Capital Normal University

About: Capital Normal University is a education organization based out in Beijing, China. It is known for research contribution in the topics: Terahertz radiation & Quantum entanglement. The organization has 11441 authors who have published 11988 publications receiving 159071 citations. The organization is also known as: Shǒudū Shīfàn Dàxué.

Room-Temperature Phosphorescence in Pure Organic Materials: Halogen Bonding Switching Effects.

Abstract: Organic room-temperature phosphorescence (ORTP), when combined with external stimuli-responsive capability, is very attractive for sensors and bio-imaging devices, but remains challenging. Herein, by doping two β-iminoenamine-BF2 derivatives (S-2CN and S-2I) into a 4-iodoaniline (I-Ph-NH2 ) crystalline matrix, the formation of S-2CN⋅⋅⋅I-Ph-NH2 and S-2I⋅⋅⋅I-Ph-NH2 halogen bonds leads to bright-red RTP emissions from these two host-guest doped crystals (hgDCs) with quantum efficiencies up to 13.43 % and 15.96 %, respectively. Upon treatment with HCl, the competition of I-Ph-NH2 ⋅HCl formation against S-2I⋅⋅⋅I-Ph-NH2 halogen bonding switches off the red RTP from S-2I/I-Ph-NH2 hgDCs, whereas the stable halogen-bonded S-2CN⋅⋅⋅I-Ph-NH2 ensures red RTP from S-2CN/I-Ph-NH2 hgDCs remains unchanged. A security protection luminescence pattern by using these different HCl-responsive RTP behaviors was designed.

What Is History

Abstract: History has three meanings: the developing process of mankind, recordings of past things and people's understanding of history. Historical theory is different from the theory of historical science. The former discusses what objective history is, namely, understanding of historical contents. The latter discusses historical science, generalizes the theory and way that people understand history, namely, how to understand and expound history correctly.

Terahertz vortex beam generator based on a photopatterned large birefringence liquid crystal.

Abstract: A terahertz (THz) q-plate is proposed and demonstrated to generate THz vortex beams. It is composed of a large birefringence liquid crystal (LC) with spatially-varying director distribution sandwiched by two pieces of fused silica glass. A polarization-sensitive alignment agent is photopatterned to carry out the specific LC director distribution. THz vortex beams with different topological charges are characterized with a THz digital holographic imaging system. The intensity and phase distributions consistent with theoretical analyses are obtained. Besides, an eight-lobed intensity distribution is observed corresponding to the vertical polarization component of a cylindrical vector beam. This work may inspire novel THz applications.

Progresses on microwave remote sensing of land surface parameters

Abstract: Highly accurate observations at various scales on the land surface are urgently needed for the studies of many areas, such as hydrology, meteorology, and agriculture. With the rapid development of remote sensing techniques, remote sensing has had the capacity of monitoring many factors of the Earth’s land surface. Especially, the space-borne microwave remote sensing systems have been widely used in the quantitative monitoring of global snow, soil moisture, and vegetation parameters with their all-weather, all-time observation capabilities and their sensitivities to the characteristics of land surface factors. Based on the electromagnetic theories and microwave radiative transfer equations, researchers have achieved great successes in the microwave remote sensing studies for different sensors in recent years. This article has systematically reviewed the progresses on five research areas including microwave theoretical modeling, microwave inversion on soil moisture, snow, vegetation and land surface temperatures. Through the further enrichment of remote sensing datasets and the development of remote sensing theories and inversion techniques, remote sensing including microwave remote sensing will play a more important role in the studies and applications of the Earth systems.