摘要：针对肺部x-ray图像在超分辨率重建过程中出现的肺部边缘不清晰以及器官纹理模糊等问题,提出一种基于多级残差注意力的x-ray图像超分辨率重建方法。将注意力机制嵌入残差块中构建网络基本块,在加速网络收敛的同时,使网络更加关注图像的边缘纹理特征;设计多尺度特征融合模块进行特征提取,保证结构信息的完整性;通过多级残差学习加速网络训练,并允许构建更深层次的网络;融合上采样图像与Bicubic图像完成最终重建,弥补特征提取过程中的特征损失。实验结果表明,所提出模型的PSNR、SSIM均高于现有算法,且重建出的图像具备更加丰富的细节和清晰的边缘。

摘要：A readout system for x-ray CCDs based on an improved architecture is presented; by optimizing several critical circuit blocks along the analog signal chain, the conflict between the readout speed and readout noise is greatly alleviated. Using CCD47-10 as its target CCD, the readout system has achieved 8.6e^- readout noise and 142 eV FWHM at 5.9 keV Mn Kα under a pixel rate of 80 kHz. Also its performance of imaging has been investigated.

摘要：The surface topography of acetabular implants plays a key role in providing cell attachment and *** measurement and characterisation of the surface texture of the cellular scaffold layer on the acetabular cup are very difficult due to the 3D nature of scaffold *** is proposed to use x-ray computed tomography(xCT)to measure the surface texture of an electron beam melting-produced titanium acetabular *** surface texture of its cellular scaffold is evaluated using the newly developed 3D surface texture parameters,which allows surface characterisation on 3D triangular mesh *** commonly used height parameters,*** arithmetical mean height Sa,the root mean square height Sq,the skewness Ssk and the kurtosis Sku,are calculated from surface patches extracted from the xCT scanned triangular mesh *** addition,the surface peak density and pit density,which are more related to cell communication and proliferation,are estimated based on the 3D watershed *** Wolf pruning with an empirical threshold 12μm is used to control the over-segmentation.

摘要：In the applications of neutron guides and focusing devices, by using the Ni/Ti multilayer supermirrors （SM）, the neutron flux is significantly enhanced, because the critical reflective angle of supermirrors increases m times compared to the one of natural bulk Ni. We design and fabricate the Ni/Ti multilayer supermirrors by considering the effect of the interfacial imperfection, such as interface roughness and diffusion, and by using the direct current magnetron sputtering technology. The reflective performances of these supermirrors are measured on a V14 neutron beam line at the Berlin Neutron Scattering Centre （BENSC）, Germany. The measurement data suggest that the critical angles of the supermirrors are 1.5 and 2.2 times that of bulk Ni, respectively.

摘要：Beijing Synchrotron Radiation Facility is a partly dedicated synchrotron radiation source operated in either parasitic or dedicated mode. The 3B1A beamline, extracted from a bending magnet, was originally designed as a soft x-ray beamline for submicro x-ray lithography with critical lateral size just below 1μm in 1988 and no change has been made since it was built. But later the required resolution of x-ray lithography has changed from sub-micrometre to the nanometre in the critical lateral size. This beamline can longer more meet the requirement for x-ray nano lithography and has to be modified to fit the purpose. To upgrade the design of the 3B1A beamline for x-ray nano lithography, a mirror is used to reflect and scan the x-ray beam for the nano lithography station, but the mirror's grazing angle is changed to 27.9mrad in the vertical direction, and the convex curve needs to be modified to fit the change; the tiny change of mirror scanning angle is firstly considered to improve the uniformity of the x-ray spot on the wafer by controlling the convex curve.

摘要：The article is to study the development of computer-aided design of x-ray microtomography—the device for investigating the structure and construction of three-dimensional images of organic and inorganic objects on the basis of shadow projections. This article provides basic information regarding CAD of x-ray microtomography and a scheme consisting of three levels. The article also shows basic relations of x-ray computed tomography, the generalized scheme of an x-ray microtomographic scanner. The methods of x-ray imaging of the spatial microstructure and morphometry of materials are described. The main characteristics of an x-ray microtomographic scanner, the x-ray source, x-ray optical elements and mechanical components of the positioning system are shown. The block scheme and software functional scheme for intelligent neural network system of analysis of the internal microstructure of objects are presented. The method of choice of design parameters of CAD of x-ray microtomography aims at improving the quality of design and reducing costs of it. It is supposed to reduce the design time and eliminate the growing number of engineers involved in development and construction of x-ray microtomographic scanners.

摘要：研究了在Λ型三能级类氦碳离子C^(4+)体系中波长为4.03nm的x-ray超辐射的产生,探讨了紫外波段的相干光场的耦合作用对x-ray超辐射产生的量子相干调控.通过数值模拟离子间和离子内部的干涉效应,发现控制离子密度和耦合相干光场强度可以实现对超辐射的脉冲强度和脉冲分裂特征的调控.当驱动光场的Rabi频率由4.3"10^(13)Hz增加到1.7"10^(14)Hz时,出射脉冲的最大输出强度增加约150倍.随着驱动光场Rabi频率的增加,最大脉冲输出强度呈现收窄震荡趋势.其结果对设计x-ray源具有潜在的应用价值.

摘要：设计AC-13C、SMA-13、SAC-13和AR-AC-13S等4种常用级配的橡胶沥青混合料,通过xray CT技术和图像处理技术获取橡胶沥青混合料内部结构中的空隙分布数值参数,分析4种级配的混合料细观特征,结果表明：四类级配的空隙分布各有特点,连续级配的内部空隙比间断级配更少,内部密实度更好,应能用于橡胶沥青混合料;在混合料内部空隙特征方面,表现最为良好的是SAC-13,其次是AC-13C,SMA-13和AR-AC-13S的表现相似。

摘要：为分析定向钢纤维混凝土中钢纤维的分布,通过x-CT扫描原位测试确定了混凝土中所有钢纤维的空间位置坐标,根据钢纤维空间坐标,分析计算钢纤维的角度分布及纤维方向效应系数。结果表明,定向钢纤维混凝土中,与设计的目标方向夹角<30°的钢纤维根数占总数量的比例达85%,定向钢纤维的定向效果较好;定向钢纤维混凝土中纤维方向效应系数增加25%,增强效率显著提高。

摘要：利用x-ray CT技术,获取沥青混合料内部结构组成,分析体积参数,进而完成沥青混合料的计算机辅助设计的研究已成为沥青路面技术领域的关注热点.重点介绍了在利用x-ray CT进行沥青混合料体积组成分析与差异性物质辨识、混合料内部结构组成的三维图像重构、沥青混合料性能的虚拟试验等方面研究时存在的问题和可能的解决方法.同时,提出了进一步研究所需要解决的一些关键技术,给出了一个技术路线图以供日后的研究参考.