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在《通用技术》课程教学中“结构的强度与材料的形状有关”的小实验
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作者 熊继承 《中国校外教育(上旬)》 2017年第11期112-113,共2页
结构的强度是通过构件和材料来体现的。构件在外力作用下会变形,同时,构件内部各质点之间的相互作用力发生了改变,这种改变的力为内力。外力越大,则构件的内力越大,当内力达到一定数值时,构件就会被破坏。在工程技术中不允许任何构件在... 结构的强度是通过构件和材料来体现的。构件在外力作用下会变形,同时,构件内部各质点之间的相互作用力发生了改变,这种改变的力为内力。外力越大,则构件的内力越大,当内力达到一定数值时,构件就会被破坏。在工程技术中不允许任何构件在正常情况下被破坏,这就要求构件和材料必须具有抵抗破坏的能力,这种能力就是强度。同时,在外力与材料不变的条件下,构件被破坏的危险程度还与它的横截面积有关。试验在于验证改变材料的形状,增加横截面积,从而增加结构的强度。 展开更多
关键词 结构的强度 材料的形状 横截面积
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Preparation,Characterization and Service Performance of Fatty Acid/PMMA Shape-Stabilized Phase Change Material 被引量:3
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作者 孟多 王立久 《Journal of Donghua University(English Edition)》 EI CAS 2011年第1期10-14,共5页
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
关键词 shape-stabilized phase change material fatty acid poly methyl methacrylate(PMMA) bulk polymerization
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