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Kimmo Smolander Risto J?rnstr?m Annika Sajalinna 《Fresenius' Journal of Analytical Chemistry》1989,335(4):392-394
Summary The matric effect of boric acid was investigated in the determination of iron in the primary circuit coolant water of nuclear power plants by furnace atomic absorption spectrometry. The effect of boric acid was of particular interest. The method was applied during refuelling and maintenance periods and the results were used to interpret the chemical changes in the water.
Einfluß von Borsäure auf die Bestimmung von Eisen in Reaktorkühlwasser durch GF-AAS相似文献
6.
Studies of extractions of yttrium from aqueous solution into chloroform, benzene, methyl isobutyl ketone, and mixtures of these solvents, containing thenoyltrifluoroacetone are described. The effects of reagent concentration, added n-butylamine, and added fluoride were investigated. Values of pH and Pe were determined, and identifications of the involved species are suggested. 相似文献
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The application of parallel processing techniques to molecular mechanics calculations is evaluated. Using the standard molecular mechanics package, MM2, four different parallel versions of the program are implemented in a four-processor computing environment. A set of 529 test structures is used to compare the efficiency of the parallel versions of MM2 to a standard serial version of the program. Statistics describing execution times and program execution cycles are gathered and analyzed. The effects of parallel processing overhead and computer system load are explored, and the practical utility of parallel processing in molecular mechanics is estimated. The results of these parallelization experiments indicate that for geometry optimizations requiring significant amounts of computing time an improvement in program execution speed approaching 50% is realizable. © 1993 John Wiley & Sons, Inc. 相似文献
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Mg2Ru5B4 and Mg5Ru13B11, Two Ternary Magnesium Ruthenium Borides with Channel Structures The ternary borides Mg2Ru5B4 and Mg5Ru13B11, crystallizing in the orthorhombic space group Pbam, were prepared by reaction of the elementary components in sealed tantalum ampoules. Mg2Ru5B4 (a = 1000.0(2) pm, b = 837,6(1) pm, c = 295.42(3) pm, Z = 2, RW = 0.027 for 563 reflections) is homeotypic with Sc2Ru5B4. The structure contains BRu6-trigonal prisms, connected by faces and edges to form pentagonal channels filled with chains of magnesium atoms. Mg5Ru13B11 (a = 2190.1(2) pm, b = 996.7(2) pm, c = 294.65(3) pm, Z = 2, RW = 0.031 for 959 reflections) has a similar but so far unknown structure in which parts of the magnesium and boron atoms are disordered. 相似文献
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Reversed-phase LC-MS/MS is used to determine major estrogenic alkylphenol ethoxylates (APEOs) and their biotransformation products. It allows the simultaneous analysis of eight APEOs, alkylphenoxy carboxylates (APECs) and alkylphenols (APs) in sewage treatment plant (STP) effluents in the same extract after solid-phase enrichment on polymeric Oasis HLB. As precursor ions, [APEO + NH4]+, [APEC - H]- and [AP - H]- were monitored. Instrumental limits of detection (LOD) were 2-600 pg, corresponding to sample concentrations of 0.04-12 ng l(-1), without correction for overall method recoveries. Matrix-induced signal suppression during electrospray ionisation (ESI) and extraction as well as overall method recoveries were assessed and the suitability of deuterated surrogates as internal standards was evaluated. 相似文献
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Extraction of radiolabeled cobalt(II) from aqueous solution into one or more solvents using 25 reagents was studied. Both reagent concentration and pH variation were investigated. The relevant association and partition constants for several of the better reagent-solvent systems were determined. These systems were hexanoic acid in I-hexanol, octanoic acid in I-octanol, and thenoyltrifluoroacetone in benzene. 相似文献