Electrospinning has been employed to fabricate uniform polyacrylonitrile and polyacrylonitrile copolymer nanofiber mats supporting metalloporphyrins (MTPP; M: Zn(II), Cu(II), Ni(II), Co(II), Fe(III) and Pd(II); TPP: meso‐tetraphenylporphyrin). The nanofiber mat‐supported metalloporphyrins are shown as efficient photocatalysts for the degradation of various azo‐dyes in aqueous solutions under visible light irradiation. The effect of transition metals on azo‐dye photodegradation has been examined. The nanofiber mat‐supported copper–porphyrin and iron–porphyrin complexes are among the most effective photocatalysts for azo‐dye degradation. Immobilization of the metalloporphyrins onto the nanofiber mats greatly facilitates the recovery and reuse of the expensive and toxic photocatalysts. Most interestingly, there are no significant degradations of the photocatalytic activities of the recycled photocatalysts. © 2012 Society of Chemical Industry

A novel polyacrylonitrile hybrid fiber mat supported solid acid catalyst was prepared by electrospinning, and its catalytic activities were carefully investigated through acetalization reactions. The results showed that this hybrid fiber mat exhibits high activity for the reactions, with average yields over 95%. Besides having catalytic activities similar to the solid acid, the heterogeneous solid acid/polyacrylonitrile mat can be reused in six runs without significant loss of catalytic activities. The large size of the hybrid fiber mat greatly facilitates recovery of the catalyst from the reaction mixture. The high and stable catalytic activities of the hybrid fiber mat hold great potential for green chemical processes and preparation of membrane reactors in the future.

No abstract

In order to alleviate the conflict at intersections in a networked environment between trams in a semi-exclusive right-of-way mode and social vehicles, the running characteristics of these trams and vehicles and their coupling characteristics with the intersection signal are analyzed. The positive and negative effects of the special priority signal on the intersection are considered, and a guidance optimization model that combines urban rails and roads is constructed. With the aim of creating an unplanned delay adjustment scenario for trams, an online collaborative optimization algorithm is proposed, which takes the energy consumption, passenger travel time and comfort of both trams and connected vehicles as optimization objectives in order to realize integrated adjustment of the running trajectories and signal timing, and the population is evolved by using an adaptive elitist genetic algorithm. The study is based on the actual traffic information and timing scheme of an intersection on the T1 line of the Sanya Tram. By comparing with conventional trajectories, the optimized trajectories reduce the total transit time by about 17.1%, the total energy consumption by about 34.7% and the passenger discomfort degree by about 27.8%. The contradiction of the right-of-way distribution at the intersection is alleviated, effectively safeguarding the interests of different users and enterprises. The experimental results show that the model has excellent applicability for different proportions of passenger numbers.

A novel polyacrylonitrile hybrid fiber mat‐supported solid acid catalyst is produced by electrospinning of polyacrylonitrile with a solid acid prepared from polyvinyl alcohol and hydroxyethylsulfonic acid.