Magnetoelastic bending and snapping of ferromagnetic plates in oblique magnetic fields

Ferritic stainless steel has been considered for structural components such as first walls and blankets of fusion power reactors because the material shows low rates of irradiation swelling. Since it is magnetizable, the magnetoelastic interaction between magnetic field and deformation of the structures in a fusion reactor is so strong that their safety is of concern due to the magnetoelastic bending, buckling and magnetic damping, etc. Basic research of the magnetoelastic characteristics of ferromagnetic plate has been paid special attention by researchers. In this paper, the magnetoelastic bending and snapping are studied for a ferromagnetic plate in an oblique magnetic field. The theoretical model is based on the variational principle where the functional is employed as real total energy in the system including external work. The obtained expression of magnetic force on the plate is the same as that derived from the dipole model when the total magnetic field in the ferromagnetic medium is considered. In order to effectively solve the nonlinearly coupled interaction problem between magnetic field and mechanical deformation, a numerical program combining the finite element method for analyzing the magnetic field with the finite difference technique for finding out the bending deformation of the plate is employed to obtain the solution of magnetoelastic bending of a soft ferromagnetic plate. The numerical calculations are carried out for the typical example of a ferromagnetic cantilevered beam-plate in an oblique magnetic field. From the bending curves, that is the tip deflection versus applied magnetic fields, the critical magnetic field for the magnetoelastic snapping is predicted by the Southwell plot. The theoretical predictions show that the critical magnetic field decreases with the increase in incident angle of the oblique magnetic field. By the effect of incident angle on the magnetic buckling, the discrepancy between theoretical and experimental data can be explained well.     

鱼油补充对中老年人群炎性衰老及相关疾病有益作用的研究进展

鱼油富含n-3多不饱和脂肪酸（n-3 polyunsaturated fatty acids, n-3 PUFA）,特别是人体必需脂肪酸二十二碳六烯酸（docosahexaenoic acid, DHA）和二十碳五烯酸（eicosapentaenoic acid, EPA）。DHA和EPA在体内可以衍生出具有抗炎作用的二十碳体,如前列腺素（prostaglandins, PGs）、血栓素（thromboxanes, TX）、消退素（resolvins, Rv）、白三烯（leukotrienes, LTs）和其他氧化衍生物等。且鱼油补充有助于人体炎性衰老相关因子（血清 IL-6、IL-1、TNF-α及 CRP）水平的降低,并对炎性衰老相关疾病具有积极预防效果。本文系统介绍了DHA、EPA二十碳体的衍生及与二十碳四烯酸（arachidonic acid, AA）衍生的关系。同时基于鱼油补充与人体炎性衰老相关因子的关系,总结了膳食鱼油在改善中老年人群心血管疾病、类风湿关节炎、认知障碍及2型糖尿病的作用。已有数据显示,鱼油在降低炎性衰老因子,血脂异常改善和类风湿性关节炎症状减轻方面具有积极的临床效果。但是,在认知功能障碍和2型糖尿病改善方面,尚缺乏充分的治疗或者预防作用相关证据。     

Review of the applications of metabolomics approaches in dairy science: From factory to human

Dairy products are nutritious and are increasingly consumed as an important dietary component in China. Exploring the factors that affect the nutritional quality of dairy products and ensuring their safety have become the main focus of dairy research. The composition of metabolites in dairy products is large and complex. The levels and types of metabolites vary according to various factors in the process from factory to human dining table. Therefore, metabolites might be used to assess the nutritional value, traceability and authenticity, and physiological function of dairy products. This review's main goal is to introduce the most recent developments and applications of metabolomics as an efficient tool for comprehensively characterising the composition and dynamic changes of metabolites in the area of food science and nutrition research in the process of getting dairy products from factory to human. The examples are taken from the most relevant metabolomics work published from 2018 to 2022, focusing on potential marker metabolites and metabolic mechanisms related to dairy product quality, authenticity/traceability and dairy intake monitoring. The future direction of metabolomics in the field of dairy science was also discussed. This information will provide a reference for the further application of metabolomics technology to Chinese dairy products to develop their quality, safety and nutritional value.