共查询到20条相似文献,搜索用时 15 毫秒
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Tianxi Sun Meiling Zhang Zhiguo Liu Zhiguang Zhang Gang Li Yongzhong Ma Xiaoguang Du Quanjie Jia Yu Chen Qingxi Yuan Wanxia Huang Peiping Zhu Xunliang Ding 《Journal of synchrotron radiation》2009,16(1):116-118
An imaging system based on a polycapillary half‐focusing X‐ray lens (PHFXRL) and synchrotron radiation source has been designed. The focal spot size and the gain in power density of the PHFXRL were 22 µm (FWHM) and 4648, respectively, at 14.0 keV. The spatial resolution of this new imaging system was better than 5 µm when an X‐ray charge coupled device with a pixel size of 10.9 × 10.9 µm was used. A fossil of an ancient biological specimen was imaged using this system. 相似文献
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在上海光源硬X射线微聚焦光束线站(BL15U1)上, 基于EPICS软件平台, 集成运动控制, 光强探测, 荧光探测等功能, 实现了"飞行"模式 (on-the-fly) X射线扫描微束荧光成像方法. 用"飞行"扫描X射线荧光成像法获得了标准镍网, 以及微量元素Cu, Zn,K, Fe在样品老鼠脾内的分布图像, 结果显示该方法不但在速度上有了极大的提高, 而且获得的元素分布图像具有高质量.
关键词:
快速扫描X射线微束荧光成像
同步辐射
微量元素分布 相似文献
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Jing Li Chunfu Zhang Ke Yang Ping Liu Lisa X. Xu 《Journal of synchrotron radiation》2011,18(4):612-616
Angiogenesis, new blood vessels sprouting from pre‐existing vessels, is essential to tumor growth, invasion and metastasis. It can be used as a biomarker for early stage tumor diagnosis and targeted therapy. To visualize angiogenesis many molecular imaging modalities have been used. In this study a novel X‐ray molecular targeting probe using superparamagnetic iron oxide (SPIO) conjugated with arginine–glycine–aspartic acid (SPIO–RGD) has been developed. Based on the extremely high sensitivity to the iron element of synchrotron radiation X‐ray fluorescence and the superior spatial resolution of third‐generation synchrotron radiation, the feasibility of SPIO–RGD as a promising molecular probe for imaging tumor angiogenesis has been demonstrated. 相似文献
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Ping Liu Jianqi Sun Yijing Guan Weisheng Yue Lisa X. Xu Yan Li Guilin Zhang Yeukuang Hwu Jung Ho Je G. Margaritondo 《Journal of synchrotron radiation》2008,15(1):36-42
In the present study the feasibility of applying synchrotron radiation to the morphological study of early‐stage lung cancer has been investigated. Lewis lung cancer was implanted and grown in a nude mouse for different periods, and imaged using phase‐contrast synchrotron X‐rays. Morphological differences were clearly shown between the normal lung and cancerous tissues at this early stage. Irregular and tortuous angiogenesis were found in the periphery region of the developing lung cancer. Results from this study indicate that synchrotron X‐rays can be used for imaging cancer development and progression with minimal invasion. 相似文献
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Nondestructive imaging of the internal microstructure of vessels and nerve fibers in rat spinal cord using phase‐contrast synchrotron radiation microtomography 下载免费PDF全文
Jianzhong Hu Ping Li Xianzhen Yin Tianding Wu Yong Cao Zhiming Yang Liyuan Jiang Shiping Hu Hongbin Lu 《Journal of synchrotron radiation》2017,24(2):482-489
The spinal cord is the primary neurological link between the brain and other parts of the body, but unlike those of the brain, advances in spinal cord imaging have been challenged by the more complicated and inhomogeneous anatomy of the spine. Fortunately with the advancement of high technology, phase‐contrast synchrotron radiation microtomography has become widespread in scientific research because of its ability to generate high‐quality and high‐resolution images. In this study, this method has been employed for nondestructive imaging of the internal microstructure of rat spinal cord. Furthermore, digital virtual slices based on phase‐contrast synchrotron radiation were compared with conventional histological sections. The three‐dimensional internal microstructure of the intramedullary arteries and nerve fibers was vividly detected within the same spinal cord specimen without the application of a stain or contrast agent or sectioning. With the aid of image post‐processing, an optimization of vessel and nerve fiber images was obtained. The findings indicated that phase‐contrast synchrotron radiation microtomography is unique in the field of three‐dimensional imaging and sets novel standards for pathophysiological investigations in various neurovascular diseases. 相似文献
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A one-dimensional quantum model for nuclear resonant scattering using synchrotron radiation has been developed. This model
gives a clear physical interpretation of the most prominent features of the coherent forward scattering process namely, the
“speed-up” and “dynamical beat” effects. The form of the solution, for the time-dependent forward scattered intensity of the
resonant radiation from the resonant medium after synchrotron radiation excitation, is a finite series. This unique solution
can be interpreted in terms of a summation over all multiple forward scattering paths the radiation takes in reaching the
detector. The resonant medium is represented by a linear chain of N effective resonant nuclei. The analysis starts from a coupled set of quantum mechanical equations for the relevant amplitudes
in frequency space. Transformation to the time domain gives an analytical expression for the forward scattered intensity.
The contribution of every order of the multiple scattering processes from the N effective nuclei appears naturally. The expression gives a clear physical understanding of all relevant aspects of resonant
forward nuclear scattering. Furthermore, the present formalism allows the consideration of incoherent processes. This permits
the study of processes in which there is gamma emission with recoil or emission of internal-conversion electrons.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Poonamlata S. Yadav Y. S. Kashyap Tushar Roy P. S. Sarkar A. Sinha 《Journal of synchrotron radiation》2008,15(1):100-105
Phase‐contrast imaging provides enhanced image contrast and is important for non‐destructive evaluation of structural materials. In this paper, experimental results on in‐line phase‐contrast imaging using a synchrotron source (ELETTRA, Italy) for objects required in material science applications are discussed. Experiments have been carried out on two types of samples, pyrocarbon‐coated zirconia and pyrocarbon‐coated alumina microspheres. These have applications in both reactor and industrial fields. The phase‐contrast imaging technique is found to be very useful in visualizing and determining the coating thickness of pyrocarbon on zirconia and alumina microspheres. The experiments were carried out at X‐ray energies of 16, 18 and 20 keV and different object‐to‐detector distances. The results describe the contrast values and signal‐to‐noise ratio for both samples. A comprehensive study was carried out to determine the thickness of the pyrocarbon coating on zirconia and alumina microspheres of diameter 500 µm. The advantages of phase‐contrast images are discussed in terms of contrast and resolution, and a comparison is made with absorption images. The results show considerable improvement in contrast with phase‐contrast imaging as compared with absorption radiography. 相似文献
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Fluorescence tomography utilizing focussed, tunable, monoenergetic X-rays from synchrotron light sources hold the promise
of a non-invasive analytic tool for studying trace elements in specimens, particularly biological, at spatial resolutions
of the order of micrometers. This note reports an early test at the National Synchrotron Light Source at Brookhaven National
Laboratories in which fluorescence tomographic scans were successfully made of trace elements of iron and titanium in NBS
standard glass and in a bee. 相似文献
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Daniele Pelliccia Christopher M. Poole Jayde Livingstone Andrew W. Stevenson Lloyd M. L. Smyth Peter A. W. Rogers Daniel Haüsermann Jeffrey C. Crosbie 《Journal of synchrotron radiation》2016,23(2):566-573
The protocol for image‐guided microbeam radiotherapy (MRT) developed for the Australian Synchrotron's Imaging and Medical Beamline (IMBL) is described. The protocol has been designed for the small‐animal MRT station of IMBL to enable future preclinical trials on rodents. The image guidance procedure allows for low‐dose monochromatic imaging at 50 keV and subsequent semi‐automated sample alignment in 3D with sub‐100 µm accuracy. Following the alignment, a beamline operation mode change is performed and the relevant beamline components are automatically aligned for the treatment (pink) beam to be delivered on the sample. Here, the small‐animal MRT station, the parameters and procedures for the image guidance protocol, as well as the experimental imaging results using phantoms are described. Furthermore, the experimental validation of the protocol using 3D PRESAGE® dosimeters is reported. It is demonstrated that the sample alignment is maintained after the mode change and the treatment can be delivered within the same spatial accuracy of 100 µm. The results indicate that the proposed approach is viable for preclinical trials of small‐animal MRT. 相似文献
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《X射线光谱测定》2005,34(6):477-480
At photon energies below 100 keV, coherent scatter becomes important and because of its sharply forward peaked nature, it is the dominant interaction at small angles. Further, in the momentum transfer region above 0.5 Å?1, free atom form factors are sufficient to describe coherent scattering. The angular distribution of the coherent scattering carries detailed information about the object and can be used as a signature of the tissue type of the object. The aim of this work was to analyze the scattering properties of different human tissues according to histological classifications. The coherent scattering signatures of healthy and neoplastic breast, uterus and kidney tissues were measured using x‐ray synchrotron radiation at the XRD2 beamline at the Brazilian Synchrotron Light Laboratory (LNLS). Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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Thomas Schramm Gerd Ganteför Andras Bodi Partick Hemberger Thomas Gerber Bernd von Issendorff 《Applied Physics A: Materials Science & Processing》2014,115(3):771-779
A new experimental setup for photoelectron spectroscopy of size-selected cluster ions using synchrotron VUV radiation as generated by the Swiss Light Source is presented. An intense positively charged cluster ion beam is produced in a high-intensity magnetron sputter source. The clusters are subsequently mass selected in a sector magnet. To maximize the residence time of the cluster ions in the ionization region of the velocity map imaging spectrometer, the cluster ion beam is decelerated where it crosses the light beam. First experiments on (MoO3) n + (n = 69 and 59) cluster cations show that the approach is capable of delivering photoelectron spectra of size-selected transition metal cluster ions. 相似文献
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Imaging characteristics of toroidal and ellipsoidal mirrors for synchrotron radiation source Indus-1
We discuss and compare the imaging characteristics of toroidal and ellipsoidal mirrors for different horizontal acceptances
of synchrotron radiation source Indus-1; using a ray tracing method. It has been shown that the toroidal and ellipsoidal mirrors
have similar focussing behaviour at small horizontal acceptances. For large horizontal acceptances, toroidal mirror shows
an asymmetry in the focussed image. Though the data used here are for Indus-1, the results are generally valid for any bending
magnet synchrotron radiation source incident at grazing angles on these mirrors. 相似文献