Owing to the excellent performance, the generalized cross-spring flexure pivots (GCSFP), formed by two symmetric crossing leaves at an arbitrary position along the radial direction, had been widely used in precision instruments. However, the accuracy of GCSFPs is lower than the required one for some ultra-precision instruments. Especially for the large angles, the axis drift of GCSFPs cannot be ignored. By adding a spring to a GCSFP, a novel flexure pivot, which called generalized triple-cross-spring flexure pivot (GTCSFP), can be obtained. Finite element analysis shows that GTCSFPs can achieve ultra-high precision. The axis drift is less than 0.3 μm for a ±10° motion range. Several prototypes of GTCSFP were designed and manufactured. Rotational stiffness, radial stiffness, axial stiffness, axis drift, temperature drift, and fatigue life were measured. The result shows that GTCSFPs have many advantages, such as high precision, long service life, large movement range, and high off-axis/axial stiffness ratio. Thus, GTCSFPs have potential applications in the field of precision instruments.
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http://dx.doi.org/10.1063/1.4897271 | DOI Listing |
Zhonghua Yan Ke Za Zhi
January 2025
Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Key Laboratory of Eye Diseases, School of Ophthalmology, Shandong First Medical University, Qingdao266071, China.
To evaluate the safety and efficacy of cataract extraction combined with multifocal intraocular lens (IOL) optic implantation in Berger space in school-age children with cataracts. It was a prospective study. The clinical data of school-age children with cataract who underwent cataract extraction combined with multifocal IOL implantation at Qingdao Eye Hospital of Shandong First Medical University from January 2019 to June 2023 were collected.
View Article and Find Full Text PDFSci Data
December 2024
Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China.
Polarization multispectral imaging has advanced significantly due to its robust information representation capability. Imaging application requires rigorous simulation evaluation and experimental validation using standardized datasets. However, the current full-Stokes polarization multispectral images (FSPMI) dataset, while providing simulation data, is limited by image drift and spectral bands.
View Article and Find Full Text PDFBMC Med Imaging
December 2024
National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Background: Current mainstream cardiovascular magnetic resonance-feature tracking (CMR-FT) methods, including optical flow and pairwise registration, often suffer from the drift effect caused by accumulative tracking errors. Here, we developed a CMR-FT method based on deformable groupwise registration with a locally low-rank (LLR) dissimilarity metric to improve myocardial tracking and strain estimation accuracy.
Methods: The proposed method, Groupwise-LLR, performs feature tracking by iteratively updating the entire displacement field across all cardiac phases to minimize the sum of the patchwise signal ranks of the deformed movie.
Radiology
November 2024
From the Department of Medicine, Division of Cardiology (M.U., U.S., M. Shotwell, M. Shetty, D.K.K.) and Department of Radiology (W.F., J.J.), University of Louisville School of Medicine, Rudd Heart & Lung Center, 201 Abraham Flexner Way, Ste 600, Louisville, KY 40202.
A 43-year-old male patient with no known past medical history presented to the emergency department with new-onset bitemporal headache, dizziness, and bilateral lower extremity weakness for 1 day. The patient denied chest pain, shortness of breath, cough, or recent exposure to sick individuals. He was not on any medications and denied alcohol or illicit drug use.
View Article and Find Full Text PDFJ Phys Chem Lett
November 2024
School of Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
A drift-diffusion model is used to investigate the effect of device degradation on current-voltage and impedance measurements of perovskite solar cells (PSCs). Modifications are made to the open-source drift-diffusion software IonMonger to model degradation via an increasing recombination rate during the course of characterization experiments. Impedance spectroscopy is shown to be a significantly more sensitive measure of degradation than current-voltage curves, reliably detecting a power conversion efficiency drop of as little as 0.
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