煤矿自燃火灾治理关键技术的研究与应用

介绍了使用同位素测氡法探测煤矿自燃火源位置的原理及应用效果。实践证明,该方法是解决煤矿自燃火灾治理难题的关键技术,由于投资少,精度高,软件处理直观可靠,它有重要推广价值     

雷管空中爆炸压力分布的理论计算

在对８＃ 雷管装药进行简化处理的基础上,其空中爆炸一定范围内的压力场分布可通过理论计算求得。近场参数可用自相似方法求解,而非近场参数又可用ＭａｃＣｏｒｍ ａｃｋ 两步格式对偏微分方程进行数值求解。将获得的压力场与实测结果进行比较,两者基本一致     

Window Sensitivity Functions for Line Transect Sampling

L and width 2w, then by a selection of viewing window is meant a choice of w, with the intent being to search for optimal viewing windows, with the goal in mind of improving variances of estimators of population density, reducing sampling effort, while maintaining the property of unbiasedness. The notions of increasing window sensitivity (IWS) and decreasing window sensitivity (DWS) are introduced, and a method of deriving confidence intervals is discussed.     

Prenatal detection of trisomy 21 in uncultured amniocytes by fluorescence in situ hybridization: A prospective study

A prospective study was undertaken to evaluate the use of fluorescence in situ hybridization (FISH) for the detection of trisomy 21 in interphase nuclei of uncultured amniotic fluid cells. Five hundred cases were analysed in situ and classified as normal or abnormal; the results were subsequently checked against the cytogenetic findings. Four hundred and ninety-three were correctly identified as normal with an 86·6 per cent average frequency of scored nuclei exhibiting two signals; six cases were correctly identified as trisomic for chromosome 21 with 81·7 per cent of scored nuclei exhibiting three signals; and one abnormal case involving an unbalanced chromosome 21·21 translocation was falsely scored as normal due to poor hybridization/detection efficiency. The method has been substantially improved and simplified so that it is suitable for the rapid detection of trisomy 21. As aneuploidy detection in interphase does not identify structural chromosome aberrations, it is not a substitute for fetal chromosome analysis.     

基于负压法炮弹气密性检测方法研究

目的 实现炮弹气密性检测及其自动化、智能化设备的开发.方法 提出了一种基于负压法的炮弹气密性检测方法.首先,阐述了负压法气密性检测工作原理和实施流程,并对炮弹检测设备的用例模型和检测设备功能框架进行了讨论.其次,针对工程实际,详细给出了测量腔安装密封性计算、测量腔泄漏的压差泄漏率计算、测量腔的初始测量压力值计算、炮弹气体泄漏量计算等检测算法和判定方法.结果 基于负压法的炮弹气密性检测方法的灵敏度比正压法高.结论 本方法可为实现对全弹的气密性检验提供参考,同时也可促进和指导炮弹气密性检验设备的研制,将有效保障炮弹气密性检验自动化设备开发效率和有效性.     

Detection of organic pollutants in sandy soils via TDR and eigendecomposition

In this study, organic pollutants in sandy soils are detected using a time domain relectrometry (TDR) probe system and eigendecomposition technique. As a demonstration, four types of organic fluids (motor oil, diesel oil, methanol and ethanol) were examined. Samples were prepared with different combinations of deionized water and organic fluid contents. For each experiment, reflected signals were captured by an oscilloscope, and their characteristics were identified using eigendecomposition technique. Autoregressive modeling and singular value decomposition methods were utilized for calculating the eigenvalues. The most significant eigenvalues were then identified based on their relative magnitude. Experimental results indicated that the presented system is sensitive to both water and pore fluid organic contents. For saturated conditions, signature curves were determined for identification of organic and/or water contents in soil pore fluids.     

新装饰装修房屋室内空气中的苯系物调查

对新装饰装修房屋室内的一类主要有机苯系污染物进行了调查,调查采用吸附柱采集、GC/MS 和GC-FID测定,检测了321家居室内的苯系物.检出的苯系物有12种,苯平均浓度为0.068 mg/m^3,有86.9%的居室符合《室内空气质量标准》（GB/T18883-2002）规定的限量值,甲苯、二甲苯平均浓度分别为0.14 mg/m^3和0.41 mg/m^3,符合《室内空气质量标准》规定限值的居室分别达85.4%和73.3%.苯系物约占室内空气中TVOC的62%,浓度由低到高分别是苯、甲苯、乙苯和二甲苯,其中二甲苯中的间二甲苯占二甲苯总量的55% .     

合肥科学岛低对流层二氧化碳时空分布特征

依据合肥市科学岛2013~2016年的CO₂体积比浓度廓线,分别从夜间、季节和年度分析了亚热带季风气候的CO₂分布特点和合肥科学岛的CO₂源汇特征.（1）大气CO₂体积比浓度随高度增加而减小,390m的CO₂浓度约为15m浓度的95%,夜间随时间推移浓度增加幅度约5%,天亮时CO₂浓度有减小的趋势;（2）测量点高度大于100m时,季节特征较明显,CO₂体积比浓度夏季最低,冬季最高,浓度相差约10×10^-6;（3）测量点高度大于100m时,2013~2016年CO₂体积比浓度的年分布随高度变化的梯度相关系数大于0.9,体积比浓度年增长约2.1648×10^-6.通过三个时间尺度的CO₂体积比浓度廓线分析得出,CO₂浓度特征是动植物活动和大气运动等共同作用的结果;CO₂长期循环过程中,存在近地面CO₂向高空的传输效应.     

高倍泡沫加速泄漏LNG扩散的有效性模拟试验

泡沫灭火剂在扑灭液体火灾中起到重要作用,关于低温液体蒸气云扩散控制的研究也逐渐得到应用。通过小尺寸模拟试验验证高倍泡沫加速泄漏LNG扩散的有效性,设计并进行了低温液体自然蒸发和高倍泡沫覆盖低温液体两个对照试验,测量了竖直方向上10个高度处的温度及装置整体质量,从而获取了低温液体蒸气到达泡沫层顶端时温度及蒸发速率的变化情况。结果表明,与未添加泡沫的情况对比,高倍泡沫的覆盖使泄漏低温液体在1 800 s内的蒸发量减少了6.4%,如果时间更长则减少的比例更多,且蒸发出的低温液体穿过泡沫层后蒸气温度可达0℃左右,而未添加泡沫时同等高度处蒸气温度为-75℃左右。0℃时,LNG蒸气密度已明显小于空气密度,此温度下LNG蒸气会迅速向上扩散,而不至在地表积聚,由此证明高倍泡沫能够加速泄漏低温液体蒸气向上扩散,减小了低温液体蒸气在地面积聚并引发火灾爆炸事故的可能性,从而证实了高倍泡沫加速泄漏LNG扩散的有效性。