Oxide-reduced copper powder can be produced efficiently at low cost. The volume shrinkage, porosity, maximum pore size, permeability and thermal conductivity of wicks sintered from two oxide-reduced （OR） powders wer...Oxide-reduced copper powder can be produced efficiently at low cost. The volume shrinkage, porosity, maximum pore size, permeability and thermal conductivity of wicks sintered from two oxide-reduced （OR） powders were compared with one from water-atomized （WA） powder. The green specimens were sintered at temperatures from 800 to 1000 ℃ in a tube furnace under a reduction stream of 10% hydrogen and 90% argon. The results show that the property variations of OR - 100 and WA wicks due to porosity changes have a similar tendency and range. Nine hundred degree celsius is a recommended sintering temperature for producing ideal wicks for use in heat pipes. A smaller maximum pore size can be obtained by increasing the green density.2007 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.展开更多
In this paper, the dielectric properties of CO2, CO2/air, CO2/O2, CO2/N2, CO2/CF4, CO2/CH4, CO2/He, C02/H2, CO2/NH3 and CO2/CO were investigated based on the Boltzmann equation analysis, in which the reduced critical ...In this paper, the dielectric properties of CO2, CO2/air, CO2/O2, CO2/N2, CO2/CF4, CO2/CH4, CO2/He, C02/H2, CO2/NH3 and CO2/CO were investigated based on the Boltzmann equation analysis, in which the reduced critical electric field strength （E/N）cr of the gases was derived from the calculated electron energy distribution function （EEDF） by solv- ing the Boltzmann transport equation. In this work, it should be noted that the fundamental data were carefully selected by the published experimental results and calculations to ensure the validity of the calculation. The results indicate that if He, H2, N2 and CH4, in which there axe high ionization coefficients or a lack of attachment reactions, are added into CO2, the dielectric properties will decrease. On the other hand, air, O2, NH3 and CFa （ranked in terms of （E/N）cr value in increasing order） have the potential to improve the dielectric property of CO2 at room temperature.展开更多
The relationship between the reduced viscosity and concentation of sulfonated styrene-isoprene- styrene triblock copolymer（SSIS） and its ionomers in toluene and toluene/methanol solutions were studied. The intrinsic...The relationship between the reduced viscosity and concentation of sulfonated styrene-isoprene- styrene triblock copolymer（SSIS） and its ionomers in toluene and toluene/methanol solutions were studied. The intrinsic viscosity \ was calculated. The results show that SSIS tends to form an intra-molecular chain interaction and form more enclosed molecular chain with a lower reduced viscosity and intrinsic viscosity when the sulfonation degree x（SO3H） decreased. A change of interaction from intra- to inter-molecular chain was observed, and the intrinsic viscosity improved from 0.641 dL/g to 0.656 dL/g by increasing the sulfonation degree from 3.95% to 7.36% due to the chain combination. This also make the size of molecular chain of SSIS larger than SIS . Although be a precipitant for SIS , a few amounts of methanol can change the solubility of SSIS in toluene by destroying the combination of molecular chain. Lanthanum ionomers showed a lower reduced viscosity as compared with sodium and zinc ionomers.展开更多
文摘Oxide-reduced copper powder can be produced efficiently at low cost. The volume shrinkage, porosity, maximum pore size, permeability and thermal conductivity of wicks sintered from two oxide-reduced （OR） powders were compared with one from water-atomized （WA） powder. The green specimens were sintered at temperatures from 800 to 1000 ℃ in a tube furnace under a reduction stream of 10% hydrogen and 90% argon. The results show that the property variations of OR - 100 and WA wicks due to porosity changes have a similar tendency and range. Nine hundred degree celsius is a recommended sintering temperature for producing ideal wicks for use in heat pipes. A smaller maximum pore size can be obtained by increasing the green density.2007 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.
基金supported in part by the National Key Basic Research Program of China(973 Program)(No.2015CB251002)the Science and Technology Project Funds of the Grid State Corporation of China(No.SGSNK00KJJS1501564)+2 种基金National Natural Science Foundation of China(Nos.51221005,51577145)the Fundamental Research Funds for the Central Universities of Chinathe Program for New Century Excellent Talents in University,China
文摘In this paper, the dielectric properties of CO2, CO2/air, CO2/O2, CO2/N2, CO2/CF4, CO2/CH4, CO2/He, C02/H2, CO2/NH3 and CO2/CO were investigated based on the Boltzmann equation analysis, in which the reduced critical electric field strength （E/N）cr of the gases was derived from the calculated electron energy distribution function （EEDF） by solv- ing the Boltzmann transport equation. In this work, it should be noted that the fundamental data were carefully selected by the published experimental results and calculations to ensure the validity of the calculation. The results indicate that if He, H2, N2 and CH4, in which there axe high ionization coefficients or a lack of attachment reactions, are added into CO2, the dielectric properties will decrease. On the other hand, air, O2, NH3 and CFa （ranked in terms of （E/N）cr value in increasing order） have the potential to improve the dielectric property of CO2 at room temperature.
文摘The relationship between the reduced viscosity and concentation of sulfonated styrene-isoprene- styrene triblock copolymer（SSIS） and its ionomers in toluene and toluene/methanol solutions were studied. The intrinsic viscosity \ was calculated. The results show that SSIS tends to form an intra-molecular chain interaction and form more enclosed molecular chain with a lower reduced viscosity and intrinsic viscosity when the sulfonation degree x（SO3H） decreased. A change of interaction from intra- to inter-molecular chain was observed, and the intrinsic viscosity improved from 0.641 dL/g to 0.656 dL/g by increasing the sulfonation degree from 3.95% to 7.36% due to the chain combination. This also make the size of molecular chain of SSIS larger than SIS . Although be a precipitant for SIS , a few amounts of methanol can change the solubility of SSIS in toluene by destroying the combination of molecular chain. Lanthanum ionomers showed a lower reduced viscosity as compared with sodium and zinc ionomers.
