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The observed radio-optical-X-ray spectral energy distributions (SEDs) of 22hot spots and 45 knots in the jets of 35 active galactic nuclei are compliedfrom literature and modeled with single-zone lepton models. It is found thatthe observed luminosities at 5 GHz (L_5GHz) and at 1 keV (L_1keV) are tightlycorrelated, and the two kinds of sources can be roughly separated with adivision of L_1keV=L_5GHz. Our SED fits show that the mechanisms of the X-raysare diverse. Considering the sources at rest, the synchrotron-self-Compton(SSC) scattering would dominate the IC process. This model can interpret theX-rays of some hot spots with a magnetic field strength (B_ssc^delta=1) beingconsistent with the equipartition magnetic field (B_eq^delta=1) in one order ofmagnitude, but an unreasonably low B_ssc^delta=1 is required to model theX-rays for all knots. The ratio R_B=B_eq^delta=1/B_ssc^delta=1 is greater than1 and it is tightly anti-correlated with ratio R_L= L_1keV/L_5GHz for both theknots and the hot spots. We propose that the deviation may be due to theneglect of the relativistic bulk motion for these sources. Considering thiseffect, we show that the IC/CMB model well explains the X-ray emission for mostsources. Both B_eq' and delta are tentatively correlated with R_L. Corrected bythe beaming effect, the L'_5GHz-L'_1keV relations for the two kinds of sourcesare even tighter than the observed ones. These facts suggest that, under theequipartition condition, the observational differences of the X-rays from theknots and hot spots may be mainly due the differences on the Doppler boostingeffect and the co-moving magnetic field of the two kinds of sources. Our ICscattering models predict a prominent GeV-TeV component in the SEDs for somesources, which are detectable with H.E.S.S. and Fermi/LAT.

X-ray Radiation Mechanisms and Beaming Effect of Hot Spots and Knots in Active Galactic Nuclear Jets