屋面渗漏的成因及PVC防水材料的应用

分析了屋面渗漏的成因，介绍了ＰＶＣ新型防水油膏的特点及施工方法。     

化工厂减速器频繁损坏的故障分析和处理

针对减速器运行时出现的润滑油泄漏、异响等故障,详细地分析了故障原因,并提出了相应的解决方案和改进措施。     

架空天然气管道泄漏扩散过程特性分析

在天然气管道集输过程中,由于管道老化、腐蚀等因素引起的泄漏事故时有发生,会引起穿孔泄漏后的天然气扩散,可能会引发火灾、中毒或爆炸。因此,进行架空天然气管道泄漏扩散过程的影响因素模拟研究及分析,对天然气管道输送安全运营和保障人生财产安全意义重大。文章建立了架空天然气管道在迎风坡和背风坡处发生泄漏扩散过程的物理模型,并利用CFD软件对架空天然气管道泄漏后的甲烷气体扩散过程进行了数值模拟。结果表明：泄漏的甲烷气体扩散范围和速度非常大,在泄漏时间300S时泄漏距离已经达到40m,并在40m处形成高浓度的甲烷气团;泄漏点在背风坡时,山坡附近形成高浓度甲烷气团。     

On Composite Leakage Current Maximization

Sub-threshold, gate and reverse biased junction band-to-band tunneling leakage currents depend on the logic inputs of a CMOS circuit. In this paper, we consider all leakage currents together and generate pattern with the objective of maximizing the overall leakage current to avoid any optimism in leakage current estimation. The computation involves Boolean reasoning on a pre-characterized set of interconnected gates. This problem is known to be computationally intractable. We propose a heuristic with reduced complexity by looking for a lower and an upper bound instead. The bounds tighten progressively with computation and converge asymptotically on a provably exact solution. By appropriately setting the objective function, the same algorithm may also be applied to find the pattern that minimizes the leakage power in the system idle state, which is considered to be ∼50% of the total power consumed in the current technology generations.

输油气钢管腐蚀渗漏原因分析

某油井钢管使用不到一年即发生渗漏。采用化学分析、力学性能测试、金相及超声波检验和电镜能谱分析等方法，对渗漏钢管进行了分析。结果表明，该钢管实为焊管，不是技术规范所要求的无缝钢管。加上该焊管的焊接质量较差，加速了输送介质对焊管的腐蚀，最终导致焊管短期内发生渗漏。     

基于零序电流方向的选择性漏电保护系统的研究

在分析国内外漏电保护装置现存问题的基础上,文章提出了一种基于零序电流方向的矿井低压电网选择性漏电保护系统,重点讨论该系统的工作原理,硬件结构,软件设计及抗干扰技术,最后介绍试验结果和应用情况。     

一种新颖的半导体光放大器镀膜监控方法

本文介绍了一种在半导体光放大器镀膜过程中监测端面反射率的简单而有效的方法。理论模型的建立考虑了光放大器的漏电流和自发发射速率随载流于浓度的非线性变化，并且基于实验测量的ＰＩ（输出功率与注入电流）曲线，采用曲线拟合的方法来修正一些依赖于器件的参数，理论计算结果与有关文献的测量结果较好地吻合。     

煤矿井下漏泄通信系统抗干扰技术

通过对煤矿井下电磁干扰测试和分析,发现井下电磁干扰主要有白噪声、脉冲干扰及窄带干扰。提出采用扩频通信、信道采用交织编码结合前向编码以及自适应傅立叶变换抑制窄带干扰等技术来抑制电磁对煤矿井下漏泄通信系统的干扰。     

Approximation of Well Function and Identification of Leaky Aquifer Parameters

The existing equation for leaky aquifers is transformed into a nondimensional form using new parameters and a scaled well function for leaky aquifers is proposed. A computationally simple function is developed for accurately approximating the scaled well function for the practical range of the parameters. Utilizing this function (approximation), an optimization method is proposed for identifying the leaky-aquifer parameters from observed drawdowns. The new function has an enhanced utility when a repetitive numerical evaluation of the well function for leaky aquifers is needed, e.g., while estimating the aquifer parameters using optimization or Kalman filter or artificial neural network methods. The application of the proposed method is illustrated using a few sets of published data. The proposed method outperforms the extended Kalman filter method, based on the reported results in the literature.     

500kV并联电抗器色谱监测与故障诊断

通过对一台 5 0 0kV高压并联电抗器的色谱分析测试 ,分析了造成高压并联电抗器过热的原因 ,介绍了具体的改造方法和改造后的运行状况。