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Modifications, resulting in increased simplicity and ruggedness, have been made to the design of a micro-erosion meter to permit it to be used under water by SCUBA divers. In its modified form the instrument has been used successfully in a study measuring rates of nearshore erosion in overconsolidated glacial till.  相似文献   
104.
Ag, Al, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Zn concentrations and 210Po and 210Pb activities were measured in 26 specimens of the squid Nototodarus gouldi taken from the waters of Bass Strait in one jigging operation. All the elements show wide ranges in concentrations in specimens apparently subject to the same environmental conditions. Copper concentration was 27-1 200 μg/g, and 210Po activity 4·8–24·2 Bq/g. The animal wet weights, the elements Ag, Al, Cd, Fe and Zn, and the radionuclide 210Po have coefficients of variation in the range 40–60%; Ca, Mg and Mn show the smallest variability (CV = < 30%), and Cu the greatest (CV = 12%). Significant correlations (p < 0·001) were found between the following pairs of elements: Cd-Zn, Cd-Cu, Zn-Cu, Mg-Mn, Fe-Mn, Ca-Mg and Fe-210Po.  相似文献   
105.
Marmolino  Ciro  Stebbins  Robin T. 《Solar physics》1989,124(1):23-36
We report detailed comparisons between theoretical and empirical eigenfunctions of velocity and intensity for the 5-min modes in the photosphere. The comparison process is accomplished by obtaining synthetic profiles of the Fei 5434 Å line in the presence of waveforms given by dynamical calculations and then applying a common procedure of reduction both to the observed and to the synthetic data. For the velocity waveforms, our results show a general agreement between theory and observations together with some systematic differences; in particular the theory systematically underestimates the observations in the low photosphere. These systematic differences are stressed by the intensity results since both the computed amplitudes and phases appear to be wrong in the deeper layers.  相似文献   
106.
The fundamentals of stratigraphy have been well understood for more than three centuries and there is now a detailed stratigraphical record reaching back more than one billion years. But this sedimentary rock record is everywhere unpredictably incomplete and yet everywhere similar in its layered character. Computer analyses now reveal the fundamental nature of these two aspects of the record: gaps and layers are governed by simple, seemingly universal, laws that operate regardless of age and sediment type.  相似文献   
107.
The Large Marine Ecosystem (LME) concept is widely established as a large-scale approach to coastal and marine management. LME-oriented activities have focused mainly on natural sciences. Socioeconomic and governance aspects have only recently been receiving increased attention. The 64 LMEs that have been defined appeared to exhibit considerable diversity in characteristics that would be expected to affect governability. This paper explores two questions: (1) Do the LMEs vary widely enough in geopolitical complexity that different approaches to governance may be required for different LMEs? (2) Are there groups of LMEs within which one might take similar approaches to governance? The analysis demonstrates that there is considerable heterogeneity among LMEs with regard to characteristics that would be expected to affect governability. It concludes that a diversity of governance approaches will be required to cope with this heterogeneity. It also appears that LMEs can be grouped according to these characteristics. This suggests that different approaches could be considered for clusters rather than for individual LMEs and that there can be sharing of experience and learning within clusters. The types of relationships between features of LMEs and the ‘best’ approaches to marine governance are discussed in the context of emerging governance ideas.  相似文献   
108.
Robin W. Dennell 《《幕》》2008,31(2):207-210
The main current benefit of collaboration between Quaternary scientists and palaeoanthropologists (especially palaeolithic archaeologists) lies in providing a unique perspective on how human populations respond to longterm climate change. Eurasia has a superlative record of climatic changes over the last two million years, and an archaeological record that is regionally variable in quality, but which is drawn from a wide range of environmental and chronological contexts.  相似文献   
109.
The combined observations of Saturn's moon Enceladus by the Cassini CAPS, INMS and UVIS instruments detected water vapor geysers in which were present molecular nitrogen (N2), carbon dioxide (CO2), methane (CH4), propane (C3H8), acetylene (C2H2), and several other species, together with all of the decomposition products of water. We propose that the presence of N2 in the plume indicates thermal decomposition of ammonia, and hence high temperatures in the interior of the moon (e.g., 500 to 800 K). Such an environment also appears to be suitable for the production of methane (CH4) from carbon monoxide (CO), or carbon dioxide (CO2). The presence of C2H2 and C3H8 strongly suggest that catalytic reactions took place within a very hot environment. The internal environment of Enceladus is inferred to be or have been favorable for aqueous, catalytic chemistry. This permits the synthesis of many complex organic compounds that could be detected in future Cassini observations.  相似文献   
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