经济型铁素体/贝氏体高扩孔钢的组织与性能

 通过TMCP工艺实验,研究了Si、Mn含量对低碳Si Mn钢显微组织、力学及成形性能的影响,探讨了铁素体/贝氏体双相钢(FB钢)在扩孔过程中的裂纹形成及扩展行为。研究结果表明,增加Si含量,实验钢中等轴铁素体的体积分数增加,扩孔性能得到改善;而增加Mn含量,实验钢的强度和韧性显著提高,但塑性和扩孔性能有所下降。FB钢中的裂纹扩展主要是以微孔聚集机制进行,当遇到贝氏体时,裂纹通过铁素体 贝氏体相界面并剪断铁素体进行扩展。合理选择Si、Mn含量和TMCP工艺参数,可以获得690 MPa级的经济型热轧FB高扩孔钢,扩孔率达到了95%,综合性能较好。     

Multiple defects induced near-infrared self-luminescence of (Ca,Sr)LaMgTaO6 double perovskite phosphor

Conventional near-infrared luminescent phosphors activated by transition metal elements or rare earth activators were already widely reported. In this work, we develop a self-activated near-infrared luminescent phosphor with a typical double perovskite structure, which exhibits an emission at 650–750 nm under excitation at 365 nm. The origin of the desired luminescence in (Ca,Sr)LaMgTaO₆ compounds is attributed to the oxygen vacancies defects, oxygen interstitial defects and substitution defects and antioccupation defects. Thermal quenching of photoluminescence is undesirable with an integrated emission loss of 30–50% at 150 °C, which needs to be improved. This new series of near-infrared luminescent materials have potential applications in agricultural cultivations and bio-imaging materials. More importantly, we demonstrate a strategy by self-activation to realize near-infrared light.     

Defect-rich high-entropy oxide nanospheres anchored on high-entropy MOF nanosheets for oxygen evolution reaction

In this work, high-entropy oxide nanoparticles (HEO NPs)/high-entropy metal-organic framework (HE-MOF) heterostructure electrocatalysts for oxygen evolution reaction (OER) are constructed by in-situ growth of HEO NPs on HE-MOF using partial-localized pyrolysis strategy, and the effect of pyrolysis temperature on the OER performance are studied. The results indicate that the well-dispersed HEO NPs are rich in defects such as oxygen vacancy and lattice distortion, which can increase catalytic active centers. Meanwhile, the nanosheet-like HE-MOF not only acts as the support HEO NPs catalyst but also is kinetically beneficial for fast electrons and ions transportation. Among all the prepared nanostructures, HE-MOF-350-200 shows the best OER performance, achieving a low overpotential of 266 mV at 50 mA cm⁻² along with a satisfactory stability.