Simultaneous deep macroscopic imaging and microscopic imaging is in urgent demand, but is challenging to achieve experimentally due to the lack of proper fluorescent probes. Herein, we have designed and successfully synthesized simplex Er3+-doped upconversion nanoparticles (UCNPs) with double excitation bands for simultaneous deep macroscopic and microscopic imaging. The material structure and the excitation wavelength of Er3+-singly doped UCNPs were further optimized to enhance the upconversion emission efficiency. After optimization, we found that NaYF4:30%Er3+@NaYF4:2%Er3+ could simultaneously achieve efficient two-photon excitation (2PE) macroscopic tissue imaging and three-photon excitation (3PE) deep microscopic when excited by 808 nm continuous wave (CW) and 1480 nm CW lasers, respectively. In vitro cell imaging and in vivo imaging have also been implemented to demonstrate the feasibility and potential of the proposed simplex Er3+-doped UCNPs as bioprobe.
Qingyuan Chen,Maofan Ye,Dongdong Wang,Xing Yin,Wanfen Pu
Resistance factor (R f ) and residual resistance factor (R ff ) are key metrics for evaluating polymer mobility control. This study examines the performance of hyperbranched polymer HPDACS in porous media under varying permeability, concentration, flow rate, temperature, and salinity conditions, analyzing its R f /R ff establishment capability and postflow viscosity/particle size changes. Results show Rf and Rff increase with concentration (1500 mg/L: R f > 35%, R ff > 20%) but decrease with higher permeability, flow rate, temperature, and salinity. After porous media shear, HPDACS maintains > 40% viscosity retention, with particle size shifting smaller—more pronounced at lower permeability. Subsequently, core flooding experiments were conducted to evaluate oil displacement efficiency at different injected pore volumes (PV). Microscopic imaging and nuclear magnetic resonance (NMR) displacement experiments were used to visualize HPDACS’ displacement behavior. The tests demonstrated HPDACS’ exceptional performance: 0.3 PV injection in 327 mD cores boosted recovery by 19.20%, showing effective residual oil mobilization. Microscopy revealed improved sweep efficiency, while NMR quantified 28.41%, 29.85%, and 19.43% recovery increases in micropores, mesopores, and macropores, respectively. These findings confirm HPDACS’ strong potential for enhancing oil recovery in heterogeneous, low-medium permeability reservoirs through stable displacement fronts and pore-scale residual oil extraction.
危险品化学品经营许可证（带存储）