The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and...The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and ms.This beamline has been specifically designed to facilitate the investigation of a wide range of rapid phenomena,such as the deformation and failure of materials subjected to intense dynamic loads.In addition,it enables the study of high-pressure and high-speed fuel spray processes in automotive engines.The light source of this beamline is a cryogenic permanent magnet undulator(CPMU)that is cooled by liquid nitrogen.This CPMU can generate X-ray photons within an energy range of 8.7-30 keV.The beamline offers two modes of operation:monochromatic beam mode with a liquid nitrogen-cooled double-crystal monochromator(DCM)and pink beam mode with the first crystal of the DCM out of the beam path.Four X-ray imaging methods were implemented in BL16U2:single-pulse ultrafast X-ray imaging,microsecond-resolved X-ray dynamic imaging,millisecond-resolved X-ray dynamic micro-CT,and high-resolution quantitative micro-CT.Furthermore,BL16U2 is equipped with various in situ impact loading systems,such as a split Hopkinson bar system,light gas gun,and fuel spray chamber.Following the completion of the final commissioning in 2021 and subsequent trial operations in 2022,the beamline has been officially available to users from 2023.展开更多
Background and Aims While chest X-ray (CXR) has been a conventional tool in intensive care units (ICUs) to identify lung pathologies, computed tomography (CT) scan remains the gold standard. Use of lung ultrasound (LU...Background and Aims While chest X-ray (CXR) has been a conventional tool in intensive care units (ICUs) to identify lung pathologies, computed tomography (CT) scan remains the gold standard. Use of lung ultrasound (LUS) in resource-rich ICUs is still under investigation. The present study compares the utility of LUS to that of CXR in identifying pulmonary edema and pleural effusion in ICU patients. In addition, consolidation and pneumothorax were analyzed as secondary outcome measures. Material and Methods This is a prospective, single centric, observational study. Patients admitted in ICU were examined for lung pathologies, using LUS by a trained intensivist;and CXR done within 4 hours of each other. The final diagnosis was ascertained by an independent senior radiologist, based on the complete medical chart including clinical findings and the results of thoracic CT, if available. The results were compared and analyzed. Results Sensitivity, specificity and diagnostic accuracy of LUS was 95%, 94.4%, 94.67% for pleural effusion;and 98.33%, 97.78%, 98.00% for pulmonary edema respectively. Corresponding values with CXR were 48.33%, 76.67%, 65.33% for pleural effusion;and 36.67%, 82.22% and 64.00% for pulmonary edema respectively. Sensitivity, specificity and diagnostic accuracy of LUS was 91.30%, 96.85%, 96.00% for consolidation;and 100.00%, 79.02%, 80.00% for pneumothorax respectively. Corresponding values with CXR were 60.87%, 81.10%, 78.00% for consolidation;and 71.3%, 97.20%, 96.00% for pneumothorax respectively. Conclusion LUS has better diagnostic accuracy in diagnosis of pleural effusion and pulmonary edema when compared with CXR and is thus recommended as an effective alternative for diagnosis of these conditions in acute care settings. Our study recommends that a thoracic CT scan can be avoided in most of such cases.展开更多
针对X光安检图像在危险品检测时背景复杂、遮挡严重、尺度多变等问题,对YOLOv7算法进行了改进,在提高检测精度的同时使网络更加轻量化。首先构建PS-ELAN模块替换原主干网络中的ELAN模块,减少网络计算量和内存占用,同时提升网络的特征提...针对X光安检图像在危险品检测时背景复杂、遮挡严重、尺度多变等问题,对YOLOv7算法进行了改进,在提高检测精度的同时使网络更加轻量化。首先构建PS-ELAN模块替换原主干网络中的ELAN模块,减少网络计算量和内存占用,同时提升网络的特征提取能力。其次将无参注意力机制SimAM与可变形卷积DCNv2融合至颈部网络的下采样阶段,提高网络对X光图像危险品关键特征的捕捉能力。最后引入Dynamic Head模块,增强检测头的尺度感知、空间感知和任务感知,提高网络的检测性能。实验结果表明,改进后的算法在自制数据集和CLCXray数据集上的平均精度均值(mean average precision,mAP)比原YOLOv7模型分别提高了4.7个百分点和1.2个百分点,参数量和计算量分别下降了16.2%和23.1%。改进后的算法提高了检测能力,同时更为轻量化,可在实际安检中起到很好的辅助作用。展开更多
An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were ...An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were empty and a total of 628 looks plump. Soft X ray radiographs showed that, still and all, a majority of the “plump" seeds were embryoless (597, 95.6%) whereas some were partially developed (17,2.7%) and only a few were really full (14, 2.2%). 2. Germination test showed that all of the radiographed hybrid seeds with fully developed embryos were germinable whereas those with partially developed embryos were ungerminable. 3. Physiologically, the growth rate of hypocotyl, the date for shedding of seed coat and spreading of cotyledons, the elongation of epicotyl, and the branching of shoot of the 11 month old seedlings showed a tendency to fall behind those of the female parent; morphologically, the 11 month old hybrid seedlings with linear leaves appeared rather short, slender and weak, whereas the seedlings of the female parents with linear_lanceolate leaves appeared rather tall, stout and strong. 4. It is considered that the hybrid may be true and the crossability reveals a close phylogenetic affinity of Cunninghamia with Cryptomeria.展开更多
Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon ...Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon in the as deposited Co/C multilayers,and this is confirmed by structure characterization using low angle X ray diffraction (LAXD).The calculation of the chemical shifts in Co C system based on Miedemas macroscopic atom model suggests that it is impossible to detect the chemical shift experimentally in the Co C compound,which is consistent with the XPS results.The presence of metallic carbide bonding is evidenced through the nature of the carbon bonding in survey taken at Co C and C Co interfaces of annealed samples.Our results also indicate that XPS is a direct method to probe the chemical bonding at the interfaces.展开更多
A new method of calculating finely the soft X ray spectra of hydrogenlike highly ionized states is presented. It is based on the relation of the ionicity and the ionization energies of hydrogenlike atoms and the new...A new method of calculating finely the soft X ray spectra of hydrogenlike highly ionized states is presented. It is based on the relation of the ionicity and the ionization energies of hydrogenlike atoms and the new model of potential function of hydrogenlike atoms. The relativistic revision and the spin orbit couping of excitation energy levels are taken into account. The calculated results are in good agreement with the experiments.展开更多
基金supported by the CAS Project for Young Scientists in Basic Research(YSBR-096)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901)+1 种基金the National Key Research and Development Program of China(Nos.2021YFF0701202,2021YFA1600703)the National Natural Science Foundation of China(Nos.U1932205,12275343).
文摘The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and ms.This beamline has been specifically designed to facilitate the investigation of a wide range of rapid phenomena,such as the deformation and failure of materials subjected to intense dynamic loads.In addition,it enables the study of high-pressure and high-speed fuel spray processes in automotive engines.The light source of this beamline is a cryogenic permanent magnet undulator(CPMU)that is cooled by liquid nitrogen.This CPMU can generate X-ray photons within an energy range of 8.7-30 keV.The beamline offers two modes of operation:monochromatic beam mode with a liquid nitrogen-cooled double-crystal monochromator(DCM)and pink beam mode with the first crystal of the DCM out of the beam path.Four X-ray imaging methods were implemented in BL16U2:single-pulse ultrafast X-ray imaging,microsecond-resolved X-ray dynamic imaging,millisecond-resolved X-ray dynamic micro-CT,and high-resolution quantitative micro-CT.Furthermore,BL16U2 is equipped with various in situ impact loading systems,such as a split Hopkinson bar system,light gas gun,and fuel spray chamber.Following the completion of the final commissioning in 2021 and subsequent trial operations in 2022,the beamline has been officially available to users from 2023.
文摘Background and Aims While chest X-ray (CXR) has been a conventional tool in intensive care units (ICUs) to identify lung pathologies, computed tomography (CT) scan remains the gold standard. Use of lung ultrasound (LUS) in resource-rich ICUs is still under investigation. The present study compares the utility of LUS to that of CXR in identifying pulmonary edema and pleural effusion in ICU patients. In addition, consolidation and pneumothorax were analyzed as secondary outcome measures. Material and Methods This is a prospective, single centric, observational study. Patients admitted in ICU were examined for lung pathologies, using LUS by a trained intensivist;and CXR done within 4 hours of each other. The final diagnosis was ascertained by an independent senior radiologist, based on the complete medical chart including clinical findings and the results of thoracic CT, if available. The results were compared and analyzed. Results Sensitivity, specificity and diagnostic accuracy of LUS was 95%, 94.4%, 94.67% for pleural effusion;and 98.33%, 97.78%, 98.00% for pulmonary edema respectively. Corresponding values with CXR were 48.33%, 76.67%, 65.33% for pleural effusion;and 36.67%, 82.22% and 64.00% for pulmonary edema respectively. Sensitivity, specificity and diagnostic accuracy of LUS was 91.30%, 96.85%, 96.00% for consolidation;and 100.00%, 79.02%, 80.00% for pneumothorax respectively. Corresponding values with CXR were 60.87%, 81.10%, 78.00% for consolidation;and 71.3%, 97.20%, 96.00% for pneumothorax respectively. Conclusion LUS has better diagnostic accuracy in diagnosis of pleural effusion and pulmonary edema when compared with CXR and is thus recommended as an effective alternative for diagnosis of these conditions in acute care settings. Our study recommends that a thoracic CT scan can be avoided in most of such cases.
文摘针对X光安检图像在危险品检测时背景复杂、遮挡严重、尺度多变等问题,对YOLOv7算法进行了改进,在提高检测精度的同时使网络更加轻量化。首先构建PS-ELAN模块替换原主干网络中的ELAN模块,减少网络计算量和内存占用,同时提升网络的特征提取能力。其次将无参注意力机制SimAM与可变形卷积DCNv2融合至颈部网络的下采样阶段,提高网络对X光图像危险品关键特征的捕捉能力。最后引入Dynamic Head模块,增强检测头的尺度感知、空间感知和任务感知,提高网络的检测性能。实验结果表明,改进后的算法在自制数据集和CLCXray数据集上的平均精度均值(mean average precision,mAP)比原YOLOv7模型分别提高了4.7个百分点和1.2个百分点,参数量和计算量分别下降了16.2%和23.1%。改进后的算法提高了检测能力,同时更为轻量化,可在实际安检中起到很好的辅助作用。
文摘An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were empty and a total of 628 looks plump. Soft X ray radiographs showed that, still and all, a majority of the “plump" seeds were embryoless (597, 95.6%) whereas some were partially developed (17,2.7%) and only a few were really full (14, 2.2%). 2. Germination test showed that all of the radiographed hybrid seeds with fully developed embryos were germinable whereas those with partially developed embryos were ungerminable. 3. Physiologically, the growth rate of hypocotyl, the date for shedding of seed coat and spreading of cotyledons, the elongation of epicotyl, and the branching of shoot of the 11 month old seedlings showed a tendency to fall behind those of the female parent; morphologically, the 11 month old hybrid seedlings with linear leaves appeared rather short, slender and weak, whereas the seedlings of the female parents with linear_lanceolate leaves appeared rather tall, stout and strong. 4. It is considered that the hybrid may be true and the crossability reveals a close phylogenetic affinity of Cunninghamia with Cryptomeria.
文摘Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon in the as deposited Co/C multilayers,and this is confirmed by structure characterization using low angle X ray diffraction (LAXD).The calculation of the chemical shifts in Co C system based on Miedemas macroscopic atom model suggests that it is impossible to detect the chemical shift experimentally in the Co C compound,which is consistent with the XPS results.The presence of metallic carbide bonding is evidenced through the nature of the carbon bonding in survey taken at Co C and C Co interfaces of annealed samples.Our results also indicate that XPS is a direct method to probe the chemical bonding at the interfaces.
文摘A new method of calculating finely the soft X ray spectra of hydrogenlike highly ionized states is presented. It is based on the relation of the ionicity and the ionization energies of hydrogenlike atoms and the new model of potential function of hydrogenlike atoms. The relativistic revision and the spin orbit couping of excitation energy levels are taken into account. The calculated results are in good agreement with the experiments.
