The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particle...The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particles was smiliar to that of kaolinite clay. On the surface of BS, both toluene insoluble organic matter and structural OH group are detected at the same time. The surface characteristics imparted a bi-wettable nature to the BS. As a result, the BS is able to stabilize fine water emulsion in the bitumen phase. The organic matter associated with BS is a possible factor of the fouling on catalyst and equipment.展开更多
A solid state synthesis of ultrafine/nanocrystalline WC-10Co composite powders was reported from WO3 , Co3O4 and carbon powders after reduction and carburization at relatively low temperatures in a short time under pu...A solid state synthesis of ultrafine/nanocrystalline WC-10Co composite powders was reported from WO3 , Co3O4 and carbon powders after reduction and carburization at relatively low temperatures in a short time under pure H2 atmosphere. The effects of ball milling time and reaction temperature on the preparation of ultrafine/nanocrystalline WC-Co composite powders were studied using X-ray diffraction and scanning electron microscope (SEM). The results show that fine mixed oxide powders (WO3 , Co3O4 and carbon powders) can be obtained by long time ball milling. Increasing the reaction temperature can decrease the formation of Co3W3C and graphite phases and increase the WC crystallite size. Long-time ball milling and high reaction temperature are favorable to obtain fine and pure composite powders consisting of nanocrystalline WC from WO3 , Co3O4 and carbon powders.展开更多
The auto-evolved ultrafine copper powders were synlhesized via a novel electrodeposition route performed by ultrasonic dispersion of the electrolyte. The properties of the samples obtained were characterized by X-ray ...The auto-evolved ultrafine copper powders were synlhesized via a novel electrodeposition route performed by ultrasonic dispersion of the electrolyte. The properties of the samples obtained were characterized by X-ray powder diffractometry （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM） and laser size distribution analyzer （SL） respectively. The formation mechanisms of the powders and the efficiency of the elctrodeposition were discussed. The results show that the as-prepared powders are high-purity copper nanoparticles with the fcc structure taking a mixture of fishbone-like and irregular shapes When the concentration of Cu^2＋ increases from 0.03 to 0.09 mol/L, the average size of copper particles increases from 0.92 to 1.80 μm, and current efficiency of electrodeposition linearly changes from 66.5% to 91.3%.展开更多
基金Financially supported by the Opening Fund of National Key Laboratory of State Heavy Oil University of Petroleum+1 种基金 Beijing (2003-04) and the Scientific Research Foundation (SRF) for the Returned Overseas Chinese Scholars (ROCS) State Education Minis
文摘The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particles was smiliar to that of kaolinite clay. On the surface of BS, both toluene insoluble organic matter and structural OH group are detected at the same time. The surface characteristics imparted a bi-wettable nature to the BS. As a result, the BS is able to stabilize fine water emulsion in the bitumen phase. The organic matter associated with BS is a possible factor of the fouling on catalyst and equipment.
基金Projects(50823006, 51021063, 51271152) supported by the National Natural Science Foundation of ChinaProject(NCET-10-0842)supported by the Program for New Century Excellent Talents in Universities of China
文摘A solid state synthesis of ultrafine/nanocrystalline WC-10Co composite powders was reported from WO3 , Co3O4 and carbon powders after reduction and carburization at relatively low temperatures in a short time under pure H2 atmosphere. The effects of ball milling time and reaction temperature on the preparation of ultrafine/nanocrystalline WC-Co composite powders were studied using X-ray diffraction and scanning electron microscope (SEM). The results show that fine mixed oxide powders (WO3 , Co3O4 and carbon powders) can be obtained by long time ball milling. Increasing the reaction temperature can decrease the formation of Co3W3C and graphite phases and increase the WC crystallite size. Long-time ball milling and high reaction temperature are favorable to obtain fine and pure composite powders consisting of nanocrystalline WC from WO3 , Co3O4 and carbon powders.
基金Project(08JJ3104) support by Hunan Provincial Natural Science Foundation of China
文摘The auto-evolved ultrafine copper powders were synlhesized via a novel electrodeposition route performed by ultrasonic dispersion of the electrolyte. The properties of the samples obtained were characterized by X-ray powder diffractometry （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM） and laser size distribution analyzer （SL） respectively. The formation mechanisms of the powders and the efficiency of the elctrodeposition were discussed. The results show that the as-prepared powders are high-purity copper nanoparticles with the fcc structure taking a mixture of fishbone-like and irregular shapes When the concentration of Cu^2＋ increases from 0.03 to 0.09 mol/L, the average size of copper particles increases from 0.92 to 1.80 μm, and current efficiency of electrodeposition linearly changes from 66.5% to 91.3%.
