We demonstrate the feasibility of using a carbon nanotube to nanopump molecules.Molecular dynamics simulations show that the transport and ejection of a C20 molecule via a single-walled carbon nanotube(SWNT)can be achieved by a sustained mechanical actuation driven by two oscillating tips.The optimal condition for nanopumping is found when the tip oscillation frequency and magnitude correlate to form quasi steady-state mechanical wave propagation in the SWNT,so that the energy transfer process is optimal leading to maximal molecular translational motion and minimal rotational motion.Our finding provides a potentially useful mechanism for using an SWNT as a vehicle to deliver large drug molecules.
The research on lead-free piezoelectric ceramics has been one of the importantfields worldwide for years for the sustainable development of the world.In recent years,the author and his group concentrated their work on perovskite lead-free piezoelectric ceramics,especially on(Bi_(1/2)Na_(1/2))TiO_(3)(BNT)-and K_(1/2)Na_(1/2)NbO_(3)(KNN)-based ceramics.In this paper,the researches of the composition design on BNT-and KNN-based lead-free piezoelectric ceramics,the effects of doping on the properties of these ceramics,the study of the temperature stability of these ceramics,and the fabrication technique used in the author's group for these ceramics are reviewed,and the further considerations and some prospects to be resolved in coming years from the viewpoint of the device applications of these ceramics are suggested.
