共查询到19条相似文献，搜索用时 406 毫秒
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自动电位滴定仪应用于测定海洋沉积物中有机碳的可行性研究 总被引：1，自引：1，他引：0
自动电位滴定仪具有操作简便、测定速度快的优势,减少了人为操作的影响,本文使用自动电位滴定仪测定海洋沉积物中有机碳的含量,并与国家标准(GB 17378.5—2007)中根据滴定过程中溶液颜色变化用肉眼判定滴定终点的方法进行了对比分析,确定通过仪器自动判断滴定终点实现准确测定的可行性。结果表明:自动电位滴定的方法检出限为0.029%,人工肉眼判定终点的方法检出限为0.086%,在滴定终点判定方面两种方法无显著性差异,但自动电位滴定仪的准确度和精密度更优,在一定程度上可代替肉眼判定滴定终点。实际应用过程中也发现,当滴定的溶液体系由于氧化还原反应、络合作用等影响因素使电位变化较为复杂时,自动电位滴定仪有可能会得到多个等当点而无法判断哪个等当点是真正的目标等当点,此时需要利用肉眼进行辅助确定。 相似文献
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自动电位滴定测定锰矿石中锰的方法研究 总被引：3，自引：3，他引：0
多批次的锰矿石锰含量滴定分析消耗大量人工,随着自动化电位滴定仪的普及,利用仪器完成容量滴定成为可能,而将手工滴定向自动电位滴定移植是当前需要解决的课题。本文建立了一套自动电位滴定仪测定锰矿石中锰含量的方法,确定了相关滴定参数和等当点识别标准。锰矿石样品采用盐酸、磷酸分解,硝酸去除碳和有机物,高氯酸氧化,形成样品溶液。自动电位滴定仪先用硫酸亚铁铵标准溶液对预先移取的重铬酸钾标准溶液和标定空白溶液分别进行氧化还原滴定,用铂复合电极指示,计算得到硫酸亚铁铵标准溶液浓度,再对样品空白溶液和样品溶液进行氧化还原滴定,得到样品锰含量,方法检测范围为5%～60%。采用本法分析国家一级标准物质,测定结果的准确度和精密度高;分析多个产地不同水平的锰矿石样品,测定结果与手工方法进行对照,经t检验无显著性差异。建立的滴定方法自动化程度高、方法稳健,适用于冶炼企业、港口商检等行业,具有推广价值。 相似文献
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《水文地质工程地质》1980,(2)
在研究上海市地面沉降工作中,测定各土层的变形动态是很重要的。以往是采用人工定期测量埋设在各土层中的分层标的相对变化。这种测量方法的缺陷是间隔时间长,测量精度和稳定性受人工操作的影响,为了提高精度,我们试制了激光自动测标仪。 该仪器为测量各分层标相对于基岩标的高程变化 相似文献
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介绍了根据HY-3型全自动显微光度测定系统以煤反射率自动测定结果确定显微煤岩组分,鉴别混煤与确定混煤比例,确定煤中活惰性组分比例等采用的数据处理技术。 相似文献
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ＨＹ－３型全自动显微光度测定系统为煤、焦、中间相、矿物等反射率提供了自动测定工具。本文介绍了其中采用的技术措施与反射率自动测定过程中采用的技术方法。 相似文献
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The problem of automatic detection of seismic waves by large telemetered seismic networks such as the Mexican Continental Aperture Seismic Network (RESMAC), is extended here to include determination of seismic first-arrival and S-phase-arrival times. A short general outline of the detection problem background and a small introduction to the autoregressive model (AR) concept are presented. Several automatic detection algorithms were implemented and compared with a newly developed autoregressive algorithm. Careful consideration of the advantages and disadvantages of each method determined that a mixed detection scheme is optimal and suitable for RESMAC. A few examples are shown that illustrate the relative performances of the methods tried here. The proposed detection scheme has the following characteristics: (a) First-arrival detection, based on a simple (average of squared input) characteristic function, and a trigger criterion that uses as a distortion measure the long-average-to-short-average ratio of the characteristic function, checked using a duration criterion; (b) use of two threshold values, one for triggering, and another for beginning the backward search for the phase arrival time; (c) use of the autoregressive model (AR) method, with the Itakura-Saito distortion measure, for S-phase detection, checked using both duration and amplitude criteria; and (d) characterization of the reliability of the determinations for their subsequent use in automatic location programs, alarms, etc. The automatic detection scheme has proved effective. 相似文献
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U. Kramar 《Geochimica et cosmochimica acta》1980,44(2):379-382
This paper deals with the disturbance of INAA trace element determinations in rocks by second order activation. The degree of error in the determination of Gd by Eu in rocks is checked by experiments and compared with results of computer evaluations. The consequence of the Dy-interference for the determination of Ho was also calculated. Hints to avoid these interferences are given. 相似文献
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Rb---Sr whole-rock and zircon U---Pb isotopic work is reported from the northern part of the region between the Mylonite and Protogine Zones in the southern Baltic Shield. Three age determinations on polymetamorphic gneissic granites were carried out. Two of these yielded U---Pb upper-intercept ages of 1650 and 1675 Ma, respectively, which is approximately one hundred Ma less than expected from the combined field evidence and earlier isotopic age determinations. Although the new discordias appear well defined, various criteria suggest that the U---Pb isotope system was disturbed. Thus, the Rb---Sr system had been opened, but nevertheless the Rb---Sr errorchrones are consistent with the U---Pb upper-intercept ages, and an abraded zircon fraction suggests an older age than the unabraded fractions. The third U---Pb age determination resulted in a poorly constrained discordia. Its upper intercept ranges between 1575 and 1605 Ma, depending on the number of fractions considered.
This paper tests a three-stage model, where the intrusion age is set identical to the 1780 Ma intrusion age of the undeformed assumed protolith. The first two analysed rocks are consistent with a model suggesting intrusion at 1780 Ma followed by partial opening of the isotopic systems early (1200 Ma) and late (950 Ma) during the Sveconorwegian orogeny. An abraded fraction together with the time of the suggested last opening of the system 950 Ma ago defines a two-point discordia with an upper-intercept age of 1745 Ma. This age is in close agreement with the assumed intrusion age. The isotope data from the third gneissic granite cannot be fitted to this simple model.
It is concluded that the analysed rocks could belong to the granitoids of the Transscandinavian Igneous Belt, but if they do, they were reworked during the Sveconorwegian orogeny. As a corollary, it follows that the regions separated by the northern part of the Protogine Zone largely had a common pre-Sveconorwegain geological history. Another important implication is that the intrusion ages in the area between the Mylonite and Protogine Zones are older than those of the Trans-Labrador Batholith in Canada. 相似文献
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微波密闭消解-等离子体质谱法测定岩石样品中的稀土元素 总被引：31，自引：14，他引：17
建立了有微波密封ＨＦ＋ＨＮＯ３消解样品,等离子体质谱测定岩石样品中１５个稀土元素的分方法。用该方法对国内外岩石标准品进行测定,结果表明稀土元素的测定值与标准值之间的相对偏差小于５％,检出限为（０．１－０．９）＊１０＾－９,多次测定结果的相对标准偏差在１．３％－５．２％。各类实际岩石样品中稀土元素的分析结果均与地质规律相符,进一步证明了方法的可靠性。 相似文献
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电感耦合等离子体发射光谱法测定钼矿石和铜矿石中的铼 总被引：3，自引：0，他引：3
采用氧化镁-硝酸钠-过氧化氢处理试样,不需分离富集,电感耦合等离子体发射光谱法直接测定钼矿石及铜矿石中的铼,筛选了不同溶矿方法和仪器参数条件。方法检出限为0.014μg/g,相对标准偏差(RSD,n=11)小于5.00%,经国家一级钼矿石及铜矿石标准物质分析验证,结果与标准值吻合。 相似文献
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有限应变测量是研究岩石变形特征的重要研究内容。为了提高岩石有限应变测量的精度与速度,改变手工测量岩石有限应变耗时、枯燥的状况,应用多重图像限制的自动种子区域生长算法,以大青山地区为例,对如变形区内的石英砂岩有限应变进行了自动测量。该算法综合多个图像、利用色彩信息,不需要特殊设备即可对颗粒进行自动识别。算法还在叠加后的图像中,应用了修改的Canny边缘检测算法增强颗粒边界与内部的对比度。识别结果与手工测量的颗粒,在质心坐标、面积、长轴、短轴、有限应变测量方面具有很大的相似性。 相似文献
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The paper compares pole figure determinations with neutron diffraction and X-ray diffraction on experimentally deformed carbonate rocks, a coarse grained marble and fine grained limestone. Neutron diffraction enables determination of complete pole figures on a single spherical specimen and is advantageous for coarse grained materials. Results obtained with both diffraction techniques agree satisfactorily, although uncertainties introduced by counting statistics are more serious for neutrons than for X-rays. Continuous detectors add new possibilities which are still little explored. 相似文献