共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
研究了用BaCl2沉淀分离SO^-4,消除大量硫酸盐对Sr的干扰,以实现饮用天然矿泉水中Sr的火焰原子吸收测定。水样测定相对标准偏差6.70%,加标回收率97-104%。 相似文献
3.
4.
5.
6.
西藏锑矿中金和锑的测定方法研究 总被引:4,自引:0,他引:4
西藏锑矿资源丰富,该矿的复杂性(含硫高,锑金共生)以及地理条件的特殊性,使得我们在分析金和高含量锑 的时候存在两个问题:首先是对测定锑的影响,其次是锑的干扰造成金测定结果不准确。本文采用王水溶矿,柠檬酸防止锑挥发及水解,氯化钡消除硫干扰,原子吸收分光光度法测定高含量锑,线性范围为0.xx-xx,xx%。根据锑量加入适量氯化铵,能有效消除锑对金的干扰,从而准确测定金;采用氢醌容量法可准确测定0.1-200μg/g的金;原子吸收分光光度法可以准确测定0.05-30μg/g的金。 相似文献
7.
原子吸收分光光度法测定肉类样品中微量的铜铅锌镉 总被引:1,自引:0,他引:1
采用原子吸收法对肉类样品微量铜铅锌镉进行测定,重点对样品的前处理进行实验,拟讶测试操作规程和仪器测量最佳条件,实验证明本法操作简便,准确快速,结果满意。 相似文献
8.
9.
在2.0%HCl及加入少量饱和溴水的条件下,用泡沫塑料吸附富集金。用1.0%硫脲溶液热浸提取金,然后用涂层石墨管和平台,无火焰原子吸收分光光度计测定天然水中痕量金的含量。该方法简单、可靠。 相似文献
10.
原子吸收分光光度法测定锌精矿中锌 总被引:3,自引:0,他引:3
选择Zn的非灵敏线,采用原子吸收分光光度法测定锌精矿中高含量锌。共存离子互不干扰,平均回收率为99.82%,对于锌精矿测定5次,其RSD〈0.5%,该法所测结果与国家标准分析方法测定的结果相符,且较标准分析方法简便,快速,实用性强。 相似文献
11.
12.
用NMR法验证在冻土中TDR标定曲线的可靠性 总被引:2,自引:1,他引:2
TDR技术是一种较新的测定冻土中未冻水含量的方法, 它有很多优点, 但是由于TDR技术应用于冻土中测定未冻水含量起步较晚, 其可靠性有待于进一步验证. NMR技术是一种较成熟的测定冻土中未冻水含量的方法. 通过应用NMR和TDR两种方法对不同初始含水率下的棕壤土冻融特征曲线的测定, 对TDR法的标定曲线的可靠性进行了验证. 结果表明: 采用TDR法与NMR法测得的冻融特征曲线明显不同, 在相同负温下前者的测定值高于后者, 且其差异随初始含水率增高而加大; NMR法的测定结果表明, 初始含水率对冻融特征曲线的影响很小; 而TDR法的测定结果表明, 由TDR法测得的冻融特征曲线, 受初始含水率影响很大, 随初始含水率的升高而明显加大. 这表明含冰率和温度对冻土的介电常数影响很大, 因此, 采用TDR法测定冻土的未冻水含量时不宜采用原有的标定曲线. 相似文献
13.
土壤水分传感器在现场安装后,需要针对现场土壤状况对其进行率定,以便校准率定关系。在工程实践中,土壤水分传感器现场率定是一项步骤繁杂、操作要求高、现场取土难度大、耗时较长的一项工作,严重困扰工程项目的实施。开展基于原状土柱率定土壤水分传感器研究,通过现场采集原状土柱,在实验室浸泡至饱和后取出,让土壤水分自然散失,用称重法定期称量原状土柱重量,同时记录土壤水分传感器原始测量值,以此来研究土壤水分传感器的工程率定问题,探讨提高现场安装的土壤水分传感器率定效率的方法,具有现实意义。 相似文献
14.
Chen Jiawei Bao Zhengyu Mei YupingFaculty of Earth Sciences China University of Geosciences Wuhan 《中国地质大学学报(英文版)》2001,12(3)
Heateffectoccursinmanyphysicalandchemicalreactionprocessesinnature .Measuringtheheataccuratelyinviewofenergyisafundamentaltoolforstudyingphysicalandchemicalreactionsystem .Calorimeterisadirectapproachtoheatmea surements.Basedonthis ,wecanexplorematerialt… 相似文献
15.
国内外转子式流速仪检定方法分析 总被引:4,自引:0,他引:4
国内外转子式流速仪的检定原理、方法、设备差别不大,也都基本符合国际标准。西方先进国家对具体检定方法、检定成果表达形式、检定误差表示方法等方面考虑比较完善,有利于实际测速应用和测得数据的误差评估。国内流速仪检定方法有必要在上述有关方面进行相应修订,以完善转子式流速仪的计量性能,有利于水资源水量计量的准确性评价。 相似文献
16.
Approximate but accurate, simple invertible equations for the consolidation curves under triangular excess pore-water pressures
are developed. These approximations can be used to calculate the degree of consolidation corresponding to a specified time
factor (explicit) or the time factor corresponding to a specified degree of consolidation (implicit). Explicit equations are
also developed for estimating the consolidation coefficient and final settlement, from two settlement readings, using the
proposed approximations. 相似文献
17.
In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites’ thermal infrared channels, China Radiometric Calibration Sites (CRCS) were established and the accuracy of the CRCS in-orbit field absolute radiometric calibration methods (FCM) for thermal infrared channels (TIR) was evaluated and analyzed based on TERRA/AQUA MODIS observations. Comparisons between the MODIS at pupil brightness temperatures (BTs) and the simulated BTs at the top of atmosphere using radiative transfer model (RTM) based on field measurements showed that the accuracy of the current in-orbit field absolute radiometric calibration methods was better than 1.0K (@ 300K) in thermal infrared channels. Therefore, the current CRCS field calibration method for TIR channels applied to Chinese meteorological satellites was with favorable calibration accuracy: for 10.5~11.5 μm channel was better than 0.747 K and for 11.5~12.5 μm channel was better than 0.851 K. 相似文献
18.
We present a novel approach for calibration of stochastic discontinuity network parameters based on genetic algorithms (GAs). To validate the approach, examples of application of the method to cases with known parameters of the original Poisson discontinuity network are presented. Parameters of the model are encoded as chromosomes using a binary representation, and such chromosomes evolve as successive generations of a randomly generated initial population, subjected to GA operations of selection, crossover and mutation. Such back-calculated parameters are employed to make assessments about the inference capabilities of the model using different objective functions with different probabilities of crossover and mutation. Results show that the predictive capabilities of GAs significantly depend on the type of objective function considered; and they also show that the calibration capabilities of the genetic algorithm can be acceptable for practical engineering applications, since in most cases they can be expected to provide parameter estimates with relatively small errors for those parameters of the network (such as intensity and mean size of discontinuities) that have the strongest influence on many engineering applications. 相似文献
19.
20.
针对概念性水文模型参数众多、相互制约,且多目标参数优化率定最优参数求解困难、易受决策者主观因素影响的问题,采用多目标优化算法对水文模型参数进行率定,得到模型参数最优非劣解集,在此基础上,引入最小最大后悔值决策理论,并结合Pareto支配基本理论,提出了一种多目标最优非劣解选取准则。以柘溪流域为研究对象,采用三目标MOSCDE优化率定新安江模型的参数,并与单目标SCE-UA优化结果进行对比分析。结果表明,提出的非劣解选取方法可以有效从大规模非劣解集中筛选出最优非劣解,大大缩短参数率定耗时。 相似文献