Soft actuators endowed with self-sensing capability become highly sought after in recent years.Ti3C2Tx MXene is expected to be used in the development of self-sensing actuators due to its outstanding physical and chem...Soft actuators endowed with self-sensing capability become highly sought after in recent years.Ti3C2Tx MXene is expected to be used in the development of self-sensing actuators due to its outstanding physical and chemical properties.However,achieving precise deformation feedback of MXene-based actuators remains a challenge,as the resistance change of MXene is not only affected by deformation,but also by temperature,and the decoupling is difficult.Here,a composite ink with temperature self-compensation(0.00125%·°C^(−1) of temperature coefficient of resistance)is fabricated by combining MXene and graphite with opposite temperature coefficients of resistance.The composite ink can be written on a variety of substrates,including glass,cellulose paper,and various polymers.Based on this,an ink-cellulose/polymer composite actuator with self-sensing function is actualized.The actuator can achieve accurate real-time deformation feedback by monitoring the resistance signal of ink-cellulose layer,which shows a high linear sensitivity(gauge factor~14.5,coefficient of determination(R^(2))>0.99),thereby realizing the perception of touch behavior and distinguishing objects with different weights,softness,and roughness.Besides,a series of biomimetic devices and soft robots with programmable movements(rolling and self-sustained oscillating)are also demonstrated.The results offer new insights for the development of the self-sensing actuators.展开更多
1000 MPa级高强钢在水电领域的应用已日趋成熟,但国内相应高性能焊材的研发较少,高强度熔敷金属保持低温高韧性是研发难点之一.通过添加Ce元素优化熔敷金属,并利用扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(tr...1000 MPa级高强钢在水电领域的应用已日趋成熟,但国内相应高性能焊材的研发较少,高强度熔敷金属保持低温高韧性是研发难点之一.通过添加Ce元素优化熔敷金属,并利用扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)、高温激光共聚焦扫描显微镜(confocal laser scanning microscope,CLSM)等微观组织表征方法,研究了Ce含量对1000 MPa级高强钢埋弧焊熔敷金属组织强韧性及组织演变规律的影响.结果表明,Ce含量为0.02%时,抗拉和屈服强度分别提高3.7%和17.2%,此时强韧匹配效果最好,低温冲击韧性整体提升,Ce含量为0.01%时提升最大,-40℃和-60℃环境下分别为24.3%和42.2%.微观组织方面,Ce可细化晶粒,使M-A组元分布更弥散,增强组织韧性;含量为0.04%时会使块状铁素体和针状铁素体尺寸变大、大尺寸晶粒增多,影响抗拉强度.演变机理上,Ce与C协同富集引发晶格畸变促进M-A组元生成,含量为0.02%时使残余奥氏体含量增加,借助相变诱发塑性(transformationinduced plasticity,TRIP)效应提升塑性变形能力,促进下贝氏体转变实现强韧性协同提升;0.04%的Ce则导致晶界偏析加剧,形成含Ce脆性相析出物,降低奥氏体稳定性,使冲击韧性相对于0.02%时劣化.展开更多
For a birth and death processX=|X(t),t <σ| with explosion and lifespanu distributions and joint distributions of first hitting time and first hitting location after explosion of setB n = |0,1,...,n| ,n have been f...For a birth and death processX=|X(t),t <σ| with explosion and lifespanu distributions and joint distributions of first hitting time and first hitting location after explosion of setB n = |0,1,...,n| ,n have been found.展开更多
激光诱导石墨烯由于其制备便捷,物理化学特性可调节,兼容性强等特点,已被广泛应用于微电子、储能器件和柔性可穿戴设备等领域,获取高质量的激光诱导石墨烯是进一步推广其应用的重要前提。本文重点关注激光诱导石墨烯碳化过程,基于Reax F...激光诱导石墨烯由于其制备便捷,物理化学特性可调节,兼容性强等特点,已被广泛应用于微电子、储能器件和柔性可穿戴设备等领域,获取高质量的激光诱导石墨烯是进一步推广其应用的重要前提。本文重点关注激光诱导石墨烯碳化过程,基于Reax FF反应力场搭建分子动力学模型,通过调整聚酰亚胺热解的控制参数对碳化过程进行了分析,结合分子构型演变和结晶特性分析研究了石墨烯簇的生长机制。仿真结果表明:提高反应温度或延长反应时间有助于增加产物中六元环的数量。基于仿真结论,应用较高的激光功率,降低扫描速度,制备LIG超级电容器,获得了良好的倍率性能(500 m V·s^(-1)扫描速率下保持初始容量的70%)和较低的等效串联电阻(52Ω)。展开更多
Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT ad...Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT addition(0.2 wt%)was found for significantly improving delithiation capacity,first cycle coulombic efficiency(FCE),and capacity retention.Particularly,Si(10 wt%)-graphite electrode exhibits 560 mAh/g delithiation capacity and 92%FCE at 0.2 C during the first chargedischarge cycle,and 91%capacity retention after 50 cycles(0.5 C)in a half cell.Scanning electron microscope(SEM)was used to illustrate the electrode morphology,compositions and promoting function of the SWCNT additives.In addition,full cells assembled with high nickel-NCM811 cathodes and fim-Si-graphite composite anodes were evaluated for the consistence between half and full cell performance,and the consideration for potential commercial application.Finally,criteria to assess Si-containing anodes are proposed and discussed from an industrial perspective.展开更多
基金supported by the National Key R&D Program of China(NO.2024YFB3409900)the China Postdoctoral Science Foundation(No.2023M730845)the Heilongjiang Postdoctoral Fund(No.LBH-Z23182).
文摘Soft actuators endowed with self-sensing capability become highly sought after in recent years.Ti3C2Tx MXene is expected to be used in the development of self-sensing actuators due to its outstanding physical and chemical properties.However,achieving precise deformation feedback of MXene-based actuators remains a challenge,as the resistance change of MXene is not only affected by deformation,but also by temperature,and the decoupling is difficult.Here,a composite ink with temperature self-compensation(0.00125%·°C^(−1) of temperature coefficient of resistance)is fabricated by combining MXene and graphite with opposite temperature coefficients of resistance.The composite ink can be written on a variety of substrates,including glass,cellulose paper,and various polymers.Based on this,an ink-cellulose/polymer composite actuator with self-sensing function is actualized.The actuator can achieve accurate real-time deformation feedback by monitoring the resistance signal of ink-cellulose layer,which shows a high linear sensitivity(gauge factor~14.5,coefficient of determination(R^(2))>0.99),thereby realizing the perception of touch behavior and distinguishing objects with different weights,softness,and roughness.Besides,a series of biomimetic devices and soft robots with programmable movements(rolling and self-sustained oscillating)are also demonstrated.The results offer new insights for the development of the self-sensing actuators.
文摘For a birth and death processX=|X(t),t <σ| with explosion and lifespanu distributions and joint distributions of first hitting time and first hitting location after explosion of setB n = |0,1,...,n| ,n have been found.
文摘激光诱导石墨烯由于其制备便捷,物理化学特性可调节,兼容性强等特点,已被广泛应用于微电子、储能器件和柔性可穿戴设备等领域,获取高质量的激光诱导石墨烯是进一步推广其应用的重要前提。本文重点关注激光诱导石墨烯碳化过程,基于Reax FF反应力场搭建分子动力学模型,通过调整聚酰亚胺热解的控制参数对碳化过程进行了分析,结合分子构型演变和结晶特性分析研究了石墨烯簇的生长机制。仿真结果表明:提高反应温度或延长反应时间有助于增加产物中六元环的数量。基于仿真结论,应用较高的激光功率,降低扫描速度,制备LIG超级电容器,获得了良好的倍率性能(500 m V·s^(-1)扫描速率下保持初始容量的70%)和较低的等效串联电阻(52Ω)。
文摘Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT addition(0.2 wt%)was found for significantly improving delithiation capacity,first cycle coulombic efficiency(FCE),and capacity retention.Particularly,Si(10 wt%)-graphite electrode exhibits 560 mAh/g delithiation capacity and 92%FCE at 0.2 C during the first chargedischarge cycle,and 91%capacity retention after 50 cycles(0.5 C)in a half cell.Scanning electron microscope(SEM)was used to illustrate the electrode morphology,compositions and promoting function of the SWCNT additives.In addition,full cells assembled with high nickel-NCM811 cathodes and fim-Si-graphite composite anodes were evaluated for the consistence between half and full cell performance,and the consideration for potential commercial application.Finally,criteria to assess Si-containing anodes are proposed and discussed from an industrial perspective.
