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During the last two decades, the first generation of beam combiners at the Very Large Telescope Interferometer has proved the importance of optical interferometry for high-angular resolution astrophysical studies in the near- and mid-infrared. With the advent of 4-beam combiners at the VLTI, the u ? v coverage per pointing increases significantly, providing an opportunity to use reconstructed images as powerful scientific tools. Therefore, interferometric imaging is already a key feature of the new generation of VLTI instruments, as well as for other interferometric facilities like CHARA and JWST. It is thus imperative to account for the current image reconstruction capabilities and their expected evolutions in the coming years. Here, we present a general overview of the current situation of optical interferometric image reconstruction with a focus on new wavelength-dependent information, highlighting its main advantages and limitations. As an Appendix we include several cookbooks describing the usage and installation of several state-of-the art image reconstruction packages. To illustrate the current capabilities of the software available to the community, we recovered chromatic images, from simulated MATISSE data, using the MCMC software SQUEEZE. With these images, we aim at showing the importance of selecting good regularization functions and their impact on the reconstruction.  相似文献   
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A large planar rock slide in the Hamersley Range, Western Australia, is described and analysed for possible causes of failure. The general characteristics of the slide are determined by the major joint sets. The rock mass consists predominantly of alternating massive chert members and argillaceous horizons—giving the rock mass a distinctive flaggy appearance. The failure plane dips at 17° and is coincident with a shale horizon. Because of the low inclination of the failure plane factors of safety less than one cannot be obtained from limiting-equilibrium hindcast estimates, unless high joint-water pressures and/or seismic loading are invoked. But while the operation of these two factors cannot be totally ruled out, the field evidence suggests that the necessary conditions for failure were due to the weathering out of shale horizons which could have led to “adjustments” of the rock mass, giving rise to dynamic loading conditions along potential failure planes.  相似文献   
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A crop-growth-simulation model based on SUCROS87 was used to study effects of temperature rise and increase of atmospheric CO2 concentration on wheat yields in several regions in Europe. The model simulated potential and water-limited crop production (growth with ample supply of nutrients and in the absence of damage by pests, diseases and weeds). Historic daily weather data from 13 sites in Western Europe were used as starting point.For potential production (optimal water) a 3 °C temperature rise led to a yield decline due to a shortening of the growing period on all locations. Doubling of the CO2 concentration caused an increase in yield of 40% due to higher assimilation rates. It was found that effects of higher temperature and higher CO2 concentration were nearly additive and the combination of both led to a yield increase of 1–2 ton ha-1. A very small CO2-temperature interaction was found: the effect of doubled CO2 concentration on crop yield was larger at higher temperatures. The inter-annual yield variability was hardly affected.When water was limiting crop-production effects of temperature rise and higher CO2 levels were different than for the potential production. Rise in temperature led to a smaller yield reduction, doubled CO2 concentration to a larger yield increase and combination of both led to a large yield increase (3 ton ha-1) in comparison with yields simulated for the present situation. Both rise in temperature and increase in the CO2 concentration reduced water requirements of the crop. Water shortages became smaller, leading to a reduction in inter-annual variability. It is concluded that when no major changes in precipitation pattern occur a climate change will not affect wheat yields since negative effects of higher temperatures are compensated by positive effects of CO2 enrichment.  相似文献   
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The Holocene history of the northwest Australian monsoon is considered in the light of new stratigraphic findings from the southern margin of the monsoon regime. A discussion of the present-day climatology of northwestern Australia and synoptic controls on precipitation in the areas at the southern margin of the monsoon regime is given as background information for the interpretation of stratigraphic findings from swamp and alluvial sequences. The stratigraphic findings point to little change in the intensity of the northwest Australian monsoon since ca. 6.5 ka. A more tentative inference drawn from the field evidence is that the monsoon activity may well have been reduced in this region during the Early Holocene; during this time insolation levels were also reduced. The possible relationship of the northwest Australian monsoon to insolation levels is explored. It is clear that monsoon behavior cannot be accounted for as a simple linear response of monsoon intensity to variations in insolation. Possible controls are discussed with particular emphasis on the plausibility of changes in the damping of convective motions providing the mechanism. Gill's model of heat-induced circulation is used to provide some evidence in favour of this conjecture.  相似文献   
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