To examine the mechanisms of condensation and evaporation of water in mesoporous carbons without surface functional groups and micropores, we measured gravimetrically the adsorption–desorption isotherms of water on ordered mesoporous carbons with and without surface functional groups and micropores at various temperatures between 265 and 295 K. Water wets partially the pore walls of the mesoporous carbons. Nevertheless, pore condensation of water occurs very slowly at pressures close to or equal to saturation, depending on both the properties of pore walls and the pore size. The uptake of water in the mesoporous carbons without micropores decreases with a decrease in temperature, although the uptake in the mesoporous carbon with micropores does not change at all with temperature. Capillary evaporation of water occurs at pressures expected from the Kelvin equation that describes the link between wetting and capillary condensation.

Topological superconductors have attracted wide-spreading interests for the bright application perspectives to quantum computing. Cu 0.3 Bi 2 Se 3 is a rare bulk topological superconductor with an odd-parity wave function, but the details of the vector order parameter d and its pinning mechanism are still unclear. Here, we succeed in growing Cu x Bi 2 Se 3 single crystals with unprecedented high doping levels. For samples with x = 0.28, 0.36 and 0.37 with similar carrier density as evidenced by the Knight shift, the in-plane upper critical field H c2 shows a two-fold symmetry. However, the angle at which the H c2 becomes minimal is different by 90°among them, which indicates that the d-vector direction is different for each crystal likely due to a different local environment. The carrier density for x = 0.46 and 0.54 increases substantially compared to x ≤ 0.37. Surprisingly, the in-plane H c2 anisotropy disappears, indicating that the gap symmetry undergoes a transition from nematic to isotropic (possibly chiral) as carrier increases.