Investigation of an Egyptian Mummy board by Using Clinical Multi-slice Computed Tomography     

Sveva Longo  Enricomaria Mormina  Francesca Granata  Domenico Mallamace  Marcello Longo  Silvia Capuani 《文物保护研究》2018,63(7):383-390

A modern approach to the diagnosis of artistic heritage makes use of non-destructive techniques which avoid damage to artworks or signs of interaction with the analytical technique used. For this reason, today, the employment of X-rays to study artistic heritage is quite widespread. Computed tomography (CT) Imaging was first used as specialized medical diagnostic tool in the early 1970s. Today, CT scanners have become more common, and non-destructive three-dimensional imaging has found an increasing number of uses in different areas such as materials research, geology, archaeology, and museum conservation. In this work, a new generation of clinical CT (based on the Dual Energy and multi-slice acquisition principle) is used to investigate an Egyptian wooden mummy board with a total acquisition time of 93.23 seconds and a voxel size of 0.078?×?0.078?×?1.5?mm. The use of two distinct techniques of image post-processing, the two-dimensional multi-planar reconstruction (MPR) and the three-dimensional volume rendering technique (VRT) allowed us to: evaluate the state of conservation of the mummy board, determine how the wooden object was implemented, recognize a nineteenth-century intervention of consolidation, and advance the hypothesis that the wooden planks were reused. In particular, we highlight the use of the cardiovascular and pulmonary filter with VRT reconstruction, which allows a virtual elimination of different parts of the mummy board to investigate those areas otherwise accessible only by removing parts of the board and thus damaging the work.  相似文献   

Measurement of conversion efficiency of soft X-ray from 0.35μm laser-irradiated aluminum planar targets     

Shu-xi Ren  Hong-liang Ma Ph. D.  Rong-qing Yi  Shen-ye Liu 《上海大学学报(英文版)》2006,10(3):224-227

Conversion efficiency of soft X-ray from 0.35 μm pulse laser-irradiated aluminium planar target at laser intensities 10¹³–10¹⁵ W/cm² on the Xingguang-II facility (laser energy 5–90 J, focal spot ⊃ Ф 200 μm full width of half maximun (FWHM) 400–800 ps) was measured. A simple model was given to explain soft X-ray conversion efficiency. In this model, because of the heat conduction from the laser-heated spot, the conversion was very small at lower irradiance limit, while at higher limit it was bounded by the energy lost in blow off plasma. Consequently, at the laser intensity around 2×10¹⁴ W/cm², the X-ray conversion efficiency reaches a maximum. Project suppoted by Shanghai Leading Academic Discipline Foundation (Grant No. T0104), and Science Foundation of Shanghai Municipal Commission of Education (Grant No. 214680)  相似文献   

Case Report:Lance-Adams syndrome:a report of two cases     

ZHANG Yan-xing    LIU Jian-ren  JIANG biao  LIU Hui-qin  DING Mei-ping  SONG Shui-jiang  ZHANG Bao-rong  ZHANG Hong  XU Bin  CHEN Huai-hong  WANG Zhong-jin  HUANG Jian-zheng 《Journal of Zhejiang University. Science. B》2007,(10)

Chronic post-hypoxic myoclonus, also known as Lance-Adams syndrome (LAS), is a rare complication of successful cardiopulmanry resuscitation often accompanied by action myoclonus and cerebellar ataxia. It is seen in patients who have un-dergone a cardiorespiratory arrest, regained consciousness afterwards, and then developed myoclonus days or weeks after the event. Worldwide, 122 cases have been reported in the literature so far, including 1 case of Chinese. Here we report 2 Chinese LAS patients with detailed neuroimagings. Cranial single photon emission computed tomography (SPECT) of patient 1, a 52-year-old woman, showed a mild hypoperfusion in her left temporal lobe, whereas patient 2, a 54-year-old woman, manifested a mild bilateral decrease of glucose metabolism in the frontal lobes and a mild to moderate decrease of the N-acetyl aspartate (NAA) peak in the bilateral hippocampi by cranial [18F]-fluorodeoxyglucose positron emission tomographic (PET) scan and cranial magnetic resonance spectroscopy (MRS), respectively. We also review the literature on the neuroimaging, pathogenesis, and treatment of LAS.  相似文献   

薄层CT动态扫描在诊断胰腺癌侵犯血管中的价值     

陈水泉  钟百书 《科技通报》1997,13(5):335-338

探讨了胰腺癌血管受累的ＣＴ分型与肿瘤手术可切除性的关系．对４３例经手术、病理证实的胰腺癌进行薄层ＣＴ动态扫描，根据确定的ＣＴ标准，观察肿瘤与血管的关系，并与手术结果对照．发现胰腺癌血管受累以Ｃ型最常见，占３７．２％，Ａ型１０例，肿瘤切除率１００％（１０／１０），Ｂ型９例，切除率为７７．８％（７／９），Ｃ型、Ｄ型２４例，均不可切除．表明薄层ＣＴ动态扫描能提高胰腺癌血管受累的诊断正确率，血管受累ＣＴ分型对外科制定手术计划具有一定价值．  相似文献   

Computed tomography using level set method and algebraic reconstruction technique     

薛倩  王化祥 《天津大学学报(英文版)》2011,17(6):418-423

In this paper, a novel reconstruction technique based on level set method and algebraic reconstruction technique is proposed for multiphase flow computed tomography (CT) system. The curvature-driven noise reduction method is inserted into the conventional iteration procedure of algebraic reconstruction technique to improve the image quality and convergence speed with limited projection data. By evolving the image as a set of iso-intensity contours after each updation, the sufficient number of iterations for acceptable results is reduced by 80%-90%, while the image quality is enhanced obviously. Quantitative evaluation of image quality is given by using both relative image error and correlation coefficient. The resultant images can be utilized to detect flow regimes for monitoring industrial multiphase flow. Laboratory results demonstrate the feasibility of the proposed method. Phantoms of four typical flow regimes can be reconstructed from few-view projection data efficiently, and the corresponding image errors and correlation coefficients are acceptable for the cases tested in this paper.  相似文献   

柴油机喷雾特性的电喷控制电路设计     

齐放  张乐超  许沧粟 《实验室研究与探索》2011,30(7):6-10

介绍了一种柴油机电控喷油器喷射开启控制系统。为实现柴油机电控喷油器的开启、持续喷油、关闭功能,应用STC12系列单片机构成电控喷油器的控制系统。开启时为使喷油器开启迅速,应用单周期控制技术的IR1150S芯片,产生高压为112 V的高压电源为喷油器供电。试验结果表明,开发的柴油机电控喷油器控制系统符合X光相衬成像技术研究柴油机喷雾雾化机理的要求,喷油开启迅速、喷油持续稳定、关闭干脆。本系统根据设定可实现电控喷油器的单次及多次连续开启,进一步可以推广应用于柴油机喷油器相关环节教学实验中。  相似文献   

Microanalytical identification of Pb-Sb-Sn yellow pigment in historical European paintings and its differentiation from lead tin and Naples yellows   总被引：1，自引：1，他引：0  

David Hradil  Tom&#x; Grygar  Janka Hradilov  Petr Bezdi ka  Veronika Gr&#x;nwaldov  Igor Foga&#x;  Costanza Miliani 《Journal of Cultural Heritage》2007,8(4):377-386

The work is focused on identification of lead tin yellow types I and II, Naples yellow, and also on discrimination of a less common, distinct yellow pigment, the ternary Pb-Sb-Sn oxide.The knowledge about all those Pb-based yellows was in fact forgotten after introduction of modern synthetic yellows in 19th century. As late as in the last decade of the 20th century, the existence of Pb-Sb-Sn yellow and its production have been rediscovered, and only then it has been identified in colour layer of artworks.Pb-Sb-Sn yellow has recently been identified in colour layer of 17th century Italian paintings by Sandalinas and Ruiz-Moreno [C. Sandalinas, S. Ruiz-Moreno, Lead tin-antimony yellow, historical manufacture, molecular characterization and identification in seventeenth-century Italian paintings, Stud. Conserv. 49 (2003) 41–52], and here we report the finding of this pigment in Mid-European painting of the 18th and 19th centuries. Lead tin yellows, lead antimony yellow (Naples yellow), and lead antimony tin yellow were synthesized in laboratory following historical recipes, their colour was analyzed, and their structure was confirmed to provide a basis for their routine identification in microsamples of artworks by X-ray microdiffraction. Unequivocal identification of Pb-based yellows could help in authentication of traditional European paintings, because their use was temporally and also geographically specific. Combination of elemental microanalysis (X-ray fluorescence electron microanalysis) and X-ray powder microdiffraction were found very efficient in the microanalysis of colour layers of artworks with Pb-based yellows and their unequivocal identification.  相似文献   

烧结温度对La_1.2Sr_1.8Mn₂O₇结构和磁性的影响     

东艳晖  赵旭  张彩霞  刘继宏  陈伟 《石家庄学院学报》2011,13(3):69-72

采用溶胶-凝胶法在不同的烧结温度下制备了La1.2Sr1.8Mn2O7多晶样品.磁性测量表明,1 200℃热处理的样品存在3个磁转变温度,且在116 K～365 K温区范围内磁化强度显著高于1 400℃热处理的样品;同时,1 400℃热处理的样品,在整个温区只存在2个磁有序转变温度,并且呈现出类自旋玻璃态.结合这2个样品的结构分析发现,较高温度处理更有利于双层钙钛矿结构的形成.  相似文献   

Digital body preservation: Technique and applications     

Vicky Vandenbossche  Joris Van de Velde  Stind Avet  Wouter Willaert  Stian Soltvedt  Noeska Smit  Emmanuel Audenaert 《Anatomical sciences education》2022,15(4):731-744

High-fidelity anatomical models can be produced with three-dimensional (3D) scanning techniques and as such be digitally preserved, archived, and subsequently rendered through various media. Here, a novel methodology—digital body preservation—is presented for combining and matching scan geometry with radiographic imaging. The technique encompasses joining layers of 3D surface scans in an anatomical correct spatial relationship. To do so, a computed tomography (CT) volume is used as template to join and merge different surface scan geometries by means of nonrigid registration into a single environment. In addition, the use and applicability of the generated 3D models in digital learning modalities is presented. Finally, as computational expense is usually the main bottleneck in extended 3D applications, the influence of mesh simplification in combination with texture mapping on the quality of 3D models was investigated. The physical fidelity of the simplified meshes was evaluated in relation to their resolution and with respect to key anatomical features. Large- and medium-scale features were well preserved despite extensive 3D mesh simplification. Subtle fine-scale features, particular in curved areas demonstrated the major limitation to extensive mesh size reduction. Depending on the local topography, workable mesh sizes ranging from 10% to 3% of the original size could be obtained, making them usable in various learning applications and environments.  相似文献   

Historical pigments characterisation by quantitative X-ray fluorescence     

《Journal of Cultural Heritage》2014,15(3):266-274

Most of the historical paints are mainly constituted by inorganic pigments, either pure or mixed, spread on the surfaces using different binding agents. The knowledge of the exact amount of different constituents of the paint, as well as of the mixing and pictorial techniques, is crucial for a careful program of conservation of polychrome works. Moreover, since the availability of these pigments has been changing through the centuries, their identification and chemical characterisation is useful to acquire or deepen information about the artist and his/her work. This information can also be useful for authentication purposes through relative dating because the identification of one pigment respect to another one can be used as a terminus post quem or ante quem the artwork was realized. In this work, X-ray fluorescence data from historical pigments, both pure and mixed, will be presented, in order to obtain quantitative information on the samples and to extract calibration curves to the aim of evaluating the pigment concentration in unknown mixtures.  相似文献