The aim of this study was to investigate the structural composition of lignin (LIPE®) extracted from Eucalyptus grandis, before and after exposure to the gastrointestinal tract of ruminants. For this study lig...The aim of this study was to investigate the structural composition of lignin (LIPE®) extracted from Eucalyptus grandis, before and after exposure to the gastrointestinal tract of ruminants. For this study lignin was isolated, purified and characterized using <sup>1</sup>H and <sup>13</sup>C Nuclear Magnetic Resonance Spectroscopy, nitrobenzene oxidation, functional groups analysis and gas chromatography with mass spectroscopy. To have a better understanding of lignin morphology and of its ultra structure, electron microscopy in wood cell wall was utilized. The lignin fecal samples showed similar <sup>1</sup>H NMR spectrums and nitrobenzene oxidation products compared with LIPE®. The result of the microanalysis of LIPE®was similar to data shown in the literature. The ultra structure of lignin was similar to that of Bamboo (hard wood). The lignin isolated from feces of sheep was identical to the original LIPE®, which means that this product can be used as an external marker in protein digestibility in sheep.展开更多
A series of mesoporous nanocrystalline silicoaluminophosphate (SAPO)zeolites (SAPO-34)were synthesized via an ultrasonic and microwave-assisted hydrothermal method in the presence of [3- (trimethoxysilyl)propyl]octade...A series of mesoporous nanocrystalline silicoaluminophosphate (SAPO)zeolites (SAPO-34)were synthesized via an ultrasonic and microwave-assisted hydrothermal method in the presence of [3- (trimethoxysilyl)propyl]octadecyldimethylammonium chloride and cetyltrimethylammonium bromide surfactants as soft templates.Nickel and cerium were then doped on SAPO-34using incorporation and impregnation methods,and all the catalysts were applied to the methanol-to-olefin (MTO)reaction. The catalysts were characterized using X-ray diffraction,field-emission scanning electron microcopy, inductively coupled plasma-atomic emission spectroscopy,transmission electron microscopy,Fourier- transform infrared spectroscopy,Brunauer-Emmett-Teller analysis,NH3temperature-programmed desorption analysis,and thermogravimetric analysis.For the impregnation method,the effect of using protic or aprotic solvents as impregnation media on the physico-chemical properties of the metal-based SAPO-34was investigated.Water and N,N-dimethylformamide (DMF)were employed as the protic and aprotic solvents,respectively.The catalyst prepared using the aprotic DMF solvent exhibited higher dispersion and lower aggregation of metal species compared with that prepared using the protic water solvent.Furthermore,the sample synthesized using the incorporation method exhibited good catalytic performance;however,the Ni-Ce[SAPO-34 sample prepared using the impregnation method and aprotic DMF solvent exhibited superior catalytic performance in the MTO reaction.展开更多
文摘The aim of this study was to investigate the structural composition of lignin (LIPE®) extracted from Eucalyptus grandis, before and after exposure to the gastrointestinal tract of ruminants. For this study lignin was isolated, purified and characterized using <sup>1</sup>H and <sup>13</sup>C Nuclear Magnetic Resonance Spectroscopy, nitrobenzene oxidation, functional groups analysis and gas chromatography with mass spectroscopy. To have a better understanding of lignin morphology and of its ultra structure, electron microscopy in wood cell wall was utilized. The lignin fecal samples showed similar <sup>1</sup>H NMR spectrums and nitrobenzene oxidation products compared with LIPE®. The result of the microanalysis of LIPE®was similar to data shown in the literature. The ultra structure of lignin was similar to that of Bamboo (hard wood). The lignin isolated from feces of sheep was identical to the original LIPE®, which means that this product can be used as an external marker in protein digestibility in sheep.
文摘A series of mesoporous nanocrystalline silicoaluminophosphate (SAPO)zeolites (SAPO-34)were synthesized via an ultrasonic and microwave-assisted hydrothermal method in the presence of [3- (trimethoxysilyl)propyl]octadecyldimethylammonium chloride and cetyltrimethylammonium bromide surfactants as soft templates.Nickel and cerium were then doped on SAPO-34using incorporation and impregnation methods,and all the catalysts were applied to the methanol-to-olefin (MTO)reaction. The catalysts were characterized using X-ray diffraction,field-emission scanning electron microcopy, inductively coupled plasma-atomic emission spectroscopy,transmission electron microscopy,Fourier- transform infrared spectroscopy,Brunauer-Emmett-Teller analysis,NH3temperature-programmed desorption analysis,and thermogravimetric analysis.For the impregnation method,the effect of using protic or aprotic solvents as impregnation media on the physico-chemical properties of the metal-based SAPO-34was investigated.Water and N,N-dimethylformamide (DMF)were employed as the protic and aprotic solvents,respectively.The catalyst prepared using the aprotic DMF solvent exhibited higher dispersion and lower aggregation of metal species compared with that prepared using the protic water solvent.Furthermore,the sample synthesized using the incorporation method exhibited good catalytic performance;however,the Ni-Ce[SAPO-34 sample prepared using the impregnation method and aprotic DMF solvent exhibited superior catalytic performance in the MTO reaction.
