拉曼光谱在咪唑斯汀缓释片晶型鉴别中的应用

固体制剂多晶型药物仿制药一致性评价研究工作中,需对自制制剂和参比制剂中主药晶型的一致性进行研究。咪唑斯汀缓释片中主药含量占比低于5%,且辅料组分乳糖对主药晶型分析具有干扰,单独采用X射线粉末衍射法进行制剂晶型分析难度较大。本文采用拉曼光谱法,辅以X射线粉末衍射法对咪唑斯汀缓释片中咪唑斯汀的晶型进行鉴别。应用拉曼成像的方法,定位活性成分在缓释片制剂中分布较为集中的区域,再采用单点检测,精准采集制剂活性成分拉曼信号。将经X射线粉末衍射法确证为Form A的原料药进行拉曼单点检测,并与制剂中活性成分的拉曼信号进行对比。结果显示,自制咪唑斯汀缓释片中主药为Form A,且与原研制剂一致。证明本方法在制剂中主药含量低且辅料对主药X射线衍射分析有干扰的晶型鉴别中具有应用价值。     

中药材栀子的X射线衍射傅立叶指纹图谱鉴定研究

为建立一种新的中药材鉴定与分析方法,我们采用粉末X射线衍射分析技术,分别对19个不同来源的栀子样品进行实验分析研究。利用粉末X射线衍射傅立叶(Fourier)指纹图谱分析方法,获得栀子与水栀子等中药材的各自对照衍射图谱和特征标记峰值。使用对照衍射图谱和特征标记峰值可以很好地区分道地中药材栀子、药材栀子变种-水栀子及地方习用品-黄花栀子。分析结果表明,粉末X射线衍射Fourier指纹图谱分析方法可以用于传统中药材的鉴定与质量控制。     

新型X射线粉末衍射仪高级功能应用研究

本文介绍了德国布鲁克公司新一代的X射线粉末衍射仪"D8 ADVANCE with DAVINCI design"的光源、测角仪、光路系统、探测器和应用软件,并对该仪器进行功能开发应用研究。测试表征了介孔材料SBA-15的小角衍射,并与"NanoSTAR X射线小角散射系统"测试的结果进行对比;测试了3种纤维样品的取向度;通过X射线反射(XRR)测定多层膜,并使用Leptos软件进行了拟合,得到了各层膜的厚度、粗糙度及密度;通过测定单晶样品的摇摆曲线来确定单晶样品的晶面;最后简要介绍了对分布函数(Pair Distribution Functions(PDF))的测定及计算。通过对这些非常规的测试及表征,开发了该仪器的功能。     

石化装置堵塞物中晶体定性分析

采用粉末X射线衍射法(XRPD)定性分析一石化装置堵塞物样品中的主要晶体成分。实验结果表明:本法对该石化装置静设备堵塞故障技术分析及技改具有重要的现实指导意义。     

X射线衍射揭示粉末物质内部结构

本文的第一部分（见Instrumenta25（9）16）评述科研人员通过对单晶衍射（SCD）的技术改进,使其成为实验室中常规的科研工具。然而,SCD技术的巨大进步还体现在粉末X射线衍射（XRD）方面。粉末X射线衍射是一种非破坏性的、可以揭示粉末物质内部结构的强大技术,它不仅可以应用于实验室,而且也可以应用于过程控制和产品检验等方面。     

×射线衍射揭示粉末物质内部结构

本文的第一部分(见Instrumenta 25(9)16)评述科研人员通过对单晶衍射(SCD)的技术改进,使其成为实验室中常规的科研工具.然而,SCD技术的巨大进步还体现在粉末X射线衍射(XRD)方面.粉末X射线衍射是一种非破坏性的、可以揭示粉末物质内部结构的强大技术,它不仅可以应用于实验室,而且也可以应用于过程控制和产品检验等方面.     

X射线衍射法研究药物多晶型应用进展

药物常见的固态形式有溶剂化物、亚稳定型、无定型和共晶型,这些不同的存在形式影响着药物的溶解度、溶出速率、生物利用度等,有的甚至引发毒副作用,关系着药物的临床疗效.因此,对药物多晶型的研究是进行药物质量控制和管理的重要内容,广受医药研发和管理领域的关注.本文着重综述了单晶X-射线衍射法和粉末X-射线衍射法在药物多晶型研究中的应用进展.     

用于材料科学研究的新产品——X′Pert-MRD材料研究衍射仪

<正> 1.绪论 X Pert—MRD材料研究衍射仪是飞利浦公司X射线分析部迄今推向市场的X射线衍射仪中功能最齐全的机型。为材料科学家提供了拓展研究领域的新机遇。它的设计是结合先进技术的典范,集多功能于一台仪器,其应用之灵活和使用之方便无于伦比。在几分钟内便可实现点与线聚焦的互换和多种应用光系统的互换,不必再装卸复杂的光学系统和重新校准。初学者也能掌握高分辨率的测量晶体,和Ω残余应力,结构、薄膜衍射、反射率和物相分析,一定会获得一流的实验结果。     

X射线多重衍射效应

本文介绍了X射线多重衍射效应的起因,多重衍射图谱的指标化,给出了用普通X射线粉末衍射仪观测多重衍射效应的方法,并简要说明了多重衍射效应的应用。     

多晶X射线衍射仪的技术进展

简要介绍了近几年来多晶X射线衍射仪的光源、测角仪、样品台、光学系统、附件、检测器和应用软件方面的技术进展和用途扩展情况。     

Differential interference contrast and confocal reflectance imaging of collagen organization in three-dimensional matrices

The remodeling of extracellular matrices by cells plays a defining role in developmental morphogenesis and wound healing as well as in tissue engineering. Three-dimensional (3-D) type I collagen matrices have been used extensively as an in vitro model for studying cell-induced matrix reorganization at the macroscopic level. However, few studies have directly assessed the process of 3-D extracellular matrix (ECM) remodeling at the cellular and subcellular level. In this study, we directly compare two imaging modalities for both quantitative and qualitative imaging of 3-D collagen organization in vitro: differential interference contrast (DIC) and confocal reflectance imaging. The results demonstrate that two-dimensional (2-D) DIC images allow visualization of the same population of collagen fibrils as observed in 2-D confocal reflectance images. Thus, DIC can be used for qualitative assessment of fibril organization, as well as tracking of fibril movement in sequential time-lapse 2-D images. However, we also found that quantitative techniques that can be applied to confocal reflectance images, such as Fourier transform analysis, give different results when applied to DIC images. Furthermore, common techniques used for 3-D visualization and reconstruction of confocal reflectance datasets are not generally applicable to DIC. Overall, obtaining a complete understanding of cell-matrix mechanical interactions will likely require a combination of both wide-field DIC imaging to study rapid changes in ECM deformation which can occur within minutes, and confocal reflectance imaging to assess more gradual changes in cell-induced compaction and alignment of ECM which occur over a longer time course.     

X射线聚焦望远镜镜片黏接装配的数值模拟和分析

对采用圆锥嵌套Wolter-I型结构的X射线聚焦望远镜在装配过程中产生的面形偏差进行了模拟和分析。首先,利用ANSYS有限元软件建立二维模型。然后,以实际装配步骤和夹具为加载和边界条件,通过分析不同半径镜片的装配过程,得到了面形偏差与三根压条的载荷关系曲线,由此优选出了不同半径镜片对应的最佳装配载荷。分析显示:除对应的最大面形偏差外,优选出的装配载荷均可控制在0.1μm以内,满足装配精度要求,而且对应装配载荷下玻璃镜片的最大Mises应力也均小于玻璃的强度极限,不会在装配过程中失效。此外,建立了三维分析模型并与二维简化模型分析结果进行了比较。结果显示:计算偏差主要集中在镜片的前、后两端约5mm范围内,最大偏差为2.3μm;镜片中段两种模型的计算偏差小于0.03μm,表明提出的二维简化模型可以用于玻璃镜片装配的快速面形偏差分析和载荷确定。文中对镜片装配过程的分析可为提高装配精度提供理论依据。     

CAXA实体设计在新产品设计中的应用

应用CAXA实体设计灵活的可视化拖放技术和参数化设计,并通过精确化的方法进行动态修改,可以迅速地将一个产品的雏形模糊概念,变成逼真的三维实体,真实地反映产品的结构组成以及各零部件的相互关系。CAXA实体设计还可以进行运动模拟、干涉检查和拆装模拟;为后续的分析、数控加工提供三维数字模型,实现无纸化生产。另外还能方便地生成带有轴测图的二维装配图、零件图。当对产品的设计修改时,使用尺寸关联,相关零部件的结构、尺寸同时修改,有利于产品的更新换代和系列化。     

磨粒三维表面形貌的研究分析

磨粒三维表面形貌分析是针对磨粒二维分析技术的不足而提出的磨粒分析方法。分析了目前磨粒三维表面形貌获取技术特点和实用性,探讨了近年来磨粒表面形貌三维表征描述中采用的几种方法——灰度共生矩阵、分形维数法、方向测度法,并通过分析表明,方向测度法是一个比较好的磨粒表面形貌三维特征分析方法。     

Three-dimensional microscopy data exploration by interactive volume visualization

This paper presents a new volume visualization approach for three-dimensional (3-D) interactive microscopy data exploration. Because of their unique image characteristics, 3-D microscopy data are often not able to be visualized effectively by conventional volume visualization techniques. In our approach, microscopy visualization is carried out in an interactive data exploration environment, based on a combination of interactive volume rendering techniques and image-based transfer function design methods. Interactive volume rendering is achieved by using two-dimensional (2-D) texture mapping in a Shear-Warp volume rendering algorithm. Image processing techniques are employed and integrated into the rendering pipeline for the definition and searching of appropriate transfer functions that best reflect the user's visualization intentions. These techniques have been implemented successfully in a prototype visualization system on low-end and middle-range SGI desktop workstations. Since only 2-D texture mapping is required, the system can also be easily ported to PC platforms.     

Image processing techniques for 3-D chromosome analysis

3-D karyotype analysis is developing rapidly due to the availability of confocal microscopes and CCD video cameras, and the development of 3-D processing techniques. Here, image enhancement and visualization techniques specifically designed for 3-D karyotype analysis are described. To facilitate a good comparison between the different techniques, the same 3-D image, obtained with a confocal scanning laser microscope (CSLM), of a mitotic prophase nucleus of a root-tip cell of Crepis capillaris was used throughout. Besides well-known stereoscopic presentation, another means of improving depth perception is shown, i.e. a solid modelling algorithm, which simulates the process of fluorescence. An interactive routine to dissect objects in the image is presented as an alternative for automated segmentation algorithms, which cannot be applied to closely apposed or merging objects. As an example of a convenient way to reduce the vast amount of data (2 Mbyte per image), a partly automated 3-D cursor is presented in detail. This cursor is used to trace the central axes of chromosomes and record them as strings of Cartesian coordinates. The advantages of a computer graphics display, which facilitates real-time rotation and hence is a powerful tool in studying 3-D features of chromosomes, are also shown.     

The surface layer of friction plastics

The tribological problems of plastics used for friction brakes with particular emphasis on the design problems of materials with optimal characteristics for the working conditions of shoe brakes for underground railways were investigated. The phenomena associated with the friction and wear of these materials were identified by examining the surface layers of samples using the following techniques: optical and scanning electron microscopy, X-ray microanalysis and thermogravimetric analysis at temperatures up to 1270 K. A model of the structure of the surface layer of friction materials was developed. It consists of five layers which differ in composition, structure and properties. This model is important in the development of new friction materials with specified tribological characteristics.     

Integrated approach for segmentation of 3-D confocal images of a tissue specimen

In this article we have proposed an integrated approach for segmentation of cells in volumetric image data obtained using the Confocal Microscope. The volumetric images are the stack of two-dimensional (2-D) images. Segmentation of cells in such an image stack is a difficult problem due to the complex structure of the objects and the spatial relationship of the object signatures in different image slices of the image stack. Here we have proposed a segmentation technique, which is a combination of several known and novel segmentation methods. Low-level techniques such as edge operators, middle-level techniques such as 3-D watershed, rule-based merging, and a high level technique, active surface model optimization, are integrated in one approach to get better segmentation with less human interaction. Some image enhancement and noise reduction techniques are also used to reduce the error in intermediate stages and speed up the segmentation process. Results are shown on 3-D images of prostate cancer tissue specimen.     

Review of the finite element models for a structural integrity evaluation of the sodium-cooled fast reactor high temperature piping

We compared the structural analysis feature of finite element (FE) models for the structural integrity evaluation of the sodium-cooled fast reactor (SFR) high temperature piping and to evaluate the structural integrity against the typical duty cycle event. To evaluate the structural integrity of the high temperature piping per ASME Subsection NH rules, the structural analysis should be carried out first by using a 3-dimensional structural model. The object FE models under consideration in this study are pipe element model, 3-D full model, and 3-D simplified model. The pipe element model is based on the 3-D beam element and effective in understanding overall deformation but less favorable to the detailed stress distribution. The 3-D full model consists of solid structure as well as the contained coolant inside the piping structure with the fluid element. The 3-D simplified model consists of structure shape only, but its material properties are recalculated to reflect the coolant weight effect. The loading conditions for the structural analyses are the mechanical load including dead weight and steady state thermal load. From the analysis results, the piping element model shows the smallest stress intensity, and the required time for FE analysis is also the shortest. The 3-D simplified model shows the most conservative stress intensity output but its calculation time is less than the 3-D full model.     

Reliability analysis of a flexible machining cell

Introduction of flexible machining systems incorporating robotic manipulators for high speed transfer of tools and workpieces entails high capital investment. This is an important constraint which limits the scope for experimentation and emphasises the importance of reliability as a deciding factor in the use of such systems. This paper describes a typical flexible machining cell configuration. Operational details relating to its elements and their components are included. A large amount of data concerning the failure characteristics of various subsystem elements are gathered and processed. Using a representative sample, qualitative and quantitative analyses of the system reliability are carried out using various reliability evaluation techniques. These include block diagram analysis (BDA), fault tree analysis (FTA) and a discrete Markov model. In particular attention is paid to the availability of the robot-assisted tool delivery system, including sensing, measuring and signal conditioning devices.