Browsing by Author "Zou, Jun"

Now showing 1 - 6 of 6
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    An adaptive edge element method and its convergence for an electromagnetic constrained optimal control problem
    (ESAIM: Mathematical Modelling and Numerical Analysis (ESAIM: M2AN), 2021-09-01) Li, Bowen; Zou, Jun
    In this work, an adaptive edge element method is developed for an H(curl)-elliptic constrained optimal control problem. We use the lowest-order Nédélec's edge elements of first family and the piecewise (element-wise) constant functions to approximate the state and the control, respectively, and propose a new adaptive algorithm with error estimators involving both residual-type error estimators and lower-order data oscillations. By using a local regular decomposition for H(curl)-functions and the standard bubble function techniques, we derive the a posteriori error estimates for the proposed error estimators. Then we exploit the convergence properties of the orthogonal L2-projections and the mesh-size functions to demonstrate that the sequences of the discrete states and controls generated by the adaptive algorithm converge strongly to the exact solutions of the state and control in the energy-norm and L2-norm, respectively, by first achieving the strong convergence towards the solution to a limiting control problem. Three-dimensional numerical experiments are also presented to confirm our theoretical results and the quasi-optimality of the adaptive edge element method.
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    Effects of cotrimoxazole prophylaxis on Talaromyces marneffei infection in HIV/AIDS patients receiving antiretroviral therapy: a retrospective cohort study
    (Emerging Microbes & Infections, 2019-01) Jiang, Junjun; Qin, Fengxiang; Meng, Sirun; Nehl, Eric J; Huang, Jinping; Liu, Yanfen; Zou, Jun; Dong, Wenyi; Huang, Jiegang; Chen, Hui; Zang, Ning; Liang, Bingyu; Ning, Chuanyi; Liao, Yanyan; Luo, Chaolian; Liu, Huifang; Liu, Xin; Wang, Jian; Zhou, Oulu; Le, Thuy; Ye, Li; Wu, Fengyao; Liang, Hao
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    High-speed label-free functional photoacoustic microscopy of mouse brain in action.
    (Nat Methods, 2015-05) Yao, Junjie; Wang, Lidai; Yang, Joon-Mo; Maslov, Konstantin I; Wong, Terence TW; Li, Lei; Huang, Chih-Hsien; Zou, Jun; Wang, Lihong V
    We present fast functional photoacoustic microscopy (PAM) for three-dimensional high-resolution, high-speed imaging of the mouse brain, complementary to other imaging modalities. We implemented a single-wavelength pulse-width-based method with a one-dimensional imaging rate of 100 kHz to image blood oxygenation with capillary-level resolution. We applied PAM to image the vascular morphology, blood oxygenation, blood flow and oxygen metabolism in both resting and stimulated states in the mouse brain.
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    High-speed widefield photoacoustic microscopy of small-animal hemodynamics.
    (Biomedical optics express, 2018-10) Lan, Bangxin; Liu, Wei; Wang, Ya-Chao; Shi, Junhui; Li, Yang; Xu, Song; Sheng, Huaxin; Zhou, Qifa; Zou, Jun; Hoffmann, Ulrike; Yang, Wei; Yao, Junjie
    Optical-resolution photoacoustic microscopy (OR-PAM) has become a popular tool in small-animal hemodynamic studies. However, previous OR-PAM techniques variously lacked a high imaging speed and/or a large field of view, impeding the study of highly dynamic physiologic and pathophysiologic processes over a large region of interest. Here we report a high-speed OR-PAM system with an ultra-wide field of view, enabled by an innovative water-immersible hexagon-mirror scanner. By driving the hexagon-mirror scanner with a high-precision DC motor, the new OR-PAM has achieved a cross-sectional frame rate of 900 Hz over a 12-mm scanning range, which is 3900 times faster than our previous motor-scanner-based system and 10 times faster than the MEMS-scanner-based system. Using this hexagon-scanner-based OR-PAM system, we have imaged epinephrine-induced vasoconstriction in the whole mouse ear and vascular reperfusion after ischemic stroke in the mouse cortex in vivo, with a high spatial resolution and high volumetric imaging speed. We expect that the hexagon-scanner-based OR-PAM system will become a powerful tool for small animal imaging where the hemodynamic responses over a large field of view are of interest.
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    Mathematical Analysis of Electromagnetic Plasmonic Metasurfaces
    (Multiscale Modeling & Simulation, 2020-01) Ammari, Habib; Li, Bowen; Zou, Jun
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    Superresolution in Recovering Embedded Electromagnetic Sources in High Contrast Media
    (SIAM Journal on Imaging Sciences, 2020-01) Ammari, Habib; Li, Bowen; Zou, Jun