IV型等温线(中孔分布 0.4 0.3 600 三0.2 200 0.0 015202.53.03.54.0 040.60.81 Pore diameter(nm) Relative pressure(P/P)IV型等温线（中孔分布〕 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.0 0.1 0.2 0.3 0.4 (a) (b) dV/dD pore volume(cm 3g-1) Pore diameter (nm) 0.0 0.2 0.4 0.6 0.8 1.0 0 100 200 300 400 500 600 700 800 (a) (b) Vol. adsorbed (cm 3/g STP) Relative pressure (P/P0 )