Heating and cooling represent a significant portion of overall energy consumption of our society. Due to the diffusive nature of thermal energy, thermal insulation is critical for energy management to reduce energy waste and improve energy efficiency. Thermal insulation relies on the reduction of thermal conductivity of appropriate materials that are engineerable in compositions and structures. Hollow‐structured materials (HSMs) show a great promise in thermal insulation since the existence of high‐density gaseous voids breaks the continuity of heat‐transport pathways in the HSMs to lower their thermal conductivities efficiently. Herein, a timely overview of the recent progress in developing HSMs for thermal insulation is presented, with the focus on summarizing the strategies for creating gaseous voids in solid materials and thus synthesizing various HSMs. Systematic analysis of the documented results reveals the relationship of thermal conductivities of the HSMs and the size and density of voids, i.e., reducing the void size below ≈350 nm is more favorable to decrease the thermal conductivity of the HSMs because of the possible confinement effect originated from the nanometer‐sized voids. The challenges and promises of the HSMs faced in future research are also discussed.

Light-weight ceramic aerogels hold promise for superinsulation. However, its mechanical instability and complex manufacturing hampered its technical applications. In this study, we demonstrate lightweight pore-gradient ceramic aerogel-like foam monoliths (PGAFoams) through one-pot and in situ bubble supported pore gradient formation. The mechanically strong PGAFoams exhibit a low thermal conductivity of 0.036 W m–1 K–1 and a compressive strength of 89.85 MPa. The pore gradient and integral ceramic monolith nature provides such hydrophobic PGAFoams with thermal management, robust soundproof, and fire-resistance performance. Highly machinable PGAFoams can be adapted into a variety of shapes and dimensions to accommodate complex geometry applications. The scalable manufacturing of lightweight PGAFoams opens up building insulation with remarkable thermal management, high mechanical strength, low mass density, superior soundproofing, and fire-retardant performances.

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole (E1) transitions in Al-like W61+ through Cl-like W57+, with partially filled 3p subshell. The fully relativistic multiconfiguration Dirac–Fock (MCDF) method, taking quantum electrodynamical effect and Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states in Al-like through Cl-like W ions from the method were compared with some available theoretical and experimental results, and good agreement with them was achieved.

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