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

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.     

光学分层成像法重建火焰温度场的理论和实验研究

提出了一种测量三维火焰温度的新方法 .根据光学分层成像理论 ,三维火焰可以看成若干个互相平行的二维发光断层的组合 .用高速摄像控制系统沿着某一固定方向对火焰进行分层聚焦摄像 ,得到一组辐射图像 ,每个图像都是其对应断层的聚焦像和其它断层离焦像的叠加像 ,运用图像反演算法 ,即可重建各断层的原始图像 ,再用彩色三基色测温方法 ,处理所得到的原始图像 ,即可建立火焰的三维温度场 .通过蜡烛火焰的试验 ,验证了该方法的可行性     

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

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)     

Ultrasonic tomography and its applications in oilfield

INTRODUCTION Oil and water well is an important basic estab- lishment in oilfields. In many oilfields, there are many different damages in the well’s casing walls after its development for a period of time. They will affect the normal production of damaged wells and adversely influence the neighbouring wells and the block, and threaten steady production. There are different kinds of damages due to multiple problems in the casing walls, for example, corrosion, perforation, decreased diame…     

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

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.     

薄层CT动态扫描在诊断胰腺癌侵犯血管中的价值

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．     

Computed tomography using level set method and algebraic reconstruction technique

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.     

柴油机喷雾特性的电喷控制电路设计

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。     

YBa2Cu3-x GdxO7-δ的X射线衍射研究

用传统的固相反应法制备了掺杂稀土元素Gd的YBa2Cu3-xGdxO7-δ多晶粉末样品,并对YBa2Cu3-xGdxO7-δ结构进行X射线衍射研究。详细研究了Gd掺杂对YBa2Cu3O7-δ(Y-123)的结构与输运性质的影响。借助Rietveld方法,对不同掺杂的样品进行了细致的结构分析,并从结构的变化分析了掺杂对自旋隙产生的影响。对Gd3 离子磁掺杂自旋隙特征的研究说明自旋隙温度很大程度地依赖平面间的反铁磁关联配对的加强。     

分峰计算结晶度的问题探讨

应用分峰方法计算结晶度,首要条件是结晶聚合物的形态结构必须符合"两相模型"。通过聚合物材料的分析,发现Jade软件的分峰程序固然很好,但其受到扫描范围、基线、非晶峰位置及分布的影响很大,计算的结晶度值有一定的随意性,只能作相对比较,且结晶度值偏大。用X射线衍射法测定的结晶度与其他实验方法获得的结晶度无可比性,还常遇到背景散射的基线不平和非晶峰难以确定等现象。对此进行探讨和交流。