Both nickel and lead have seen available stocks shrink to critically low levels this year and this means that any possible disruption to supplies has had an amplified effect on prices.
The effect of arch degree, concrete's shrink and creep is distinct.
拱度和混凝土的收缩、徐变的影响比较明显。
3
But checked Chad engineering core column is fixed with aluminum alloy column, so will lose freedom scale effect, when heat bilges cold shrink large internal stress.