【多选题】关于导热系数,下列说法正确的是?
A.
同一种材料,在任何情况下都具有相同的导热系数
【简答题】In 2012, I had just recovered form a serious illness when I received an invitation to a writer's conference in Orlando, Florida. My family persuaded me that a(n) might be just what the doctor ordered,...
【简答题】i + i 2 + i 3 +……+ i 2012 = .
【单选题】复数 i 2012 i 2011 +2 的虚部为( )
【简答题】In December 2012.my parents asked me what I wanted for Christmas. I told them I would get back t0 them once I thought of . At chat point .I had tie full of asking for something . but for the first tim...
【单选题】不同的材料其导热系数不同,下列关于导热系数的叙述不正确的是( )。
A.
导热系数值以金属于最大,非金属于次之,而气体最小
C.
多孔绝热材料由于孔隙率高,气体对导热系数起主要作用,而固体部分有结构对其影响不大。
D.
在材料孔隙率相同的条件下,孔隙尺寸愈大,导热系数越大。
【简答题】计算:i﹣i 2 +i 3 ﹣i 4 +…+(﹣1) 2011 i 2012 =( )(i表示虚数单位).
【单选题】In 2012, I had just recovered from a serious illness when I received an invitation to a writers conference in Orlando, Florid A. My family persuaded me that a(n)【C1】______might be just what the doctor...
【单选题】如图给出的是计算 1 2 + 1 4 + 1 6 +…+ 1 2012 的值的程序框图,其中判断框内应填入的是( )
【简答题】(1)试求i 1 ,i 2 ,i 3 ,i 4 ,i 5 ,i 6 ,i 7 ,i 8 的值; (2)由(1)推测i n (n∈N * )的值有什么规律,并用式子表示出来. (3)计算:i 2012 的值.