Modellierung und Simulation des Phytoplanktongehaltes in einem eutrophen Fließgewässer     

A. H. Gnauck  W. Winkler  K. Groth  F. Komoss  E. Six 《洁净——土壤、空气、水》1987,15(2):149-159

The model structure contains three compartments which are described by single models and are multiplicatively combined into an overall model of the net production of phytoplankton, the sedimentation of algae and the grazing by zooplankton being taken into account as loss quantities. The radiation and nutrients available (N, P, Si) are represented by Fourier models; the same holds for the water temperature. The light and temperature dependence of the growth rate are described by exponential equations, the nutrient dependence is described by the Monod statement. When the half-saturation constants and the sinking losses of the seasonally prevailing algae groups are taken into account, besides the total net production also the seasonal succession of the biomass of the different algae groups can be simulated realistically.  相似文献   

A 12,000-year history of vegetation and climate for Cape Cod,Massachusetts     

Marjorie Green Winkler 《Quaternary Research》1985,23(3):301-312

Pollen and charcoal analysis of radiocarbon-dated sediment cores from Duck Pond in the Cape Cod National Seashore provide a continuous 12,000-yr vegetation and climate history of outer Cape Cod. A Picea-Hudsonia parkland and then a Picea-Pinus banksiana-Alnus crispa boreal forest association grew near the site between 12,000 and 10,000 yr B.P. This vegetation was replaced by a northern conifer forest of Pinus strobus-P. banksiana, and, subsequently, by a more mesophytic forest (Pinus strobus, Tsuga, Quercus, Fagus, Acer, Ulmus, Fraxinus, Ostrya) as the climate became warmer and wetter by 9500 yr B.P. By 9000 yr B.P. a Pinus rigida-Quercus association dominated the landscape. High charcoal frequencies from this and subsequent levels suggest that the pine barrens association developed during a warmer and drier climate that lasted from 9000 to about 5000 yr B.P. Increased percentages of Pinus strobus pollen indicate a return to moister and cooler conditions by about 3500 yr B.P. A doubled sedimentation rate, increased charcoal, and increased herb pollen suggest land disturbance near the pond before European settlement. These results suggest a rapid warming in the northeast in the early Holocene and support a hypothesis of a rapid sea level rise at that time. Comparison of the pollen results from Duck Pond with those from Rogers Lake, Connecticut, illustrates the importance of edaphic factors in determining the disturbance frequency and vegetation history of an area.  相似文献   

Modellierung der Zwickauer Mulde –-Verhaltensmodelle     

H. Reissig  A. Gnauck  G. Grosse  W. Winkler  J. Beyer  P. Otto 《洁净——土壤、空气、水》1981,9(6):613-625

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Modellierung der Zwickauer Mulde - Beschreibungsmodelle     

A. Gnauck  H. Reissig  J. Wernstedt  W. Winkler  J. Beyer 《洁净——土壤、空气、水》1980,8(6):591-604

Für die Fließstrecke der Zwickauer Mulde zwischen den Pegeln Zwickau-Pölbitz und Göhren werden statische und dynamische Beschreibungsmodelle angegeben, die anhand kontinuierlich gewonnener Meßwerte von Einflußgrößen der Wasserbeschaffenheit mit einem Diskretisierungsabstand von Δt = 2 h gebildet wurden. Neben den statistischen Auswertungen werden rekursiv geschätzte Sauerstoffmodelle für den Pegel Göhren und für die gesamte Fließstrecke dargestellt.  相似文献   

Comptel analysis of GRB 940217     

C. Winkler  K. Bennett  L. O. Hanlon  K. S. O'Flaherty  O. R. Williams  R. M. Kippen  J. Ryan  W. Collmar  V. Schönfelder  H. Steinle  W. Hermsen 《Astrophysics and Space Science》1995,231(1-2):153-156

COMPTEL on board CGRO has observed a very strong (S[> 0.3 MeV] = 2.03 × 10^–4 erg cm^–2), complex, and long lasting (162 s) gamma-ray burst on February 17, 1994 (GRB 940217). Temporal fluctuations occur on timescales as short as 100 ms. Hard-to-soft spectral evolution has been observed during the burst emission and also within individual peaks. The photon spectra obtained within the 6 peaks can be modelled by single power law spectra and by broken power laws with break energies at around 1 MeV. The best-fit power law slopes vary between 1.1 and 3.5 throughout the event. The burst is located at [ ₂₀₀₀, ₂₀₀₀] = [29.5°, 3.8°] with a 3 error radius of 0.9°. COMPTEL does not detect any significant post-burst emission (as reported by EGRET) at low energies (< 30 MeV), and our upper limits are marginally consistent with the EGRET detections. Using high energy spectral and temporal information, distance limits to GRB 940217 have been derived.  相似文献   

Spectral characterisation of gamma-ray bursts with COMPTEL and BATSE     

L. O. Hanlon  K. Bennett  O. R. Williams  C. Winkler  R. D. Preece 《Astrophysics and Space Science》1995,231(1-2):157-160

Although the earliest observed gamma-ray burst spectra were well described by thermal bremsstrahlung models, subsequent observations above 1 MeV showed the existence of high energy power law tails in 60% of events. In order to accurately characterise burst spectra, both the low energy turnover and the high energy tail must be accounted for. We have addressed this issue by jointly deconvolving spectra obtained by BATSE and COMPTEL onboard theCompton Observatory. We present preliminary results obtained by application of this method to the gamma-ray burst of February 17, 1994.  相似文献   

Achieving development and mitigation objectives through a decarbonization development pathway in South Africa     

Katye E. Altieri  Hilton Trollip  Tara Caetano  Alison Hughes  Bruno Merven  Harald Winkler 《Climate Policy》2016,16(4):S78-S91

Achieving the international 2 °C limit climate policy requires stringent reductions in GHG emissions by mid-century, with some countries simultaneously facing development-related challenges. South Africa is a middle-income developing country with high rates of unemployment and high levels of poverty, as well as an emissions-intensive economy. South Africa takes into account an assessment of what a fair contribution to reducing global emissions might be, and is committed to a ‘peak, plateau and decline' emissions trajectory with absolute emissions specified for 2025 and 2030, while noting the need to address development imperatives. This work utilizes an economy-wide computable general equilibrium model (e-SAGE) linked to an energy-system optimization model (TIMES) to explore improving development metrics within a 14 GtCO₂e cumulative energy sector carbon constraint through to 2050 for South Africa. The electricity sector decarbonizes by retiring coal-fired power plants or replacing with concentrated solar power, solar photovoltaics and wind generation. Industry and tertiary-sector growth remains strong throughout the time period, with reduced energy intensity via fuel-switching and efficiency improvements. From 2010 to 2050, the model results in the unemployment rate decreasing from 25% to 12%, and the percentage of people living below the poverty line decreasing from 49% to 18%. Total energy GHG emissions were reduced by 39% and per capita emissions decreased by 62%.

Policy relevance

Lower poverty and inequality are goals that cannot be subordinated to lower GHG emissions. Policy documents in South Africa outline objectives such as reducing poverty and inequality with a key focus on education and employment. In its climate policy and Intended Nationally Determined Contribution (INDC), South Africa is committed to a peak, plateau and decline GHG emissions trajectory. As in many developing countries, these policy goals require major transformations in the energy system while simultaneously increasing affordable access to safe and convenient energy services for those living in energy poverty. The modelled scenario in this work focuses on employment and poverty reduction under a carbon constraint, a novel combination with results that can provide information for a holistic climate and development policy framework. This study has focused on the long term, which is important in generating clear policy signals for the necessary large-scale investments.  相似文献   

Wandel auf dem Gebiet der Gesteinsmetamorphose     

Prof. Dr. Helmut G. F. Winkler 《International Journal of Earth Sciences》1968,57(3):1002-1019

Zusammenfassung Der Konzeption der metamorphen Tiefenzonen vonBecke undGrubenmann wurde im Jahre 1915 die Konzeption der metamorphen Fazies vonEskola gegenübergestellt. Während die Fazieslehre neutral und hypothesenfrei ist, postuliert die Tiefenzonengliederung vonGrubenmann feste Korrelationen zwischen Temperatur, allseitigem Druck und Stress bei der Metamorphose. Es wird gezeigt, daß diese Abhängigkeit nicht besteht, daß die Intensität der Metamorphose nicht von der Tektonik abhängig ist, und daß es keine Stress- und Antistressminerale gibt.Ein überblick über den heutigen Stand der metamorphen Fazies wird gegeben, wobei insbesondere Angaben über die Temperaturgrenzen von Fazies aufgrund der neuesten Experimente gemacht werden. Es wird nachgewiesen, daß die maximalen Drucke sowohl bei niedrigtemperierter als auch bei hochtemperierter Metamorphose um 10 000 Atmosphären betragen haben. Regionale Metamorphosen können bei jeweils sehr verschiedenen Temperatur-Druckverteilungen erfolgt sein, wodurch verschiedene Typen, verschiedene metamorphe Faziesserien entstanden sind.

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The concept of depthzones byBecke andGrubenmann is contrasted withEskola's concept of metamorphic facies. While the concept of metamorphic facies is neutral and free from any hypotheses, the concept of depthzones postulates a firm correlation between temperature, pressure and directed pressure (stress) during metamorphism. It is shown that this correlation does not exist, that the grade of metamorphism is not dependent on tectonics, and that stress minerals and antistress minerals do not exist. A brief survey is given of the present state of metamorphic facies. Physical conditions, based on most recent experimental investigations, are stated and graphically represented in Fig. 3.The maximum pressures in metamorphism of crustal rocks have been about 10 000 atmospheres, both when very low temperatures and rather high temperatures were effective. Regional metamorphism has taken place under the condition of very different pressure-temperature relations (geothermal gradients) thus having produced different types of metamorphism, or different metamorphic facies series.--qr (Becke Grubenmann) (Eskola). . , , , - , , . .

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Résumé En 1915 la conception du faciès métamorphique d'Eskola fut opposée à celle des zones métamorphiques de profondeur deGrubenmann. Le système du faciès ne part pas de suppositions hypothétiques tandis que la division en zones de profondeur queGrubenmann établit postule pour le métamorphisme des correlations invariables entre température, pression isotrope et stress. On démontre qu'un tel rapport fixe n'existe pas, que l'intensité du métamorphisme ne dépend pas de la tectonique et que des minéraux de stress et d'antistress n'existent pas.Une vue d'ensemble sur la situation actuelle des recherches portant sur les faciès métamorphiques est présentée et par là des données sur les limites de température des faciès sur la base des expériences très récentes sont fournies. Il est démontré que les pressions maximales qui sont atteintes au cours du métamorphisme non seulement à basse température mais encore à haute température se montent à 10 000 atmosphères environ. La métamorphisme régional s'est produit sous des conditions très différentes de pression et de température. Ainsi naissent des types différents de faciès métamorphique.

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Plenarvortrag auf der Geowissenschaftlichen Tagung in Berlin am 8. Oktober 1967.  相似文献   

Die Struktur des K2MgF4     

Dr. Bruno Brehler  Dr. Helmut G. F. Winkler 《Contributions to Mineralogy and Petrology》1954,4(1-2):6-11

Zusammenfassung Die Struktur des K₂MgF₄ wurde untersucht. Es ergab sich: Raumgruppe I 4/m m m ₂,a ₀ = 3,977 Å,c ₀ = 13,16 Å, Inhalt der Elementarzelle zwei Formeleinheiten. Die Struktur besteht aus Schichten zweidimensional-unendlich miteinander verknüpfter MgF₆-Koordinationsoktaeder, was rich auch in der Art der Spaltbarkeit und Optik äußert.

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Herrn Professor Dr.Carl W. Correns zum 60. Geburtstag gewidmet.  相似文献   

Buchbesprechungen     

Woker  H. Hegi  R. Hantke  E. Winkler 《Aquatic Sciences - Research Across Boundaries》1963,25(1):152-155

Ohne Zusammenfassung  相似文献