石墨烯基材料的生物医用性能及其应用

石墨烯基材料由于具有优异的物理和化学性能,近年来获得了广泛的研究和应用。介绍了石墨烯基材料及其生物特性,讨论了石墨烯材料产生毒性的影响因素和预防措施,对石墨烯基材料在生物医用领域(如药物载体、生物传感器、光热治疗和组织工程材料)的应用情况进行了论述,并对石墨烯基材料的研究发展方向与应用前景进行了展望。     

搅拌槽内液-固两相体系的数值研究(Ⅰ)流场的数值模拟

Three-dimensional solid-liquid flow is mathematically formulated by means of the “two-fluid” approach and the two-phase k-ε-Ap turbulence model. The turbulent fluctuation correlations appearing in the Reynolds time averaged governing equations are fully incorporated. The solid-liquid flow field and solid concentration distribution in baffled stirred tanks with a standard Rushton impeller are numerically simulated using an improved “inner-outer” iterative procedure. The flow pattern is identified via the velocity vector plots and a recirculation loop with higher solid concentration is observed in the central vicinity beneath the impeller. Comparison of the simulation with experimental data on the mean velocities and the turbulence quantities of the solid phase is made and quite reasonable agreement is obtained except for the impeller swept volume. The counterpart of liquid phase is presented as well. The predicted solid concentration distribution for three experimental cases with the average solid concentration up to 20% is also found to agree reasonably with the experimental results published in the literature.