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Fast X-ray imaging beamline at SSRF
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作者 Ke Li Hong-Lan Xie +5 位作者 Ya-Nan Fu Fei-Xiang Wang Guo-Hao Du Jian-Feng ji Biao Deng Ti-Qiao Xiao 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第9期68-81,共14页
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
关键词 Multiple time-scale X ray imaging Single-pulse X ray imaging Dynamic 2D imaging Dynamic micro-CT
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Array-CGH联合产前筛查对X-连锁鱼鳞病的产前遗传学研究
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作者 徐蓓 黄想媛 《现代妇产科进展》 2024年第12期926-929,共4页
目的:分析X-连锁鱼鳞病(XLI)胎儿的产前筛查异常指标、彩超及array-CGH结果,探讨其对X-连锁鱼鳞病胎儿期诊断的应用价值。方法:回顾分析2020年1月至2022年8月因孕期胎儿高危因素于深圳市宝安区妇幼保健院产前诊断中心行介入性产前诊断... 目的:分析X-连锁鱼鳞病(XLI)胎儿的产前筛查异常指标、彩超及array-CGH结果,探讨其对X-连锁鱼鳞病胎儿期诊断的应用价值。方法:回顾分析2020年1月至2022年8月因孕期胎儿高危因素于深圳市宝安区妇幼保健院产前诊断中心行介入性产前诊断的孕妇10278例,分析其胎儿array-CGH结果,对确诊X连锁鱼鳞病胎儿行父母亲芯片验证,并收集归纳其产前筛查异常指标、彩超等。结果:共检出23例胎儿样本为Xp22.31片段缺失,其中13例男性胎儿,10例女性胎儿。XLI主要来自于妊娠期血清学筛查高风险孕妇,13例男性胎儿母亲孕中期血清学筛查uE3值均显著低于正常值。1例罕见等臂假双着丝粒X染色体嵌合型Turner综合征,合并Xp22.31片段缺失型X连锁鱼鳞病。结论:对于妊娠期胎儿高危尤其是血清学筛查高风险且uE3极低孕妇,应重点对胎儿X-连锁鱼鳞病进行风险评估,应用array-CGH技术有助于XLI的确诊,对家族遗传病史不详且胎儿无结构畸形情况下的遗传咨询尤为重要。 展开更多
关键词 x-连锁鱼鳞病 STS基因 ARray-CGH
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Comparison of efficacy of lung ultrasound and chest X-ray in diagnosing pulmonary edema and pleural effusion in ICU patients: A single centre, prospective, observational study
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作者 Kunal Tewari Sumanth Pelluru +5 位作者 Deepak Mishra Nitin Pahuja Akash Ray Mohapatra Jyotsna Sharma Om Bahadur Thapa Manjot Multani 《Open Journal of Anesthesiology》 2024年第3期41-50,共10页
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
关键词 Chest X ray (CXR) CONSOLIDATION Pulmonary edema Pleural effusion Lung ultrasound (LUS) PNEUMOTHORAX
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上海光源储存环X-ray针孔相机系统设计 被引量:5
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作者 黄国庆 陈杰 +2 位作者 陈之初 冷用斌 叶恺容 《核技术》 CAS CSCD 北大核心 2010年第11期806-809,共4页
上海光源(SSRF)储存环X-ray针孔相机系统主要由X-ray引出前端、衰减片、小孔、靶片、相机、PXI控制器及图像采集等构成,数据采集处理软件在LabVIEW平台上开发,与控制系统的接口通过EPICS Shared Memory IOCcore技术实现。2009年8月开始... 上海光源(SSRF)储存环X-ray针孔相机系统主要由X-ray引出前端、衰减片、小孔、靶片、相机、PXI控制器及图像采集等构成,数据采集处理软件在LabVIEW平台上开发,与控制系统的接口通过EPICS Shared Memory IOCcore技术实现。2009年8月开始的长时间在线运行证明引出前端是安全的,在300mA运行时,测量引出窗的最高温度≤36℃。该系统设计合理、性能稳定,可在线实时测量数十μm束团横向截面尺寸,从而实现3.9nm·rad发射度的测量。 展开更多
关键词 上海光源 X—ray针孔相机 EPICS 发射度
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A Straightforward Method of Calculating Finely the Soft X-Ray Spectra of Hydrogenlike Highly Ionized-States
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作者 尹钊 张国营 张学龙 《Journal of Southeast University(English Edition)》 EI CAS 2001年第2期87-90,共4页
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
关键词 hydrogenlike ions spectra of soft X ray effect of ionicity relativistic effect
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胞元结构X-Ray三维成像及其FEM模拟
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作者 杜凤山 Gao Y X +4 位作者 Hamilton R W 臧新良 Wang Y Lee P D Song Jim 《固体力学学报》 CAS CSCD 北大核心 2006年第4期399-402,共4页
采用微纳米X-Ray断面成像技术,通过对含有CaCl2生物淀粉膨化结构材料三维成像规律的研究,确定了胞元体结构形态,并分析了断层胞元分布规律.建立了带有微细孔洞结构材料三维几何描述模型,通过理论建模和数字编程实现了与非线性有限元的连... 采用微纳米X-Ray断面成像技术,通过对含有CaCl2生物淀粉膨化结构材料三维成像规律的研究,确定了胞元体结构形态,并分析了断层胞元分布规律.建立了带有微细孔洞结构材料三维几何描述模型,通过理论建模和数字编程实现了与非线性有限元的连接,分析了微米级胞体材料受载后的场变量分布. 展开更多
关键词 微纳米X—ray 胞无结构 非线性有限元模拟
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同步辐射X-ray光源在生物学研究中的应用与进展
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作者 赵岩 刘娇 +6 位作者 谢秉合 冯伟 张珍 延鹏 左凯丽 李莉 王宏飞 《激光生物学报》 CAS 2015年第2期111-118,共8页
20世纪七十年代以来,同步辐射装置经历了三个迅速发展阶段,现在,第四代X-ray自由电子激光线站已经建成。同步辐射光源已经成为生命科学、医学、化学、物理学、材料科学等学科领域最先进的实验设施,具有广泛而重要的应用前景。本文概述... 20世纪七十年代以来,同步辐射装置经历了三个迅速发展阶段,现在,第四代X-ray自由电子激光线站已经建成。同步辐射光源已经成为生命科学、医学、化学、物理学、材料科学等学科领域最先进的实验设施,具有广泛而重要的应用前景。本文概述了同步辐射X-ray光源的特性,介绍了同步辐射X-ray光源在生物学研究中新的应用和进展。 展开更多
关键词 同步辐射光源 结构生物学 x-射线 生物大分子 细胞
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宽吸收线类星体的X-ray研究进展
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作者 王挺贵 王俊贤 《紫金山天文台台刊》 北大核心 1999年第3期248-253,共6页
本文总结最近从Xray 观测得到的关于宽吸收线类星体一些新结果, 我们和人家的结果都表明吸收物质的柱密度比原来从紫外估计的高三个量级, 在PG1411 + 442 中, 我们发现Xray 除了吸收成分外, 还有散射成分, ... 本文总结最近从Xray 观测得到的关于宽吸收线类星体一些新结果, 我们和人家的结果都表明吸收物质的柱密度比原来从紫外估计的高三个量级, 在PG1411 + 442 中, 我们发现Xray 除了吸收成分外, 还有散射成分, 其量级和UV 吸收的剩余流量一致, 从而说明以前从UV 推断的结论是有问题的。此外, 对PG1126041 的研究表明从宽吸收线类星体到Seyfert 星系的窄本征吸收线其物理性质是连续过渡的。 展开更多
关键词 类星体 吸收线 SEYFERT星系 x-射线 柱密度 观测
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Attenuation coefficients of gamma and X-rays passing through six materials 被引量:4
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作者 Xue-Dou Su Gao-Long Zhang +8 位作者 Shou-Ping Xu Wei-Wei Qu Lin Song Yu-Hua Huang Ben Wang Yi-Feng Wang Ze-Tao Zhang Wu-Fu Xu Ming-Li Wang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第1期26-31,共6页
The aim of this study was to determine the attenuation of gamma and X-rays with different energies caused by passage through different materials.To this end,different materials with a range of atomic numbers were chos... The aim of this study was to determine the attenuation of gamma and X-rays with different energies caused by passage through different materials.To this end,different materials with a range of atomic numbers were chosen to measure gamma and X-ray attenuation coefficients and to explore the mechanisms of interaction of gamma and X-rays with matter of various kinds.It is shown that the attenuation coefficients first decrease and then increase with increase in the radiation(photon)energy.The attenuation of gamma and X-rays passing through materials with high atomic number is greater than that in materials with low atomic number.The attenuation minimum is related to the atomic number of the irradiated materials.The larger the atomic number is,the lower the energy corresponding to attenuation minimum is.Photoelectric and Compton effects are the main processes when gamma rays pass through individual materials with high and low atomic numbers,respectively.Therefore,for radiotherapy and radiation protection,different methods should be considered and selected for the use of gamma and X-rays of different energies for use in different materials. 展开更多
关键词 Attenuation coefficient Interaction mechanisms Gamma rays High-energy x-rays Therapy and protection
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The Early X-ray Afterglows of Optically Bright and Dark Gamma-Ray Bursts 被引量:2
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作者 Yi-Qing Lin 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第5期555-560,共6页
A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D... A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D-GRBs. Our results show that the distributions of the X-ray afterglow fluxes (Fx), the gamma-ray fluxes (Sγ), and the ratio (Rγ,x) are similar for the two kinds of GRBs, that any observed differences should be simply statistical fluctuation. These results indicate that the progenitors of the two kinds of GRBs are of the same population with comparable total energies of explosion. The suppression of optical emission in the D-GRBs should result from circumburst but not from their central engine. 展开更多
关键词 gamma rays BURSTS
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Statistical study of EUV and X-ray transient brightenings 被引量:3
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作者 Jing-Wei Li Hui Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第7期696-706,共11页
Using the visual inspection and base difference method and data from the X-ray Telescope (XRT) onboard Hinode and TRACE with improved spatial and temporal resolution, we selected 48 X-ray transient brightenings (X... Using the visual inspection and base difference method and data from the X-ray Telescope (XRT) onboard Hinode and TRACE with improved spatial and temporal resolution, we selected 48 X-ray transient brightenings (XTBs) and 237 EUV transient brightenings (ETBs) to study the connection between these two types of transient brightenings (TBs). These ETBs and XTBs have smaller areas (8.42 Mm^2 and 36.3 Mm^2, respectively, on average) and shorter durations (9.0 min and 6.9 min, respectively, on average) than previous studies. These XTBs show three types of morphological structure: point-like, single-loop and multiple-loop. We find only 20% of the ETBs have corresponding XTBs while the other 80% have no X-ray signatures at all. This is presumably due to the small amount of released energy, which is not enough to heat the plasma to coronal temperatures which produce X-ray emission rather than being due to the limitation of spatial resolution and temperature sensitivity of the X-ray instrument. These small ETBs may significantly contribute to the coronal heating. 展开更多
关键词 SUN x-rays gamma rays -- Sun UV radiation -- Sun CORONA
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新发突变基因的新生儿X-连锁肌小管肌病1例并文献回顾 被引量:1
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作者 胡勇 黄希 《中南大学学报(医学版)》 CAS CSCD 北大核心 2024年第3期491-496,共6页
X-连锁肌小管肌病(X-linked myotubular myopathy,XLMTM)是一种罕见的先天性肌病。四川大学华西第二医院于2021年2月收治1例临床表现为肌张力低下、伴有特殊面容、需持续呼吸机辅助通气的男性新生儿,36~(+2)周早产,出生后出现呼吸困难... X-连锁肌小管肌病(X-linked myotubular myopathy,XLMTM)是一种罕见的先天性肌病。四川大学华西第二医院于2021年2月收治1例临床表现为肌张力低下、伴有特殊面容、需持续呼吸机辅助通气的男性新生儿,36~(+2)周早产,出生后出现呼吸困难及治疗后撤机困难,伴有四肢肌张力低下、吞咽功能障碍及特殊外貌特征(四肢细长、面部狭长、高腭弓、双手垂腕、阴囊空虚、细长指/趾等),经基因检测确诊为XLMTM。其全外显子家系测序结果提示父亲、外公、外婆均无变异,母亲存在杂合变异,致病突变为MTM1(OMIM:300415),染色体位置为chrX-150649714,核苷酸变化为c.868-2A>C。该患儿具有典型的外貌特征,且经基因检测发现为新发的突变基因。对存在肌张力异常及特殊面容的患儿,早期进行基因检测对准确诊断XLMTM有重要意义。 展开更多
关键词 x-连锁肌小管肌病 MTM1基因 基因突变 新生儿
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DIFFERENTIAL SCANNING CALORIMETRY AND X-RAY DIFFRACTION STUDIES ON AGING BEHAVIOR OF Zn-Al ALLOYS 被引量:2
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作者 X.L. Xu, Z. W. Yu, S.J. Ji, J.C. Sun and Z.K. Hei (Dalian Maritime University, Dalian 116024, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2001年第2期109-114,共6页
Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities o... Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and α' phase formed by quenching would reduce with the increase of Zn content and the precipitation of η-Zn phases even when aging at ambient temperature, so that the exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by XRD. The microstructure change during aging was observed by TEM. 展开更多
关键词 Aging of materials Aluminum alloys Differential scanning calorimetry X ray diffraction
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Very Early Optical Afterglows for Geometric Models of X-ray Flashes and X-ray Rich GRBs 被引量:1
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作者 Ting Yan Da-Ming Wei Yi-Zhong Fan 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第6期777-788,共12页
If X-ray flashes (XRFs) and X-ray rich Gamma-ray Bursts (XRRGs) have the same origin as the Gamma-ray bursts (GRBs) but are viewed off-center from structured jets, their early afterglows may differ from those of... If X-ray flashes (XRFs) and X-ray rich Gamma-ray Bursts (XRRGs) have the same origin as the Gamma-ray bursts (GRBs) but are viewed off-center from structured jets, their early afterglows may differ from those of GRBs, and when the ultra-relativistic outflow inter- acts with the surrounding medium, there are two shocks formed, a forward shock (FS), and a reverse shock (RS). We calculate numerically the early afterglow powered by uniform jets, Gaussian jets and power-law jets in the forward-reverse shock scenario. A set of differential equations govern the dynamical evolution. The synchrotron self-Compton effect has been taken into account in the calculation. In the uniform jets, the very early afterglows of XRRGs and XRFs are significantly lower than the GRBs and the observed peak times of RS emission are later in the interstellar medium environment. The RS components in XRRGs and XRFs are difficult to detect, but in the stellar wind environment, the reduction of the very early flux and the delay of the RS peak time are not so remarkable. In nonuniform jets (Gaussian and power-law jets), where there are emission materials on the line of sight, the very early light curve resembles equivalent isotropic ejecta in general although the RS flux decay index shows notable deviations if the RS is relativistic (in stellar wind). 展开更多
关键词 x-rays general -- Gamma rays bursts -- radiation mechanisms NON-THERMAL
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Study of NdCl_3-FeCl_3-Graphite Intercalation Compounds by X-Ray Photoelectron Spectroscopy 被引量:1
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作者 侯仰龙 韦永德 《Journal of Rare Earths》 SCIE EI CAS CSCD 2001年第1期18-20,共3页
NdCl 3 FeCl 3 graphite intercalation compounds were synthesized by molten salt exchange method. The state of the intercalates and the relative contents of Nd, Fe, Cl, C in the product were determined by X ray ph... NdCl 3 FeCl 3 graphite intercalation compounds were synthesized by molten salt exchange method. The state of the intercalates and the relative contents of Nd, Fe, Cl, C in the product were determined by X ray photoelectron spectroscopy(XPS). From the XPS data, it is concluded that the binding energy of Fe2p electrons is about 711 20~710 3 eV, the binding energy of Nd3d electrons is about 983 08~983 20 eV, and Fe in the product has two valence states (Fe 3+ and Fe 2+ ). 展开更多
关键词 rare earths neodymium chloride graphite intercalation compounds X ray photoelectron spectroscopy
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On the power-law distributions of X-ray fluxes from solar flares observed with GOES 被引量:1
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作者 You-Ping Li Li Feng +2 位作者 Ping Zhang Si-Ming Liu Wei-Qun Gan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第10期99-106,共8页
The power-law frequency distributions of the peak flux of solar flare X-ray emission have been studied extensively and attributed to a system having self-organized criticality (SOC). In this paper, we first show tha... The power-law frequency distributions of the peak flux of solar flare X-ray emission have been studied extensively and attributed to a system having self-organized criticality (SOC). In this paper, we first show that, so long as the shape of the normalized light curve is not correlated with the peak flux, the flux histogram of solar flares also follows a power-law distribution with the same spectral index as the power- law frequency distribution of the peak flux, which may partially explain why power-law distributions are ubiquitous in the Universe. We then show that the spectral indexes of the histograms of soft X-ray fluxes observed by GOES satellites in two different energy channels are different: the higher energy channel has a harder distribution than the lower energy channel, which challenges the universal power-law distribution predicted by SOC models and implies a very soft distribution of thermal energy content of plasmas probed by the GOES satellites. The temperature (T) distribution, on the other hand, approaches a power-law dis- tribution with an index of 2 for high values of T. Hence the application of SOC models to the statistical properties of solar flares needs to be revisited. 展开更多
关键词 Sun: flares -- Sun: x-rays Gamma rays -- methods: statistical
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Key Techniques of the X-ray Inspection Real-time Imaging Pipeline Robot 被引量:1
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作者 邓宗全 Xu +4 位作者 Fengping Zhang Xiaohua Chen Hongjun 《High Technology Letters》 EI CAS 2004年第2期54-56,共3页
This paper presents a robotic system for weld-joint inspection of the big-caliber pipeline, which is developed for the purpose of being utilized as automation platform for X-ray real-time imaging inspection technique ... This paper presents a robotic system for weld-joint inspection of the big-caliber pipeline, which is developed for the purpose of being utilized as automation platform for X-ray real-time imaging inspection technique (RTIIT). The robot can perform autonomous seeking and locating of weld-seam position in-pipe, and under the control of synchro-follow control technique it can accomplish the technologic task of weld inspection. The robotic system is equipped with a small focal spot and directional beam X-ray tube, so the higher definition image of weld-seam can be obtained. Several key techniques about the robotic system developed are also explained in detail. Its construction is outlined. 展开更多
关键词 x-射线检查 实时图像检查 机器人 焊接 管道
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Broken-up spectra of the loop-top hard X-ray source during a solar limb flare 被引量:1
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作者 Hao Ning Yao Chen +3 位作者 Jeongwoo Lee Zhao Wu Yang Su Xiang-Liang Kong 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第12期207-216,共10页
Solar hard X-rays(HXRs) appear in the form of either footpoint sources or coronal sources. Each individual source provides its own critical information on acceleration of nonthermal electrons and plasma heating. Earli... Solar hard X-rays(HXRs) appear in the form of either footpoint sources or coronal sources. Each individual source provides its own critical information on acceleration of nonthermal electrons and plasma heating. Earlier studies found that the HXR emission in some events manifests a broken-up power-law spectrum, with the break energy around a few hundred keV based on spatially-integrated spectral analysis,and it does not distinguish the contributions from individual sources. In this paper, we report on the brokenup spectra of a coronal source studied using HXR data recorded by Reuven Ramaty High Energy Solar Spectroscopic Imager(RHESSI) during the SOL2017–09–10 T16:06(GOES class X8.2) flare. The flare occurred behind the western limb and its footpoint sources were mostly occulted by the disk. We could clearly identify such broken-up spectra pertaining solely to the coronal source during the flare peak time and after. Since a significant pileup effect on the RHESSI spectra is expected for this intense solar flare, we have selected the pileup correction factor, p = 2. In this case, we found the resulting RHESSI temperature(~30MK) to be similar to the GOES soft X-ray temperature and break energies of 45–60 keV. Above the break energy, the spectrum hardens with time from spectral index of 3.4 to 2.7, and the difference in spectral indices below and above the break energy increases from 1.5 to 5 with time. However, we note that when p = 2 is assumed, a single power-law fitting is also possible with the RHESSI temperature higher than the GOES temperature by ~10MK. Possible scenarios for the broken-up spectra of the loop-top HXR source are briefly discussed. 展开更多
关键词 acceleration of particles Sun:corona Sun:flares Sun:UV radiation Sun:x-rays gamma rays
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布罗索尤单抗治疗儿童及成人X-连锁低磷性佝偻病的疗效观察 被引量:2
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作者 刘清扬 后子靖 +3 位作者 杨紫霞 刘鑫 张波 唐彦 《罕见病研究》 2024年第1期108-113,共6页
本文通过检索北京协和医院于2021年1月至2022年12月期间诊断X-连锁低磷性佝偻病(XLH)且接受布罗索尤单抗治疗的患者,对患者的临床特征、布罗索尤单抗治疗前后的临床指标变化、治疗期间的药品不良反应等进行描述,初步评价布罗索尤单抗用... 本文通过检索北京协和医院于2021年1月至2022年12月期间诊断X-连锁低磷性佝偻病(XLH)且接受布罗索尤单抗治疗的患者,对患者的临床特征、布罗索尤单抗治疗前后的临床指标变化、治疗期间的药品不良反应等进行描述,初步评价布罗索尤单抗用于XLH患者的有效性和安全性。结果显示,3例儿童XLH患者和1例成年XLH患者接受布罗索尤单抗治疗,全部患者血磷水平较治疗前提高,3例儿童患者血磷均达到参考值范围下限以上,全部患者较治疗前血碱性磷酸酶(ALP)降低,1例成年患者治疗2.5年后血ALP接近正常范围。1例儿童患者治疗48周后肾脏超声可见小结晶,1例儿童患者和1例成年患者治疗前出现血甲状旁腺激素(PTH)水平升高,用药后血PTH进一步升高。总之,布罗索尤单抗用于XLH患者,提高了血磷水平并保持相对稳定,同时降低了血ALP水平,治疗期间未观察到严重不良反应,为布罗索尤单抗这一新药用于XLH患者提供参考。 展开更多
关键词 x-连锁低磷性佝偻病 临床特征 布罗索尤单抗 疗效 安全性
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Observation of cavitation and water-refilling processes in plants with X-ray phase contrast microscopy 被引量:1
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作者 XUE Yanling XIAO Tiqiao +5 位作者 DU Guoha TONG Yajun LIU Huiqiang DENG Biao XIE Honglan XU Hongjie 《Nuclear Science and Techniques》 SCIE CAS CSCD 2013年第6期1-6,共6页
With the spatial coherence of X-rays and high flux and brightness of the 3rd generation synchrotron radiation facility,X-ray phase contrast microscopy(XPCM)at Shanghai Synchrotron Radiation Facility(SSRF)can provide h... With the spatial coherence of X-rays and high flux and brightness of the 3rd generation synchrotron radiation facility,X-ray phase contrast microscopy(XPCM)at Shanghai Synchrotron Radiation Facility(SSRF)can provide high resolution dynamic imaging of low electron density materials in principle.In this paper,we investigated the cavitation and water-refilling processes in rice and bamboo leaves utilizing XPCM at SSRF.The occurrence of xylem cavitation was recorded in vivo.The study also revealed that under different dehydration conditions,cavitation occurs in different degrees,and therefore,the refilling process is different.The results demonstrate that SSRF can provide high enough fluxes to study dynamic processes in plants in real-time,and XPCM is expected to be a promising method to reveal the mechanisms of cavitation and its repair in plants nondestructively. 展开更多
关键词 相衬显微镜 显微镜观察 植物 x-射线 填充过程 气蚀 上海同步辐射装置 水稻
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