Crofton's Method Let X1 and X2 be independent random variables that are uniformly distributed over the interval [o, a]. We are interested in computing E[ -X2l]. For instance, in an urban setting, X1 and X2 may denote the location of an accident and the location where an emergency vehicle is currently parked in a road segment of length a, respectively In this case, we want to know the distance
用X射线衍射及氧含量分析法测定了Sm1+xBa2-xCu3Oy固溶区域为0 ≤ x ≤ 0.4。当x<0.25时,Sm1+xBa2-xCu3Oy属正交晶系;x=0.25时,发生从正交到四方的相变;在整个固溶区域内,Tc随x的增加而下降,直至淬灭。同时探讨了Sm1+xBa2-xCu3Oy化合物在不同的淬火温度、氧含量与晶体结构、超导电性的关系