共查询到20条相似文献，搜索用时 187 毫秒
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用倒立尺法测量水准高程辛义（广西横江水文站）测量水准高程,最怕读错数,所以校核读数是很重要的。目前常用的水准测量校核读数的方法是使用双面水准尺,虽然反面刻划是一个复式的数字作起点,在水准测量校核时有些麻烦,如把正尺读数加反尺的起点读数,才能知道读数... 相似文献
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山西大队物探队详查组 《地球科学》1958,(Z1)
一、磁秤的两次读数 以前,磁秤在一点上照例是读四次数,而在长期工作中知道,在正常的情况下,第三、四次读数和第一、二次读数相差不大,于是我们由四次读数改成了两次读数。 四次读数是为了检查仪器的同向差、和水平泡的位置。检查读数是否正确,保证测量的精度,在改为二次读数之前,我们曾作试验,证明二次读数完全能达到所要求的精度(均方 相似文献
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提高浅海重力测量观测精度的方法技术 总被引：6，自引：0，他引：6
卢景奇 《物探化探计算技术》2007,(Z1)
由于海上工作环境特殊,对于海底高精度重力测量而言,其技术条件要求较高且较复杂。这里列举了海重实测中经常遇到的几种影响海底重力仪读数精度的因素,并结合数年积累的经验,介绍了几种减小读数误差且行之有效的方法。 相似文献
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粘度是粘性液体的重要技术指标之一。对粘度的测量有很多方法，但一般都不同程度的存在着测量时间长、误差大、清洗困难、不能直接读数等缺点。本文介绍一种液体粘度快速测量方法，可直接快速测量并读出被测液体的运动粘度值。 相似文献
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JJX-3型井斜仪出厂允许误差是正负30′,但在1°以内的倾角测量中,往往出现负值。例如,仪器读数为-20′时实际斜度为30′左右。 相似文献
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使用补偿式激发电位仪,进行激发电位测量时,其观测数据的准确性,直接影响到工作质量。引起读数不准的原因:电极电位的变化、自然电场、过渡电场等因素(以下统称干扰因素)。如何正确认识这 相似文献
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BGO系列伽玛能谱仪是采用锗酸铋(BGO)晶体研制成的。具有探测灵敏度高,读数稳定,测量精确、轻便,晶体不潮解,不易碎,仪器功能全等特点。不仅适用于铀矿地区,对石油、煤田、金矿等低放射性地区也很适用。 相似文献
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超细粉末材料粒度测试技术研究 总被引：1，自引：0，他引：1
随着科学技术的发展,越来越多的细粒级粉末产品成为社会需求。如何便捷、准确地获得这些超细粉料的粒度数据,也就成了工艺矿物学工作者的一个课题。粒度测试分析中存在一些仍未解决的问题,例如采用不同的测试方法得到不同的粒度数据、取样的代表性和制样的合理性等。对于超细粉料,除了上述普通物料粒度测试中存在的问题之外,还会出现一些新问题,例如团聚现象的普遍性及其给各种测试方法带来的技术难题。近年来中国颗粒学会、国家有色金属工业局和冶金工业局等单位在这些方面做了许多有益探索,但在一些难题面前仍然显得软弱无力,主要… 相似文献
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筛法／激光粒度仪法接序测定全样泥沙粒度是泥沙粒度分析的基本方法,分级交混现象会时有出现,需要研究全样级配的调整处理。本文从先用筛分法分析全样泥沙到分界粒级,再将分界粒级以下(筛下)泥沙做全样用激光粒度分析仪法分析的作业程序,按激光粒度分析仪法小于分界粒级D_(FJ)的泥沙的质量／体积比例等于1(100％)和小于1(100％)两种可能,提出了相应的粒度分析级配序列计算调整方法和全样级配序列的接序方法。分析了以“筛法分界粒级级配为准”和“以激光粒度分析仪法最大粒级级配为准”的不足。认为激光粒度分析仪法向上粒级的分界交混质量较小,应用本文“激光粒度分析仪法分析小于分界粒级D_(FJ)的泥沙的质量／体积比例小于1(100％)”的方法和公式,调整处理分级交混问题比较合理。 相似文献
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PPP-BOTDA分布式光纤传感技术及其在试桩中应用 总被引：3，自引：1，他引：2
布里渊时域分析技术（brilliouin optical time domain analyzer, BOTDA）是近年来在国际上研发成功的一种分布式光电传感技术,该技术已开始广泛应用于结构体和工业设备等的温度、应变检测。而新一代分布式应变测量技术--脉冲预泵浦-布里渊时域分析（pulse-prepump-brilliouin optical time domain analyzer, PPP-BOTDA）,实现了10 cm的空间分辨率和±7.5 με的应变测量精度。文中重点介绍了PPP-BOTDA工作原理以及技术验证,并在国内首次将PPP-BOTDA技术应用于管桩桩身应变测量,与同时进行的滑动测微计实测数据进行对比,结果表明PPP-BOTDA可作为一种新型的桩基测试技术加以推广 相似文献
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Accurate measurements to assess the influence of soil moisture on CO2 flux requires the absolute estimates of soil CO2 flux. Thus, it was constructed a calibration system where CO2 with fixed concentration flowed through the different porous material. Previous to measurement, in order to verify the performance
and reliability of a closed dynamic chamber, different discontinuous air-mixing rates and times were tested. The CO2 flux was estimated through sequential lectures and the best fit for flux measurements was obtained taking short readings
every 3 min, during a total time of 12 min (R
2 = 0.99). The best mixing rate was attained for 250 mL min−1, allowing 25 s of mixing previous to CO2 extraction for an infrared gas analyzer. The deviation of the measured values for dry sand from the reference CO2 flux (0.097 and 0.071 g m−2 min−1) was 5 and 7%. On dry sandy loam soil (SLS) the deviation was 2%. The measured fluxes decreased 73 and 22% with content moisture
of 20 and 10% (sand), and 78% with content moisture of 31% (SLS). This work allowed to estimate how much the measured emission
rates deviate from the true ones for the specified chamber and sampling conditions. 相似文献
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中国南极考察队从2007年开始对达尔克冰川进行现场监测工作,在冰面上投设监测花杆并用前方交会的方法持续对花杆进行精确定位,用于冰川运动监测。2007-2012年,中国南极考察队员在东南极达尔克冰川上共计开展了18个批次的现场测量工作,经分析得到了67个高精度的空间交会点坐标,分属于10个独立的观测标志。为精化计算模型必须对实测数据仔细甄别,因此,同时考虑了仪器的归零差、地球曲率误差、大气折光误差等交会定位的主要误差来源,比较了3种因素对精确定位的影响,结果表明：地球曲率对精确定位的影响最大,其次是归零差,最后是大气折光引起的误差。对交会定位中各种误差的分析有利于改进同类工作中计算模型的选择,为冰川运动监测提供高精度的数据支撑。 相似文献
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A method of extraction for amino acids from soils and sediments involving superheated water has been investigated. About 75–97 per cent of the amino acids contained in four soils of a soil profile from Illinois were extracted by this method. Deep penetration of water into soil aggregates and partial hydrolysis of peptide bonds during this extraction by water at high temperature are likely mechanisms responsible for the release of amino acids from samples. This extraction method does not require subsequent desalting treatments when analyses are carried out with an ion-exchange amino acid analyzer. 相似文献
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采用淘析法、激光粒度分析法、渗透过滤法、显微镜法对膨润土及石英的粒度进行测量比较分析。实验结果表明：4种方法得到的粒度由大到小依次为淘析法、激光粒度分析法、显微镜法、渗透过滤法;由于凝聚的影响,淘析法与激光粒度分析法测试结果粒度偏大;渗透法分析结果与显微镜法结果较为接近;膨润土在水中崩解的粒度比石英要小,但采用沉降法分离提纯,膨润土比石英更易于团聚,因此在湿法提纯研究中,有必要添加分散剂。 相似文献
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Optical spectrum based measurement of flotation slurry contents 总被引：1，自引：1，他引：0
Olli Haavisto Jani Kaartinen Heikki Hytyniemi 《International Journal of Mineral Processing》2008,88(3-4):80-88
Monitoring and control of a flotation circuit is mainly based on the information gained by assaying the process slurry lines. In flotation plants, usually an X-ray fluorescence analyzer is used to obtain the on-line assays. This article introduces the visual and near-infrared reflectance spectroscopic analysis of the process slurries as a supplementary method which complements the on-line assay information available from an X-ray fluorescence analyzer. It is shown that the spectral information can be used to accurately predict the element contents in the slurry in between successive XRF analyses. Since the spectral measurements can be taken with high frequency as opposed to the sparse X-ray fluorescence analysis, a practically continuous on-line estimate of the slurry contents is reached. These estimates can be used in the plant control to improve the overall performance of the circuits and to yield also economical savings. Additionally, the frequent monitoring of the grades can provide means to eliminate rapid disturbances in the circuits, thus improving the stability of the process. 相似文献
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This article introduces an interdisciplinary collaboration that brings together sympathetic trends in qualitative geographic visualization (from the perspective of one author who is a geographer) and contemporary generative artistic practices (from the perspective of the other author, who is an artist and theorist)—attempting to represent a diverse array of creative and multi-modal data through generative and participatory digital methods. We present how this convergence expands categories of meaning, allowing us to explore experiential/embodied as well as creative/imaginative engagements with everyday geographies distinct to a digital age. The article mediates on the idea of mapping the imagination and the ways we imagine quotidian spaces, as well as possibilities for new methods for the analysis and representation of spatial and emotional complexity. We particularly explore strategies of integrating multiple technologies and multiple-modes of representation for mapping and re-mapping complexities of social and creative living in order to help provide alternate ways to imagine, represent and engage different forms of embodied and imaginative geographies. This article presents a case study with the artist Andrew Buckles, in Seattle, Washington, correlating representational and participatory digital data including geospatial, temporal, audio, video as well as electroencephalography readings from brainwave sensors. 相似文献