Room-temperature phosphorescence (RTP) materials are normally prepared by doping guest materials into space-limited host materials to inhibit nonradiative decay. This work aims to prepare a long afterglow excitation-dependent emission RTP material by doping a small amount of 4-carboxyphenylboronic acid into the boric acid matrix, followed by heat-treating. The calculation of density functional theory shows that the electron cloud distribution and electron transfer trend of the selected material reduces the energy requirement to excite the RTP properties of the obtained materials. The obtained RTP materials can be excited by UV light at 310 and 365 nm for dark blue and green phosphorescence emission, respectively. The results demonstrate the long phosphorescence lifetimes of 1.97 and 0.62 s and the high absolute photoluminescence quantum yields of 17.4% and 15.6%. These results show that the obtained RTP materials have potential prospects as information coding and phosphorescent anti-counterfeiting.

A new highly uorescent hybrid material (CD@Eu-MOF) was synthesized by encapsulating CD (Carbon Dots) prepared from citric acid and ethylenediamine on the basis of a metal-organic framework prepared from Eu 3+ and 1,2,4-benzenetricarboxylic acid. The prepared composite not only maintains the excellent uorescence properties of CD and Eu 3+ respectively, but also forms a dual-emission uorescence system, and the system has good stability in aqueous solution. It was further used as a novel uorescent probe for the detection of Fe 3+ , which can effectively exclude the interference of other metal ions from the detection, and the intensity ratio of I Eu /I CD of CD@Eu-MOF material has a good linear relationship with Fe 3+ in the range of 1-200 μM. In this study, computer vision and BP (Back Propagation) neural network were used to train and t the sample data, and it was veri ed that the actual uorescence color of CD has a good linear relationship with Fe 3+ concentration. In addition, the BP neural network also veri ed that the uorescence spectrum data of CD@Eu-MOF also has a good linear relationship with Fe 3+ concentration.This study provides a new method for the fabrication of ratio and colorimetric Fe 3+ uorescence sensors, and provides a feasible solution for the simple and visual detection of Fe 3+ in the environment.

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compared with the traditional ACIDC traction load, the AC-DC AC traction load has its unique feature. The power electronic device brought by it certainly will have an effect on the power quality of the grid. The principle and modeling of the typical AC-DC-AC electric locomotive -CRH2 and its tractive power supply system is studied in this paper. The utility model of CRH2 and the Guilin power network is built based on the PSCAD/EMTDC which is a kind of the electromagnetic transient simulation software. The regional power grid is built, and the influence on the power quality of the Guilin grid caused by CRH2 is analyzed and verified by simulation. Finally, the treatment scheme of the problem of the power quality is presented in this paper.

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