基于开关磁阻电机的车用起动-发电-助力一体化系统研究

针对基于开关磁阻电机的车用起动-发电-助力一体化（ISAD）系统，分析其主要工况（起动，助力，发电）状态下控制策略并给出仿真波形。同时采用TMS320F240型数字信号处理器和EPM7128S型复杂可编程逻辑门阵列构成核心控制器。最后以1kW三相6／4开关磁阻电机为样机完成起动-助力-发电实验，给出了实验波形和分析结论。实验结果表明，该控制器及其控制策略是有效的，基于开关磁阻电机的车用ISAD系统在工程实践上是可行的。     

Thermal and dielectric properties of ZnO-B2O3-MO3glasses (M = W, Mo)

Glasses in the ZnO-B₂O₃-MO₃(M = W, Mo) ternary were examined as potential replacements to PbO-B₂O₃-SiO₂-ZnO glass frits with the low firing temperature (500–600^∘C) for the dielectric layer of a plasma display panels (PDPs). Glasses were melted in air at 950–1150^∘C in a narrow region of the ternary using standard reagent grade materials. The glasses were evaluated for glass transition temperature (T _g ), softening temperature (T _d ), the coefficient of thermal expansion (CTE), dielectric constant (ε _r ), and optical property. The glass transition temperature of the glasses varied between 470 and 560^∘C. The coefficient of thermal expansion and the dielectric constant of the glasses were in the range of 5–8 × 10^{− 6}/^∘C and 8–10, respectively. The addition of MO₃to ZnO-B₂O₃binary could induce the expansion of glass forming region, the reduction of T _g and the increase in the CTE and the dielectric constant of the glasses. Also, the effect of the addition of MO₃to ZnO-B₂O₃binary on the transmittance in the visible-light region (350–700 nm) was investigated.     

火电机组AGC功能在黑龙江电网的应用

从普遍意义上阐述了AGC是为电网提供调频服务,电网应对其考核和补偿.给出了黑龙江电网AGC作用、控制策略、考核和补偿标准.从分析目前发电厂对AGC积极性不高的问题出发,阐述了随着电力市场改革的发展应对现行AGC规则进行改进和完善.     

家庭UPS选购经验谈

1 UPS种类常见的UPS一般分为在线式、后备式和在线互动式三种。在线式UPS在工作时,先将输入的市电降压、整流,滤波为低压直流电给蓄电池充电,同时蓄电池将直流电再通过高质量的逆变器转换为高质量的正弦波交流电输出给计算机。而停电时,由UPS内的蓄电池直接给逆变器供电,输出高质量的正弦波交流电。由于在线式UPS的逆变器始终处于工作状态,因此     

鸡冠花红褪色光度法测定羟自由基

研究了以食用色素-鸡冠花红为指示,氧化褪色光度法测定Fenton反应产生的羟自由基.在硫酸介质中,羟自由基能够氧化鸡冠花红褪色,在520nm波长处测定吸光度值的变化,可间接测定羟自由基的量.该法所用仪器简单,试剂廉价易得,操作简便,稳定性好,可作为一种筛选羟自由基清除剂的方法.     

升温氧化过程煤表面介观特征和分形参数研究

将原子力显微镜（AFM）用于煤表面结构研究,提出介观尺度下煤表面结构研究方法. 得出基于分形理论和AFM观测结果计算分形维数D的方法.实验分析证明,煤表面有明显的分形特征,在煤样的升温氧化过程中,分形维数随温度的升高趋于增大.     

Estimation of forest volumes by integrating Landsat TM imagery and forest inventory data

Accurate information about forest volumes is essential for forest management planning. The survey interval of the Forest Resource Inventory of China (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was 44.2%, much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%, respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.     

A database framework of digital forestry towards sustainable forestry development in China

Six forestry scientific and technological projects being actualized in China were the implementations of ecological construction and security, development of forestry biological technique and fine variety cultivation, protection and utilization of forest biological germplasm resources, development of forestry bio-industry and digital forestry, and construction of forestry innovation ability. Among them, digital forestry was an effective measure to improve the ability of forestry innovation, to realize resources sharing, and to develop sustainable forestry. Spatial database of digital forestry should be constructed according to the criteria and index system of forest sustainable management. Based on analyzing the status and advances of China’s digital forestry construction, a database framework of digital forestry towards sustainable forestry development was studied and established preparatorily. The database was divided into four layers as theory layer, system layer, status layer, and parameter layer. It was concluded that during the process of digital forestry platform construction, the relative social, economic, and politic data should be considered and collected, which meant that the database should represent not only the current forestry development, but also the social, politic, and economic situations. Constructing China’s digital forestry information platform under full utilization of idea and index system for sustainable forest management was urgent and important.     

论全球化供应链管理的延迟运作战略的应用——基于惠普(HP)和戴尔(DELL)公司的成功案例

在介绍延迟运作理论的基础上,结合惠普、戴尔两大公司根据自身的具体条件和特点实施延迟运作战略的案例分析,介绍了其成功运用的供应链运作战略,分析了全球化供应链管理中实施延迟运作战略的条件,指出了延迟运作战略在21世纪全球化供应链管理中的巨大作用。     

国家电网安监[2005]83号中绝缘工器具的若干问题

国家电网公司国家电网安监[2005]83号发布的《国家电网公司电力安全工作规程(变电站和发电厂电气部分、电力线路部分)(试行)》文件中对电力绝缘工器具有若干规定是错误的或不准确的,因此有必要对新安规绝缘工器具的规定进行探讨。