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
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
In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At t...In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At the variation range of the collision energies, the excitation functions can be taken asaR(ET) De In(1 + QMAX/ET)"where ET and QMAX are the coilision energy and the reaction exoergic energy, respectively,and n is a parameter which is correlative to the Illnner of the active vibrational modes in radical R during the reaction processes. Tab1e 2 gives the paramters of the excitation fUllctions for these reactions.展开更多
Magic number cluster ion Mn5+ and abundant Mn/O cluster ions havc been formed by 532nm laser ablation of MnCO3 solid sample with time-of-flight mass spectroscopy detection. The experimental results show that Mn5+ was ...Magic number cluster ion Mn5+ and abundant Mn/O cluster ions havc been formed by 532nm laser ablation of MnCO3 solid sample with time-of-flight mass spectroscopy detection. The experimental results show that Mn5+ was formed in the cooler dilute tail region of the plume produced by laser ablation, while Mn/O cluster ions were mainly formed in the hotter dense preceding portion of the plume, they all were produced by postablation cluster growth in the ablation plume. Pentagonal with D(5h) symmetry is the possible structure of Mn5+, which is supported by our ab initio calculation.展开更多
We investigate high-order harmonic generations by controlling various quantum paths of harmonics in an infrared laser field which combines a low-frequency pulse. Both classical theory and the quantum wavelet transform...We investigate high-order harmonic generations by controlling various quantum paths of harmonics in an infrared laser field which combines a low-frequency pulse. Both classical theory and the quantum wavelet transform method are used to understand the physics of harmonics. By adjusting the carrier envelope phase of the fundamental field, the intensities of harmonic spectra increase and the harmonics in the plateau become regular. Attosecond pulses each with a duration of 58 as are obtained directly by compressing the harmonics, and with phase compensation an isolated attosecond pulse less than 30 as can be generated.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In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At the variation range of the collision energies, the excitation functions can be taken asaR(ET) De In(1 + QMAX/ET)"where ET and QMAX are the coilision energy and the reaction exoergic energy, respectively,and n is a parameter which is correlative to the Illnner of the active vibrational modes in radical R during the reaction processes. Tab1e 2 gives the paramters of the excitation fUllctions for these reactions.
文摘Magic number cluster ion Mn5+ and abundant Mn/O cluster ions havc been formed by 532nm laser ablation of MnCO3 solid sample with time-of-flight mass spectroscopy detection. The experimental results show that Mn5+ was formed in the cooler dilute tail region of the plume produced by laser ablation, while Mn/O cluster ions were mainly formed in the hotter dense preceding portion of the plume, they all were produced by postablation cluster growth in the ablation plume. Pentagonal with D(5h) symmetry is the possible structure of Mn5+, which is supported by our ab initio calculation.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974198)
文摘We investigate high-order harmonic generations by controlling various quantum paths of harmonics in an infrared laser field which combines a low-frequency pulse. Both classical theory and the quantum wavelet transform method are used to understand the physics of harmonics. By adjusting the carrier envelope phase of the fundamental field, the intensities of harmonic spectra increase and the harmonics in the plateau become regular. Attosecond pulses each with a duration of 58 as are obtained directly by compressing the harmonics, and with phase compensation an isolated attosecond pulse less than 30 as can be generated.
