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A New Chain-Like Heteropolytungstate Formed by Keggin Cluster Units: Synthesis and Structure of [H 2 bpy] 3 [SiMnW 11 O 39 ]·1.25H 2 O. -The title compound is hydrothermally synthesized from an aqueous solution containing K8[β2-SiW11O39]·14H2O, MnCl2, and 4,4'-bipyridine (autoclave, 130°C, 5 d, 39% yield). [H2bpy]3[SiMnW11O39]·1.25H2O crystallizes in the monoclinic space group P21/n with Z = 4 (single crystal XRD) and exhibits a new zigzag chain structure, which is different to the straight chain structure reported for one-dimensional transition metal substituted Keggin heteropolytungstates. Furthermore, the zigzag chains of the title compound form layers which are stacked parallel giving a three-dimensional structure with dumbbell-like one-dimensional channels. -(MENG, J. X.; MA, Y.; XU, X. X.; LI, Y. G.; WANG*, E. B.; Chin.

Brush electroplating causes a marked reduction in the fatigue strength of the base steel. For the medium carbon steel reported in this paper, the fatigue limit is reduced 28.6% by nickel brush electroplating. A large number of short cracks are found in the nickel coating, and the coating usually suffers a high value of internal tensile stress. These are two reasons that cause the loss of fatigue strength. Shot peening has been used to minimize the loss of fatigue strength caused by brush electroplating.

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