LED芯片一般采用蓝宝石(Al2O3)、硅()、碳化硅()等半导体材料,其中SiC可作为V型接触的芯片衬底。 ()
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三基色荧光粉()转换LED的优点是A
A. 易于获得颜色一致的白光,这是因为颜色仅仅由荧光粉配比决定
B. 结构简单,制作工艺相对简单比较成熟,成本较低
C. 荧光粉的稳定度已经可以满足颜色还原度的要求
______ 是一种常见的近场危害源,可形成高压,强电场,瞬时大电流,并伴有强电磁辐射,形成静电放电电磁脉
which statements are correct for EOQ assumption ?
A. demand is constant and fixed.
B. supply lead time is constant and fixed.
C. only inventory carrying cost and order cost are considered.
D. only inventory carrying cost and stock-out cost are considered.
Which activities are inbound logistics activities?
A. customer service B. demand forecasting C. procurement D. supply management
B. demand forecasting
C. procurement D. supply management
D. supply management
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