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1.
The paper reports an investigation on a continuous model for dynamics of large-diameter sagged cables, taking bending stiffness and sag extensibility into account. Following the classical guidelines of cable dynamics, and by making some simplifications, a continuous model is found in this work; frequency and mode shape equations have been obtained in non-dimensional form. Comparison with Finite Element (FE) and Finite Difference (FD) models has been made to validate the proposed method. Moreover, it allows us to represent local effects at the end zones of cable correctly, if clamped boundary conditions are assumed. To obtain comparable results, the FE model would require a large subdivision, with consequently, a large number of elements. The proposed eigenfunctions allow us to solve the dynamic problem without a large computational effort compared to FE or FD approaches. Finally, in order to show the usefulness of the developed continuous model, an application on the main cables of the designed Messina Strait Bridge has been made.  相似文献   
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We evaluated Henley's (1973, 1977) and Goffman's (1976, 1979) theories about the relation between gender, nonverbal behavior, and perceived dominance in three studies. Our ratings of 1,106 media portrayals (Study 1) and observations of 1,257 people in public settings (Study 2) revealed few gender differences in frequency of head canting or body canting but some gender differences in frequency of smiling. In Study 3, we rated 96 advertisements that included all levels of gender, head cant, body cant, and smiling on five personality dimensions; we obtained only one predicted relation with dominance. It may be that the head canting, body canting, and smiling behaviors of females and males are actually more similar than was previously recognized and, contrary to hypotheses, dominance may not be strongly associated with these behaviors. We used previously suggested notions of gender as a categorizing strategy and as a diffuse status characteristic to explain why hypotheses that associate nonverbal behaviors with dominance and gender have had an acceptance unwarranted by the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Two MAIPA (monoclonal antibody [MAb] immobilization of platelet antigen) assays were performed to determine (a) autoantibodies to platelet glycoproteins (GP) and (b) serum antibodies recognizing mouse MAbs used in the assay. In MAIPA I, control platelets were incubated simultaneously with human serum and a mouse MAb to a platelet glycoprotein (GP IIb-IIIa, Ib-IX, Ia-IIa, IV and p24). In MAIPA II, the control platelets were incubated first with the human serum and then, after washing, with the selected mouse MAb. A series of 25 patients with autoimmune thrombocytopenic purpura (ATP) associated or not with other autoimmune states were examined. Autoantibodies (both MAIPA I and MAIPA II positive) or anti-mouse Abs (MAIPA I positive and MAIPA II negative) were frequent in both groups of patients. Statistically significant differences existed in the incidence of anti-mouse Abs between patients (56.5%) and healthy donors (10%). This suggests that their production may be related to thrombocytopenias associated with autoimmune disease. We speculate that the presence of anti-mouse antibodies could reflect an abnormality in the immunological modulation of the idiotypic network.  相似文献   
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Saitta  Lorenza  Botta  Marco  Neri  Filippo 《Machine Learning》1993,11(2-3):153-172
This article presents the system WHY, which learns and updates a diagnostic knowledge base using domain knowledge and a set of examples. The a priori knowledge consists of a causal model of the domain that states the relationships among basic phenomena, and a body of phenomenological theory that describes the links between abstract concepts and their possible manifestations in the world. The phenomenological knowledge is used deductively, the causal model is used abductively, and the examples are used inductively. The problems of imperfection and intractability of the theory are handled by allowing the system to make assumptions during its reasoning. In this way, robust knowledge can be learned with limited complexity and a small number of examples. The system works in a first-order logic environment and has been applied in a real domain.  相似文献   
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Vanadium pentoxide (V2O5) nanocrystals having few tens nanometers average size, are obtained from ammonium metavanadate (NH4VO3) in the presence of oleic acid, and treating the reaction product at 400 °C. Nanocrystalline films, deposited from stable ethanol suspensions of the V2O5 nanopowder, adhere strongly to different kinds of substrates, without the need of any thermal post processing. At room temperature, the films are found to bleach when exposed to ammonia. Bleaching originates from the formation of ammonium metavandate, and is reversible, as after annealing in air at 350 °C, ammonium metavanadate converts back to V2O5. Formation of ammonium metavanadate, clearly evidenced by remarkable changes in infrared spectrum of V2O5 films exposed to ammonia, is a valuable detection mechanism, promising in view of developing highly selective ammonia sensors operating at room temperature.  相似文献   
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G. Rizzo  N. Donato  G. Saitta  G. Neri 《Thin solid films》2010,518(23):7133-1403
A stable chlorobenzene dispersion of conducting polyaniline (PANI) has been obtained by doping emeraldine base with dodecylbenzene sulfonic acid (DBSA) and studied by spectrophotometric measurements in the UV-vis-IR range. The electrical properties of PANI: DBSA films obtained from the above dispersion have been investigated under different temperature and relative humidity conditions. All-organic chemoresistive devices have been developed by spin-coating the PANI: DBSA dispersion on flexible substrates, and then by depositing electrodes on the top, from a carbon nanotube conducting ink. Sensing tests performed under exposition to calibrated amounts of ammonia reveal that these simple and inexpensive sensors are able to detect ammonia at room temperature in a reliable way, with a sensitivity linearly related to concentration in the range between 5 ppm and 70 ppm.  相似文献   
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Food Science and Biotechnology - The National Institute of Crop Science, Rural Development Administration (RDA) of Korea is presently developing new rice varieties suitable for producing Western...  相似文献   
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Enantiomeric separations were performed on five modified polysaccharide-based chiral stationary phases (CSPs) containing cellulose tris(3,5-dimethylphenylcarbamate) (Lux Cellulose-1), cellulose tris(3-chloro-4-methylphenylcarbamate) (Lux Cellulose-2), cellulose tris(4-methylbenzoate) (Lux Cellulose-3), cellulose tris(4-chloro-3-methylphenylcarbamate) (Lux Cellulose-4), amylose tris(5-chloro-2-methylphenylcarbamate) (Lux Amylose-2) by high-performance liquid chromatography and evaporative light scattering detector. A method for direct separation of pairs of sn-1(3)-monoacylglycerols (MAGs) was established using n-hexane/2-propanol as the mobile phase. The washing of CSPs with mobile phases based on n-hexane/2-propanol, containing small amount of acids, improved considerably the efficiency of separations. Racemic mixtures of sn-1(3)-MAGs with different acyl chains could not be directly separated using only one of the columns tested; employing a tandem column system that consisted of a very short silver-loaded column connected downstream with Lux Cellulose-1 the method allowed, for the first time, the separation of four enantiomeric pairs of standard in a single chromatographic run.  相似文献   
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