热力学 |
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热胀冷缩是指物体受热时会膨胀,遇冷时会收缩的特性。由于物体内的粒子(原子)运动会随温度改变,当温度上升时,粒子的振动幅度加大,令物体膨胀;但当温度下降时,粒子的振动幅度便会减少,使物体收缩。
热胀冷缩是一般物体的特性,4度以下的水、锑、铋、镓和青铜等物质,在某些温度范围内受热时收缩,遇冷时会膨胀,恰与一般物体特性相反。因此,水结冰时,冰是先在水面出现。由于铁轨有热胀冷缩的特性,因此铁轨连结时须保持一定距离,避免轨道间互相挤压导致变形。
参考文献
外部链接
- Glass Thermal Expansion Thermal expansion measurement, definitions, thermal expansion calculation from the glass composition
- Water thermal expansion calculator
- DoITPoMS Teaching and Learning Package on Thermal Expansion and the Bi-material Strip
- Engineering Toolbox – List of coefficients of Linear Expansion for some common materials
- Article on how αV is determined
- MatWeb: Free database of engineering properties for over 79,000 materials
- USA NIST Website – Temperature and Dimensional Measurement workshop
- Hyperphysics: Thermal expansion
- Understanding Thermal Expansion in Ceramic Glazes