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Control of spatiotemporal chaos is one of the central problems of nonlinear dynamics. We report on suppression of chemical turbulence by global delayed feedback using, as an example, catalytic carbon monoxide oxidation on a platinum (110) single-crystal surface and carbon monoxide partial pressure as the controlled feedback variable. When feedback intensity was increased, spiral-wave turbulence was transformed into new intermittent chaotic regimes with cascades of reproducing and annihilating local structures on the background of uniform oscillations. The global feedback further led to the development of cluster patterns and standing waves and to the stabilization of uniform oscillations. These findings are reproduced by theoretical simulations.  相似文献   
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The microscopic mechanism of the matching effect in a superconductor, which manifested itself as the production of peaks or cusps in the critical current at specific values of the applied magnetic field, was investigated with Lorentz microscopy to allow direct observation of the behavior of vortices in a niobium thin film having a regular array of artificial defects. Vortices were observed to form regular and consequently rigid lattices at the matching magnetic field, at its multiples, and at its fractions. The dynamic observation furthermore revealed that vortices were most difficult to move at the matching field, whereas excess vortices moved easily.  相似文献   
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Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.  相似文献   
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The main results of the International Co-operative Programme on Effects on Materials, including Historic and Cultural Monuments (ICP Materials) within the United Nations Economic Commission for Europe (UN ECE) are summarised. The 8-year field exposure programme involves 39 test sites in 12 European countries and in the United States and Canada. Dose-response functions (DRF) expressing the effect of dry and wet deposition as individual terms have been obtained for a wide range of materials including bronze, copper, weathering steel, zinc, aluminium, nickel, tin, stone materials, paint coatings and glass materials. The DRF's includes parameters that are easily available on different geographical scales and can be used for mapping areas of increased corrosion rates and for calculation of costs.  相似文献   
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Computational experiments with the ROMUL mathematical model were performed for studying the dynamics of soil organic matter (SOM) in spruce forests of northeastern Czechia that were disturbed because of the atmospheric sulfur deposition in the second half of the 20th century. The effect of the soil acidification on the decomposition dynamics of the forest die-back in the model is of importance. Conditions of the forest productivity were found under which the SOM pool could be preserved. It was shown that, later on, the content of the litter will decrease because of the forest degradation, and the succession changes due to the effect of the contamination will affect the type of vegetation, as well as the type of soil organic matter. The total SOM content will decrease in this case. However, the maintenance of the grass productivity can slow down this process. It was noted that the quantitative prediction of the SOM dynamics requires measurements of the productivity parameters of the forest as a whole and the living ground cover, including the content of root litter, and the hydrothermal regime of the soil determining the transformation of the litter and humus.  相似文献   
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The Atlantic cod (Gadus morhua) and red king crab (Paralithodes camtschaticus) processing wastes are massive and unutilized in the Murmansk region of Russia. The samples of skin-containing waste of Atlantic cod fillets production were hydrolyzed using enzyme preparations derived from red king crab hepatopancreases, porcine pancreases, and Bacillus subtilis bacteria. The activity of enzymes from crab hepatopancreases was significantly higher than the activity of enzymes derived from other sources. The optimal conditions of the hydrolysis process have been figured out. The samples of cod processing waste hydrolysate were analyzed for amino acid composition and molecular weight distribution. The samples of hydrolysate were used as core components for bacterial culture medium samples. The efficiency of the medium samples was tested for Escherichia coli growth rate; the most efficient sample had an efficiency of 95.3% of that of a commercially available medium based on fish meal. Substitution of medium components with those derived from industrial by-products is one of the ways to decrease a cost of a culture medium in biopharmaceutical drug production.  相似文献   
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Eurasian Soil Science - Investigations of changes in the soil and plant covers is necessary when designing technical objects—gas and oil pipelines, highways, and power lines—in order to...  相似文献   
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Issues pertaining to the environmental potential in decreasing the damage due to atmospheric corrosion and the evaluation of atmospheric corrosivity for materials on the territory of the former USSR and Russia are considered. The most significant results obtained under the UN ECE Programme on Effects on Materials, including Historic and Cultural Monuments are discussed. The evaluation procedures and the first results of the mapping of the European part of Russia according to the relative air humidity and yearly values of time of wetness are reported. It is concluded that the multiplicative approach to the creation of damage functions for materials and the developed conception of acceptable levels are good basis for mapping of the European part of Russia. The problems of mapping of the Asian part of Russia are not solved for extremely cold regions with low values of the time of wetness.  相似文献   
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