Phase-change metasurfaces for dynamic image display and information encryption

Optical metasurfaces enable to engineer the electromagnetic space and control light propagation at an unprecedented level, offering a powerful tool to achieve modulation of light over multiple physical dimensions. Here, we demonstrate a Sb$_{2}$S$_{3}$ phase-change metasurface platform that allows active manipulation of both amplitude and phase. In particular, we implement dynamic nanoprinting and holographic image display through tuning crystallization levels of this phase-change material. The Sb$_{2}$S$_{3}$ nanobricks tailored to function the amplitude, geometric and propagation phase modulation constitute the dynamic meta-atoms in the multiplexed metasurfaces. Using the incident polarizations as decoding keys, the encoded information can be reproduced into a naonprinting grayscale image in the near field and two holographic images in the far field. These images can be switched on and off by taking advantages of the reversible tunability of Sb$_{2}$S$_{3}$ nanostructure between amorphous and crystalline states. The proposed phase-change metasurfaces featuring manifold information and multifold encryption promise ultracompact data storage with high capacity and high security, which suggests an exciting direction for modern cryptography and security applications

A review of university-enterprise-cooperation research in China: a quantitative perspective

The University-Enterprise-Cooperation (UEC) has been adopted by many universities globally to effectively utilize the high-quality resources of the construction industry, to improve the general competence, problem-solving skills and innovation capability of graduates of an engineering discipline. There are a limited amount of papers published in international journals on UEC, compared to a significant volume of Chinese published literature. However, based on the best knowledge of the authors, no existing literature has conducted a quantitative statistical analysis on UEC research in Chinese and international journals. In order to fill this knowledge gap, 300 high-quality papers on UEC were derived through the Chinese CNKI database from 2010-2019. The general development trend of UEC research in the past 30 years was also mapped and analyzed. The most popular topics under the UEC theme and the most frequently adopted research methods within the UEC field were also identified. It was found that since the first UEC publication in 1990, the number of UEC publications experienced a steady increase during the last decade, aiding by strong promotion from the government and active practice within universities and from educators in China. Course development (52.94%) and practice resource development (24.89%) were two of the most popular research topics in the UEC field. The elaboration research method was adopted by more than half (55.94%) of UEC papers, followed by case study (21.25%). The findings of this study are valuable for researchers and practitioners globally, to better understand the development status of UEC research in China and embark on future research in this field

STUDY ON THE INHIBITORY EFFECT OF DRYNARIA FORTUNEI EXTRACT ON HUMAN MYELOMA SP20 CELLS

The objective of the study was to investigate the inhibitory effect of Drynaria fortunei extract on human myeloma SP2 cells. Three different total extracts of Drynaria fortunei were obtained by reflux extraction method using different organic solvents including ethanol, methanol and petroleum ether. Their anticancer activities on SP20 cells were tested, and the maximum inhibition rate was obtained. The inhibitory effects on tumour cells at 12 h, 24 h, 36 h and 48 h were tested, and the inhibition curves at different time periods were plotted. The results showed that the methanol and ethanol extracts have similar inhibition rates at 24 h, which are around 55%. On the other hand, the maximum inhibition rate of petroleum ether extract is only 36% within 24h. Moreover, within the time periods of 36 h and 48 h, its inhibition rates are all below 10%