Sustainable structural materials with light weight, great thermal dimensional stability, and superb mechanical properties are vitally important for engineering application, but the intrinsic conflict among some material properties (e.g., strength and toughness) makes it challenging to realize these performance indexes at the same time under wide service conditions. Here, we report a robust and feasible strategy to process cellulose nanofiber (CNF) into a high-performance sustainable bulk structural material with low density, excellent strength and toughness, and great thermal dimensional stability. The obtained cellulose nanofiber plate (CNFP) has high specific strength [~198 MPa/(Mg m−3)], high specific impact toughness [~67 kJ m−2/(Mg m−3)], and low thermal expansion coefficient (<5 × 10−6 K−1), which shows distinct and superior properties to typical polymers, metals, and ceramics, making it a low-cost, high-performance, and environmental-friendly alternative for engineering requirement, especially for aerospace applications.

We have performed the temperature dependence of resistivity ρ(T) and thermoelectric power S(T) by a series of doping in layered cobaltites Bi2Sr2Co2Oy. For all samples, a metallic ρ(T) behavior and a large temperature-independent S is observed at higher temperatures, while we found a upturning ρ(T) but without corresponding variation of S(T) at lower temperatures. The present results strongly demonstrate the contribution of narrow band. Moreover, the doping could effectively modulate the thermoelectric performance. Especially for Bi2Sr1.9Ca0.1Co2Oy, it may provide an excellent platform to be a promising candidate of thermoelectric materials.

This paper focuses on the development of the QM/MM(ABEEM) method to investigate the excision reaction mechanism of damaged thymine. This method does not simply combine the QM method with the...

No abstract