角的正切

In order to raise the accuracy of the measurement of tangent of dielectric loss angle in XLPE cables,efforts were made to explore the effect of sample preparation and use of protective ring,i.e.the effect of different protective rings and different distance between the protective ring and the insulation shield on the accuracy of the tgδ measurement under a given measuring voltage.

为了提高交联聚乙烯绝缘电力电缆介质损耗角正切测量的准确性，对电缆试样制作保护环等问题进行了深入地探讨，即在一定的测量电压下，采用不同的保护环以及保护环与绝缘屏蔽之间不同的距离，对tgδ测量值的影响进行了探讨，并对测量工作提出了应注意的若干问题。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。