哪种晶界能有效阻止滑移并且增加材料强度?
A: small-angle grain boundaries
B: twin boundaries
C: big-angle grain boundaries
D: large grains
A: small-angle grain boundaries
B: twin boundaries
C: big-angle grain boundaries
D: large grains
举一反三
- There should be no national boundaries in _________ protection.
- There should be no national boundaries in _________ protection.
- 点缺陷包含的类型 A: Vacancy B: Interstitial C: Dislocation D: Boundaries
- 点缺陷包含的类型 A: vacancy B: interstitial C: dislocation D: boundaries
- （）is a measure of the market value of all goods and services within the boundaries of a nation.