null

• The null subset corresponds to the term 1 .
  空集则对应于常数项1。
• The operator o is the null operator .
  算符O是零算符。
• A promise obtained by force is legally null .
  一个以武力获得的契约在法律上是无效的。
• This check is null and void .
  本支票无效。
• He was null .
  他是一个毫不引人注意的人。
• The null result was directly related to a central postulate of the theory .
  零结果都直接与理论的中心假设相联系。
• The device provides extreme sensitivity through a small range around the null point .
  此装置在零点附近很小一段范围内具有极高的灵敏度。
• The zero or null matrix denoted by 0 is definde as a matrix all of whose elements are zero .
  如果一个矩阵的所有元素都为零，则称它为零矩阵。
• A null output should occur when the core is at the center point between the two secondary coils .
  当磁心位于两个次级线圈之间的中点时，没有输出。
• As a result, the denominator and numerator should be about equal if the null hypothesis is true .
  因此，如果无效假设为真，那么分母和分子应该差不多相等。