Magnetoresistance and exchange bias in high Mn content melt-spun Mn_(46)Ni_(42)Sn_(11)Sb_1 alloy ribbon

Highly textured Heusler alloy Mn_（46）Ni_（42）Sn_（11）Sb_1 ribbons were prepared by melt spinning. The annealed high Mn content Mn46Ni42Sn11Sb1 ribbon cross-section microstructure, crystal structure, martensitic transformation（MT）, and magnetoresistance（MR） properties were investigated. The MR in the annealed ribbon was assessed by the magnetic field direction perpendicular to the ribbon surface with the magnetic field up to 30 k Oe. The large negative value of 25% for MR was obtained at 244 K. The exchange bias（EB） effects of the as-spun and annealed ribbons were investigated. After annealing, the EB effects have been improved by about 25 Oe at the temperature of 50 K. The magnetizations have increased approximately by 10% more than the as-spun ribbon.

Recent advances in designing conductive hydrogels for flexible electronics

Flexible electronics have emerged as an exciting research area in recent years,serving as ideal interfaces bridging biological systems and conventional electronic devices.Flexible electronics can not only collect physiological signals for human health monitoring but also enrich our daily life with multifunctional smart materials and devices.Conductive hydrogels(CHs)have become promising candidates for the fabrication of flexible electronics owing to their biocompatibility,adjustable mechanical flexibility,good conductivity,and multiple stimuli-responsive properties.To achieve on-demand mechanical properties such as stretchability,compressibility,and elasticity,the rational design of polymer networks via modulating chemical and physical intermolecular interactions is required.Moreover,the type of conductive components(eg,electron-conductive materials,ions)and the incorporation method also play an important role in the conductivity of CHs.Electron-CHs usually possess excellent conductivity,while ion-CHs are generally transparent and can generate ion gradients within the hydrogel matrices.This mini review focuses on the recent advances in the design of CHs,introducing various design strategies for electron-CHs and ion-CHs employed in flexible electronics and highlighting their versatile applications such as biosensors,batteries,supercapacitors,nanogenerators,actuators,touch panels,and displays.

Special issue： Near-net shaping technology

Near-net shaping is an efficient, economical and environmentally-friendly approach to manufacture products which are very close to the final shape, reducing the need for surface finishing. It has become more and more important to use raw materials and energy in an optimal way. Near-net shaping technology has attracted increasing attention in both academic and industrial communities, especially in China, because China has become the world＇s largest regional market for main material forming methods, such as casting, forging and injection molding. The main objective of this special issue in Frontiers of Mechanical Engineering is to bring together the leading ideas, experience and research results of academic scientists and researchers on various aspects of near-net shaping technology. This special issue contains eleven papers contributed by prestigious experts from different countries, including four reviews and seven research articles. These papers cover a broad area of the near-net shaping technology,