A efficient time-domain algorithm, based on the spatial pulse response approach, is proposed for the determination of the acoustic fields radiated by means of acoustical sources. The computations are performed by the discrete representation array modelling (DREAM) procedure, specially adapted to study the planar and arbitrarily structured multielement transducer arrays. DREAM, based on the discrete representation computational concept, acts as the generator of the array velocity potential impulse response, and thus, does not require any analytical solutions prior to the computations. The computations are valid for all field regions and may be performed for any excitation form. Apart from the classic case of rigid baffle conditions, the free and soft planar baffle also can be considered. The use of the time-domain solution for causal Green's function for lossy media enables the wideband absorption effects to be modeled. The accuracy of computations depends on temporal and spatial discretization and can be obtained as required. The quantitative rules, which determine the required discretizations to be predicted, are proposed. The computational examples show that DREAM allows the different and various transducers to be modeled. Its possibilities are illustrated by computations for the multielement transducers, including the beam-steered, amplitude-weighted sonar array, the focusing annular transducer, and the diverging and converging cylindrical array.
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http://dx.doi.org/10.1109/58.753032 | DOI Listing |
J Chem Theory Comput
January 2025
Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa K1N 6N5,Canada.
The combined density functional theory and multireference configuration interaction (DFT/MRCI) method is a semiempirical electronic structure approach that is both computationally efficient and has predictive accuracy for the calculation of electronic excited states and for the simulation of electronic spectroscopies. However, given that the reference space is generated via a selected-CI procedure, a challenge arises in the construction of smooth potential energy surfaces. To address this issue, we treat the local discontinuities that arise as noise within the Gaussian progress regression framework and learn the surfaces by explicitly incorporating and optimizing a white-noise kernel.
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State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065, China. Electronic address:
High-performance green functional materials have garnered significant interest for electromagnetic interference (EMI) shielding applications, but creating customized, low-density, high-strength and high-efficiency biomass-based shielding materials remains challenging. In this study, lightweight Ca doped sodium alginate (SA) porous scaffolds with a carbon nanotube (CNT)/graphene (Gr) hybrid conductive network were fabricated via direct ink writing (DIW) 3D printing. The SA/CNT/Gr inks with unique rheological properties were formulated and architectures with arbitrarily customized structures could be freely constructed based on the printable inks.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Leibniz University Hanover: Leibniz Universitat Hannover, Institute for Solid State Physics, GERMANY.
Graphdiyne (GDY) has been considered a promising electrode material for application in electrochemical energy storage. However, studies on GDY featuring an ordered interlayer stacking are lacking, which is supposed to be another effective way to increase lithium binding sites and diffusion pathways. Herein, we synthesized a hydrogen-substituted GDY (HsGDY) with a highly-ordered AA-stacking structure via a facile alcohol-thermal method.
View Article and Find Full Text PDFSensors (Basel)
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The State Key Laboratory for the Safety, Long-Life, Health Operation and Maintenance of Long-Span Bridges, Jiangsu Provincial Institute of Traffic Science (JSTI Group), Nanjing 210098, China.
The strain data acquired from structural health monitoring (SHM) systems of large-span bridges are often contaminated by a mixture of temperature-induced and vehicle-induced strain components, thereby complicating the assessment of bridge health. Existing approaches for isolating temperature-induced strains predominantly rely on statistical temperature-strain models, which can be significantly influenced by arbitrarily chosen parameters, thereby undermining the accuracy of the results. Additionally, signal processing techniques, including empirical mode decomposition (EMD) and others, frequently yield unstable outcomes when confronted with nonlinear strain signals.
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