The photoelectron energy spectra （PESs） excited by monochromatic femtosecond x-ray pulses in the presence of a femtosecond laser are investigated. APES is composed of a set of separate peaks, showing interesting com...The photoelectron energy spectra （PESs） excited by monochromatic femtosecond x-ray pulses in the presence of a femtosecond laser are investigated. APES is composed of a set of separate peaks, showing interesting comb-like structures. These structures result from the quantum interferences between photoelectron wave packets generated at different times. The width and the localization of each peak as well as the number of peaks are determined by all the laser and x-ray parameters. Most of peak heights of the PES are higher than the classical predictions.展开更多
A new process of separating sulfur with different valance from polysulfide mixtures was developed. Sulfide, sulfite and sulfur were separated by adding acetic acid in one step. The polysulfide mixture, sulfite solutio...A new process of separating sulfur with different valance from polysulfide mixtures was developed. Sulfide, sulfite and sulfur were separated by adding acetic acid in one step. The polysulfide mixture, sulfite solution and sulfur were oxidized to sulfate by hydrogen peroxide. The products were measured by X ray Fluorescence Spectrometer(XRF) using filter method preparative specimen. The measurement needs only one set of standard sample.The effects of temperature and pH values on the separation were discussed. The results show that the recoveries range from 98.0% to 101.3% of sulfidic sulfur S( II), 97.0% to 103.0% for sulfite S(IV) and 98.4% to 100.4% for polysulfidic sulfur S(0).展开更多
The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quan...The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quantitative peaks are not well solved, and the accuracy and precision of the results are not satisfactory. This study employed the concept of mass absorption coefficient based on the internal standard method, and the full spectrum fitting and quantitative methods were used to solve the above technical problems. The sample was blended. the internal standard substance of zinc oxide was fully ground, and tablets were prepared by positive pressure method. Under certain instrumental conditions, the PXRD pattern was obtained by scanning. The percentage of gypsum fibrosum in Xiaokening tablet was obtained by quantitative analysis of full spectrum fitting internal standard by TOPAS software. The method was investigated by methodology. At the same time, the method was compared by ion chromatography, and SPSS software was used to make a significant t test on the results of the two methods. After the investigation, the average standard recovery rate of CaSO4-2H2O was 99.06%(RSD = 3.02%);and the recovery rate for simulated samples was 96.7%. The method had good specificity. After statistical analysis, there was no significant difference between the new PXRD method and the traditional method of ion chromatography.展开更多
Fourier transform infrared spectroscopy （FTIR） was employed to study the human epidermis larynx carcinoma cell lines （Hep-2） which were irradiated by different doses of X-ray. The results show that （1） the irrad...Fourier transform infrared spectroscopy （FTIR） was employed to study the human epidermis larynx carcinoma cell lines （Hep-2） which were irradiated by different doses of X-ray. The results show that （1） the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA, which restrains the reproduction of Hep-2 cells effectively, （2） the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins, lipids and the nucleic acid molecules intercellular in the greatest degree, and （3） the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently. Meanwhile, the apoptosis of these cells were detected by using flow cytometry （FCM） primarily. It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent, but is not linearly. And the apoptotic ratio of the 12 Gy dose group is the maximum （20.36%）, but the apoptotic ratios of the 2 to 8 Gy dose groups change little.展开更多
Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduce...Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings（ARCs） simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10675014)
文摘The photoelectron energy spectra （PESs） excited by monochromatic femtosecond x-ray pulses in the presence of a femtosecond laser are investigated. APES is composed of a set of separate peaks, showing interesting comb-like structures. These structures result from the quantum interferences between photoelectron wave packets generated at different times. The width and the localization of each peak as well as the number of peaks are determined by all the laser and x-ray parameters. Most of peak heights of the PES are higher than the classical predictions.
文摘A new process of separating sulfur with different valance from polysulfide mixtures was developed. Sulfide, sulfite and sulfur were separated by adding acetic acid in one step. The polysulfide mixture, sulfite solution and sulfur were oxidized to sulfate by hydrogen peroxide. The products were measured by X ray Fluorescence Spectrometer(XRF) using filter method preparative specimen. The measurement needs only one set of standard sample.The effects of temperature and pH values on the separation were discussed. The results show that the recoveries range from 98.0% to 101.3% of sulfidic sulfur S( II), 97.0% to 103.0% for sulfite S(IV) and 98.4% to 100.4% for polysulfidic sulfur S(0).
文摘The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quantitative peaks are not well solved, and the accuracy and precision of the results are not satisfactory. This study employed the concept of mass absorption coefficient based on the internal standard method, and the full spectrum fitting and quantitative methods were used to solve the above technical problems. The sample was blended. the internal standard substance of zinc oxide was fully ground, and tablets were prepared by positive pressure method. Under certain instrumental conditions, the PXRD pattern was obtained by scanning. The percentage of gypsum fibrosum in Xiaokening tablet was obtained by quantitative analysis of full spectrum fitting internal standard by TOPAS software. The method was investigated by methodology. At the same time, the method was compared by ion chromatography, and SPSS software was used to make a significant t test on the results of the two methods. After the investigation, the average standard recovery rate of CaSO4-2H2O was 99.06%(RSD = 3.02%);and the recovery rate for simulated samples was 96.7%. The method had good specificity. After statistical analysis, there was no significant difference between the new PXRD method and the traditional method of ion chromatography.
基金the Science and Technol-ogy Department of Henan province (No.0624410052)the key Ion Beam Bioengineering Laboratory of Henan Province+1 种基金the Pathology Laboratory of Zhengzhou Uni-versitythe People's Hospital of Henan Province.
文摘Fourier transform infrared spectroscopy （FTIR） was employed to study the human epidermis larynx carcinoma cell lines （Hep-2） which were irradiated by different doses of X-ray. The results show that （1） the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA, which restrains the reproduction of Hep-2 cells effectively, （2） the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins, lipids and the nucleic acid molecules intercellular in the greatest degree, and （3） the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently. Meanwhile, the apoptosis of these cells were detected by using flow cytometry （FCM） primarily. It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent, but is not linearly. And the apoptotic ratio of the 12 Gy dose group is the maximum （20.36%）, but the apoptotic ratios of the 2 to 8 Gy dose groups change little.
基金supported by the Sino-German Center for Research Promotion (No.GZ 983)the German Science Foundation DFG (No.IRTG 2101)+1 种基金the Joint Fund of the National Natural Science Foundation of Chinathe China Academy of Engineering Physics (No.U1230104)
文摘Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings（ARCs） simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.
