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A Hybrid Angular/Energy Dispersive Method to Improve Some Characteristics of Laboratory X-Ray Diffraction
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作者 V. Rossi Albertini D. Bailo +1 位作者 A. Generosi B. Paci 《Modern Instrumentation》 2012年第1期1-7,共7页
The Energy Dispersive X-ray Diffraction, generally referred as EDXD, has shown to be a valid alternative to the conventional Angular Dispersive X-ray Diffraction, the ADXD. EDXD exhibits several advantages to its AD c... The Energy Dispersive X-ray Diffraction, generally referred as EDXD, has shown to be a valid alternative to the conventional Angular Dispersive X-ray Diffraction, the ADXD. EDXD exhibits several advantages to its AD counterpart, mainly related to the properties of the polychromatic X-ray beam utilized for diffracting, such as higher signal intensities, a wider accessible region of the reciprocal space, a greater transparency of samples, and a parallel data collection of the q-points in the diffraction pattern acquisition. However, the main drawback of poly-chromaticity lays in the fact that the quantities that modulate the scattered intensity in a diffraction measurement depend on the energy. These quantities are the primary X-ray beam spectrum, polarization, and X-ray absorption, the last producing by far the most critical effect because it rapidly changes as a function of energy. Therefore, a detailed knowledge of the energy dependence of all these quantities is required in EDXD in order to process the data correctly and prevent systematic errors. The difficulty in handling the energy-dependent factors complicates the experimental procedure and may make the measurements unreliable. In the present paper, a hybrid method between the ED and AD X-ray Diffraction is proposed to maintain the advantages of the polychromatic nature of the radiation utilized in EDXD, while preventing the problems produced by the energy-dependent quantities. 展开更多
关键词 x-ray diffraction energy dispersIVE ANGULAR dispersIVE
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Energy-dispersive X-ray Spectroscopy for the Quantitative Analysis of Pyrite Thin Specimens
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作者 LUO Tingting GUO Yi +4 位作者 DENG Zhao LIU Xiaoqing SUN Zhenya QI Yanyuan YANG Meijun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第6期1304-1310,共7页
To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantit... To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides. 展开更多
关键词 analytical transmission electron microscopy(AEM) energy dispersive x-ray spectroscopy(EDS) PYRITE thin specimen quantitative analysis
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Phase Identification Using Series of Selected Area Diffraction Patterns and Energy Dispersive Spectrometry within TEM
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作者 Kun-Lin Lin 《Microscopy Research》 2014年第4期57-66,共10页
Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns... Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns (SADPs) are crystallographic data that can be obtained using a TEM in-strument. Conventional identification through SADP/TEM is tricky and tedious, thereby increasing the difficulty of phase identification. To establish a procedure for phase identification of known and unknown phases, in this study we examined two samples: one, a known phase, was Si with alignment;the other, unknown, was the TixOy phase at the 96.4Au-3Ni-0.6Ti interlayer/ yttria-stabilized zirconia (YSZ) interface of a steel/96.4Au-3Ni-0.6Ti interlayer/YSZ joint. The procedures for phase identification of the known and unknown phases are described herein using a series of SADPs and energy dispersive spectrometry within TEM that would be useful for general researchers. 展开更多
关键词 Phase Identification Transmission Electron MICROSCOPY SELECTED Area diffraction Pattern energy dispersIVE Spectroscopy
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Determination of Element Levels of Lagoon from Townships near Cocody City Abidjan Côte D’Ivoire Using Energy Dispersive X-Ray Fluorescence 被引量:1
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作者 Alfred Djoman Djama Agbo Koudou Djagouri +1 位作者 Jean-Claude Olkalé Brigui Konin Pierre-Claver Kakou 《World Journal of Nuclear Science and Technology》 2021年第2期109-118,共10页
Eight water bottles from Ebrie lagoon with pollution potency were studied using nuclear chemistry technique and Energy dispersive X-ray fluorescence. This pollution is characterized by pH and conductivity parameters, ... Eight water bottles from Ebrie lagoon with pollution potency were studied using nuclear chemistry technique and Energy dispersive X-ray fluorescence. This pollution is characterized by pH and conductivity parameters, concentrations average in mg/L of metals such Fe (0.731), Mn (0.345), Cr (0.070), Cu (0.014) and concentrations of nutrients known to be pollutants and toxic for living or-ganisms. These heavy metals are dangerous to the lives, the local inhabitants and also a threat to aquatic life since this water is essential for the economical town, Abidjan. According to the Manganese concentration average (0.345 mg) values that higher than WHO (0.05 mg) value, the main likely source of pollu-tants is anthropogenic, industrial and agricultural. This study also shows the use of materials and lubricants near the lagoon that pollute this water. 展开更多
关键词 Ebrie Lagoon POLLUTION Heavy Metals energy dispersive x-ray Fluorescence
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Ultrahard X-ray multifunctional application beamline at the SSRF
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作者 Ke Yang Zhao-Hui Dong +4 位作者 Chun-Yin Zhou Zi-Long Zhao Dong-Xu Liang Sai-Chao Cao Ai-Guo Li 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第6期14-25,共12页
The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray di... The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray diffraction and imaging using white and monochromatic light.The main scientific objectives of ultrahard X-ray beamlines are focused on two research areas.One is the study of the structural properties of Earth’s interior and new materials under extreme high-temperature and high-pressure conditions,and the other is the characterization of materials and processes in near-real service environments.The beamline utilizes a superconducting wiggler as the light source,with two diamond windows and SiC discs to filter out low-energy light(primarily below 30 keV)and a Cu filter assembly to control the thermal load entering the subsequent optical components.The beamline is equipped with dual monochromators.The first was a meridional bending Laue monochromator cooled by liquid nitrogen,achieving a full-energy coverage of 30-162 keV.The second was a sagittal bending Laue monochromator installed in an external building,providing a focused beam in the horizontal direction with an energy range of 60-120 keV.There were four experimental hutches:two large-volume press experimental hutches(LVP1 and LVP2)and two engineering material experimental hutches(ENG1 and ENG2).Each hutch was equipped with various near-real service conditions to satisfy different requirements.For example,LVP1 and LVP2 were equipped with a 200-ton DDIA press and a 2000-ton dual-mode(DDIA and Kawai)press,respectively.ENG1 and ENG2 provide in situ tensile,creep,and fatigue tests as well as high-temperature conditions.Since June 2023,the BL12SW has been in trial operation.It is expected to officially open to users by early 2024. 展开更多
关键词 Shanghai Synchrotron Radiation Facility Ultrahard x-ray High energy diffraction High energy imaging Engineering materials Earth science
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Alpha-actinin expression at different differentiating time points from temporal lobe cerebral cortex neural stem cells to neuron-like cells using energy dispersive X-ray analysis
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作者 Bo Yu Hua Li +3 位作者 Zhe Du Yang Hong Meng Sang Yuxiu Shi 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第4期265-270,共6页
BACKGROUND: Alpha-actinin ( a -actinin) plays a key role in neuronal growth cone migration during directional differentiation from neural stem cells (NSCs) to neurons. OBJECTIVE: To detect in situ microdistribut... BACKGROUND: Alpha-actinin ( a -actinin) plays a key role in neuronal growth cone migration during directional differentiation from neural stem cells (NSCs) to neurons. OBJECTIVE: To detect in situ microdistribution and quantitative expression of a -actinin during directional differentiation of NSCs to neurons in the temporal lobe cerebral cortex of neonatal rats. DESIGN, TIME AND SETTING: Between January 2006 and December 2008, culture and directional differentiation of NSCs were performed at Department of Histology and Embryology, Preclinical Medical College, China Medical University. Immune electron microscopy was performed at Department of Histology and Embryology and Department of Electron Micrology, Preclinical Medical College, China Medical University. Spectrum analysis was performed at Laboratory of Electron Microscopy, Mental Research Institute, Chinese Academy of Sciences. MATERIALS: Basic fibroblast growth factor, epidermal growth factor, brain-derived nerve growth factor, type-1 insulin like growth factor, and a -actinin antibody were provided by Gibco BRL, USA; rabbit-anti-rat nestin monoclonal antibody, rabbit-anti-rat neuron specific enolase polyclonal antibody, and EDAX-9100 energy dispersive X-ray analysis were provided by PHILIPS Company, Netherlands. METHODS: NSCs, following primary and passage culture, were differentiated with serum culture medium (DMEM/F12 + 10% fetal bovine serum + 2 ng/mL brain-derived nerve growth factor + 2 ng/mL type-1 insulin like growth factor). MAIN OUTCOME MEASURES: Expression of a -actinin in neuron-like cells was quantitatively and qualitatively detected with immunocytochemistry using energy dispersive X-ray analysis. RESULTS: Immunocytochemistry, combined with electron microscopy, indicated that positive α -actinin expression was like a spheroid particle with high electron density. In addition, the expression was gradually concentrated from the nuclear edge to the cytoplasm and expanded into developing neurites, during differentiation of neural stem cells to neurons. Conversely, energy dispersive X-ray analysis indicated that the more mature the neural differentiation was, and the greater the expression of α -actinin. CONCLUSION: The gradual increase of α -actinin expression is related to growth, development, and maturity of differentiated neuron-like cells, in neonatal rat frontal lobe cortex, at different differentiating time points of NSCs to neurons. 展开更多
关键词 energy dispersive x-ray analysis a -actinin neural stem cells directional differentiation NEURONS
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Energy Dispersive X-Ray Spectroscopy of the Sohnari Member of Laki Formation from Southern Indus Basin of Pakistan
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作者 Muhammad Asif Noonari Surih Sibaghatullah Jagirani +5 位作者 Huafeng Tang Asghar A. A. D. Hakro Ali Ghulam Sahito Kaleemullah Jagirani Shahid Ali Shaikh Muhammad Dodo Jagirani 《Open Journal of Geology》 2021年第6期183-196,共14页
This study determines the geochemical and depositional environment analysis of the sediments of the Sohnari Member of the Laki Formation, Northern Kirthar Fold Belt of Pakistan. The Energy-Dispersive-X-Ray Spectroscop... This study determines the geochemical and depositional environment analysis of the sediments of the Sohnari Member of the Laki Formation, Northern Kirthar Fold Belt of Pakistan. The Energy-Dispersive-X-Ray Spectroscopy (EDS) technique is used for the detection of major elements and the effects of shifting depositional climatic conditions of six representative samples which were acquired from the Sohnari Member of the Laki Formation at Lakhra area, Sindh, Pakistan. The sedimentological studies clarify that the sediments the Sonahri Member are relatively immature and most migrated in clastic mode. The availability of Silica shows that the Member was formed due to biochemical precipitation and detrital mode and was deposited at a fast rate of sediment deposition under the fluvio-deltaic depositional system. This is also deduced that the rapid rate of sediment deposition might be created a reducing atmosphere and allowing for the mineralization of sulphur. 展开更多
关键词 energy dispersive x-ray Spectroscopy GEOCHEMISTRY Sohnari Member the Laki Formation Northern Kirthar Fold Belt of Pakistan
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The Aqueous Dispersions of Bicontinuous Cubic Phases Formed by Precursor Method
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作者 JinZHANG DongHuaLI LiQiangZHENG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第6期823-826,共4页
The morphologies and the microstructures of the dispersed particles of the cubic phase, which were formed by precursor method, were studied. The freeze-fracture TEM clearly showed that the aqueous dispersed particles ... The morphologies and the microstructures of the dispersed particles of the cubic phase, which were formed by precursor method, were studied. The freeze-fracture TEM clearly showed that the aqueous dispersed particles have irregular cubic shapes. X-ray diffraction technique has been utilized to study the microstructure of the particles and it was found that these particles still retained the cubic character. The sizes of the particles were measured by dynamic light scattering, and the results showed that the sizes of the dispersed particles were between 200 ~ 400 nm under different conditions. 展开更多
关键词 FF-TEM x-ray diffraction dynamic light scattering aqueous dispersions precursor.
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Remarks on the Erroneous Dispersion Surfaces From a Pair of a Hyperbolic Branch and An Elliptical Arc of the Intersected Two Laue Spheres Based on the Usual Crude Approximation
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作者 Tetsuo Nakajima 《Journal of Modern Physics》 2011年第3期146-153,共8页
In almost all previous works, the hyperbolic dispersion surfaces of the central proper quadrics have been crudely derived from the degree of reduction from the bi-quadratic equation by use of some roughly indefinable ... In almost all previous works, the hyperbolic dispersion surfaces of the central proper quadrics have been crudely derived from the degree of reduction from the bi-quadratic equation by use of some roughly indefinable approximate relations. Moreover, neglecting the high symmetry of the hyperbola, both the branches have been approximated on the asymmetric surfaces composed of a pair of a branch of the hyperbola and a vertex of the ellipse without the presentation of reasonable evidence. Based upon the same dispersion surfaces equation, a new original gapless dispersion surfaces could be rigorously introduced without crude omission of even a term in the bi-quadratic equation based upon usual analogy with the extended band theory of solid as the close approximation to the truth. 展开更多
关键词 Dynamical Theory x-ray diffraction Gapless dispersion SURFACE Gappy dispersion Surface.
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Effect of wire-arc directed energy deposition on the microstructural formation and age-hardening response of the Mg-9Al-1Zn(AZ91)alloy
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作者 Gloria Graf Petra Spoerk-Erdely +4 位作者 Emad Maawad Michael Burtscher Daniel Kiener Helmut Clemens Thomas Klein 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期1944-1958,共15页
In recent years,wire-arc directed energy deposition(wa DED),which is also commonly known as wire-arc additive manufacturing(WAAM),has emerged as a promising new fabrication technique for magnesium alloys.The major rea... In recent years,wire-arc directed energy deposition(wa DED),which is also commonly known as wire-arc additive manufacturing(WAAM),has emerged as a promising new fabrication technique for magnesium alloys.The major reason for this is the possibility of producing parts with a complex geometry as well as a fine-grained microstructure.While the process has been shown to be applicable for Mg-Al-Zn alloys,there is still a lack of knowledge in terms of the influence of the WAAM process on the age-hardening response.Consequently,this study deals with the aging response of a WAAM AZ91 alloy.In order to fully understand the mechanisms during aging,first,the as-built condition was analyzed by means of high-energy X-ray diffraction(HEXRD)and scanning electron microscopy.These investigations revealed a finegrained,equiaxed microstructure with adjacent areas of alternating Al content.Subsequently,the difference between single-and double-step aging as well as conventional and direct aging was studied on the as-built WAAM AZ91 alloy for the first time.The aging response during the various heat treatments was monitored via in situ HEXRD experiments.Corroborating electron microscopy and hardness studies were conducted.The results showed that the application of a double-step aging heat treatment at 325℃with pre-aging at 250℃slightly improves the mechanical properties when compared to the single-step heat treatment at 325℃.However,the hardness decreases considerably after the pre-aging step.Thus,aging at lower temperatures is preferable within the investigated temperature range of 250-325℃.Moreover,no significant difference between the conventionally aged and directly aged samples was found.Lastly,the specimens showed enhanced precipitation kinetics during aging as compared to cast samples.This could be attributed to a higher amount of nucleation sites and the particular temperature profile of the solution heat treatment. 展开更多
关键词 Wire-arc directed energy deposition Additive manufacturing High-energy x-ray diffraction Synchrotron Mg-Al-Zn alloys AGE-HARDENING
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馆藏汉代瓦当表面可溶盐的化学组成分析
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作者 荆海燕 马芬 +2 位作者 郑丽珍 白璐 付文斌 《分析科学学报》 CAS CSCD 北大核心 2024年第2期244-248,共5页
采用离子色谱仪(IC),扫描电子显微镜-能谱仪(SEM-EDS),X射线衍射仪(XRD)和傅里叶变化显微红外光谱仪(FTIR)等现代分析仪器,对陕西历史博物馆馆藏的汉代瓦当表面可溶盐进行了鉴定,并分析了相关的化学组成。结果表明,瓦当表面可溶盐含有石... 采用离子色谱仪(IC),扫描电子显微镜-能谱仪(SEM-EDS),X射线衍射仪(XRD)和傅里叶变化显微红外光谱仪(FTIR)等现代分析仪器,对陕西历史博物馆馆藏的汉代瓦当表面可溶盐进行了鉴定,并分析了相关的化学组成。结果表明,瓦当表面可溶盐含有石膏(Ca SO_(4)·2H_(2)O)和有机酸钙盐[Ca_(3)(CH_(3)COO)_(3)Cl(NO_(3))_(2)·6H_(2)O]等成分。 展开更多
关键词 瓦当 可溶盐 扫描电子显微镜-能谱 X射线衍射 离子色谱
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Establishment of Energy Dispersive X-ray Diffraction Experimental System With Synchrotron Radiation Under High Pressure 被引量:2
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作者 车荣钲 周镭 +5 位作者 赵越超 顾惠成 王振杰 李凤英 王积方 陈良辰 《Chinese Science Bulletin》 SCIE EI CAS 1994年第22期1877-1881,共5页
Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase tra... Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase transition and 展开更多
关键词 high pressure SYNCHROTRON RADIATION x-ray diffraction energy dispersion.
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The development,performances and applications of the monochromatic X-rays facilities in(0.218–301)keV at NIM,China 被引量:4
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作者 Si-Ming Guo Jin-Jie Wu Dong-Jie Hou 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第6期108-121,共14页
Space scientific exploration is rapidly becoming the primary battlefield for humankind to explore the universe.Countries worldwide have launched numerous space exploration satellites.Accurate calibration of the detect... Space scientific exploration is rapidly becoming the primary battlefield for humankind to explore the universe.Countries worldwide have launched numerous space exploration satellites.Accurate calibration of the detectors on the ground is a crucial element for space science satellites to obtain observational results.For the purpose of providing calibration for various satellite-borne detectors,multiple monochromatic X-rays facilities have been built at the National Institute of Metrology,P.R.China(NIM).These facilities mainly pertain to grating diffraction and Bragg diffraction,and the energy range of the produced monochromatic X-rays is 0.218–301 ke V.These facilities have a high performance in terms of energy stability,monochromaticity,and flux stability.The monochromaticity was greater than 3.0%.The energy stability of the facility is 0.02%at 25 ke V over 8 h,and the flux stability was within 1.0%at 25 ke V over 8 h.Calibration experiments on the properties of satellite-borne detectors,such as energy linearity,energy resolution,detection efficiency,and temperature response,can be conducted at the facilities.Thus far,the calibration of two satellites has been completed by the authors,and the work on three other satellites is in progress.This study will contribute to the advancement of X-ray astronomy the development of Chinese space science. 展开更多
关键词 Monochromatic x-rays MONOCHROMATOR Bragg diffraction energy spectra Calibration
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Goss Texture Evolution of Grain Oriented Silicon Steel by High-Energy X-ray Diffraction 被引量:4
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作者 Yong Liu Qiwu Jiang +3 位作者 Yong Wang Yang Ren A.Tidu Liang Zuo 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2014年第3期530-533,共4页
High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture ({ [10}(001)) of grain oriented (GO) silicon steel... High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture ({ [10}(001)) of grain oriented (GO) silicon steel during secondary recrystallization process, an in situ experiment using hi gh energy X-ray diffraction was designed. The results showed that the secondary recrystallization began when the heating temperature was 1,494 K, and the grains grew rapidly above this temperature. With an increase in annealing temperature, the large grains with 7 orientation [〈111〉//normal direction] formed and gradually occupied the dominant position. As the annealing temperature increased even further, the grains with Goss orientation to a very large size by devouring the 7 orientation grains that formed in the early annealing stage. A single crystal with a Goss orientation was observed in the GO silicon steel when the annealing temperature was 1,540 K. 展开更多
关键词 Grain oriented silicon steel TEXTURE Secondary recrystallization High energy x-ray diffraction (HEXRD)
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Production and Characterization of Nano Structured Silicon Carbide by High Energy Ball Milling
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作者 J. Babu Rao Dil Kush NRMR Bhargava 《Journal of Minerals and Materials Characterization and Engineering》 2012年第5期529-541,共13页
The article has been retracted due to the investigation of complaints received against it. The Editorial Board found that substantial portions of the text came from other published paper. Comparing with the paper publ... The article has been retracted due to the investigation of complaints received against it. The Editorial Board found that substantial portions of the text came from other published paper. Comparing with the paper published in International Journal of Engineering, Science and Technology Vol. 3, No. 4, 2011, pp. 82-88 (www.ijest-ng.com), these two papers have the same contents before Figure 7 and the author added Fig. 8, 9, 10 on the 2012 paper. The scientific community takes a very strong view on this matter, and the Journal of Minerals and Materials Characterization and Engineering (JMMCE) treats all unethical behavior seriously. This paper published in Vol.11 No.5, 529-541, 2012 has been removed from this site. 展开更多
关键词 Nano PARTICLES Silicon CARBIDE High energy BALL MILLING x-ray diffraction SEM.
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X-Ray and Mössbauer Study of Magnetic Black Sand from Mayotte Island
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作者 Saverio Braccini Karl Krämer Stephane Chapenoire 《World Journal of Nuclear Science and Technology》 2016年第4期191-198,共9页
Natural magnetic black sands are known from several sites often located in areas of volcanic origin. Their elemental and mineral composition provides information on the geology of their territory and depends on severa... Natural magnetic black sands are known from several sites often located in areas of volcanic origin. Their elemental and mineral composition provides information on the geology of their territory and depends on several factors occurred during their formation. A sample of black sand was collected on the seashore of the island of Mayotte in the Indian Ocean and its magnetic part was investigated by means of energy dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD), and M&#214;ssbauer spectroscopy at room temperature. The mineral composition is dominantly magnetite, in good agreement with samples collected in other sites of volcanic origin. Contrary to pure magnetite, a relevant fraction of Ti was detected by EDS. The 16% Ti and 1% Mn content increase the magnetite lattice parameter to 8.4312 (25) &#197;. The broadening of XRD lines pointed towards a significant degree of disorder. This was confirmed by M&#214;ssbauer spectroscopy and is attributed to the presence of Ti replacing Fe in the magnetite lattice. The presence of Ti modifies the local magnetic field on the Fe sites, leading to a broader and more complex M&#214;ssbauer transmission spectrum with respect to the one of pure magnetite. To study the effect of temperature, samples were heated for 12 hours to 600&deg;C and 800&deg;C in argon and to 1000&deg;C in air. Annealing in argon did not improve the crystallinity while annealing in air caused a complete decomposition of magnetite into hematite and pseudobrookite. 展开更多
关键词 Magnetic Black Sand Iron Minerals energy dispersive x-ray Spectroscopy x-ray diffraction Mössbauer Spectroscopy
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Mossbauer,X-Ray and Magnetic Studies of Black Sand from the Italian Mediterranean Sea
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作者 Saverio Braccini Olivier Pellegrinelli Karl Kramer 《World Journal of Nuclear Science and Technology》 2013年第3期91-95,共5页
The study of natural magnetic sands is instrumental to investigate the geological aspects of their formation and of the origin of their territory. In particular, Mossbauer spectroscopy provides unique information on t... The study of natural magnetic sands is instrumental to investigate the geological aspects of their formation and of the origin of their territory. In particular, Mossbauer spectroscopy provides unique information on their iron content and on the oxidation state of iron in their mineral composition. The Italian coast on the Mediterranean Sea near Rome is known for the presence of highly magnetic black sands of volcanic origin. A study of the room temperature Mossbauer spectrum, powder X-ray diffraction, energy dispersive X-ray spectroscopy, and magnetic measurements of a sample of black magnetic sand collected on the seashore of the town of Ladispoli is performed. This study reveals magnetite as main constituent with iron in both tetrahedral and octahedral sites. Minor constituents are the iron minerals hematite and ilmenite, the iron containing minerals diopsite, gossular, and allanite, as well as ubiquitous sanidine, quartz, and calcite. 展开更多
关键词 Mossbauer Spectroscopy x-ray diffraction (XRD) energy dispersive x-ray Spectroscopy (EDS) Magnetic Sands Iron Minerals
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Possible Relevance of the Allende Meteorite Conditions in Prebiotic Chemistry: An Insight into the Chondrules and Organic Compounds
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作者 Alejandro Heredia Barbero Héctor G. Vázquez López +8 位作者 Adriana L. Meléndez López Jorge A. Cruz Castañeda Daniel Luna Laviada Karina E. Cervantes de la Cruz Victor Meza Laguna Vladimir A. Basiuk Ivonne Rosales Chávez Alicia Negrón Mendoza Sergio Ramos Bernal 《Advances in Biological Chemistry》 2023年第3期82-99,共18页
The study of the mineral and organic content of the Allende meteorite is important for our understanding of the molecular evolution of the universe as well as the ancient Earth. Previous studies have characterized the... The study of the mineral and organic content of the Allende meteorite is important for our understanding of the molecular evolution of the universe as well as the ancient Earth. Previous studies have characterized the magnetic minerals present in ordinary and carbonaceous chondrites, providing information on the evolution of magnetic fields. The interaction of organic compounds with magnetic minerals is a possible source of chemical diversity, which is crucial for molecular evolution. Carbon compounds in meteorites are of great scientific interest for a variety of reasons, such as their relevance to the origins of chirality in living organisms. This study presents the characterization of organic and mineral compounds in the Allende meteorite. The structural and physicochemical characterization of the Allende meteorite was accomplished through light microscopy, powder X-ray diffraction with complementary Rietveld refinement, Raman and infrared spectroscopy, mass spectrometry, scanning electron microscopy, and atomic force microscopy using magnetic signal methods to determine the complex structure and the interaction of organic compounds with magnetic Ni-Fe minerals. The presence of Liesegang-like patterns of chondrules in fragments of the Allende structure may also be relevant to understanding how the meteorite was formed. Other observations include the presence of magnetic materials and nanorod-like solids with relatively similar sizes as well as the heterogeneous distribution of carbon in chondrules. Signals observed in the Raman and infrared spectra resemble organic compounds such as carbon nanotubes and peptide-like molecules that have been previously reported in other meteorites, making the Mexican Allende meteorite a feasible sample for the study of the early Earth and exoplanetary bodies. 展开更多
关键词 Allende Meteorite Carbonaceous Chondrite Light Microscopy x-ray diffraction with the Rietveld Method Raman Spectroscopy Attenuated Total Reflectance Infrared Spectroscopy Mass Spectrometry Scanning Electron Mi-croscopy energy dispersive x-ray Spectroscopy Magnetic Force Microscopy
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广西桂西地区沉积型铝土矿矿物特征研究
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作者 韦连军 陈燕清 +1 位作者 雷满奇 黄庆柒 《岩矿测试》 CAS CSCD 北大核心 2023年第6期1220-1229,共10页
随着中国铝土矿资源日益消耗,高硫铝土矿将成为重要的新型铝土矿资源。中国有大量品位较高的高硫型沉积型铝土矿,但这类矿石由于硫含量高(硫含量>0.7%),严重影响后续提铝工艺流程,因而一直未被工业化利用,在铝土矿资源日益紧缺之时,... 随着中国铝土矿资源日益消耗,高硫铝土矿将成为重要的新型铝土矿资源。中国有大量品位较高的高硫型沉积型铝土矿,但这类矿石由于硫含量高(硫含量>0.7%),严重影响后续提铝工艺流程,因而一直未被工业化利用,在铝土矿资源日益紧缺之时,若能开发利用,对中国铝工业发展具有重要意义。2020—2021年在广西桂西地区自平果—靖西一带铝土矿成矿带新探获得相当量的沉积型铝土矿,该沉积型铝土矿是堆积型铝土矿的矿源层,二者在空间分布上存在重叠,矿石多与黄铁矿密切共生,部分矿段的硫含量高出工业利用允许最高含量的数倍或数十倍,尽管矿石品位较高,但硫含量多在2%~8%,目前该铝土矿矿石性质及工业化技术指标尚不明确。因此,本文以广西桂西地区的沉积型铝土矿为研究对象,采用X射线荧光光谱、偏光显微镜、X射线衍射及扫描电镜-能谱等分析测试技术研究了铝土矿的矿石矿物组成特性,探究了沉积型铝土矿的矿石性质。分析结果表明,该矿石中Al2O3含量为64.21%,S含量为5.13%,属于高硫沉积型铝土矿;矿石中铝矿物主要为一水硬铝石、绿泥石;铁矿物主要有黄铁矿、赤铁矿及褐铁矿;一水硬铝石,其结晶粒度细,呈鲕状集合体形式,表面较光滑;黄铁矿中粗粒、中粒级黄铁矿多以半自形及他形存在,粒径较大。结合本项目组早前对高硫型铝土矿进行的大量试验研究认为,该沉积型铝土矿高硫问题可通过选矿技术方法分离黄铁矿,后续建议通过破碎磨矿手段使矿石矿物单体解离,再辅以合理的选矿药剂制度将黄铁矿浮选分离出来,从而使浮硫后的含铝矿物满足下一步的氧化铝提取入料要求。 展开更多
关键词 沉积型铝土矿 矿物特征 黄铁矿 X射线荧光光谱法 X射线衍射法 扫描电镜-能谱法
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煅烧煤系高岭石的相转变 被引量:51
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作者 魏存弟 马鸿文 +2 位作者 杨殿范 李益 三国彰 《硅酸盐学报》 EI CAS CSCD 北大核心 2005年第1期77-81,共5页
通过X射线衍射分析,红外光谱分析,魔角旋转核磁共振和能量色散等测试手段,研究了煤系高岭石在200~1300℃下煅烧的相转变过程。结果表明:煅烧高岭石的相转变经历了4个阶段:脱羟阶段(≈550℃),偏高岭石阶段(550~850℃),SiO2分凝(850~1... 通过X射线衍射分析,红外光谱分析,魔角旋转核磁共振和能量色散等测试手段,研究了煤系高岭石在200~1300℃下煅烧的相转变过程。结果表明:煅烧高岭石的相转变经历了4个阶段:脱羟阶段(≈550℃),偏高岭石阶段(550~850℃),SiO2分凝(850~1100℃)及Al2O3分凝阶段(950~1100℃),莫来石阶段(>1100℃)。550℃时高岭石失去羟基水,转变为半晶态的偏高岭石。偏高岭石莫来石的相转变过程中存在SiO2和Al2O3的分凝。能量色散分析证实了分凝Al2O3的存在。950℃的新生相是γAl2O3而不是AlSi尖晶石。莫来石是由偏高岭石分凝形成的SiO2和Al2O3反应而形成的。 展开更多
关键词 高岭石 相转变 偏高岭石 莫来石 魔角旋转核磁共振
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