Browsing by Subject "'Dry' ["

The objective of this study was to explore from a theoretical perspective the relationship between dry mode shapes and the distortions associated with wet mode shapes. This study investigated the free vibration characteristics of a rectangular thin plate partially coupled with fluid. A powerful full-field experimental technique referred to as AF-ESPI was used to measure vibration modes and the corresponding resonant frequencies. The derivation of wet mode shapes from dry mode shapes proved effective in analyzing problems for plate-fluid interactions. Our analysis revealed that every wet mode shape is composed of multiple dry mode shapes with corresponding contribution coefficients. In the proposed analytic approach, the superposition method is used to deal with theoretical aspects of thin plate vibration behavior, and velocity potential is used to express the dynamic behavior of an incompressible flow field in a finite container. The accuracy of the results obtained using the proposed theoretical approach was verified via comparison with numerical results obtained using finite element method (FEM) and experimental measurements. A detailed discussion pertaining to the relationship between wet and dry mode shapes is also presented. ? 2021

The fabrication of graphene/SnS2van der Waals photodetectors and their photoelectrical properties are systematically investigated. It was found that a dry transferred graphene/SnS2van der Waals heterostructure had a broadband sensing range from ultraviolet (365 nm) to near-infrared (2.24 μm) and respective improved responsivities and photodetectivities of 7.7 × 103A/W and 8.9 × 1013jones at 470 nm and 2 A/W and 1.8 × 1010jones at 1064 nm. Moreover, positive and negative photoconductance effects were observed when the photodetectors were illuminated by photon sources with energies greater and smaller than the bandgap of SnS2, respectively. The photoresponsivity (R) versus incident power density (P) follows the empirical lawR?Pinβ, with β > ?1 for positive photoconductance effects and β < ?1 for negative photoconductance effects. On the basis of the Fowler-Nordheim tunneling model and a Poisson and drift-diffusion simulation, we show quantitatively that the barrier height and barrier width of the heterostructure photodetector could be controlled by a laser and an external electrical field through a photogating effect generated by carriers trapped at the interface, which could be used to tune the separation and transport of photogenerated carriers. Our results may be useful for the design of high performance van der Waals heterojunction photodetectors. ? 2021 American Chemical Society