A support(denoted AM) was prepared using pseudo-boehmite and mordenite.Ni-B and NiPtB amorphous catalysts were prepared on the support by the impregnation method followed by chemical reduction with a KBH4 solution.And...A support(denoted AM) was prepared using pseudo-boehmite and mordenite.Ni-B and NiPtB amorphous catalysts were prepared on the support by the impregnation method followed by chemical reduction with a KBH4 solution.And the catalysts were characterized by X-ray diffraction(XRD),environment scanning electron microscope(ESEM),inductively coupled plasma(ICP),H2-temperature programmed reduction(H2-TPR),differential thermal analysis(DTA),and BET.Benzene hydrogenation was used as a probe reaction to evaluate the effect of addition of small quantities of Pt on the NiB/AM catalyst.The results show that Pt can promote the reduction of NiO and the formation of active sites,leading to smaller catalyst particles and better dispersion of active metal particles on the support.The catalytic activity,sulfur resistance and thermal stability were remarkably improved by Pt doping of the NiB/AM catalyst.展开更多
cDNA of soybean mosaic virus (Beijing isolate, SMV-BJ) has been synthesized, using viralgenomic RNA as template and random hexanucleotides as primers. Based on the sequences of SMV-BJ coat protein (CP) gene as well as...cDNA of soybean mosaic virus (Beijing isolate, SMV-BJ) has been synthesized, using viralgenomic RNA as template and random hexanucleotides as primers. Based on the sequences of SMV-BJ coat protein (CP) gene as well as SMV- and WMV-II-related regions, oligonucleotides were made as primers for polymerase chain reaction (PCR). NIb gene of SMV-BJ was amplified by PCR, and cloned into pBluescript SK. The complete sequence was determined. The comparison of NIb genes between SMV-BJ and WMV-II . (USA) shows that similarities for nucleotide sequence reach 80.3%, and the deduced amino acid sequence. 91 3%. In consideration of the high identities in between the CP gene and the 3'-non-coding region between them, WMV-II might be considered as a watermelon strain of SMV Besides, some unexpected sequences were found in the 3'-region of 2 NIb gene clones. Following modification and splicing, a binary vector of NIb gene has been constructed for its expression in higher plant for the purpose of studying the possible replicase-mediated resistance in potyviruses.展开更多
Gas phase hydrogenation of benzene was selected as probe reaction to study the effects of heavy rare earth elements on the catalytic activity and sulfur resistance of amorphous NiB alloy. XRD, DSC, CO chemical adsorp...Gas phase hydrogenation of benzene was selected as probe reaction to study the effects of heavy rare earth elements on the catalytic activity and sulfur resistance of amorphous NiB alloy. XRD, DSC, CO chemical adsorption, TP5 and TPD were used to characterize the bulk and the surface properties of the alloys, respectively. The results indicate that the addition of a small amount of heavy rare earth (HRE) elements obviously improves the activity, thermal stability and sulfur resistance of amorphous NiB alloy. The HRE can alter H 2 adsorption bond strength, increase the surface area of active nickel and the number of active centers over the surface of NiB alloy and it also can decrease the activation energy of NiB alloy for benzene hydrogenation. There are four kinds of adsorbing sites over the surface of NiB and NiBRE, only three kinds of them have concerned with the reaction.展开更多
Nickel borides doped with transition metal (Cr, Mn, Fe, Co, Cu, and Zn) MNiB, 4% w/w respect to Ni were prepared by chemical reduction of nickel and metallic salts in methanol solution with borane-tetrahydrofurane (BH...Nickel borides doped with transition metal (Cr, Mn, Fe, Co, Cu, and Zn) MNiB, 4% w/w respect to Ni were prepared by chemical reduction of nickel and metallic salts in methanol solution with borane-tetrahydrofurane (BH<sub>3</sub>-THF) complex obtained in aprotic solvent (THF anhydrous). Different techniques were used to characterize these materials. The MNiB amorphous structure was verified by XRD. Thermal treatment in N<sub>2</sub> shows Ni°, Ni<sub>2</sub> Band NiO phases. Spongy-morphology was evident by SEM studies in all cases. XPS and TEM show that doped and non-doped nickel boride was present as Ni° in metallic state as principal phase and nickel alloying with boron was observed in minor quantities. The oxidation stability, magnetic susceptibility and catalytic effect are correlated with parameters of each dopant metal.展开更多
The NiB amorphous alloy catalysts supported on CNTs and alumina were prepared by impregnation and chemical reduction. The gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity...The NiB amorphous alloy catalysts supported on CNTs and alumina were prepared by impregnation and chemical reduction. The gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity. The result showed that the NiB amorphous alloy catalyst supported on carbon nanotubes exhibited higher activity than that supported on alumina.展开更多
The hydrogenation of aromatic ring and nitrobenzene over the amorphous nickel boron alloy has been investigated. The amorphous structure of the catalyst make itself exhibited a high catalytic activity in the hydrogena...The hydrogenation of aromatic ring and nitrobenzene over the amorphous nickel boron alloy has been investigated. The amorphous structure of the catalyst make itself exhibited a high catalytic activity in the hydrogenation of 4-ethylbenzoic acid, 4-pentylphenol and nitrobenzene. In the case of 4-pentylphenol and 4-ethylbenzoic acid, the hydrogenation conversions were 95%, 67% respectively, at 160 ℃ and hydrogen pressure of 6.0 MPa, while for nitrobenzene, the conversion was 100% at the same temperature under 4.0 MPa H 2.展开更多
The laser-induced fluorescence excitation spectra of jet-cooled NiB radicals have been recorded in the energy range of 19000-22100 cm-1. Eleven bands have been assigned to the [20.77]2П-X2∑＋ transition system for t...The laser-induced fluorescence excitation spectra of jet-cooled NiB radicals have been recorded in the energy range of 19000-22100 cm-1. Eleven bands have been assigned to the [20.77]2П-X2∑＋ transition system for the first time. The dispersed fluorescence spectra related to most of these bands have been investigated. Vibrationally excited levels of the ground electronic state, with v＂ up to 6, have been observed. In addition, the lifetimes for almost all the observed bands have also been measured.展开更多
The amorphous NiB alloy was prepared by chemical reduction and used in the hydrogenation of sulfolene to sulfolane.The used catalyst was treated by acid at different conditions.The catalyst was characterized by ICP, X...The amorphous NiB alloy was prepared by chemical reduction and used in the hydrogenation of sulfolene to sulfolane.The used catalyst was treated by acid at different conditions.The catalyst was characterized by ICP, XRD,TEM and SAED.The results shows that the oxide in the deactivated amorphous NiB alloy decreases obviously after the treating with acid(pH=2).The regenerated catalyst exhibits excellent catalytic activity and the amorphous structure is preserved.展开更多
基金Supported by the Overseas Scholars of Heilongjiang Province of China (1151hq006)
文摘A support(denoted AM) was prepared using pseudo-boehmite and mordenite.Ni-B and NiPtB amorphous catalysts were prepared on the support by the impregnation method followed by chemical reduction with a KBH4 solution.And the catalysts were characterized by X-ray diffraction(XRD),environment scanning electron microscope(ESEM),inductively coupled plasma(ICP),H2-temperature programmed reduction(H2-TPR),differential thermal analysis(DTA),and BET.Benzene hydrogenation was used as a probe reaction to evaluate the effect of addition of small quantities of Pt on the NiB/AM catalyst.The results show that Pt can promote the reduction of NiO and the formation of active sites,leading to smaller catalyst particles and better dispersion of active metal particles on the support.The catalytic activity,sulfur resistance and thermal stability were remarkably improved by Pt doping of the NiB/AM catalyst.
基金Project supported by the National Natural Science Foundation of China.
文摘cDNA of soybean mosaic virus (Beijing isolate, SMV-BJ) has been synthesized, using viralgenomic RNA as template and random hexanucleotides as primers. Based on the sequences of SMV-BJ coat protein (CP) gene as well as SMV- and WMV-II-related regions, oligonucleotides were made as primers for polymerase chain reaction (PCR). NIb gene of SMV-BJ was amplified by PCR, and cloned into pBluescript SK. The complete sequence was determined. The comparison of NIb genes between SMV-BJ and WMV-II . (USA) shows that similarities for nucleotide sequence reach 80.3%, and the deduced amino acid sequence. 91 3%. In consideration of the high identities in between the CP gene and the 3'-non-coding region between them, WMV-II might be considered as a watermelon strain of SMV Besides, some unexpected sequences were found in the 3'-region of 2 NIb gene clones. Following modification and splicing, a binary vector of NIb gene has been constructed for its expression in higher plant for the purpose of studying the possible replicase-mediated resistance in potyviruses.
文摘Gas phase hydrogenation of benzene was selected as probe reaction to study the effects of heavy rare earth elements on the catalytic activity and sulfur resistance of amorphous NiB alloy. XRD, DSC, CO chemical adsorption, TP5 and TPD were used to characterize the bulk and the surface properties of the alloys, respectively. The results indicate that the addition of a small amount of heavy rare earth (HRE) elements obviously improves the activity, thermal stability and sulfur resistance of amorphous NiB alloy. The HRE can alter H 2 adsorption bond strength, increase the surface area of active nickel and the number of active centers over the surface of NiB alloy and it also can decrease the activation energy of NiB alloy for benzene hydrogenation. There are four kinds of adsorbing sites over the surface of NiB and NiBRE, only three kinds of them have concerned with the reaction.
文摘Nickel borides doped with transition metal (Cr, Mn, Fe, Co, Cu, and Zn) MNiB, 4% w/w respect to Ni were prepared by chemical reduction of nickel and metallic salts in methanol solution with borane-tetrahydrofurane (BH<sub>3</sub>-THF) complex obtained in aprotic solvent (THF anhydrous). Different techniques were used to characterize these materials. The MNiB amorphous structure was verified by XRD. Thermal treatment in N<sub>2</sub> shows Ni°, Ni<sub>2</sub> Band NiO phases. Spongy-morphology was evident by SEM studies in all cases. XPS and TEM show that doped and non-doped nickel boride was present as Ni° in metallic state as principal phase and nickel alloying with boron was observed in minor quantities. The oxidation stability, magnetic susceptibility and catalytic effect are correlated with parameters of each dopant metal.
文摘The NiB amorphous alloy catalysts supported on CNTs and alumina were prepared by impregnation and chemical reduction. The gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity. The result showed that the NiB amorphous alloy catalyst supported on carbon nanotubes exhibited higher activity than that supported on alumina.
文摘The hydrogenation of aromatic ring and nitrobenzene over the amorphous nickel boron alloy has been investigated. The amorphous structure of the catalyst make itself exhibited a high catalytic activity in the hydrogenation of 4-ethylbenzoic acid, 4-pentylphenol and nitrobenzene. In the case of 4-pentylphenol and 4-ethylbenzoic acid, the hydrogenation conversions were 95%, 67% respectively, at 160 ℃ and hydrogen pressure of 6.0 MPa, while for nitrobenzene, the conversion was 100% at the same temperature under 4.0 MPa H 2.
文摘The laser-induced fluorescence excitation spectra of jet-cooled NiB radicals have been recorded in the energy range of 19000-22100 cm-1. Eleven bands have been assigned to the [20.77]2П-X2∑＋ transition system for the first time. The dispersed fluorescence spectra related to most of these bands have been investigated. Vibrationally excited levels of the ground electronic state, with v＂ up to 6, have been observed. In addition, the lifetimes for almost all the observed bands have also been measured.
文摘The amorphous NiB alloy was prepared by chemical reduction and used in the hydrogenation of sulfolene to sulfolane.The used catalyst was treated by acid at different conditions.The catalyst was characterized by ICP, XRD,TEM and SAED.The results shows that the oxide in the deactivated amorphous NiB alloy decreases obviously after the treating with acid(pH=2).The regenerated catalyst exhibits excellent catalytic activity and the amorphous structure is preserved.
