摘要：The CoCrFeNiMn high entropy alloy was produced by homogenization, cold rolling and recrystallization. The effects of thermomechanical processing on microstructures and tensile properties at different temperatures were investigated using X-ray diffractometry（XRD）, optical microscopy（OM）, scanning electron microscopy（SEM） and multi-functional testing machine. The results show that dendritic structures in cast alloy evolve into equiaxed grains after being recrystallized, with single face-centered cubic（FCC） phase detected. The most refined alloys, stemming from the highest rolling ratio（40%）, exhibit the highest strength due to the grain boundary strengthening, while the variation of elongation with temperature shows a concave feature. For the coarse-grained alloys, both the ductility and work hardening ability decrease monotonically with increasing temperature. Serrated flow observed at intermediate temperatures is attributed to the effective pinning of dislocations, which manifests the occurrence of dynamic strain hardening and results in the deterioration in ductility. Besides, dimples on the fracture surfaces indicate the typical ductile rupture mode.

摘要：Microstructures and mechanical properties of dual-phase AlxCrMnFeCoNi (x=0.4, 0.5, 0.6, at.%) alloys were investigated. Thermomechanical processing leads to a microstructural evolution from cast dendritic structures to equiaxed ones, consisting of face-centered cubic (fcc) and body-centered cubic (bcc) phases in the two states. The volume fraction of bcc phase increases and the size of fcc grain decreases with increasing Al content, resulting in remarkably improved tensile strength. Specifically, the serrated flow occurring at the medium temperatures varies from type A+B to B+C or C as the testing temperature increases. The average serration amplitude of these Al-containing alloys is larger than that of CoCrFeNiMn alloy due to the enhanced pinning effect. The early small strain produces low-density of dislocation arrays and bowed dislocations in fcc grains while the dislocation climb and shearing mechanism dominate inside bcc grains. The cross-slip and kinks of dislocations are frequently observed and high-density-tangled dislocations lead to dislocation cells after plastic deformation with a high strain.

摘要：In order to improve the mechanical properties of *** transition joints manufactured by explosive welding,meshing bonding interfaces were obtained by prefabricating dovetail grooves in base *** microstructure and mechanical properties of the meshing interfaces were systematically *** microstructure observation showed that metallurgical bonding without pores was created in the form of direct bonding and melting zone bonding at the *** on tensile specimens showed cleavage fracture on the steel side and ductile fracture on the aluminum side near the *** tensile shear test results indicated that the shear strength of the meshing interface 0°and 90°was increased by 11%and 14%,respectively,when being compared to that of the ordinary *** transition *** values of microhardness decreased as the distance from the interface *** three-point bending,cracks were observed at the bonding interface for some specimens due to the existence of brittle *** compounds.

摘要：The climate crisis associated with rapid accumulation of carbon dioxide in atmosphere has posed increasing threat to human wellbeings[1].It is of great significance to capture and convert CO2 to realize sustainable utilization of carbon resources[1].The electrocatalytic CO2 reduction reaction(CO2RR)provides a sustainable,carbon-neutral method for solving this *** the difficulty of finding an efficient catalysts slows down the realization of the ambitious *** is mainly because it requires simultaneous optimization of selectivity for a specific product,energy conversion efficiency,current density and stability of the reaction system.

摘要：The binding energy and generalized stacking-fault energy (GSFE) are two critical interface properties of two dimensional layered materials, and it is still unclear how neighboring layers affect the interface energy of adjacent layers. Here, we investigate the effect of neighboring layers by comparing the differences of binding energy and GSFE between trilayer heterostructures (graphene/graphene/graphene, graphene/graphene/boron nitride,boron nitride/graphene/boron nitride) and bilayer heterostructures (graphene/graphene,graphene/boron nitride) using density functional theory. The binding energy of the adjacent layers changes from -2.3% to 22.55% due to the effect of neighboring layer, with a very small change of the interlayer distance. Neighboring layers also make a change from -2% to 10% change the GSFE, depending on the property of the interface between adjacent layers. In addition, a new simple expression is proven to describe the GSFE landscape of graphene-like structure with high accuracy.

摘要：波形整形技术使试样满足应力均匀条件和恒定应变率加载,石英片检测试样两端的应力均匀性,获得微弱的透射信号。对开始加载阶段径向惯性效应带来的轴向应力附加值给予了计算修正,得到了肌肉在不同加载方向和不同应变率下的应力应变曲线。结果发现:肌肉材料的应力应变曲线呈现粘弹性材料所具有的凹向上特征,由最小显著差数法进行统计分析,发现猪后腿肌肉的力学性能对应变率和加载方向都敏感。沿纤维方向压缩时肌纤维易发生压缩失稳,强度比垂直纤维方向低。