Research on Phase Detection of Liquid Crystal Optical Device

The technology for phase detection of liquid crystal optical device is a difficult research in current domestic and overseas. However, for the existing liquid crystal optical device, aiming at the poor anti-vibration capability and poor versatile of phase detection, the complexity of phase retrieval algorithm, we propose a new phase measurement principle and experimental methods of liquid crystal optical device. It is a phase measurement method based on the combination of phase- shifting interferometer and phase conjugation technology. The deflection characteristics of the liquid crystal device means the device can implement phase modulation to only one direction of polarized light while is completely transparent to orthogonal polarized light. We put forward the phase shift of the orthogonal polarization phase shift interferometer method, using phase shifting interference as well as the combination of phase conjugate means to achieve its phase measurement. So we can retrieves devices modulation phase simply and efficiently combines with phase- shifting interferometer technology.

Self-healing polyamide reverse osmosis membranes with temperature-responsive intelligent nanocontainers for chlorine resistance

Improving the performance of reverse osmosis membranes remains great challenge to ensure excellent NaCl rejection while maintaining high water permeability and chlorine resistance. Herein, temperature-responsive intelligent nanocontainers are designed and constructed to improve water permeability and chlorine resistance of polyamide membranes. The nanocontainer is synthesized by layer-by-layer self-assembly with silver nanoparticles as the core, sodium alginate and chitosan as the repair materials, and polyvinyl alcohol as the shell. When the polyamide layer is damaged by chlorine attack, the polyvinyl alcohol shell layer dissolves under temperature stimulation of 37 ℃, releasing inner sodium alginate and chitosan to repair broken amide bonds. The polyvinyl alcohol shell responds to temperature in line with actual operating environment, which can effectively synchronize the chlorination of membranes with temperature response and release inner materials to achieve self-healing properties. With adding temperature-responsive intelligent nanocontainers, the NaCl rejection of thin film composite membrane decreased by 15.64%, while that of thin film nanocomposite membrane decreased by only 8.35% after 9 chlorination cycles. Effective repair treatment and outstanding chlorine resistance as well as satisfactory stability suggest that temperature-responsive intelligent nanocontainer has great potential as membrane-doping material for the targeted repair of polyamide reverse osmosis membranes.

N,P-codoped porous carbon derived from chitosan with hierarchical N-enriched structure and ultra-high specific surface Area toward high-performance supercapacitors

In this work,a facile"carbonization-activation"strategy is developed to synthesize N,P-codoped hierarchical porous carbon.Phosphoric acid is innovatively introduced during the hydrothermal process to achieve in-situ P doping as well as create abundant pores,and the employment of sodamide is of vital importance to simultaneously serve as activating agent and N-source to succeed a high-level N doping.Thus,the obtained samples exhibit a unique three-dimensional hierarchical structure with an ultra-high specific surface area(3646 m^(2)g^(-1))and ultra-high N-doping level(9.81 at.%).Computational analyses confirm that N,P co-doping and higher N content can enhance active sites and widen potential differences of carbon materials to improve their capacitance.The as-prepared carbon materials demonstrate superior electrochemical performances,such as an ultra-high capacitance of 586 Fg^(-1)at 1 Ag^(-1),a superior rate capability of 409 Fg^(-1)at 20 Ag^(-1),and excellent long-term stability of 97%capacitance retention after10,000 cycles in 6 M KOH.Moreover,an assembled symmetric supercapacitor delivers a high energy density of 28.1 Wh kg^(-1)at the power density of 450 W kg^(-1)in 1 M Na_(2)SO_(4),demonstrating a great potential for applications in supercapacitors.