We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction anal...We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction analysis.On the basis of sedimentary characteristics we have summarized the petrological and mineralogical characteristics of the salt lake and proposed 9 types of grade IV salt rhythms.The deposition shows a desalting to salting order of halite-argillaceous-mudstone-mud dolostonemud anhydrock-glauberite-halite.The relationship among grade IV rhythms,water salinity and climate fluctuations was analyzed.Based on the analysis of the relationship between boron content and mudstone color and by combining the mineralogy and sedimentary environment characteristics,we propose that the early and late Paleocene Shashi Formation in the Jiangling Depression was a paleolacustrine depositional environment with a high salt content,which is a representation of the shallow water salt lake depositional model.The middle Paleocene Shashi Formation and the early Eocene Xingouzui Formation were salt and brackish sedimentary environments with low salt content in a deep paleolake,which represents a deep salt lake depositional model.展开更多
The process of mechanically assisted hydriding and subsequent thermal dehydriding was proposed to produce nanocrystalline Mg and Mg alloy powders using pure Mg and Mg-5.5%Zn-0.6%Zr(mass fraction)(ZK60 Mg) alloy as the...The process of mechanically assisted hydriding and subsequent thermal dehydriding was proposed to produce nanocrystalline Mg and Mg alloy powders using pure Mg and Mg-5.5%Zn-0.6%Zr(mass fraction)(ZK60 Mg) alloy as the starting materal.The hydriding was achieved by room-temperature reaction milling in hydrogen.The dehydriding was carried out by vacuum annealing of the as-milled powders.The microstructure and morphology of both the as-milled and subsequently dehydrided powders were characterized by X-ray diffraction analysis(XRD) ,transmission electron microscopy(TEM) ,and scanning electron microscopy(SEM) ,respectively.The results show that,by reaction milling in hydrogen,both Mg and ZK60 Mg alloy can be fully hydrided to form nanocrystalline MgH2 with an average grain size of 10 nm.After subsequent thermal dehydriding at 300℃,the MgH2 can be turned into Mg again,and the newly formed Mg grains are nanocrystallines,with an average grain size of 25 nm.展开更多
By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction met...By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction method. In order to determine the operating conditions of the system, the effects of the concentration of Fe3+ ions(ranging from 0.1 to 0.2 mol/L), the liquid-gas volume ratio(ranging from 15 to 25 L/m3) and the high gravity factor(ranging from 36 to 126) on the removal of H2 S were studied by means of the Box-Behnken design(BBD) under response surface methodology(RSM). The overall results have demonstrated that the BBD with an experimental design can be used effectively in the optimization of the desulfurization process. The optimal conditions based on both individualized and combined responses(at a Fe3+ ion concentration of 0.16 mol/L, a liquid-gas volume ratio of 20.67 L/m3 and a high gravity factor of 87) were found. Under this optimum condition, the desulfurization efficiency could reach 98.81% when the H2 S concentration was 7 g/m3 in APG. In this work, the sulfur product was analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and the energy dispersive X-ray spectrometer(EDX). The results of analysis show that the sulfur is made of the high-purity orthorhombic crystals, which are advantageous to environmental conservation.展开更多
Au/γ-Al2O3 catalysts were prepared by deposition-precipitation method for the catalytic combustion of low concentration alcohol streams(methanol,ethanol,iso-propanol and n-propanol).The catalysts were characterized b...Au/γ-Al2O3 catalysts were prepared by deposition-precipitation method for the catalytic combustion of low concentration alcohol streams(methanol,ethanol,iso-propanol and n-propanol).The catalysts were characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffractometry(XRD) and energy dispersive X-ray micro analysis(EDS) techniques.The XPS results showed that there was only Au0 on the surface of catalysts.The XRD patterns showed that Au was presumably highly dispersed over γ-Al2O3.The temperatures for complete conversion of methanol,ethanol,iso-propanol and n-propanol with concentration of 2.0 g/m3 were 60,155,170 and 137 ℃,respectively,but they were completely mineralized into CO2 and H2O at 60,220,260 and 217 ℃ respectively over the optimized catalyst.The activity of the catalyst was stable in 130 h.The kinetics for the catalytic methanol elimination followed quasi-first order reaction expressed as r=0.652 8c0+0.084 2.The value of apparent activation energy is 54.7 kJ/mol in the range of reaction temperature.展开更多
Al-Si/15%SiCp(volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy(OM). Dry slid...Al-Si/15%SiCp(volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy(OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10-220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy(SEM) and energy-dispersive X-ray microanalysis(EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiCp composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiCp and Al-13Si/15%SiCp composites, while Al-20Si/15%SiCp presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.展开更多
In order to characterize various micromorphologic properties of two forest soils derived from different parent rocks in Lahijan, and use the data collected from micromorphological analysis to interpret dominant pedoge...In order to characterize various micromorphologic properties of two forest soils derived from different parent rocks in Lahijan, and use the data collected from micromorphological analysis to interpret dominant pedogenic processes. Two representative soil pedons, granite (P1) and andesitic basalt (P2) were selected in a mountain landform with northwest aspect. Samples for thin section preparation were taken from each horizon by Kubiena boxes or clods. Micromorphological analysis of soils derived from these two soil pedons in eastern part of Lahijan (northern Iran) were conducted based on the physicochemical and mineralogical data. Micromorphological properties were characterized using a polarized light microscope under plain and cross light. Thin section study indicated that the nature of the parent material clearly affected the content of clay formation. It also showed that clay accumulation in the Bt horizons was not only due to clay illuviation (argillan), but that strong in situ weathering of primary minerals also contributed to the enrichment of clay in soils derived from andesitic basalt. Comparing the results of clay mineralogy obtained from X-ray diffraction (XRD) with microscopic studies revealed that birefringence fabric (b-fabric) of the groundmass was partly striated due to smectitic minerals in soil of andesitic basalt (Hapludalf), whereas speckled birefringence fabric was dominant in soil of granite (Udorthent) because of the absence of these minerals. We speculate that pores of skeletal fragments or microcracks in P1 were a place for illuvial clay protection. However, the main factor for flluvial clay film disruption (striation anddeformation) was biological activity (faunal turbation and root pressure) in P1 and expandable minerals and faunal turbation in P2.展开更多
An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The coating layer is composed of AI phas...An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The coating layer is composed of AI phase and exhibits superior corrosion resistance. The formation of the coating is mainly attributed to the obstruction of expansion of the transition zone by primarily solidified Mg]7All2 during rapid cooling, and the diffusion is restricted in a thin layer. These results show that droplet spraying is a promising way to protect magnesium by using corrosion-resistant materials available now.展开更多
ZnO-Bi2O3-based varistor ceramics doped with EU2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900-1000 ℃ for 2 h. XRD and SEM were applied to determine the phases and microstruct...ZnO-Bi2O3-based varistor ceramics doped with EU2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900-1000 ℃ for 2 h. XRD and SEM were applied to determine the phases and microstructure of the varistor ceramics. A DC parameter instrument was applied to investigate the electronic properties and V-I characteristics. The XRD analysis of Eu2O3-doped ZnO-Bi2O3-based varistor ceramics shows that the ZnO, Eu-containing Bi-rich, Zn7Sb2O12-type spinel and Zn2Bi3Sb3O14-type which is the pyrochlore phase are present. With increasing Eu2O3 content, the average size of ZnO grain firstly decreases and then increases. The grain boundary defect model was particularly used to explain the excellent nonlinearity of ZnO-Bi2O3-based varistor ceramics with the addition of0.1% Eu2O3 and sintered at 950 ℃.展开更多
The effect of precipitation on the internal friction(IF)of AZ91 magnesium alloy was investigated by using X-ray diffraction(XRD)analysis,scanning electron microscope(SEM)observation,and dynamic mechanical analysis(DMA...The effect of precipitation on the internal friction(IF)of AZ91 magnesium alloy was investigated by using X-ray diffraction(XRD)analysis,scanning electron microscope(SEM)observation,and dynamic mechanical analysis(DMA).Six different states of alloy were prepared by applying different heat treatment processes:as-cast,in-complete solid solution,complete solid solution,micro-precipitation,continuous precipitation and continuous-discontinuous precipitation.It was found that the internal friction of in-completely solid-solutionized,completely solid-solutionized and micro-precipitated specimens showed a similar characteristic,and the grain boundary relaxation is completed depressed due to the Al atoms supersaturated in theα-Mg solution.However,a thermal relaxation internal friction peak was observed for continuously precipitated and continuously-discontinuously precipitated specimens at around 438 K and frequency of about 1 Hz,which was attributed to the grain boundaries relaxation.Furthermore,it was found that the relaxation of theβ-Mg17Al12/α-Mg phase interfaces should give its contribution to the background internal friction in the as-cast,continuously precipitated and continuously-discontinuously precipitated specimens.展开更多
The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of tem- perature on mudstone ...The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of tem- perature on mudstone composition and fracture mechanism were studied from a meso-structural per- spective, and the relationship between meso-structure and macro-mechanical characteristics at high temperature was revealed. The findings demonstrated that the fluctuation in diffraction intensity of kao- linite in the mudstone caused the fluctuation in its mechanical properties. The overall structure under- went a phase change around 600℃, which led to the sudden change in the mechanical properties of mudstone samples. When the temperature reached 600 ℃, the crystalline state worsened and kaolinite disappeared; however, some illite was produced, indicating that the chemical reaction of the structure and sudden drop of bearing capacity of the mudstone. Mudst0ne fracturing at high temperature involves mainly intergranular and transgranular fractures, which are typical in micro-brittle tensile failure. Con- sidering the macro-fracture characteristics of mudstone, the results suggested that macro-fracture under external force corresoonds to the meso-fracture.展开更多
In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples f...In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope(SEM)and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions.展开更多
Based on the techniques of X-ray diffraction analysis, identification of the thin sections of core cast, phys- ical analysis and scanning electron microscopy analysis, this paper studied the reservoir characteristics ...Based on the techniques of X-ray diffraction analysis, identification of the thin sections of core cast, phys- ical analysis and scanning electron microscopy analysis, this paper studied the reservoir characteristics of the Carboniferous strata in Donghe well No.1 of Tarim region. The results show that the reservoir lithology is mainly the fine-grained quartz sandstone with ferrocalcite and pyrite, mud cement-based, the permeability concentrated in 5-40 × 10-3 μm2, a small part of the high permeability up to 150-327 ×10-3 μm2 and porosity ranged from 10% to 20%. The most part of the reservoirs is low perme- ability with a small part of the layer in moderate-high permeability. The types of reservoir space include intergranular pores, intra particle-molding pores, micro-pores and cracks, which mainly are intergranular pores with the pore diameter of 15-200 μm, 95.5μm on average. And the types of the throats are comolex with the main tvne of constricted l:hroats in this area and large contribution to the permeability.展开更多
FeCrAI (Ce) stainless steel was functionalized by a conversion treatment in order to allow alumina by diffusion coatings with strong interfacial bonding. The very porous conversion coating produced in a pack alumini...FeCrAI (Ce) stainless steel was functionalized by a conversion treatment in order to allow alumina by diffusion coatings with strong interfacial bonding. The very porous conversion coating produced in a pack aluminization technique had excellent adhesion and was conductive enough to permit conditions favorable for the precipitation of alumina oxyhydroxide during aluminum diffusion coatings. In this work, the bed was prepared as a mixture of A1, NH4C1 and A1203. In the high-activity bed were heat-treated at 1,173 K in an atmosphere made up of team with subsequent air-cooling. The effect of the bed content on the coating was examined. With the high-activity, the desired Fe2Al5 was formed as the outermost coating layer. The coating presented chemical composition gradients suitable for strong adhesion. The improvement of the thermal oxidation behaviour was studied at 1,373 K. Two different aqueous environments, which are (1) NaC1 and (2) H2SO4, are employed for using the technique of potentiodynamic polarization curve. The obtained experimental electrochemical parameters (Ecorr, Jcorr etc,) were used to compare the corrosion resistance of the tested steel state complemented by MEB (electronic scanning microscopy) in combination with dispersive analysis X in energy (EDS) or X ray diffraction indicated that the elements concentration maximum was located in the vicinity of the interface especially in the FeCrAI (Ce) coated by spherical A1203 powder. These results an discussed in terms of an addition effect on the development of the microstructure of oxide films.展开更多
This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Ger...This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Gerais State in Brazil. Two soapstone blocks were placed outdoors under tropical environmental conditions for 12 months. A total of 9 filamentous fungal populations were identified on their surfaces, namely Acremomium (cf.) alternatum, Alternaria alternata, Aspergillusfumigatus, Calcarisporium (cf.) arbuscula, Cladosporium cladosporioides, Curvularia lunata, Epicoccum nigrum, Fusarium equiseti and Penicillium citrinum. The gamma radiation assay was then carried out as a test of biocidal action by exposing all fungal populations to the ionizing radiation. The results showed that only the C. cladosporioides species was resistant to this biocidal agent, since it was able to increase its population post exposure. Scanning electron microscopy images identified the microbial colonization on the soapstone blocks and the stone elementar composition was analyzed by energy dispersive X-ray spectrometry. After treatment, there was no structural and aesthetic alteration in the soapstone samples, and evidencing that gamma radiation can be used as a biocidal agent. However, the resistance of the black fungal population indicates caution in the choice of gamma irradiation as biocidal treatment.展开更多
A ceramic superconductor compound with composition YBa2(C u3)1-xA gxO6.5x+δhas been prepared experimentally by solid state reaction from principal roots of high purity materials like Y203, BaO, CuO and Ag20. The s...A ceramic superconductor compound with composition YBa2(C u3)1-xA gxO6.5x+δhas been prepared experimentally by solid state reaction from principal roots of high purity materials like Y203, BaO, CuO and Ag20. The study was concentrated on the effect of partial substitution of Ag with respect to Cu atoms by the ratios (x = 0, 1, 0.2, 0.3, 0.4 and 0.5) through different analysis and measurements. X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Resistivity measurement is play an important role to show the improvement on high superconducting phase. It was found that the best substituted value of (x = 0.5) investigated a favor value of Tc equal nearly to (123 K), due to more excess of Ag atoms in the structure. X-ray diffraction showed an orthorhombic structure related to high-To phase with high stability through diminishing some peaks related to low temperature superconducting phase, that was related to presence of multiphase derivative from YBCO-phase. SEM pictures give us more details on the surface morphology, grain and grain boundaries, it gives an indication on successful of sintering process, the last one is very important in forming superconducting phase.展开更多
基金Supported by the National Basic Research Program of China(973 Program)(No.20011CB403007)the National Natural Science Foundation for Young Scientists of China(Nos.41502089,41202059)+1 种基金the Central Public Welfare Scientific Research Basic Scientific Research Business Expenses(No.K1415)the Geological Survey(No.1212010011808)
文摘We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction analysis.On the basis of sedimentary characteristics we have summarized the petrological and mineralogical characteristics of the salt lake and proposed 9 types of grade IV salt rhythms.The deposition shows a desalting to salting order of halite-argillaceous-mudstone-mud dolostonemud anhydrock-glauberite-halite.The relationship among grade IV rhythms,water salinity and climate fluctuations was analyzed.Based on the analysis of the relationship between boron content and mudstone color and by combining the mineralogy and sedimentary environment characteristics,we propose that the early and late Paleocene Shashi Formation in the Jiangling Depression was a paleolacustrine depositional environment with a high salt content,which is a representation of the shallow water salt lake depositional model.The middle Paleocene Shashi Formation and the early Eocene Xingouzui Formation were salt and brackish sedimentary environments with low salt content in a deep paleolake,which represents a deep salt lake depositional model.
基金Project(50574034)supported by the National Natural Science Foundation of ChinaProject(20060213016)supported by Doctoral Education Fund of Ministry of Education of China
文摘The process of mechanically assisted hydriding and subsequent thermal dehydriding was proposed to produce nanocrystalline Mg and Mg alloy powders using pure Mg and Mg-5.5%Zn-0.6%Zr(mass fraction)(ZK60 Mg) alloy as the starting materal.The hydriding was achieved by room-temperature reaction milling in hydrogen.The dehydriding was carried out by vacuum annealing of the as-milled powders.The microstructure and morphology of both the as-milled and subsequently dehydrided powders were characterized by X-ray diffraction analysis(XRD) ,transmission electron microscopy(TEM) ,and scanning electron microscopy(SEM) ,respectively.The results show that,by reaction milling in hydrogen,both Mg and ZK60 Mg alloy can be fully hydrided to form nanocrystalline MgH2 with an average grain size of 10 nm.After subsequent thermal dehydriding at 300℃,the MgH2 can be turned into Mg again,and the newly formed Mg grains are nanocrystallines,with an average grain size of 25 nm.
基金financially supported by the National Science Foundation of China (No. 21376229)the Science and Technology Development Plan of Shanxi Province (No. 20130321035-02)
文摘By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction method. In order to determine the operating conditions of the system, the effects of the concentration of Fe3+ ions(ranging from 0.1 to 0.2 mol/L), the liquid-gas volume ratio(ranging from 15 to 25 L/m3) and the high gravity factor(ranging from 36 to 126) on the removal of H2 S were studied by means of the Box-Behnken design(BBD) under response surface methodology(RSM). The overall results have demonstrated that the BBD with an experimental design can be used effectively in the optimization of the desulfurization process. The optimal conditions based on both individualized and combined responses(at a Fe3+ ion concentration of 0.16 mol/L, a liquid-gas volume ratio of 20.67 L/m3 and a high gravity factor of 87) were found. Under this optimum condition, the desulfurization efficiency could reach 98.81% when the H2 S concentration was 7 g/m3 in APG. In this work, the sulfur product was analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and the energy dispersive X-ray spectrometer(EDX). The results of analysis show that the sulfur is made of the high-purity orthorhombic crystals, which are advantageous to environmental conservation.
基金Project supported by the Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education,China
文摘Au/γ-Al2O3 catalysts were prepared by deposition-precipitation method for the catalytic combustion of low concentration alcohol streams(methanol,ethanol,iso-propanol and n-propanol).The catalysts were characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffractometry(XRD) and energy dispersive X-ray micro analysis(EDS) techniques.The XPS results showed that there was only Au0 on the surface of catalysts.The XRD patterns showed that Au was presumably highly dispersed over γ-Al2O3.The temperatures for complete conversion of methanol,ethanol,iso-propanol and n-propanol with concentration of 2.0 g/m3 were 60,155,170 and 137 ℃,respectively,but they were completely mineralized into CO2 and H2O at 60,220,260 and 217 ℃ respectively over the optimized catalyst.The activity of the catalyst was stable in 130 h.The kinetics for the catalytic methanol elimination followed quasi-first order reaction expressed as r=0.652 8c0+0.084 2.The value of apparent activation energy is 54.7 kJ/mol in the range of reaction temperature.
基金Project(2013GK3021)supported by the Science and Technology Plan of Hunan Province,ChinaProject supported by Young Teacher Growth Plan of Hunan University,China
文摘Al-Si/15%SiCp(volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy(OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10-220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy(SEM) and energy-dispersive X-ray microanalysis(EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiCp composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiCp and Al-13Si/15%SiCp composites, while Al-20Si/15%SiCp presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.
基金supported by the Soil Science department, faculty of Agriculture,University of Guilan
文摘In order to characterize various micromorphologic properties of two forest soils derived from different parent rocks in Lahijan, and use the data collected from micromorphological analysis to interpret dominant pedogenic processes. Two representative soil pedons, granite (P1) and andesitic basalt (P2) were selected in a mountain landform with northwest aspect. Samples for thin section preparation were taken from each horizon by Kubiena boxes or clods. Micromorphological analysis of soils derived from these two soil pedons in eastern part of Lahijan (northern Iran) were conducted based on the physicochemical and mineralogical data. Micromorphological properties were characterized using a polarized light microscope under plain and cross light. Thin section study indicated that the nature of the parent material clearly affected the content of clay formation. It also showed that clay accumulation in the Bt horizons was not only due to clay illuviation (argillan), but that strong in situ weathering of primary minerals also contributed to the enrichment of clay in soils derived from andesitic basalt. Comparing the results of clay mineralogy obtained from X-ray diffraction (XRD) with microscopic studies revealed that birefringence fabric (b-fabric) of the groundmass was partly striated due to smectitic minerals in soil of andesitic basalt (Hapludalf), whereas speckled birefringence fabric was dominant in soil of granite (Udorthent) because of the absence of these minerals. We speculate that pores of skeletal fragments or microcracks in P1 were a place for illuvial clay protection. However, the main factor for flluvial clay film disruption (striation anddeformation) was biological activity (faunal turbation and root pressure) in P1 and expandable minerals and faunal turbation in P2.
基金Project(J12LA53)supported by Shangdong Provincial Higher Education Science and Technology Program,ChinaProject(KZJ-48)supported by the Science and Technology Development Program of Qingdao,China
文摘An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The coating layer is composed of AI phase and exhibits superior corrosion resistance. The formation of the coating is mainly attributed to the obstruction of expansion of the transition zone by primarily solidified Mg]7All2 during rapid cooling, and the diffusion is restricted in a thin layer. These results show that droplet spraying is a promising way to protect magnesium by using corrosion-resistant materials available now.
基金Projects(BK2011243,BK2012156) supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(20123227120021) supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China+3 种基金Project(KFJJ201105) supported by the Opening Project of State key Laboratory of Electronic Thin Films and Integrated Devices,ChinaProject(10KJD430002) supported by the Universities Natural Science Research Project of Jiangsu Province,ChinaProject(13KJB430006) supported by the Application Program for Basic Research of Changzhou,ChinaProject supported by the Industrial Center of Jiangsu University Undergraduate Practice-Innovation Training Project,China
文摘ZnO-Bi2O3-based varistor ceramics doped with EU2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900-1000 ℃ for 2 h. XRD and SEM were applied to determine the phases and microstructure of the varistor ceramics. A DC parameter instrument was applied to investigate the electronic properties and V-I characteristics. The XRD analysis of Eu2O3-doped ZnO-Bi2O3-based varistor ceramics shows that the ZnO, Eu-containing Bi-rich, Zn7Sb2O12-type spinel and Zn2Bi3Sb3O14-type which is the pyrochlore phase are present. With increasing Eu2O3 content, the average size of ZnO grain firstly decreases and then increases. The grain boundary defect model was particularly used to explain the excellent nonlinearity of ZnO-Bi2O3-based varistor ceramics with the addition of0.1% Eu2O3 and sintered at 950 ℃.
文摘The effect of precipitation on the internal friction(IF)of AZ91 magnesium alloy was investigated by using X-ray diffraction(XRD)analysis,scanning electron microscope(SEM)observation,and dynamic mechanical analysis(DMA).Six different states of alloy were prepared by applying different heat treatment processes:as-cast,in-complete solid solution,complete solid solution,micro-precipitation,continuous precipitation and continuous-discontinuous precipitation.It was found that the internal friction of in-completely solid-solutionized,completely solid-solutionized and micro-precipitated specimens showed a similar characteristic,and the grain boundary relaxation is completed depressed due to the Al atoms supersaturated in theα-Mg solution.However,a thermal relaxation internal friction peak was observed for continuously precipitated and continuously-discontinuously precipitated specimens at around 438 K and frequency of about 1 Hz,which was attributed to the grain boundaries relaxation.Furthermore,it was found that the relaxation of theβ-Mg17Al12/α-Mg phase interfaces should give its contribution to the background internal friction in the as-cast,continuously precipitated and continuously-discontinuously precipitated specimens.
基金financial support from the National Natural Science Foundation of China(Nos.51074166,51104128,51322401 and 51204159)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120095110013)+1 种基金the Science and Technology Projects of Urban and Rural Housing Ministry of Construction of China(No.2011-k3-5)the‘‘Blue Project’’of Jiangsu Province are greatly appreciated
文摘The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of tem- perature on mudstone composition and fracture mechanism were studied from a meso-structural per- spective, and the relationship between meso-structure and macro-mechanical characteristics at high temperature was revealed. The findings demonstrated that the fluctuation in diffraction intensity of kao- linite in the mudstone caused the fluctuation in its mechanical properties. The overall structure under- went a phase change around 600℃, which led to the sudden change in the mechanical properties of mudstone samples. When the temperature reached 600 ℃, the crystalline state worsened and kaolinite disappeared; however, some illite was produced, indicating that the chemical reaction of the structure and sudden drop of bearing capacity of the mudstone. Mudst0ne fracturing at high temperature involves mainly intergranular and transgranular fractures, which are typical in micro-brittle tensile failure. Con- sidering the macro-fracture characteristics of mudstone, the results suggested that macro-fracture under external force corresoonds to the meso-fracture.
基金provided by the National Petroleum and Gas Resources Strategic Area Selection Survey & Evaluation projects in 2005,is gratefully acknowledged.
文摘In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope(SEM)and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions.
基金financially supported by the National Major Special Projects of China (No. 2011ZX05005-002-009HZ)the Natural Science Foundation Project of CQ CSTC of China (No. cstc2012jjA90009)+1 种基金the Research Foundation of Chongqing University of Science & Technology of China (Nos. CK20111312, CK2013Z04)the Program of Educational Reform of Chongqing University of Science & Technology of China (No. 201424).
文摘Based on the techniques of X-ray diffraction analysis, identification of the thin sections of core cast, phys- ical analysis and scanning electron microscopy analysis, this paper studied the reservoir characteristics of the Carboniferous strata in Donghe well No.1 of Tarim region. The results show that the reservoir lithology is mainly the fine-grained quartz sandstone with ferrocalcite and pyrite, mud cement-based, the permeability concentrated in 5-40 × 10-3 μm2, a small part of the high permeability up to 150-327 ×10-3 μm2 and porosity ranged from 10% to 20%. The most part of the reservoirs is low perme- ability with a small part of the layer in moderate-high permeability. The types of reservoir space include intergranular pores, intra particle-molding pores, micro-pores and cracks, which mainly are intergranular pores with the pore diameter of 15-200 μm, 95.5μm on average. And the types of the throats are comolex with the main tvne of constricted l:hroats in this area and large contribution to the permeability.
文摘FeCrAI (Ce) stainless steel was functionalized by a conversion treatment in order to allow alumina by diffusion coatings with strong interfacial bonding. The very porous conversion coating produced in a pack aluminization technique had excellent adhesion and was conductive enough to permit conditions favorable for the precipitation of alumina oxyhydroxide during aluminum diffusion coatings. In this work, the bed was prepared as a mixture of A1, NH4C1 and A1203. In the high-activity bed were heat-treated at 1,173 K in an atmosphere made up of team with subsequent air-cooling. The effect of the bed content on the coating was examined. With the high-activity, the desired Fe2Al5 was formed as the outermost coating layer. The coating presented chemical composition gradients suitable for strong adhesion. The improvement of the thermal oxidation behaviour was studied at 1,373 K. Two different aqueous environments, which are (1) NaC1 and (2) H2SO4, are employed for using the technique of potentiodynamic polarization curve. The obtained experimental electrochemical parameters (Ecorr, Jcorr etc,) were used to compare the corrosion resistance of the tested steel state complemented by MEB (electronic scanning microscopy) in combination with dispersive analysis X in energy (EDS) or X ray diffraction indicated that the elements concentration maximum was located in the vicinity of the interface especially in the FeCrAI (Ce) coated by spherical A1203 powder. These results an discussed in terms of an addition effect on the development of the microstructure of oxide films.
文摘This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Gerais State in Brazil. Two soapstone blocks were placed outdoors under tropical environmental conditions for 12 months. A total of 9 filamentous fungal populations were identified on their surfaces, namely Acremomium (cf.) alternatum, Alternaria alternata, Aspergillusfumigatus, Calcarisporium (cf.) arbuscula, Cladosporium cladosporioides, Curvularia lunata, Epicoccum nigrum, Fusarium equiseti and Penicillium citrinum. The gamma radiation assay was then carried out as a test of biocidal action by exposing all fungal populations to the ionizing radiation. The results showed that only the C. cladosporioides species was resistant to this biocidal agent, since it was able to increase its population post exposure. Scanning electron microscopy images identified the microbial colonization on the soapstone blocks and the stone elementar composition was analyzed by energy dispersive X-ray spectrometry. After treatment, there was no structural and aesthetic alteration in the soapstone samples, and evidencing that gamma radiation can be used as a biocidal agent. However, the resistance of the black fungal population indicates caution in the choice of gamma irradiation as biocidal treatment.
文摘A ceramic superconductor compound with composition YBa2(C u3)1-xA gxO6.5x+δhas been prepared experimentally by solid state reaction from principal roots of high purity materials like Y203, BaO, CuO and Ag20. The study was concentrated on the effect of partial substitution of Ag with respect to Cu atoms by the ratios (x = 0, 1, 0.2, 0.3, 0.4 and 0.5) through different analysis and measurements. X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Resistivity measurement is play an important role to show the improvement on high superconducting phase. It was found that the best substituted value of (x = 0.5) investigated a favor value of Tc equal nearly to (123 K), due to more excess of Ag atoms in the structure. X-ray diffraction showed an orthorhombic structure related to high-To phase with high stability through diminishing some peaks related to low temperature superconducting phase, that was related to presence of multiphase derivative from YBCO-phase. SEM pictures give us more details on the surface morphology, grain and grain boundaries, it gives an indication on successful of sintering process, the last one is very important in forming superconducting phase.