Operando X-ray diffraction(XRD)is an important characterization tool for real-time monitoring of structural changes in materials under different reaction conditions.In this study,we developed a laboratory-based diffra...Operando X-ray diffraction(XRD)is an important characterization tool for real-time monitoring of structural changes in materials under different reaction conditions.In this study,we developed a laboratory-based diffractometer that could capture a full XRD spectrum within 10 s.The instrument has several advanced features.First,it uses a Ga–In alloy metal-jet X-ray source,thereby achieving high X-ray flux with a brightness of up to 3.0×10^(10) photons/(s·mm^(2)·mrad2).Second,it employs an ellipsoidal mirror with a multilayer coating to produce quasi-parallel monochromatic light characterized by a divergence of 0.6 mrad and an energy resolution of 5.9×10^(−3).Third,it is equipped with a high-efficiency,high-signal-to-noise-ratio Pilatus 3R 1M detector for collecting diffraction signals.These features make the developed instrument applicable in studying rapid phase transitions in lithium-ion batteries,especially under extremely fast charge–discharge conditions.The data quality was comparable to that of synchrotron radiation XRD.展开更多
We fabricated the spheroid neutron diffractometer with 79 neutron detector rings using the transparent rubber sheet type Eu:LiCaAlF6 scintillators and wavelength-shifting fibers.We confirmed that the fabricated detect...We fabricated the spheroid neutron diffractometer with 79 neutron detector rings using the transparent rubber sheet type Eu:LiCaAlF6 scintillators and wavelength-shifting fibers.We confirmed that the fabricated detector shows a clear neutron peak and can discriminate neutron and gamma-ray events in a signal pulse spectrum.We additionally checked that the fabricated diffractometer can detect a neutron diffraction peak of ferrite powder at Kyoto University Accelerator-driven Neutron Source.Consequently,it can be expected that crystal structural analysis will be possible even by small accelerator neutron sources.展开更多
INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes ...INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes of ion exchange, absorption, desorption and flocculation in the estuary.展开更多
The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor,due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture...The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor,due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture diffractometer has high neutron intensity, moderate resolution and is mainly applied to study texture in commonly used industrial materials and engineering components. In this paper, the design and characteristics of this instrument are described. The results for calibration with neutrons and quantitative texture analysis of zirconium alloy plate are presented. The comparison of texture measurements with the results obtained in HIPPO at LANSCE and Kowari at ANSTO illustrates the reliability of the texture diffractometer.展开更多
Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signali...Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.展开更多
The mechanical properties and acoustic emission characteristics of thick hard roof sandstone were investigated. Samples were taken from the 30.87-m thick sandstone roof in a mine in the Shengdong coal field, China. Fi...The mechanical properties and acoustic emission characteristics of thick hard roof sandstone were investigated. Samples were taken from the 30.87-m thick sandstone roof in a mine in the Shengdong coal field, China. Firstly, the composition and microscopic characteristics were analyzed by XRD and FE-SEM, respectively. Moreover, the indirect tensile test, uniaxial compression test, three axis compression experiment and AE test are carried out by using RMT-150C mechanics experiment system with DSS-8B AE test system. The experiment results indicate that the main framework particles of sandstone are quartz and feldspar, and mainly quartz. Cements are mainly pyrite, kaolinite, chlorite and zeolite cross needle, clinochlore, and clay minerals. The microstructure of sandstone is very dense, with few pores and high cementation degree. The tensile strength, compressive strength and elastic modulus of sandstone are 4.825, 85.313 MPa, 13.814 GPa, respectively, so the sandstone belongs to hard rock. The AE cumulative counts of sandstone can be divided into three phases： relatively flat growth period, rapid growth period and spurt period. The signal strength of AE waveform can be used as a warning signal. In the tensile fracture zone, the warning value is 0.4 mV, and in the compression shear failure zone, it is 4 mV. The numbers of cumulative counts of AE under different stress conditions have obvious difference. Moreover, the growth of cumulative counts of acoustic emission is more obvious when the stress is more than 60% of the peak stress.展开更多
To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted....To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.展开更多
As a kind of lanthanide oxide functional material,Er_(2)O_(3) as aroused widespread scientific interest due to its exceptional properties;however,its humidity sensing performance remains to be explored.Herein,the rati...As a kind of lanthanide oxide functional material,Er_(2)O_(3) as aroused widespread scientific interest due to its exceptional properties;however,its humidity sensing performance remains to be explored.Herein,the rational designed Er_(2)O_(3) anospheres were prepared by one-step solvothermal and high-temperature calcined method.The structure and morphology of the samples were analyzed by X-ray diffractometer(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM),and the effect of calcination temperatures on humidity sensing characteristics was also investigated.展开更多
Al-doped ZnO(AZO) has been used as an electron transport and hole blocking buffer layer in inverted organic solar cells(IOSCs). In this paper, the AZO morphology, optical and structural properties and IOSCs performanc...Al-doped ZnO(AZO) has been used as an electron transport and hole blocking buffer layer in inverted organic solar cells(IOSCs). In this paper, the AZO morphology, optical and structural properties and IOSCs performance are investigated as a function of precursor solution concentration from 0.1 mol/L to 1.0 mol/L. We demonstrate that the device with 0.1 mol/L precursor concentration of AZO buffer layers enhances the short-circuit current and the fill factor of IOSCs simultaneously. The resulting device shows that the power conversion efficiency is improved by 35.6% relative to that of the 1.0 mol/L device, due to the improved surface morphology and transmittance(300–400 nm) of AZO buffer layer.展开更多
Structural stability in terms of the decomposition temperature in LiMn_(2)O_(4) was systematically investigated by a series of high-temperature and high-pressure experiments.LiMn_(2)O_(4) was found to have structural ...Structural stability in terms of the decomposition temperature in LiMn_(2)O_(4) was systematically investigated by a series of high-temperature and high-pressure experiments.LiMn_(2)O_(4) was found to have structural stability up to 5 GPa at room temperature.Under ambient pressure,the compound decomposed at 1300℃.The decomposition temperature decreased with increasing pressure,yielding more complex decomposed products.Below the decomposition temperature,the crystal structure of LiMn_(2)O_(4) varied with pressure.The presented results in this study offer new insights into the thermal and pressure stability of LiMn_(2)O_(4) materials as a cathode for lithium-ion batteries that can operate under extreme conditions.Therefore,these findings may serve as a useful guide for future work for improving lithium-ion batteries.展开更多
We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a convention...We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray radiation.High-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.展开更多
The stainless Fe-Mn-Si shape memory alloy(SMA) coating was prepared on the surface of AISI 304 stainless steel. The principal residual stress measured by the mechanical hole-drilling method indicates that the Fe-Mn-Si...The stainless Fe-Mn-Si shape memory alloy(SMA) coating was prepared on the surface of AISI 304 stainless steel. The principal residual stress measured by the mechanical hole-drilling method indicates that the Fe-Mn-Si SMA cladding specimen possesses a lower residual stress compared with the 304 stainless steel cladding specimen. The mean stress values of the former and the latter on 10-mm-thick substrate are 4.751 MPa and 7.399 MPa, respectively. What's more, their deformation values on 2-mm-thick substrate are about 0° and 15°, respectively. Meanwhile, the variation trend and the value of the residual stress simulated by the ANSYS finite element software consist with experimental results. The X-ray diffraction(XRD) pattern shows ε-martensite exists in Fe-Mn-Si SMA coating, which verifies the mechanism of low residual stress. That's the γ→ε martensite phase transformation, which relaxes the residual stress of the specimen and reduces its deformation in the laser cladding processing.展开更多
The temperature dependences of magnetostriction in Pr（1 x）DyxFe（1.9）（0 ≤ x ≤ 1.0） alloys between 5 K and 300 K were investigated.An unusual decrease of magnetostriction with temperature decreasing was found in...The temperature dependences of magnetostriction in Pr（1 x）DyxFe（1.9）（0 ≤ x ≤ 1.0） alloys between 5 K and 300 K were investigated.An unusual decrease of magnetostriction with temperature decreasing was found in Pr-rich alloys（0 ≤x ≤ 0.2）,due to the change of the easy magnetization direction（EMD）.Dy substitution reduces the magnetostriction in high-magnetic field（10 kOe ≤ H≤90 kOe） at 5 K,while a small amount of Dy substitution（x = 0.05） is beneficial to increasing the magnetostriction in low-magnetic field between 10 K and 50 K.This makes the alloys a potential candidate for low temperature applications.展开更多
The majority of extant reptiles are oviparous and produce eggs with three major components:embryo,yolk,and eggshell.The eggshell is species-specific and more diverse in squamate reptiles than in other amniote taxa.Her...The majority of extant reptiles are oviparous and produce eggs with three major components:embryo,yolk,and eggshell.The eggshell is species-specific and more diverse in squamate reptiles than in other amniote taxa.Here,we study the crystal structure,chemical composition,and bonding states of the eggshell of the green crested lizard Bronchocela cristatella.X-ray diffractometer(XRD)analysis showed the existence of two clearly defined and distinguishable crystalline phases,aragonite and calcite.Using the XRD data and a unit cell refinement routine,we identified two sets of cell parameters:a=4.956 A,b=7.965 A,and c=5.734 A for the aragonite phase;a=4.987 A,b=4.987 A,and c=17.056 A for the calcite structure.We used x-ray photoelectron spectroscopy to examine detailed elemental composition and bonding states and found that the eggshell was composed primarily of elements C,N,Ca,and O,with C,N and O bonded to various types of hybridization in the protein of the eggshell membrane.The Ca:C:O ratio for the calcium carbonate yielded a value of-7:8:21,which is close to the expected stoichiometric value of CaCO3.展开更多
Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force micr...Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films （RMS： from 0.503 to 2.849 nm）. The presence of obviously-broadened peaks for diffraction planes （111） suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190-260 nm increased.展开更多
Impact of the process of modification on graphite structure at the application of fluorine-containing oligomer-FDS （chloroperfluorododecylfluoro sulfate） has been studied. It was shown that during this process graph...Impact of the process of modification on graphite structure at the application of fluorine-containing oligomer-FDS （chloroperfluorododecylfluoro sulfate） has been studied. It was shown that during this process graphite structure does not change. Only particles of FDS are destructed into monolayers, which are spread in graphite intercrystalline voids. At the mechanical impact it protects graphite from destruction and correspondingly, improveing some of its tribotechnical characteristics.展开更多
Raffia fibres are made from fibrous branches and leaves of Raffia palm. The membrane on the underside of each individual frond leaf is taken off to create a long thin fiber. They are usually waste materials which caus...Raffia fibres are made from fibrous branches and leaves of Raffia palm. The membrane on the underside of each individual frond leaf is taken off to create a long thin fiber. They are usually waste materials which cause a great environmental degradation. The characterization of Raffia palm fibers/ particles was investigated through X-ray diffractometer (XRD), thermogravimetric analysis (TGA/DTA), Fourier transform infrared spectrometry (FTIR), Scanning electron mi croscope with energy dispersive spectrometer (SEM/EDS) and Atomic force microscope (AFM). The various results obtained are equivalent to those of other agro-waste materials generally used in roofing sheets composites production. Hence, this work shows that Raffia palm fibers/particles can be a useful material for cement mortar composites production which can be used for production of roofing sheets.展开更多
Microcrystalline cellulose (MCC) was pretreated by using ionic liquids (ILs)-water mixtures solvent with solid acid catalysts. Different amount of water was considerate as the main variable. The peak shift of pretreat...Microcrystalline cellulose (MCC) was pretreated by using ionic liquids (ILs)-water mixtures solvent with solid acid catalysts. Different amount of water was considerate as the main variable. The peak shift of pretreated sample was determined by FT-IR related to the water content. The XRD was applied to characterize the change in MCC crystalline structure. Thermal decomposition technique was applied to investigate the thermal stability of pretreated MCC. The result indicated that three state of samples were occurred in pretreated MCC sample which was related the amount of water in ILs mixture system. XRD result suggested that the raw sample was distorted and transformed into a less ordered intermediate structure and the smaller crystallite size in lump state sample was obtained which could lead to lower thermal stability. This study revealed the physical chemicals properties, characteristic of molecular structures in MCC using ILs-water mixtures.展开更多
A Cr-Ni-Mo overlayer was deposited on the surface of compacted graphite iron（CGI）by the plasma transferred arc（PTA）alloying technique.The microstructure of Cr-Ni-Mo overlayer was characterized by optical microscop...A Cr-Ni-Mo overlayer was deposited on the surface of compacted graphite iron（CGI）by the plasma transferred arc（PTA）alloying technique.The microstructure of Cr-Ni-Mo overlayer was characterized by optical microscopy（OM）,scanning electron microscopy（SEM）equipped with energy dispersive spectroscopy（EDS）,and X-ray diffractometer（XRD）.Results show that the cross-section consists of four regions：alloying zone（AZ）,molten zone（MZ）,heat affected zone（HAZ）,and the substrate（SUB）.The microstructure of AZ mainly consists of cellularγ-（Fe,Ni）solid solution,residual austenite and a network of eutectic Cr7C3 carbide while the MZ area has a typical feature of white cast iron（M3C-type cementite）.The martensite/ledeburite double shells are observed in the HAZ.With decreasing the concentration of Cr-Ni-Mo alloys,the fracture mode changes from ductile in the AZ to brittle in the MZ.The maximum hardness of the AZ（450 HV0.2）is lower than that of the MZ（800 HV0.2）.The eutectic M3 C and M7C3 carbides increase the microhardness,while the austenite decreases that of the AZ.展开更多
Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase min...Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.展开更多
基金supported by“2020 Special Fund for Key Technology and Equipment Development of Major Science and Technology Infrastructure”from the Development and Reform Commission of Shenzhensupport from National Natural Science Foundation of China(Grant No.52103365)Guangdong Innovative and Entrepreneurial Research Team Program(Grant No.2021ZT09L227).
文摘Operando X-ray diffraction(XRD)is an important characterization tool for real-time monitoring of structural changes in materials under different reaction conditions.In this study,we developed a laboratory-based diffractometer that could capture a full XRD spectrum within 10 s.The instrument has several advanced features.First,it uses a Ga–In alloy metal-jet X-ray source,thereby achieving high X-ray flux with a brightness of up to 3.0×10^(10) photons/(s·mm^(2)·mrad2).Second,it employs an ellipsoidal mirror with a multilayer coating to produce quasi-parallel monochromatic light characterized by a divergence of 0.6 mrad and an energy resolution of 5.9×10^(−3).Third,it is equipped with a high-efficiency,high-signal-to-noise-ratio Pilatus 3R 1M detector for collecting diffraction signals.These features make the developed instrument applicable in studying rapid phase transitions in lithium-ion batteries,especially under extremely fast charge–discharge conditions.The data quality was comparable to that of synchrotron radiation XRD.
文摘We fabricated the spheroid neutron diffractometer with 79 neutron detector rings using the transparent rubber sheet type Eu:LiCaAlF6 scintillators and wavelength-shifting fibers.We confirmed that the fabricated detector shows a clear neutron peak and can discriminate neutron and gamma-ray events in a signal pulse spectrum.We additionally checked that the fabricated diffractometer can detect a neutron diffraction peak of ferrite powder at Kyoto University Accelerator-driven Neutron Source.Consequently,it can be expected that crystal structural analysis will be possible even by small accelerator neutron sources.
基金The project was supported by the National Natural Science Foundation of China.
文摘INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes of ion exchange, absorption, desorption and flocculation in the estuary.
基金Supported by National Nature Science Foundation of China(11105231,11205248,51327902)International Atomic Energy Agency-TC program(CPR0012)
文摘The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor,due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture diffractometer has high neutron intensity, moderate resolution and is mainly applied to study texture in commonly used industrial materials and engineering components. In this paper, the design and characteristics of this instrument are described. The results for calibration with neutrons and quantitative texture analysis of zirconium alloy plate are presented. The comparison of texture measurements with the results obtained in HIPPO at LANSCE and Kowari at ANSTO illustrates the reliability of the texture diffractometer.
基金supported by the Russian Science Foundation grant(No.22-15-00120)supported by the grant(No.21-2-10-59-1)from the Foundation for the Development of Theoretical Physics and Mathematics BASIS.
文摘Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.
文摘The mechanical properties and acoustic emission characteristics of thick hard roof sandstone were investigated. Samples were taken from the 30.87-m thick sandstone roof in a mine in the Shengdong coal field, China. Firstly, the composition and microscopic characteristics were analyzed by XRD and FE-SEM, respectively. Moreover, the indirect tensile test, uniaxial compression test, three axis compression experiment and AE test are carried out by using RMT-150C mechanics experiment system with DSS-8B AE test system. The experiment results indicate that the main framework particles of sandstone are quartz and feldspar, and mainly quartz. Cements are mainly pyrite, kaolinite, chlorite and zeolite cross needle, clinochlore, and clay minerals. The microstructure of sandstone is very dense, with few pores and high cementation degree. The tensile strength, compressive strength and elastic modulus of sandstone are 4.825, 85.313 MPa, 13.814 GPa, respectively, so the sandstone belongs to hard rock. The AE cumulative counts of sandstone can be divided into three phases： relatively flat growth period, rapid growth period and spurt period. The signal strength of AE waveform can be used as a warning signal. In the tensile fracture zone, the warning value is 0.4 mV, and in the compression shear failure zone, it is 4 mV. The numbers of cumulative counts of AE under different stress conditions have obvious difference. Moreover, the growth of cumulative counts of acoustic emission is more obvious when the stress is more than 60% of the peak stress.
基金Project (No. 2011DFA72730-202) supported by the Research Project of US-China Clean Energy Research Center
文摘To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.
基金financially supported by the National Natural Science Foundation of China(No.21771060)the International Science&Technology Cooperation Program of China(No.2016YFE0115100)+1 种基金Heilongjiang Provincial Natural Science Foundation of China(No.JQ2021B002)the Reform and Development Fund Project of Local University supported by the Central Government,Heilongjiang Touyan Innovation Team Program。
文摘As a kind of lanthanide oxide functional material,Er_(2)O_(3) as aroused widespread scientific interest due to its exceptional properties;however,its humidity sensing performance remains to be explored.Herein,the rational designed Er_(2)O_(3) anospheres were prepared by one-step solvothermal and high-temperature calcined method.The structure and morphology of the samples were analyzed by X-ray diffractometer(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM),and the effect of calcination temperatures on humidity sensing characteristics was also investigated.
基金supported by the National Natural Science Foundation of China(No.61377031)the Scientific Research Foundation of Zhejiang Ocean University(No.Q1444)
文摘Al-doped ZnO(AZO) has been used as an electron transport and hole blocking buffer layer in inverted organic solar cells(IOSCs). In this paper, the AZO morphology, optical and structural properties and IOSCs performance are investigated as a function of precursor solution concentration from 0.1 mol/L to 1.0 mol/L. We demonstrate that the device with 0.1 mol/L precursor concentration of AZO buffer layers enhances the short-circuit current and the fill factor of IOSCs simultaneously. The resulting device shows that the power conversion efficiency is improved by 35.6% relative to that of the 1.0 mol/L device, due to the improved surface morphology and transmittance(300–400 nm) of AZO buffer layer.
基金by the National Natural Science Foundation of China(Grant No.12074273)the Doctoral Research Fund of Southwest University of Science and Technology(Grant No.20zx7136).
文摘Structural stability in terms of the decomposition temperature in LiMn_(2)O_(4) was systematically investigated by a series of high-temperature and high-pressure experiments.LiMn_(2)O_(4) was found to have structural stability up to 5 GPa at room temperature.Under ambient pressure,the compound decomposed at 1300℃.The decomposition temperature decreased with increasing pressure,yielding more complex decomposed products.Below the decomposition temperature,the crystal structure of LiMn_(2)O_(4) varied with pressure.The presented results in this study offer new insights into the thermal and pressure stability of LiMn_(2)O_(4) materials as a cathode for lithium-ion batteries that can operate under extreme conditions.Therefore,these findings may serve as a useful guide for future work for improving lithium-ion batteries.
基金Supported by the National Natural Science Foundation of China under Grant No 40872033the Fundamental Research Funds for the Central Universities.
文摘We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray radiation.High-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.
基金supported by the Fundamental Research Funds for the Central Universities of China(No.3132016354)
文摘The stainless Fe-Mn-Si shape memory alloy(SMA) coating was prepared on the surface of AISI 304 stainless steel. The principal residual stress measured by the mechanical hole-drilling method indicates that the Fe-Mn-Si SMA cladding specimen possesses a lower residual stress compared with the 304 stainless steel cladding specimen. The mean stress values of the former and the latter on 10-mm-thick substrate are 4.751 MPa and 7.399 MPa, respectively. What's more, their deformation values on 2-mm-thick substrate are about 0° and 15°, respectively. Meanwhile, the variation trend and the value of the residual stress simulated by the ANSYS finite element software consist with experimental results. The X-ray diffraction(XRD) pattern shows ε-martensite exists in Fe-Mn-Si SMA coating, which verifies the mechanism of low residual stress. That's the γ→ε martensite phase transformation, which relaxes the residual stress of the specimen and reduces its deformation in the laser cladding processing.
基金Project supported by the National Natural Science Foundation of China(Grant No.U1232210)the Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant No.2015GXNSFBA139020)the Enhancement of the Basic Ability of Teachers of Guangxi Zhuang Autonomous Region,China(Grant No.KY2016YB068)
文摘The temperature dependences of magnetostriction in Pr（1 x）DyxFe（1.9）（0 ≤ x ≤ 1.0） alloys between 5 K and 300 K were investigated.An unusual decrease of magnetostriction with temperature decreasing was found in Pr-rich alloys（0 ≤x ≤ 0.2）,due to the change of the easy magnetization direction（EMD）.Dy substitution reduces the magnetostriction in high-magnetic field（10 kOe ≤ H≤90 kOe） at 5 K,while a small amount of Dy substitution（x = 0.05） is beneficial to increasing the magnetostriction in low-magnetic field between 10 K and 50 K.This makes the alloys a potential candidate for low temperature applications.
文摘The majority of extant reptiles are oviparous and produce eggs with three major components:embryo,yolk,and eggshell.The eggshell is species-specific and more diverse in squamate reptiles than in other amniote taxa.Here,we study the crystal structure,chemical composition,and bonding states of the eggshell of the green crested lizard Bronchocela cristatella.X-ray diffractometer(XRD)analysis showed the existence of two clearly defined and distinguishable crystalline phases,aragonite and calcite.Using the XRD data and a unit cell refinement routine,we identified two sets of cell parameters:a=4.956 A,b=7.965 A,and c=5.734 A for the aragonite phase;a=4.987 A,b=4.987 A,and c=17.056 A for the calcite structure.We used x-ray photoelectron spectroscopy to examine detailed elemental composition and bonding states and found that the eggshell was composed primarily of elements C,N,Ca,and O,with C,N and O bonded to various types of hybridization in the protein of the eggshell membrane.The Ca:C:O ratio for the calcium carbonate yielded a value of-7:8:21,which is close to the expected stoichiometric value of CaCO3.
基金Funded by the Fund of the Science and Technology on Plasma Physics Laboratory(No.9140C680501110C6803)
文摘Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films （RMS： from 0.503 to 2.849 nm）. The presence of obviously-broadened peaks for diffraction planes （111） suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190-260 nm increased.
文摘Impact of the process of modification on graphite structure at the application of fluorine-containing oligomer-FDS （chloroperfluorododecylfluoro sulfate） has been studied. It was shown that during this process graphite structure does not change. Only particles of FDS are destructed into monolayers, which are spread in graphite intercrystalline voids. At the mechanical impact it protects graphite from destruction and correspondingly, improveing some of its tribotechnical characteristics.
文摘Raffia fibres are made from fibrous branches and leaves of Raffia palm. The membrane on the underside of each individual frond leaf is taken off to create a long thin fiber. They are usually waste materials which cause a great environmental degradation. The characterization of Raffia palm fibers/ particles was investigated through X-ray diffractometer (XRD), thermogravimetric analysis (TGA/DTA), Fourier transform infrared spectrometry (FTIR), Scanning electron mi croscope with energy dispersive spectrometer (SEM/EDS) and Atomic force microscope (AFM). The various results obtained are equivalent to those of other agro-waste materials generally used in roofing sheets composites production. Hence, this work shows that Raffia palm fibers/particles can be a useful material for cement mortar composites production which can be used for production of roofing sheets.
文摘Microcrystalline cellulose (MCC) was pretreated by using ionic liquids (ILs)-water mixtures solvent with solid acid catalysts. Different amount of water was considerate as the main variable. The peak shift of pretreated sample was determined by FT-IR related to the water content. The XRD was applied to characterize the change in MCC crystalline structure. Thermal decomposition technique was applied to investigate the thermal stability of pretreated MCC. The result indicated that three state of samples were occurred in pretreated MCC sample which was related the amount of water in ILs mixture system. XRD result suggested that the raw sample was distorted and transformed into a less ordered intermediate structure and the smaller crystallite size in lump state sample was obtained which could lead to lower thermal stability. This study revealed the physical chemicals properties, characteristic of molecular structures in MCC using ILs-water mixtures.
文摘A Cr-Ni-Mo overlayer was deposited on the surface of compacted graphite iron（CGI）by the plasma transferred arc（PTA）alloying technique.The microstructure of Cr-Ni-Mo overlayer was characterized by optical microscopy（OM）,scanning electron microscopy（SEM）equipped with energy dispersive spectroscopy（EDS）,and X-ray diffractometer（XRD）.Results show that the cross-section consists of four regions：alloying zone（AZ）,molten zone（MZ）,heat affected zone（HAZ）,and the substrate（SUB）.The microstructure of AZ mainly consists of cellularγ-（Fe,Ni）solid solution,residual austenite and a network of eutectic Cr7C3 carbide while the MZ area has a typical feature of white cast iron（M3C-type cementite）.The martensite/ledeburite double shells are observed in the HAZ.With decreasing the concentration of Cr-Ni-Mo alloys,the fracture mode changes from ductile in the AZ to brittle in the MZ.The maximum hardness of the AZ（450 HV0.2）is lower than that of the MZ（800 HV0.2）.The eutectic M3 C and M7C3 carbides increase the microhardness,while the austenite decreases that of the AZ.
文摘Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of <sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.
