Search

Author(s): Bevin Huang [1]; Genevieve Clark [2]; Efrn Navarro-Moratalla [3]; Dahlia R. Klein [3]; Ran Cheng [4]; Kyle L. Seyler [1]; Ding Zhong [1]; Emma Schmidgall [1]; Michael A. McGuire [...]

Tissue scaffolds need to have anisotropic mechanical properties and a porous structure to meet the needs of different tissues and organs. This report presents results of a study on an especially-designed 3D printing method with oxidized nanocellulose and gelatin, analyzes the servo principle of pneumatic condensing extrusion 3D printer, and proposes a hexagonal algorithm. For the purpose of this study, a printing process file was written by G code, physical and mechanical performance of the 3D scaffolds was evaluated with Solidworks simulation, the porous structure and pressure-pull performance of the printed 3D scaffolds was observed by SEM, and experiments were conducted to measure their bio-compatibility. The study draws the conclusion that scaffolds thus printed have a highly porous structure and anisotropic mechanical properties. [ABSTRACT FROM AUTHOR]

Semi-metallic graphene and semiconducting monolayer transition-metal dichalcogenides are the most intensively studied two-dimensional materials of recent years. Lately, black phosphorus has emerged as a promising new two-dimensional material due to its widely tunable and direct bandgap, high carrier mobility and remarkable in-plane anisotropic electrical, optical and phonon properties. However, current progress is primarily limited to its thin-film form. Here, we reveal highly anisotropic and strongly bound excitons in monolayer black phosphorus using polarization-resolved photoluminescence measurements at room temperature. We show that, regardless of the excitation laser polarization, the emitted light from the monolayer is linearly polarized along the light effective mass direction and centres around 1.3 eV, a clear signature of emission from highly anisotropic bright excitons. Moreover, photoluminescence excitation spectroscopy suggests a quasiparticle bandgap of 2.2 eV, from which we estimate an exciton binding energy of ∼0.9 eV, consistent with theoretical results based on first principles. The experimental observation of highly anisotropic, bright excitons with large binding energy not only opens avenues for the future explorations of many-electron physics in this unusual two-dimensional material, but also suggests its promising future in optoelectronic devices. [ABSTRACT FROM AUTHOR]

• SAW velocities for BCC crystals with unusual (irregular) orientations are studied. • An optimized numerical method of SAW velocities for BCC crystals is given. • The temperature dependences of SAW velocities are also simulated numerically. Based on the propagation theory of acoustic waves in anisotropic media, the angular dispersion curves of SAW velocities propagated in some unusual oriented, such as (0 1 6)- and (3 3 1)-oriented, Body-Centered Cubic (BCC) single crystals are simulated using an optimized numerical method. Meanwhile, the angular dispersion curves of SAW velocities propagated in these unusual oriented BCC single crystals are measured by Impulsive Stimulated Scattering (ISS) laser ultrasonic method, which show that the measurement results are in good agreement with those of the simulations. By the optimized numerical method, the relationships between the temperature and the dispersion curves of SAW velocity propagated in these single crystals are also simulated. [ABSTRACT FROM AUTHOR]