熱導率








热导率k{displaystyle k}k是指材料直接传导热能的能力，或称热传导率。热导率定义为单位截面、长度的材料在单位温差下和单位时间内直接传导的熱能。热导率的单位为瓦米-1开尔文-1W mK{displaystyle W over mK}{W over mK}。


热导率k=ΔQAΔtxΔT{displaystyle k={frac {Delta Q}{ADelta t}}{frac {x}{Delta T}}}k={frac {Delta Q}{ADelta t}}{frac {x}{Delta T}} ,其中A{displaystyle A}A是导热体的横截面积，ΔQΔt{displaystyle {frac {Delta Q}{Delta t}}}{frac {Delta Q}{Delta t}}是单位时间内传导的热能，x{displaystyle x}x是两热源间导热体的厚度，ΔT{displaystyle {Delta T}}{Delta T}则是温度差。



物質的熱導率


















































































































物質
物質狀態
 導熱率Wm-1K-1
石墨烯 固態 (4840±440) ~ (5300±480)
金刚石 固態 900 ~ 2320
銀 固態 420
銅 固態 401
黃金 固態 318
鋁 固態 237
白金 固態 70
鐵 固態 80
鋼 固態 60
鉛 固態 35
汞 液態 8.34
冰 固態 2
陶瓷 固態 1.22
玻璃 固態 1.1
水 液態 0.6
聚乙烯 固態 0.3
尼龍 固態 0.2
石蠟油 液態 0.2
石棉 固態 0.2
聚苯乙烯 固態 0.033
軟木塞 固態 0.50
採用在標準狀況下的數據。對於氣體，值是對應於cp。


相關條目


  • 热传导



-

Popular posts from this blog

Guess what letter conforming each word

Image
6 $begingroup$ This is an entry in the Fortnightly Topic Challenge #41: Short and Sweet. 1 letter only could be mean anything . With an additional letter in front , could be used as medicine component and something you definitely learn or at least heard once. Add another letter in front , you would possibly hear that many times . Add an additional letter in front , you would found an independent country . With an additional letter, in the end , you would found something related to apple . Add another letter in the end , you would found something bad . Hint: Each letter is unique . word knowledge letters chemistry share | improve this question ...
Read more

Port of Spain

Image
For ports in the country of Spain, see List of ports in Spain. City in City of Port of Spain, Trinidad and Tobago Port of Spain City City of Port of Spain Top to bottom (left to right): Skyline of Port of Spain from Gulf of Paria; National Academy for the Performing Arts, Independence Square, Eric Williams Plaza; MovieTowne, Port of Port of Spain Motto(s):  "We Gather Strength As We Go Along" Port of Spain Coordinates: 10°40′N 61°31′W  /  10.667°N 61.517°W  / 10.667; -61.517 Coordinates: 10°40′N 61°31′W  /  10.667°N 61.517°W  / 10.667; -61.517 Country   Trinidad and Tobago Jurisdiction City of Port of Spain Settled 1560 Incorporated (town) 1853 Incorporated (city) 1914 Government  • Mayor Joel Martinez  • Governing body City Corporation Area [1]  • City 12 km 2 (5 sq mi) Elevation [2] 66 m (217 ft) Population (2011) [1]  • City 37,074  • Rank 3rd  • Density 3,090/km 2 (8,000/sq mi)...
Read more

Run scheduled task as local user group (not BUILTIN)

Image
0 I am trying to run a scheduled task with User Group (not a single user). This is working fine when I in the field "when running a task, use the following user account:" insert BUILTIN User Group (for example: Administrators or Users). But when I try it with the created Local User Group (example: TestGroup) it is not working. The Users in the TestGroup are the same as in the Administrators group. What could be the problem? Are there some restrictions to the Created User Group compared to BUILTINUsers? scheduled-tasks taskscheduler windowstaskschedule share | improve this question asked Nov 15 '18 at 15:36 Far...
Read more