Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of t...Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of themembranes with special asymmetric structure. The preliminary results of gas permeation measurements indicated that the resultant hollow fiber membranes have the potential ability for oxygen/nitrogen separation.展开更多
Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), nb initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibratio...Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), nb initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of 4-methyl-3-penten-2-one. The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the functional vibrational modes.展开更多
3(R)-(t-Butyldiphenylsilyloxy)-1-penten-4-yne was prepared using D-xylose as the chiral template via an improved procedure for aldehyde-to-alkyne homologation in high yield.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 59833120).
文摘Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of themembranes with special asymmetric structure. The preliminary results of gas permeation measurements indicated that the resultant hollow fiber membranes have the potential ability for oxygen/nitrogen separation.
文摘Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), nb initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of 4-methyl-3-penten-2-one. The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the functional vibrational modes.
文摘3(R)-(t-Butyldiphenylsilyloxy)-1-penten-4-yne was prepared using D-xylose as the chiral template via an improved procedure for aldehyde-to-alkyne homologation in high yield.
