Morphological environment survey and hydrodynamic modeling of a large bifurcation-confluence complex in Yangtze River, China.

Since the establishment of the world-class Three Gorges Dam (TGD) across the Yangtze River, China, the downstream reach has experienced a long-term adjustment with regard to the river morphology and hydrodynamics, imposing a profound impact on the environmental conditions of human living and aquatic ecosystem. This study presents an investigation on the river channel morphological characteristics and hydrodynamic environment of a large bifurcation-confluence complex downstream of the TGD through detailed field survey and numerical modeling. Results show that the main stem, before being bifurcated into two sub-channels (the North Channel and the South Channel), experiences a meander, leading to the severe bed scouring near the outer bank (pools) resulted from a high flow mass flux and bed shear stress.

Synthesis, characterization of the luminescent lanthanide complexes with (Z)-4-(4-methoxyphenoxy)-4-oxobut-2-enoic acid.

(Z)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its solid rare earth complexes LnL3.2H2O (Ln=La, Eu, Tb) were synthesized and characterized by means of MS, elemental analysis, FTIR, 13C NMR and TG-DTA. The IR and 13C NMR results show that the carboxylic groups in the complexes coordinated to the rare earth ions in the form of a bidentate ligand, but the ester carboxylic groups have not taken part in the coordination.