Earthenware is preferred in Bologna, but enamelled cast-iron or a pot whose heavy bottom is composed of layers of steel alloys are perfectly satisfactory.
Scissors lift platform with a wide range, the main platform, lift mechanism and the bottom are composed of three parts.
The unsymmetrical slope chamber bottom is composed of a series of slopes with different inclination angles, which forms a square cone with the continuous unsymmetrical structure.
For isolated ring B20 cluster, its VB top is mainly constituted of B 2p states mixing with small 2s states, and its CB bottom is composed of B 2p states (Fig. 3 (b2)).
The VB top of pure ZrS2 (Fig. 3 (a2)) is mainly constituted of S 3p states mixing with small Zr 4d states, while its CB bottom is composed of Zr 4d states, indicating that its near-gap electronic structure is different from that of pure MoS2 where the CB bottom and VB top are predominately composed of Mo 4d states [34].
Figure 3 (c1–c4) shows that the VB top of ZrS2/B20 hybrid is dominated by B 2p states from ring B20 cluster, coupled by small Zr 4d and S 3p states, whereas its CB bottom is predominately composed of Zr 4d states, which can be more clearly seen from the electron density distributions of the highest occupied and lowest unoccupied levels (HOL and LUL), respectively, as shown in Figs. 2c, d.
Some researchers put forward the concept of "bottom line of life" to emphasize the son preference in farmers' fertility behavior and suggest that farmers' fertility bottom line is composed of long-term economic and social factors, which existed before the implementation of the family planning policy.
The bottom tier is composed of thousands of soup kitchens, pantries, churches and other organizations that either hand out food or serve meals.
The KH and SU lines are narrow channels, with bottom materials mainly composed of sludge with high organic matter content.
The sea bottom is mainly composed of sand, sandy mud, muddy sand and bedrock outcrops (Usiriprisan et al., 1987; Di Geronimo et al., 2009; Feldens et al., 2009, 2012).
