نتایج جستجو برای: quartz crystals
تعداد نتایج: 67066 فیلتر نتایج به سال:
In moulding of large-size castings, the lack of uniformity in heating results in the deformation of individual mould parts. The resulting deformations cause internal stre-sses in the casting and scabbing in the mould. The main cause of deformation in the mould element is to be found in the α β transformation of the quartz grains. The allotropic modification of the quartz crystals from α into β ...
BACKGROUND Inhalation of crystalline silica induces a pulmonary fibrotic degeneration called silicosis caused by the inability of alveolar macrophages to dissolve the crystalline structure of phagocytosed quartz particles. Ascorbic acid is capable of partially dissolving quartz crystals, leading to an increase of soluble silica concentration and to the generation of new radical sites on the qua...
The Noghduz prospecting area, as a part of the Arasbaran metallogenic zone is located about 20 km east of Ahar, East-Azarbaijan Province. The mineralization host rocks are andesite-trachy andesite with the age of Late Eocene. The hydrothermal alterations exposed in this area are silicic, argillic, and propylitic. Pyrite is the main hypogene sulfide mineral which is accompanied by lesser amou...
We demonstrate the combined use of liquid and air measurements with the quartz crystal microbalance (QCM) for quantitative analysis of multistep reaction procedures leading to immobilized proteins on solid surfaces. Reactions are conducted on the surfaces of QCM sensor crystals and are quantified by measurements of resonant frequency of the crystals before and after each reaction step. When rea...
As widespread, continuous instrumental Earth surface air temperature records are available only for the last hundred fifty years, indirect reconstructions of past temperatures are obtained by analyzing "proxies". Fluid inclusions (FIs) present in virtually all rock minerals including exogenous rocks are routinely used to constrain formation temperature of crystals. The method relies on the pres...
We bring together tables of current defect nomenclature and a summary of the rules actually practised (rather than idealised schemes) in choosing such labels for signals obtained with a range of spectroscopies. As well as providing a source of reference for the user lost in a maze of labels, the compilation also indicates parallels between similar defect species in very different systems (e.g. ...
Sinter overlying the first quartz andesite flow at base of Serra Geral Group is a surface manifestation intense hydrothermal processes operating in Paraná Basin during Early Cretaceous. The coarse sinter from western Rio Grande do Sul state was studied satellite images, field surveying, optical petrography, scanning electron microscopy, and probe microanalyses, including backscattered images ch...
Native lead, a rare mineral, occurs in a late-stage vein in the world’s largest lead – zinc – silver deposit, at Broken Hill, Australia. The lead-bearing vein consists mainly of laumontite, quartz, biotite and muscovite, together with minor amounts of lead, galena, sphalerite, molybdenite, and rare allanite-(Ce). Three types of fluid inclusions have been identified: two-phase brine inclusions l...
In the glass industry, nucleation agents are broadly used to obtain homogeneously dispersed and nanograined crystals during heat treatment leading to glass ceramics. In this paper, the role of zirconia and titania used as nucleation agents in a lithium alumosilicate glass is studied on the nanoscale using cutting edge analytical and imaging techniques performed in the transmission electronmicro...
We report p-type tin monoselenide (SnSe) single crystals, grown in double-sealed quartz ampoules using a modified Bridgman technique at 920 °C. X-ray powder diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) measurements clearly confirm that the grown SnSe consists of single-crystal SnSe. Electrical transport of multi-layer SnSe nanoflakes, which were prepared by exfoliation from ...
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