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621.
Quality Mapping of Surface Water and Assessment of Treated and Untreated Waste-water Inputs into the Rhine and Main River Based on Microbial Enzyme Activities Microbial enzyme activities are used for an extension of the traditional quality mapping of surface water. In the following study, the enzymatic parameters were proved and validated on samples from various creeks and rivers in Baden-Württemberg and on samples gathered from the Rhine and Main Rivers (Germany). The test parameters should also be used for the control and the preservation of the capacity of the biological self-purification, which is the only natural and essential process in drinking-water conditioning of surface water. Main subject of the surveys was the development of criteria for an assessment of the measured enzymatical inhibition effects. Therefore, classes of inhibition and indices of inhibition are defined. 相似文献
622.
Radon-prone areas in Israel were mapped on the basis of direct measurements of radon (222Rn) in the soil/rock gas of all exposed geological units, supported by the accumulated knowledge of local stratigraphy and
sub-surface geology. Measurements were carried out by a modified alpha-track detection system, resulting in high radon levels
mainly in rocks of the Senonian-Paleocene-aged Mount Scopus Group, comprised of chert-bearing marly chalks, rich in phosphorite
which acts as the major uranium source. Issues of source depth, seasonal variations and comparison with indoor radon levels
are addressed as well. This approach could be applied to other similar terrains, especially the Mediterranean Phosphate Belt. 相似文献
623.
Holocene lateral expansion, peat growth and carbon accumulation on Haukkasuo, a raised bog in southeastern Finland 总被引:1,自引:0,他引:1
Paludification intensity and peat deposition on Haukkasuo bog in southeastern Finland were studied with peat stratigraphic investigations by taking 79 samples for 14 C carbon dating and 164 volumetric samples. Peat formation of Haukkasuo, a concentric raised bog, began about 10 400 cal. BP. Lateral expansion has been largely controlled by the flat clayey floor, which has favoured rapid growth of the bog. During the first 400 years of its existence the bog covered one-fifth, and in the following 2000 years one-half, of its present extent. The long-term carbon accumulation rate averages 22.3 g C/m2 /yr in the central part of Haukkasuo and 16.7 g C/m2 /yr in its margins. The highest rates of carbon accumulation over 500-year periods were recorded in the central part of the bog in 6500–5500, 3500–2500 and 1500–0 cal. BP. The rate of vertical peat increment was higher than average in these periods, and the peat was mainly slightly humified and, when close to the surface, un compacted. The rate of carbon accumulation was lowest in 5500–3500 and 2500–2000 cal. BP, when the rate of vertical growth was lower than average and the peat was more humified than average. The formation of peat, the rate of vertical peat increment and the succession of peat types in Haukkasuo have mainly been controlled by hydrological changes caused by local factors, although climatic factors might also be important. In particular, the formation of slightly humified peat in 3300–2700 cal. BP and during the last 1300 years can be related to humid climate. 相似文献
624.
U. RING 《Journal of Metamorphic Geology》1992,10(1):33-53
The eastern Central Alps consist of several Pennine nappes with different tectonometamorphic histories. The tectonically uppermost units (oceanic Avers Bündnerschiefer, continental Suretta and Tambo nappes, oceanic Vals Bündnerschiefer) show Cretaceous/early Tertiary W-directed thrusting with associated blueschist facies metamorphism related to subduction of the Pennine units beneath the Austroalpine continental crust. This event caused eclogite facies metamorphism in the underlying continental Adula nappe. The gross effect was crustal thickening. The tectonically lower, continental Simano nappe is devoid of any imprint from this event. In the course of continent-continent collision, high- T metamorphism and N-directed movements occurred. Both affected the whole nappe pile more or less continuously from amphibolite to greenschist facies conditions. Crustal thinning commenced during the regional temperature peak. A final phase is related to differential uplift under retrograde P–T conditions. Further thinning of the crust was accommodated by E- to NE-directed extensional deformation. 相似文献
625.
Tropical air-sea interaction in general circulation models 总被引:10,自引:0,他引:10
626.
627.
A ROBUST PLS PROCEDURE 总被引:1,自引:0,他引:1
A robust partial least squares(PLS)regression algorithm is developed.This is achieved by substitutionof the univariate regression steps in the iterative PLS2 algorithm by a robust alternative.The anglebetween loading vectors from both perturbed and unperturbed solutions is used as a measure ofrobustness.By means of a perturbation study on a structure-activity data set,it is demonstrated thatthe stability of the robust method is superior to standard PLS. 相似文献
628.
Zooplankton in saline lakes of the Southern Interior Plateau of British Columbia were collected on three occasions: mid-May
and early August, 1990, and in late July, 1991. Salinities ranged from 2.6 to 45.8 g L−1. Of the 17 lakes examined, 13 were hyposaline (∼-20g L−1), four, mesosaline (20–50 g L−1) and none, hypersaline (>50 g L−1). pH ranged from 8.7 (Three Mile) to 10.7 (Goodenough), with values <9.6 in 10, and <9.0 in only three lakes. Lakes with
high pHs had high bicarbonate-carbonate alkalinities.
Thirty one species of zooplankton occurred: Protista (1), Rotifera (13), Anostraca (2), Cladocera (7), Ostracoda (1) and Copepoda
(7). Sixteen species were restricted to hyposaline waters, with seven found only in salinities of ≤5 gL−1. Two species (Diaptomus connexus, Artemia franciscana) were restricted to mesosaline waters of salinity >35 g L−1. Eurysaline species includedBrachionus plicatilis, Hexarthra fennica, Limnocythere staplini, Artemia franciscana andDiaptomus connexus. Most species were abundant in 1+ lakes, but six species always had low populations.B. plicatilis, Hexarthra polyodonta, A. franciscana, Limnocythere staplini, Daphnia similis andD. connexus had densest populations in one or more of the three most saline lakes, viz. Long, Goodenough and Three Mile. Cladocerans
other thanD. similis (Alona sp., Ceriodaphnia quadrangula, Daphnia pulex) were usually abundant in lakes of low salinity (<5 g L−1).Diatomus sicilis, present in all except the three most saline lakes, also occurred in abundance in ten of these lakes.Moina hutchinsoni andH. polyodonta were present in both hyposaline and mesosaline lakes, but, more importantly, tended to occur only at higher pH values (>pH
9.4) but not in all such lakes. These can be regarded as alkaline-saline species.
Sorensen’s Coefficient of Community Similarity was used to compare communities in Alberta-Saskatchewan and British Columbia.
It was low (0.37). A comparison restricted to just Cladocera gave a slightly higher value, 0.44, but a comparison of Copepoda
gave a value of 71 per cent similarity between the regions. Multiple regression analyses using pH, TDS and K regressed on
species richness for all samples accounted for only 41 per cent of the variance. However, when the analysis was seasonally
restricted (May), and thus to a limited chemical range, 47 to 77.5 per cent of the variance was accounted for by these three
variables. 相似文献
629.
630.
Isotope dilution mass spectrometry with negative thermal ions was applied to determine Cl, Br and I in rocks which, in part,
contained less than 100 ppb of Br and I. Two sets of samples have been investigated: a) a series of Al-rich metapelites of
increasing metamorphic grade from the Damara Orogen, Namibia and b) fresh and hydrothermally altered greywackes from the Pb−Zn
deposit Bad Grund in Germany. It was found that regional metamorphism of Al-rich metapelites causes no strong fractionation
of the halides. The Br/Cl ratios in the metapelites are similar to those of sea water. The I/Cl and I/Br ratios, however,
are 500 times higher. The I depleted in the ocean most probably is associated with organic matter stored in sediments. The
unaltered greywackes from near the Pb−Zn vein have about the same concentrations of halides as the metamorphic Al-rich pelites.
By contrast, the hydrothemally altered greywackes contain about twice as much Cl and I, and about 2–5 times as much Br as
the unaltered samples. The element ratios, however, are similar for all three categories of rocks, thereby indicating that
sea water played no role in the hydrothermal system. 相似文献