A series of fatty acid/poly methyl methacrylate(PMMA) shape-stabilized phase change materials(PCMs) have been prepared by bulk polymerization method.In the composite,fatty acid(capric acid,stearic acid,and their eutec...A series of fatty acid/poly methyl methacrylate(PMMA) shape-stabilized phase change materials(PCMs) have been prepared by bulk polymerization method.In the composite,fatty acid(capric acid,stearic acid,and their eutectic mixture) acts as core material and PMMA serves as matrix,which coats the fatty acid to prevent the leakage of melted fatty acid.The prepared shape-stabilized PCMs were characterized on the morphology,phase change behavior,chemical characterization and thermal properties.The results indicate that the composites with proper phase change temperature and latent heat are able to keep solid morphology in macro level during thermal storage process.Thermal cycling test also indicates that the composite PCMs have good thermal reliability.Moreover,thermal conductivity and thermal performance are investigated and the results show that the shape-stabilized PCMs have the higher thermal conductivity than fatty acid and exhibited good thermal performance in controlling the atmosphere temperature.展开更多
The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power ...The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.展开更多
The polymorphic phase transformation of β-glycine to α-glycine was carried out both in the absence and presence of various concentrations of oleic acid used as additive at 25 ℃ in a water/ethanol medium. The effect...The polymorphic phase transformation of β-glycine to α-glycine was carried out both in the absence and presence of various concentrations of oleic acid used as additive at 25 ℃ in a water/ethanol medium. The effects of oleic acid and its concentration on phase transformation time were determined by continuously measuring the ultrasonic velocity. The crystals obtained by the completion of the phase transformation were characterized by XRD, SEM, and TG/DTG. The XRD and SEM results indicated that oleic acid significantly impacted phase transformation time and the morphological characteristics of the crystals. In addition to SEM analysis, detailed crystal shape analysis was performed and the circularity, elongation, and convexity parameters were determined quantitatively. TG/DTG analyses were performed to investigate thermal decomposition behavior and to calculate the activation energies based on different kinetic models such as FWO, KAS, Starink, and Tang kinetic models. With the addition of oleic acid to the medium, the calculated activation energy values increased from 89.63–90.63 to153.8–155.4 kJ·mol^（-1）. The activation energy values showed that oleic acid was adsorbed on the crystal surface;this result was supported by FTIR, elemental, and Kjeldahl analyses.展开更多
基金Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period (No.2006BAJ04A04)Liaoning Scientific Research Program of Colleges and Universities,China (No. 2008S190)
文摘A series of fatty acid/poly methyl methacrylate(PMMA) shape-stabilized phase change materials(PCMs) have been prepared by bulk polymerization method.In the composite,fatty acid(capric acid,stearic acid,and their eutectic mixture) acts as core material and PMMA serves as matrix,which coats the fatty acid to prevent the leakage of melted fatty acid.The prepared shape-stabilized PCMs were characterized on the morphology,phase change behavior,chemical characterization and thermal properties.The results indicate that the composites with proper phase change temperature and latent heat are able to keep solid morphology in macro level during thermal storage process.Thermal cycling test also indicates that the composite PCMs have good thermal reliability.Moreover,thermal conductivity and thermal performance are investigated and the results show that the shape-stabilized PCMs have the higher thermal conductivity than fatty acid and exhibited good thermal performance in controlling the atmosphere temperature.
基金Supported by the National Key Technology Research and Development Program of China(Nos.2012BAD25B08,2012BAD25B00)
文摘The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.
基金Supported by Marmara University Scientific Research Projects Commission under the funding FEN-C-DRP-131216-0547
文摘The polymorphic phase transformation of β-glycine to α-glycine was carried out both in the absence and presence of various concentrations of oleic acid used as additive at 25 ℃ in a water/ethanol medium. The effects of oleic acid and its concentration on phase transformation time were determined by continuously measuring the ultrasonic velocity. The crystals obtained by the completion of the phase transformation were characterized by XRD, SEM, and TG/DTG. The XRD and SEM results indicated that oleic acid significantly impacted phase transformation time and the morphological characteristics of the crystals. In addition to SEM analysis, detailed crystal shape analysis was performed and the circularity, elongation, and convexity parameters were determined quantitatively. TG/DTG analyses were performed to investigate thermal decomposition behavior and to calculate the activation energies based on different kinetic models such as FWO, KAS, Starink, and Tang kinetic models. With the addition of oleic acid to the medium, the calculated activation energy values increased from 89.63–90.63 to153.8–155.4 kJ·mol^（-1）. The activation energy values showed that oleic acid was adsorbed on the crystal surface;this result was supported by FTIR, elemental, and Kjeldahl analyses.
