Thermoelectric properties of the type-I clathrates Ba$_8$Cu$_x$Si$_{46-x}$ ($3.6 \leq x \leq 7$, $x$ = nominal Cu content) are investigated both experimentally and theoretically. The polycrystalline samples are prepared either by melting, ball milling and hot pressing or by melt spinning, hand milling and hot pressing techniques. Temperature-dependent electrical resistivity, $\rho(T)$, and the Seebeck coefficient, $S(T)$, measurements reveal metal-like behavior for all samples. For $x = 5$ and 6, density functional theory calculations are performed for deriving the enthalpy of formation and the electronic structure which is exploited for the calculation of Seebeck coefficients and conductivity within Boltzmann's transport theory. For simulating the properties of doped clathrates the rigid band model is applied. On the basis of the density functional theory results the experimentally observed compositional dependence of $\rho(T)$ and $S(T)$ of the whole sample series is analyzed. The highest dimensionless thermoelectric figure of merit $ZT$ of 0.28 is reached for a melt-spun sample at $600^{\circ}$C. The relatively low $ZT$ values in this system are attributed to the too high charge carrier concentrations.Comment: 11 pages, 13 figures, submitted to Phys. Rev.

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A series of shaking table tests of model field were conducted using four shaking tables. Details of experimental setup are first presented with particular focus on design of the similitude ratio, the 40-m-long model boxes, and the synthetic model soil. The experiments were conducted in two phases: Phase 1 is shaking table test of the model boxes without soil; while Phase 2 is the model field shaking table test. Test results including response acceleration and its spectrum are discussed. The comparisons show that non-uniform excitation in different wave form, peak acceleration, vibration direction and wave propagation direction may lead to different dynamic response. The wave passage effects caused by earthquake should be considered in study of seismic response of long-shape field.