RESUMO
Two-dimensional materials provide extraordinary opportunities for exploring phenomena arising in atomically thin crystals. Beginning with the first isolation of graphene, mechanical exfoliation has been a key to provide high-quality two-dimensional materials, but despite improvements it is still limited in yield, lateral size and contamination. Here we introduce a contamination-free, one-step and universal Au-assisted mechanical exfoliation method and demonstrate its effectiveness by isolating 40 types of single-crystalline monolayers, including elemental two-dimensional crystals, metal-dichalcogenides, magnets and superconductors. Most of them are of millimeter-size and high-quality, as shown by transfer-free measurements of electron microscopy, photo spectroscopies and electrical transport. Large suspended two-dimensional crystals and heterojunctions were also prepared with high-yield. Enhanced adhesion between the crystals and the substrates enables such efficient exfoliation, for which we identify a gold-assisted exfoliation method that underpins a universal route for producing large-area monolayers and thus supports studies of fundamental properties and potential application of two-dimensional materials.
RESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
OBJECTIVE: To explore the satisfactory rate in patients with body dysmorphic disorder (BDD) after cosmetic surgery. METHODS: We designed a questionnaire to investigate the postoperative satisfactory rate in patients with BDD and without BDD. RESULTS: There was significant difference in postoperative satisfactory rate between patients with BDD and without BDD. CONCLUSION: The patients with BDD have a lower satisfactory rate, which is even worse after repeated surgery.