基于面向时间过程的静态安全分析

针对传统静态安全分析基于单一时间断面、无法细致反映系统状态变化的不足,本文提出了一种面向时间过程的静态安全分析方法。首先介绍了面向过程方法的基本概念。充分利用丰富的电力系统测量和负荷预测数据信息,提取了描述每个时间断面的特征向量;结合电力系统负荷连续变化的特点,通过改进的K-means聚类分析技术,对负荷曲线进行了时间过程的划分。定义了提取时间子过程最大特征断面和最小特征断面的指标,并对特征断面的显著代表性进行了研究。在保证电网安全稳定的前提下,本文方法可一定程度上提高传输线路的利用率。最后,IEEE30节点算例表明面向时间过程静态安全分析方法的合理性和有效性。     

源霸二线相间间隔棒掉串分析及对策

本文对大同超高压供电公司运行维护的源霸二线发生断裂相间间隔棒的运行、结构、强度、安装等情况进行了分析,并在此基础上提出了防止相间间隔棒断裂反事故措施。     

电动机常见故障与处理方法

大部分电机属于老式电动机,使用年限较长,电机烧毁的事故常有发生,而且呈上升趋势,无法长期可靠运行,严重影响着生产、生活的安全。通过作者多年积累的电机维护、维修的经验,针对一些电动机最常见的绕组故障、机械故障以及相应判断、处理做以简单介绍。     

Snowstorm caused chaos but risk free to power grid

<正>From January 1 to 3,2010, the heaviest snow for decades in North China caused widespread chaos in traffic and people's livelihood, but there was no risk to power grid.     

Hainan Changjiang nuclear power project construction started

<正>On April 25, the Hainan Changjiang nuclear power project, jointly invested by China National Nuclear Corporation (CNNC) and China Huaneng Group with 51% and 49% shares, respectively, formally began     

World’s new highest arch dam emerged

<正>On March 8, 2010, the concrete pouring was completed on the dam crest in the state’s key project, Yunnan Xiaowan Hydropower Station. Consequently,     

四合一天线合路器的控制与实现

介绍了一种基于FPGA控制的四合一天线合路器,该合路器能够根据4部电台的不同频率选择正确的通信信道,并将其信息传送到一路天线上进行通信。文中介绍了该合路器的硬件结构,软件控制算法以及工程上的实现方法。测试表明,该天线合路器能够满足4部电台同时在一路天线上进行接收与发送的要求,具有广泛的实用价值。     

Brazil’s Petrobras Keen on Cooperation with China

Brazil’s state-controlled oil and gas giant Petrobras is analyzing future cooperation opportunities with Chinese companies,the company’s CEO Jose Sergio Gabrielli said in an interview with Xinhua in Rio de Janeiro in late     

Unintentionally produced dioxin-like polychlorinated biphenyls during cooking

The formation and distribution of dioxin-like polychlorinated biphenyls (dl-PCBs) during cooking was investigated. Concentrations of dl-PCBs in liquid residues, cooked beef, and oil fumes generated during heating were determined by isotope dilution HRGC/HRMS. Although the levels of dl-PCBs in well-done beef were lower compared with those of raw beef, relatively high concentrations of dl-PCBs were detected in the oil fumes produced during heating. This suggests that dl-PCBs in raw beef may have volatilized into the oil fumes during the cooking process. Sucralose and chloropropanols contained in raw materials may have resulted in increased dl-PCB concentrations and the level of toxic equivalents (TEQ) in the oil fumes produced under high temperature during cooking. Concentrations of dl-PCBs did not vary greatly in cooked beef, except when higher levels of chloropropanols were presented in the uncooked raw materials. Results indicate that sucralose and chloropropanols may promote the formation of dl-PCBs during the cooking process. The newly produced dl-PCBs from raw beef cooking were mainly present in oil fumes, which gave rise to high levels of TEQ in oil fumes.     

Application of electrolyzed functional water on producing mung bean sprouts

Electrolyzed functional water possesses a wide variety of antimicrobial activities. Electrolyzed functional water, which used to take place of tap water in producing mung bean sprouts, was studied in this paper. The results showed that electrolyzed water can not only reduce the quantity of microorganism on the surface of mung bean sprouts, but also promote the growth of sprouts. Further research showed that electrolyte leakage rate of mung bean soaked in electrolyzed water was the lowest, while the catalase’s activity of mung bean soaked in electrolyzed water was the highest. All of these contribute to the high activity of mung bean.