Application of AMD to the Determination of Cropprotection Agents in Drinking Water. Part III: Solid Phase Extraction and Affecting Factors Anwendung der AMD-Technik zur Bestimmung von Pflanzenbehandlungsmittel-Wirkstoffen im Trinkwasser. Teil III: Festphasenextraktion und ihre Einflußfaktoren     

G. Pfaab  H. Jork 《洁净——土壤、空气、水》1994,22(5):216-223

The more sensitive an analysis method the more care must be given to sample preparation. Solid phase extraction (SPE) onto RP 18 phases has established itself as a general purification and enrichment technique for trace components in aqueous samples. Various factors may thereby influence the recovery rate. For example, the ratio amount of sorbent and sample volume should be taken into account to avoid breakthrough of the investigated substance. Extracting phenylurea herbicides from drinking water, the ratio should be 1 g RP 18 sorbent per 1 L water sample. Concerning the flow rate for the fungicides procymidone, vinclozolin, and iprodione, the recovery rate decreases using higher flow rates than 3 or 6 mL/min. In the case of phenylurea herbicides, a flow rate of 10 or 14 mL/min showed best results. Even the coefficient of variation is below ± 5% at these flow rates. Furthermore, the company dependence should be considered because the recovery rate might differ by up to 40% using the nominally identical material. The same applies to the batch dependence of quality from the same company. The concentration of the eluate must also be monitored and carried out with great care to avoid decreasing the recovery rate. Considering these factors of influence, SPE is a very useful tool in sample preparation, particularly if an automated system is used.  相似文献   

深井水位固体潮的调和分析结果   总被引：2，自引：0，他引：2       下载免费PDF全文

郑香媛  刘澜波 《地球物理学报》1990,33(5):556-565

使用Venedikov调和分析方法,对8口深井各一年或两年经气压改正后的水位记录,计算了水位固体潮相对于体应变固体潮的振幅比和相位差。本文从相位差的分析结果求解了含水层的渗透率,分析结果还显示出液态地核动力学效应引起的固体潮日波振幅比的共振现象。这是对以往其它观测手段得到的相应结果的支持,同时也说明了深井水位资料中含有非常丰富的地球物理信息。文中还对环境因素和井孔条件造成的某些效应做了探讨。  相似文献   

大化水库地震分析     

光耀华 《华南地震》1990,10(4):71-75

大化水库自1983年蓄水后出现频繁的微弱地震,延续时间达7年,最大震为Ms1.7级,地震系列属震群型,初步判断属水库诱发地震。由于库区有活动断层且岩溶发育,地震诱发机制可能为断层孔隙水压力效应或岩液塌陷。从地震发展趋势分析,目前已处于衰减程过,预测今后不会有强震发生。  相似文献   

Complete synthetic seismograms for high-frequency multimodeSH-waves     

N. Florsch  D. Fäh  P. Suhadolc  G. F. Panza 《Pure and Applied Geophysics》1991,136(4):529-560

We present an efficient scheme to compute high-frequency seismograms (up to 10 Hz) forSH-waves in a horizontally stratified medium with the mode summation method. The formalism which permits the computation of eigenvalues, eigenfunctions and related integral quantities is discussed in detail. Anelasticity is included in the model by using the variational method. Phase velocity, group velocity, energy integral and attenuation spectra of a structure enable the computation of complete strong motion seismograms, which are the basic tool for the interpretation of near-source broad-band data.Different examples computed for continental structures are discussed, where one example is the comparison between the observed transversal displacement recorded at station IVC for the November 4, Brawley 1976 earthquake and synthetic signals. In the case of a magnitudeM _L =5.7 earthquake in the Friuli seismic area we apply the mode summation method to infer from waveform modeling of all three components of motion of observed data some characteristics of the source.On leave from Institute of Geophysics, ETH, Zürich, Switzerland.  相似文献   

遥感技术的经济效益分析模型与计算方法     

阎守邕 《遥感学报》1991,(1)

本文在遥感技术系统分析的基础上,给出了一个效益分析模型与相应的一些计算方法。在找寻提高遥感效益关键所在及制定遥感发展战略、政策和规划的过程中,它们是一个非常有效的工具。  相似文献   

深部气层和干层测井模糊综合评判     

胡云昌  师先进 《上海国土资源》1995,(2)

深部气层和干层的区分是常规测井解释的难题。认识始于实践。本文依据东濮凹陷深层试采资料,建立了两个模式各四个参数的隶属度曲线,进行气层和干层模糊综合评判研究,并用该地区深层试井资料作了检验,效果颇佳。证明模糊综合评判是区分深部气层和干层的一种行之有效的方法。  相似文献   

基于奇异谱分析的南方涛动指数短期气候预测试验   总被引：2，自引：0，他引：2  

Liu Jianwen  Dong Peiming 《大气科学进展》2001,18(5):873-881

The Southern Oscillation Index (SOI) time series is analyzed by means of the singular spectrum analysis (SSA) method with 60-month window length. Two major oscillatory pairs are found in the series whose pe riods are quasi-four and quasi-two years respectively. The auto-regressive model, which is developed on the basis of the Maximum Entropy Spectrum Analy sis, is fitted to each of the 9 leading components including the oscillatory pairs. The prediction of SOI with the 36-month lead is obtained from the reconstruction of these extrapolated series. Correlation coefficient between predicted series and 5 months running mean of observed series is up to 0.8. The model can successfully predict the peak and duration of the strong ENSO event from 1997 to 1998. It＇s also shown that the proper choice of reconstructed components is the key to improve the model prediction.  相似文献   

位场小波分析的物理解释   总被引：13，自引：3，他引：10       下载免费PDF全文

梁锦文 《地球物理学报》2001,44(6):865-870

采用二进小波变换,构造了位场基小波,通过简单模型,分析了位场信号小波分解与重构的物理实质,阐明了小波变换的频带分布与“归一化”位场空间分布的一致性,以及小波重构的规律,并叙述了小波重构与异常分解的关系.  相似文献   

Analysis of Physical and Chemical Parameters for Discrimination of Water Origin in a Hydroelectric Reservoir     

Wagner José Barreto  Ieda Scarminio  Maria Cristina Solci  Dílson Norio Ishikawa  Melissa Tiemi Ogasawara  Sônia Naomi Nomi  Sônia Regina Giancoli Barreto 《洁净——土壤、空气、水》2007,35(3):239-245

Seventeen physical and chemical parameters were obtained from a hydroelectric reservoir located in a tropical region in the south of Brazil. Multivariate Principal Component Analysis (PCA) and Hierarchical Group Analysis (HGA) were used to identify the parameters discriminating the origin of water from the Tibagi and the Primeiro de Maio River, after it has passed the mixing region. The study was conducted during the dry and rainy seasons in July 2002 and February 2003 at three depths and three sampling sites located 0, 5, and 10 km away from the mixing region. The statistical methods showed to be appropriate for identifying the contribution of each tributary in the water mixing site of a complex water system. The most important discriminating parameter was the absorbance relation A(253 nm)/A(203 nm), followed by the concentrations of Fe(III), Mn(III), and Ni(II). An anthropogenic interference was found in the reservoir due to high Ni(II) and orthophosphate concentrations caused by a nearby town sewage discharge. The interference was more important during the dry periods due to the lower dispersion of the pollutants. Urgent initiatives should be taken from the state government to build treatment stations for the wastewater of the small cities around the Capivara hydroelectric reservoir to prevent the drinking water quality from deteriorating.  相似文献   

中子活化分析在公路交通燧洞水文地质调查中的应用   总被引：1，自引：0，他引：1  

侯新生  贾疏源  王永利  虞修竞  唐光洁  于静 《物探与化探》2002,26(4):293-295

利用中子活化测试结果 ,对岩石及泉水干涸残余物中常量及微量元素的进行分析对比 ,以了解深层岩体有关的地质与水文地质信息  相似文献