基于ANSOFT的永磁同步电机电磁场分析

电机气隙是机电能量转换的重要区域,气隙中的磁通密度是电机设计的重要参数．对7．5kW永磁同步电机,通过有限元分析软件ANSOFT进行建模、定义材料属性和模型属性,经过剖分划网、加载边界条件和负载电流,求解偏微分方程组后,完成后处理,得到永磁同步电机气隙中的磁力线分布图和磁通密度分布图．分析结果为永磁同步电机的优化设计提供指导意义．     

磁通量和感应电动势的变换关系

根据狭义相对论和电磁学原理 ,导出了在两参照系中分别同时测量的磁通量和感应电动势的变换关系     

EXPERIMENTAL STUDY OF GAS—SOLID SUSPENSION FLOWS IN VORTEXING FLUIDIZED BED CHAMBER FREEBOARD

Gas flows and particle mass flux were measured and clutriation experimentswere conducted in two cold test models of vortexing fluidized bed(VFB).The experimen-tal results show that the secondary air injected tangentially creates strong vortexes,estab-lishes particle suspension layers and internal circulation,and suppresses the elutriation offine particles greatly.The vortexing fluidized bed combustion has bright prospect bccauseof its much higher combustion efficiency and desulphidation efficiency than bubblingfluidized bed combustion due to long particle residence time and high slip velocity betweengas and solid,and its simpler configuration and lower cost than circulating fluidized bedcombustion.     

稳恒磁场安培力的功及其能量来源

本文研究含源载流导线回路在稳恒磁场中发生有限的任意移动时，安培力所做的功及其能量的来源。     

经理股票期权激励机制主要障碍及对策

经理股票期权在经营者长期激励与约束方面具有非常重要的意义，但其有效实施需要一系列的条件。本文主要分析在我国实行经理股票期权激励机制面临的主要障碍并提出一些对策。     

论杜邦分析体系的改进

在当前利润操纵严重的情况下,各方利益更关注企业是否有充足的现金流量,传统的杜邦分析体系逐渐显露其弊端。为此,应对传统杜邦分析体系进行改进,在原有的分析体系中引入现金流量指标,使财务分析更全面、综合。     

Liquid film dryout model for predicting critical heat flux in annular two-phase flow

Gas-liquid two-phase flow and heat transfer can be encountered in numerous fields, such as chemical engineering, refrigeration, nuclear power reactor, metallurgical industry, spaceflight. Its critical heat flux （CHF） is one of the most important factors for the system security of engineering applications. Since annular flow is the most common flow pattern in gas-liquid two-phase flow, predicting CHF of annular two-phase flow is more significant. Many studies have shown that the liquid film dryout model is successful for that prediction, and determining the following parameters will exert predominant effects on the accuracy of this model： onset of annular flow, inception criterion for droplets entrainment, entrainment fraction, droplets deposition and entrainment rates. The main theoretical results achieved on the above five parameters are reviewed; also, limitations in the existing studies and problems for further research are discussed.     

土工离心机地下水曝气试验装置研制与试验

针对地下水的修复问题,在50 gt土工离心机上,研制了一套地下水曝气试验装置,该装置包括曝气模型箱、控制与试验量测系统.该装置可满足0.1～5 mm的玻璃微珠材料进行地下水的土工离心曝气模型试验.从2 mm的玻璃微珠的初步试验表明,该系统结构简单,使用方便,可靠性及稳定性好.有效曝气压力与气体质量流量有较好的线性关系,曝气影响区域随着有效曝气压力的增大而增大,最终趋于稳定.     

“活”“动”的政治课

古板的政治课要“活”“动”起来，关键在教师。     

一种电网谐波利用的新方法

电网中的谐波电压和电流本身也是一种能源.利用基于磁通可控可调电抗器原理隔离系统谐波,迫使谐波流入谐波提取侧,通过三绕组变压器和基波磁通有源补偿在不取用系统基波功率的条件下提取含量较大的谐波分量.将提取出的谐波能量直接进行利用,或转化为直流或逆变成交流回馈电网,达到谐波利用的目的.利用MATLAB6.5搭建实际系统模型并对谐波提取进行仿真分析,仿真结果表明在谐波含量较为丰富的地方,本方案能有效滤除和提取电力系统谐波进行利用.