纤磷钙铝石类化合物:来自地球具工艺用途的材料(英文)     

Schw.  RG 《地学前缘》2000,7(2):485-497

纤磷钙铝石类化合物系由自纤磷钙铝石CaAl3 (OH) 6(HPO4) (PO4)本身、经磷钙铝石CaAl3 (OH) 6(SO4) (PO4)到钾明矾石KAl3 (OH ) 6(SO4) 2 等的天然矿物族所组成的。它们表现出具有很大范围的阳离子置换系列 ,其中以Sr2 +和Ba2 +置换Ca2 +,REEs3 +置换Ca2 +和H+,As5 +置换P5 +,S6+/Se6+置换H+P5 +最为重要。随着置换的进行 ,其热动力学稳定性也逐渐增加。由此 ,纤磷钙铝石类化合物成为很能抗风化的矿物 ,在红土中尤其如此。厚的纤磷钙铝石层形成在闪长岩 (富Sr) ,碳酸盐岩 (富REEs)和含金石英脉 (富As)之上 ,从而保护整个磷酸盐红土 ,使之免受风化。以此方式 ,形成了桌状山脉或岛屿 ,他们具有未受覆盖的表面。这些“纤磷钙铝”石化合物为上述及其它元素形成一有效的地球化学障。“纤磷钙铝石”的这种天然地球化学固定作用可以用适当的母体或人工合成晶体来进行模拟 ,即通过金属阳离子交换或就地反应来模拟。这种固定作用还可用于处理天然和人造的放射性裂变产物、有毒的重金属元素、砷酸盐和硒酸盐、硫酸盐等。  相似文献   

Socioeconomic analysis within an interdisciplinary spatial decision support system for an integrated management of the Werra River Basin   总被引：4，自引：0，他引：4  

Jesko Hirschfeld  Alexandra Dehnhardt  Jrg Dietrich 《Limnologica》2005,35(3):234-244

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On the external part of the geomagnetic secular variations ofD andH at Wingst Observatory (Erdmagnetisches Observatorium Wingst)     

Dietrich Voppel 《Ocean Dynamics》1982,35(4):169-176

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A geothermic method for the reconstruction of the uplift history of a mountain range,applied to the Central Alps     

Dr. Dietrich Werner 《International Journal of Earth Sciences》1981,70(1):296-301

Vertical movements of a crustal block in connection with denudation, sedimentation or overthrusting, respectively, lead to a change in the temperature field. This process can be used to correlate the uplift and temperature history of a rock sample in a quantitative way. The uplift rate may change over a period of time. The effect of the radiogenic heat sources has been taken into account in the calculations.For the reconstruction of the uplift history of a high mountain range, paleotemperature data for the rock (blocking temperatures) in conjunction with radiometric ages must be available.Two uplift models are presented for the Leventina/Verzasca region (Central Swiss Alps).

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Zusammenfassung Vertikalbewegungen eines Krustenblocks in Verbindung mit Erosion bzw. Sedimentation oder Deckenüberschiebung führen zu einer Veränderung des Temperaturfeldes. Dies kann benutzt werden, um die Hebungs- und Temperaturgeschichte einer Gesteinsprobe quantitativ miteinander zu verknüpfen. Dabei darf sich die Hebungsrate zeitlich ändern. Bei den Berechnungen wird der Effekt der radiogenen Wärmequellen berücksichtigt.Zur Rekonstruktion der Hebungsgeschichte eines Hochgebirges müssen Paläotemperaturen des Gesteins (Blockungstemperaturen) in Verbindung mit radiometrischen Altern vorliegen.Für das Gebiet Leventina/Verzasca (Schweizer Zentralalpen) werden zwei Hebungsmodelle vorgestellt.

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Résumé Les mouvements verticaux d'un bloc de la croûte terrestre, sous l'effet de l'érosion, la sédimentation, ou le recouvrement par des nappes conduit a des changements dans la répartition des températures. Ce processus peut être employé pour corréler quantitativement l'histoire des températures et des mouvements verticaux durant une certaine période. L'effet de la source radiogénique de chaleur est prise en considération pour le calcul.Pour la reconstruction de l'histoire des mouvements verticaux d'une zone montagneuse, les paléotempératures d'un échantillon de roche (températures de blocage) en conjonction avec les âges radiométriques doivent être données.Deux modèles présentés concernent la région de la Leventina/Verzasca (Alpes centrales de Suisse).

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Contribution no. 306 of the Institut für Geophysik, ETH Zürich.  相似文献   

Homogeneous reprocessing of GPS,GLONASS and SLR observations   总被引：3，自引：2，他引：1  

Mathias Fritsche  Krzysztof Sośnica  Carlos Javier Rodríguez-Solano  Peter Steigenberger  Kan Wang  Reinhard Dietrich  Rolf Dach  Urs Hugentobler  Markus Rothacher 《Journal of Geodesy》2014,88(7):625-642

The International GNSS Service (IGS) provides operational products for the GPS and GLONASS constellation. Homogeneously processed time series of parameters from the IGS are only available for GPS. Reprocessed GLONASS series are provided only by individual Analysis Centers (i. e. CODE and ESA), making it difficult to fully include the GLONASS system into a rigorous GNSS analysis. In view of the increasing number of active GLONASS satellites and a steadily growing number of GPS+GLONASS-tracking stations available over the past few years, Technische Universität Dresden, Technische Universität München, Universität Bern and Eidgenössische Technische Hochschule Zürich performed a combined reprocessing of GPS and GLONASS observations. Also, SLR observations to GPS and GLONASS are included in this reprocessing effort. Here, we show only SLR results from a GNSS orbit validation. In total, 18 years of data (1994–2011) have been processed from altogether 340 GNSS and 70 SLR stations. The use of GLONASS observations in addition to GPS has no impact on the estimated linear terrestrial reference frame parameters. However, daily station positions show an RMS reduction of 0.3 mm on average for the height component when additional GLONASS observations can be used for the time series determination. Analyzing satellite orbit overlaps, the rigorous combination of GPS and GLONASS neither improves nor degrades the GPS orbit precision. For GLONASS, however, the quality of the microwave-derived GLONASS orbits improves due to the combination. These findings are confirmed using independent SLR observations for a GNSS orbit validation. In comparison to previous studies, mean SLR biases for satellites GPS-35 and GPS-36 could be reduced in magnitude from \(-35\) and \(-38\)  mm to \(-12\) and \(-13\)  mm, respectively. Our results show that remaining SLR biases depend on the satellite type and the use of coated or uncoated retro-reflectors. For Earth rotation parameters, the increasing number of GLONASS satellites and tracking stations over the past few years leads to differences between GPS-only and GPS+GLONASS combined solutions which are most pronounced in the pole rate estimates with maximum 0.2 mas/day in magnitude. At the same time, the difference between GLONASS-only and combined solutions decreases. Derived GNSS orbits are used to estimate combined GPS+GLONASS satellite clocks, with first results presented in this paper. Phase observation residuals from a precise point positioning are at the level of 2 mm and particularly reveal poorly modeled yaw maneuver periods.  相似文献   

Influence of source thickness on steady-state plume length     

P. K. Yadav  R. Liedl  P. Dietrich 《Environmental Earth Sciences》2014,71(2):959-964

The impact of source thickness on steady-state plume length is studied using modifications of the analytical expressions provided in Liedl et al. (2005, 2011) for 2D and 3D scenarios. For comparison, 2D and 3D numerical experiments were performed, and the following three important conclusions were obtained: first, the modified expressions overestimate the plume length only up to a factor of 2 when the source thickness (M _s ) is at least 50 % of the aquifer depth (M). Second, overestimates do not exceed plume length by a factor of 10 (2D scenario) or 5 (3D scenario) for 25 % < M _s /M < 50 %. Third, numerical techniques are recommended for M _s  < 25 %. In addition, it was observed that the degradation from the top dominates for M _s /M > 50 %. As far as the numerical experiments are concerned, it is important to note that the employed finite element approach was applied to the transformed transport equation provided in both Liedl et al. works. This transformation, which can also be applied to more complex scenarios than those studied here, eliminates reaction terms from the model equations and therefore largely facilitates numerical computations.  相似文献