Searcharxiv⌕ Search

arXiv subjects

Guozhong Wang

Publications and source records attributed to Guozhong Wang.

4 recordsLinked to original sources
arXiv2024

TexLiverNet: Leveraging Medical Knowledge and Spatial-Frequency Perception for Enhanced Liver Tumor Segmentation

Integrating textual data with imaging in liver tumor segmentation is essential for enhancing diagnostic accuracy. However, current multi-modal medical datasets offer only general text annotations, lacking lesion-specific details critical for extracting nuanced features, especially for fine-grained segmentation of tumor boundaries and small lesions. To address these limitations, we developed datasets with lesion-specific text annotations for liver tumors and introduced the TexLiverNet model. TexLiverNet employs an agent-based cross-attention module that integrates text features efficiently with visual features, significantly reducing computational costs. Additionally, enhanced spatial and adaptive frequency domain perception is proposed to precisely delineate lesion boundaries, reduce background interference, and recover fine details in small lesions. Comprehensive evaluations on public and private datasets demonstrate that TexLiverNet achieves superior performance compared to current state-of-the-art methods.

eess.IV↗
arXiv2020

Confronting theoretical results of localized and additional surface plasmon resonances in silver nanoparticles with EELS measurements

Raza et al. recently observed the extraordinarily large energy blueshifts of localized surface plasmon resonances and additional surface plasmon resonances in silver nanoparticles encapsulated in silicon nitride, which are not fully understood yet. By using the quantum model consisting of two subsystems respectively for describing the center of mass and intrinsic motions of conduction electrons of a metallic nanosphere and a coupling occurred between the center of mass and conduction electrons outside the metallic nanosphere, we firstly deduced the general energy and line broadening size-dependence of localized surface plasmon resonances, which removes the divergent defect of usual 1/R size-dependence. Secondly, we proposed that the additional surface plasmon resonance in a metallic nanosphere originates from the transition of the first excited state to the ground state of the center of mass subsystem with energy levels corrected by degenerate state pairs of the system composed of the center of mass and intrinsic motions of conduction electrons. Then, we implemented this generation mechanism of additional surface plasmon resonances for silver nanoparticles encapsulated in silicon nitride and the calculated results are well consistent with experimental results. Furthermore, we obtained a new energy expression of localized surface plasmon resonances, with which we successfully explained the extraordinarily large energy blueshifts of localized surface plasmon resonances in few-nanometer silver nanoparticles encapsulated in silicon nitride. Finally, we calculated the localized and additional surface plasmon resonance energies of silver nanoparticles resting on carbon films and the calculated results perfectly explain the experimental measurements of Scholl et al..

cond-mat.mes-hall↗
arXiv2014

Electron Temperature Dependence of the Optical Properties of Small Sodium Nanoparticles

We report a novel behavior of the surface plasmon linewidth in sodium nanospheres Na$_{1760}$ changing with the electron temperature, which monotonically decreases and bears a discontinuous sudden drop at high electron temperatures. Our calculation is based on the model constructed by splitting the total Hamiltonian of all valence electrons of a metallic nanoparticle into two sub-Hamiltonians and their coupling, and obtained results can be verified by the pump-probe femtosecond spectroscopy experiments. In addition, we propose that it is the size uncertainty of small nanoparticles that yields the intrinsic linewidth of the surface plasmon resonance, which is supported by the available data of clusters Na$_{8}$ and Na$_{20}$.

cond-mat.mes-hall↗