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monochromatic energy computed tomography image for active intestinal hemorrhage:A model investigation

World Journal of Gastroenterology 2015年第1期21卷 214-220页

作者： Wen-Dong Liu Xing-Wang Wu Jun-Mei Hu Bin Wang Bin Liu Department of Radiology the First Affiliated Hospital of Anhui Medical University Department of Epidemiology and Statistics Anhui Medical University

AIM: To investigate the value of computed tomography(CT) spectral imaging in the evaluation of intestinal ***: Seven blood flow rates were simulated in *** spectral CT and mixed-energy CT scanswere performed for each rate(0.5,0.4,0.3,0.2,0.1,0.05 and 0.025 m L/min).The detection rates and the contrast-to-noise ratios(CNRs) of the contrast agent extravasation regions were compared between the two scanning methods in the arterial phase(AP) and the portal venous phase(PVP).Comparisons of the CNR values between the PVP and the AP were made for each energy level and carried out using a completely random t test.A χ2 test was used to compare the detection rates obtained from the two scanning ***: The total detection rates for energy spectral CT and mixed-energy CT in the AP were 88.57%(31/35) and 65.71%(23/35),respectively,and the difference was significant(χ2 = 5.185,P = 0.023); the total detection rates in the PVP were 100.00%(35/35) and 91.4%(32/35),respectively,and the difference was not significant(χ2 = 1.393,P = 0.238).In the AP,the CNR of the contrast agent extravasation regions was 3.58 ± 2.09 on the mixed-energy CT images,but the CNRs were 8.78 ± 7.21 and 8.83 ± 6.75 at 50 and 60 keV,respectively,on the single-energy CT images,which were significantly different(3.58 ± 2.09 vs 8.78 ± 7.21,P = 0.031; 3.58 ± 2.09 vs 8.83 ± 6.75,P = 0.029).In the PVP,the differences between the CNRs at 40,50 and 60 keV different monochromatic energy levels and the polychromatic energy images were significant(19.35 ± 10.89 vs 11.68 ± 6.38,P = 0.010; 20.82 ± 11.26 vs 11.68 ± 6.38,P = 0.001; 20.63 ± 10.07 vs 11.68 ± 6.38,P = 0.001).The CNRs at the different energy levels in the AP and the PVP were significantly different(t =-2.415,-2.380,-2.575,-2.762,-2.945,-3.157,-3.996 and-3.189).CONCLUSION: monochromatic energy imaging spectral CT is superior to polychromatic energy images for the detection of intestinal hemorrhage,and the detection was easier in t

关键词： Spectral imaging Computed tomography monochromatic

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An important criterion for reliable multi-monochromatic x-ray imager diagnostics and its impact on the reconstructed images

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High Power Laser Science and Engineering 2015年第3期3卷 59-65页

作者： T.Nagayama R.C.Mancini D.Mayes R.Tommasini R.Florido Physics Department University of Nevada Lawrence Livermore National Laboratory Departamento de Física Universidad de Las Palmas de Gran Canaria

Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion(ICF) science. A multimonochromatic x-ray imager, MMI, records the spectral signature from an ICF implosion core with time resolution, 2D spatial resolution and spectral resolution. While narrow-band images and 2D space-resolved spectra from the MMI data constrain the temperature and the density spatial structure of the core, the accuracy of the images and the spectra highly depends on the quality of the MMI data and the processing tools. Here, we synthetically investigate the criterion for reliable MMI diagnostics and its effects on the accuracy of the reconstructed images. The pinhole array tilt determines the object spatial sampling efficiency and the minimum reconstruction width, w. When the spectral width associated with w is significantly narrower than the spectral linewidth, the line images reconstructed from the MMI data become reliable. The MMI setup has to be optimized for every application to meet this criterion for reliable ICF diagnostics.

关键词： high power laser inertial confinement fusion monochromatic imager x-ray diagnostics

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Synthesizing monochromatic 3-D images by multiple-exposure rainbow holography with vertical area-partition approach

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Science China Mathematics 2002年第12期45卷 1603-1609页

作者：翟宏琛母国光王明伟刘福民 1. Institute of Modern Optics Nankai University Key Laboratory for Optoelectronic Information Science & Technology of Ministry of Education 300071 Tianjin China

We report for the first time the theoretical analysis and experimental results of a white-light reconstructed monochromatic 3-D image synthesizing tomograms by multiple rainbow holo-graphy with vertical-area partition (VAP) approach. The theoretical and experimental results show that 3-D monochromatic image can be synthesized by recording the master hologram by VAP ap-proach without any distortions either in gray scale or in geometrical position. A 3-D monochromatic image synthesized from a series of medical tomograms is presented in this paper for the first time.

关键词： multiple-exposure rainbow holography, holographic 3-D synthesis, vertical-area partition, monochromatic image, vision gray level, geometric aberration.

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Feasibility of Improved Attenuation Correction for SPECT Reconstruction in the Presence of Dense Materials Using Dual-Energy Virtual monochromatic CT: A Phantom Study

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Open Journal of Medical Imaging 2015年第4期5卷 183-193页

作者： Sachiko Yamada Takashi Ueguchi Eku Shimosegawa Koichi Fujino Takeshi Shimazu Kenya Murase Jun Hatazawa Department of Radiology Osaka University Hospital Osaka Japan Department of Medical Physics and Engineering Osaka University Graduate School of Medicine Osaka Japan Center for Information and Neural Networks National Institute of Information and Communications Technology Osaka Japan Graduate School of Frontier Biosciences Osaka University Osaka Japan Department of Molecular Imaging in Medicine Osaka University Graduate School of Medicine Osaka Japan Department of Traumatology and Acute Critical Medicine Osaka University Graduate School of Medicine Osaka Japan Department of Nuclear Medicine and Tracer Kinetics Osaka University Graduate School of Medicine Osaka Japan

Objective: Computed tomography (CT)-based attenuation correction (CTAC) offers the clear benefit of reliable reconstruction of single-photon emission computed tomography (SPECT) images through its ability to achieve object-specific attenuation maps, but artifacts from dense materials often deteriorate CTAC performance. Therefore, we investigate the feasibility of CTAC in the presence of dense materials using dual-energy virtual monochromatic CT data. Methods: A sodium pertechnetate-filled cylindrical uniform phantom, with a pair of undiluted iodine syringes attached, is scanned with a dual-source CT scanner to obtain both single-energy (120 kVp) polychromatic and dual-energy (80 kVp/140 kVp with tin filtering) virtual monochromatic CT images. The single-energy and the dual-energy CT images are then converted to attenuation maps at 141 keV. SPECT images are reconstructed from 99mTc emission data of the phantom using each single-energy and dual-energy attenuation map and incorporating CTAC procedure. A region-of-in- terest analysis is performed to quantitatively compare the attenuation maps between the single-energy and the dual-energy techniques, each at an iodine-free position and a position adjacent to the iodine solutions. Results: At the iodine-free position, the phantom provides a uniform distribution of attenuation maps in both the single-energy and the dual-energy techniques. In the presence of adjacent iodine solutions, however, severe artifacts appeare in the single-energy CT images. These artifacts make attenuation values fluctuate, resulting in erroneous pixel values in the CTAC SPECT images. In contrast, dual-energy CT strongly suppresses the artifacts and hence improves the uniformity of the attenuation maps and the resultant SPECT images. Conclusions: Dual-energy CT with virtual monochromatic reconstruction has the potential to substantially reduce artifacts arising from dense materials. It has the potential to improve the accuracy of attenuation maps a

关键词： SPECT Attenuation Correction Dual-Energy CT Virtual monochromatic Imaging Artifact Reduction

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Study on the Effect of monochromatic Light on the Growth of the Red Tide Diatom <i>Skeletonema Costatum</i>

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Optics and Photonics Journal 2012年第3期2卷 152-156页

作者： Hongli Miao Lina Sun Qingzhen Tian Shanshan Wang Jing Wang College of information science and engineering Ocean University of China Laoshan District Qingdao Shandong China

Effects of light intensity and quality of three kinds of LED monochromatic lights (blue, green, and red) on the growth of Skeletonema costatum are investigated in batch culture conditions. Seven light intensities (20, 30, 40, 45, 50, 60 and 80 μmol·m-2·s-1) are used to evaluate the specific growth rate, spectrum absorption coefficient and saturated light intensity of LED monochromatic light. Results show that the growth rates of Skeletonema costatum increase with the enhanced light intensity;however, the light level beyond the saturation light intensity inhibited the growth of Skeletonema costatum. Compared with red and green light, the growth rate of Skeletonema costatum under blue light is higher within saturated light intensity, and saturated light intensity of LED monochromatic light is lower under blue light and higher under green light. It is concluded that under different monochromatic light, the saturated light intensity decreases and the growth rate increases with the increasing of spectrum absorption coefficient.

关键词： monochromatic Light Saturated Light Intensity Skeletonema Costatum Growth Rate Red Tide

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Analytical and Numerical Investigations of Probabilistic monochromatic Problem

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Journal of Applied Mathematics and Physics 2019年第4期7卷 793-808页

作者： Stefan Schmuck Jakob Svensson Istituto di Fisica del Plasma CNR Milan Italy Max-Planck-Institut für Plasmaphysik Teilinstitut Greifswald Greifswald Germany

A probabilistic formalism, relying on Bayes’ theorem and linear Gaussian inversion, is adapted, so that a monochromatic problem can be investigated. The formalism enables an objective test in probabilistic terms of the quantities and model concepts involved in the problem at hand. With this formalism, an amplitude (linear parameter), a frequency (non-linear parameter) and a hyperparameter of the Gaussian amplitude prior are inferred jointly given simulated data sets with Gaussian noise contributions. For the amplitude, an analytical normal posterior follows which is conditional on the frequency and the hyperparameter. The remaining posterior estimates the frequency with an uncertainty of MHz, while the convolution of a standard approach would achieve an uncertainty of some GHz. This improvement in the estimation is investigated analytically and numerically, revealing for instance the positive effect of a high signal-to-noise ratio and/or a large number of data points. As a fixed choice of the hyperparameter imposes certain results on the amplitude and frequency, this parameter is estimated and, thus, tested for plausibility as well. From abstract point of view, the model posterior is investigated as well.

关键词： Bayes’ Theorem Linear Inversion Uncertainty monochromatic Spectral Limitation

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Internal and near-surface fields for a chiral sphere under arbitrary laser beam illumination

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Chinese Physics B 2019年第6期28卷 232-238页

作者： Bi-Da Su Ming-Jun Wang Yue Peng Su-Hui Yang Hua-Yong Zhang Department of Photoelectric Engineering Beijing Institute of TechnologyBeijing 100854China Science and Technology on Optical Radiation Laboratory Beijing 100854China School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China School of Electronics and Information Engineering Anhui UniversityHefei 230039China

A general scheme for the investigation of scattering by a chiral sphere under arbitrary monochromatic laser beam illumination is presented. The scattered and internal fields are expanded by using appropriate spherical vector wave functions, and their expansion coefficients are determined by the boundary conditions and the projection method. Targeting multiple incidence forms such as Gaussian beam, Hermite–Gaussian beam, doughnut mode beam and zero-order Bessel beam, the influence and propagation of near-surface intensity field for a chiral sphere are analyzed. These properties are very important for studying the properties of chiral media, and for manipulating the optical tweezers and super-resolution imaging of particles.

关键词： scattering chiral sphere monochromatic laser beamirradiation field intensity distribution

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List Vertex-arboricity of Planar Graphs without Intersecting 5-cycles

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Acta Mathematicae Applicatae Sinica 2020年第2期36卷 439-447页

作者： Wei-fan WANG Li HUANG Min CHEN Department of Mathematics Zhejiang Normal UniversityJinhua 321004China

The vertex-arboricity a(G)of a graph G is the minimum number of colors required for a vertex coloring of G such that no cycle is *** list vertex-arboricity al(G)is the list-coloring version of this *** this paper,we prove that every planar graph G without intersecting 5-cycles has al(G)≤*** extends a result by Raspaud and Wang[On the vertex-arboricity of planar graphs,European ***.29(2008),1064-1075]that every planar graph G without 5-cycles has a(G)≤2.

关键词： planar graphs list vertex-arboricity intersecting cycles monochromatic cycle

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Improvement of the Silicon Solar Cell Performance by Integration of an Electric Field Source in the Solar Cell or Solar Module System

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Smart Grid and Renewable Energy 2018年第12期9卷 285-298页

作者： Adama Ouedraogo Serge Dimitri Y. B. Bazyomo Salifou Ouedraogo Abdoul Razakou Dieudonné Joseph Bathiebo National Authority for Radiation Protection and Nuclear Safety Ministry of Environment of Burkina Faso Ouagadougou Burkina Faso Laboratory of Thermal and Renewable Energies Department of Physics Unit of Training and Research in Pure and Applied Sciences University of Ouaga 1 Prof. Joseph KI-ZERBO Ouagadougou Burkina Faso

This manuscript is about a theoretical modelling of conversion efficiency improvement of a typical polycrystalline Si solar cell in 1D assumptions. The improvement is brought by the increase of the collection of the minority carriers charge in excess. This increase is the consequence of the influence of an electric field provided by the use of the open circuit photovoltage of another silicon solar cell. We assume that it is integrated two silicon solar cells to the system. The first solar cell provides the open circuit photovoltage which is connected to two aluminum planar armatures creating a planar capacitor. The second solar cell is placed under the uniform electric field created between the two aluminum armatures. This work has shown an improvement of the output electric power leading to the increase of the conversion efficiency. We observe an increase of 0.7% of the conversion efficiency of the second silicon solar cell.

关键词： Open Circuit Photovoltage Planar Capacitor Electric Field Conversion Efficiency monochromatic Illumination and Silicon Solar Cell

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Degradation of Japanese Lacquer under Wavelength Sensitivity of Light Radiation

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Materials Sciences and Applications 2011年第10期2卷 1507-1515页

作者： Kosuke Nakagoshi Kunio Yoshizumi Kyoritsu Women\'s University Tokyo Japan.

Degradation of Japanese lacquer caused by light irradiation was examined at various wavelengths. By exposing lacquer specimens to a narrow monochromatic light band isolated from dispersed polychromatic light emitted by a Xe lamp source, the wavelength sensitivity characteristics of lacquer degradation could be determined on the basis of radiant energy. Tame-Urushi (brown) lacquer displayed peak degradation maxima at 220 and 315 nm. A broad shoulder peak was also observed in UVA. For Shu-Urushi (cinnabar) lacquer, in addition to peaks in the UVA–UVB range, a large degree of degradation was observed following exposure to light in the visible range. Ao-Urushi (green) lacquer showed similar characteristics, although it was less prone to degradation. Similarly, Shin-Urushi (black) lacquer showed little change in response to light, although UV light caused limited degradation. These results indicate that along with the damage caused by UVA and UVB, visible light in the range 510 - 650 nm may also have a significant degradation effect. Our results provide experimental evidence that Japanese lacquer responds differently to light of various wavelengths and that specific wavelengths, including visible light, can cause significant degradation.

关键词： Japanese Lacquer Degradation Wavelength Sensitivity monochromatic Light Spectral Reflectance Visible Light

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