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151.
Transferability of the properties of fatigue in the local approach This article deals with the uncertainty of lifetime prediction. There are to reasons for still unsatisfying calculation results, known as transferability problems. The first appears when using strength under constant amplitude loading for the prediction of operational loaded structures. The second transferability problem exists only in the local strain approach where the strength of the unnotched small specimen is assumed to be valid for the real component as well. This difficulty is dealt with by separating the independent influences and its individual consideration. The microstructural mechanics influence is derived by a statistical evaluation of experimental data. The proposed concept for regarding the microstructural support effect allows o derive a strain‐life‐curve for an individual component. The results of verification look promising. 相似文献
152.
153.
John‐Jules Ch. Meyer 《国际智能系统杂志》2006,21(6):601-619
In this article we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular, we formalize in this framework how emotions are related to the action monitoring capabilities of an agent. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 601–619, 2006. 相似文献
154.
Seasonal affective disorder (SAD) is characterized by annual major depressive episodes. It occurs most commonly in young women during autumn and winter with full remission during the following spring. The patient's mood is a combination of depression and anxiety accompanied by fatigue, loss of libido, and a reduction of socialization. Most of these patients complain of atypical vegetative symptoms (e.g. hypersomnia, carbohydrate craving, and weight gain). Hypotheses on the underlying mechanisms of these behavioural disorders indicate that environmental variables, e.g. climate, latitude, light, and changes in neurotransmitter function that occur naturally with the seasons, may be important. Phototherapy is being used increasingly for the treatment of SAD. The antidepressant response is contingent on the exposure of the patients' eyes to light. The biological basis of the diverse psychological and biological changes in SAD and the underlying mechanism of action of phototherapy are still unclear and require further study. 相似文献
155.
Rypniewski W.R.; Hastrup S.; Betzel Ch.; Dauter M.; Dauter Z.; Papendorf G.; Branner S.; Wilson K.S. 《Protein engineering, design & selection : PEDS》1993,6(4):341-348
The trypsin from Fusarium oxysporum is equally homologous totrypsins from Streptomyces griseus, Streptomyces erythraeusand to bovine trypsin. A DFP (diisopropylfluorophosphate) inhibitedform of the enzyme has been crystallized from 1.4 M Na2SO4,buffered with citrate at pH 5.05.5. The crystals belongto space group P21 with cell parameters a=33.43 Å, b=67.65Å, c=39.85 Å and ß=107.6°. There isone protein molecule in the asymmetric unit. X-ray diffractiondata to a resolution of 1.8 Å were collected on film usingsynchrotron radiation. The structure was solved by molecularreplacement using models of bovine and S.griseus trypsins andrefined to an R-factor of 0.141. The overall fold is similarto other trypsins, with some insertions and deletions. Thereis no evidence of the divalent cation binding sites seen inother trypsins. The covalently bound inhibitor molecule is clearlyvisible. 相似文献
156.
At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titration have shown that the polycaprolactone obtained is of two carboxyl end groups. The molecular weight of it increases with decreasing of the acid content in the reaction mixture under the same polymerization conditions. With a certain ratio of acid to caprolactone. the maximum of molecular weight of the polymer will be reached at the reaction time of 3h. 相似文献
157.
158.
This work begins with a summary of the characteristics of electromagnetic casting and the present knowledge of the subject.
Also described is the use of new local measurement techniques for velocity, magnetic field, current density, and phase difference,
which allow experimental investigation of the flow of molten metal in industrial equipment (up to 700 °C) in the presence
or absence of an induction magnetic field. Next, these methods are applied to the study of electromagnetic and hydrodynamic
phenomena, inside the sumps of both rectangular and circular cross-section ingots of aluminum alloys cast in electromagnetic
molds. The important shield effect as a function of the screen location is studied by means of a mercury pool simulating electromagnetic
casting. 相似文献
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160.
Electrochemical perfluorination of octane-sulphofluoride (OSF) and octanoic-fluoride (OF) to the perfluoro compounds (POSF and POF) has been studied over a wide range of experimental conditions. Significant improvement of the reported yield of perfluoro-product has been achieved with electrolysis at high potential. The results are explained in terms of a model involving simultaneous adsorption of the reactant and of fluorine on a NiF2 surface. 相似文献