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141.
Occurrence of Industrial Chemicals (HPS, BPS, and SPS) in Surface Water The paper gives the results of water examinations for different phenylsulfonamides. Random samples taken every month between May 1999 and August 2000 from surface water out of the river Rhine (kilometer 838), the river Ruhr (Mülheim Styrum) and the river Emscher (Oberhausen center) were tested for the corrosion inhibiting agent 6‐[methyl(phenylsulfonyl)amino]‐hexanoic acid (HPS) as well as its metabolites 4‐[methyl‐(phenylsulfonyl)amino]‐butanoic acid (BPS) and sarkosin‐N‐(phenylsulfonyl) (SPS). Furthermore, the sewage plant effluents of two municipal wastewater treatment plants from the rural area were also included in the monitoring program. The analytical method includes solid‐phase extraction (SPE), a derivatization step as well as gas chromatography mass spectrometry (GC‐MS). SPS is regularly found in all investigated surface waters, but only occasionally in the effluents of the two rural sewage plants. The median values for SPS amount to 0.09 μg/L in the river Rhine, 0.60 μg/L in the river Ruhr, and 0.70 μg/L in the river Emscher. BPS can only be found in the river Ruhr (median value: 0.08 μg/L) and in the river Emscher (median value: 0.41 μg/L). HPS was regularly found in a surface water for the first time. This substance can be detected in the Emscher through the whole measurement period. The median value for HPS amounts to 1.78 μg/L. Aditionally, the validation characteristics of an alternative analytical method including solid‐phase microextraction (SPME) is worked out. The fully automated process includes an on‐fiber methylation step and the GC‐MS. The repeatability standard deviation of the process amounts to RSD < 12%. Detection limits between 0.07 and 0.70 μg/L are achieved. 相似文献
142.
Friedrich Werner 《Marine Geology》1973,15(5):59-65
The optimum efficiency of the Kiel box corer (“Kastenlot”) is dependent upon certain mechanical properties of the sediments. To avoid this limitation, a new core catcher was constructed and has been tested for several years in both shallow and deep-water sediments. The essential part of this catcher is a reinforced canvas curtain which is pulled slantwise through the core before the corer is pulled out of the sediment. 相似文献
143.
144.
David W. Mittlefehldt Thomas H. See Friedrich Hrz 《Meteoritics & planetary science》1992,27(4):361-370
Abstract— We have analyzed small, ballistically dispersed melt samples in the form of aerodynamically shaped spheres, dumbbells, teardrops, etc., from Wabar Crater, Saudi Arabia, and have compared these to our previous study of the more massive, black and white melt specimens. The smaller melt samples differ from the more massive melts in that they are petrographically and chemically more homogeneous, possess fewer, more diffuse schlieren and contain much less clastic detritus. These observations suggest higher peak temperatures for the smaller melt samples than for the massive black and white melts which represent Wabar's major melt-zone. Analyses of the Wabar and Nejed (paired with Wabar) meteorites permit detailed comparison of the unaltered projectile with impactor residues in the melts. Siderophile element concentrations indicate that the small glass beads commonly contain > 10% meteoritic component, compared to < 5% for the massive black and white melts. One glass bead was found to contain ~ 17% meteoritic component. Based on models for melt production during cratering, we deduce that more meteoritic material was mixed with the upper stratigraphic horizons of Wabar's melt zone than with the lower parts. Siderophile elements in all Wabar melt specimens are fractionated relative to the Wabar-Nejed meteorite and have Fe/Ni ratios up to ~ 1.8 times that of Wabar-Nejed for the most siderophile element-rich glasses. The abundance sequence of siderophiles in the melts relative to the projectile is Fe ? Co > Ni ? Ir ? As » Au. Although this sequence seems incompatible with simple vapor fractionation of either elements or oxides, we believe that a complex vapor fractionation process most likely produced the observed siderophile element abundances. Our sample suite should be representative of all materials found in and around the Wabar structure, and we conclude that substantial quantities of the projectile were lost to the atmosphere, most likely as vapor. No fractionation of lithophile elements is observed in the glasses relative to the target rocks. Although fractionation of the impactor must have occurred prior to intimate mixing of projectile and target, details of the actual fractionation mechanism(s) remain poorly understood. The results of this study indicate that caution is necessary when attempting to define impactor types and masses from compositional data for impact melts from other craters. 相似文献
145.
The main cause for mid-period seismic ground distortions are ocean waves generated by atmospheric disturbances. These act upon the earth through different mechanisms. The microseismic wavefield can be divided into primary (T =12–18 s) and secondary (T = 6–9 s) noise. Classical theory tells that the origin of these induced ground distortions depends on the location and the intensity of the low pressure region. A considerable part of the microseismic wave field reaches the GRF-array in southern Germany with high coherency and almost constant amplitudes. Thus it is possible to locate the generating areas using frequency-wavenumber analysis. Five discrete generating areas for secondary microseisms and three generating areas for primary microseisms could be determined in the Atlantic Ocean, the Arctic Sea and the Mediterranean Sea by investigating broadband continuous recordings over four months in winter 1995/96. An essential result is the long-time constancy of the backazimuths of the coherent part of the microseismic wavefield with respect to the origin areas, independent of the location of the moving low pressure zone. Results from a triangulation using additionally broadband data from the NORSAR-array and an independent estimation of the distance of the source region with water wave dispersion data indicate an origin of the secondary microseismic wavefield near the north-Norwegian coast for the strongest source. The array analysis of a temporary network of ten three-component broadband stations in south-east Germany shows that the ratio of energy between coherent Love and Rayleigh waves is much higher for the primary than for the secondary microseismic noise wavefield. This indicates differences in the source mechanisms. 相似文献
146.
Friedrich Frhr. von Huene 《International Journal of Earth Sciences》1939,30(3):360-360
Ohne Zusammenfassung 相似文献
147.
Friedrich E. Zeuner 《International Journal of Earth Sciences》1938,29(6):514-517
Ohne Zusammenfassung 相似文献
148.
Friedrich Leyden 《International Journal of Earth Sciences》1924,15(3):193-215
Ohne Zusammenfassung 相似文献
149.
An attempt is made to outline a satisfactory general theory for the formation of Pacific deep-sea manganese nodules based
on a consideration of the time of initiation of formation of the nodules, a mechanism of maintenance of the nodules at the
sediment surface and the role of biological productivity of the surface waters in influencing nodule characteristics. Using
this model, the principal physical, chemical and distributional features of the nodules and reasons for their differences
on a regional scale in the Pacific can be interpreted. 相似文献
150.
Acquisition and Inversion of Dispersive Seismic Waves in Shallow Marine Environments 总被引:1,自引:0,他引:1
Gerald Klein Thomas Bohlen Friedrich Theilen Simone Kugler Thomas Forbriger 《Marine Geophysical Researches》2005,26(2-4):287-315
Two types of dispersive seismic waves have been acquired in different geological settings to investigate the potential to
reveal the elastic parameters of the shallow marine subsurface. Scholte waves as well as acoustic guided waves are excited
by a near-surface towed airgun, and recorded using two acquisition methods: (1) the towed-acquisition system using a hydrophone streamer towed close to the sea floor, and (2) the stationary-receiver method using Ocean-Bottom Seismometers and/or Hydrophones (OBS/OBH). Our diverse data sets reveal that the spatial sampling
of the wavefield required to avoid aliasing may vary significantly for different geological settings. Scholte waves are characterised
by a few distinct modes observed at low frequencies and low phase velocities. Their dispersion is mainly controlled by the
depth profile of the shear-wave velocity. Acoustic guided waves show profound amplitude variations of numerous higher modes
over a broad frequency range. These are sensitive to shear-wave velocity, but more sensitive to compressional-wave velocity
than Scholte waves are. To avoid the identification of distinct modes we infer 1-D models of elastic parameters of the subsurface
from the inversion of the full wavefield spectra of acoustic guided waves. In the Siberian Laptev Sea we infer the presence
of a soft sediment layer (8–10 m) with a well resolved strong S-velocity gradient (150–450 m/s). In the Baltic Sea a low P-velocity
layer with a strong vertical gradient (1250–1440 m/s) corresponding to a post-glacial gassy mud layer could be resolved, which
agrees well with the sediment stratigraphy derived from a gravity core. 相似文献