On the Elimination of Organic Microcontaminants by Flocculation with Lime Hydrate     

H.-J. Walther 《洁净——土壤、空气、水》1985,13(2):223-228

For the purpose of utilizing domestic flocculants for the treatment of water and of reducing by this the equivalent imports of metal salts, in this paper the result of investigations made on model waters and on a river water sample is described. The model waters contained the pesticides Atrazin, Diuron and 2,4-D, which partly were polluted in addition with different quantities of fulvic and humic acids as well as with colloidal substances causing turbidity (Friedland clay and finely dispersed cellulose). The investigations were supplemented by testing several adsorption media as γ-aluminium oxide, active carbon and diatom earth. In the presence of fulvic and humic substances one does not succeed in eliminating the investigated herbicides by flocculation with lime hydrate. Only after chemical side reactions between these contained substances the adsorbability is clearly influenced. The different elimination efficiencies at different reaction conditions are explained in detail.  相似文献   

Zur Elimination organischer Verbindungen durch Adsorberpolymere     

H. J. Walther  R. Kümmel  E. Worch  E. Tsaussides  R. Hellmig 《洁净——土壤、空气、水》1985,13(5):567-581

An investigation is made into the performance of a commercial product (Wofatit EP 61) and of newly-developed experimental samples of macroporous adsorption polymers (copolymers of styrene and divinyl benzene) with a much larger specific surface in batch and filter experiments. Against organic adsorptives having the character of weak electrolytes, adsorption polymers show a significantly pH-dependent elimination capacity. Non-ionic or only weakly dissociated anionic adsorptives are removed by the experimental samples to a much higher degree than by the commercial adsorption polymer. Highly dissociated anionic compounds can be removed by activated carbon better than by macroporous adsorption polymers.  相似文献   

Tidal correction of hydrographic measurements     

Carsten W. Brockmann  Dr. Joachim W. Dippner 《Ocean Dynamics》1987,40(6):241-260

Summary A simple procedure is presented to eliminate the influence of tidal oscillation from hydrographic measurements. This is done with a transformation from a co-ordinate system fixed in space to a co-ordinate system fixed in time using results of a numerical tidal model. The procedure is applied to a hydrographic survey in the German Bight. The hydrographic structure transformed onto a co-ordinate system fixed in time is much more similar to the structure obtained by satellite pictures and shows dynamical processes much clearer than in a co-ordinate system fixed in space.

---

Gezeitenkorrektur von hydrographischen Messungen

Zusammenfassung In dieser Arbeit wird ein Verfahren vorgestellt, das hydrographische Messungen vom Einfluß periodischer Variationen durch die Gezeiten bereinigt. Dies geschieht unter Benutzung von Ergebnissen eines numerischen Modells durch eine Transformation einer gemessenen hydrographischen Struktur von einem ortsfesten in ein zeitfestes System. Dieses Verfahren wird auf eine hydrographische Aufnahme der Deutschen Bucht angewandt. Die auf ein zeitfestes Koordinatensystem transformierte hydrographische Messung zeigt sehr viel Ähnlichkeit mit einer synoptischen Messung, die bei einem Satellitenüberflug gewonnen wurde. Bestimmte dynamische Prozesse in der Deutschen Bucht lassen sich zudem im zeitfesten Koordinatensystem besser erkennen als im ortsfesten Koordinatensystem.

---

Correction de l'influence de la marée sur les mesures hydrologiques

Résumé L'article présente une méthode simple pour éliminer l'influence de la marée sur les mesures hydrologiques. Cela est obtenu par le passage d'un système de coordonnées fixe dans l'espace à un système de coordonnées fixe dans le temps utilisant les résultats d'un modèle numérique de marée. La méthode est appliquée à un levé hydrologique dans la Baie Allemande. La structure hydrologique obtenue dans un système de coordonnées fixe dans le temps est beaucoup plus proche de celle qui est obtenue par les images satellites et décrit le processus dynamique beaucoup plus clairement que dans un système de coordonnées fixe dans l'espace.

  相似文献   

Identification of a collapsing protostar     

Neal J. Evans II  Shudong Zhou  Carsten Kömpe  C. M. Walmsley 《Astrophysics and Space Science》1994,212(1-2):139-145

The globular molecular cloud B335 contains a single, deeply embedded, far-infrared source. Our recent observations of H₂CO and CS lines toward this source provide direct kinematic evidence for collapse. Both the intensity and detailed shape of the line profiles match those expected from inside-out collapse inside a radius of 0.036 pc. The collapse began about 1.5 × 10⁵ years ago, similar to the onset of the outflow. The mass accretion rate is about 10 times the outflow rate, and about 0.4M should have now accumulated in the star and disk. Because B335 rotates only very slowly, any disk would still be very small (about 3 AU). The accretion luminosity should be adequate to power the observed luminosity. Consequently, we believe that B335 is indeed a collapsing protostar.Paper presented at the Conference onPlanetary Systems: Formation, Evolution, and Detection held 7–10 December, 1992 at CalTech, Pasadena, California, U.S.A.  相似文献   

A Global Dynamic Model for the Neolithic Transition     

Kai W. Wirtz  Carsten Lemmen 《Climatic change》2003,59(3):333-367

During the Holocene strong gradients in the distribution of technologyincluding subsistence ways emerged on a global scale.These patterns were further amplified in historic times and are stillvisible through worldwide differences in national wealth.In order to evaluate major factors responsible for the shift fromforaging to food production we here employ quantitative methods bydeveloping a deterministic but simple model. After compiling existing maps of potential vegetation at 5000 BP theinhabited world is split into 197 regions with homogeneous environmentalconditions. Suitable variables for the macro-economic and culturaldevelopment in the Neolithic period are found to be farming to hunting-gatheringratio, number of agricultural economies and a technological development index.The model explicitly describes economic adaptation, growth and migrationof human populations together with the spread of their cultural characteristics; it accounts for over-exploitation of natural resources, crowdingmortality and the climate variability on a millennium scale.In a thorough model validation region specific trajectories are compared toarchaeological evidence revealing a high correspondence. Major parts of the knownsequence of Neolithic centers including the timing differences are robustlyreproduced. A series of known problems in prehistory is discussedcomprising the lag between domestication and full scale farming, the off-levelingof the technological boost following the transition, the emergence ofdistinct migration waves and sensitivity to climate fluctuations.Not mere population pressure but continuous innovation and competition betweensubsistence strategies is identified as a prime mover of agricultural development.The results suggest that few aspects of biogeography may have determined theobserved continental gradients in the number of domesticable species ultimatelyleading to an increasing differentiation in technology and demography.  相似文献   

A wind-driven model of the ocean surface layer with wave radiation physics     

Olbers  Dirk  Jurgenowski  Philipp  Eden  Carsten 《Ocean Dynamics》2020,70(8):1067-1088

Ocean Dynamics - Surface windstress transfers energy to the surface mixed layer of the ocean, and this energy partly radiates as internal gravity waves with near-inertial frequencies into the...  相似文献   

The energetics of internal tides at the Luzon Ridge     

Han  Bing  Eden  Carsten 《Ocean Dynamics》2019,69(9):1009-1022

Ocean Dynamics - Three-dimensional simulations of the M2 and K1 internal tides using the MIT General Circulation Model (MITgcm) configured for the Luzon Ridge are presented. The energetics of M2...  相似文献   

Automated placement of supplementary contour lines     

Timofey Samsonov  Sergey Koshel  Dmitry Walther  Bernhard Jenny 《International journal of geographical information science》2019,33(10):2072-2093

Supplementary contour lines are placed between regular contour lines to visualize small but important forms that regular contour lines are unable to show. On topographic maps, typical forms are hillcrests, depressions, saddles, terraces, banks, and levees. No automated method for the selection of supplementary contour lines has been described so far. We document cartographic design principles for the selection of supplementary contour lines for topographic maps, and present an automated method for their placement. Results of the automated method are similar to manually placed supplementary contour lines. Our method helps map authors to create contour line maps that more effectively illustrate relevant small details in maps showing terrain elevation or other scalar fields.  相似文献   

New insights into Southern Caucasian glacial–interglacial climate conditions inferred from Quaternary gastropod fauna     

Christiane Richter  Daniel Wolf  Frank Walther  Stefan Meng  Lilit Sahakyan  Hayk Hovakimyan  Tilmann Wolpert  Markus Fuchs  Dominik Faust 《第四纪科学杂志》2020,35(5):634-649

In the present study, we performed gastropod analyses on loess–palaeosol sequences from northeast Armenia (Southern Caucasia) covering at least three glacial–interglacial cycles. The elaborated ecostratigraphy shows significant patterns of species composition related to the succession of pedocomplexes and loess, respectively. Pedocomplexes included species that can be associated with high-grass to forest-steppe biomes, indicating increased humidity for these sections compared to the loess layers. In contrast, loess layers that relate to glacial periods are associated with gastropod species of semidesert environments with shrub- and shortgrass-steppes, indicating semiarid to arid conditions. Furthermore, the loess deposits do not show any evidence for cold-adapted gastropod species. Therefore, we suggest that average July temperatures in the study area were above 10 °C, even during periods of loess deposition. Consequently, we propose that the limiting factor for tree growth during glacial periods was aridity, rather than temperature. In addition, we observe environmental differences between the various glacial times, with our results indicating a trend towards steadily increasing aridity in Southern Caucasia across the Middle to Late Pleistocene.  相似文献   

Prediction of Blast-Induced Ground Vibration in an Open-Pit Mine by a Novel Hybrid Model Based on Clustering and Artificial Neural Network     

Nguyen  Hoang  Drebenstedt  Carsten  Bui  Xuan-Nam  Bui  Dieu Tien 《Natural Resources Research》2020,29(2):691-709

Natural Resources Research - Ground vibration (PPV) is one of the hazard effects induced by blasting operations in open-pit mines, which can affect the surrounding structures, particularly the...  相似文献