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131.
132.
The main tasks for climate controllers in potato bulk stores are to keep the storage climate in an appropriate condition for quality conservation. To avoid extra energy costs by using cooling systems the internal climate of potato bulk stores is controlled with outdoor air. A conventionally designed controller is difficult to adapt for an optimal climate control to reduce quality loss. However, a controller designed with fuzzy logic is found as advantageous for adapting control parameters to improve the control process. A test stand is built to ventilate and to control two samples of potato bulks simultaneously with the same outdoor weather conditions for comparisons. Several experiments were carried out to compare climate controllers with different control algorithms, i.e. conventional to a different conventional and conventional to fuzzy.  相似文献   
133.
Clan and land     
Fischer JL 《Science (New York, N.Y.)》1977,195(4284):1321-1322
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134.
By focusing a highly brilliant synchrotron x-ray beam to a micrometer spot on a sample, we measured in real time the x-ray intensity fluctuations associated with order fluctuations in crystalline materials. We applied this method to the binary alloy Fe3Al near its continuous A2-B2 phase transformation and determined a specific four-point time correlation function for the order parameter. From a detailed theoretical analysis, dynamical scaling in the time domain with a transition from noncritical to critical dynamics is disclosed.  相似文献   
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136.
Theory predicts the existence of barrierless protein folding. Without barriers, folding should be noncooperative and the degree of native structure should be coupled to overall protein stability. We investigated the thermal unfolding of the peripheral subunit binding domain from Escherichia coli's 2-oxoglutarate dehydrogenase multienzyme complex (termed BBL) with a combination of spectroscopic techniques and calorimetry. Each technique probed a different feature of protein structure. BBL has a defined three-dimensional structure at low temperatures. However, each technique showed a distinct unfolding transition. Global analysis with a statistical mechanical model identified BBL as a downhill-folding protein. Because of BBL's biological function, we propose that downhill folders may be molecular rheostats, in which effects could be modulated by altering the distribution of an ensemble of structures.  相似文献   
137.
We present the genomic sequence of Legionella pneumophila, the bacterial agent of Legionnaires' disease, a potentially fatal pneumonia acquired from aerosolized contaminated fresh water. The genome includes a 45-kilobase pair element that can exist in chromosomal and episomal forms, selective expansions of important gene families, genes for unexpected metabolic pathways, and previously unknown candidate virulence determinants. We highlight the genes that may account for Legionella's ability to survive in protozoa, mammalian macrophages, and inhospitable environmental niches and that may define new therapeutic targets.  相似文献   
138.
Stable carbon cycle-climate relationship during the Late Pleistocene   总被引:2,自引:0,他引:2  
A record of atmospheric carbon dioxide (CO2) concentrations measured on the EPICA (European Project for Ice Coring in Antarctica) Dome Concordia ice core extends the Vostok CO2 record back to 650,000 years before the present (yr B.P.). Before 430,000 yr B.P., partial pressure of atmospheric CO2 lies within the range of 260 and 180 parts per million by volume. This range is almost 30% smaller than that of the last four glacial cycles; however, the apparent sensitivity between deuterium and CO2 remains stable throughout the six glacial cycles, suggesting that the relationship between CO2 and Antarctic climate remained rather constant over this interval.  相似文献   
139.
We introduce a spectroscopic method that determines nonlinear quantum mechanical response functions beyond the optical diffraction limit and allows direct imaging of nanoscale coherence. In established coherent two-dimensional (2D) spectroscopy, four-wave-mixing responses are measured using three ingoing waves and one outgoing wave; thus, the method is diffraction-limited in spatial resolution. In coherent 2D nanoscopy, we use four ingoing waves and detect the final state via photoemission electron microscopy, which has 50-nanometer spatial resolution. We recorded local nanospectra from a corrugated silver surface and observed subwavelength 2D line shape variations. Plasmonic phase coherence of localized excitations persisted for about 100 femtoseconds and exhibited coherent beats. The observations are best explained by a model in which coupled oscillators lead to Fano-like resonances in the hybridized dark- and bright-mode response.  相似文献   
140.
With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.  相似文献   
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