Abstract-High extinction ratio terahertz broadband polarizer based on the aligned Ni nanowire arrays

Wenfeng Xiang, Xiaowei Huang, Dong Li, Qingli Zhou, Haizhong Guo, and Junjian Li

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-45-7-1978

We present a broadband terahertz (THz) polarizer based on the stacks of aligned Ni nanowire (NW) arrays. We demonstrated that the polarizer has an extinction ratio of 58.8 dB and an average extinction ratio of 46.6 dB throughout a frequency range of 0.3–2.3 THz. Compared to carbon-nanotube and metallic wire-grid polarizers, our Ni-NW polarizers with rapid, reliable, low-cost fabrication processes are ideal candidates for emerging THz technologies.

© 2020 Optical Society of America

Abstract- Design and experiment of A 340 GHz traveling wave tube for terahertz cloud radars

Pan Pan,  Ye Tang,  Hanyan Li,  Tianyi Li,  Lin Zhang,  Dong Li,   Jinjun Feng,

https://ieeexplore.ieee.org/document/8289713/


The 340 GHz traveling wave tube is being developed for the terahertz cloud radar. The device is designed to produce 1 W output power. It uses a pencil electron beam focused by PPM and a microfabricated folded waveguide slow wave structure. The first prototype has achieved 50 mA of transmission current but there is no amplification due to the immense loss. After redesign and improvement of the slow wave structure, the loss of the latest prototype is much lower. The latest prototype will be tested soon.

Abstract-Crystal engineering approach to produce complex of azelnidipine with maleic acid

Weiguang Lian , Dong Li , Min Wang , Caiqin Yang and Jing Wang                                            
http://pubs.rsc.org/en/content/articlelanding/2013/CE/C3CE26967A

A novel azelnidipine-maleic acid complex was prepared by the solvent-assisted cogrinding method. The obtained complex was characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), infrared (IR), Raman, solid-state nuclear magnetic resonance (ssNMR), and terahertz (THz) spectroscopy. The PXRD and DSC measurement identified new different crystal form of the obtained complex other than those of the single azelnidipine and maleic acid. It was revealed that the azelnidipine-maleic acid complex was formed at a molar ratio of 2:1. IR, Raman and ssNMR spectroscopy verified that C-H...O hydrogen bond was formed between C=O from maleic acid and methyl group from azelnidipine. The distinctive THz spectrum showed that the vibrational mode of the complex was different from those of the starting materials, suggesting that THz spectroscopy is an ideal tool to evaluate complex formation. The solubilities of azelnidipine in maleic acid with different concentrations at different temperatures were investigated; the obtained values were used to calculate the formation constants and thermodynamic parameters. The improved dissolution rate in vitro of the complex showed potential to improve the physicochemical properties of azelnidipine API by crystal engineering approach