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11.
Poecilia reticulata PETERS (guppy) and the green alga Monoraphidium griffithii were used for testing of different fluorotensides. After the representation of the methods of investigation and the definition of criteria of toxicity the obtained results of investigation are discussed. In general, the toxicity of the four investigated fluorotensides to algae was lower than to fish. The anionic fluorotenside CF3—(CF2)n—CFH—COONa was an exception. In tables and diagrams the results are summarized. Finally, for the condition of the receiving-water biocenosis class “2” the respective still permissible matter concentrations are proposed. They vary between 0.05 and 0.2 mg/1. 相似文献
12.
Four fluorotensides which are used mainly industrially are investigated with respect to their removability from waters. Since, in general, fluorotensides are difficult to remove or not at all removable biochemically, the effects of chemical or physicochemical treatment processes are tested. As the results represented in pictures and tables show, different modes of behaviour can be recognized with respect to the respective purification effect for the investigated fluorotensides, partly among them. Flocculation with Al- and Fe-salts as well as chlorination and ozonization show only partial effects. But all the investigated fluorotensides can be adsorptively eliminated by means of powder or granular active charcoal and adsorbent resin Wofatit EA60. 相似文献
13.
Salmo gairdneri, Cyprinus carpio, Poecilia reticulata, Leuciscus idus melanotus, Asellus aquaticus, Ankistrodesmus falcatus and Monoraphidium griffithii were exposed to four growth regulating herbicides, four photosynthesis toxicants, lindane, an anionactive tenside, KCN and Na3[Cu(CN)4] in standardized toxicity tests. The biochemical degradability of the substances was tested with activated sludge. In order to test the possible effects in waters there should be used Salmo for the oligosaprobic zone. Poecilia as well as Ankistrodesmus and Monoraphidium provide reliable estimations for β-mesosaprobic waters. With respect to the longer-term permission of plant protection products, besides Salmo there can be recommended also Leuciscus. 相似文献
14.
M. Tscheu-Schlüter 《洁净——土壤、空气、水》1983,11(2):169-179
The toxic effects of alkali cyanide, complex cyanide-containing heavy metal salts—as of iron, cadmium, copper, nickel and mercury—were investigated according to standard methods with the aid of the test organisms Poecilia reticulata (guppy) as well as the green alga Ankistrodesmus falcatus (β- bis α-mesosaprobic). Since various complex compounds can be photolytically decomposed, also discontinuous light-dark phases were used. As discussed equilibrium calculations have shown, inter alia also the pH-value is important in the fish organisms used with different reactions to ions and molecularly dissolved compounds. The results are summarized in tables and graphic representations, the substances investigated being classified into groups with “strong” and “high” toxic actions. 相似文献
15.
Recently obtained palaeomagnetic data have given a fairly detailed apparent polar wander (A.P.W.) curve for the Mesozoic of the Transdanubian Central Mountains which has been compared with other A.P.W. curves from the Mediterranean area. The similarity of the A.P.W. curves enabled a unified A.P.W. curve to be constructed for the Central Mediterranean region. It has been shown that the new Mediterranean A.P.W. curve is in full agreement, even in details, with the updated A.P.W. curve for Africa.This confirms the existence during the entire Mesozoic of a single Central Mediterranean megatectonic unit rigidly attached to Africa. Its positions with respect to the pole can now be traced back in more detail than before. 相似文献
16.
17.
Two colour laser ranging to artificial satellites is an attractivetechnique, which is capable to provide refraction corrected ranges without the need of an atmospheric model by measuring the dispersive delay of laser pulses of different wavelength. Although the required accuracy of the detection scheme is stringent, the technique has matured so far, that routine two colour observationsbecame feasible.The present paper describes a normal point procedure reducing two colour laser range observations with respect to the dispersive delay,exploiting the knowledge of satellite response signatures in conjunction with detector characteristics and the appropriate center of mass correction models.Moreover the dispersion model of the atmosphere is briefly reviewed, paying attention to the wavelength domains provided by modern twocolour ranging lasers, e.g., the Ti:SAP laser.Preliminary data is presented and compared to both, normal point data reduced with a standard procedure and zenith path equivalent meteorological parameters. 相似文献
18.
Tobelite (NH4) Al2 [AlSi3O10] (OH)2, the ammonium analogue of muscovite, and its deuterated form ND4-tobelite (ND4) Al2 [AlSi3O10] (OD)2 have been synthesised at 600?°C and 200 and 500 Mpa using a well homogenised, stoichiometric SiO2-Al2O3 oxide mix with Al2O3 in excess of 5 mol% and a 25% NH3 solution whose relative abundance was such that the amount of NH4 + stoichiometrically available was in excess of 50%. Characterisation of both tobelite and ND4-tobelite using IR-spectroscopy, Rietveld refinement of X-ray powder diffraction data, and electron microprobe analysis indicate that, similar to K+ in muscovite, the NH4 + or ND4 + molecule occupies the interlayer site. IR absorption bands caused by NH4 + and ND4 + can be explained, to a very good approximation, on the basis of Td symmetry. Nevertheless, substantial line broadening and the occurrence of shoulders indicate a deviation from ideal Td symmetry. However, even at 77?K, no discrete splitting of the degenerate states could be confirmed. The OH stretching frequencies observed for synthetic tobelite are quite similar to those for muscovite, indicating that the replacement of K+ by NH4 + has no effect. The low FWHH of the OH bands indicate that the hydroxyl groups are well ordered within the structure. Rietveld refinement of tobelite and ND4-tobelite indicates that all samples synthesised consist of the 3 different mica polytypes which are typical of muscovite – namely 1M (C2/m), 2M 1 (C2/c) and 2M 2 (C2/c). Tobelite and ND4-tobelite synthesised at 500 Mpa principally contain the 1M polytype, whereas the principle polytype for ND4-tobelite synthesised at 200 Mpa, is 2M 2. Rietveld refinement of X-ray diffraction spectra for tobelite synthesised at 200 Mpa was problematic due to the very broad FWHH of the X-ray peaks indicating poor crystallinity. In comparision to synthetic muscovite, the cell dimensions observed for tobelite and its deuterated analogue are quite similar except for the lattice constant c. Due to the larger radius of NH4 + or ND4 + compared to K+ cation, the c-direction is expanded form 10.275 Å in muscovite to approximately 10.540 Å in tobelite and ND4-tobelite. 相似文献
19.
J. Schlüter L. Schultz F. Thiedig B. O. Al‐Mahdi A. E. Abu Aghreb 《Meteoritics & planetary science》2002,37(8):1079-1093
Abstract— As of July 2001, 1238 Libyan meteorites have been reported. Most were found in two areas called Dar al Gani and Hamadah al Hamra. Dar al Gani is located on a plateau of marine carbonate rocks with marly components. Eight‐hundred and sixty‐nine meteorites between 6 g and 95 kg totalling 687 kg have been found here but the calculated mean recovery density is comparatively low with one meteorite on 6.5 km2. Dar al Gani is a perfect site for the recognition and preservation of meteorites. The existence of meteorites is the result of a combination of specific geological and geomorphological conditions: there is a bright‐colored, old limestone plateau (<2 Ma), under arid weather conditions over long periods of time, with rapid elimination of surface water if present and low erosion rates. The preservation of meteorites is guaranteed through the absence of quartz sand on the plateau, strongly reducing wind erosion and a basic environment emerging from the carbonate ground retards rusting of metallic meteorite components. A supposed soil cover during pluvial times has probably protected older meteorites and led to a concentration of meteorites of different periods. An evaluation of Dar al Gani meteorites suggests the existence of at least 26 strewnfields and 26 meteorite pairs reducing the number of falls to, at most, 534. Shock and weathering grades as a tool for the recognition of pairings turned out to be problematic, as several strewnfields showed paired meteorites which had been classified to different shock and weathering grades. 相似文献
20.