Beijing University of Technology

About: Beijing University of Technology is a education organization based out in Beijing, Beijing, China. It is known for research contribution in the topics: Microstructure & Laser. The organization has 31929 authors who have published 31987 publications receiving 352112 citations. The organization is also known as: Běijīng Gōngyè Dàxué & Beijing Polytechnic University.

Direct Atomic-Scale Imaging about the Mechanisms of Ultralarge Bent Straining in Si Nanowires

Abstract: To safely and reliably use nanowires (NWs) for exploring new functions for different nanodevices, the mechanical properties and structural evolution of the nanowires under external stress become highly important. Large strain (up to 14%) bending experiments of Si NWs were conducted in a high-resolution transmission electron microscope at atomic resolution. The direct dynamic atomic-scale observations revealed that partial and full dislocation nucleation, motion, escape, and interaction were responsible for absorbing the ultralarge strain of up to 14% in bent Si nanowires. The prevalent full dislocation movement and interactions induced the formation of Lomer lock dislocations in the Si NWs. Finally, in contrast to the unlock process of Lomer dislocations that can happen in metallic materials, we revealed that the continuous straining on the Lomer dislocations induced a crystal–amorphous (c-a) transition in Si NWs. Our results provide direct explanation about the ultralarge straining ability of Si at the n...

A Copper(II)-Paddlewheel Metal–Organic Framework with Exceptional Hydrolytic Stability and Selective Adsorption and Detection Ability of Aniline in Water

Abstract: Copper(II)-paddlewheel-based metal–organic frameworks (CP-MOFs) represent a unique subclass of MOFs with highly predictable porous structures, facile syntheses, and functional open metal sites. However, the lack of high hydrolytic stability is an obstacle for CP-MOFs in many practical applications. In this work, we report a new CP-MOF, [Cu4(tdhb)] (BUT-155), which is constructed from a judiciously designed carboxylate ligand with high coordination connectivity (octatopic), abundant hydrophobic substituents (six methyl groups), and substituent constrained geometry (tetrahedral backbone), tdhb8– [H8tdhb = 3,3′,5,5′-tetrakis(3,5-dicarboxyphenyl)-2,2′,4,4′,6,6′-hexamethylbiphenyl)]. BUT-155 shows high porosity with a Brunauer–Emmett–Teller surface area of 2070 m2/g. Quite interestingly, this CP-MOF retains its structural integrity after being treated in water for 10 days at room temperature or in boiling water for 24 h. To the best of our knowledge, BUT-155 represents the first CP-MOF that is demonstrated to ...