Development of an improved empirical model for slant delays in the troposphere (GPT2w)   总被引：7，自引：0，他引：7  

Johannes Böhm  Gregor Möller  Michael Schindelegger  Gregory Pain  Robert Weber 《GPS Solutions》2015,19(3):433-441

  相似文献   

On the Multiplicity of the O-Star Cyg OB2 #8a and its Contribution to the γ-ray Source 3EG J2033+4118     

Michael De Becker  Gregor Rauw  Jean-Pierre Swings 《Astrophysics and Space Science》2005,297(1-4):291-298

We present the results of an intensive spectroscopic campaign in the optical waveband revealing that Cyg OB2 #8A is an O6+O5.5 binary system with a period of about 21.9 days. Cyg OB2 #8A is a bright X-ray source, as well as a non-thermal radio emitter. We discuss the binarity of this star in the framework of a campaign devoted to the study of non-thermal emitters, from the radio waveband to γ-rays. In this context, we attribute the non-thermal radio emission from this star to a population of relativistic electrons, accelerated by the shock of the wind-wind collision. These relativistic electrons could also be responsible for a putative γ-ray emission through inverse Compton scattering of photospheric UV photons, thus contributing to the yet unidentified EGRET source 3EG J2033+4118. Based partly on data Obtained at the Observatoire de Haute-Provence, France.  相似文献   

Factors that contributed to recent eutrophication of two Slovenian mountain lakes     

Gregor Muri  Branko Čermelj  Radojko Jaćimović  Tina Ravnikar  Andrej Šmuc  Janja Turšič  Polona Vreča 《Journal of Paleolimnology》2018,59(4):411-426

Increased eutrophication was recently observed in the 5th (5J) and 6th (6J) Triglav Lakes, two remote Slovenian mountain lakes. Sediment phosphorus (P) pools were analysed and potential external P sources affecting the lakes (atmospheric deposition, terrestrial export and nearby hut) evaluated, to assess the effects of internal and external changes on the lakes. A sequential extraction procedure was used to quantify five P fractions from the sediments: adsorbed (NH₄Cl–P), redox-sensitive (BD–P), aluminium- (NaOH–P) and calcium- (HCl–P) bound, and refractory organic (Res–P) P. Total phosphorus (TP) contents in surface sediment of 5J and 6J were 1430 and 641 µg P g^?1 dry weight sediment (dw), respectively. TP varied with depth in 5J sediments, but displayed no discernible pattern, whereas it decreased steadily downcore in 6J. Contents of all P forms were distinctly higher in 5J than 6J, but their rank order and relative abundances were similar in the two lakes. Res–P was the most abundant P fraction, followed by HCl–P. Together, the two P forms accounted for nearly 80 and 90% of TP in 5J and 6J sediments, respectively. BD–P and NaOH–P were less abundant, with each fraction accounting for 3 to 9% of TP, whereas NH₄Cl–P was least abundant. Atmospheric deposition and terrestrial export were substantial sources of P for the lakes. Delivery of the former was estimated to be at least 7.5 mg P m^?2 yr^?1 and the latter around 20 mg P m^?2 yr^?1. We concluded that P was not retained in the catchment effectively, likely because of only slightly acidic soil pH (5.9), relatively low aluminium content and high organic matter content (53%) in soils, resulting in higher vulnerability of the studied lakes to eutrophication. The mountain hut could also be a significant source of P for the lakes. Each year, it could potentially contribute ~12 kg of soluble P to the environment, but the true impact of the hut on lake trophic status remains unclear.  相似文献   

Complex zoning between super-calcic pigeonite and augite from the Graveyard Point sill, Oregon: a record of the interplay between bulk and interstitial liquid fractionation     

Gregor Markl  Craig White 《Contributions to Mineralogy and Petrology》1999,137(1-2):170-183

The 150 m thick late Miocene Graveyard Point sill (GPS) is situated at the Idaho-Oregon border near the southwestern edge of the western Snake River Plain. It records from bottom to top continuous fractional crystallization of a tholeiitic parent magma (lower chilled border, FeO/(FeO+MgO) = 0.59, Ni = 90 ppm) towards granophyres (late pods and dikes, FeO/(FeO+MgO) = 0.98, 78 wt% SiO₂ 3.5 wt% K₂O, <4 ppm Ni) showing a typical trend of Fe and P enrichment. Fractionating minerals are olivine (Fo₇₉-Fo₂), augite (X _Fe = 0.18−0.95), feldspars (An₈₀Or₁-An₁Or₆₂), Fe-Ti oxides (Ti-rich magnetite and ilmenite), apatite and in two samples super-calcic pigeonite (Wo_18–28 Fs_41–54). The granophyres may bear some quartz. Compositionally zoned minerals record a large interval of the fractionation process in every single sample, but this interval changes with stratigraphic height. In super-calcic pigeonite-bearing samples, olivine is scarce or lacking and because super-calcic pigeonite occurs as characteristic overgrowths on augite, its formation is interpreted to be related to the schematic reaction: augite + olivine (component in melt) + SiO₂ (in melt) = pigeonite, that defines the cotectic between augite and pigeonite in olivine-saturated basaltic systems. Line measurements with the electron microprobe reveal that the transition from augite to super-calcic pigeonite is continuous. However, some crystals show an abrupt “reversal” towards augite after super-calcic pigeonite growth. Two processes compete with each other in the GPS: fractional crystallization of the bulk liquid (the bulk melt separates from solids and interstitial liquids in the solidification front) and fractional crystallization of interstitial melt in the solidification front itself. Interplay between those two processes is proposed to account for the observed variations in mineral chemistry and mineral textures. Received: 25 November 1998 / Accepted: 14 June 1999  相似文献   

Historical impacts of mercury mining and stocking of non-native fish on ichthyofauna in the Idrijca River Basin,Slovenia     

Gregor Torkar  Žiga Zwitter 《Aquatic Sciences - Research Across Boundaries》2015,77(3):381-393

  相似文献   

High accuracy measurements of water storage change in Mining Lake 111, Germany     

Bertram Boehrer  Stephanie Kastner  Gregor Ollesch 《Limnologica》2010,40(2):156-160

Several pressure sensors were deployed in a small lake to determine its storage change. It could be shown that a deep enough deployment and an averaging over a time interval of 1 hour and 5 measuring points allowed for a measurement of 1 or 2 kg/m² (i.e. 2 mm of water column) of changes in the storage on the scale of the lake size. This accuracy for the lake storage could not be achieved by other methods, especially if conditions were difficult, e.g. snowfall, or in cases when precipitation was small. Finally, the pressure measurement - originally intended to roughly determine the water level - turned out to be a direct measurement of water mass in the lake, which was the proper magnitude for exchanges between atmosphere and lake. Hence the measurement of lake storage could become an interesting approach even for meteorological measurements, such as precipitation and evaporation on a water surface.  相似文献   

Meteorology and oceanography of the Atlantic sector of the Southern Ocean—a review of German achievements from the last decade     

Hartmut H. Hellmer  Monika Rhein  Günther Heinemann  Janna Abalichin  Wafa Abouchami  Oliver Baars  Ulrich Cubasch  Klaus Dethloff  Lars Ebner  Eberhard Fahrbach  Martin Frank  Gereon Gollan  Richard J. Greatbatch  Jens Grieger  Vladimir M. Gryanik  Micha Gryschka  Judith Hauck  Mario Hoppema  Oliver Huhn  Torsten Kanzow  Boris P. Koch  Gert König-Langlo  Ulrike Langematz  Gregor C. Leckebusch  Christof Lüpkes  Stephan Paul  Annette Rinke  Bjoern Rost  Michiel Rutgers van der Loeff  Michael Schröder  Gunther Seckmeyer  Torben Stichel  Volker Strass  Ralph Timmermann  Scarlett Trimborn  Uwe Ulbrich  Celia Venchiarutti  Ulrike Wacker  Sascha Willmes  Dieter Wolf-Gladrow 《Ocean Dynamics》2016,66(11):1379-1413

  相似文献   

The economics of leadership in climate change mitigation     

Gregor Schwerhoff 《Climate Policy》2016,16(2):196-214

Which kind of reaction can a nation or group of nations expect when leading by example in climate policy? This synthesis article describes possible positive reaction mechanisms from different fields of economics, some of which have scarcely been linked to climate economics previously. One effect may be behavioural, a reaction motivated by fairness, reciprocity, or norms. Second, other nations may interpret the leader's action as a signal on his preference or the value of the objective and adjust their own policy based on the new information. Third, the leader may provide a service to other nations, which decreases their costs and risks. The followers could benefit by learning successful policies, adopting technologies, and obtaining information on the cost of environmental policy. All of these mechanisms have in common that the leader sets an example with the intention of motivating others to contribute to the public good.

Policy relevance

A large body of both theoretical and empirical evidence shows that leading by example in climate change mitigation by a small group of nations has important potential for motivating other nations to follow. Modern economics has identified a range of mechanisms to explain why simple free-riding is unlikely to dominate the reaction to leadership. One such mechanism is described by behavioural economics. Humans often behave as conditional cooperators, meaning that they are willing to do their bit once a leader has done his. A second mechanism is the transmission of a credible signal that the leader considers climate change mitigation to be important. Finally, the leader gains knowledge, which spills over to other countries and thus moves their cost–benefit ratio in favour of mitigation. This evidence implies that leadership provides a promising alternative to stimulate the global cooperation that will eventually be needed to stabilize the climate.  相似文献   

Paleomagnetism and the alpine tectonics of Eurasia V: The paleomagnetism of some mesozoic and cenozoic volcanic rocks from the lebanon     

C.B Gregor  S Mertzman  A.E.M Nairn  J Negendank 《Tectonophysics》1974,21(4):375-395

A sampling of Mesozoic and Tertiary basalts in Lebanon yielded the following information: These results confirm and amplify earlier work by Van Dongen et al., and can be interpreted as indicating a net anticlockwise rotation of Lebanon relative to the African tectonic plate amounting to about 70° during the Late Jurassic-Pliocene interval. This could have resulted from differential movement between the African and European plates as they made way for the growing Atlantic Ocean.  相似文献   

Niederschlagsänderungen während eines Jahres in irhrer Beziehung zu den Frontalzonen     

A. Gregor  Z. Gregor 《Studia Geophysica et Geodaetica》1959,3(1):100-100

Sans résumé The online version of the original article can be found at  相似文献