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Meso-tetraphenylporphyrinatooxidovanadium(IV) [V^IVO(TPP)] (1) and 2,3,7,8,12,13, 17,18-octabromo-meso-tetraphenylporphyrinatooxidovanadium(IV) [V^IVO(TPPBr${}_8)$] (2) were synthesized and characterized by various spectroscopic techniques. 1 and 2 were utilized as efficient catalysts for the selective epoxidation of olefins. Catalyst 2 shows very high catalytic activity (TOF = 8783–13108 h${}^{-1})$ as compared to 1 (TOF = 2175–3296 h${}^{-1})$. The catalysts are recyclable, as their recyclability was checked for four cycles and show only minor reduction of their efficiency.

Studying the transport characteristics of carriers in quantum dot (QD) film provides theory support for the structure design and performance improvement of QD film device. However, time of flight experiment can only test the global optoelectric current signal brought by the carrier transport, and cannot analyze the carrier transport in the transport layer. Here, the hopping transport model of photogenerated carriers in QD films was established to study the expansion and drift movement of carriers in the PDE module of COMSOL. According to the material properties of the actual QD films, the carrier transport in single-size QD films was studied.

The Beijing spectrometer III (BESIII) is a high precision detector located at the Beijing electron positron collider II (BEPCII). After running ten years, the BESIII sub-systems are suffering from the aging problems that lead to a performance degradation. In order to ensure the study of the important physics topics in tau-charm energy region that can be further explored at the BESIII, the BESIII experiment has received several upgrades. We report the upgrades of the BESIII, including the inner part of the drift chamber, the end cap of the time-of-flight system and the valve box of the superconducting magnet.