稳压泵在建筑灭火给水系统中的应用

介绍稳压泵用于消防给水系统的工作原理,并结合工程设计实例对带有小气压罐的稳压泵消防给水系统进行了技术经济分析,提出在保证消防电源的情况下,稳压泵消防给水系统可以视作常高压消防给水系统。     

地面树木的最优标记分水岭图像分割算法

为解决复杂地物背景下航拍图像树木检测出现的过分割和误分割问题,提出了一种基于最优标记的改进分水岭图像分割方法。该方法先对输入图像非线性灰度变换提高目标与背景的对比度,再根据目标的形状特征对前景和背景区域初步标记,用前景区域的形心代替传统分水岭算法中的距离变换,二次标记前景,最后使用分水岭算法得到分割图像。实验结果表明,该算法分割准确率平均值为92.5%,比现有图像分割方法抗噪性更强、准确率更高,同时改善了分水岭算法过分割问题。     

Spectroscopic properties of Bi2ZnOB2O6 single crystals doped with Pr3+ ions: Absorption and luminescence investigations

Nonlinear optical Bi₂ZnOB₂O₆ single crystals doped with Pr³⁺ ions were grown using the Kyropoulos method. The absorption and luminescence properties of these new systems were investigated for the first time. The crystals are characterized by the large values of nonlinear optical coefficients. Effective luminescence of the Pr³⁺ ions makes this system an excellent candidate for the near-infrared (NIR) and/or ultraviolet (UV) to visible (VIS) laser converters. Based on the obtained experimental spectroscopic data, detailed analysis of the absorption and luminescence spectra was performed using the conventional Judd–Ofelt theory. Those transitions, which can be potentially used for laser applications of the Pr³⁺ ion, have been identified. In addition to the intensity parameters Ω₂, Ω₄, Ω₆ the branching ratios and radiative lifetimes were estimated for all possible transitions in the studied spectral region.     

道清矿巷道支护计算机辅助设计系统研究及应用

在分析道清矿地质条件的基础上,结合现有锚杆(锚索)支护理论、影响锚杆支护可靠性因素,并针对大倾角煤层的巷道围岩变形特征,采取非对称性支护方式。用数字矿山管理软件中的巷道设计支护子系统为道清矿进行锚杆支护设计,通过计算机软件进行支护方式的选择、断面形状的选择、为巷道围岩设定围岩系数、设定围岩参数等,使计算机自动生成巷道断面图。节省了工作量,同时保证了支护设计的准确性、科学性,为巷道支护设计领域开辟了新的途径。     

深埋爆炸波传播规律及边界条件转换分析

以弹性空腔膨胀为研究对象,在爆炸等效荷载理论以及弹性波理论的基础上,建立了深埋地下爆炸波传播模型,并利用速度和应力两种边界条件下运动场势函数相等的原理,建立了球面波运动场中速度场与应力场的转换关系。结果表明：不同于平面波中应力和速度的线性关系,球面波中应力与速度转换关系要复杂的多,相同应力条件下,球面波上的质点的速度要小,影响这种差异大小的主要因素是波的传播距离和介质中波的传播速度。     

一种适用于可靠性评估的电网设备时变停运模型

建立精确的元件停运模型是电力系统中长期可靠性评估的基础工作,现有的元件停运模型通常不能反映元件时变的运行工况和维修对元件的影响。采用阶梯函数来近似模拟元件老化故障率曲线,并基于更新过程理论建立了元件时变停运模型。该模型可以反映中长期可靠性评估中时间对老化故障率的增长效应和维修对老化故障率的降低效应。实际的变压器算例表明,该模型适合模拟任意老化故障率曲线,可用于老化模式已知的元件寿命分布函数和可用度稳态值的评估。相比于传统模型,所提模型具有更好的精度和更广的适用性。     

粉煤灰吸附处理含铬废水的试验研究

利用经2 mol/L的硫酸改性的粉煤灰,来研究粉煤灰吸附处理实验室模拟含铬废水。实验结果表明：处理100 mL含六价铬浓度为50 mg/L的废水,调节pH值2～3,投加8 g改性粉煤灰,反应80 min后六价铬的去除率达到90%以上;吸附符合Freundlich等温吸附式。利用粉煤灰吸附处理含铬废水,具有处理效果好,操作简单,运行费用低等优点,因此,粉煤灰可以作为一种有效的吸附剂来处理含铬废水。     

CFRP加固混凝土梁端钢板锚固分析

研究碳纤维布加固钢筋混凝土梁端部的锚固构造,以解决现行端部锚固构造做法较少且较复杂的问题。对钢板锚固的梁进行水平荷载作用下的试验研究及有限元分析。通过分析试件及对比件的受力、变形及破坏特征等,从而对锚固效果进行研究。结果表明钢板锚固效果良好。     

The corrosion of a Fe-15 wt.% Ce alloy in coal gasification type atmospheres at 600 to 800 °C

The corrosion of a Fe-15 wt.% Ce alloy and of the two pure metals have been studied at 600 to 800 °C in H₂-H₂S-CO₂ mixtures providing high-sulfur and low-oxygen activities that are typical of coal gasification atmospheres. The alloy corrodes more slowly at 600 to 700 °C than pure Fe, more rapidly than pure Ce, while at 800 °C it corrodes at about the same rate as pure Fe. The scaling kinetics of Fe-15Ce are irregular and generally intermediate between linear and parabolic. The scale formed on Fe-15Ce shows a multilayered structure, including an outermost layer of base metal sulfide (FeS), an intermediate complex layer composed of a mixture of compounds of the two metals, and finally an innermost region of internal attack of Ce by both oxygen and sulfur. Ce is not able to diffuse outward in the metal substrate and remains in the alloy consumption region. In the intermediate region, FeS forms a continuous network that allows the growth of an external iron sulfide layer. A Ce content of 15 wt.% is insufficient to prevent the sulfidation of the base metal. These results as well as the scale microstructure are interpreted by taking into account the limited solubility of Ce in Fe and the presence of Ce-rich intermetallic compounds in the alloy examined.