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In this study, the synthesis of single-phase zirconolite powder was explored using two-step route of combustion synthesis (CS) plus acid treatment. Zirconolite/Cu composite was firstly produced from the combustion reaction using CuO and Ti as the oxidant and reductant. After pickling and desiccation, refined zirconoliterich ceramic powder was obtained with bimodal particle size distribution. The ceramic powder was finally preformed and calcined at 1050-1300°C for 6-48 hours, which resulted in bulk density and Vickers hardness of 4.02 g/cm 3 and 11.54 GPa after sintering at 1100°C for 18 hours. Aqueous durability of the calcined waste matrice was evaluated according to MCC-1 standard. The 42 days normalized leaching rates of Ca, Ti and Zr were measured to be 3.96 9 10 À3 , 4.52 9 10 À6 and 1.54 9 10 À6 gÁm À2 Ád À1 . K E Y W O R D Schemical durability, combustion synthesis, nuclear waste, sintering

In China, cross-track high-speed trains (CTHSTs) play an important role in railway passenger transportation, with an increasing number of cross-track passengers sourced from the expansion of high-speed railway (HSR) network. The CTHST generally has long travel times, so running CTHSTs is not beneficial for train rescheduling work and plan’s periodicity in the periodic operation context. Thus, the main challenge in cross-track line planning is looking for a symmetry point between passenger transportation and disadvantages of running CTHSTs, which are two conflicting aspects. In this study, we developed a multiobjective integer programming model to produce a balanced cross-track line plan by combining individual-track high-speed trains (ITHSTs) into CTHSTs, which is a discrete optimization problem. This strikes a balance among four goals: the periodicity of the line plan, CTHST quantity, CTHST mileage, and CTHST stops in the context of periodic operation, while satisfying the constraints of passenger demand and the number of available ITHSTs. Numerical experiments are conducted based on a real-world network and optimal solutions were quickly obtained. We analyzed impacts of each goal and parameter on the result and influencing factors of computation. Comparisons with existing methods and real-life plans were also presented to show improvements made by proposed model.

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