The phase of confined water is ubiquitous in biology, materials science and nanotechnology. Recent studies showed that the spatial confinement influences the arrangement of water molecules and their dynamics. But the effect of confinement in a curved space has not been explored. In this study, we examine the effect of the curvature on the behaviors of confined water. We show that curved water monolayer, bilayer and triple layers can form within the inter-wall space of double-walled carbon nanotubes. We find that while the inter-wall distance affects the diffusion of water molecules along the axial direction of double-walled carbon nanotube, the curvature dominates the diffusion along the circumferential direction. We also find that the electric field helps to trap water molecules in the curved space. These results uncover the effect of curvature on the behaviors of confined water, and shed light on regulating the structure and dynamics of water at nanoscale.

Carbon nanotube complexes are known for their miraculous mechanical and electronic properties that are crucial for nano-electromechanical systems (MEMS). In this study, through molecular dynamics simulations we found for the first time that the electric field and temperature can be used to co-regulate a reversible change of cross-sectional configuration of single-wall carbon nanotubes (SWCNTs). We showed that the electric field can help induce the collapse of an SWCNT when it contains a water droplet, while the increase of temperature can quickly recover its configuration. This controllable bistability of SWCNTs is promising for the design of nanodevices such as electromechanical switches in NEMS.

A broadband microstrip patch antenna with multi-layer substrate for fuze application is designed. The multi-layer substrate is composed of the bottom layer of Si with low electric conductivity, the middle and the top layers of Si with high electric conductivity. An air cavity is fabricated by inductively coupled plasma (ICP) etching in the middle layer of Si to reduce the effective dielectric constant of the multi-layer substrate. The multi-layer substrate microstrip patch antenna is simulated and optimized by finite element method. The simulation results show that operating at 10GHz, the bandwidth and the gain of the multi-layer substrate microstrip patch antenna are 15.5% and 6.1dB respectively, which meet the needs of the application in fuze well.

An effective non-contact electrostatic detection method is used for human body motion detection. Theoretical analysis and pratical experiments are carried out to prove that this method is effective in the field of human body monitoring, in which a model for human body induced potential by stepping has been proposed. Furthermore, experiment results also prove that it’s feasible to measure the average velocity and route of human body motion by multiple electrodes array. What’s more the real-time velocity and direction of human body motion can be determined by orthogonal electrostatic detector array, and the real-time velocity and direction of human body motion can be obtained within the range of 2 meters.

The flow distribution in flue pipes has a great effect on collection efficiency.Gas pressure and velocity distribution in flue pipes upstream electrostatic precipitator were investigated using computational fluid dynamics (CFD) in this paper. The flue pipe model was established on the basis of standard straight and bended flue pipe which were widely used in engineering. And the availability of numerical simulation model was verified by comparing the empirical curve and the numerical simulation results of a common pipe bend without inner supports. In the same condition, these two flue pipes were simulated. The result shows that inner supports have great impact on flue pipe and the values of the pressure drops are closely linked to airflow directions. These results can provide theoretical basis and method guidance for design of inner support.