School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China.
Department of Engineering, Shenzhen MSU-BIT University, Shenzhen 518172, China.
Molecules. 2021 Aug 27;26(17):5199. doi: 10.3390/molecules26175199.
The molecular dynamics (MD) method is used to investigate the influence of the shielding gas on the dynamic behavior of the heterogeneous rotation transmission nano-system (RTS) built on carbon nanotubes (CNTs) and boron nitride nanotube (BNNT) in a helium environment. In the heterogeneous RTS, the inner CNT acts as a rotor, the middle BNNT serves as a motor, and the outer CNT functions as a stator. The rotor will be actuated to rotate by the motor due to the interlayer van der Waals effects and the end effects. The MD simulation results show that, when the gas density is lower than a critical range, a stable signal of the rotor will arise on the output and the rotation transmission ratio (RRT) of RTS can reach 1.0, but as the gas density is higher than the critical range, the output signal of the rotor cannot be stable due to the sharp drop of the RRT caused by the large friction between helium and the RTS. The greater the motor input signal of RTS, the lower the critical working helium density range. The results also show that the system temperature and gas density are the two main factors affecting the RTS transmission behavior regardless of the size of the simulation box. Our MD results clearly indicate that in the working temperature range of the RTS from 100 K to 600 K, the higher the temperature and the lower the motor input rotation frequency, the higher the critical working helium density range allows.
运用分子动力学（MD）方法，研究了氦气环境中屏蔽气体对构建在碳纳米管（CNTs）和氮化硼纳米管（BNNT）上的异质旋转传输纳米系统（RTS）动态行为的影响。在异质 RTS 中，内 CNT 充当转子，中间 BNNT 充当马达，外 CNT 充当定子。由于层间范德华力和端效应，转子将被马达驱动旋转。MD 模拟结果表明，当气体密度低于一定范围时，RTS 的输出端将出现稳定的转子信号，RTS 的旋转传输比（RRT）可达 1.0，但当气体密度高于一定范围时，由于氦气与 RTS 之间的剧烈摩擦导致 RRT 急剧下降，转子的输出信号将无法稳定。RTS 的马达输入信号越大，临界工作氦气密度范围越低。结果还表明，无论模拟盒的大小如何，系统温度和气体密度是影响 RTS 传输行为的两个主要因素。我们的 MD 结果清楚地表明，在 RTS 的工作温度范围为 100 K 至 600 K 时，温度越高，马达输入旋转频率越低，允许的临界工作氦气密度范围越高。
