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31.
Summary The primary scattering of atmospheric haze is computed by modification of an approximative method evolved byde Bary, basing on skylight measurements carried out on the Musalla, a mountain of 3000 m height in Bulgaria, at various altitudes of the sun and in different horizontal circles at a wavelength of 450 nm. This measured total radiation is reduced by the radiation induced by the scattering at molecules as well as by secondary or multiple scattering at turbidity aerosol. The single scattering of the atmospheric haze thus computed is discussed for various assumed Linke turbidity factors.The concluding deductions relate to a comparison of haze scattering functions with theoretical scattering functions, the results attained agreeing closely with superimposed logarithmic Gaussian distributions and only partly with the scattering functions computed byBullrich. These deductions prove optically the increase of larger particles (r 00.64 m) during forenoon. The analysis of the scattering functions conductes to a shortage of particles withr 0=0.2 m in agreement with other investigations.
Zusammenfassung In Abwandlung einer vonde Bary angegebenen Approximationsmethode wird die Primärstreuung des atmosphärischen Dunstes berechnet. Zugrundegelegt werden Himmelsllichtmessungen, die auf dem etwa 3000 m hohen Mus Alla in Bulgarien bei verschiedenen Sonnenhöhen und in verschiedenen Horizontalkreisen bei einer Wellenlänge von 450 nm durchgeführt wurden. Von dieser gemessenen Gesamtstrahlung werden die Anteile substrahiert, die durch Streuung an Molekülen sowie durch zwei-oder mehrfache Streuung an Trübungsaerosol hervorgerufen werden. Die so berechnete Einfachstreuung des atmosphärischen Dunstes wird für verschiednee angenommene Linke'sche Trübungsfaktoren diskutiert.Abschließend werden die Dunststreufunktionen mit theoretischen Streufunktionen verglichen, wobei eine gute Übereinstimmung mit überlagerten logarithmischen Gauß-Verteilungen und nur teilweise mit vonBullrich berechneten Streufunktionen erzielt wurde. Es kann dabei optisch die Zunahme großer Teilchen (r 00,64 m) im Laufe des Vormittags gezeigt werden. Die Analyse der Streufunktionen führt zu einem Fehlen von Teilchen mitr 0=0,2 m in Übereinstimmung mit anderen Untersuchungen.
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32.
Morphogenetic problems of the upper Huang He drainage Basin   总被引:2,自引:0,他引:2  
The combination of meanders, deep gorges, and transverse cuttings is considered as the main geomorphogenetic feature of the upper Huang He. The belonging landforms reveal remnants of former landsurfaces which appear as plateau flats, summit levels, and rock-cut valley terraces. They are interpreted as relics of planation surfaces, pediments, and valley bottoms. The most widespread remnants are the plateau flats, situated at altitudes between about 4,200 and 4,600 m asl. They are named as Main Surface, the other remnants related to it as Pre I-Surface and as Post I-to III-Levels respectively. The planation levels are connected with the stages of the Cenozoic tectonic evolution of the Tibetan Plateau. The upper Huang He drainage pattern is preliminarily explained by an antecedent development of seperate valley units.  相似文献   
33.
The solubility of wollastonite in chloride solutions has been measured between 750° C and 850° C at 2kb pressure and at 800°C at 1 kb pressure. The fugacity of HCl at P and T was controlled by combining Ag+AgCl internally with magnetite +hematite+water as an external hydrogen buffer. Silica activity was fixed by the presence of quartz. The calcium and chloride contents of the solutions were measured after quench. CaCl2 appears to be the major solute species.Using these compositional data, the Gibbs Free Energy of formation for CaCl2 was calculated, assuming that the activity coefficient quotient is near unity. The results were combined with quartz solubility data and calculations made by Joesten (1974) to approximate the compositions of CO2-H2O rich fluids which prevailed during the metasomatic formation of mono-minerallic zones in calc-silicate nodules from a contact aureole in the Christmas Mountains, Texas. The largest predicted gradients in H4SiO4 and CaCl2 occur across the wollastonite zone.  相似文献   
34.
Zusammenfassung Ca. 70 — mit wenigen Ausnahmen orientiert im Gelände bzw. unter Tage entnommene — Gesteinsproben wurden bei einer Temperatur von ca. 94° C und Atmosphärendruck auf ihre Wärmeleitfähigkeiten in verschiedenen Richtungen untersucht. Insgesamt wurden einschließlich der Wiederholungsmessungen ca. 500 Einzelmessungen der Wärmeleitfähigkeit durchgeführt. Bei den untersuchten Proben handelt es sich zum großen Teil um Tonschiefer aus dem Rheinischen Schiefergebirge und dem Harz, zum kleineren Teil um Kalksteine aus dem Rheinischen Schiefergebirge, Metamorphite aus den Ostalpen und anderen Gebieten sowie um einige Magmatite.Bei den meisten untersuchten Proben, insbesondere denen mit schon äußerlich erkennbaren Planar- und Lineartexturen, sind die Wärmeleitfähigkeiten streng richtungsabhängig; diese Proben sind bezüglich der Wärmeleitfähigkeit (und anderer gesteinsphysikalischer Eigenschaften) anisotrop. Die Meßergebnisse werden in den Tabellen 2 bis 5 vorgestellt.
The heat conductivities of some 70 oriented rock specimens taken from the field or subsurface were determined in various directions at about 94° C and atmospheric pressure. Some 500 individual measurements, duplicate measurements included, were carried out.The majority of the tested samples are slates from the Rheinische Schiefergebirge and the Harz (Rhenoherzynikum), a minor portion is made up of limestones from the Rheinische Schiefergebirge, metamorphic rocks from the central Eastern Alps and some other areas, and only some magmatic rocks were tested for comparison. The results of the heat conductivity measurements are presented in the tables 2–5.In most of the rocks investigated, especially in those showing planar and linear textures at the mesoscale, the heat conductivity is strongly controlled by the direction of measurement. These rocks are anisotropic with respect to the heat conductivity (and to other physical rock properties as well).The measurements of the heat conductivity in slates from the Rheinische Schiefergebirge showed considerable differences in different directions of the rock samples. In those slates, containing a transverse (slaty) cleavage (s1) besides the bedding planes (ss) (the typical roofing slates, e g.), the plane of the slaty cleavage turns out to be the best heat insulator, i. e., the direction of the least heat conductivity of the whole rock (k33) is oriented normally to s1 The direction of the greatest heat conductivity (k11 of these rocks lies within the plane of s1 and parallel to the intersection line of ss and s1, or parallel to the Faser (longrain), a lineation down dip of the slaty cleavage planes, only in some regionally restricted areas. The direction of the mean conductivity (k22) is oriented normally to k11 in the plane of s1. The anisotropy of heat conductivity in these slates (as well as in the mica schists and gneisses investigated) shows a orthorhombic symmetry. The tensor of the heat conductivity for these rocks, referred to the main axes, has the formIn other slates, or better shales in the cases concerned, from the upper part of the Rhenohercynian sedimentary column, lacking any transverse cleavage at the mesoscale and rearrangements and new crystallization of the phyllosilicate minerals at the microscale, the bedding plane (ss) turns out to be the best heat insulator. Consequently, the direction of least heat conductivity (k33) in these rocks is normal to the bedding plane (ss). Within the bedding plane there is no preferred direction of heat conductivity (k11 = k22 > k33). Both slate types differing with respect to the anisotropy of heat conductivity with k33 s1 and k33 ss, resp., are linked by transitional stages.The results of heat conductivity measurements in slates from different tectonic frameworks (tectonic environments) of the Rhenoherzynikum presented here, reflect — in an indirect way — the various finite stages of the progressive fabric development within a relatively shallow orogen such as the Rheinische Schiefergebirge and the Harz, according to the author (Langheinrich 1964, 1976, 1978).Measurements of the heat conductivity of limestones from the Rheinische Schiefergebirge showing marked evidence of finite internal tectonic deformation demonstrated that these rocks are isotropic with regard to heat conductivity, presumably as a result of posttectonic annealing recrystallization of the rock forming calcite.Within the mica-schists and gneisses investigated the heat conductivity is always at a minimum normal to the s-planes (foliation) of these rocks, and at a maximum within the s-planes, mostly parallel to a lineation at mesoscale. Within this group of rocks the highest (k11) and lowest heat conductivity (k33) can differ by a factor of nearly 3 (table 4).All specimens of magmatites, only measured for comparison, showed near-perfect isotropy of heat conductivity.The whole-rock anisotropy of heat conductivity — considered under the conditions of experiment — is controlled by a number of factors. But the essential factors controlling this strong whole-rock anisotropy of the slates, mica-schists, and gneisses are the presence in considerable amounts of rock forming minerals with high individual anisotropies of heat conductivity, and the statistically preferred orientation of these minerals.The phyllosilicate minerals illite/muscovite with an anisotropy factor (k11/k33) of about 6 and chlorite (with a presumably similar anisotrop factor) play a major part. Quartz which shows some preferred crystal lattice orientation in some cases only plays a subordinate role with respect to the whole-rock anisotropy of heat conductivity. The anisotropy factor of quartz is about 1.7 (at room temperature).The statistically preferred orientation of some crystal lattices of the rock forming minerals with high individual anisotropies of heat conductivity was studied for a series of representative specimens of slates using a X-ray texture goniometer. The X-ray studies revealed excellent geometric correlations between the symmetries of the X-ray textures and the anisotropy of heat conductivity.Some 50 specimens of slates were selected for measurements of the propagation velocity of longitudinal ultrasonic pulses in various directions. Here, a perfect geometric correlation of the anisotropy of heat conductivity and the elastic anisotropy was found.Comparisons of the degree of crystallinity of illite and the anisotropy of heat conductivity in some slate specimens revealed no clear-cut correlation of these two parameters (see table 2).Before extending the data of heat conductivity and anisotropy of heat conductivity of rocks, determined under laboratory conditions, to in situ conditions a number of correction factors must be taken into account. These correction factors involve temperature conditions, the porosity of rocks, the kind of the pore fluids, the crack content (again a function of the stress conditions in situ), and others.

Résumé Près de 70 échantillons de roches pris sur le terrain ou en subsurface, et orientés sauf quelques exceptions, ont été examinés en vue de leurs conductibilités thermiques dans des directions différentes à une température de 94° C et à pression atmosphérique. En tout 500 mesures individuelles de conductibilité thermique ont été exécutées, y compris les mesures doubles. Les échantillons examinés sont pour la plupart des schistes argileux du Massif Schisteux Rhénan et du Harz, le reste provient de calcaires du Massif Schisteux Rhénan, de métamorphites des Alpes orientales et d'autres régions, ainsi que quelques magmatites.Les conductibilités thermiques de la plupart des échantillons examinés, surtout de ceux qui montrent des textures planaires et linéaires déjà reconnaissables à l'extérieur, dépendent strictement de la direction; ces roches sont anisotropes du point de vue de la conductibilité thermique (ainsi que d'autres caractères physiques de roches). Les résultats des mesures sont présentés dans les tableaux 2 à 5.

. (70 ) 94 . , , 500 . , , , . , , , ; — — . (2–5).
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35.
Thermal analysis of the halite liquidus in the system NaCl-H2O has been conducted for NaCl mole fractions (XNaCl) greater than 0.25 (i.e., > 50 wt. % NaCl) at pressures between 0.3 and 4.1 kb and temperatures greater than 450°C. The position of the liquidus was located by differential thermal analysis (DTA) of cooling scans only, as heating scans did not produce definitive DTA peaks. The dP/dT slope of the liquidus is positive and steep at high pressures, but at high XNaCl, and pressures below 0.5 kb it appears to reverse slope and intersects the three-phase curve (liquid-halite-vapour) at a shallow angle. However, due to the complex nature of the DTA signal when P <- 0.5 kb, there is considerable doubt about exactly what event has been recorded in the experiments conducted at these low pressures.The solubility of halite can be expressed as a function of the mole-fractional-based activity of NaCl in the liquid phase (L) in temperature (T, °K) and pressure (P, bars) In αNaCl(L.T.P) = ?19.884 ? 0.001275T ? 1388T + 3.2305 In (T) ? 0.07574PT Our liquidus data (based on 10 compositions) above 500 bars for these brines were combined with this equation to generate activity coefficients of NaCl which were fit within their experimental uncertainties to the following one parameter Margules equation In γNaCl(L.T.P) = (0.7268 ? 695.7T ? 0.1217PT)(1 ? XNaCl)2. Concentrated solutions of NaCl show negative deviations from ideality which rapidly increase in magnitude with decreasing XNaCl.  相似文献   
36.
同位素地质年代学及在地质学中的应用(英文)   总被引:2,自引:0,他引:2  
Faure  G 《地学前缘》1998,5(1):17-39
一些元素(K,Rb,Re,Sm,Lu,U和Th)的自然长寿命放射性同位素,衰变为另种元素稳定同位素的作用,广泛应用于岩石和矿物的年龄测定。这种测年提供了关于地球地质历史的信息,并已用于标定地质年代表。同位素测年的物理原理并不难理解,但所需要的测定技术,则要求同位素地球化学家利用地质人员采集的样品进行熟练精细的操作。对测年结果的解释也应由双方合作进行,并且在很大程度上依靠区域和地区的地质信息。笔者只介绍最广泛应用于测定岩浆岩和变质岩年龄的同位素方法,其余的一些方法只一提而过,详见同位素地质年代学专著  相似文献   
37.
We present a combined approach for the realization of the (quasi-)geoid as a height reference surface and the vertical reference surface at sea (chart datum). This approach, specifically designed for shallow seas and coastal waters, provides the relation between the two vertical reference surfaces without gaps down to the coast. It uses a regional hydrodynamic model, which, after vertical referencing, provides water levels relative to a given (quasi-)geoid. Conversely, the hydrodynamic model is also used to realize a (quasi-)geoid by providing corrections to the dynamic sea surface topography, which are used to reduce radar altimeter-derived sea surface heights to the (quasi-)geoid. The coupled problem of vertically referencing the hydrodynamic model and computing the (quasi-)geoid is solved iteratively. After convergence of the iteration process, the vertically referenced hydrodynamic model is used to realize the chart datum. In this way, consistency between the chart datum and (quasi-)geoid is ensured. We demonstrate the feasibility and performance of this approach for the Dutch mainland and North Sea. We show that in the Dutch part of the North Sea, the differences between modeled and observed instantaneous and mean dynamic sea surface topography is 8–10 and 5.8 cm, respectively. On land, we show that the methodology provides a quasi-geoid which has a lower standard deviation (SD) than the European Gravimetric Geoid 2008 (EGG08) and the official Netherlands quasi-geoid NLGEO2004-grav when compared to GPS-levelling data. The root mean square at 81 GPS-levelling points is below 1.4 cm; no correction surface is needed. Finally, we show that the chart datum (lowest astronomical tide, LAT) agrees with the observed chart datum at 92 onshore tide gauges to within 21.5 cm (SD).  相似文献   
38.
Secondary calcite residing in open cavities in the unsaturated zone of Yucca Mountain has long been interpreted as the result of downward infiltration of meteoric water through open fractures. In order to obtain information on the isotopic composition (δD and δ18O) of the mineral-forming water we studied fluid inclusions from this calcite. Water was extracted from inclusions by heated crushing and the δD values were measured using a continuous-flow isotope-ratio mass spectrometry method. The δ18O values were calculated from the δ18O values of the host calcite assuming isotopic equilibrium at the temperature of formation determined by fluid-inclusion microthermometry.The δD values measured in all samples range between ? 110 and ? 90‰, similar to Holocene meteoric water. Coupled δ18O–δD values plot significantly, 2 to 8‰, to the right of the meteoric water line. Among the various processes operating at the topographic surface and/or in the unsaturated zone only two processes, evaporation and water–rock exchange, could alter the isotope composition of percolating water. Our analysis indicates, however, that none of these processes could produce the observed large positive δ18O-shifts. The latter require isotopic interaction between mineral-forming fluid and host rock at elevated temperature (>100 °C), which is only possible in the deep-seated hydrothermal environment. The stable isotope data are difficult to reconcile with a meteoric origin of the water from which the secondary minerals at Yucca Mountain precipitated; instead they point to the deep-seated provenance of the mineral-forming waters and their introduction into the unsaturated zone from below, i.e. a hypogene origin.  相似文献   
39.
This paper presents new ideas on sampling design and minimax prediction in a geostatistical model setting. Both presented methodologies are based on regression design ideas. For this reason the appendix of this paper gives an introduction to optimum Bayesian experimental design theory for linear regression models with uncorrelated errors. The presented methodologies and algorithms are then applied to the spatial setting of correlated random fields. To be specific, in Sect. 1 we will approximate an isotropic random field by means of a regression model with a large number of regression functions with random amplitudes, similarly to Fedorov and Flanagan (J Combat Inf Syst Sci: 23, 1997). These authors make use of the Karhunen Loeve approximation of the isotropic random field. We use the so-called polar spectral approximation instead; i.e. we approximate the isotropic random field by means of a regression model with sine-cosine-Bessel surface harmonics with random amplitudes and then, in accordance with Fedorov and Flanagan (J Combat Inf Syst Sci: 23, 1997), apply standard Bayesian experimental design algorithms to the resulting Bayesian regression model. Section 2 deals with minimax prediction when the covariance function is known to vary in some set of a priori plausible covariance functions. Using a minimax theorem due to Sion (Pac J Math 8:171–176, 1958) we are able to formulate the minimax problem as being equivalent to an optimum experimental design problem, too. This makes the whole experimental design apparatus available for finding minimax kriging predictors. Furthermore some hints are given, how the approach to spatial sampling design with one a priori fixed covariance function may be extended by means of minimax kriging to a whole set of a priori plausible covariance functions such that the resulting designs are robust. The theoretical developments are illustrated with two examples taken from radiological monitoring and soil science.  相似文献   
40.
Quantitative analyses of aqueous phases and gaseous phases, gas flow rates, aqueous flow rates have been performed at twenty-five hydrothermal springs at Yellowstone National Park. Material balance calculations indicate that the inventory of argon and nitrogen in these features can be explained very well in terms of a ground water distillation model. The average rate for the release of nitrogen by both phases is 9.06 micromoles of nitrogen per mole of water discharged, and the average rate of release of argon by both phases is 0.248 micromoles of argon per mole of solution. A Rayleigh type distillation is considered in these calculations, and the distribution of argon and nitrogen between the aqueous and gaseous phases approaches equilibrium in most of the features. It is noted that these data are valid for these samples only at the time of emergence. There is no evidence for the addition of juvenile argon or nitrogen to the atmosphere by these springs at the present.  相似文献   
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