Integral diffraction coefficients of the crystal are the essential data of a crystal spectrometer which is extensively used to measure quantitative x-ray spectra of high temperature plasmas in kilo-electron-volt regio...Integral diffraction coefficients of the crystal are the essential data of a crystal spectrometer which is extensively used to measure quantitative x-ray spectra of high temperature plasmas in kilo-electron-volt region. An experimental method has been developed to measure the integral diffraction coefficients of crystals on beamline 4B7 of Beijing Synchrotron Radiation Facility. The integral diffraction coefficients of several crystals including polyethylene terephthalate （PET）, thallium acid phthalate （T1AP） and rubidium acid phthalate （RAP） crystals have been measured in the x-ray energy range 2100-5600 eV and compared with the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models. It is shown that the integral diffraction coefficients of these crystals are between the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models, but more close to the ＇Darwin Prins＇ model calculations.展开更多
Observation and analysis of ocean wave diffraction in near-shore and near-island region was performed with Synthetic Aperture Radar （SAR） data, using an optimized retrieval method named parameterized first-guess spe...Observation and analysis of ocean wave diffraction in near-shore and near-island region was performed with Synthetic Aperture Radar （SAR） data, using an optimized retrieval method named parameterized first-guess spectrum retrieval method. The results retrieved from ERS-SAR and ENVISAT-ASAR images showed that, in the region sheltered by land jut, the energy of long waves is reduced by 10%-20% and that the propagation direction of long waves is changed due to the effect of topography. In the shadow zone behind the island, ocean wave can propagate along the seashore instead of perpendicular to the coastline, as shown by SAR images.展开更多
基金Project supported by the Foundation of National Key Laboratory of High Temperature and Density Plasma Physics(Grant No.9140C6804020704)the National Natural Science Foundation of China(Grant No.10874156)one of the authors,GanXin-Shi,was also partially supported by the School of Physical Science and Technology in Sichuan University,China
文摘Integral diffraction coefficients of the crystal are the essential data of a crystal spectrometer which is extensively used to measure quantitative x-ray spectra of high temperature plasmas in kilo-electron-volt region. An experimental method has been developed to measure the integral diffraction coefficients of crystals on beamline 4B7 of Beijing Synchrotron Radiation Facility. The integral diffraction coefficients of several crystals including polyethylene terephthalate （PET）, thallium acid phthalate （T1AP） and rubidium acid phthalate （RAP） crystals have been measured in the x-ray energy range 2100-5600 eV and compared with the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models. It is shown that the integral diffraction coefficients of these crystals are between the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models, but more close to the ＇Darwin Prins＇ model calculations.
基金Supported by the High-Tech Research and Development Program of China (863 Program, Nos. 2001AA633070 and 2003AA604040)the National Basic Research Program of China (973 Program, No.2005CB422307)
文摘Observation and analysis of ocean wave diffraction in near-shore and near-island region was performed with Synthetic Aperture Radar （SAR） data, using an optimized retrieval method named parameterized first-guess spectrum retrieval method. The results retrieved from ERS-SAR and ENVISAT-ASAR images showed that, in the region sheltered by land jut, the energy of long waves is reduced by 10%-20% and that the propagation direction of long waves is changed due to the effect of topography. In the shadow zone behind the island, ocean wave can propagate along the seashore instead of perpendicular to the coastline, as shown by SAR images.
