Modulation Of The Kinetic Properties Of Water In Nanochannel By Terahertz Electric Fields

Selective Laser Melting(SLM)is a rapid prototyping technology based on laser and powder bed,which can be used to manufacture metal parts with complex structure and excellent performance.Al-Mg-Sc aluminum alloys have good comprehensive mechanical properties and corrosion resistance,and have broad application prospects in aerospace and other fields.At the same time,light and complex metal parts with excellent performance can be obtained by combining selective laser melting technology and Al-Mg-Sc aluminum alloy.In this paper,the selective laser melting Al-Mg-Sc alloy is taken as the research object,and the influence of process parameters such as scanning speed and layer thickness on the microstructure and mechanical properties of the alloy is studied;By comparing the printed and cast alloy samples,the heat treatment effect of process on the microstructure and mechanical properties of Al-Mg-Sc alloy,and explore its heat treatment strengthening mechanism.The main research contents are as follows:Nanoscience and technology is a kind of science and technology that uses atoms and molecules for material fabrication.The study of physics at the nanoscale is an important branch of nanoscience,and the progress of the study of physics at the nanoscale can help us solve some important problems in human society.Water is the source of life,and the study of the structure and kinetic properties of water molecules at the nanoscale is very important for biological metabolic processes to explore bionanism,desalination of seawater and some key problems in physics and chemistry.Understanding the transport behavior of water in different structured nanochannels can help people to gain insight into the transport properties and kinetic laws of water in the confined space,and provide a basis for the development of nano transport devices in a physical sense.The simple structure of carbon nanotubes,similar to biological pores,has been widely used in various research fields,including computer simulation studies of nanotubes.Controlling the transport of water within carbon nanotubes is important because changing the shape of the nanotubes or interacting with water can lead to a change in the state of the nanotubes.Water in nanotubes can exhibit unique structural and kinetic properties that are different from those of bulk water,but existing experimental techniques and studies are still ineffective in detecting and characterizing it.In this paper,we first investigate the structural properties of confined water in(6,6)carbon tubes using infrared absorption spectroscopy,and find that the main peaks of SW in the 0-35 THz region are significantly blueshifted and enhanced with respect to bulk water.It is suggested that the change in the weight of the libration(including rock,twist,and wag modes)coupling is caused by the change in the weight of the higher frequency twist and wag modes in SW.At the same time,it is shown that the SW spectral component properties can well predict and explain the structural and dynamical properties of SW,and the infrared absorption of SW has been verified by terahertz electric field simulations to be consistent with the spectral distribution properties.Secondly,we found that 14 THz is the most sensitive band of confined water in(6,6)carbon tubes for terahertz electric field by applying 0-30 terahertz electric field to the system model and using the average hydrogen bonding number,average kinetic energy and other kinetic parameters of the confined water molecules in carbon tubes.Moreover,14THz-16 THz is the most sensitive band for the confined water in(6,6)-(10,10)SWNT,and the motion of the confined water in this band is verified by the theoretical model,and the results are more consistent with the experimental results.Overall,it seems to be possible to modulate the kinetic properties of the confined water molecules by controlling the frequency of the applied terahertz electric field.By studying the transport behavior of water molecules in carbon nanotubes through molecular dynamics simulations,we can gain insight into the transport properties and kinetics of water in confined spaces,and provide theoretical basis and technical support for the development of related applications.At the same time,this discovery is not only one of the hot issues in many scientific fields,but also important for the investigation of the working mechanism of nanotransport devices and biological channels.