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1.
电感耦合等离子体发射光谱法同时测定玻璃中铝钙铁钾镁钠钛硫 总被引:2,自引:2,他引:0
通过选择分析谱线、处理样品方法和消除干扰因素等实验,建立了电感耦合等离子体发射光谱法同时测定玻璃中的Al2O3、CaO、Fe2O3、K2O、MgO、Na2O、TiO2和SO3的方法,克服了利用常规化学法测定玻璃中各氧化物步骤繁琐、耗时长、工作量大的不足。方法的回收率为95.0%~103.0%,精密度(RSD,n=10)为0.20%~1.72%。方法具有快速、简便、线性范围宽等优点,分析误差满足常规化学分析法的要求。用于钠钙硅玻璃及其制品的分析,结果令人满意。 相似文献
2.
指出了共线条件方程式教学中应注意的一些问题:共线条件方程式是联立的两个平面方程式,存在双主距(fx,fy)时的几何概念,以及它的变换式与直接线性变换关系式的异同点。 相似文献
3.
Introduction With rapid development and advancement of economy and society, lots of city groups or city belts with ex-tra-large cities as their centers have been formed in China. The regions these city groups lie in usually have well-developed economy, dense population, and are regional politics and culture centers. Some groups lie in the regions with high level of earthquake activity, such as the Surrounding Capital City Group with the centers of Bei-jing and Tianjin. Once a large earthqua… 相似文献
4.
采用中国中西部地区(21~36N, 98~112E)193个地震台在1992~1999年间记录到的9 988次地震的Pg和Sg震相走时的读数资料,用Roecker的SPHYPIT90程序,反演了该地区三维地壳P波速度结构,并用SPHREL3D90程序进行了地震的重新定位.反演结果揭示了中国中西部地区地震P波速度结构明显的横向不均匀性,这些不同深度上波速的横向变化多以该地区的活动断裂为分界线.可以看出活动断裂两侧存在明显的速度反差.通过重新定位,得到了6 459次地震的震源参数,这些精确定位的地震震中明显沿该区活动断裂呈现条带状分布,其范围和尺度清晰地表示了这一地区地震活动与活动断裂的紧密关系.其中,82%重新精确定位的事件的震源深度在20 km以内. 这一结果与笔者用双差地震定位法得到的重新定位的震源深度分布相一致. 相似文献
5.
IntroductionUnderstandingthemechanismofcontinentalearthquakesisveryimportantforseismichaz-ardpreventionandearthquakeprediction.Themodernseismotectonictheoryandtheideaofearthquakepredictionaredevelopedmainlyfromthestudiesoninterplateearthquakes,whicharedifficulttoexplainthephenomenaofintraplateearthquakes,suchasthecontinentalearthquakesoccurredinChinesemainland.Whiletheinterplateearthquakesoccurredalongtheplatebounda-ries,theintraplateearthquakesdistributediffuselyintheinterioroftheplates.Thus… 相似文献
6.
A New Reference Material for Tritium Organic Molecules in Sediment: Results of an International Intercomparison Exercise 下载免费PDF全文
Phillip E. Warwick Ian W. Croudace Richard M. Marsh Nicolas Baglan Sang Bog Kim 《Geostandards and Geoanalytical Research》2018,42(2):253-262
Solid matrix 3H reference materials are challenging to prepare given the volatile nature of 3H and are often unrepresentative of the range of 3H forms that may be encountered during routine analysis. As a result, few 3H reference materials are currently available, undermining verification of analytical techniques for environmental 3H measurement. To address this, an International Working Group on Organically‐Bound Tritium Analysis determined to produce a tritium natural matrix reference material (NMRM). The reference material comprises marine sediment blended with sewage sludge contaminated with 3H‐organic species arising from authorised discharges from a radiopharmaceutical manufacturing site. Previous studies have demonstrated that the 3H species have persisted in the environment over three decades providing valuable supporting data to underpin the characterisation of the NMRM. The preparation and characterisation of the NMRM are described along with the subsequent application of the reference material in an international intercomparison exercise involving nineteen laboratories from nine countries. A reference value of 168 ± 22 Bq kg?1 was derived from the data arising from the proficiency test. 相似文献
7.
叠前地震资料中包含纵波速度、横波速度、密度和吸收衰减系数等弹性及粘弹性信息,其中吸收衰减属性对储层物性及流体性质尤为敏感。本文从粘弹介质精确Zoeppritz方程出发,基于介质分解理论通过公式推导及近似,建立了包含纵波速度、横波速度、密度和吸收衰减系数的纵波反射系数特征方程,利用贝叶斯反演框架,实现了叠前纵波速度、横波速度、密度、衰减四参数同步反演。模型与实际资料反演效果均表明了该方法的可靠性。该方法较好应用于胜利油田东部海上探区的油气识别,相比于常规弹性介质流体因子,四参数同步反演方法得到的吸收衰减系数能更准确地表征油气的分布。 相似文献
8.
R. L. McKenzie W. A. Matthews Y. Kondo R. Zander Ph. Demoulin P. Fabian D. G. Murcray F. J. Murcray O. Lado-Bordowsky C. Camy-Peyret H. K. Roscoe J. A. Pyle R. D. McPeters 《Journal of Atmospheric Chemistry》1988,7(4):353-367
Column measurements of nitric oxide were made using several techniques during the MAP/GLOBUS campaign in France in September 1985. The data sets are nearly co-located and simultaneous, therefore allowing a valid intercomparison of the various measurement methods. The range of altitudes sampled differs from instrument to instrument. This complicates the comparison because the data sets are to some extent complementary. The NO distributions apparently vary significantly from day to day, and possibly over shorter timescales. Changes in dynamics may be responsible for these variations. The results from the instruments which measure in the infrared and the ultraviolet are self-consistent, and show good agreement with photochemical predictions. On 19 September, when the intercomparison was made, the profile measured by the in-situ chemiluminescent instrument differed significantly from the predicted profile, and the measured columns were generally higher. 相似文献
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10.
When all balloon-borne measurements of NO2 in the stratosphere are reviewed, the profiles show a wide spread. Measurements of the total amount in a vertical column suggest that variability should be low when only profiles measured at mid-latitudes close to equinox are selected. With this selection, the standard deviation of the profiles measured by each technique is often less than ±20%, but the mean profiles measured by each technique differ by up to a factor 2. Despite the profiles not being measured simultaneously, these differences are identical to those revealed by the simultaneous measurements of the Balloon Intercomparison Campaigns of 1982 and 1983-a comparison can be made from the historic data alone. This suggests that measurements of other gases should be similarly reviewed and appropriate selection criteria be found that reduces the standard deviations of the measurements by any one technique. The techniques can then be intercompared without new simultaneous flights. 相似文献