133Ba, 63Ni, and 60Co are hazardous to the ecosystem and human health. Their nonradioactive isotopes are also worthy of concern as toxic metal ions. Barium can be studied as a simulant of hazardous 226Ra because of their comparable ionic radii and similar ion exchange behaviors. Herein, we report that the layered metal sulfide (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS) exhibits excellent capture properties for Ba2+, Ni2+, and Co2+ with high capacities (q m Ba = 289.0 mg/g; q m Ni = 83.27 mg/g; and q m Co = 51.98 mg/g), fast kinetics (within 5 min), wide pH durability, and outstanding Ba2+ selectivity. FJSM-SnS exhibits high removal efficiencies (>99%) for these ions in ion-exchange column experiments. The material possesses radiation resistance with good structural and crystal stability; it survives highly acidic conditions. Our results point to a promising scavenger for Ba2+, Ni2+, and Co2+ and, by extension, the even more harmful 226Ra, which suggest that metal sulfide materials should be considered as effective scavengers for these ions from complex wastewater.

By combining the modified nearest neighbor approach and the improved inver-over operation, an Artificial Bee Colony (ABC) Algorithm for Traveling Salesman Problem (TSP) is proposed in this paper. The heuristic approach was tested in some benchmark instances selected from TSPLIB. In addition, a comparison study between the proposed algorithm and the Bee Colony Optimization (BCO) model is presented. Experimental results show that the presented algorithm outperforms the BCO method and can efficiently tackle the small and medium scale TSP instances.

A thorough OFDM parameter design method of a digital broadcasting system in FM band is presented in this paper. Key OFDM parameters are analyzed from their constraints. Cyclic prefix should satisfy the requirement of channel delay and formation of SFN. Design of system bandwidth should consider coherent bandwidth and existing frequency planning. Symbol duration is restricted by time selectivity and frequency selectivity of the channel, and also efficient SINR should be maximized. System simulation is performed to test and verify the parameters under typical FM band channels. A set of OFDM parameter is provided for future design.