A numerical model was presented to predict the specific proton conductivity of the catalyst layer in Proton Exchange Membrane Fuel Cells (PEMFC).This model was derived from the random packed spheres with simple cubic,...A numerical model was presented to predict the specific proton conductivity of the catalyst layer in Proton Exchange Membrane Fuel Cells (PEMFC).This model was derived from the random packed spheres with simple cubic, body-centered cubic and face-centered cubic structures.The effects of sphere radius r_s, bulk proton conductivity k_b, contact parameter γ and contact angle α on proton transfer within a homogeneous agglomerate sphere consisting of carbon-supported catalyst and electrolyte were analyzed.A correlation equation of specific proton conductivity was obtained by data fitting.The real effective proton conductivity in the catalyst layer was measured by addition to a standard Membrane Electrolyte Assembly of an inactive composite layer in the electrolyte path between the anode and cathode. The model was validated by good agreement between calculations and measured data.展开更多
Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect pene...Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect penetration abilities of nanostructured lipid carriers（NLC）. Real--time penetration of folate--or cell penetrating peptide（CPP）-modified NLC was evaluated using a multicellular tumor spheroid（MTS） established by stacking culture method as an in vitro testing platform. The results suggested that CPP modification had a better penetration behavior both on penetration depth and intensity compared with folate-modified NLC at the early stage of penetration process.展开更多
文摘A numerical model was presented to predict the specific proton conductivity of the catalyst layer in Proton Exchange Membrane Fuel Cells (PEMFC).This model was derived from the random packed spheres with simple cubic, body-centered cubic and face-centered cubic structures.The effects of sphere radius r_s, bulk proton conductivity k_b, contact parameter γ and contact angle α on proton transfer within a homogeneous agglomerate sphere consisting of carbon-supported catalyst and electrolyte were analyzed.A correlation equation of specific proton conductivity was obtained by data fitting.The real effective proton conductivity in the catalyst layer was measured by addition to a standard Membrane Electrolyte Assembly of an inactive composite layer in the electrolyte path between the anode and cathode. The model was validated by good agreement between calculations and measured data.
基金National key Basic Research Program(Grant No.2013CB932501)National Natural Science Foundation of China(Grant No.81273454 and 81473156)+1 种基金Beijing National Science Foundation(Grant No.7132113)Doctoral Foundation of the Ministry of Education(Grant No.20130001110055)
文摘Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect penetration abilities of nanostructured lipid carriers（NLC）. Real--time penetration of folate--or cell penetrating peptide（CPP）-modified NLC was evaluated using a multicellular tumor spheroid（MTS） established by stacking culture method as an in vitro testing platform. The results suggested that CPP modification had a better penetration behavior both on penetration depth and intensity compared with folate-modified NLC at the early stage of penetration process.
