Electronic Structure and Physical Characteristics of Dioxin Under External Electric Field

Dioxin is a highly toxic and caustic substance,which widely existed in the atmosphere,soil and water with tiny particles.Dioxin pollution has become a major problem that concerns the survival of mankind,which must be strictly controlled.The bond length,bond angle,energy,dipole moment,orbital energy level distribution of dioxin under the external field are investigated using DFT(density functional theory)on basis set level of B3LYP/6-31G(d,p).The results indicate that with the increase of the electric field,the length of one Carbon-Oxygen bond increases while another Carbon-Oxygen bond decreases.The energy gradually decreases with the electric field,while the change of the dipole moment has an opposite trend.In the infrared spectra,the vibration frequency decreases with the electric field increasing and shows an obvious red shift.Moreover,the ultraviolet-visible absorption spectra under different electric fields are analyzed with TD-DFT(time-dependent density functional theory)method.The wavelength of the strongest absorption peak increases and occurs red shift with the increase of the electric field.All the above results can provide reference for further research on the properties of dioxin under different external electric field.

Foveated glasses-free 3D display with ultrawide field of view via a large-scale 2D-metagrating complex

Glasses-free three-dimensional(3D)displays are one of the game-changing technologies that will redefine the display industry in portable electronic devices.However,because of the limited resolution in state-of-the-art display panels,current 3D displays suffer from a critical trade-off among the spatial resolution,angular resolution,and viewing angle.Inspired by the so-called spatially variant resolution imaging found in vertebrate eyes,we propose 3D display with spatially variant information density.Stereoscopic experiences with smooth motion parallax are maintained at the central view,while the viewing angle is enlarged at the periphery view.It is enabled by a large-scale 2D-metagrating complex to manipulate dot/linear/rectangular hybrid shaped views.Furthermore,a video rate full-color 3D display with an unprecedented 160°horizontal viewing angle is demonstrated.With thin and light form factors,the proposed 3D system can be integrated with off-the-shelf purchased flat panels,making it promising for applications in portable electronics.