Nest site selection by Black-necked Crane Grus nigricollis in the Ruoergai Wetland, China

From 5 May 2003 to early June 2005, nest site selection of Black-necked Cranes Grits nigricollis was studied at the Ruoergai Wetland Nature Reserve (RWNR), an important breeding area for the species in China. Results showed that the crane nests only in we

Epoxidation of cyclohexene on Ti/SiO2 catalysts prepared by chemical grafting TiCl4 on deboronated silica xerogel

Ti/SiO2 (or Ti/de[B]SiO2) catalysts were prepared by grafting deboronated silica xerogel with gaseous TiCl4. Using TBHP as oxidant, the Ti/de[B]SiO2 catalyst shows both catalytic activity and selectivity in epoxidation of cyclohexene better than 80%, and the activity can be comparable with that of Ti-beta. The catalytic activity of Ti/de[B]SiO2 strongly depends on the content of B of support precursor, and the pretreatment temperature of the support. IR studies show that the sites in the deboronated silica xerogel to react with TiCl4 are not only the silanol nests, but also the defect sites produced during the deboronation. (C) 2001 Elsevier Science B.V. All rights reserved.