We herein present a tabu search algorithm with variable cluster grouping (TSVCG for short) to deal with Multidepot vehicle routing problem (MDVRP for short). In TSVCG, we firstly adopt variable cluster grouping to convert a complicated MDVRP to typical single depot vehicle routing problem (SDVRP for short). And then we apply a tabu search algorithm to solve each SDVRP. In the grouping process, we discuss how to find a scale factor and minimum geometric semicircle correction factor to improve the customer points' grouping, and thus get the different groups for further problemsolving. The experimental results shown that the proposed variable cluster grouping can reduce grouping blindness and improve the efficiency of grouping and viability of group results. The results also shown that the proposed TSVCG performed well compared with the previous work with the geometric grouping.

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Differential scanning calorimetry (DSC) was used to determine the crystallization fraction and rate in TiNi alloys by severe plastic deformation. Results showed that the reverse martensitic transformation peak was not observed during the first heating at the rate of 40 K/min in the as-rolled samples, but one exothermic peak was observed at 620 K, which was associated with the amorphous crystallization process. During the second heating, reverse martensitic transformation was recovered. The onset crystallization temperature was low in the initial stage of crystallization with lower heating rates, but the crystallization fraction was found to increase with increasing temperature. However, the crystallization fraction was almost constant in the initial stage of crystallization with a relatively high heating rate. In all heating rates, the amorphous crystallization rates almost always reached maximum as the volumetric fraction of amorphous crystallization rose to 50%.

TiNi shape memory alloys exhibit superior shape memory effect, superelasticity, and high damping capacity. The damping behaviour of a ternary TiNiCu 7 alloy were characterized by dynamic mechanical analyzer (DMA) instrument, dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) equipment. The loss factor Tanδ, storage modulus E' and loss modulus E" of shape memory alloy aging followed by furnace cooling and air cooling were Measured. It shows that test method and cooling rate of aging have significant effect on the results of damping capacity of TiNi SMA. Internal friction values (Q -1 ) corresponding to cubic B2 parent phase to rhombohedral R phase transformation are as high as 0.14 for the TiNiCu 7 alloy measured by DMA in single cantilever mode, lower than that of 0.21 measured by DMTA in three-point bending mode.