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The vibration of reactors not only produces noise pollution, but also affects the safe operation of reactors. Giant magnetostrictive materials can generate huge expansion and shrinkage deformation in a magnetic field. With the principle of mutual offset between the giant magnetostrictive force produced by the giant magnetostrictive material and the original vibration force of the reactor, the vibration of the reactor can be reduced. In this paper, magnetization and magnetostriction characteristics in silicon steel and the giant magnetostrictive material are measured, respectively. According to the presented magneto-mechanical coupling model including the electromagnetic force and the magnetostrictive force, reactor vibration is calculated. By comparing the vibration of the reactor with different inserted materials in the air gaps between the reactor cores, the vibration reduction effectiveness of the giant magnetostrictive material is validated.

Extreme events with increasing frequency and intensity are significantly affecting the permafrost environment. Analysis using the ERA5-Land reanalysis data revealed that the permafrost region of the central Qinghai-Tibet Plateau (QTP) experienced the summer heat wave in 2022. Four active layer sites experienced maximum active layer thicknesses (ALT) in 2022 (mean: 207.7 cm), which was 20% higher than the mean ALT during 2000–2021 (mean: 175.9 cm). The mean annual ground temperature (MAGT) observed in 2022 was also the highest, exceeding the average of the previous years by 10%. The contribution fraction of heat wave to the seasonal thaw depth of active layer was quantified using Stefan model with ranging from 6.6% to 13.6%, and the maximum contribution fraction occurs in 2022. These findings are helpful to better understand the impact processes of extreme events on the active layer and permafrost. [ABSTRACT FROM AUTHOR]

One of the primary concerns in the field of seismic risk assessment for underground structures is establishing an accurate connection between seismic intensity and structural responses. The objective of this work is to conduct a rational support vector machine (SVM) model for generating mass data and improved fragility curves of cross-fault hydraulic tunnels (CFHTs). The results highlight that the 900 sets, multiple earthquake intensity measures, and cubic polynomial kernel function of the SVM model can improve reliability in evaluating structural performance. Additionally, the improved Cloud analysis method is more suitable for seismic performance than the typical Cloud analysis. [ABSTRACT FROM AUTHOR]

Introduction: Maternal obesity, a health condition increasingly prevalent worldwide, has been suggested to be associated with a higher risk of birth defects in offspring, whereas evidence from population‐based data from China was largely lacking. Additionally, the role of gestational diabetes in the association between maternal obesity and birth defects remains unclear. We aimed to investigate the association of maternal pre‐pregnancy overweight or obesity with any and different types of birth defects in offspring and the interaction between pre‐pregnancy overweight or obesity and gestational diabetes. Material and methods: We conducted a population‐based cohort study including 257 107 singletons born between 2015 and 2021 in Longgang District, Shenzhen, China, using data from the Shenzhen Maternal and Child Health Management System. Poisson regression was conducted to estimate the associations of maternal pre‐pregnancy overweight or obesity, as well as the interaction between pre‐pregnancy overweight or obesity and gestational diabetes, with the risk of birth defects. Models were adjusted for maternal age at delivery, educational level, type of household registration, and gravidity. Results: Maternal pre‐pregnancy overweight was associated with a higher risk of any birth defect (risk ratio [RR] 1.21, 95% confidence interval [CI] 1.12 to 1.31) as well as of congenital malformations of the circulatory system (RR 1.26, 95% CI 1.12 to 1.41), eye/ear/face/neck (RR 1.42, 95% CI 1.04 to 1.94), and musculoskeletal system (RR 1.21, 95% CI 1.01 to 1.44). Maternal pre‐pregnancy obesity was associated with a higher risk of any birth defect (RR 1.38, 95% CI 1.18 to 1.63) and congenital malformations of the circulatory system (RR 1.61, 95% CI 1.30 to 1.98). Infants born to overweight or obese mothers with gestational diabetes had a higher risk of congenital malformations of the circulatory system than infants born to overweight or obese mothers without gestational diabetes. Conclusions: Maternal pre‐pregnancy overweight or obesity was associated with a higher risk of birth defects, particularly congenital malformations of the circulatory system, in offspring. Gestational diabetes interacts additively with pre‐pregnancy overweight or obesity on modifying the risk of congenital malformations of the circulatory system. The importance of improving weight management and assessment of glucose and metabolic functions was emphasized among women planning for pregnancy who are overweight or obese. [ABSTRACT FROM AUTHOR]