碱性水电解(AWE)作为一种具有工业应用前景的绿色制氢方法,能够用来改善能源短缺和环境污染问题.然而,由于电极材料昂贵且效率低下,这种方法生产氢气的效率比较低.本文采用块状AlCoCrFeNi高熵合金作为碱性电解水的有效电极.研究发现通...碱性水电解(AWE)作为一种具有工业应用前景的绿色制氢方法,能够用来改善能源短缺和环境污染问题.然而,由于电极材料昂贵且效率低下,这种方法生产氢气的效率比较低.本文采用块状AlCoCrFeNi高熵合金作为碱性电解水的有效电极.研究发现通过快速阳极氧化(5 min)处理的高熵合金可以同时对析氢和析氧反应(HER和OER)具有超高的催化活性,只需要880和845 m V的过电位就可以达到-500 mA cm-2(HER)和500 mA cm-2(OER)的电流密度.特别地,该催化剂只需要3.00 V就可以达到500 mA cm-2的全解水电流密度,并且在此电流密度下表现出超过100小时的出色稳定性.我们的研究表明,阳极氧化的块体AlCoCrFeNi高熵合金作为高效催化剂在工业水电解制氢中具有广阔的应用前景,有望用于缓解环境问题和能源危机.展开更多
In this work, analysis of electromigration-induced void morphological evolution in solder interconnects is performed based on mass diffusion theory. The analysis is conducted for three typical experimentally observed ...In this work, analysis of electromigration-induced void morphological evolution in solder interconnects is performed based on mass diffusion theory. The analysis is conducted for three typical experimentally observed void shapes: circular, ellipse, and cardioid. Void morphological evolution is governed by the competition between the electric field and surface capillary force. In the developed model, both the electric field and capillary force on the void's surface are solved analytically. Based on the mass conversation principle, the normal velocity on the void surface during diffusion is obtained. The void morphological evolution behavior is investigated, and a physical model is developed to predict void collapse to a crack or to split into sub-voids under electric current. It is noted that when the electric current is being applied from the horizontal direction, a circular void may either move stably along the electric current direction or collapse to a finger shape, depending on the relative magnitude of the electric current and surface capillary force. However, the elliptical-shaped void will elongate along the electric current direction and finally collapse to the finger shape. On the other hand, the cardioid-shaped void could bifurcate into two sub-voids when the electric current reaches a critical value. The theoretical predictions agree well with the experimental observations.展开更多
The magneto-impedance(MI) effect in amorphous and current annealed Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 wires has been measured to investigate the influence of DC annealing,highcurrent-density electropulsing annealing and te...The magneto-impedance(MI) effect in amorphous and current annealed Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 wires has been measured to investigate the influence of DC annealing,highcurrent-density electropulsing annealing and tensile stress applied during annealing process.The results showed that the MI of DC annealed sample exhibits a sharp maximum.The Maximum MI ratio of 60%was observed in the sample of high-current-density electropulsing annealed under applied tensile stress.展开更多
基金supported by the Multi-Year Research Grants(MYRG2020-00207-IAPME)from the University of Macaothe Science and Technology Development Fund from Macao SAR(FDCT)(0125/2018/A3,0081/2019/AMJ,0033/2019/AMJ,0102/2019/A2,and 0154/2019/A3)+1 种基金the Nature Science Foundation of Shandong Province(ZR2020ZD04)Hunan Science Fund for Distinguished Young Scholars(2020JJ2046).
文摘碱性水电解(AWE)作为一种具有工业应用前景的绿色制氢方法,能够用来改善能源短缺和环境污染问题.然而,由于电极材料昂贵且效率低下,这种方法生产氢气的效率比较低.本文采用块状AlCoCrFeNi高熵合金作为碱性电解水的有效电极.研究发现通过快速阳极氧化(5 min)处理的高熵合金可以同时对析氢和析氧反应(HER和OER)具有超高的催化活性,只需要880和845 m V的过电位就可以达到-500 mA cm-2(HER)和500 mA cm-2(OER)的电流密度.特别地,该催化剂只需要3.00 V就可以达到500 mA cm-2的全解水电流密度,并且在此电流密度下表现出超过100小时的出色稳定性.我们的研究表明,阳极氧化的块体AlCoCrFeNi高熵合金作为高效催化剂在工业水电解制氢中具有广阔的应用前景,有望用于缓解环境问题和能源危机.
基金supported by the National Natural Science Foundation of China (Grant 11572249)the Aerospace Technology Foundation (Grant N2014KC0068)the Aeronautical Science Foundation of China (Grant N2014KC0073)
文摘In this work, analysis of electromigration-induced void morphological evolution in solder interconnects is performed based on mass diffusion theory. The analysis is conducted for three typical experimentally observed void shapes: circular, ellipse, and cardioid. Void morphological evolution is governed by the competition between the electric field and surface capillary force. In the developed model, both the electric field and capillary force on the void's surface are solved analytically. Based on the mass conversation principle, the normal velocity on the void surface during diffusion is obtained. The void morphological evolution behavior is investigated, and a physical model is developed to predict void collapse to a crack or to split into sub-voids under electric current. It is noted that when the electric current is being applied from the horizontal direction, a circular void may either move stably along the electric current direction or collapse to a finger shape, depending on the relative magnitude of the electric current and surface capillary force. However, the elliptical-shaped void will elongate along the electric current direction and finally collapse to the finger shape. On the other hand, the cardioid-shaped void could bifurcate into two sub-voids when the electric current reaches a critical value. The theoretical predictions agree well with the experimental observations.
文摘The magneto-impedance(MI) effect in amorphous and current annealed Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 wires has been measured to investigate the influence of DC annealing,highcurrent-density electropulsing annealing and tensile stress applied during annealing process.The results showed that the MI of DC annealed sample exhibits a sharp maximum.The Maximum MI ratio of 60%was observed in the sample of high-current-density electropulsing annealed under applied tensile stress.
