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11.
The total ionizing component of cosmic radiation was measured up to an altitude of 1550 km. An upper bound to the ratio of average-to-minimum specific ionization was determined by comparing the ionization with the count-rate observations from the Explorer IV satellite. This result implied that protons are the predominant species which gave rise to the observed ionization.  相似文献   
12.
The work is dedicated to most important abiotic processes of the Early Precambrian, effect of which is recorded in continental crust, and to complementary processes in subcontinental mantle. We intend to figure out when a certain process was triggered first in the past and what indications suggest its further activity, evolution and possible cessation in subsequent geological history. Considerations are based on described natural objects characterizing particular geological events and enabling the cause-and-effect interpretation in order to understand different viewpoints known from publications. Considered in the work are the early Precambrian greenstone belts and ophiolites, island-arc systems and ecologites, magmatism unconnected with subduction zones (rifting-related, plateau basalts, dykes, kimberlites) and anorthosites representing a group of heterochronous intrusions of complicated genesis. Main considerations are premised with a brief review of the earliest geodynamic phenomena associated with meteorite impacts by termination of the planetary accretion.  相似文献   
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Control strategies for the Clam Wave Energy Device   总被引:1,自引:0,他引:1  
A promising wave energy device being currently investigated is the ‘clam’. The clam extracts energy by pumping air through a specially designed (Wells) turbine. Although operation of the Wells turbine does not require a rectified air flow, some additional control will be necessary to optimize the phase of the clam motion for good efficiencies. An examination of the equation of motion in the time domain suggests the possibility of phase control by mechanical, power take-off, or pneumatic latching. Latching can be shown to increase the efficiency of the device in the longer wavelengths of the wave spectrum, i.e. those of high incident wave power. Equivalently latching could be used to keep the device efficiency high while reducing its size, possibly resulting in cheaper power extraction.  相似文献   
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In 2004, McLaughlin et al. discovered a phenomenon in the radio emission of PSR J0737−3039B (B) that resembles drifting subpulses. The repeat rate of the subpulses is equal to the spin frequency of PSR J0737−3039A (A); this led to the suggestion that they are caused by incidence upon B's magnetosphere of electromagnetic radiation from A. Here, we describe a geometrical model which predicts the delay of B's subpulses relative to A's radio pulses. We show that measuring these delays is equivalent to tracking A's rotation from the point of view of a hypothetical observer located near B. This has three main astrophysical applications: (i) to determine the sense of rotation of A relative to its orbital plane, (ii) to estimate where in B's magnetosphere the radio subpulses are modulated and (iii) to provide an independent estimate of the mass ratio of A and B. The latter might improve existing tests of gravitational theories using this system.  相似文献   
17.
Soils in New Zealand, and elsewhere, often contain substantial zones of ferro-manganese concretions and pans (laterally continuous layers) that can affect soil quality and management. Soils containing concretions and pans from Southland, New Zealand, were investigated to determine links between microbial ecology and geochemistry. Three soil profiles were sampled at 100-mm intervals to a depth of 1 m and then assayed for nine different populations of bacteria using selective media. Geochemical analysis was performed on the soils at the same intervals, and on shallow groundwater from nearby wells. The largest concentrations of iron (Fe) and manganese (Mn) coincide with concretions. Nitrogen (N) and carbon (C) are not correlated with Fe and Mn but may be depleted due to bacterial metabolism. Fe and Mn concentrations in groundwater are low, suggesting that the source of these elements in the concretions and pans is in situ weathering rather than groundwater. Numbers of iron oxidising organisms increase where concretions and pans are encountered, but manganese-oxidising organisms decrease. Heterotrophic, sulphur-oxidising, and anaerobic populations have relatively consistent numbers at all depths within the profiles. Fifty organisms were selected for phylogenetic characterisation, of which only Pseudomonas sp. is known to have significant interactions with Fe and Mn. These results suggest a link between concretion development and iron-oxidising microbial populations.  相似文献   
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Unlined rock caverns for oil storage are very common in Sweden. Most of them are excavated in hard rocks (compact, non-carbonate, non-volcanic rocks). The fundamental idea of underground oil storage is that the rock caverns are located below the natural ground water level. Hereby the ground water keeps the oil inside the caverns and prevents products migration.

During the excavating period the water seeping through the fractures of a cavern is pumped up to avoid flooding. This discharge causes a local drop in the ground-water level around the cavern and a cone of depression develops.

A local study of the development of such a cone of depression has been made by means of a network of observation holes around the cavern. On enlargement of an oil storage (by constructing new caverns close to the old ones), the cone of depression moves according to the progress of the new excavations. This process has been studied and described in two cases.

Underground storages in Sweden are very often closely spaced in order to use common facilities such as entrance tunnel, pumping station, housing etc. Therefore an artificial ground-water divide sometimes must be arranged between different caverns in order to prevent products migration. This paper describes how such an artificial recharge of water between some caverns is made. The control of its effectiveness is shown as well as the method for sealing off undesirable leakage.  相似文献   

20.
Geological, petrochemical, and geochemical data are presented on metacarbonate rocks (calciphyres) of the Lapland—Kolvitsa granulite belt, Baltic Shield. The normative mineral composition of source rocks of the studied calciphyres was first reconstructed. High contents of some indicator elements (Fe, Mn, Cr, Co, P, Pb, and others) suggest that material supplied to the paleobasin was derived from diverse rocks (ultramafic, mafic, intermediate, and felsic). Contents and correlations of some trace elements (Sr, Li, F, Ba, and others) indicate that primary sediments formed under humid-semihumid paleoclimate in a fresh-water paleobasin (lagoon) characterized by occasional increase in salinity.  相似文献   
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