In the study of cyclohexane monoxygenation with PhIO catalyzed by TPPFe( Ⅲ )X, we found the Influence of different axial ionic ligands X (X = F, Cl, Br, I, SCN, OR, R, CH,3, C2H6, (CH3)2CH, (CH2)3C)in TPPFe( Ⅲ )X on...In the study of cyclohexane monoxygenation with PhIO catalyzed by TPPFe( Ⅲ )X, we found the Influence of different axial ionic ligands X (X = F, Cl, Br, I, SCN, OR, R, CH,3, C2H6, (CH3)2CH, (CH2)3C)in TPPFe( Ⅲ )X on the oxidation products distribution and the yields of cyclohexanol. This paper deals with the linear relationship between the catalytic activity of TPPFe(Ⅲ)X and both the electronic or/ and steric effects of the axial ligands OR in TPPFe(Ⅲ)OR on its catalytic activity.展开更多
CrAlVN coatings are of good intrinsic mechanical and tribological properties but lack of strength. Silicon can provide nitride coating high strength and excellent oxidation resistance. Logically, the combination of Cr...CrAlVN coatings are of good intrinsic mechanical and tribological properties but lack of strength. Silicon can provide nitride coating high strength and excellent oxidation resistance. Logically, the combination of CrAlVN and Si should provide a good candidate for dry machining. The effect of silicon content on CrAlSiVN coating＇s me- chanical, tribological properties and oxidation resistance was investigated. The coatings were deposited on cemented tungsten carbide and Si wafer （100） substrates in an in-line magnetron sputtering system. Grazing incidence X-ray diffractometer, scanning electron microscopy, atomic force microscopy, transmission electron microscopy, electron probe micro-analyzer, X-ray photoelectron spectroscopy and Auger electron spectroscopy were employed to characterize the microstructure and chemistry. Nanoindentation and ball-on-disc tribo-tester were used in characterization of the mechanical and tribological properties. Incorporating with silicon, the CrAlVN coating was strengthened （hard- ness： 21.2 GPa up to 38.7 GPa） ; even after 2 h exposure to 700 ℃ in air, the hardness still maintains at 11.0 GPa.展开更多
ObJective： To investigate the detrimental effects of hemorrhagic shock on the structure and function of mitochondria DNA （mtDNA） encoding cytochrome oxidase genes in intestinal epithelial cells. Methods ： Wistar ...ObJective： To investigate the detrimental effects of hemorrhagic shock on the structure and function of mitochondria DNA （mtDNA） encoding cytochrome oxidase genes in intestinal epithelial cells. Methods ： Wistar rats were used and divided into two groups： hemorrhagic shock group and control group. Hemorrhagic shock model of rats was utilized in this experiment. The mtDNA was extracted from the intestinal epithelial cells and amplified by polymerase chain reaction （ PCR ） with different primers of cytochrome oxidase （ COX Ⅰ, COX Ⅱ and COX Ⅲ）. The products of PCR were directly sequenced. Results ： Hemorrhagic shock could result in the point mutagenesis in mitochondrial genome encoding cytochrome oxidase （ COX I and COX II）. There were 4, 4, 22, 16, 35 point mutations in COX I from 5545 to 6838 bp in 5 shocked rats. There were five point mutations in COX II from 7191 to 7542 bp at the site of t7191c, t7212c, a7386g, a7483g, c7542g in 1 shocked rat. There was no mutation found in COX III. Conclusions： Hemorrhagic shock could significantly induce the damage of the gene of cytochrome oxidase encoded by mtDNA.展开更多
THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic perfor...THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic performances for the reaction have aroused much interest and argument.Kung et al. proposed that the active phase was magnesium orthovanadate （Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub>）, but Volta et al. suggested that magnesium pyrovanadate （α-Mg<sub>2</sub>V<sub>2</sub>O<sub>7</sub>） was the active phase; in this phase, V<sup>4+</sup> ions which are associated to the formation of oxygen vacancies could stably exist, and Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub> is responsible for the total oxidation due to nonexistence of V<sup>4+</sup> ions.展开更多
文摘In the study of cyclohexane monoxygenation with PhIO catalyzed by TPPFe( Ⅲ )X, we found the Influence of different axial ionic ligands X (X = F, Cl, Br, I, SCN, OR, R, CH,3, C2H6, (CH3)2CH, (CH2)3C)in TPPFe( Ⅲ )X on the oxidation products distribution and the yields of cyclohexanol. This paper deals with the linear relationship between the catalytic activity of TPPFe(Ⅲ)X and both the electronic or/ and steric effects of the axial ligands OR in TPPFe(Ⅲ)OR on its catalytic activity.
基金Item Sponsored by National Natural Science Foundation of China(51202035,51301041,51201056)Fundamental Research Funds for the Central Universities of China(CDJZR14135502)
文摘CrAlVN coatings are of good intrinsic mechanical and tribological properties but lack of strength. Silicon can provide nitride coating high strength and excellent oxidation resistance. Logically, the combination of CrAlVN and Si should provide a good candidate for dry machining. The effect of silicon content on CrAlSiVN coating＇s me- chanical, tribological properties and oxidation resistance was investigated. The coatings were deposited on cemented tungsten carbide and Si wafer （100） substrates in an in-line magnetron sputtering system. Grazing incidence X-ray diffractometer, scanning electron microscopy, atomic force microscopy, transmission electron microscopy, electron probe micro-analyzer, X-ray photoelectron spectroscopy and Auger electron spectroscopy were employed to characterize the microstructure and chemistry. Nanoindentation and ball-on-disc tribo-tester were used in characterization of the mechanical and tribological properties. Incorporating with silicon, the CrAlVN coating was strengthened （hard- ness： 21.2 GPa up to 38.7 GPa） ; even after 2 h exposure to 700 ℃ in air, the hardness still maintains at 11.0 GPa.
文摘ObJective： To investigate the detrimental effects of hemorrhagic shock on the structure and function of mitochondria DNA （mtDNA） encoding cytochrome oxidase genes in intestinal epithelial cells. Methods ： Wistar rats were used and divided into two groups： hemorrhagic shock group and control group. Hemorrhagic shock model of rats was utilized in this experiment. The mtDNA was extracted from the intestinal epithelial cells and amplified by polymerase chain reaction （ PCR ） with different primers of cytochrome oxidase （ COX Ⅰ, COX Ⅱ and COX Ⅲ）. The products of PCR were directly sequenced. Results ： Hemorrhagic shock could result in the point mutagenesis in mitochondrial genome encoding cytochrome oxidase （ COX I and COX II）. There were 4, 4, 22, 16, 35 point mutations in COX I from 5545 to 6838 bp in 5 shocked rats. There were five point mutations in COX II from 7191 to 7542 bp at the site of t7191c, t7212c, a7386g, a7483g, c7542g in 1 shocked rat. There was no mutation found in COX III. Conclusions： Hemorrhagic shock could significantly induce the damage of the gene of cytochrome oxidase encoded by mtDNA.
文摘THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic performances for the reaction have aroused much interest and argument.Kung et al. proposed that the active phase was magnesium orthovanadate （Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub>）, but Volta et al. suggested that magnesium pyrovanadate （α-Mg<sub>2</sub>V<sub>2</sub>O<sub>7</sub>） was the active phase; in this phase, V<sup>4+</sup> ions which are associated to the formation of oxygen vacancies could stably exist, and Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub> is responsible for the total oxidation due to nonexistence of V<sup>4+</sup> ions.
