电能质量及其测量系统综述

概述了电能质量问题的背景,论及了电能质量问题的现象、危害以及现有的改善手段;着重论述了电能质量的测量,介绍了电能质量的几种分析方法以及测量系统;最后,提及了电能质量测量系统的新技术.     

三种主流宽带小区接入方式的比较与研究

通过对ADSL、LAN、HFC三种宽带接入方式原理及实际应用范围,并从运营商和用户两个角度对宽带小区接入方式的优劣予以阐述.     

A Software Tool for Automatically Verified Operations on Intervals and Probability Distributions

We describe a software tool for performing automatically verified arithmetic operations on independent operands when the operands are intervals, or probability distribution functions, or one operand is an interval and the other is a distribution. Intervals and distributions are expressed using the same technique, so the algorithms do not need to distinguish between intervals and distributions in their operation. The tool can calculate common arithmetic operations with guaranteed results (as well as confidence limits on a distribution if the distribution is empirically estimated from samples).A previous paper [1] discusses the concepts, algorithms, and related work. Here we emphasize a software tool that implements the algorithms, interacts with the user via a graphical user interface, and saves, retrieves, and prints the results of its calculations.     

稀土材料新进展

叙述了稀土材料的新种类以及应用前景，并对国内稀土工业的现状及其存在的问题、国外稀土市场概况进行了综述，同时，展望了我国稀土材料的发展方向。     

The influence of temperature, pressure, salinity and capillary force on the formation of methane hydrate

We present here a thermodynamic model for predicting multi-phase equilibrium of methane hydrate liquid and vapor phases under conditions of different temperature, pressure, salinity and pore sizes. The model is based on the 1959 van der Waals-Platteeuw model, angle-dependent ab initio inter- molecular potentials, the DMW-92 equation of state and Pitzer theory. Comparison with all available experimental data shows that this model can accurately predict the effects of temperature, pressure, salinity and capillary radius on the formation and dissociation of methane hydrate. Online calculations of the p-T conditions for the formation of methane hydrate at given salinities and pore sizes of sediments are available on: www.geochem-model.org/models.htm.     

JYL210E型轮胎式挖掘机底盘开裂的修复与加固

济钢第一炼钢厂JYL210E型轮胎式挖掘机工作700h后,出现大架撕裂、底盘裂纹现象,无法安全使用,对此进行修复加固。通过采取加固后桥、增加辅助钢板、焊补底盘和斗杆等措施,挖掘机整车强度提高了3.5倍、刚度增加了6倍,提高了使用性能和安全性能,节约采购资金200多万元。     

单试样三点柔度法测金属材料JR曲线及其条件起裂值

在单试样卸载柔度法及单试样三曲线法基础上,提出了一种更简便的测定金属材料ＪＲ曲线及其条件起裂值的单试样三点预先度法,并用该方法测定了１Ｃｒ１／２Ｍｏ钢、１６ＭｎＲ风和ＷＣＦ６２钢的ＪＲ曲线及其条件起裂值,与标准的多试样法相比,误差均在工程许可范围内。     

An Ensemble Classification Algorithm Based on Information Entropy for Data Streams

Data stream mining has attracted much attention from scholars. In recent researches, ensemble classification has been wide aplied in concept drift detectio     

基于函数插值的柯氏质量流量计信号处理方法

对基于离散傅里叶变换(DFT)信号处理方式的柯氏质量流量计来说,影响其精度的关键问题是如何实现信号的整周期采样。提出了一种全新的方法,用采样率固定不变的采样数据,通过软件实时地确定信号的频率并且实现信号整周期重新采样。实验结果表明该方法在求取相位差时具有极高的精度。