Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sam...Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.展开更多
Glass microchips with different structures and functions were fabricated in our laboratory.The basic characteristic of the home-made microchips was evaluated,such as the quality of the etched microchannels,reproducibi...Glass microchips with different structures and functions were fabricated in our laboratory.The basic characteristic of the home-made microchips was evaluated,such as the quality of the etched microchannels,reproducibility of electrophoretic separation,and life time etc..The migration time RSD for Rhodamine B in the same or different microchannels were 2.31% or 2.44%,respectively.The column efficiency in the same glass microchip didn′t declined obviously until 200 consecutive running.Compared to the glass microchip made by Micralyne,the similar separation results were obtained on both kinds of microchips.Since,the cost of the home-made glass microchips is much lower, our home-made glass microchips show a great advantage(over) the commercial microchips in terms of the performance to cost.展开更多
The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using ...The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.展开更多
Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. Fo...Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. For cluster ion MnxOy with x >5, the mean valences of Mn atom in cluster MnxOy, ions is 2.4±0.1, and is almost unchangeable with the size of cluster from x=5-25. The relative intensity of the observed peaks with the same x but different y, can be well fitted by a binomial distribution, for x= 5-12 clusters. All the observed information indicate a gas-phase MnO, MnO2 molecule aggregation mechanism for the production of these oxygen-rich cluster ions.展开更多
The multiphoton ionization and fragmentation pathway of furan at 450nm is analyzed on the basis of statistical theory and Ladder-Switching model. Our calculation indicates that fragmentation takes plase after furan mo...The multiphoton ionization and fragmentation pathway of furan at 450nm is analyzed on the basis of statistical theory and Ladder-Switching model. Our calculation indicates that fragmentation takes plase after furan molecules absorb six photons of 450nm, C+ begins to appear after absorption of nine photons, production of C2+ ions needs absorption of at least 15 photons. Our interesting result is that C+ ions is produced by dissociation of C3H+, CH2+ and C3+ ions, not of C2+ ions. Theoretically computed relative abundance of C+/C2+ after absorption 15 photons agrees well with our experimental results.展开更多
文摘Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.
文摘Glass microchips with different structures and functions were fabricated in our laboratory.The basic characteristic of the home-made microchips was evaluated,such as the quality of the etched microchannels,reproducibility of electrophoretic separation,and life time etc..The migration time RSD for Rhodamine B in the same or different microchannels were 2.31% or 2.44%,respectively.The column efficiency in the same glass microchip didn′t declined obviously until 200 consecutive running.Compared to the glass microchip made by Micralyne,the similar separation results were obtained on both kinds of microchips.Since,the cost of the home-made glass microchips is much lower, our home-made glass microchips show a great advantage(over) the commercial microchips in terms of the performance to cost.
文摘The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.
文摘Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. For cluster ion MnxOy with x >5, the mean valences of Mn atom in cluster MnxOy, ions is 2.4±0.1, and is almost unchangeable with the size of cluster from x=5-25. The relative intensity of the observed peaks with the same x but different y, can be well fitted by a binomial distribution, for x= 5-12 clusters. All the observed information indicate a gas-phase MnO, MnO2 molecule aggregation mechanism for the production of these oxygen-rich cluster ions.
文摘The multiphoton ionization and fragmentation pathway of furan at 450nm is analyzed on the basis of statistical theory and Ladder-Switching model. Our calculation indicates that fragmentation takes plase after furan molecules absorb six photons of 450nm, C+ begins to appear after absorption of nine photons, production of C2+ ions needs absorption of at least 15 photons. Our interesting result is that C+ ions is produced by dissociation of C3H+, CH2+ and C3+ ions, not of C2+ ions. Theoretically computed relative abundance of C+/C2+ after absorption 15 photons agrees well with our experimental results.
