Diamond films have been synthesized by means of LCVD through combined effects of a XeCl ultraviolet laser and an infrared CO2 laser. A special apparatus has been developed. The conditions of synthesis and the roles pl...Diamond films have been synthesized by means of LCVD through combined effects of a XeCl ultraviolet laser and an infrared CO2 laser. A special apparatus has been developed. The conditions of synthesis and the roles played by both lasers were studied. High-purity diamond films were deposited on Si substrates at 340 degrees C.展开更多
Further phytochemical investigation of the roots of Ligularia nelumbi folia afforded six new sinapyl alcohol derivatives. Their structures were elucidated by high field NMR spectroscopy.
Phytochemical re-investigation of the anti-leukemia plant Laggera pterodonta afford four new eudemsanes (1-4) and six new eudesmanoic glucosides (5-10), Their structures were elucidated by high field 1D and 2D NMR tec...Phytochemical re-investigation of the anti-leukemia plant Laggera pterodonta afford four new eudemsanes (1-4) and six new eudesmanoic glucosides (5-10), Their structures were elucidated by high field 1D and 2D NMR techniques and chemical methods.展开更多
Ceratoside A (1), a new compound was isolated from the butanol-soluble fraction of Ceratostigma willmottianum, Its structure was determined by the utilization of 2D-NMR techniques.
The evolution of single elliptic vortex rings for initial aspect ratio (AR) = 2,4,6 has been studied. The incompressible Navier-Stokes equations are solved by a dealiased pseudo-spectral method with 64(3) grid points ...The evolution of single elliptic vortex rings for initial aspect ratio (AR) = 2,4,6 has been studied. The incompressible Navier-Stokes equations are solved by a dealiased pseudo-spectral method with 64(3) grid points in a periodic cube. We find that there are three kinds of vortex motion as AR increases and bifurcation occurs at certain AR. The processes of advection, interaction and decay of vortex ring are discussed. Numerical results coincide with experiments and other authors' numerical simulation.展开更多
A new guaiane sesquiterpene was isolated from Ligularia Nelumbifolia. Its structure was elucidated by spectroscopic methods including 2D-NMR techniques and showed to be 4 alpha ,9 alpha ,10 beta -tri-acetoxy-1 beta, 5...A new guaiane sesquiterpene was isolated from Ligularia Nelumbifolia. Its structure was elucidated by spectroscopic methods including 2D-NMR techniques and showed to be 4 alpha ,9 alpha ,10 beta -tri-acetoxy-1 beta, 5 alpha- guaia-6-ene (1).展开更多
IN photodynamic therapy, the damage of protein results from the photooxidation of one ormore of only five amino acid residues (tryptophanyl, tyrosyl, histidyl, methionyl and cys-teinyl). These five amino acids are als...IN photodynamic therapy, the damage of protein results from the photooxidation of one ormore of only five amino acid residues (tryptophanyl, tyrosyl, histidyl, methionyl and cys-teinyl). These five amino acids are also readily photooxidized in their monomeric states. How-ever, the reaction kinetics and mechanisms of free amino acids and bound amino acid residuesin proteins are somewhat different. For example, Tassin found that the incorporation of tryp-tophan into a peptide linkage dramatically altered its susceptibility to photooxidation as well展开更多
DURING the 1993’s expedition to the northern Fildes Peninsula of the King George Island,Antarctica, dark grey fine-sand and sub-clay sediments were found in the Xishi Gully, 250
文摘Diamond films have been synthesized by means of LCVD through combined effects of a XeCl ultraviolet laser and an infrared CO2 laser. A special apparatus has been developed. The conditions of synthesis and the roles played by both lasers were studied. High-purity diamond films were deposited on Si substrates at 340 degrees C.
文摘Further phytochemical investigation of the roots of Ligularia nelumbi folia afforded six new sinapyl alcohol derivatives. Their structures were elucidated by high field NMR spectroscopy.
文摘Phytochemical re-investigation of the anti-leukemia plant Laggera pterodonta afford four new eudemsanes (1-4) and six new eudesmanoic glucosides (5-10), Their structures were elucidated by high field 1D and 2D NMR techniques and chemical methods.
文摘Ceratoside A (1), a new compound was isolated from the butanol-soluble fraction of Ceratostigma willmottianum, Its structure was determined by the utilization of 2D-NMR techniques.
基金The project is supported by National Natural Science Foundation of China and Doctoral Program of Institution of Higher Education
文摘The evolution of single elliptic vortex rings for initial aspect ratio (AR) = 2,4,6 has been studied. The incompressible Navier-Stokes equations are solved by a dealiased pseudo-spectral method with 64(3) grid points in a periodic cube. We find that there are three kinds of vortex motion as AR increases and bifurcation occurs at certain AR. The processes of advection, interaction and decay of vortex ring are discussed. Numerical results coincide with experiments and other authors' numerical simulation.
文摘A new guaiane sesquiterpene was isolated from Ligularia Nelumbifolia. Its structure was elucidated by spectroscopic methods including 2D-NMR techniques and showed to be 4 alpha ,9 alpha ,10 beta -tri-acetoxy-1 beta, 5 alpha- guaia-6-ene (1).
文摘IN photodynamic therapy, the damage of protein results from the photooxidation of one ormore of only five amino acid residues (tryptophanyl, tyrosyl, histidyl, methionyl and cys-teinyl). These five amino acids are also readily photooxidized in their monomeric states. How-ever, the reaction kinetics and mechanisms of free amino acids and bound amino acid residuesin proteins are somewhat different. For example, Tassin found that the incorporation of tryp-tophan into a peptide linkage dramatically altered its susceptibility to photooxidation as well
文摘DURING the 1993’s expedition to the northern Fildes Peninsula of the King George Island,Antarctica, dark grey fine-sand and sub-clay sediments were found in the Xishi Gully, 250
