China University of Petroleum

About: China University of Petroleum is a education organization based out in Beijing, China. It is known for research contribution in the topics: Catalysis & Oil shale. The organization has 39802 authors who have published 39151 publications receiving 483760 citations. The organization is also known as: Zhōngguó Shíyóu Dàxué & China University of Petroleum (Beijing).

Damage-tolerant nanotwinned metals with nanovoids under radiation environments

Abstract: Material performance in extreme radiation environments is central to the design of future nuclear reactors. Radiation induces significant damage in the form of dislocation loops and voids in irradiated materials, and continuous radiation often leads to void growth and subsequent void swelling in metals with low stacking fault energy. Here we show that by using in situ heavy ion irradiation in a transmission electron microscope, pre-introduced nanovoids in nanotwinned Cu efficiently absorb radiation-induced defects accompanied by gradual elimination of nanovoids, enhancing radiation tolerance of Cu. In situ studies and atomistic simulations reveal that such remarkable self-healing capability stems from high density of coherent and incoherent twin boundaries that rapidly capture and transport point defects and dislocation loops to nanovoids, which act as storage bins for interstitial loops. This study describes a counterintuitive yet significant concept: deliberate introduction of nanovoids in conjunction with nanotwins enables unprecedented damage tolerance in metallic materials.

Hierarchically Staggered Nanostructure of Mineralized Collagen as a Bone-Grafting Scaffold

Abstract: A hierarchical, intrafibrillarly mineralized collagen (HIMC) is achieved through a selective mineralization progress in the collagenous gap regions mediated by poly(acrylic acid) with appropriate molecular weight. The associated topographical features directly correlate with nanomechanical heterogeneities of the HIMC to accommodate a broad range of external loads. Moreover, this hierarchically staggered nanostructure provides an optimized microenvironment to improve bone regeneration by instructing host cells.