共查询到19条相似文献，搜索用时 125 毫秒
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联用筛析法与激光法进行粒度接序分析的界点选择 总被引：1，自引：0，他引：1
筛析法、激光法和图像法是三种常用的粒度分析方法,但由于测试原理的不同,三种测试方法有不同的适用性。筛析法和图像法能够精确测量砂质颗粒的粒径,但不适用于泥质细颗粒（<0.063 mm）的粒径测量;相反,激光法无法准确测量中粗砂粒级颗粒（2~0.21 mm）,但能高精度测量较细沉积物粒径。分选较差的天然沉积物粒径分布范围较广,需要综合运用筛析法-激光法进行接序粒度测试。通常选用2 mm为界点开展接序粒度分析,但因激光法在测量中粗砂颗粒时误差较大,易导致接序粒度分析结果准确性不高。建议以0.21 mm为分界点开展接序粒度分析,分别避开筛析法和激光法测量精度不高的粒级区间,可使测试结果的准确性得到有效的提高。 相似文献
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《地壳构造与地壳应力文集》2014,(0)
分析沉积物的粒度组成是沉积环境和古地理研究的重要内容。作为粒度分析标准方法的图像法,其发展和应用一度受制于耗时长和样本量较小等实际困难。目前,新的动态图像法粒度粒形获取技术可在几分钟内获取10~7~10~8个颗粒的大小和形状,为图像法的广泛应用提供了新的机会。本文对采自河流和湖滩的共34个松散砂样分别用图像法和激光衍射法进行了粒度测试和对比,分别就图像法测试所需的最少样本量及图像法和激光衍射法粒度测试结果的差异进行了探讨。通过改变样本量大小观察粒度参数计算结果的变化,认为河流和湖滩砂样最小样本量不少于30000和10000时,测试结果基本能代表完整样品的粒度分布(均值粒径标准偏差≤0.015)。通过比较图像法和激光衍射法测试结果中各粒级含量和粒度参数的差异,认为两种方法对粉砂级的测试结果有很大差异,无可对比性;对细砂级、中砂级和粗砂级的测试结果相关关系显著。两种方法得到的均值粒径有很好的相关性,可以互相转换,分选系数、偏度和峰态的相关性弱,无可比性。本文的研究结果可为图像法的应用提供一定的参考。 相似文献
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文章回顾了粒度分析的历史,总结了常用的粒径类型,介绍了粒度标准和目前沉积学中常用的5种粒度分析方法,并对其中的沉降法、场干扰分析法、图像法作了详细的分类说明。此外,对每一种粒度分析方法的适用范围、测定原理以及其存在的优缺点也进行了详细的介绍。其中：直接测量法简单易行,但精度较差;筛析法较为普遍,但只限于松散或弱胶结沉积物,且不能反映颗粒形状;沉降法适用于松散样、弱胶结样和液体样的分析,可对细砂、粉砂或泥等细粒沉积物进行测量;场干扰法主要依据碎屑颗粒的衍射、散射及电压脉冲响应进行,固体样和液体样均可,精度高,适用性广;图像法手段多样,简单直观,操作性强。总体上,未来的几十年内,粒度分析方法仍将是新旧技术并存,多种方法共用的状况。 相似文献
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沉积物粒度分析方法的比较 总被引：5，自引：0，他引：5
近年来激光粒度分析法在沉积物粒度分析方面的应用得到了进一步扩展。本文利用美国麦克奇公司生产的S3500型激光粒度分析仪开展沉积物粒度分析方法实验,研究表明:S3500型仪器较优的样品用量约为0.2 g;稀释过程会影响样品的粒度分布;样品分取方式会带来不同的随机误差。与薄片图像法和筛析法两种传统粒度分析方法获得的粒度分布参数比较表明:激光法测得的平均粒径较薄片图像法和筛析法偏细;激光法和筛析法的峰度相关性较好。采用Malvern 2000和Micro S3500两种激光粒度分析仪测量结果的比较表明:Malvern 2000测得的平均粒径较Micro S3500测得的平均粒径偏细,但二者的相关性很好(r=0.9574),研究认为这两种粒度仪的测试结果会给岩石粒度定名带来差异。由于各种粒度分析方法存在差异和局限性,在实际工作中粒度分析应尽可能建立在同一测量体系上,以便资料对比。 相似文献
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动态图像法应用于海滩沉积物粒度粒形测试及其与筛析法的比较 总被引：1，自引：0，他引：1
筛析法是海滩沉积物粒度分析较经典和常用的方法。随着科学技术的发展,利用动态图像法分析沉积物粒度逐渐得到推广。本文利用动态图形法和筛析法对海南岛5个海滩剖面20组沉积物样品进行粒度粒形测试,并将两种方法所测得的粒度进行比较。测试分析结果显示,该方法的测试结果重复性好,精度高;通过与筛析法的对比显示,动态图像法与筛析法的测试结果非常接近,粒度级配曲线基本一致,各个粒度参数值很接近且相关性非常好（R2>0.94）;由动态图像法得出的粒形参数可以看出,粒径相当的不同海滩沉积物粒形参数有很大差别,同一海滩不同部位的球形度和宽长比变化很大,对称度和凹凸度变化稍小。研究表明,动态图像法与筛析法之间的粒度分析差异主要来自于两者测量原理的不同和天然海滩砂颗粒形状的不规则;动态图像法解决了不规则沉积物粒度的测量。因此,动态图像法可以替代筛析法来测量沉积物粒度,应用前景广阔。 相似文献
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利用自行设计开发的显微图像分析系统进行矿物粒度分析，将其结果与用水析、激光粒度分析、筛分分析所得结果进行对比，分析讨论产生数据差异的原因。 相似文献
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以新型快速成像及处理技术为基础的动态图像法可为单个样品快速建立百万至上亿个颗粒的图像及粒度、粒形参数数据库,可直观表现天然沉积物的海量颗粒的大小和形状信息,但目前对其与激光法测试结果之间的异同尚缺乏深入理解。本文对采自山东半岛黄岛地区黄海沿岸3处海滩共190个样品进行动态图像粒度分析,通过等效投影面积径(等积径)计算均值粒径、分选系数、偏度、峰度等粒度参数,并与激光法测试结果进行对比。结果表明:1)现代海滩沉积物图像法统计粒径比激光法稍粗,但二者之间的差异较之细粒沉积物较多的类型(如冲洪积物)而言已经很小;2)现代海滩沉积物图像法粒度分析较之激光法分选更优,偏度和峰度均更小;3)图像法和激光法粒度分析结果在沉积环境判别中具有相近的功能,但图像法对沉积环境和动力条件的响应更为敏感。这些认识为动态图像粒度分析技术的应用推广和资料解释提供了新的理论与技术支持。 相似文献
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The autocorrelation technique for estimating grain-size from digital images of sand beds has been extended and validated for use on coarse sand (0·7 mm) and gravel (up to ∼20 mm). A number of aspects of the technique have been explored and some potential improvements suggested. Autocorrelation is just one suitable statistical method sensitive to the grain-size of sediment in digital images; four additional techniques are presented and their relative merits discussed. A collective suite of techniques applicable to the general problem of grain-size estimation from digital images of sediment might broaden the applicability to more sedimentary environments, as well as improve its accuracy. These techniques are compared using a large data set from a gravel barrier beach in southern England. Based on over 180 samples, mean grain-size of sieved and imaged sediments correspond to within between 8% and 16%. Some theoretical aspects of the spatial arrangement of image intensity in digital images of natural sediments are addressed, including the fractal nature of sediments in images, which has potential implications for derivation of grain-size distributions from images of sand-sized material through segmentation and thresholding. The methods outlined in this contribution may also find application in further uncovering the geometric structure of sediment beds, as well as in the simulation of sedimentation processes. 相似文献
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北京地区重磁数据计算机图像处理及地质效果 总被引：2，自引：1，他引：1
介绍了对北京地区重力和磁力数据进行计算机图像处理的技术及流程,解译了重磁数据图像处理结果,分析了重磁数据计算机图像处理的地质效果,得到了一些对北京地区成矿预测有益的新认识 相似文献
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An oblique factor analysis solution for the analysis of mixtures 总被引：2，自引：0，他引：2
Thomas L. Clarke 《Mathematical Geology》1978,10(2):225-241
The problems involved in the factor analysis of data consisting of measurements of material quantity or proportion are discussed, and the inability of existing factor analysis solutions to properly model such data is pointed out. A new factor analysis solution using the linear programming technique is presented which properly analyzes mixture data. A numerical example is presented in which a body of suspended sediment grain-size distribution data is analyzed using the new factor analysis solution. FORTRAN-IV subroutines for computing this solution are included in an Appendix. 相似文献
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A refined wet sieving method for the analysis of nonlithified oceanic and marine sediments is suggested based on comparison of the Petelin (SIO, Russia) and Atterberg (AWI, Germany) methods, which makes it possible to accelerate the gathering and processing of grain-size data and significantly improve the convergence between results obtained in Russian and foreign laboratories. 相似文献
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Genetically meaningful decomposition (unmixing) of sediment grain-size distributions is accomplished with the end-member modelling algorithm. Unmixing of the loess grain-size distributions of a Late Quaternary loess–palaeosol succession from the north-eastern Tibetan Plateau indicates that the loess is a mixture of three end-members representing very fine sandy, coarse silty and medium silty loess. The unmixing approach potentially enables the unravelling of sediment fluxes from multiple dust sources, opening the way to significant advances in palaeoclimatic reconstructions from loess grain-size distribution data. However, as laser-diffraction size analysis is a volume-based technique, the proportional contributions of the modelled end-members might deviate (significantly) from weight proportions. Hence, calibration of the end-member volume proportions to weight proportions must be established before one can calculate the source-specific dust fluxes. This paper reports the findings of a sediment-mixing experiment which enables calibration of the modelled mixing patterns established for the Tibetan loess–palaeosol succession. 相似文献
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遥感和多源地学数据图像处理技术及在地质找矿中的应用 总被引：1，自引：0，他引：1
图像处理技术用于遥感、物探、化探、地质、矿产和地理等多种数据的综合处理具有广阔的前景。它灵活、方便，可快速、直观、定量地从综合信息中发现和提取那些用常规方法难于获取的地质矿产信息，以便科学地进行基础地质研究和矿产资源综合评价。本文介绍了用图像处理技术在Ｉ２Ｓ／１０１大型数字图像处理系统中处理多源地学数据的方法及优越性。 相似文献
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动态图像法、镜下测量法在地下沉积岩粒度分析中的应用研究较为薄弱。对塔里木轮南地区X100井三叠系水下分流河道12块砂岩样品分别采用以上两种方法进行粒度测试,将所测得的各组分含量、粒度曲线及粒度参数进行对比分析,并对镜下测量法粒度结果开展校正研究,以使这两种方法在今后能更广泛地运用于粒度分析。研究结果表明:相较于镜下测量法,动态图像法检测粗组分含量偏大而细组分含量偏小,黏土—粉砂组分和中砂组分是两种方法产生差异的分界线。检测颗粒数目的悬殊和岩石类型是两种方法存在差异的主要原因,测试方法的量程、测量原理和颗粒形状也会造成一定的影响。基于岩性的镜下测量法粒度结果校正,使两种方法的细砂—粗砂组分含量、粒径参数的相关系数从0.25~0.80提高到0.88~0.95,达到了校正基本目的,其准确性得到有效的提高。 相似文献
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Image analysis of aggregates does not measure the same size as sieve analysis. The size of aggregates, determined by sieve analysis, is presented with respect to the percent cumulative mass, whereas image analysis does not measure mass. Results are often presented in percent particles or percent area. Several researchers have claimed that more accurate volume and mass determinations are necessary for accurate construction of grain-size curves. In the present work, several methods for reconstructing volume and thus mass of aggregates from image analysis (IA) have been tested to see how they influence the grain-size distribution curves. The actual mass of the individual particles was found to have little or no influence on the grain-size distribution curve, which is normalized and thus insensitive to mass. Accurate conversion of image-analysis size to sieve size is dependent upon how particles pass through sieves. Most existing methods base their conversion of image-analysis size to sieve size on the intermediate axis, multiplied by some factor. The present work shows that there is no direct correlation between the intermediate axes and sieve size. A universal conversion of image-analysis size to sieve size has been developed, using the minimum-bounding square around the minimum projected area. This measure yields very good correlation with sieve-analysis results. 相似文献