应用数学

Each optimizing method has its strong point. On the point of view of math, optimizing for motor design is a process for extremum point for a nonlinear, restricted recessive function. Genetic Algorithms G.A.

从数学角度上来说，电机的优化设计就是一组非线性、有约束条件的隐性函数求极值问题，目前比较成熟的优化方法主要有遗传算法、模拟退火法与Tabu法等，其中以遗传算法应用最为广泛。

This article introduces three kinds of signal channel and gives some simulation results based on Rayleigh channel.

文中所有信号的仿真结果都是在Rayleigh信道下得到的。通过对MIMO传输矩阵的数学变换，我们可以得到一种比较简单的一对一的传输系统，这对理解MIMO的传输原理以及传输系统的仿真应用都有比较好的实用价值。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。