The experimental investigation of the reactions MnCO3+SiO2=MnSiO37#x002B;CO2 and MnSiO3+MnCO3=Mn2SiO4+CO2 in CO2/H2O gasmixtures at a total pressure of 500 bars     

M. A. F. Candia  Tj. Peters  J. V. Valarelli 《Contributions to Mineralogy and Petrology》1975,52(4):261-266

The equilibrium constants for the reaction (2) Rhodochrosite + Quartz=Pyroxmangite+CO₂ obtained are:logK(₂)(bars)= $$\begin{gathered}{\text{log}}f_{co_2 } = - \frac{{(9862 \pm 102)}}{T} \hfill \\+ (15.887 \pm 0.220) + (0.1037 \pm 0.0020)\frac{{P - 1}}{T} \hfill \\\end{gathered} $$ and for the reaction (3) Rhodochrosite+Pyroxmangite=Tephroite+CO₂: logK(₃)(bars)= $$\begin{gathered}{\text{log}}f_{co_2 } = - \frac{{(6782 \pm 205)}}{T} \hfill \\+ (11.296 \pm 0.304) + (0.0835 \pm 0.0030)\frac{{P - 1}}{T} \hfill \\\end{gathered} $$ The present data lie within reasonable limits of error of the values calculated from previous experimental results at P _tot = 2000 bars.  相似文献   

Addendum to “Effects of sea roughness and atmospheric stability on wind wave growth”     

Dag Myrhaug  Olav H. Slaattelid 《Ocean Engineering》2003,30(8):1079-1082

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A note on a theoretical model of oscillatory smooth turbulent boundary layers     

Dag Myrhaug 《Ocean Engineering》1984,11(3):315-320

An analytical theory which describes the motion in an oscillatory smooth turbulent boundary layer using a two-layer time invariant eddy viscosity model is presented. The eddy viscosity in the inner layer increases quadratically with the height above the wall. In the outer layer the eddy viscosity is taken as a constant.  相似文献   

Rapid physicochemical changes in the high Arctic Lake Kongressvatn caused by recent climate change     

Trine Marianne Holm  Karin A. Koinig  Tom Andersen  Espen Donali  Anne Hormes  Dag Klaveness  Roland Psenner 《Aquatic Sciences - Research Across Boundaries》2012,74(3):385-395

High Arctic lakes are among the most sensitive ecosystems and climate change strongly affects their physical properties, especially water temperature, and mixing processes. To study the effect of recent climate change on such a lake in the Arctic environment, we measured water chemistry and temperature from 2005 to 2010 in Kongressvatn, a crenogenic meromictic lake in Spitsbergen (Svalbard). In addition, we monitored water column temperatures during two consecutive years and compared them to regional air temperature data and physicochemical lake data from 1962 and 1968, two relatively cold years. Summer surface water temperature was highly correlated to air temperature, and both have increased by approximately 2°C since 1962. Temperature monitoring during 2?years showed that the warm summer of 2007 resulted in increased water temperatures even in the stratified, denser hypolimnion. Our water chemistry measurements showed that the chemocline position in 2005?C2010 was ca 12?m deeper than in 1962?C1968, and a second, weaker, chemocline appeared at metalimnetic depths of 7?C15?m. During the study period, the water level decreased by 4?m, and this change accelerated between 2008 and 2010. Our data support the hypothesis that water temperatures and stratification patterns are changing rapidly with air temperature, but changes in the catchment, such as glacial retreat and permafrost melting, may have an even stronger impact on lake properties.  相似文献   

前陆盆地的三维挠曲数值模拟: 以怀俄明西南上白垩统研究为例     

Hongjun Luo  Dag Nummedal  Shaofeng Liu 《地学前缘》2010,17(4):128-139

前陆盆地的三维挠曲数值模拟是预测盆地三维格架和关键构造要素分布的强有力工具, 如在预测前隆分布方面(低隆起幅度、大范围分布的前隆很难从地下资料中识别)。为了解释详细地层对比中发现的前隆迁移,对怀俄明西南晚白垩世前陆盆地做了三维挠曲数值模拟。模拟过程中采用弹性地壳模型,并以详细的年代地层资料作为基本的输入数据。挠曲负载的估计来源于公开发表的怀俄明逆冲带的横剖面资料和风河逆冲带的缩短速率。模拟结果表明,由于逆冲负载的分布,前隆只局限分布在盆地的南部。随负载的迁移,前隆随时间向东南方向迁移。由于怀俄明逆冲带和风河逆冲带的相互作用,弹性地壳形成三维“前缘穹隆”而不是二维“前缘隆起”。三维挠曲模拟是理解怀俄明西南晚白垩世前隆迁移的关键。  相似文献   

Rippled scour depressions on continental shelf bank slopes off Nordland and Troms,Northern Norway     

Valérie K. Bellec  Reidulv Bøe  Leif Rise  Dag Slagstad  Oddvar Longva  Margaret F.J. Dolan 《Continental Shelf Research》2010

Multibeam bathymetry acquired under the MAREANO programme from the continental shelf off Nordland and Troms, northern Norway, show bedforms that we have interpreted as rippled scour depressions. They occur in three areas offshore on bank slopes facing southeast, more than 15 km from land. They are generally found where the slope gradient is low, in water depths of 70–160 m. Individual depressions are up to 3 km long, 1 m deep and up to 300 m wide. They occur in areas where sediments evolve quickly from glacial deposits on the banks to post-glacial muddy sediments on the glacial troughs. Multibeam backscatter and underwater video data show that depression floors are covered by rippled, gravelly, shelly sand. Ripple crests are parallel or slightly oblique to the depression axis orientation. Sand without bedforms is observed between the depressions. TOPAS seismic lines show that the uppermost seismic unit consists of the sand between the depressions. The base of this unit may be the last transgressive/tidal/wave ravinement surface. Physical oceanographic modelling indicates that maximum current velocities are up to 0.6 m/s in the rippled scour depression areas. Stronger currents appear to inhibit the building of these features. Tidal currents play an important role as they trend parallel to the southeast banks slopes and are likely responsible of the gravelly ripples formation inside the depressions as well as the persistence of these depressions which are not covered by finer sediments. On Malangsgrunnen bank, some of the rippled scour depressions are in the extension of NW–SE furrows located on the bank. Simulated bottom currents indicate currents mainly perpendicular to these furrows, as for the rippled scour depressions on the bank slopes. Nevertheless, these features could also highlight currents coming from the northwest which reach the bank margin and continue down to the areas of the rippled scour depressions. These currents could be responsible for the formation of some of the bedforms, together with tidal currents.  相似文献   

The year-long unprecedented European heat and drought of 1540 – a worst case     

Oliver Wetter  Christian Pfister  Johannes P. Werner  Eduardo Zorita  Sebastian Wagner  Sonia I. Seneviratne  Jürgen Herget  Uwe Grünewald  Jürg Luterbacher  Maria-Joao Alcoforado  Mariano Barriendos  Ursula Bieber  Rudolf Brázdil  Karl H. Burmeister  Chantal Camenisch  Antonio Contino  Petr Dobrovolný  Rüdiger Glaser  Iso Himmelsbach  Andrea Kiss  Oldřich Kotyza  Thomas Labbé  Danuta Limanówka  Laurent Litzenburger  Øyvind Nordl  Kathleen Pribyl  Dag Retsö  Dirk Riemann  Christian Rohr  Werner Siegfried  Johan Söderberg  Jean-Laurent Spring 《Climatic change》2014,125(3-4):349-363

The heat waves of 2003 in Western Europe and 2010 in Russia, commonly labelled as rare climatic anomalies outside of previous experience, are often taken as harbingers of more frequent extremes in the global warming-influenced future. However, a recent reconstruction of spring–summer temperatures for WE resulted in the likelihood of significantly higher temperatures in 1540. In order to check the plausibility of this result we investigated the severity of the 1540 drought by putting forward the argument of the known soil desiccation-temperature feedback. Based on more than 300 first-hand documentary weather report sources originating from an area of 2 to 3 million km², we show that Europe was affected by an unprecedented 11-month-long Megadrought. The estimated number of precipitation days and precipitation amount for Central and Western Europe in 1540 is significantly lower than the 100-year minima of the instrumental measurement period for spring, summer and autumn. This result is supported by independent documentary evidence about extremely low river flows and Europe-wide wild-, forest- and settlement fires. We found that an event of this severity cannot be simulated by state-of-the-art climate models.  相似文献   

Erratum to: The year-long unprecedented European heat and drought of 1540 – a worst case     

Oliver Wetter  Christian Pfister  Johannes P. Werner  Eduardo Zorita  Sebastian Wagner  Sonia I. Seneviratne  Jürgen Herget  Uwe Grünewald  Jürg Luterbacher  Maria-Joao Alcoforado  Mariano Barriendos  Ursula Bieber  Rudolf Brázdil  Karl H. Burmeister  Chantal Camenisch  Antonio Contino  Petr Dobrovolný  Rüdiger Glaser  Iso Himmelsbach  Andrea Kiss  Oldřich Kotyza  Thomas Labbé  Danuta Limanówka  Laurent Litzenburger  Øyvind Nordli  Kathleen Pribyl  Dag Retsö  Dirk Riemann  Christian Rohr  Werner Siegfried  Johan Söderberg  Jean-Laurent Spring 《Climatic change》2014,125(3-4):365-367

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Biochemical biomarkers in adult female perch (Perca fluviatilis) in a chronically polluted gradient in the Stockholm recipient (Sweden)     

Hansson T  Schiedek D  Lehtonen KK  Vuorinen PJ  Liewenborg B  Noaksson E  Tjärnlund U  Hanson M  Balk L 《Marine pollution bulletin》2006,53(8-9):451-468

A battery of biochemical biomarkers and the SigmaPCB concentration in adult female perch (Perca fluviatilis) verified an aquatic pollution gradient with the city of Stockholm (Sweden) as a point source of anthropogenic substances. The investigation included both an upstream gradient, 46 km westwards through Lake M?laren, and a downstream gradient, 84 km eastwards through the Stockholm archipelago. Besides the main gradient from Stockholm, there were strong indications of pollution coming from the Baltic Sea. The results indicated a severe pollution situation in central Stockholm, with poor health status of the perch, characterised by increased specific EROD activity in the liver, increased liver EROD somatic index, decreased AChE activity in the muscle, increased amount of DNA adducts in the liver, and a high concentration of biliary 1-pyrenol. In addition, laboratory exposure to common EROD inducers elicited an abnormal response, suggestive of chronic intoxication.  相似文献