- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Software Platform for European XFEL: Towards Online Experimental Data Analysis
摘要： Large amount of data being generated at large scale facilities like European X-ray Free-Electron Laser (XFEL) requires new approaches for data processing and analysis. One of the most computationally challenging experiments at an XFEL is single-particle structure determination. In this paper we propose a new design for an integrated software platform which combines well-established techniques for XFEL data analysis with High Performance Data Analysis (HPDA) methods. In our software platform we use streaming data analysis algorithms with high performance computing solutions. This approach should allow analysis of the experimental dataflow in quasi-online regime.
关键词： single particle imaging,X-ray Free-Electron Laser,High Performance Data Analysis,X-ray Cross-Correlation Analysis,Expectation-Maximization
更新于2025-09-23 15:22:29
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Edge-illumination x-ray phase contrast imaging restoration using discrete curvelet regularization transform
摘要： This article considers the problem of recovering edge-illumination x-ray phase contrast (EIXPC) images from a set of potentially Poisson noisy projection measurements. The authors cast a recovery as a sparse regularization problem based on Anscombe multiscale variance stabilizing transform (MS-VST) with fast discrete curvelet transform which was applied to simulated edge-illumination x-ray phase contrast images. For accurate modelling, the noise characteristics of the EIXPCi data are used to determine the relative importance of each projection. Two implementations of curvelet sparse regularization transforms were applied, including the unequally-spaced fast Fourier transform and the wrapping-based transform. The algorithms were evaluated in terms of contrast improvement, quality of image restoration, object perceptibility, and peak signal-to-noise ratio. The methods provide nearly optimal solution without excessive memory and recovery time requirement. The performance of the proposed algorithms is demonstrated through a series of complex numerical geometric and anthropomorphic phantom studies. The results of numerical simulations demonstrate that the discrete curvelet transform with MS-VST is fast and robust, and it can effectively improve image quality, preserve and enhance edges and restore lost information while signi?cantly reducing the noise. Additionally, both sparse sampling and decreasing x-ray tube current (i.e. noisy data) lead to the reduction of radiation dose in the x-ray imaging.
关键词： x-ray imaging,x-ray phase-contrast,curvelet regularization,biomedical imaging
更新于2025-09-23 15:22:29
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Virtual subpixel approach for single-mask phase-contrast imaging using Timepix3
摘要： X-ray phase contrast imaging provides a method to distinguish materials with similar density and effective atomic number, which otherwise would be difficult using conventional X-ray absorption contrast. In recent years, multiple methods have been developed to acquire X-ray phase contrast images using incoherent laboratory sources. The single mask edge illumination setup has been demonstrated as a possible candidate for large scale applications due to its relaxed restrictions on longitudinal coherence and mask alignment, and for its ability to do bi-directional phase contrast images in a single sample exposure. Unfortunately, the single mask edge illumination setup's refraction sensitivity, and thereby signal to noise, is limited by detector artifacts. Furthermore, it requires multiple exposures to perform dark-field imaging, a method that enables imaging of micro-structures smaller than the image resolution. We propose using an Advapix detector with Timepix3 pixel-readout chip in a single mask imaging setup to improve signal to noise ratio in phase contrast images. This is achieved using the Timepix3 chip's ability to simultaneously acquire fast time of arrival and time over threshold measurement of single photon events, which enables sub-pixel identification of individual photons. In this paper, we demonstrate that signal to noise ratio can be improved by at least 67 ± 5 % using subpixel identification of single photons compared to conventional acquisitions methods. Thereby the required sample dose can be reduced considerably. This shows that there is a great potential in using Timepix3 chip to improve x-ray phase contrast imaging. Further, the results indicate the possibility for dark field imaging in a single sample exposure using Timepix3 in a single mask edge illumination setup.
关键词： X-ray detectors,X-ray radiography and digital radiography (DR),Data processing methods,Inspection with x-rays
更新于2025-09-23 15:22:29
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[IEEE 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Tangier (2017.12.4-2017.12.7)] 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Mapping of the Composition of Soils Naturally Deposited on PV Modules Anywhere in Morocco
摘要： This article constitutes a preliminary phase for the performance of a national cartography of the composition of soils naturally deposited on photovoltaic modules installed in sites of different climates. To do this, a climatic zoning of Morocco according to the De Martonne index was adopted in order to select representative sites concerned with the collection of samples. For the moment, four samples have been collected in Rabat, Errachidia, Agadir and Oujda. These samples were prepared and analyzed. Several analyzes were carried out to determine the physical, chemical and mineralogical composition of these samples. The mineralogical composition was determined via X-Ray Diffraction (XRD) and X-Ray Fluorescence analysis (XF), while characterization of the physical and chemical composition was identified using Differential Scanning Calorimetry (DSC) and Spectroscopy Infrared (IR). The results show the existence of the same abundant constituents namely: Quartz, Calcite, Dolomite, Kaolinite whose percentages differ from a climate to another.
关键词： Soils,Quartz,Calcite,Differential Scanning Calorimetry (DSC),Kaolinite,Climatic zoning,Infrared spectroscopy (IR),X-Ray Diffraction,Photovoltaic modules,Dolomite,Cartography,X-Ray Fluorescence
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Simulated Phantom Projections for Reconstruction Quality Control in Digital Tomosynthesis
摘要： IMASIM software was used to generate sets of X-ray projections for quality control in digital tomosynthesis. Corresponding projections of a polymethylmethacrylate(PMMA) phantom with the same size were taken using x-ray tomosynthesis imaging equipment. A specially designed fiduciary marker bead phantom was used to measure the relative positions of imaging system elements. A good correspondence was found between real and simulated projections and reconstructed slices. The ability to create simulated projections with predefined imperfections gives valuable benefits to analysis of overall tomosynthesis performance.
关键词： X-ray applications,digital X-ray tomosynthesis,quality control,biomedical imaging,numerical simulation
更新于2025-09-23 15:22:29
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Design and development of a mobile robotic CT system for intraoperative use
摘要： This paper presents the design of a mobile robotic computed tomography (CT) system for intraoperative use. In particular, this paper presents a novel gantry mechanism and a novel mechanism generating isocentric motions. The developed system mechanically consists of: (1) a gantry and (2) a mobile robotic body. The gantry contains the X-ray modules and has an opening mechanism that enables full 360 degree rotation. The robotic body is capable of one vertical and two isocentric rotational motions used to position the gantry. Unlike existing C-arms and mobile CT scanners, each isocentric motion is achieved using a single-DOF mechanism. With these robotic motions, the mobile robotic CT system can be used intraoperatively in both CT and fluoroscopic imaging modes. The mobile platform enables installation and removal of the device from a surgical bed. The performance of the proposed system was investigated using a laser tracking system. Experimental results show that no significant vibrations or position deviations of the X-ray modules were observed during CT scanning motion.
关键词： Isocentric motion,Robotic CT,Full-Scan,CT,X-ray,Opening Gantry
更新于2025-09-23 15:22:29
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[IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Weapon Detector System by Using X-ray Image Processing Technique
摘要： The images in the research were obtained from the internet because there is no x-ray camera. After preparing images, the next step is to test that the evaluation used to analyze the suspicious images. The images were detected by Canny Edge Detector algorithm that consists of four steps that started by smoothing the images with a Gaussian filter to eliminate interfering signals. Then, it calculated magnitude and orientation of gradient. Non-maxima Suppression and Gradient Magnitude were used to create thinner edges. The last step is double threshold algorithm to identify edge pixels and connect the edges by optimizing image recognition technique. When detecting a suspicious object, the system would send the notification. The result of this project is that the template matching algorithm was 80% accurate.
关键词： Detector,Vehicle,X-ray,Technique,Weapon
更新于2025-09-23 15:22:29
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Cathodoluminescent lamp for general lighting using carbon fiber field emission cathode
摘要： The prototype of cathodoluminescent bulb for general lighting with field emission cathode on the basis of carbon fiber is manufactured. The bulb comprises a high-voltage built-in AC-DC converter of the electric line voltage and a standard E27 cap. A high frequency converter is used to obtain high voltage. The anode voltage relative to the modulator is up to +20 kV; the cathode voltage is up to –4 kV; the current value is of the order of 1 mA. The voltage converter is located in the bulb cap and around the neck of the glass envelope.
关键词： cathode-ray-tube phosphor,carbon fiber,light sources,field emission cathodes,cathodoluminescence
更新于2025-09-23 15:22:29
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High Bandwidth Non-Resonant High Voltage Generator for X-Ray Systems
摘要： High-voltage supplies for medical X-ray systems require up to 150 kV DC at up to 100 kW to supply the tube. The challenge for the power supply however is not only to deal with the high voltage and high power demand, but also to provide short voltage rise- and fall times in the range of 100μs. A coupled interleaved circuit variant of a single active bridge concept, the coupled interleaved single active bridge converter, is demonstrated in this work providing very fast output voltage control due to its non-resonant structure. The conduction modes of the circuit are analysed in detail and compared to the uncoupled interleaved single active bridge approach, demonstrating the advantages of low inverter RMS current, zero voltage switching (or at least zero current switching) over the full operating range with constant switching frequency. Analytic expressions for the output current-duty cycle relationship are provided. Experiments on a 60 kW (low voltage equivalent) prototype show that rise times as low as five switching cycles are possible, allowing to reach the target of 100μs rise time using a switching frequency of only 50 kHz.
关键词： DC-DC power conversion,high bandwidth,high voltage generator,X-ray generator
更新于2025-09-23 15:22:29
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Is there still a role for abdominal plain X-ray in acute abdomen?
摘要： The imaging workup of patients with acute abdominal pain still starts with abdominal X-ray in several clinical settings and facilities. Unfortunately, conventional plain film is of limited utility if performed as a routine investigation. Abdominal radiography is valuable only in patients with suspected perforated viscus and large bowel obstruction. Ultrasound is mostly valuable in the vast majority of abdominal pain presentations, whereas computed tomography scan should be considered as second level test.
关键词： Bowel occlusion,Plain radiography,Abdominal X ray,Pneumoperitoneum,Acute abdomen
更新于2025-09-23 15:22:29