感绿医用X线胶片感光度测定时施照光光度谱成分探讨

新颁布的测定医用Ｘ线胶片感光度的国际标准规定,用Ｘ－射线作为感光测定曝光时的光源,此法精确,但所需设备复杂,操作耗时。因此,在日常的检测工作中,采用特定的可见光代替Ｘ线射线为感光测定时曝光的施照光,是实施而合理的方法,本文介绍一组绿色可见光,可适用于测定感绿医用Ｘ线胶片的感光度。     

用感光仪绿色施照测定感绿医用X线胶片时感光度的计算

本文阐明了用特定谱可见光对感绿医用Ｘ线胶片进行感光测定时，以能量线物理绝对单位焦耳／平方米为单位计量曝光量的计算方法和依据，以求取感光度。     

铱盐在工业射线胶片中的应用

本文阐述提高工业射线胶片拍摄宽容度和射线感光度的研究。尽管我们一般的工业射线胶片与国外名牌产品对可见光具有相同的感光速度,但是实际上用X-射线曝光对较厚钢管和铸件进行无损探测时,感光速度却远低于国外工业射线胶片,这是由于在用低照度长时间曝光时产生的互易律失效现象造成的。研究结果证实:在乳剂制备过程中加入铱盐作为掺杂剂,可提供多价离子在卤化银颗粒的适当位置产生浅电子陷阱,以防止出现互易律失效现象,从而全面改进工业射线胶片的感光性能。     

用感光仪绿色施照光测定感绿医用X线胶片时感光度的计算

本文阐明了用特定光谱可见光对感绿医用X线胶片进行感光测定时 ,以能量纯物理绝对单位焦耳 /平方米为单位计量曝光量的计算方法和依据 ,以求取感光度。     

工业射线照相胶片的感光特性、质量与选用要求

１工业无损检测对象与相关要求（见上期）２胶片感光性能要求（见上期）２．１层次特性（见上期）２．２能谱特性在实用范围内，X射线胶片特性曲线的形状不受照射到胶片上的X射线或γ射线波长（或能量）的影响。但胶片的感光度，就获得一定黑度所需要的照射量———伦琴数而言，会受到照射线能量（或波长）的强烈影响。图５表示某种胶片在一定的冲洗条件下获得黑度１．０所需要的射线照射量伦琴数（曝光时不用增感）。各种X射线胶片的能谱感光度曲线与图５所示曲线特点大致相同。但一种胶片与另一种胶片的感光性能，特别是最大感光度与最…     

用屏片组合法测定医用X线性能及在放射摄影中的应用

用屏片组合法测定医用Ｘ线性能及在放射摄影中的应用上海感光材料公司一分厂汪永明上海静安区中心医院曹厚德众所周知，医用Ｘ线胶片使用时是在其两面夹以增感屏，用Ｘ线照射。国际标准规定的曝光方法是用Ｘ线直接曝光’‘’；而我国标准则规定用可见光曝光，感光度和平均...     

几种医用X线胶片的屏片组合感光性能测试及其在尘肺摄片中的应用

本文介绍应用自举法（Bootstrap）以X射线对五种国内外医用X线胶片和荧光屏组合进行感光性能测试的方法和结果。根据测试数据计算出每种胶片的恰当曝光时间,然后对尘肺病人摄片,得到符合诊断要求的X线照片。     

加工方法对X线胶片屏片组合性能的影响

１　前言已经知道,用可见光曝光测定Ｘ线胶片性能时,加工方法对胶片的性能是有影响的［１］。而用Ｘ射线直接曝光法测定Ｘ线胶片性能时,也与加工方法有关。在国际标准ＩＳＯ５７９９－１９８１（Ｅ）中没有说明加工方法,但指出,得到的感光度和平均斜率与加工所用药品、每一步加工的时间、温度、搅拌、设备和程序有关。不同的加工程序所得到的感光度和平均斜率差异是很大的。因此,在该标准的附录Ｂ中,对手工加工的药品标准、显影和定影工艺均作了规定［２］。用屏片组合法测定Ｘ线胶片性能时,国际标准ＩＳＯ９２３６－１中也没有说明…     

关于医用X线胶片感光测定时辐射能的标准和计算

本文扼要地介绍了医用X线胶片感光测定时,用于使胶片曝光的几种辐射能标准,阐述了其技术背景、特点及曝光能量计量单位和有关计算。     

彩色胶片的性能(二)

(三)感光度S 1.感光度S:感光度表示胶片感光快慢的程度,是摄影时,决定曝光组合的条件之一。它以底片上达到一定的密度所需的曝光量的多少为依据,所需的曝光量愈少,胶片的感光度愈高,反之,感光度低。 1979年,国际标准化组织(ISO)通过了彩色照相底片感光度的测定标准。标准规定,胶片按推荐的加工条件冲洗,以D_0+0.15作为基准密度点(灰雾密度以上0.15的     

Analytic solution for separating spectra into illumination and surface reflectance components

The measured light spectrum is the result of an illuminant interacting with a surface. The illuminant spectral power distribution multiplies the surface spectral reflectance function to form a color signal--the light spectrum that gives rise to our perception. Disambiguation of the two factors, illuminant and surface, is difficult without prior knowledge. Previously [IEEE Trans. Pattern Anal. Mach. Intell.12, 966 (1990); J. Opt. Soc. Am. A21, 1825 (2004)], one approach to this problem applied a finite-dimensional basis function model to recover the separate illuminant and surface reflectance components that make up the color signal, using principal component bases for lights and for reflectances. We introduce the idea of making use of finite-dimensional models of logarithms of spectra for this problem. Recognizing that multiplications turn into additions in such a formulation, we can replace the original iterative method with a direct, analytic algorithm with no iteration, resulting in a speedup of several orders of magnitude. Moreover, in the new, logarithm-based approach, it is straightforward to further design new basis functions, for both illuminant and reflectance simultaneously, such that the initial basis function coefficients derived from the input color signal are optimally mapped onto separate coefficients that produce spectra that more closely approximate the illuminant and the surface reflectance for any given dimensionality. This is accomplished by using an extra bias correction step that maps the analytically determined basis function coefficients onto the optimal coefficient set, separately for lights and surfaces, for the training set. The analytic equation plus the bias correction is then used for unknown input color signals.     

我国医用X线胶片的前景探讨

随着直接数字射线照相DDR、计算机射线照相CR、成像版IP等新成像技术在医学成像界的逐步推广应用,传统的X线胶片,包括各种感兰片、感绿片、CT片等的市场已逐步被这些新成像系统产品所占据,在我国的大城市,有些医院（如上海瑞金医院）已经把X线成像的相关工作,包括：照相、诊断、交流、存档、检索、教学、研究全部数字化,不使用胶片了;尽管如此,由于我国广大农村人口卫生保健全面改善的实际需要和支付水平,以及传统医用X线胶片和成像设备的较低价格,胶片仍然还在广泛使用,因此我国最近几年的医用X线胶片的消费量还是在逐步增长,而且预计今后还要继续增长。本文以海关的进出口数据和对医院就诊人数的统计,进行全面分析说明这个问题。     

Determining thin film parameters by prism coupling technique

A new method for determining the absorption coefficients, refractive indices, and thicknesses of thin films is proposed. The method is based on the measurement of the angular dependence of the energy reflection coefficient of a light beam upon excitation of the waveguide or leaky modes by a prism coupler. The features of determination of the parameters of SiO_x films on silicon and glass substrates are considered.     

Investigation of the interfacial structure of ultra-thin platinum film deposited by cathodic–arc

Ultra-thin films are of interest in the production of X-ray mirrors that use a multilayer structure. The most commonly used deposition techniques are dc magnetron sputtering and electron beam evaporation; this paper presents results of cathodic–arc deposition. Ultra thin films of platinum with nominal thicknesses in the range 15–65 Å were deposited on silicon substrates and the film structure investigated using X-ray reflectivity and X-ray photoelectron spectroscopy. It has been found that the structure of the deposited films consists of three layers—the platinum film, a silicon oxide layer and a platinum silicide layer. In contrast to dc magnetron and electron beam deposited films, the silicide layer of cathodic–arc deposited films have a higher density and greater thickness, which is attributed to the higher energy process of this deposition technique. These attributes of the cathodic–arc deposited films suggest that the deposition technique is not suitable for production of mirrors of materials that react with each other, but for materials that do not the deposition technique is potentially more favourable than that of e-beam and magnetron sputtering.     

离子束增强反应磁控溅射低温快速沉积AlN膜

本文采用氮离子束增强反应磁控溅射,在低温下沉积了 AlN 薄膜.用 X 射线衍射和 X 射线光电子谱对薄膜的晶体结构和电子结构进行了分析,结果表明,随着离子源中氮离子束流的增加,薄膜组成由面心立方的 Al 转变为密排立方的 AlN.氮离子在薄膜制备中的引入,有效地降低了沉积温度,提高沉积速率,并实现了薄膜 N/Al 化学计量比的控制.对 AlN 薄膜的紫外-可见光透射谱和红外吸收谱也进行了测定.     

Compositional and morphological analysis of AgCl films deposited by evaporation and R.F. sputtering

AgCl thin films in a range of thicknesses from 0.05 to 2 μm were deposited by evaporation and r.f. sputtering of AgCl as well as by co-evaporation of AgCl and silver. Their structure and composition were studied using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy, energy-dispersive X-ray analysis and optical absorption spectroscopy. Films grown by evaporation show a preferential grain orientation that depends on the deposition rate. They are stoichiometric except for chlorine enrichment at the surface, but exposure to an electron beam or UV light causes metallic silver formation. AgCl films grown by r.f. sputter deposition have greater surface roughness than those grown by evaporation, a random grain orientation and a grain size that depends on the sputtering conditions. Metallic silver is present in these films. Optical absorption measurements of co-evaporated films suggest that the metallic silver occurs in two forms, small dispersed particles in the AgCl matrix and larger particles at the grain boudaries.     

Path of a beam of light through an optical coating

A simple model for the path of a light beam through an optical coating is the path of a ray predicted by Snell's law. By determining the exit point of a beam for various types of coating, one finds that the simple model is a good approximation in the case of antireflection coatings, but not for coatings of other designs. An approximate method for determining the correct path of a beam through the coating is derived and the path is illustrated using a Gaussian incident beam and tracing the position of the peak field of the beam as it traverses the coating.     

Transfer of molybdenum sulphide coating material onto corundum balls in fretting wear tests

Transfer films on corundum balls from sulfur deficient molybdenum disulfide (MoS_x) coatings with different crystallographic orientations were investigated after fretting tests performed in ambient air of different humidity levels. The morphology of wear tracks on MoS_x coatings and of transfer films on corundum balls were investigated by light optical microscopy with Normarski contrast. The thickness of transfer films was measured by scanning white light and optical phase-shifting interferometry, and their composition was analyzed by X-ray photoelectron spectroscopy. The effect of relative humidity in fretting tests on the composition of the transfer films as well as the effect of the transfer film on the tribological performance of MoS_x coatings in fretting wear tests is discussed.     

High-resolution chemical imaging through tissue with an X-ray scintillator sensor

We describe a novel method for high-resolution chemical imaging on a surface embedded in tissue. The sensor surface consists of an X-ray scintillator film coated in a thin film loaded with chemical indicator dye. A narrow scanning X-ray beam is used to excite luminescence from X-ray scintillators located within the beam. This luminescence passes through the indicator film, and the spectrum is analyzed to measure chemical concentrations at that location. A pH sensor is demonstrated with a dynamic range between pH 6-9 and noise level of 0.05 pH units using methyl-red dyed pH paper. The location of the interface between two types of scintillator films is obtained with 0.30 mm spatial resolution even though the images are highly blurred by 10 mm of chicken breast. This work has important applications for detecting pH changes on surfaces of implanted medical devices.