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The suspension of porous particles in fluids occurs widely in various natural and industrial processes. However, the sedimentation behavior of porous particles is not extensively understood as the solid impermeable counterparts. In this work, the drafting–kissing–tumbling (DKT) phenomenon in a narrow channel containing porous particles is investigated by the multi-relaxation-time (MRT) lattice Boltzmann method (LBM). The initial particle spacing L p * (1.5 ∼ 6) and Darcy number Da (8 × 10 − 6 ∼ 6 × 10 − 2 ) are examined on the sedimentation process of two particles under three initial arrangements, i.e., the trailing particle is porous (case 1), the leading particle is porous (case 2), and both the particles are porous (case 3). The results show that the presence of porous particles can enhance the interactions between two particles, and increasing the penetrability reduces the particle drag force to accelerate sedimentation. The drafting time is insensitive to Da at small L p * , and it decreases with Da at large L p * in cases 1 and 3 while it changes to increase with Da in case 2. A phase diagram with respect to Da and L p * is further extracted to identify three sedimentation modes of particle pairs. It is found that the transition between the one-off DKT and repeated DKT modes is not affected by L p * in cases 2 and 3, while the critical condition for the non-DKT and one-off DKT modes depends strongly on Da and L p * in case 2. [ABSTRACT FROM AUTHOR]

This study aims to explore the effects of eye exercises on the accommodative ability of Chinese school-aged children. Methods: This study used a convenience cluster sampling and selected 149 students from grades 2– 5 in a Wenzhou primary school to participate in the intervention in June 2022. This study involved a one-month intervention teaching eye exercises using a composite feedback model. Assessments were made at 3 and 9 months post-intervention. Data collection occurred thrice, including a baseline and two follow-ups, measuring monocular and binocular accommodative facility, monocular and binocular accommodative amplitude, CISS scale, spherical equivalent refraction, and uncorrected visual acuity. Analysis used chi-square tests and generalized estimating equations to evaluate the exercises' effectiveness, with a significance threshold of P < 0.05. Results: 134 students completed the follow-up, including 61 females (45.52%). After teaching intervention, students showed significant improvements in the accuracy of manipulation, rhythm, acupoint location, strength effectiveness and rhythm of acupressure eye exercises (all P < 0.05), with increases of 10.37%, 13.03%, 16.96%, and 25.17%, respectively. Follow-up assessments revealed both monocular and binocular accommodative amplitude at T3 were significantly higher than at T1 and T2. Moreover, the binocular accommodative amplitude in the high-quality eye exercise group remained significantly higher than that in the low-quality group even(B=1.39,1.46, P < 0.01). Eye exercises could improve monocular and binocular accommodative amplitude in the short term(P < 0.05). High-quality eye exercises could alleviate visual fatigue (B=− 2.00--3.49, both P < 0.05). However, eye exercises did not demonstrate any advantages in affecting spherical equivalent refraction or uncorrected visual acuity (P > 0.05). Conclusion: Eye exercises can alleviate myopia-related symptoms in Chinese children aged 7 to 11 years. However, this study did not find that eye exercises effectively reduce the degree of myopia in children. Trial Registration: The original trial (Registration site: https://www.chictr.org.cn/ Registration number: ChiCTR2300070903) was retrospectively registered on 26/04/2023. [ABSTRACT FROM AUTHOR]

Sandwich structures have been increasingly used in aerospace engineering, while local vibration modes of sandwich plates might occur earlier than global vibration modes attributing to the weak stiffness of the core layer, and it is difficult to predict such vibration modes. Therefore, local vibration modes are often discarded in the process of structural design, so that potential dangers might be encountered when the frequency of external load is close to the natural frequency of local vibration. To avoid such an issue, an extended Legendre higher-order theory (ELHT) is developed to accurately forecast the local dynamic behaviors of sandwich plates for the first time. Subsequently, an effective multi-objective optimization platform will be constructed to optimize the distribution of graphene-nanoplatelets (GPLs) in the core layer, so that natural frequencies of local vibration modes will be improved and largely more than the fundamental frequency. The B-spline basis functions are employed to describe various GPLs distributions, which is more convenient to produce original data for the machine learning method in the optimization process. Then, extreme gradient boosting optimized by Sparrow Search Algorithm (SSA-XGBoost) is utilized as the high-fidelity surrogate model to construct the objective functions to accelerate the interaction of the ELHT and non-dominated sorting sparrow search algorithm (NSSSA). By optimizing for minimum global and local fundamental frequency ratio and total mass of GPLs reinforced sandwich plates, the Pareto-optimal solutions are obtained from the present algorithm which can give an alternative suggestion for the future designer to ensure the structural dynamic safety of thick sandwich plates. [ABSTRACT FROM AUTHOR]