Traditional e-learning platforms have the flaws that it's usually difficult to query or positioning, and realize the cross-platform sharing and interoperability. In the paper, the semantic web and metadata standard is discussed, and a kind of e - learning system framework based on semantic web is put forward to try to solve the flaws of traditional e-learning platforms.

Abstract  Feldspar and Pb(NO3)2 were mixed and reacted at T=380°C to synthesize Pb-feldspar. In the XRD (X-ray diffraction) pattern of the product, the d values (crystal lattice spacing) of the five peaks are 0.654, 0.342, 0.332, 0.327 and 0.257 nm. The XPS analysis results show that the binding energy of Pb 4f7/2 in the feldspar was between 137.81–138.03 eV. Pb2+ can replace alkali and alkali earth cations in the feldspar structure through ion exchange reaction to form Pb-feldspar.