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251.
Rostislav Červenka Antonín Bednařík Josef Komárek Markéta Ondračková Pavel Jurajda Tomáš Vítek Petr Spurný 《Central European Journal of Chemistry》2011,9(6):1109-1116
The determination of mercury in fish typically involves analysis of muscles. For predicting the concentration of mercury in
fish muscle on the basis of the analysis of fish scales or fins, the relationship between total mercury concentrations in
fish muscles and in fish scales and fins was studied. Mercury content in fish muscles, scales and fins was determined by atomic
absorption spectrometry with thermal decomposition of the sample in a flow of oxygen. A number of scale treatments were applied
in order to remove impurities and to enhance the prediction quality. For scale treatment, 40 min of washing with DI water
in an ultrasonic bath is recommended. A coefficient of determination r2= 0.93 for the relationship between Hg concentrations in muscles and scales was achieved for 40 fish among the different fish
species tested (European bream, perch, roach) from the Hamry Reservoir, Czech Republic. With respect to fin sampling, the
coefficient of determination r2 for these fish was 0.86. The analysis of fish scales and caudal fins is a useful screening tool for assessing the relative
mercury contamination of monitored fish. The method of sampling scales is not suitable for fish species with small scales
such as brown trout.
相似文献
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Franz‐Josef K. Rehmann Laurence P. Cuffe Oscar Mendoza Dilip K. Rai Nigel Sweeney Katja Strohfeldt William M. Gallagher Matthias Tacke 《应用有机金属化学》2005,19(3):293-300
Starting from 2‐furylfulvene (1a) , 2‐thiophenylfulvene (1b) , and 1‐methyl‐2‐pyrrolylfulvene (1c), [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐furyl)ethanediyl] titanium dichloride (2a) , [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐thiophenyl)ethanediyl] titanium dichloride (2b) , and [1,2‐di(cyclopentadienyl)‐1,2‐bis‐(1‐methyl‐2‐pyrrolyl)ethanediyl] titanium dichloride (2c) were synthesized. When titanocenes (2a–c) were tested against pig kidney carcinoma cells (LLC‐PK), inhibitory concentrations (50%) of 4.5 × 10?4 M , 2.9 × 10?4 M and 2.0 × 10?4 M respectively were observed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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The dyadic diaphony, introduced by Hellekalek and Leeb, is a quantitative measure for the irregularity of distribution of point sets in the unit-cube. In this paper we study the dyadic diaphony of digital nets over ℤ2. We prove an upper bound for the dyadic diaphony of nets and show that the convergence order is best possible. This follows from a relation between the dyadic diaphony and the
L2{\cal L}_2
discrepancy. In order to investigate the case where the number of points is small compared to the dimension we introduce the limiting dyadic diaphony, which is defined as the limiting case where the dimension tends to infinity. We obtain a tight upper and lower bound and we compare this result with the limiting dyadic diaphony of a random sample. 相似文献
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Abstract— Corrected emission spectra and fluorescence lifetimes of polycytidylic acid in ethylene glycol: water glass at low temperatures are reported. Luminescence properties observed exhibit a strong dependence on pH and temperature. At neutral pH a vibronic structure of a blue part of the fluorescence spectrum is revealed when temperature is changed from 77 to 10 K, confirming that a monomer component of fluorescence is present. There is also a strong difference in decay of a red-shifted excimer fluorescence at 10 K at pH 7 and pH 3.9, reflecting a different protonation of cytosine residues and different conformations of polynucleotides in such conditions. 相似文献
260.
Josef Schelble 《Journal of magnetism and magnetic materials》1993,120(1-3):122-124
Oleic acid is an excellent lubricant in professional audio tapes. The oxidation sensitivity and the stabilization of oleic acid in studio tapes has been tested. Radical scavenging antioxidants which are unvolatile, compatible with the coating, and toxicologically safe turned out to be the most suitable stabilizers. 相似文献