The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging ...The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging bio-inspired strategies for the development of flexible and stretchable electronics that can accommodate mechanical deformations and integrate seamlessly with biological systems.We will provide an overview of the practical considerations in the materials and structure designs of flexible and stretchable electronics.Recent progress in bio-inspired pressure/strain sensors,stretchable electrodes,mesh electronics,and flexible energy devices are then discussed,with an emphasis on their unconventional micro/nanostructure designs and advanced functionalities.Finally,current challenges and future perspectives are identified and discussed.展开更多
Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is ...Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is important, such as in the aerospace and automotive industries.However, their practical applications are still limited because of their poor corrosion resistance, low high temperature strength and ambient formability. Based on such their property shortcomings, recently degradable magnesium alloys were developed for broadening their potential applications. Considering the degradable Mg alloys for medical applications were well reviewed, the present review put an emphasis on such degradable magnesium alloys for structural and functional applications, especially the applications in the environmental and energy fields. Their applications as fracture ball in fossil energy, sacrificial anode, washing ball, and as battery anodes, transient electronics, were summarized. The roles of alloying elements in magnesium and the design concept of such degradable magnesium alloys were discussed. The existing challenges for extending their future applications are explored.展开更多
To accurately predict the fatigue life of a power device, a fatigue life evaluation method that is based on the power cycle is presented in terms of an algorithm based on a combination of electrical analysis, heat ana...To accurately predict the fatigue life of a power device, a fatigue life evaluation method that is based on the power cycle is presented in terms of an algorithm based on a combination of electrical analysis, heat analysis, and stress analysis. In literature, the fatigue life of power devices has been evaluated on the basis of the thermal cycle. This cycle is alternately repeated within a range from a high temperature to a low temperature. In an actual operating environment, however, a power device works in a power cycle that consists of being switched ON and OFF. To accurately predict the fatigue life cycle of a device, then, the evaluation should take account of this important aspect of the power cycle. To verify the utility of the evaluation method presented in this study, the results for a power cycle based on the combined use of electrical analysis, heat analysis, and stress analysis are compared to the results based on the thermal cycle, as found in the literature. Our conclusion is that the fatigue life cycle as estimated by the thermal cycle test is higher than that estimated by the power cycle.展开更多
文摘为钻机混合动力传动系统研制了1套1 MW/60 MJ飞轮储能系统,开展了轴系动平衡、充放电、损耗和效率测试实验研究。采用高强度合金钢变截面飞轮存储动能,飞轮电机轴系为立式支撑结构,重型拼装永磁环轴承承担了97%的轴系重量。永磁电机转子采用格柵结构硅钢内嵌磁钢,以实现较高速度安全运转。基于大容量功率电子变换和电机控制技术,开发了100~300 k W充电、500~1 000 k W放电的控制电路硬件和软件,充电过程中采用了弱磁、转速和电流的双闭环控制策略,放电过程中采用电压闭环和电流前馈控制策略。动平衡后飞轮储能机组振动减少为0.07 mm以内。飞轮储能电源充放电循环效率达到86%~88%。
基金We thank Dr.Jidong Shi from The Hong Kong Polytechnic University for helpful discussions.This work is supported by the National Natural Science Foundation of China(Nos.21790393 and 51972073)Frontier Research Program of the Chinese Academy of Sciences(No.XDB32030100).
文摘The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging bio-inspired strategies for the development of flexible and stretchable electronics that can accommodate mechanical deformations and integrate seamlessly with biological systems.We will provide an overview of the practical considerations in the materials and structure designs of flexible and stretchable electronics.Recent progress in bio-inspired pressure/strain sensors,stretchable electrodes,mesh electronics,and flexible energy devices are then discussed,with an emphasis on their unconventional micro/nanostructure designs and advanced functionalities.Finally,current challenges and future perspectives are identified and discussed.
文摘Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is important, such as in the aerospace and automotive industries.However, their practical applications are still limited because of their poor corrosion resistance, low high temperature strength and ambient formability. Based on such their property shortcomings, recently degradable magnesium alloys were developed for broadening their potential applications. Considering the degradable Mg alloys for medical applications were well reviewed, the present review put an emphasis on such degradable magnesium alloys for structural and functional applications, especially the applications in the environmental and energy fields. Their applications as fracture ball in fossil energy, sacrificial anode, washing ball, and as battery anodes, transient electronics, were summarized. The roles of alloying elements in magnesium and the design concept of such degradable magnesium alloys were discussed. The existing challenges for extending their future applications are explored.
文摘To accurately predict the fatigue life of a power device, a fatigue life evaluation method that is based on the power cycle is presented in terms of an algorithm based on a combination of electrical analysis, heat analysis, and stress analysis. In literature, the fatigue life of power devices has been evaluated on the basis of the thermal cycle. This cycle is alternately repeated within a range from a high temperature to a low temperature. In an actual operating environment, however, a power device works in a power cycle that consists of being switched ON and OFF. To accurately predict the fatigue life cycle of a device, then, the evaluation should take account of this important aspect of the power cycle. To verify the utility of the evaluation method presented in this study, the results for a power cycle based on the combined use of electrical analysis, heat analysis, and stress analysis are compared to the results based on the thermal cycle, as found in the literature. Our conclusion is that the fatigue life cycle as estimated by the thermal cycle test is higher than that estimated by the power cycle.
