This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothermal fluids. Experiments prove that Au and Cu can re-distribute in vapor phase and liquid phase during separation of Au- and Cu-bearin...This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothermal fluids. Experiments prove that Au and Cu can re-distribute in vapor phase and liquid phase during separation of Au- and Cu-bearing supercritical fluids to vapor and liquid phases. These experimental results can illustrate some ore geneses, where boiling phenomena of ore fluids were found. Au- and Cubearing NaHCO3-HCl solutions were heated up to more than 350℃ in the main vessel, and then passed through a phase separator in a temperature range from 250℃ to 300℃, separated into vapor and liquid phases. We collected and analyzed the liquid and vapor samples separately, and found that Au and Cu dissolved and distributed in vapor phase. In some cases, the concentrations of Au and Cu in vapor are higher than those in liquid phase. Those experiments are used to interpret field observations of fluid inclusion data of some Au and Cu deposits, and demonstrate that some Au and Cu ore deposits are derived from metals transportation in vapor phase.展开更多
MnSAPO-34 molecular sieves were synthesized by vapor-phase transport(VPT) method using triethylamine(Et3N) as a structure directing agent(SDA),and were characterized by XRD,BET,SEM,UV-Vis,FT-IR,and TG analyses.The inf...MnSAPO-34 molecular sieves were synthesized by vapor-phase transport(VPT) method using triethylamine(Et3N) as a structure directing agent(SDA),and were characterized by XRD,BET,SEM,UV-Vis,FT-IR,and TG analyses.The influence of the zeolite crystallization conditions and the dry-gel composition were investigated.The results showed that the synthesis conditions had an effect on the crystalline phase.Pure MnSAPO-34 had been obtained when it was crystallized at 140℃ for 18 hours.The ratio of MnO/Al2O3 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology.Beyond this scope,MnSAPO-5 with an AFI topology structure was obtained as an impurity substance.UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve.The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of 1,2-propanediol with cyclohexanone.High yield of cyclohexanone-1,2-propanediol ketal was obtained.展开更多
In this paper we investigated the optical properties of ZnO and Mn doped ZnO nanocrystals that were fabricated by a vapor phase transport growth process, using zinc acetate dihydrate with or without Mn in a constant O...In this paper we investigated the optical properties of ZnO and Mn doped ZnO nanocrystals that were fabricated by a vapor phase transport growth process, using zinc acetate dihydrate with or without Mn in a constant O2/Ar mixture gas flowing through the furnace at 400600℃, respectively. The as grown ZnO nanocrystals are homogeneous with a mean size of 19 nm observed by scanning electron microscope（SEM）. The optical characteristics were analyzed by absorption spectra and photoluminescence（PL） spectra at room-temperature. For ZnO nanocrystals, a strong and predominant UV emission peaked at 377 nm was found in the PL spectra. For Mn doped ZnO nanocrystals, in addition to the strong UV emission, a strong blue emission peaked at 435 nm was observed as well. By doping Mn ions, the major UV emission shifts from 377 nm to 408 nm, showing that Mn ions were not only incorporated into ZnO Ncs, but also introduced an impurity level in the bandgap. Moreover, with the concentration of Mn increasing, the relative intensities of the two emissions change largely, and the photoluminescence mechanism of them is discussed.展开更多
ZnO particles were prepared by Au-catalyzed vapor phase transport method on silicon substrate. Scanning electron microscopy（SEM） images show many ZnO particles were formed on the sample surface. They grew up layer b...ZnO particles were prepared by Au-catalyzed vapor phase transport method on silicon substrate. Scanning electron microscopy（SEM） images show many ZnO particles were formed on the sample surface. They grew up layer by layer along the c-axis, which was confirmed by the results of X-ray diffraction（XRD）. The morphology of ZnO particles is close to hemisphere and its formation process could be seen from the SEM image. The room temperature photoluminescence（PL） measurement revealed a narrow UV emission peak at 3.27 eV and a broad green emission peak at 2.45 eV, which was caused by the near-band-edge and deep-level emissions.展开更多
文摘This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothermal fluids. Experiments prove that Au and Cu can re-distribute in vapor phase and liquid phase during separation of Au- and Cu-bearing supercritical fluids to vapor and liquid phases. These experimental results can illustrate some ore geneses, where boiling phenomena of ore fluids were found. Au- and Cubearing NaHCO3-HCl solutions were heated up to more than 350℃ in the main vessel, and then passed through a phase separator in a temperature range from 250℃ to 300℃, separated into vapor and liquid phases. We collected and analyzed the liquid and vapor samples separately, and found that Au and Cu dissolved and distributed in vapor phase. In some cases, the concentrations of Au and Cu in vapor are higher than those in liquid phase. Those experiments are used to interpret field observations of fluid inclusion data of some Au and Cu deposits, and demonstrate that some Au and Cu ore deposits are derived from metals transportation in vapor phase.
基金supported by the Key Laboratory of Fine Chemicals,Jiangsu Provincefinancially supported by the Jiangsu Province Science and Technology Support Program (BE2011651)the Key University Science Research Project of Jiangsu Province (11KJA610002)
文摘MnSAPO-34 molecular sieves were synthesized by vapor-phase transport(VPT) method using triethylamine(Et3N) as a structure directing agent(SDA),and were characterized by XRD,BET,SEM,UV-Vis,FT-IR,and TG analyses.The influence of the zeolite crystallization conditions and the dry-gel composition were investigated.The results showed that the synthesis conditions had an effect on the crystalline phase.Pure MnSAPO-34 had been obtained when it was crystallized at 140℃ for 18 hours.The ratio of MnO/Al2O3 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology.Beyond this scope,MnSAPO-5 with an AFI topology structure was obtained as an impurity substance.UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve.The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of 1,2-propanediol with cyclohexanone.High yield of cyclohexanone-1,2-propanediol ketal was obtained.
基金supported in parts by the National Natural Science Foundation of China(No.60776004,60976071)the Laboratory for Thin Film Microfabrication of the Ministry of Education
文摘In this paper we investigated the optical properties of ZnO and Mn doped ZnO nanocrystals that were fabricated by a vapor phase transport growth process, using zinc acetate dihydrate with or without Mn in a constant O2/Ar mixture gas flowing through the furnace at 400600℃, respectively. The as grown ZnO nanocrystals are homogeneous with a mean size of 19 nm observed by scanning electron microscope（SEM）. The optical characteristics were analyzed by absorption spectra and photoluminescence（PL） spectra at room-temperature. For ZnO nanocrystals, a strong and predominant UV emission peaked at 377 nm was found in the PL spectra. For Mn doped ZnO nanocrystals, in addition to the strong UV emission, a strong blue emission peaked at 435 nm was observed as well. By doping Mn ions, the major UV emission shifts from 377 nm to 408 nm, showing that Mn ions were not only incorporated into ZnO Ncs, but also introduced an impurity level in the bandgap. Moreover, with the concentration of Mn increasing, the relative intensities of the two emissions change largely, and the photoluminescence mechanism of them is discussed.
基金Supported by the National Natural Science Foundation of China(Nos.20631010 and 90922034)the Graduate Innovation Fund of "985" Program of Jilin University, China
文摘ZnO particles were prepared by Au-catalyzed vapor phase transport method on silicon substrate. Scanning electron microscopy（SEM） images show many ZnO particles were formed on the sample surface. They grew up layer by layer along the c-axis, which was confirmed by the results of X-ray diffraction（XRD）. The morphology of ZnO particles is close to hemisphere and its formation process could be seen from the SEM image. The room temperature photoluminescence（PL） measurement revealed a narrow UV emission peak at 3.27 eV and a broad green emission peak at 2.45 eV, which was caused by the near-band-edge and deep-level emissions.
