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We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.
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http://dx.doi.org/10.1063/1.4825342 | DOI Listing |
J Chem Phys
September 2025
Smoluchowski Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
An improved rotational characterization of the E3Σ1+(63S1) Rydberg state of the CdAr diatom produced in a supersonic beam and studied using laser induced fluorescence (LIF) excitation spectra is presented. As an example, the spectra of the E3Σ1+←A3Π0+(53P1) transition, originating from the excitation of a single 116Cd40Ar isotopologue, are recorded and analyzed. In the experiment, the optical-optical double resonance method is employed, utilizing the E3Σ1+(υ')←A3Π0+(53P1)(υ″=6)←X1Σ0+(υ=0) scheme.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2025
Department of Chemistry and Sustainable Technology, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland.
Accurate thermodynamic calculations for aluminum alkyls require proper treatment of low-frequency vibrations poorly described by the harmonic approximation (HA). Here, we present a systematic investigation of hindered rotation and out-of-plane bending in aluminum trichloride (ATC) and its methyl derivatives, employing advanced computational methods to perform anharmonic entropy corrections, such as torsional eigenvalue summation (TES), the extended two-dimensional torsion method (E2DT), the multi-structural approximation with torsional anharmonicity (MS-T), and Fourier grid Hamiltonian (FGH). Our results reveal distinct structure-dependent behaviors: monomers exhibit near-free methyl rotations where the HA overestimates entropy by 20-30 J K mol, while dimers show more hindered rotations adequately described by the HA around room temperature.
View Article and Find Full Text PDFISA Trans
August 2025
School of Automation, Shenyang Aerospace University, Shenyang, Liaoning Province 110136, China. Electronic address:
When a failure occurs in bearings, vibration signals are characterized by strong non-stationarity and nonlinearity. Therefore, it is difficult to sufficiently dig fault features. 1D local binary pattern (1D-LBP) has the advantageous feature to effectively extract local information of signals.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Soochow Institute for Energy and Materials Innovations, College of Energy, Soochow University, Suzhou 215006, P. R. China.
Electrocatalytic CO reduction (eCOR) under acidic conditions is the game changer of resourceful CO utilization owing to the alleviated carbon loss but faces severe competition from the hydrogen evolution reaction (HER) that greatly curtails the electric current efficiency. Leveraging the eCOR side of the teeterboard calls for a fundamental understanding of the triphasic electrode process involving a complex arrangement of electric double layers (EDLs). Herein, a series of model catalysts with tailored cavernous parameters are fabricated to geometrically and spectroscopically decipher the competing HER and eCOR processes that engage different proton sources.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
School of Biomedical Engineering, Shenzhen Key Laboratory for Nano-Biosensing Technology, Guangdong Key Laboratory of Biomedical Measurements and Ultrasound Imaging, Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen 518060, China.
Electrochemiluminescence (ECL) is rapidly emerging as an excellent electrochemical analytical technique for the specific and sensitive detection of various biomarkers and hazardous trace metals. Among ECL emitters, gold nanoclusters (AuNCs) have proven to be excellent luminophores due to their remarkable luminescent properties, stability, and biocompatibility. However, the low ECL efficiency of AuNCs precludes their application in ultrasensitive biosensing.
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