In order to provide detailed information about Cd structure and gain more insight regarding ionization degrees and types of transition,as well as the understanding of the temporal evolution behavior of laser produced ...In order to provide detailed information about Cd structure and gain more insight regarding ionization degrees and types of transition,as well as the understanding of the temporal evolution behavior of laser produced Cd plasmas,extreme ultraviolet spectra of laser-produced cadmium(Cd)plasmas have been measured in the 8.4-12 nm region using spatiotemporally resolved laser-produced plasma spectroscopy technique.Spectral features were analyzed by the Hartree-Fock(HF)method with relativistic correlations(HFR)using the Cowan code.The results showed that the 4p-5s resonance transition arrays from Cd^9+to Cd^13+merged to form intense lines in this spectral region.A number of new spectral features from Cd^9+and Cd^10+ions are reported in this study.Based on the assumption of a normalized Boltzmann distribution among the excited states associated with a steady-state collisional-radiative model,the plasma parameters were obtained by comparing the experimental and simulated spectra.As a result,we succeeded in reproducing the synthetic spectra for different time delays,which yielded good agreement with the experiments.The temporal evolution behaviors of electron temperature and electron density of plasma were also analyzed.展开更多
SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO dep...SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO depress-ing mechanism i this paper describes studying results on the ef-fect of dissolved ions on SCO depressing property using ul-traviolet absorption spectra. It is found that the effect of dis-solved ions, especially Mg2+ ?on the SCO adsorption property is strong. When Mg2+ concentration is low,dolomite adsorbs SCO and is depressed. When Mgz+ concentration is more than 90g/t in pulp.SCO adsorption capacity on colophane is obvi-ously greater than that on dolomite,which results in the de-pression of collophane. The adsorption results are consistent with flotation results.展开更多
The energy band structure with type-I alignment at the PbTe/CdTe（111） heterojunction interface is determined by the ultraviolet photoelectron spectrum using synchrotron radiation. The valence band and conduction ban...The energy band structure with type-I alignment at the PbTe/CdTe（111） heterojunction interface is determined by the ultraviolet photoelectron spectrum using synchrotron radiation. The valence band and conduction band offsets are obtained to be 0.09±0.12 and 1.19±0.12 eV, respectively. These results are in agreement with theoretically predicted ones. The accurate determination of the valence band and conduction band offsets is useful for the fundamental understanding of the mid-infrared light emission from the PbTe/CdTe heterostructures and its application in devices.展开更多
Blood plays an important role in the clinical di-agnosis and treatment, the analysis of blood will be of very important practical significance. The experiment shows that the absorption spectra of blood are of serious ...Blood plays an important role in the clinical di-agnosis and treatment, the analysis of blood will be of very important practical significance. The experiment shows that the absorption spectra of blood are of serious noise in the wave band of 200 to 300 nm, which hides the useful spectral characteristics. The effective separation of the noise was achieved by db4 wavelet transform, and the signals of reconstruction have been obviously improved in the noise serious wave band, reflecting some useful information. The absorption peaks of different samples are displaced to some degrees. The correlation between absorbance at 278nm and blood fat concentration is no significant and random. Based on the evident correlation between serum absorption spectrum and blood fat con-centration in the wave band of 265 to 282nm, a neural network model was built to forecast the blood fat concentration, bringing a relatively good prediction. This provides a new spectral test method of blood fat concentration.展开更多
We propose a scheme to generate isolated attosecond pulses in the water-window spectral region. Based on the numerical solutions of the single active electron model, we investigate high-order harmonic generation in he...We propose a scheme to generate isolated attosecond pulses in the water-window spectral region. Based on the numerical solutions of the single active electron model, we investigate high-order harmonic generation in helium atoms driven by a multi-cycle two-colour optical field synthesized by an intense 2000 nm, 20 fs pulse and its frequency-doubled pulse. When the latter is slightly detuned and properly phase shifted with respect to the fundamental laser pulse, an ultra-broad extreme ultraviolet supercontinuum with a spectral width of 130 eV can be generated in the 270 400 eV spectral regions. A supercontinuum from 280-340 eV in the water window can be selected to yield an isolated 67 attosecond pulse without employing any phase compensation. This water window coherent x-ray pulse with less than 100 attosecond duration is a potential tool for studying the ultrafast electronic dynamics of biological samples in water.展开更多
Extreme ultraviolet(EUV)source produced by laser-induced discharge plasma(LDP)is a potential technical means in inspection and metrology.A pulsed Nd:YAG laser is focused on a tin plate to produce an initial plasma the...Extreme ultraviolet(EUV)source produced by laser-induced discharge plasma(LDP)is a potential technical means in inspection and metrology.A pulsed Nd:YAG laser is focused on a tin plate to produce an initial plasma thereby triggering a discharge between high-voltage electrodes in a vacuum system.The process of micro-pinch formation during the current rising is recorded by a time-resolved intensified charge couple device camera.The evolution of electron temperature and density of LDP are obtained by optical emission spectrometry.An extreme ultraviolet spectrometer is built up to investigate the EUV spectrum of Sn LDP at 13.5 nm.The laser and discharge parameters such as laser energy,voltage,gap distance,and anode shape can influence the EUV emission.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0402300)the National Natural Science Foundation of China(Grant Nos.11874051,11904293,and 61965015)the Special Fund Project for Guiding Scientific and Technological Innovation of Gansu Province,China(Grant No.2019zx-10).
文摘In order to provide detailed information about Cd structure and gain more insight regarding ionization degrees and types of transition,as well as the understanding of the temporal evolution behavior of laser produced Cd plasmas,extreme ultraviolet spectra of laser-produced cadmium(Cd)plasmas have been measured in the 8.4-12 nm region using spatiotemporally resolved laser-produced plasma spectroscopy technique.Spectral features were analyzed by the Hartree-Fock(HF)method with relativistic correlations(HFR)using the Cowan code.The results showed that the 4p-5s resonance transition arrays from Cd^9+to Cd^13+merged to form intense lines in this spectral region.A number of new spectral features from Cd^9+and Cd^10+ions are reported in this study.Based on the assumption of a normalized Boltzmann distribution among the excited states associated with a steady-state collisional-radiative model,the plasma parameters were obtained by comparing the experimental and simulated spectra.As a result,we succeeded in reproducing the synthetic spectra for different time delays,which yielded good agreement with the experiments.The temporal evolution behaviors of electron temperature and electron density of plasma were also analyzed.
文摘SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO depress-ing mechanism i this paper describes studying results on the ef-fect of dissolved ions on SCO depressing property using ul-traviolet absorption spectra. It is found that the effect of dis-solved ions, especially Mg2+ ?on the SCO adsorption property is strong. When Mg2+ concentration is low,dolomite adsorbs SCO and is depressed. When Mgz+ concentration is more than 90g/t in pulp.SCO adsorption capacity on colophane is obvi-ously greater than that on dolomite,which results in the de-pression of collophane. The adsorption results are consistent with flotation results.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10974174 and 60676003)
文摘The energy band structure with type-I alignment at the PbTe/CdTe（111） heterojunction interface is determined by the ultraviolet photoelectron spectrum using synchrotron radiation. The valence band and conduction band offsets are obtained to be 0.09±0.12 and 1.19±0.12 eV, respectively. These results are in agreement with theoretically predicted ones. The accurate determination of the valence band and conduction band offsets is useful for the fundamental understanding of the mid-infrared light emission from the PbTe/CdTe heterostructures and its application in devices.
文摘Blood plays an important role in the clinical di-agnosis and treatment, the analysis of blood will be of very important practical significance. The experiment shows that the absorption spectra of blood are of serious noise in the wave band of 200 to 300 nm, which hides the useful spectral characteristics. The effective separation of the noise was achieved by db4 wavelet transform, and the signals of reconstruction have been obviously improved in the noise serious wave band, reflecting some useful information. The absorption peaks of different samples are displaced to some degrees. The correlation between absorbance at 278nm and blood fat concentration is no significant and random. Based on the evident correlation between serum absorption spectrum and blood fat con-centration in the wave band of 265 to 282nm, a neural network model was built to forecast the blood fat concentration, bringing a relatively good prediction. This provides a new spectral test method of blood fat concentration.
基金Project supported by the National Basic Research Program of China (Grant No. 2006CB806000)the Knowledge Innovation Program of Chinese Academy of Sciencesthe National Natural Science Foundation of China (Grant Nos. 10734080, 60578049 and 10523003)
文摘We propose a scheme to generate isolated attosecond pulses in the water-window spectral region. Based on the numerical solutions of the single active electron model, we investigate high-order harmonic generation in helium atoms driven by a multi-cycle two-colour optical field synthesized by an intense 2000 nm, 20 fs pulse and its frequency-doubled pulse. When the latter is slightly detuned and properly phase shifted with respect to the fundamental laser pulse, an ultra-broad extreme ultraviolet supercontinuum with a spectral width of 130 eV can be generated in the 270 400 eV spectral regions. A supercontinuum from 280-340 eV in the water window can be selected to yield an isolated 67 attosecond pulse without employing any phase compensation. This water window coherent x-ray pulse with less than 100 attosecond duration is a potential tool for studying the ultrafast electronic dynamics of biological samples in water.
基金Project supported by the Basic and Applied Basic Research Major Program of Guangdong Province,China(Grant No.2019B030302003).
文摘Extreme ultraviolet(EUV)source produced by laser-induced discharge plasma(LDP)is a potential technical means in inspection and metrology.A pulsed Nd:YAG laser is focused on a tin plate to produce an initial plasma thereby triggering a discharge between high-voltage electrodes in a vacuum system.The process of micro-pinch formation during the current rising is recorded by a time-resolved intensified charge couple device camera.The evolution of electron temperature and density of LDP are obtained by optical emission spectrometry.An extreme ultraviolet spectrometer is built up to investigate the EUV spectrum of Sn LDP at 13.5 nm.The laser and discharge parameters such as laser energy,voltage,gap distance,and anode shape can influence the EUV emission.
