scholarly journals The Albitization of K-Feldspar in Organic- and Silt-Rich Fine-Grained Rocks of the Lower Cambrian Qiongzhusi Formation in the Southwestern Upper Yangtze Region, China

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 620 ◽  
Author(s):  
Min ◽  
Zhang ◽  
Li ◽  
Zhao ◽  
Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lower Cambrian ◽  
Mineral Assemblage ◽  
Sedimentary Rocks ◽  
Pore Filling ◽  
X Ray ◽  
Fine Grained ◽  
Diagenetic Processes ◽  
Rock Structure ◽  
Scanning Electron

The albitization of K-feldspar is a common diagenetic process that has thus far received little attention and is not fully understood in fine-grained sedimentary rocks. To better understand the albitization of K-feldspar, studies in organic- and silt-rich fine-grained rocks of the lower Cambrian Qiongzhusi Formation in the southwestern Upper Yangtze region, China, were carried out via X-ray diffractometry (XRD) and field emission scanning electron microscopy (FE-SEM). The results show that five types of albitized K-feldspar textures have developed: microcrystal albite replacement, irregular blocky replacement along margins, cleavage planes or microcracks of K-feldspars, complete pseudomorphic replacement, albite overgrowth, and albite pore filling. Organic- and silt-rich fine-grained rocks differ from sandstones and mudstones in terms of the rock structure and mineral assemblage, which results in differences in the textures and degree of albitization of K-feldspar. Illitization of clay has an impact on the albitization of K-feldspar. In provenance analyses using feldspar, fine-grained rocks, especially those that underwent mesogenesis, should be treated with caution because detrital feldspars have been destroyed. Theoretically, the albitization of K-feldspar could increase the porosity of reservoirs, although, from our observations, most of the related secondary pores are cancelled out or became isolated pores due to other diagenetic processes (compaction, cementation, etc.) in organic- and silt-rich fine-grained rocks.

scholarly journals Crystal structure and Mössbauer effect in multiferroic 0.5BiFeO3-0.5Pb(Fe0.5Ta0.5)O3 solid solution

Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 177-181 ◽  
Author(s):  
Agata Stoch ◽  
Jan Maurin ◽  
Paweł Stoch ◽  
Jan Kulawik ◽  
Dorota Szwagierczak
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Solid Solution ◽  
Random Distribution ◽  
Magnetic Hyperfine Field ◽  
Small Contribution ◽  
X Ray ◽  
Fine Grained ◽  
Eds Analysis ◽  
Scanning Electron

Abstract Multiferroic 0.5BiFeO3-0.5Pb(Fe0.5Ta0.5)O3 solid solution is a material that exhibits ferroelectric and antiferromagnetic orderings in ambient temperature. The solid solution was obtained as a result of a conventional reaction in a solid state. The obtained material is a dense, fine-grained sinter whose surface was observed by scanning electron microscopy (SEM) and stoichiometry was confirmed by energy dispersive X-ray spectroscopic (EDS) analysis. According to the X-ray powder diffraction (XRD) measurements, the main phase is R3c space group with admixture of Pm-3m regular phase. Small contribution of pyrochlore-like phase was also observed. Mössbauer spectroscopy suggested random distribution of Fe3+/Ta5+ cations in the B sites of ABO3 compound. Reduction of the magnetic hyperfine field with an increase in the substitution of Ta5+ in Fe3+ neighbourhood was also observed.

Composition and Microstructures of Imperial Brass Chinese Coins

2010 ◽  
Vol 636-637 ◽  
pp. 531-537 ◽  
Author(s):  
M.J. Furtado ◽  
Rui Jorge C. Silva ◽  
M.F. Araújo ◽  
Francisco Manuel Braz Fernandes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Equilibrium Phase ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fine Grained ◽  
Minor Elements ◽  
Brass Alloys ◽  
Scanning Electron

Twenty brass Chinese cash coins with complex compositions were studied for a better understanding of the metallurgical cash production in China, during the 17th, 18th and 19th centuries. Elemental composition was obtained through energy-dispersive micro X-ray fluorescence spectrometry of small cleaned areas on the coins rims. Results showed that these brass alloys (Cu-Zn) frequently contain up to 3% Sn, have highly variable Pb content (from n.d. up to 14%) and Fe, Sb, and As as minor elements. Microstructures were assessed by optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and preliminary micro X-ray diffraction analysis. All the coins present typical as-cast microstructures although very fine-grained, which are supported by binary (Cu-Zn) and ternary (Cu-Zn-Sn) equilibrium phase diagrams, that explain microstructural differences due to the presence of Sn in these brasses.

Characteristics of halloysite associated with rectorite from Hubei, China

2006 ◽  
Vol 70 (3) ◽  
pp. 257-264 ◽  
Author(s):  
H.-L. Hong ◽  
J.-X. Mi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mineral Assemblage ◽  
Nanometer Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Mineralogical Characteristics ◽  
Water Saturated ◽  
Scanning Electron

AbstractThe mineralogical characteristics of halloysite in rectorite pelite in the Zhongxiang area, Hubei, China, were investigated using X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy methods. The results show that halloysite crystals exhibit euhedral lamellar, tubular or club-like, and needle-like or fibre-like morphologies, indicating that they crystallized from a significantly water-saturated environment. The mineral assemblage of the rectorite pelite is rectorite, halloysite, illite, gypsum, pyrite and rutile, suggesting a weak supergene alteration. Several features related to crystallization of halloysite were noted. Growth of halloysite on rectorite edge surfaces in voids and twins of halloysite on a nanometer scale with composition plane (110) were found in the Zhongxiang rectorite pelite, and, in particular, the tapered ends of tubes suggest that halloysite crystallized from solution. Disaggregation of lamellar halloysite particles into parallel clusters of single tubular halloysite crystals suggests that because of significant [H2O] activity in the environment, halloysite may have been derived from the alteration of rectorite.

Low Temperature Sintering of Ferro-Materials with Both Capacitance and Inductance Properties

2010 ◽  
Vol 434-435 ◽  
pp. 357-360
Author(s):  
Xi Wei Qi ◽  
Wei Qi Han ◽  
Pei Hua Wang-Yang ◽  
Hai Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Relaxor Ferroelectric ◽  
Electromagnetic Properties ◽  
Low Temperature Sintering ◽  
X Ray ◽  
Fine Grained ◽  
Nicuzn Ferrite ◽  
Scanning Electron

Ferro-materials which possess both capacitance and inductance were sintered at low temperature using Bi2O3 as sintering additives. The composition of ferro-materials is 0.4PMZNT- 0.6NiCuZn. PMZNT relaxor ferroelectric is a solid solution that consists of Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3Nb2/3)O3 and PbTiO3. NiCuZn ferrite with general formula is Ni0.2Cu0.2Zn0.6Fe2O4. Effects of the content of Bi2O3 and sintering temperature on the relative density of prepared ferro-materials have been studied. Dense ferro-materials were obtained at as low as 890°C with 2.0 wt% of Bi2O3. The X-ray diffractometer (XRD) identifications showed that ferro-materials consisted of distinct ferroelectric and ferromagnetic phases. Scanning electron microscopy (SEM) observations revealed that low temperature sintered ferro-materials possess high density and fine-grained microstructures. Prepared ferro-materials exhibit electromagnetic properties.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Use of SEM, X-ray analysis and TEM to localize Fe3+ reduction in roots

1988 ◽  
Vol 46 ◽  
pp. 392-393 ◽  
Author(s):  
William P. Wergin ◽  
P. F. Bell ◽  
Rufus L. Chaney
Keyword(s):  
Electron Microscopy ◽  
Root Hairs ◽  
Rapid Reduction ◽  
X Ray ◽  
Physical Evidence ◽  
Transmission Electron ◽  
Young Root ◽  
Insoluble Precipitate ◽  
Uptake And Transport ◽  
Scanning Electron

In dicotyledons, Fe3+ must be reduced to Fe2+ before uptake and transport of this essential macronutrient can occur. Ambler et al demonstrated that reduction along the root could be observed by the formation of a stain, Prussian blue (PB), Fe4 [Fe(CN)6]3 n H2O (where n = 14-16). This stain, which is an insoluble precipitate, forms at the reduction site when the nutrient solution contains Fe3+ and ferricyanide. In 1972, Chaney et al proposed a model which suggested that the Fe3+ reduction site occurred outside the cell membrane; however, no physical evidence to support the model was presented at that time. A more recent study using the PB stain indicates that rapid reduction of Fe3+ occurs in a region of the root containing young root hairs. Furthermore the most pronounced activity occurs in plants that are deficient in Fe. To more precisely localize the site of Fe3+ reduction, scanning electron microscopy (SEM), x-ray analysis, and transmission electron microscopy (TEM) were utilized to examine the distribution of the PB precipitate that was induced to form in roots.

Scanning Electron Microscopy and X-Ray Analyses of Dental Tissues from a Hibernator

1976 ◽  
Vol 34 ◽  
pp. 178-179
Author(s):  
M. L. Zimny ◽  
A. C. Haller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Temperature ◽  
Ground Squirrel ◽  
Alveolar Bone ◽  
X Ray ◽  
Dental Tissues ◽  
Bone Minerals ◽  
Apical Tooth ◽  
Scanning Electron

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

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