北京市春夏季大气气溶胶的单颗粒分析表征   总被引：9，自引：0，他引：9  

肖锐刘成德  梁汉东董树屏 F．Adams 《岩矿测试》2004,23(2):125-131

采集了北京市2000年春夏季大气气溶胶样品5个，采用扫描电镜X射线能谱技术分析大气气溶胶单颗粒约2500个。研究结果表明，沙尘期间，矿物尘是最主要的颗粒物种类，非沙尘期间，北京市大气气溶胶中主要检出矿物尘和含硫颗粒物。夏季随着颗粒物污染的加重，含硫颗粒物的数目百分数增加。是北京市大气颗粒物污染的重要特征。重点讨论了Ca-S颗粒、K-S颗粒和Ca-K-S颗粒三类典型含硫颗粒物的化学组成和粒径分布特征。数目可观的Ca-K-S颗粒以及其他硫酸盐颗粒的生成与相对湿度和云量等气象条件相关，这些颗粒物可能是云中过程的产物。减少SO2排放，减少含硫颗粒物，对于控制北京市的大气颗粒物浓度水平具有重要意义。  相似文献   

测试超细煤粉粒度的实验研究     

陈杰 《岩矿测试》2004,23(3):183-186

利用激光粒度仪测试超细煤粉的粒度。对测试超细煤粉试样粒度时的试样浓度、测试温度、分散时间、分散剂的种类及浓度等方面的影响进行了实验研究，给出了激光粒度仪测试超细煤粉粒度的最佳实验条件。  相似文献   

化学腐蚀下砂岩三轴细观损伤机理及损伤变量分析   总被引：10，自引：4，他引：10  

陈四利  冯夏庭  周辉 《岩土力学》2004,25(9):1363-1367

利用CT识别技术对化学腐蚀下的砂岩进行了三轴加载全过程的即时扫描试验，得到了在不同级荷载作用下砂岩的压密、微裂纹萌生、扩展和破裂的CT图像和CT数，分析了砂岩损伤演化的细观机理。同时，建立了一个基于化学腐蚀影响和CT数的损伤变量模型。  相似文献   

广东茂名高岭土煅烧实验研究   总被引：1，自引：0，他引：1  

朱粉利  曾伟能  王勤燕  周汉文 《矿产与地质》2004,18(2):168-172

对茂名高岭土进行煅烧，结合X-射线衍射、扫描电子显微镜分析，得到了茂名高岭土在不同温度点煅烧的性能参数，并确定出其非晶化转变的温度是550℃。同时对煅烧过程中的煅烧温度、恒温时间等影响因素进行探讨，结果表明，在茂名高岭土的煅烧过程中，适当延长恒温时间可降低非晶化转变的温度，缩短恒温时间，则非晶化转变温度升高。  相似文献   

鄂尔多斯盆地中生代晚期以来大地热流的变化及其对生态环境格局和演变的影响     

匡耀求  黄宁生  胡振宇  吴志峰  刘宇 《矿物岩石地球化学通报》2004,23(4):318-325

鄂尔多斯盆地的西北部、东北部和南部三个区域现今大地热流平均值分别为56．3、67．3和65．3mW／m^2，对应的生态环境格局也有明显的差异。研究表明，大地热流每增加4～5mW／m^2可使年均地表温度升高约l℃，使最低月均地表温度升高2。C以上。鄂尔多斯盆地东北部的平均大地热流比西北部高出11mW／m^2，东北部年均地表温度可能比西北部高出2～3℃，其最低月均地表温度可能比西北部高出4～6℃。西北部的大地热流平均值已经低于维持地表生态系统延续所需大地热流的临界值(57mW／m^2)，其自然生态系统整体上已经处于脆弱境地；东北部和南部的大地热流均大于57mW／m^2，自然生态系统均尚较稳健。东北部的沙漠化可能是风沙侵入的结果，其生态应该是可以恢复的。整个西北部作为一个整体看，72万年以前大地热流就已衰减到临界值以下，区域生态系统渐趋脆弱，开始整体上向荒漠化演变。  相似文献   

Accurate U-Pb Age and Trace Element Determinations of Zircon by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry   总被引：190，自引：0，他引：190  

Honglin Yuan  Shan Gao  Xiaoming Liu  Huiming Li  Detlef Günther  Fuyuan Wu 《Geostandards and Geoanalytical Research》2004,28(3):353-370

Various zircons of Proterozoic to Oligocene ages (1060-31 Ma) were analysed by laser ablation-inductively coupled plasma-mass spectrometry. Calibration was performed using Harvard reference zircon 91500 or Australian National University reference zircon TEMORA 1 as external calibrant. The results agree with those obtained by SIMS within 2s error. Twenty-four trace and rare earth elements (P, Ti, Cr, Y, Nb, fourteen REE, Hf, Ta, Pb, Th and U) were analysed on four fragments of zircon 91500. NIST SRM 610 was used as the reference material and ²⁹Si was used as internal calibrant. Based on determinations of four fragments, this zircon shows significant intra-and inter-fragment variations in the range from 10% to 85% on a scale of 120 μm, with the variation of REE concentrations up to 38.7%, although the chondrite-normalised REE distributions are very similar. In contrast, the determined age values for zircon 91500 agree with TIMS data and are homogeneous within 8.7 Ma (2 s ). A two-stage ablation strategy was developed for optimising U-Pb age determinations with satisfactory trace element and REE results. The first cycle of ablation was used to collect data for age determination only, which was followed by continuous ablation on the same spot to determine REE and trace element concentrations. Based on this procedure, it was possible to measure zircon ages as low as 30.37 0.39 Ma (MSWD = 1.4; 2 s ). Other examples for older zircons are also given.  相似文献   

Fluid core resonance revealed from a laser extensometer at the Rokko-Takao station, Kobe, Japan     

Atsushi Mukai  Shuzo Takemoto  Takeyasu Yamamoto 《Geophysical Journal International》2004,156(1):22-28

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地图扫描数字化的质量分析与评价     

蒋辉 《现代测绘》2004,27(5):46-48

通过分析地图扫描数字化的误差因素．运用质量控制图评价学生实验数据质量，能够直观地对学生实验数据做出判断，同时也能比较各个实验小组及班级之间总体实验水平，及时发现实验准备工作中及实验方法本身的有关问题。  相似文献   

基于扫描矢量化地图数据生产的数据质量控制   总被引：2，自引：0，他引：2  

陈洪艳  陈宜金  游代安  郭建星 《测绘信息与工程》2004,29(4):31-33

概述了基于扫描矢量化GIS数据的生产过程 ,介绍了扫描矢量化质量控制的策略和方法 ,在地图扫描阶段采用栅格图纠正的方法对地图的变形进行纠正 ,以提高矢量化原图的质量 ,在基于扫描矢量化GIS数据的生产过程中 ,可从算法和软件使用工艺方面提高数据的质量  相似文献   

Laser Ablation ICP-MS Developments and Trends for 2003     

Paul J. Sylvester 《Geostandards and Geoanalytical Research》2005,29(1):41-52

This annual review of laser-ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) covers the year 2003. Significant advances were made in understanding laser-sample interactions. In particular, research defined the distribution of particle sizes produced by the interplay of laser wavelength, laser pulse width and the gas environment of ablation. A link between particle sizes and elemental and isotopic fractionation at both the ablation site and in the ICP was established. Experimental 15 7 nm and femtosecond laser systems were tested with promising results. The number of applications of LA-ICP-MS in geology and environmental Earth science continued to grow with particular interest in element concentration and isotope ratio profiling of materials, linking composition to time scales. In situ isotopic ratio measurements were increasingly made using multicollector magnetic sector ICP-MS instruments. Other applications of wide interest included bulk sampling of rocks and ores prepared as lithium borate glasses; low level analysis of platinum-group elements, rhenium and gold in sulfides, metal and silicates; in situ uranium-lead zircon geochronology; and melt and fluid inclusion analysis.  相似文献