Microorganism-mediated, hexadecyltrimethylammonium chloride （CTAC）-directed （MCD） method was employed in this work to synthesize Pd nanoflowers （PdNFs）. Proper Pichia postoris cells （PPCs） dosage, ascorbic ac...Microorganism-mediated, hexadecyltrimethylammonium chloride （CTAC）-directed （MCD） method was employed in this work to synthesize Pd nanoflowers （PdNFs）. Proper Pichia postoris cells （PPCs） dosage, ascorbic acid （AA）, Pd（N03）2 and CrAC concentrations were essential for the growth of the PdNFs. The size of the as- synthesized PdNFs could be tuned by adjusting the amount of Pal（N03）2 solution and dosage of PPCs used. Characterization techniques such as X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to verify the nature of the PdNFs. Finally the PdNF/PPC nanocomposites were immobilized onto TiO2 supports to obtain bio-PdNF/Ti02 catalysts which showed excellent catalytic activity for CO oxidation, obtaining 100%; conversion at 100 ℃ and remaining stable over a period of 52 h of reaction time. @ 2015 The Chemical Industry and Engineering Sodety of China, and Chemical Industry Press. All rights reserved.展开更多
A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platfo...A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector. The simulation results show that the conversion efficiency could be more than 65%, if the X-ray beam width is less than about 0.2 mm, and a tungsten slab with 0.2 mm thickness and 30 mm length is employed as a radiation conversion medium. Meanwhile the results indicate that this new detector has higher conversion efficiency as well as less volume. Theoretically this new kind of detector could take place of the traditional scintillation detector for HECT.展开更多
X-ray computer tomography(CT)has been intensively applied to the research of cement-based materials,while most of the CT applications are qualitative.To have more quantitative applications,the arbitrary grayscale valu...X-ray computer tomography(CT)has been intensively applied to the research of cement-based materials,while most of the CT applications are qualitative.To have more quantitative applications,the arbitrary grayscale values and the specially defined CT numbers of the main cement constituents,including the cement clinkers,the hydrated products,and some durability products are calibrated on an industrial CT system in this study.The calibration results can deepen our understandings of the X-ray CT image of the cement-based materials.The universalities of the calibrated results and the calibration procedures are clarified.The potential applications are anticipated,such as segmentation of the individual phases,quantitative durability research,porosity determinations,and quantitative composition characterizations.展开更多
基金Supported by the National Natural Science Foundation of China （21106117, 21036004）.
文摘Microorganism-mediated, hexadecyltrimethylammonium chloride （CTAC）-directed （MCD） method was employed in this work to synthesize Pd nanoflowers （PdNFs）. Proper Pichia postoris cells （PPCs） dosage, ascorbic acid （AA）, Pd（N03）2 and CrAC concentrations were essential for the growth of the PdNFs. The size of the as- synthesized PdNFs could be tuned by adjusting the amount of Pal（N03）2 solution and dosage of PPCs used. Characterization techniques such as X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to verify the nature of the PdNFs. Finally the PdNF/PPC nanocomposites were immobilized onto TiO2 supports to obtain bio-PdNF/Ti02 catalysts which showed excellent catalytic activity for CO oxidation, obtaining 100%; conversion at 100 ℃ and remaining stable over a period of 52 h of reaction time. @ 2015 The Chemical Industry and Engineering Sodety of China, and Chemical Industry Press. All rights reserved.
基金supported by the National Natural Science Foundation of China (No.60672098)the Tackling Key Problems of Science and Technology of ChongQing (No.CSTC2009AC3047)
文摘A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector. The simulation results show that the conversion efficiency could be more than 65%, if the X-ray beam width is less than about 0.2 mm, and a tungsten slab with 0.2 mm thickness and 30 mm length is employed as a radiation conversion medium. Meanwhile the results indicate that this new detector has higher conversion efficiency as well as less volume. Theoretically this new kind of detector could take place of the traditional scintillation detector for HECT.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2242014R30014)State Key Laboratory of High Performance Civil Engineering Materials of China(Grant No.2012CEM008)
文摘X-ray computer tomography(CT)has been intensively applied to the research of cement-based materials,while most of the CT applications are qualitative.To have more quantitative applications,the arbitrary grayscale values and the specially defined CT numbers of the main cement constituents,including the cement clinkers,the hydrated products,and some durability products are calibrated on an industrial CT system in this study.The calibration results can deepen our understandings of the X-ray CT image of the cement-based materials.The universalities of the calibrated results and the calibration procedures are clarified.The potential applications are anticipated,such as segmentation of the individual phases,quantitative durability research,porosity determinations,and quantitative composition characterizations.
