Porous medium has an obvious effect on the formation of carbon dioxide hydrate. In order to study the characteristics of CO2 hydrate formation in porous medium below the freezing point, the experiment of CO2 hydrate f...Porous medium has an obvious effect on the formation of carbon dioxide hydrate. In order to study the characteristics of CO2 hydrate formation in porous medium below the freezing point, the experiment of CO2 hydrate formation was conducted in a high-pressure 1.8-L cell in the presence of porous media with a particle size of 380 μm, 500 μm and 700 μm, respectively. The test results showed that the porous medium had an important influence on the process of CO2 hydrate formation below the freezing point. Compared with porous media with a particle size of 500 μm and 700 μm, respectively, the average hydrate formation rate and gas storage capacity of carbon dioxide hydrate in the porous medium with a particle size of 380 μm attained 0.016 14 mol/h and 65.094 L/L, respectively. The results also indicated that, within a certain range of particle sizes, the smaller the particle size of porous medium was, the larger the average hydrate formation rate and the gas storage capacity of CO2 hydrate during the process of hydrate formation would be.展开更多
Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated....Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated. The reflect loss was less than -20 dB for all of the composites in different frequency ranges. The cube-like and walnut-like Fe3O4 composites exhibit improved complex permittivity and permeability and dual-frequency and wide bandwidth absorption characteristics, which is mainly attributed to the larger shape anisotropy. Such a high absorption property indicates that these porous Fe3O4 particles with various morphologies are very promising for electromagnetic wave absorptive materials.展开更多
基金financially supported by the Natural Science Foundation of China (No. 51266005)the Science and Technology Research Key Project of the Ministry of Education (No. 1106ZBB007)+1 种基金the Hongliu Outstanding Talent Program of LUT (No. Q201101)the Open Fund of Natural Gas Hydrate Key Laboratory, Chinese Academy of Sciences (No. y007s3)
文摘Porous medium has an obvious effect on the formation of carbon dioxide hydrate. In order to study the characteristics of CO2 hydrate formation in porous medium below the freezing point, the experiment of CO2 hydrate formation was conducted in a high-pressure 1.8-L cell in the presence of porous media with a particle size of 380 μm, 500 μm and 700 μm, respectively. The test results showed that the porous medium had an important influence on the process of CO2 hydrate formation below the freezing point. Compared with porous media with a particle size of 500 μm and 700 μm, respectively, the average hydrate formation rate and gas storage capacity of carbon dioxide hydrate in the porous medium with a particle size of 380 μm attained 0.016 14 mol/h and 65.094 L/L, respectively. The results also indicated that, within a certain range of particle sizes, the smaller the particle size of porous medium was, the larger the average hydrate formation rate and the gas storage capacity of CO2 hydrate during the process of hydrate formation would be.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51072038, 50772025 and 21001035)NECT, Outstanding Youth Foundation of Heilongjiang Province (Grant No. JC201008)+4 种基金the Natural Science Foundation of Heilongjiang Province, China (Grant No. F200828)the Ministry of Science and Technology of China (Grant No. 2008DFR20420)the Fundamental Research Funds for the Central Universities (Grant Nos. HEUCFT1010, HEUCF101016, HEUCF20111124 and HEUCF101016)the National Basic Research Program of China (Grant No. 2007CB310500)Harbin Key Sci-Tech Project (Grant No. 2010AA4BG004)
文摘Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated. The reflect loss was less than -20 dB for all of the composites in different frequency ranges. The cube-like and walnut-like Fe3O4 composites exhibit improved complex permittivity and permeability and dual-frequency and wide bandwidth absorption characteristics, which is mainly attributed to the larger shape anisotropy. Such a high absorption property indicates that these porous Fe3O4 particles with various morphologies are very promising for electromagnetic wave absorptive materials.
