三元体系RECl_3（RE＝Dy，Yb）－HOAc－H_2O（30℃）的研究     

李亚红  王惠  王林溪 《盐湖研究》1996,(Z1)

测定了三元体系ＲＥＣｌ３（ＲＥ＝Ｄｙ，Ｙｂ）－ＨＯＡｃ－Ｈ２Ｏ（３０℃）的平衡态的溶度数据并绘制了相应的溶度图。在两个体系中分别得到了ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ两种固相。依据ＨＯＡｃ对ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ有盐抗作用这一结论得到了一种制备ＤｙＣｌ３·６Ｈ２Ｏ和ＹｂＣｌ３·６Ｈ２Ｏ的ＨＣｌ—ＨＯＡｃ法。同时，在分析测定酸的重量百分浓度时，利用“差减法”得到了Ｈ＋的准确含量。  相似文献   

WINDOW FACTOR ANALYSIS:THEORETICAL DERIVATION AND APPLICATION TO FLOW INJECTION ANALYSIS DATA   总被引：1，自引：0，他引：1  

EDMUND R.MALINOWSKI 《地理学报(英文版)》1992,(1)

Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid.  相似文献   

Biomass Burning in Southern Africa: Individual Particle Characterization of Atmospheric Aerosols and Savanna Fire Samples   总被引：2，自引：0，他引：2  

Xiande Liu  Piet Van Espen  Freddy Adams  Jan Cafmeyer  Willy Maenhaut 《Journal of Atmospheric Chemistry》2000,36(2):135-155

Ambient atmospheric aerosols and savanna fireparticulate emission samples from southern Africa werecharacterised in terms of particle classes and theirnumber abundance by electron probe X-ray microanalysis(EPXMA). About ten particle classes were identifiedfor each sample. The major classes werealuminosilicates and sea salts for ambient coarse(2–10 m equivalent aerodynamic diameter (EAD))samples, and K-S and S-only particles for ambient fine(<2 m EAD) samples. The K-S particles are oneof the major products of biomass burning. The EPXMAresults were found to be consistent with the resultsfrom bulk analyses on a sample by sample basis. Forsavanna fire fine samples, quantitative EPXMA revealedthat many particles had a composition of simple saltssuch as KCl. Some particles had a deviatingcomposition in the sense that more ionic species wereinvolved in sustaining the balance between cations andanions, and they were composite or mixed salts.Because of extensive processing during the atmospherictransport, the composition of the K-S particles in theambient samples was different from K₂SO₄,and such particles were enriched with S. The finepyrogenic KCl particles and the fine sea-saltparticles were much depleted in chlorine.  相似文献   

离子色谱法测定五氧化二铌和五氧化二钽中痕量氟氯和硫酸根离子的前处理方法     

刘肖 滕曼蔡亚岐  牟世芬 《岩矿测试》2006,25(4):319-322

采用马弗炉将样品与NaOH混合进行熔融煅烧，热去离子水提取、离心、稀释后过OnGuard Ⅱ H柱和过滤膜进行前处理，抑制型电导离子色谱法检测，测定了Ta2O5和Nb2O5的氟离子、氯离子和硫酸根离子。该方法对三种被测阴离子的检测限（s／N=3）在0．15～0．70μg／g（以固体样品实际浓度计）或0．136～0．623μg／L（以溶液浓度计），标准曲线线性范围均在两个数量级以上，方法的精密度（RSD，n=7）小于5．46％，回收率为88％～106％，具有灵敏度高、选择性好、重现性佳、对环境友好等特点，用于实际样品的检测，结果令人满意。  相似文献   

探头不同耦合方式AE法岩石应力测量效果比较     

丁原辰 《地球物理学进展》1998,13(3):67-73

以凯瑟效应测量岩石试样先存应力,声发射探头与试样的耦合是不共重要环节,国内外学者采用的耦合方法,归结起来主要是面耦合与线耦合两种方式,作者以同一试样作了这两种耦合方法的对比实验,证实地耦合的测量效果优于面耦合,作者指出：使用圆柱状试样不仅制作简便,节省制作费用,而且由于探头与试样作线耦合获得更高的测量精度。  相似文献   

Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan   总被引：4，自引：0，他引：4  

Cheh-Shyh Ting  Tienfuan Kerh  Chiu-Jung Liao 《Hydrogeology Journal》1998,6(2):282-292

 Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically. Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve the accuracy of future groundwater-simulation and management models in the plain. Received, April 1996 Revised, March 1997, November 1997 Accepted, March 1998  相似文献   

利用不完全Cholesky共轭梯度法求解点源三维地电场   总被引：30，自引：7，他引：23       下载免费PDF全文

吴小平  徐果明 《地球物理学报》1998,41(6):848-855

点源三维地电场的求解是一大型数值计算问题．本文用有限差分方法求解,最后形成一个线性方程组Ax＝b,这里A是大型稀疏的带状对称矩阵．解大型稀疏方程组的完全Cholesky分解直接算法,一般要求巨大的机器内存来存储系数矩阵A,而且计算速度极慢．因此引入不完全Cholesky共轭梯度（ICCG）算法及按行索引的稀疏存储模式,充分利用A的稀疏性,使得计算速度大大提高,而内存要求则大大减少,因此ICCG算法是地电三维正演的强有力工具．  相似文献   

Modelling the chloride signal at Plynlimon,Wales, using a modified dynamic TOPMODEL incorporating conservative chemical mixing (with uncertainty)     

T. Page  K. J. Beven  Jim Freer  Colin Neal 《水文研究》2007,21(3):292-307

The application of a modified version of dynamic TOPMODEL for two subcatchments at Plynlimon, Wales is described. Conservative chemical mixing within mobile and immobile stores has been added to the hydrological model in an attempt to simulate observed stream chloride concentrations. The model was not fully able to simulate the observed behaviour, in particular the short‐ to medium‐term dynamics. One of the primary problems highlighted by the study was the representation of dry deposition and cloud‐droplet‐deposited chloride, which formed a significant part of the long‐term chloride mass budget. Equifinality of parameter sets inhibited the ability to determine the effective catchment mixing volumes and coefficients or the most likely partition between occult mass inputs and chloride mass inputs determined by catchment immobile‐store antecedent conditions. Some success was achieved, in as much as some aspects of the dynamic behaviour of the signal were satisfactorily simulated, although spectral analysis showed that the model could not fully reproduce the 1/f power spectra of observed stream chloride concentrations with its implications of a wide distribution of residence times for water in the catchment. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Effect of Fly Ash on Frost-Resistance and Chloride Ions Diffusion Properties of Marine Concrete     

杨文武  钱觉时  章一颖 《中国海洋工程》2009,23(2):367-377

It is necessary to pay more attention to the durability of concrete undergoing freeze-thaw cycles and seawater attack simultaneously.Investigated are the effects of water-binder ratio,fly ash (FA) contents and air-entraining agent on resistance to frost and chloride diffusion of marine concrete blended with FA in natural seawater.The results show that fly ash does not improve the frost resistance of concrete but can improve its resistance to chloride diffusion by addition of less than 30%.The resistance to frost and chloride diffusion of FA concrete can be improved with the decrease of water-binder ratio,and FA may improve both of them simultaneously only being mixed with air-entraining agent.A ratio (named as R) of the frost-resisting durability factor to chloride diffusion coefficient can be used to evaluate the durability of marine concrete.Scanning electron microscope (SEM) analyses are consistent with the evaluations by the value of R.  相似文献   

High chloride concentrations in the soil and groundwater under an oak hedge in the West of France: an indicator of evapotranspiration and water movement     

C. Grimaldi  Z. Thomas  M. Fossey  Y. Fauvel  P. Merot 《水文研究》2009,23(13):1865-1873

Chloride is a major anion in soil water and its concentration rises essentially as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for isolated trees, shelterbelts or hedgerows. This article deals with the influence of a tree hedge on the soil and groundwater Cl^? concentrations and the possibility of using Cl^? as an indicator of transpiration and water movements near the tree rows. Cl^? concentrations were measured over 1 year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge. We observed a strong spatial heterogeneity of Cl^? concentrations, with very high values up to 2 g l^?1 in the unsaturated zone and 1·2 g l^?1 in the upper part of the groundwater. This contrasts with the low and homogeneous concentrations (60–70 mg l^?1) in the deeper part of the groundwater. Cl^? accumulation in the unsaturated zone at the end of the vegetation season allows us to identify the active root zone extension of trees. In winter, upslope of the tree row, downwards leaching partly renews the soil solution in the root zone, while the slow water movement under the trees or farther downslope results in Cl^? accumulation and leads to a salinization of the soil and groundwater. This salinization is of the same order as experimental conditions produce negative effects on oak seedlings. The measurement of Cl^? concentrations in the unsaturated zone under tree rows at the end of the vegetation season would indicate whether certain topographic, pedological or climatic conditions are likely to favour a strong salinization of the soil, as observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献