Extrapolation of fuzzy values from incomplete data bases

This paper presents different approaches which enable a data base management system to obtain a plausible fuzzy estimate for an attribute value of an item for which the information is not explicitly stored in the data base. This can be made either by a kind of analogical reasoning from information about particular items or by means of expert rules which specify the (fuzzy) sets of possible values of the attribute under consideration, for various classes of items. Another kind of expert rules enables the system to compute an estimate from the attribute value of another item provided that, in other respects, this latter item sufficiently resembles the item, the value of which we are interested in; then these expert rules are used either for controlling the analogical reasoning process or for enlarging the scope of application of the first kind of expert rules. The different approaches are discussed in the framework of possibility theory.     

妊娠相关血浆蛋白A的分离及纯化

采用人胎盘血为原料,利用Sephadex G-200,DEAE-Sephadex A-50层析,Sepharose 4B反相免疫亲和层析技术,获得妊娠相关血浆蛋白A(PAPP-A)纯品,经8.0％聚丙烯酰胺凝胶电泳、免疫电泳、双向免疫扩散证明,所提取的PAPP-A纯品为单一成分。免疫家兔获得抗血清,其效价在1:16以上。     

The influence of experimental conditions on the wear of the metal surface during fretting of steel on polycarbonate

The effects of experimental conditions on the amount of wear of the metal surface during fretting of steel on polycarbonate in laboratory air have been studied within the following limits: amplitude 2–20 μm, frequency 10–120 Hz and normal load 130–830 g. The influence of water vapour on the wear has also been investigated.The polycarbonate induces fretting damage of the steel, with α-Fe₂O₃ particles being transferred from the steel to the polymer surface. After an incubation period during which wear does not take place a running in period occurs during which the rate of wear decreases with the number of cycles, followed by a steady state period, during which the rate of wear remains fairly constant. The length of the incubation period generally increases with decreasing amplitude of slip and with increasing frequency of vibration, while the amount of subsequent wear generally increases with increasing amplitude of slip, with decreasing frequency of vibration and with decreasing applied load within the range studied. It is found that water vapour content has the most significant effect on the amount of wear. In moist oxygen, moist argon and moist nitrogen (relative humidity about 85%) the amount of wear is greater than in laboratory air (relative humidity about 50%), while in dry gases virtually no wear of the metal is observed.     

Systematic study of back pressure and anode stoichiometry effects on spatial PEMFC performance distribution

A segmented cell system was applied to investigate the effects of the anode and cathode back pressure and hydrogen stoichiometry on fuel cell performance in terms of overpotential distributions along the flow field. The segmented cell system was designed with closed loop Hall sensors and a data acquisition system allowing simultaneous spatial electrochemical impedance spectra (EIS) measurements. It was determined that an increase in back pressure for the tested serpentine flow field design results in an improvement of the cell performance and uneven improvement of individual segments’ performance. In general, the performance and the overpotentials become more uniform downstream with an increase in the back pressure due to a decrease in activation and mass transfer losses. Spatial EIS data for the PEMFC operated at different back pressures support the overpotential analysis. Hydrogen stoichiometry variations do not affect the performance of the cell or the individual segments at low current density because there is no significant hydrogen concentration gradient in the flow field. However, at high current densities a reduction in hydrogen stoichiometry produces a slight decrease in performance for inlet segments while outlet segments showed a noticeable performance loss. The decrease in performance is attributed to an increase in mass transfer losses due to nitrogen diffusion from the cathode to the anode. This effect becomes more pronounced for the outlet segments due to a downstream nitrogen accumulation. Under high current density conditions, the cell is locally fuel starved even with a high fuel stoichiometry creating conditions leading to cell degradation by carbon corrosion. More importantly, this local degradation is masked by the overall cell performance which remains largely unaffected.     

Break Expectancy in Duration Discrimination.

Effects of break expectancy, observed previously in time production, were examined in 3 experiments using a discrimination paradigm. Participants classified a tone as being short or long. Location and duration of breaks in tone presentation were varied. Proportion of short responses increased as the break occurred later in the duration to be estimated in all experiments. With a higher number of break locations covering a wider range of location values, functions relating proportion of short responses to location were sigmoid and tended to flatten at extreme values of location. The authors conclude that attentional time-sharing elicited by break expectancy induces loss in accumulation of temporal information, but its effect on discrimination depends on the accumulation outcome relative to a decisional criterion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in stimulus intensity modulation and its relationship to two styles of depression in older adults.

Research comparing depressive persons with and without manic symptoms shows striking parallels with differences between augmenters and reducers on the Kinesthetic Aftereffect (KAE) task (A. Petrie, 1967). Twenty-three community-dwelling older adults identified by the Minnesota Multiphasic Personality Inventory (S. R. Hathaway & J. C. McKinley, 1951) as depressive without manic symptoms were compared with 24 older adults with manic symptoms on the KAE, the NEO Personality Inventory (NEO-PI; P. T. Costa & R. R. McCrae, 1985), and Strelau (J. Strelau, 1983) Temperament Inventory. As hypothesized, augmentation was related to depression without manic symptoms, and reduction was related to depression with manic symptoms. Stepwise discriminant analyses indicated that the KAE is a potent discriminator between the 2 types of depression. Three characteristics of Strelau's "strength of nervous system"—excitation, and inhibition and mobility—discriminate significantly between the 2 groups as well as NEO extraversion and conscientiousness. Results suggest that older depressive persons with and without manic symptoms may benefit from different therapeutic interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phenolic compounds and plant extracts protect paprika against UV-induced discoloration

The efficiency of phenolic antioxidants in protecting paprika carotenoids against discoloration was studied in a model gel system that was exposed to radiation of 274 nm at 20 °C. The fading of the colour of the gel was followed over a 6‐h period. Fifty percent of the colour faded from the control after 70 min of radiation. The ability of each antioxidant to prevent discoloration was assessed by using several different concentrations. Antioxidant compounds can be ranked according to their protective effect on colour: BHT > α‐tocopherol > epigallocatechin gallate > quercetin > rosmarinic acid ≥ caffeic acid and ferulic acid > coumaric acid > catechin. The ability of rosemary and tea extracts to prevent discoloration was comparable to pure compounds and this could be explained by their polyphenol content. Mixtures of α‐tocopherol with rosemary extract revealed strong synergistic effects.