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51.
52.
Mean bulk densities of various samples of dry atmospheric aerosol particles sampled at different sites and during different seasons and weather situations range between 1.8 and more than 3 gm cm3. 相似文献
53.
Volker Stähle 《Earth and Planetary Science Letters》1975,25(1):71-81
An extensive study of a big number of gneiss specimens with various shock features from the suevite allowed unravelling of the shock behavior of almandite garnets.Almandites in shocked metamorphic rocks show with increasing dynamic pressures strong irregular fracturing. differently oriented sets of planar fractures or elements, brown turbidity and nucleation of minute crystals of an unknown phase in solid garnets. At higher peak pressures garnet was found to break down to (1) orthopyroxene + spinel + glass, and to (2) spinel + glass due to fast shock-melting.Extensive quantitative electron microprobe studies of almandite garnets and their breakdown products were carried out. The breakdown products within the original grain boundaries of the garnets consist of an alumina-rich orthopyroxene (with up to 10 wt. % Al2O3), hercynite to pleonaste spinels and a silica and calcium-rich glass matrix. The chemical zonation of magnesium and manganese of the former garnets is inherited in the composition of the newly formed orthopyroxenes.Petrographic evidence and chemical composition suggest a fast breakdown of the almandite garnets after passing of shock waves at rapidly falling pressures and very high post-shock temperatures within the ejected gneissic rock material. 相似文献
54.
Dr. med G. Huber-Pestalozzi Hans Wolfgang Schäfer 《Aquatic Sciences - Research Across Boundaries》1951,13(1):192-196
Ohne Zusammenfassung 相似文献
55.
Dr. R. Gächter E. Szabó dipl. Chem. A. Mareš 《Aquatic Sciences - Research Across Boundaries》1971,33(1):66-72
Zusammenfassung Die Beeinflussung des Vierwaldst?ttersees (Horwer Bucht) durch den mit dem Abwasser von 10 000 Einwohnern belasteten Steinibach
liess sich im Oberfl?chenwasser auf eine Distanz von mehr als 2 km verfolgen (Abb. 1a, 1b, 1c).
Es zeigte sich, dass eine erh?hte Phosphorzufuhr eine verst?rkte biogene Nitratzehrung erm?glicht. Die Abh?ngigkeit der Pigmentkonzentration
y von der Gesamtphosphorkonzentrationx liess sich durch die folgende Mitscherlich-Gleichung beschreiben: log(30-y)=log 30–0,012 (x−6)
Damit wurde im Vierwaldst?ttersee erstmals unter v?llig natürlichen Bedingungen die Beeinflussung der Prim?rproduktion durch
eine erh?hte Phosphorkonzentration nachgewiesen (Abb. 2).
Die Erfolgsaussichten von Abwassersanierungsmassnahmen an Seen verschiedener Trophiegrade werden diskutiert.
Summary The influence of the ‘Steinibach” tributary, into which the wastewater of 10,000 inhabitants is discharged, on the Lake of Lucerne (Horwer Bucht) is detectable in the surface water over a distance of more than 2 km (Picture 1a, 1b, 1c). It was revealed that the increased phosphorus supply enables more intensive biological nitrate consumption. The dependence of the pigment concentration,y, on the total phosphorus concentration,x can be expressed by the following Mitscherlich equation: log (30−y)=log 30–0.012 (x−6). This was the first time that the influence of an increased phosphorus concentration on primary production was proved in the Lake of Lucerne under completely natural conditions (Picture 2). The possibilities of implementing successful water pollution control measures in lakes with various trophic levels are discussed.相似文献
56.
57.
F. Zebender P. Zimmermann R. Märki A. Hörler H. Ambübl 《Aquatic Sciences - Research Across Boundaries》1961,23(1):296-308
Ohne Zusammenfassung 相似文献
58.
The use of mycorrhiza for eco‐engineering measures in steep alpine environments: effects on soil aggregate formation and fine‐root development 下载免费PDF全文
Alexander Bast Wolfgang Wilcke Frank Graf Peter Lüscher Holger Gärtner 《地球表面变化过程与地形》2014,39(13):1753-1763
Steep erosion‐prone and vegetation‐free slopes are widespread in alpine areas and are often discussed since they have a high socio‐economic damage potential. We present an eco‐engineering approach to test whether a mycorrhizal inoculum improves the establishment of hedge brush layers and in turn soil structural stability on a steep, coarse‐grained vegetation‐free slope in the eastern Swiss Alps. We established (i) mycorrhizal and (ii) non‐mycorrhizal treated eco‐engineered research plots on a field experimental scale, covering a total area of approximately 1000 m2 on an east‐northeast (ENE) exposed slope, where many environmental parameters can be regarded as homogeneous. After a full vegetation period, we quantified soil aggregate stability, the formation of water stable aggregates and the fine‐root development. Our results illustrate that the establishment of brush layers without mycorrhizal inoculum increased aggregate stability significantly. Against our expectation and glasshouse experiments, the addition of mycorrhizal inoculum did not have a statistically significant effect after one vegetation period although it tended to increase aggregate stability. Analogously, root length density (RLD) tended to be higher at the non‐mycorrhizal treated site. Aggregate stability was significantly correlated with RLD. Studies on a bigger field experimental scale are inevitable, complement glasshouse studies and lead to a better understanding for a successful application of sustainable eco‐engineering measures in alpine environments. Based on our results and considering the fact that the response time in natural ecosystems may be slower than in laboratory approaches, we conclude that long‐term field studies are necessary to validate results gained through laboratory experiments. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
59.
60.
Päivi Mäntyniemi 《Journal of Seismology》2007,11(2):177-185
This study investigates the effects of the Fennoscandian earthquake that occurred on 4 November 1898 (GMT) on Tornio in Northern
Finland. The extra fire inspection conducted in the town on 21, 22 and 23 November 1898 provided insight into the failures
caused by this low-magnitude earthquake. The building stock was of timber with masonry stone components. More than 30 heating
units sustained damage. The macroseismic intensity in Tornio is estimated at I = 6 (European Macroseismic Scale). 相似文献