- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Scanning acoustic microscopy of quantum dot aggregates
摘要： Quantum dot (QD) aggregate formation is essential, especially, in nanoparticle-based drug delivery systems. Imaging of these targeted QD aggregates exposes information about the the treatment of many diseases including cancer. Scanning Acoustic Microscopy (SAM) is a non-invasive and rapid imaging modality, which can obtain qualitative and quantitative features simultaneously. In our study, acoustic impedance microscopy of QD aggregates was performed by SAM for evaluating the potential of SAM in the detection of lead-sulphide (PbS), graphene and cadmium-telluride/cadmium sulphide (CdTe/CdS) quantum dot aggregates for the first time. Absorption spectra of QDs, obtained with an ultraviolet-visible spectrometer, and fluorescence spectra of QD aggregates, obtained with an inverted fluorescence microscope, are also demonstrated. The success of imaging quantum dot aggregates by SAM indicated the potential of SAM in monitoring the micro-environment of the disease and also the therapeutic effect of the drug-loaded QD aggregates.
关键词： scanning acoustic microscopy,quantum dot aggregates,fluorescence microscopy
更新于2025-09-12 10:27:22
-
Residual Stress Analysis Based on Acoustic and Optical Methods
摘要： Co-application of acoustoelasticity and optical interferometry to residual stress analysis is discussed. The underlying idea is to combine the advantages of both methods. Acoustoelasticity is capable of evaluating a residual stress absolutely but it is a single point measurement. Optical interferometry is able to measure deformation yielding two-dimensional, full-field data, but it is not suitable for absolute evaluation of residual stresses. By theoretically relating the deformation data to residual stresses, and calibrating it with absolute residual stress evaluated at a reference point, it is possible to measure residual stresses quantitatively, nondestructively and two-dimensionally. The feasibility of the idea has been tested with a butt-jointed dissimilar plate specimen. A steel plate 18.5 mm wide, 50 mm long and 3.37 mm thick is braze-jointed to a cemented carbide plate of the same dimension along the 18.5 mm-side. Acoustoelasticity evaluates the elastic modulus at reference points via acoustic velocity measurement. A tensile load is applied to the specimen at a constant pulling rate in a stress range substantially lower than the yield stress. Optical interferometry measures the resulting acceleration field. Based on the theory of harmonic oscillation, the acceleration field is correlated to compressive and tensile residual stresses qualitatively. The acoustic and optical results show reasonable agreement in the compressive and tensile residual stresses, indicating the feasibility of the idea.
关键词： electronic speckle-pattern interferometry,residual stress analysis,acoustoelasticity,scanning acoustic microscopy
更新于2025-09-10 09:29:36