select material and measurement parameters so that nearly the same systems are used and analyzed for all three parts of the study. This study illustrates important features of nonlinear response to narrow band excitation: (a) states of response that the system can acquire with transitions of the system between those states, (b) the interaction between the noise source and the vibrating load in which the source transmits energy to or draws energy from the load as transitions occur; (c) the lag or lead of the system response relative to the source as transitions occur that causes the average frequencies of source and response to differ; and (d) the determination of the state of response (mass or stiffness controlled) by observation of the instantaneous phase of the influence function. These analyses take advantage of the use of time domain analytic signals that have a complementary role to functions that are analytic in the frequency domain.
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Rev Alerg Mex
December 2024
Departamento de Inmunología, Hospital Infantil de Especialidades de Chihuahua; Facultad de Medicina y Ciencias Biomédicas, Universidad Autónoma de Chihuahua.
Background: 22q11 deletion syndrome consists of a variable grouping of phenotypic features and immunological defects secondary to the loss of genetic material located in the 22q11.2 band. The 22q11 deletion spectrum encompasses different syndromes related to the same etiology and with overlapping anomalies, including DiGeorge syndrome, velocardiofacial syndrome, among others.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
McKetta Department of Chemical Engineering and Texas Material Institute, The University of Texas at Austin, Austin, Texas 78712, United States.
Germanium (Ge) colloidal quantum dots (CQDs) were synthesized by thermal decomposition of GeI using capping ligand mixtures of oleylamine (OAm), octadecene (ODE), and trioctylphosphine (TOP). Average diameters could be tuned across a wide range, from 3 to 18 nm, by adjusting reactant concentrations, heating rates, and reaction temperatures. OAm promotes decomposition of GeI to Ge and serves as a weakly bound capping ligand.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Center for Nanoscience and Sustainable Technologies (CNATS), Universidad Pablo de Olavide, 41013 Seville, Spain.
The proton bond is a pivotal chemical motif in many areas of science and technology. Its quantum chemical description is remarkably challenged by nuclear and charge delocalization effects and the fluxional perturbation that it induces on molecular substrates. This work seeks insights into proton bonding at sub-kelvin temperatures.
View Article and Find Full Text PDFSci Rep
January 2025
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
In recent years, research on chiral bound states in the continuum (BIC) has surged, leading to the development of various chiral metasurfaces with narrow bandwidths by breaking of in-plane and out-of-plane symmetries. However, the ability to dynamically tune the working band remains relatively unexplored, which is valuable for chiral sensing applications. Optical phase-change materials, with tunable dielectric constants and switchable properties during phase transition, offer the potential for dynamic control of optical metasurfaces.
View Article and Find Full Text PDFJ Cancer
January 2025
Department of Mechanical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
Band selection is a common approach to reduce the data dimensionality of hyperspectral imagery. It extracts several bands of importance in some sense by taking advantage of high spectral correlation. In medical imaging, narrow-band imaging (NBI) is an imaging technique for endoscopic diagnostic medical tests, where light of specific blue and green wavelengths is used to enhance the detail of certain aspects of the surface of the mucosa.
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