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Sodium zeolite Y was largely ion exchanged with Pb2+ at 100 OC, evacuated at 400 OC, and treated with D2S at 25 OC. Its structure (1) was determined by pulsed-neutron powder-diffraction methods. After further treatment, evacuation at 400 OC, its structure (2), now of composition Pb2&4Nal1Si137A1~~0384, was determined again. Two different positions are found for deuterium ions in sample 1. Each of 18 deuterium ions in the large cavities bonds to an O( 1) oxygen and lies in the plane of that oxygen and the two Si(A1) atoms to which O( 1) is bound. In sodalite cavities, 16 deuterium ions bind similarly to O(3) oxygens. In structure 2, Pb2+ ions prefer site 11, in the supercage opposite single six-oxygen rings. Although some uncertainty remains about the S2-positions in 2, it appears that S2-is responsible for the movement of some Pb2+ ions into sodalite cavities.If so, each S2-ion, located at the center of a double six-oxygen ring, bridges between two Pb2+ ions to form a linear (Pb-S-Pb)Z+ cluster ( P b S = 2.93(2) A). Excess lead was imbibed into the zeolite as lead oxide/ hydroxide species during the aqueous ion-exchange process. After initial evacuation at 400 OC, only oxide of the initial oxide/hydroxide should have remained. After treatment with D2S and subsequent evacuation at 400 OC, all nonframework oxides appear to have been replaced by sulfides.

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Reliability is a major performance index in the electromechanical product conceptual design decision process. As the function is the purpose of product design, the risk of scheme design is easy to be caused when there is a failure (i.e., function failure). However, existing reliability analysis models focus on the failure analysis of functions but ignore the quantitative risk assessment of conceptual schemes when function failures occur. In addition, design information with subjectivity and fuzziness is difficult to introduce the risk index into the early design stage for comprehensive decisions. To fill this gap, this paper proposes a conceptual scheme decision model for mechatronic products driven by the risk of function failure propagation. Firstly, the function structure model is used to construct the function fault propagation model, so as to obtain the influence degree of the subfunction failure. Secondly, the principle solution weight is calculated when the function failure is propagated, and the influence degree of the failure mode is integrated to obtain the severity of the failure mode on the product system. Thirdly, the risk value of failure mode is calculated by multiplying the severity and failure probability of failure mode, and the risk value of the scheme is obtained based on the influence relationship between failure modes. Finally, the VIKOR (Višekriterijumska Optimizacija i kompromisno Rešenje) method is used to make the optimal decision for the conceptual scheme, and then take the cutting speed regulating device scheme of shearer as an example to verify the effectiveness and feasibility of the proposed decision model.

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