zeolites a, x and hs were synthesized from natural iranian kaolinite by alkaline fusion,,followed by refluxing the mixture. the transformation of zeolites x to hs and y to p were studied at different time intervals by x-ray diffraction and scanning electron microscopy (sem). it was revealed that in solution, zeolites hs and p are more stable than zeolites x and y respectively

Coherent x-ray diffraction imaging is an x-ray microscopy technique with the potential of reaching spatial resolutions well beyond the diffraction limits of x-ray microscopes based on optics. However, the available coherent dose at modern x-ray sources is limited, setting practical bounds on the spatial resolution of the technique. By focusing the available coherent flux onto the sample, the sp...

A generalized dynamical theory has been developed that extends previous models of x-ray diffraction from crystals and multilayers with vertical strains to the cases of grazing incidence and/or exit below the critical angle for total specular reflection. This provides a common description for extremely asymmetric diffraction, surface ~‘‘grazing-incidence’’!, and grazing Bragg-Laue diffraction, t...

A bone has a hierarchical structure as shown in Fig. 1 [1]. Macroscopic bone properties are dependent on the microstructure and properties of structural elements. The bone is a composite material that consists of hydroxyapatite particles in a matrix of collagen fiber. Borsato et al. [2] measured the strain of hydroxyapatite by X-ray diffraction and obtained clear evidence of the stress concentr...

X-ray Diffraction: A Practical Approach, C. Suryanarayana and M. Grant Norton, 1998. Plenum Press, New York and London. xiii + 273 pages. (hardback, $49.50, U.S. and Canada; $59.40, elsewhere).It is the aim of this text to teach undergraduates majoring in materials science the use of powder X-ray diffraction for materials characterization. Since it does not treat X-ray diffraction and crystallo...

Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to approximately 200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, an...

Fritillaria is a traditional Chinese herbal medicine for anti-tussive and expectorant use in China and some other Asian countries. The Fritillaria Chinese medicine material derived from different geographical origins is always difficult to discriminate each other. The objective of the study is to develop a nondestructive and simple method to identify five Fritillaria Chinese materia medica such...