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In this thesis, three major achievements were made in theoretical study: conditions and rules for preparing nano-powders by chemical precipitation are analyzed from the point of view of thermodynamics and kinetics, the principle, standards and experimental method for the aqueous dispersion of nano-scaled metal oxide powders were proposed and verified, mathematical model of nano-filming addition of dopants by chemical coprecipitation was established. In experimental research, nm-ZnO, nm-Bi〓O〓, nm-Co〓O〓 and nm-MnO powder with spherical shape, narrow particle size distribution and small particle size were prepared successfully, highly stable and dispersive aqueous suspensoid of nm-ZnO, nm-TiO〓, nm-Co〓O〓 and nm-MnO powder were prepared successfully and surface modification on these nano-powders was also achieved, 0-3 nanocomposite ZnO varistors with nm-ZnO, nm-TiO〓and nm-MnO respectively were prepared successfully by conventional mechanical attrition, and exhibited much better electrical properties than those of conventional varistors.

综上所述，本文在理论研究方面取得了三项成果：（1）从热力学和动力学角度推导并分析了液相化学沉淀法制备纳米粉体的反应条件和规律，（2）提出了纳米氧化物的水分散体系的设计原理、规范和通用实验步骤，（3）提出了共沉淀的数学模型和计算方法；在实验方面所取得的成果有：（1）成功制备了粒度小、分布窄、形貌对称的纳米氧化锌、纳米氧化铋、纳米氧化钴和纳米氧化亚锰，（2）成功地制备了纳米氧化锌、纳米二氧化钛、纳米氧化钴和纳米氧化锰的高稳定分散悬浮液并实现了干粉体的表面改性，（3）成功地进行了纳米氧化锌、纳米二氧化钛和纳米氧化锰对压敏电阻的0—3复合掺杂实验，试样性能远优于常规压敏电阻，为实现压敏电阻的高能高压化提供了新的方法和思路。

In this paper, the mathematical model of the three-level STATCOM based on the switching function is presented.

利用开关函数的概念，建立了三电平STATCOM的数学模型。

Secondly, establish the mathematical model of matrix converter based on the switching function; also SPWM feedforward compensation were studied.

其次，建立了基于开关函数的矩阵式变换器的数学模型；另外还对SPWM前馈补偿技术进行了研究。

There are several methods can be applied in symptom complex study: Principal component analysis, Factor analysis, Cluster analysis, Regression analysis, and Correspondence analysis, etc. In this article, the author introduces the application of multivariate statistical analysis in TCM symptom complex normalization research in the following four aspects: establishing the basic symptom, filtering optimization index, settling the weight of the index, and setting up the mathematical model.

本文从确立基本证型、筛选优化指标、确立优化指标的权重、建立证候数学模型等4个环节上介绍了多元统计分析在中医证候诊断标准领域的应用，并指出：多元统计分析是研究多因素和多指标问题的统计分析方法，证候诊断学正是研究疾病的多种证型与多种症状之间的关系问题，因此，可以将多元统计分析应用于中医证候的规范化研究中。

To understand this paradox, we have formulated a mathematical model of activity-mediated synapse elimination.

为了了解这种矛盾情况，我们建立了一个活动介导突触排除模型的数学模型。

This paper analyzes the characteristic and variables of the ordnance supply system, gives the flow chart of the system, sets up the mathematical model of the system in system dynamics and gives an example.

本文分析了军械供应系统的特点、各类变量并进行了系统的结构分析，给出了系统的流图，运用系统动力学建立了军械供应系统的模型，最后进行了举例分析，目的在于为进一步研究提供基础。

In this paper, the mathematical model of DFIG and variable pitch system is established.

本文分别分析了双馈发电机和变桨距系统的数学模型。

The construction of the mathematical model of the variable valve system and its dynamic analysis are also presented.

本文也对此系统的学模型作出推导，并进动态分析。

On the basis of the mathematical model, the dynamic derivative of the aircraft at the different angles of the tailplane was analyzed using the technique of dynamic derivative simulation.

在非定常建模的基础上，采用动导数仿真，分析了不同平尾偏角时的动导数，结果表明，水平尾翼偏角主要对零动态阻尼所对应迎角有较大影响，随着舵偏角的增大，该迎角减小。

Mainly, the paper has introduced the mathematical model of the take-up process.

主要介绍卷绕过程数学模型。

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。