Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepent...Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepentamine(TEPA) for CO2capture. The TEPA impregnated IG-MWCNTs were characterized with various experimental methods including N2adsorption/desorption isotherms, elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. Both the adsorption isotherms of IGMWCNTs-n and the isosteric heats of different adsorption capacities were obtained from experiments. TEPA impregnated IG-MWCNTs were also shown to have high CO2adsorption capacity comparable to that of TEPA impregnated P-MWCNTs. The adsorption capacity of IG-MWCNTs based adsorbents was in the range of 2.145 to 3.088 mmol/g, depending on adsorption temperatures. Having the advantages of low-cost and high adsorption capacity, TEPA impregnated IG-MWCNTs seem to be a promising adsorbent for CO2capture from flue gas.展开更多
The forms and structures of the phases in Fe-Ni-Co-Nb-Ti-Si low expansion superal-loys have been studied using analytical electron microscopy, high resolution electron microscopy, chemical phase analysis, X-ray diffra...The forms and structures of the phases in Fe-Ni-Co-Nb-Ti-Si low expansion superal-loys have been studied using analytical electron microscopy, high resolution electron microscopy, chemical phase analysis, X-ray diffraction, etc. The effects of yttrium on the microstructures and properties in the superalloys have also been investigated. The results reveal that trace yttrium mainly located in the platelet precipitates makes the crystal structure changed. The platelet precipitates become smaller, denser and rather homogeneous with appropriate yttrium addition. Compared with the conventional low expansion superalloy, the misfit of the platelet phase with the matrix in the yttrium-containing low expansion superalloy decreases from 0.7% to 0.07%, which indicates very low stress at the interface.展开更多
An Al62.5Cu25Fe12.5 quasi-crystalline alloy was prepared by are melting. X-ray diffraction and scanning electron microscopy were used to study the microstructure of the quasi-crystalline alloy. Isothermal weight gain ...An Al62.5Cu25Fe12.5 quasi-crystalline alloy was prepared by are melting. X-ray diffraction and scanning electron microscopy were used to study the microstructure of the quasi-crystalline alloy. Isothermal weight gain of the Al-Cu-Fe quasi-crystal at elevated temperature in dry air was measured by means of a thermal balance and the oxidation behavior was evaluated by oxidation kinetic curves, from which it was deduced that the quasi-crystal exhibits good oxidation resistance. The surface morphologies of the Al-Cu-Fe quasi-crystal after isothermal oxidation at 700°C and 800°C for different times were observed. The oxidation resistance of quasi-crystalline powder and normal crystalline powder in the Al-Cu-Fe system was also quantitatively compared in quantity.展开更多
New high performance grouts with high volume stability and good fluidity were prepared with Portland cement and a multifunctional admixture (MFA). The theological characteristics and mechanical performance of the grou...New high performance grouts with high volume stability and good fluidity were prepared with Portland cement and a multifunctional admixture (MFA). The theological characteristics and mechanical performance of the grouts were investigated. The addition of MFA effectively improves the pseudo-plasticity of the grout. The Ma cone flow time decreases obviously, and the bleeding rate tends to be zero. The deformation behaviors of fresh mixture and hardened grout are systematically studied. Mercury injection method (MIP), scanning electron microscopy (SEM) and X-ray diffractory analysis experiments are used to analyze the microstructure evolution of the grouts, which manifests that the co-action of the early bubble reaction and the latter ettringite crystallization ensure the volume stability throughout the whole hydration process and result in refined pore structure of the grout.展开更多
In this paper, a depth-graded C/W multilayer mirror with broad grazing incident angular range, consisting of three multilayer stacks, each of which has different period thickness d and the layer pair number, was desig...In this paper, a depth-graded C/W multilayer mirror with broad grazing incident angular range, consisting of three multilayer stacks, each of which has different period thickness d and the layer pair number, was designed and fabricated by direct current (DC) magnetron sputtering. For calculating the definite performance of such a mirror, the saturation effects of the interfacial imperfection, such as interface roughness and diffusion, were emerged. The reflectivity of the mirror was measured by the X-ray diffraction (XRD) instrument at Cu Kα radiation (λ = 0.154 nm), the measured reflectivity was about 30% in a broad grazing incident angular range (0.55°-0.85°). By the fitting data, the thickness of each layer is almost same as the one designed and the roughness in the multilayer is about 0.85 nm, which is larger than the prospective value of 0.5 nm.展开更多
A series of Mo/Si multilayers with the same periodic length and different periodic number were prepared by magnetron sputtering, whose top layers were respectively Mo layer and Si layer. Periodic length and interface ...A series of Mo/Si multilayers with the same periodic length and different periodic number were prepared by magnetron sputtering, whose top layers were respectively Mo layer and Si layer. Periodic length and interface roughness of Mo/Si multilayers were determined by small angle X-ray diffraction （SAXRD）. Surface roughness change curve of Mo/Si multilayer with increasing layer number was studied by atomic force microscope （AFM）. Soft X-ray reflectivity of Mo/Si multilayers was measured in National Synchrotron Radiation Laboratory （NSRL）. Theoretical and experimental results show that the soft X-ray reflectivity of Mo/Si multilayer is mainly determined by periodic number and interface roughness, surface roughness has little effect on reflectivity.展开更多
Ultra-short-period W/C multilayers having periodic thickness range of 1.15-3.01 nm have been fabricated for soft X-ray optics using the high vacuum direct current (DC) magnetron sputtering system. These multilayers we...Ultra-short-period W/C multilayers having periodic thickness range of 1.15-3.01 nm have been fabricated for soft X-ray optics using the high vacuum direct current (DC) magnetron sputtering system. These multilayers were characterized by low-angle X-ray diffraction (LAXRD) and transmission electron microscope (TEM). The results show that the multilayer thin films with periodic thickness more than 1.5 nm have clear W-C interface and low roughness. But the structure of the periodic thickness below 1.5 nm is not clear. Finally, three ways to improve the performance of the multilayers are suggested.展开更多
Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduce...Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings（ARCs） simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.展开更多
BiOx films are prepared by reactive direct current （DC） magnetron sputtering from a metallic bismuth target in Ar ＋O2 with different O2/Ar ratios. It is found that the optical property of BiOx films is sensitive to...BiOx films are prepared by reactive direct current （DC） magnetron sputtering from a metallic bismuth target in Ar ＋O2 with different O2/Ar ratios. It is found that the optical property of BiOx films is sensitive to O2/Ar ratios and the films deposited at O2/Ar ratio of 0.5 have the best reflectivity contrast under the same conditions. The structure and optical characteristics of the films are studied by X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and spectrophotometer. As revealed by investigations, the phase transition is mainly responsible for the change of optical properties. The static test results indicate that the BiO~ films have good writing sensitivity for blue laser beams. A high reflectivity contrast of about 52% at a writing power of 11 mW and writing pulse width of 800 ns is obtained. In addition, the films demonstrate good stability after being read for 10000 times.展开更多
Using two-step method InP epilayers were grown on GaAs（100） substrates by low-pressure metalorganic chemical vapor deposition （LP-MOCVD）. X-ray diffraction （XRD） and room-temperature （RT） photolu- minescence ...Using two-step method InP epilayers were grown on GaAs（100） substrates by low-pressure metalorganic chemical vapor deposition （LP-MOCVD）. X-ray diffraction （XRD） and room-temperature （RT） photolu- minescence （PL） were employed to characterize the quality of InP epilayer. The best scheme of growing InP/GaAs（100） heterostructures was obtained by optimizing the initial low-temperature （LT） InP growth conditions, investigating the effects of thermal cycle annealing （TCA） and strained layer superlattice （SLS） on InP epilayers. Compared with annealing, 10-periods Ga0.1In0.9P/InP SLS inserted into InP epilayers can improve the quality of epilayers dramatically, by this means, for 2.6-#m-thick heteroepitaxial InP, the full-widths at half-maximum （FWHMs） of XRD ω and ω-28 scans are 219 and 203 arcsec, respectively, the RT PL spectrum shows the band edge transition of InP, the FWHM is 42 meV. In addition, the successful growth of InP/In0.53Ga0.47As MQWs on GaAs（100） substrates indicates the quality of device demand of InP/GaAs heterostructures.展开更多
Indium oxide(In_2O_3) films were prepared on Al_2O_3(0001) substrates at 700 °C by metal-organic chemical vapor deposition(MOCVD).Then the samples were annealed at 800 °C,900 °C and 1 000 °C,respec...Indium oxide(In_2O_3) films were prepared on Al_2O_3(0001) substrates at 700 °C by metal-organic chemical vapor deposition(MOCVD).Then the samples were annealed at 800 °C,900 °C and 1 000 °C,respectively.The X-ray diffraction(XRD) analysis reveals that the samples were polycrystalline films before and after annealing treatment.Triangle or quadrangle grains can be observed,and the corner angle of the grains becomes smooth after annealing.The highest Hall mobility is obtained for the sample annealed at 900 °C with the value about 24.74 cm^2·V^(-1)·s^(-1).The average transmittance for the films in the visible range is over 90%.The optical band gaps of the samples are about 3.73 e V,3.71 e V,3.70 eV and 3.69 eV corresponding to the In_2O_3 films deposited at 700 °C and annealed at 800 °C,900 °C and 1 000 °C,respectively.展开更多
A series of thin Ag films with different thicknesses grown under identical conditions are analyzed by means of spectrophotometer. From these measurements the values of refractive index and extinction coefficient are c...A series of thin Ag films with different thicknesses grown under identical conditions are analyzed by means of spectrophotometer. From these measurements the values of refractive index and extinction coefficient are calculated. The films are deposited onto BK7 glass substrates by direct current （DC） magnetron sputtering. It is found that the optical properties of the Ag films can be affected by films thickness. Below critical thickness of 17 nm, which is the thickness at which Ag films form continuous films, the optical properties and constants vary significantly with thickness increasing and then tend to a stable value up to about 40 nm. At the same time, X-ray diffraction measurement is carried out to examine the microstructure evolution of Ag films as a function of films thickness. The relation between optical properties and microstructure is discussed.展开更多
Different up-conversion luminescent spectra of Er^3＋ ions were observed in the oxyfluoride glass-ceramics. The ratio of two fluorides in the original compositions was modified in order to form different nanocrystals....Different up-conversion luminescent spectra of Er^3＋ ions were observed in the oxyfluoride glass-ceramics. The ratio of two fluorides in the original compositions was modified in order to form different nanocrystals. The intensity of up-conversion luminescence increased sharply when the ratio of PbF2 and CdF2 was 40：10. The data of differential thermal analysis and X-ray diffraction were used to explain the optimization fluoride ratio. The intensity of up-conversion luminescence is not only decided by the crystallizability but also mainly related with the stoiehiometric proportion of fluoride nanocrystals in the glass-ceramics.展开更多
基金supported by Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ12E08002)
文摘Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepentamine(TEPA) for CO2capture. The TEPA impregnated IG-MWCNTs were characterized with various experimental methods including N2adsorption/desorption isotherms, elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. Both the adsorption isotherms of IGMWCNTs-n and the isosteric heats of different adsorption capacities were obtained from experiments. TEPA impregnated IG-MWCNTs were also shown to have high CO2adsorption capacity comparable to that of TEPA impregnated P-MWCNTs. The adsorption capacity of IG-MWCNTs based adsorbents was in the range of 2.145 to 3.088 mmol/g, depending on adsorption temperatures. Having the advantages of low-cost and high adsorption capacity, TEPA impregnated IG-MWCNTs seem to be a promising adsorbent for CO2capture from flue gas.
基金Chinese foundation of aeronautical science( N o.96 G2 10 0 3)
文摘The forms and structures of the phases in Fe-Ni-Co-Nb-Ti-Si low expansion superal-loys have been studied using analytical electron microscopy, high resolution electron microscopy, chemical phase analysis, X-ray diffraction, etc. The effects of yttrium on the microstructures and properties in the superalloys have also been investigated. The results reveal that trace yttrium mainly located in the platelet precipitates makes the crystal structure changed. The platelet precipitates become smaller, denser and rather homogeneous with appropriate yttrium addition. Compared with the conventional low expansion superalloy, the misfit of the platelet phase with the matrix in the yttrium-containing low expansion superalloy decreases from 0.7% to 0.07%, which indicates very low stress at the interface.
文摘An Al62.5Cu25Fe12.5 quasi-crystalline alloy was prepared by are melting. X-ray diffraction and scanning electron microscopy were used to study the microstructure of the quasi-crystalline alloy. Isothermal weight gain of the Al-Cu-Fe quasi-crystal at elevated temperature in dry air was measured by means of a thermal balance and the oxidation behavior was evaluated by oxidation kinetic curves, from which it was deduced that the quasi-crystal exhibits good oxidation resistance. The surface morphologies of the Al-Cu-Fe quasi-crystal after isothermal oxidation at 700°C and 800°C for different times were observed. The oxidation resistance of quasi-crystalline powder and normal crystalline powder in the Al-Cu-Fe system was also quantitatively compared in quantity.
文摘New high performance grouts with high volume stability and good fluidity were prepared with Portland cement and a multifunctional admixture (MFA). The theological characteristics and mechanical performance of the grouts were investigated. The addition of MFA effectively improves the pseudo-plasticity of the grout. The Ma cone flow time decreases obviously, and the bleeding rate tends to be zero. The deformation behaviors of fresh mixture and hardened grout are systematically studied. Mercury injection method (MIP), scanning electron microscopy (SEM) and X-ray diffractory analysis experiments are used to analyze the microstructure evolution of the grouts, which manifests that the co-action of the early bubble reaction and the latter ettringite crystallization ensure the volume stability throughout the whole hydration process and result in refined pore structure of the grout.
基金financially supported by the Project of the Science and Technology Creative Team of Universities in Jiangxi Province,China(No.00008713)the Open Foundation of Jiangxi Key Laboratory for Advanced Copper and Tungsten Materials(No.2013-KLP-04)
基金financially supported by NSAF(No.U1530155)Ministry of Science and Technology(MOST)of China,US–China Collaboration on Cutting-edge Technology Development of Electric Vehicle,the Nation Key Basic Research Program of China(No.2015CB251100)Beijing Key Laboratory of Environmental Science and Engineering(No.20131039031)
基金supported by the Cultivation Project of Major Achievements Transformation of Sichuan Provincial Education Department(#14CZ0005)supported by the Natural Science Foundation of China(#21406184)
基金This work was supported by the National Nat- ural Science Foundation of China under Grant No. 60178021.
文摘In this paper, a depth-graded C/W multilayer mirror with broad grazing incident angular range, consisting of three multilayer stacks, each of which has different period thickness d and the layer pair number, was designed and fabricated by direct current (DC) magnetron sputtering. For calculating the definite performance of such a mirror, the saturation effects of the interfacial imperfection, such as interface roughness and diffusion, were emerged. The reflectivity of the mirror was measured by the X-ray diffraction (XRD) instrument at Cu Kα radiation (λ = 0.154 nm), the measured reflectivity was about 30% in a broad grazing incident angular range (0.55°-0.85°). By the fitting data, the thickness of each layer is almost same as the one designed and the roughness in the multilayer is about 0.85 nm, which is larger than the prospective value of 0.5 nm.
基金supported by Unité de Catalyse et Chimie du Solide (UCCS)sponsor of scholarship: China scholarship council and School of Environment, Tsinghua University
文摘A series of Mo/Si multilayers with the same periodic length and different periodic number were prepared by magnetron sputtering, whose top layers were respectively Mo layer and Si layer. Periodic length and interface roughness of Mo/Si multilayers were determined by small angle X-ray diffraction （SAXRD）. Surface roughness change curve of Mo/Si multilayer with increasing layer number was studied by atomic force microscope （AFM）. Soft X-ray reflectivity of Mo/Si multilayers was measured in National Synchrotron Radiation Laboratory （NSRL）. Theoretical and experimental results show that the soft X-ray reflectivity of Mo/Si multilayer is mainly determined by periodic number and interface roughness, surface roughness has little effect on reflectivity.
基金financially supported by the High-Tech Research and Development Program of China(No.SS2013AA031305)the Key Technologies R&D Program of Tianjin(No.12ZCDGGX49100)
基金This work was supported by the National Natural Sci- ence Foundation of China (No. 10435050, 60378021)by the Nanometer Technology Special Founda- tion of Shanghai Science and Technology Commit- tee (No. 0352nm090).
文摘Ultra-short-period W/C multilayers having periodic thickness range of 1.15-3.01 nm have been fabricated for soft X-ray optics using the high vacuum direct current (DC) magnetron sputtering system. These multilayers were characterized by low-angle X-ray diffraction (LAXRD) and transmission electron microscope (TEM). The results show that the multilayer thin films with periodic thickness more than 1.5 nm have clear W-C interface and low roughness. But the structure of the periodic thickness below 1.5 nm is not clear. Finally, three ways to improve the performance of the multilayers are suggested.
基金supported by the Sino-German Center for Research Promotion (No.GZ 983)the German Science Foundation DFG (No.IRTG 2101)+1 种基金the Joint Fund of the National Natural Science Foundation of Chinathe China Academy of Engineering Physics (No.U1230104)
文摘Near-field holography（NFH）, with its virtues of precise critical dimensions and high throughput, has a great potential for the realization of soft x-ray diffraction gratings. We show that NFH with reflections reduced by the integration of antireflective coatings（ARCs） simplifies the NFH process relative to that of setups using refractive index liquids. Based on the proposed NFH with ARCs, gold-coated laminar gratings were fabricated using NFH and subsequent ion beam etching. The efficiency angular spectrum shows that the stray light of the gratings is reduced one level of magnitude by the suppression of interface reflections during NFH.
基金supported by the Special Foundation for High-level Radioactive Waste Disposal(2007-840,2012-851)the National Natural Science Foundation of China(U1530112,11475008,11075006,91026010)
基金the National Natural Science Foundation of China under Grant No.50672108 and 60644002.
文摘BiOx films are prepared by reactive direct current （DC） magnetron sputtering from a metallic bismuth target in Ar ＋O2 with different O2/Ar ratios. It is found that the optical property of BiOx films is sensitive to O2/Ar ratios and the films deposited at O2/Ar ratio of 0.5 have the best reflectivity contrast under the same conditions. The structure and optical characteristics of the films are studied by X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and spectrophotometer. As revealed by investigations, the phase transition is mainly responsible for the change of optical properties. The static test results indicate that the BiO~ films have good writing sensitivity for blue laser beams. A high reflectivity contrast of about 52% at a writing power of 11 mW and writing pulse width of 800 ns is obtained. In addition, the films demonstrate good stability after being read for 10000 times.
基金This work was supported by the National Basic Research Program of China(No.2003CB314901)the Program for New Century Excellent Talents in University(No.NCET-05-0111)the National Natural Science Foundation of China(No.60576018).
文摘Using two-step method InP epilayers were grown on GaAs（100） substrates by low-pressure metalorganic chemical vapor deposition （LP-MOCVD）. X-ray diffraction （XRD） and room-temperature （RT） photolu- minescence （PL） were employed to characterize the quality of InP epilayer. The best scheme of growing InP/GaAs（100） heterostructures was obtained by optimizing the initial low-temperature （LT） InP growth conditions, investigating the effects of thermal cycle annealing （TCA） and strained layer superlattice （SLS） on InP epilayers. Compared with annealing, 10-periods Ga0.1In0.9P/InP SLS inserted into InP epilayers can improve the quality of epilayers dramatically, by this means, for 2.6-#m-thick heteroepitaxial InP, the full-widths at half-maximum （FWHMs） of XRD ω and ω-28 scans are 219 and 203 arcsec, respectively, the RT PL spectrum shows the band edge transition of InP, the FWHM is 42 meV. In addition, the successful growth of InP/In0.53Ga0.47As MQWs on GaAs（100） substrates indicates the quality of device demand of InP/GaAs heterostructures.
基金supported by the National Natural Science Foundation of China(Nos.6127411311204212 and 61404091)+5 种基金the Program for New Century Excellent Talents in University(No.NCET-11-1064)the Tianjin Natural Science Foundation(Nos.13JCYBJC1570013JCZDJC2610014JCZDJC31500 and 14JCQNJC00800)the Tianjin Science and Technology Developmental Funds of Universities and Colleges(Nos.2010070320130701 and 20130702)
文摘Indium oxide(In_2O_3) films were prepared on Al_2O_3(0001) substrates at 700 °C by metal-organic chemical vapor deposition(MOCVD).Then the samples were annealed at 800 °C,900 °C and 1 000 °C,respectively.The X-ray diffraction(XRD) analysis reveals that the samples were polycrystalline films before and after annealing treatment.Triangle or quadrangle grains can be observed,and the corner angle of the grains becomes smooth after annealing.The highest Hall mobility is obtained for the sample annealed at 900 °C with the value about 24.74 cm^2·V^(-1)·s^(-1).The average transmittance for the films in the visible range is over 90%.The optical band gaps of the samples are about 3.73 e V,3.71 e V,3.70 eV and 3.69 eV corresponding to the In_2O_3 films deposited at 700 °C and annealed at 800 °C,900 °C and 1 000 °C,respectively.
文摘A series of thin Ag films with different thicknesses grown under identical conditions are analyzed by means of spectrophotometer. From these measurements the values of refractive index and extinction coefficient are calculated. The films are deposited onto BK7 glass substrates by direct current （DC） magnetron sputtering. It is found that the optical properties of the Ag films can be affected by films thickness. Below critical thickness of 17 nm, which is the thickness at which Ag films form continuous films, the optical properties and constants vary significantly with thickness increasing and then tend to a stable value up to about 40 nm. At the same time, X-ray diffraction measurement is carried out to examine the microstructure evolution of Ag films as a function of films thickness. The relation between optical properties and microstructure is discussed.
基金This work was supported by the National NaturalScience Foundation of China (No. 60178024) and theCultivation Fund of the Key Scientific and TechnicalInnovation Project, Ministry of Education of China (No.704012)
文摘Different up-conversion luminescent spectra of Er^3＋ ions were observed in the oxyfluoride glass-ceramics. The ratio of two fluorides in the original compositions was modified in order to form different nanocrystals. The intensity of up-conversion luminescence increased sharply when the ratio of PbF2 and CdF2 was 40：10. The data of differential thermal analysis and X-ray diffraction were used to explain the optimization fluoride ratio. The intensity of up-conversion luminescence is not only decided by the crystallizability but also mainly related with the stoiehiometric proportion of fluoride nanocrystals in the glass-ceramics.
