We collect 172 clean Fermi blazars with broadband quasi-simultaneous spectral data from radio to γ-ray. Both spectral energy distributions (SEDs) of syn-chrotron and inverse Compton (IC) components are fitted by a log-parabolic law in lgν-lgνfν diagram. The second-degree term of log-parabolic measures the curva-ture of SED. Our main intent is to explore the curvature properties of spectral energy distribution of Fermi blazars. Our main results are as follows: a significant correla-tion between the synchrotron peak frequency and its curvature for flat spectrum radio quasars (FSRQs) and BL Lacertae ob jects (BL Lacs) is found, but the correlation for-mulas are different for FSRQs and BL Lacs. Comparing our observational results and the theoretical predictions of different models, we find that the observational result-s of FSRQs are consistent with the fluctuation of fractional acceleration gain model, while the observational results of BL Lacs are consistent with the energy-dependent acceleration probability model. The mean value of synchrotron curvature of FSRQs is larger than that of BL Lacs, which suggests the particle acceleration efficiency of BL Lacs is higher than that of FSRQs. It should be attributed to the jet plasma of FSRQs dissipated within the broad-line region (BLR) and suffered stronger cooling. We also find that FSRQs and Low-energy peaked BL Lacs (LBLs) have similar SED properties, which is consistent with previous results. We do not find a significant correlation be-tween the IC peak frequency and its curvature for FSRQs and BL Lacs, which may be caused by complicated seed photon field and radiation processes.%收集了172个Fermi耀变体多波段准同时性观测数据,同步辐射成分和逆康普顿(IC)散射成分的多波段能谱通过对数抛物线拟合.研究了Fermi耀变体能谱分布的曲率特性,主要结果如下:平谱射电类星体(FSRQ)和蝎虎座BL型天体(BL Lac)的同步峰值频率和曲率有显著的负相关,但它们的相关关系是不同的.比较观测结果和不同理论模型预测,FSRQ加速机制与分数变换加速增益模型(The model of fluctuation of fractional acceleration gain)一致,而BL Lac则与能量依赖加速概率模型(The model of energy-dependent acceleration probability)一致;FSRQ同步曲率的平均值大于BL Lac的平均值,暗示了BL Lac的粒子加速效率高于FSRQ的粒子加速效率.这归因于FSRQ在宽线区(BLR)的喷流较强.此外FSRQ和低能峰蝎虎座BL型天体(LBL)具有相似的能谱分布特性.这与先前的研究结果一致;对于FSRQ和BL Lac,没有发现IC峰值频率与其曲率之间存在相关性.
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