This is an experimental economics research on human behaviour in “small decision making”. I set up ambiguity treatments in which there are two states of nature: a favourable state and an unfavourable state, but only one of them obtains on any given trial. The decision makers’ basic task is a binary choice between a risky option with higher expected value and a riskless option with lower expected value. The one-person game is iterated hundreds of times. Experimental results are reported with several findings, such as underweighting of rare events and deviations from expected value maximisation. Finally, I investigate the imperfect Bayesian decision makers observed in the experiments by exploring to what extent they can update prior probabilities and reflect it in making decisions.
A 32-year-old male was diagnosed as having miliary tuberculosis in May 1990. In spite of antituberculosis chemotherapy, he developed tuberculous meningitis and intracranial tuberculoma in September 1990. Miliary shadows on chest X-ray disappeared in December 1990. However, he developed left atelectasis, and bronchofiberscopy revealed soft tumor in the left main bronchus in January 1991. He suddenly vomited large amounts of blood and expired in February 1991. At autopsy, tuberculous lymphadenitis and cavitation were noted in the mediastinum, through which the left main bronchus, esophagus and descending aorta communicated. The patient died of massive bleeding which resulted from the rupture of tuberculous aortitis into the esophagus. This is a very rare case of tuberculous aortic aneurysm rupturing into both the bronchus and esophagus. 相似文献
Extremely large grain size AIN ceramics were produced by HIP sintering at an ultra-high temperature of 2773 K without reducing the oxygen content in order to determine experimentally whether the factor controlling thermal conductivity is either grain boundaries or the internal structure of the grains. The room-temperature thermal conductivity of the HIPed AIN with a grain size of 40 m was 155 Wm–1 K–1, and was almost equal to that of the normally sintered AIN with a grain size of 4 m. Therefore, thermal conductivity at room temperature is independent of AIN grain size, or the number and amount of grain-boundary phase for reasonably well-sintered AIN ceramics. The calculated phonon mean free path of sintered bodies was 10–30 nm at room temperature, which is too small to compare with the AIN grain size. Consequently, it is shown that the thermal conductivity of sintered AIN is controlled by the internal structure of the grains, such as oxygen solute atoms. 相似文献
Summary The chemical process of preparing poly(vinylchloride)-polypyrrole composite films with high electrical conductivity and transparency has been studied. Pyrrole has been diffused into the poly(vinylchloride) matrix in the swelling medium of n-hexane and acetone mixture. The oxidative polymerization of the diffused pyrrole in the binary solvent system of acetonitrile and methanol gives high conductivity of the polypyrrole as well as the good penetration of the oxidant into the PVC polymer matrix. The analytical testing of the composite film shows the formation of homogeneous mixture of polypyrrole and poly(vinylchloride) conductive layer within the 1.0m of thickness on the film surface. The transparency of the composite film showed about 50–60% at 500 nm. The electrical conductivity of the composite was about 20 s/cm. 相似文献
Partially biobased polyamphiphile-bearing reactive epoxy groups in the side chains were obtained in 62–78 % yields by a radical copolymerization of limonene oxide (LO) and PEG methylacrylate (PEGA) with different feed ratios. Degree of LO incorporation into the copolymer was determined as 12–23 % by 1H NMR spectroscopic analysis. The copolymer having LO unit:PEGA unit = 19:81 formed polymer associates in water, particle diameter of which was ranged mainly from 4 to 66 nm and hydrodynamic mean diameter was 12.3 nm. Its critical micelle concentration was determined as 0.53 g/L by fluorescence spectroscopic analysis. A cross-linking reaction of the epoxy groups in the side chains was conducted with 3.97 mol% (to the epoxy group) of branched poly(ethylene imine) as a cross-linker to give the corresponding hydrogel in 56 % yield. The hydrogel can absorb water as much as 13 times its own mass. 相似文献
The present study was undertaken to report a new method which reveals the ultrastructure of freeze-fractured membrane faces. The method consists of initial replication of fractured surfaces of frozen specimens with evaporated carbon and treatment of the replicas with a negative staining solution after dissolution of specimens. This negative staining-carbon replica method reveals clear distribution, ultrastructures and precise size of intramembrane particles on the fractured membrane faces by means of density difference of negative staining solution which is deposited on the surfaces of carbon replicas. 相似文献
Polystyrene-b-poly(methyl acrylate) (PS-b-PMA) block copolymer with PS volume fraction of 25.2 vol% was synthesized by atom transfer radical polymerization. Non-pretreated silicon wafers were used as the substrates to prepare perpendicular oriented PS cylinders in PMA matrix via solvent annealing which could induce the transformation of spheres to vertically oriented and hexagonally packed cylinders. The spherical microdomains were formed after the evaporation of solvents from the solutions of the block copolymer in selective solvents mixed from methanol, acetone and dichloromethane. The thickness of films could be as thick as 1000 nm, which were much thicker than usual cases and the cylinders came from the directional coalescence of the spheres, thus any pre-treatments of the substrates were not required for perpendicular orientation. The structures were characterized by small angle X-ray scattering (SAXS), transmission electron microscope (TEM), atom force microscopy (AFM) and grazing incidence small angle X-ray scattering (GISAXS). 相似文献
Several Fe-Cr-Ni austenitic stainless steels (Cr wt.%: 13–25, Ni wt.%: 15) were oxidized in steam for 1000 hr at 500–900°C. The oxide scales were examined and categorized with respect to the chromium concentration and the grain size of the base metal. Experiments showed three conditions for the critical bulk Cr concentration and the oxidation temperature at which the oxidation behavior changed drastically. Metallographic examination showed that two of these three conditions resulted from the internal-external transition of Cr2O3 either on the metal surface or along the grain boundaries of the base metal. Attempts were made to interpret these conditions from the available oxidation theories. Atkinson's treatment was employed with some modification to incorporate the grain-boundary diffusion of Cr in the base metal. The calculation basically explained the internal-external transition for the oxidation of these steels. 相似文献