In practical engineering applications, the vibration is often generated in various directions and can be harmful to the engineering equipment. Thus, it is necessary to develop vibration isolators that can reduce vibration in multiple directions. In this paper, we propose a planar two-dimensional vibration isolator based on compliant mechanisms. The proposed mechanism consists of two negative stiffness-compliant modules and two positive stiffness-compliant modules, which leads to the quasi-zero stiffness (QZS) property in the mechanism. The dynamic model is established by using the third-order Taylor expansion and the harmonic balance method. Based on the dynamic model, the influence of different parameters on the displacement transmissibility is discussed, including damping ratio, system stiffness, and excitation amplitude. Finally, we conducted the vibration isolation experiments and obtained the displacement transmissibility of the isolator. The results verify that the proposed isolator has good isolation performance for low-frequency vibration.
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Micromachines (Basel)
December 2024
School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China.
In practical engineering applications, the vibration is often generated in various directions and can be harmful to the engineering equipment. Thus, it is necessary to develop vibration isolators that can reduce vibration in multiple directions. In this paper, we propose a planar two-dimensional vibration isolator based on compliant mechanisms.
View Article and Find Full Text PDFNat Commun
January 2025
Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG-PHELIQS, 38000, Grenoble, France.
Hybrid superconductor-semiconductor Josephson field-effect transistors (JoFETs) function as Josephson junctions with gate-tunable critical current. Additionally, they can feature a non-sinusoidal current-phase relation (CPR) containing multiple harmonics of the superconducting phase difference, a so-far underutilized property. Here we exploit this multi-harmonicity to create a Josephson circuit element with an almost perfectly π-periodic CPR, indicative of a largely dominant charge-4e supercurrent transport.
View Article and Find Full Text PDFAnalyst
January 2025
Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu Province 215123, China.
The choices of matrices and protocols for sample deposition are critical factors, which impact each other in the matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI). Previous reports on MALDI MS matrices have only compared their performances in terms of their MS signal intensities and provided optical microphotos or MALDI MS images of sample spots but typically lacked quantitative evaluation. Therefore, there is an urgent need to develop a multivariate model to evaluate the performance of different combinations of matrices and sample protocols.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
We report an experimental study on how topological defects induced by cylindrical air inclusions in the ferroelectric nematic liquid crystal RM734 are influenced by ionic doping, including an ionic surfactant and ionic polymer. Our results show that subtle differences in molecular structure can lead to distinct surface alignments and topological defects. The ionic surfactant induces a planar alignment, with two -1/2 line defects adhering to the cylindrical bubble surface.
View Article and Find Full Text PDFNanoscale
January 2025
Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China.
Two-dimensional materials with a combination of a moderate bandgap, highly anisotropic carrier mobility, and a planar structure are highly desirable for nanoelectronic devices. This study predicts a planar BeP monolayer with hexagonal symmetry that meets the aforementioned desirable criteria using the CALYPSO method and first-principles calculations. Calculations of electronic properties demonstrate that the hexagonal BeP monolayer is an intrinsic semiconductor with a direct band gap of approximately 0.
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