Development of techniques for monitoring gas-phase sodium species formed during coal combustion and gasification     

B. L. Chadwick  R. A. Ashman  A. Campisi  G. J. Crofts  P. D. Godfrey  P. G. Griffin  A. L. Ottrey  R. J. S. Morrison 《International Journal of Coal Geology》1996,32(1-4)

The development of techniques suitable for on-line analysis of gas-phase molecular sodium species, resulting from the combustion and gasification of low-rank coals is described. In particular two techniques have been demonstrated, these are: (a) laser-induced photofragment fluorescence and (b) microwave spectroscopy. The photofragment technique can be applied in situ and yields excellent detection limits (<0.1 ppb of NaCl and 1 ppb NaOH) with good discrimination between the two major gas-phase species — NaCl and NaOH. Limitations of this technique include absorption of the ultraviolet (UV) photolysis excitation by other chemical species and particulates. Microwave spectroscopy shows promise in determining the sodium species distribution in the gas-phase. A purpose built analytical instrument (known as MILLIJET HT) is being developed for application in high-temperature environments. Early results indicate detection limits of <100 ppb NaCl. Lack of sensitivity for NaOH is being attributed to the formation of NaOH dimers and larger clusters. Detailed calculations of the dimer structure and the dimer-monomer reaction have been undertaken in order to maximise the performance of the instrument.  相似文献   

Detection and hydrologic modeling of aquifers in unconsolidated alluvial plains through combination of borehole data sets: a case study of the Arao area, Southwest Japan     

Katsuaki Koike  Hidehumi Sakamoto  Michito Ohmi   《Engineering Geology》2001,62(4):301-317

In addition to spatial distribution of groundwater-flow parameters, aquifer properties of location and shape are also significant for assessing groundwater resources because they strongly affect water flow. We present a selection of geologic data suitable for aquifer analysis, a mathematical method of processing them, and a combination of several maps produced by it. The data used in the analysis are typically obtained by borehole investigation. Our targets are the areas underlain by geologic bodies with different ages and lithologies; the spatial correlation structures of geologic data over the areas tend to change locally. The processing method should be a versatile one that is applicable to areas where geostatistical stationarity is not satisfied. The aquifer analysis consistent with that requirement consists of two steps: the first is the transformation of screen locations, locations of sand and gravel layers, and resistivity by electric logging into indicator values, and the second is three-dimensional interpolation of these using the optimization principle method to produce three kinds of distribution models. A stochastic simulation is also used for modeling the resistivity distribution. The three distribution models are integrated to generate a value for evaluating the possibility of aquifer existence. A case study of an alluvial coastal plain, situated in southwest Japan, describes an aquifer model that contains three permeable layers. Each layer has about 10-m thickness and is lens shaped. To confirm the validity of the model, we have drilled two wells that reached one of the middle and bottom permeable layers, observing the water level change. Low correlation of the temporal changes of levels between the wells indicates that the two layers are hydrologically independent of each other. Additionally, groundwater-flow patterns have been estimated by transforming the simulation model parameter into hydraulic conductivity through a simple function and using a finite difference method for flow analysis. The procedure proposed by this study can be applied to other areas by changing the weights assigned to each geologic and geotechnical factor in the generation of the coefficient for aquifer existence, considering the reliability of each factor and hydrologic properties of study area.  相似文献   

流动式CuBr激光器的设计     

马秦生  赵凤琴 《测绘信息与工程》1996,(1)

给出了流动式ＣｕＢｒ激光器的设计方法并着重讨论了放电管和缓冲气体对激光输出功率的影响。  相似文献   

我国不同景观区SIR与MSS图像影像特征对比     

史继忠 《国土资源遥感》1996,7(4):1-8

通过对罗布泊、华北平原、吕梁山、巴丹吉林沙漠、新疆柯坪地区等地区的航天飞机成像雷达(SIR)图像与陆地卫星多波段扫描图像的对比研究,总结了两种图像上风蚀地貌、平原区河流、村镇、黄土高原山地水系以及沙漠、基岩的影像特征,并初步分析了两种图像成像机理,指出了两者解译效果的差异,对不同研究对象选择最佳信息源有一定参考。  相似文献   

南北地震带中段深部构造与地震     

梁桂培  李渭娟 《内陆地震》1996,10(1):15-22

南北地震带中段位于中国大腹部，是青藏块体、华北块体和扬子块体的中间枢纽部位。根据该区布格重力异常图，采用Ｐａｒｋｅｒ’ｓ三维位场方法进行莫氏面反演并计算该区不同窗口的剩余场推断和解释了条岩石圈断裂，进而研究它们与地震的关系。  相似文献   

三维重磁交互解释及区域与局部异常的分离   总被引：6，自引：0，他引：6       下载免费PDF全文

林振民  陈少强 《地球物理学报》1996,39(5):705-711

探讨了三维重磁交互解释的方法技术，提出构制任意形状三维物体模型的用于计算机的橡皮膜技术．针对通常分离区域与局部异常所存在的问题，提出在异常交互解释过程中同时进行异常分离的方法，并提出相应的算法．最后介绍一个应用实例．  相似文献   

激光在天空对地观测中的应用   总被引：1，自引：0，他引：1  

刘基余 《测绘工程》2001,10(2):15-19

1960年7月世界上第一台激光器问世后，激光测距迅速兴起，不管是地面激光测距，还是激光测卫和激光测月，都为大地测量学的发展作出了重大贡献；特别是激光测卫测月成果，为我们深化对地球动态效应的认识，揭示地球的奥秘，提供了许多重要的科学数据，本文综析了值得注视的下列新近发展。.在IGEX-98国际大联测中，求定GLONASS卫星的激光轨道与微波轨道之差；.评定PRN05/06号GPS卫星星历的精度；.检核Topex/Poseidon海洋测高卫星用GPS定轨的测量误差，.用机载激光测深系统测量海水的浓度；.用EOS-ALT星载激光测距/测高系统测量地球动态参数。  相似文献   

鸭嘴阀扩散器紊动射流特性试验研究   总被引：3，自引：0，他引：3       下载免费PDF全文

唐洪武  李行伟 《水科学进展》2001,12(2):153-159

采用超声多普勒流速仪(ADV)和激光诱导荧光技术(LIF),对鸭嘴阀扩散器的紊动扩散掺混特性进行研究,结果表明:当在出口下游12.5D(D为孔径)范围内,鸭嘴阀扩散器的在主、次轴平面内的射流扩散特性有明显的差异,出现"轴开关"现象,在此区域内,紊动强度也较圆孔射流高出几倍;远区,射流扩散特性与圆射流相似.  相似文献   

构造变形/变质作用的精细测年及其在造山带研究中的应用   总被引：10，自引：0，他引：10  

闫全人  王宗起  闫臻  郑亚东  吴春明  胡世玲  桑海清  王涛 《地学前缘》2001,8(3):147-156

最近几年 ,增生造山过程中构造变形 /变质作用及其精细年代学研究正成为造山带研究的热点之一。造山带内部大型剪切带的运动、变形 /变质事件的精细定年对深入研究增生造山过程具有重要意义。通过把精确的测年数据与约束运动学的、变形 /变质的显微组构结合起来 ,可以比较精细地重建或复原造山带内部不同构造块体增生拼贴的精细时空过程 ,以及建立与之相一致的造山带形成的应变热模式。同时 ,近 3～ 4年的研究结果也表明 ,构造变形 /变质精确定年还存在许多难点 ,如变形矿物形成机制对其测年结果的影响、变形矿物粒度大小对定年结果的制约关系、以及构造变形 /变质过程中矿物同位素体系的变化机理对测年理论与技术质疑等。文中详细介绍了国外目前有关增生造山作用研究的一个热点———构造变形 /变质精细年代学研究的现状和意义、存在的问题和难点 ,以及新技术方法及其可行性和应用等 ,目的在于提请国内同行在进行相关研究时对此能予以重视。  相似文献   

海洋激光测深技术介绍     

昌彦君  彭复员  朱光喜  杨述斌  朱耀庭 《地质科技情报》2001,20(3):91-94

介绍了机载激光海洋测深技术的原理、特点 ;简述了系统的组成和主要技术指标 ;概述了其发展历程、关键技术 ;分析了该项技术的发展趋势 ;最后对该项技术的应用前景进行了展望  相似文献