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111.
Mikhail Yu. Sinev Yurii P. Tulenin Olga V. Kalashnikova Viktor Yu. Bychkov Vladimir N. Korchak 《Catalysis Today》1996,32(1-4):157-162
The analysis of methane oxidation in a wide range of pressures (0.05–10 atm) demonstrates that the efficiency of CH3 radicals recombination is of great importance for high selectivity of C2 hydrocarbons formation. The relative efficiency of different “colliders” assisting the stabilization of exited C2H*6 molecules increases in the series: solid surface> Ar> He. The increase of the overall reaction rate upon increasing pressure of the inert gases in the case of catalysts having a higher surface area and more developed pore structure is likely due to the contribution of the surface-induced chain reaction in the volume of pores. 相似文献
112.
Konrad Grob Angelo Maria Giuffr Ugo Leuzzi Biagio Mincione 《European Journal of Lipid Science and Technology》1994,96(8):286-290
Recognition of adulteration by other oils via direct analysis of the minor components (“sterol fraction”) is shown for olive oil. 10 % of various oils were admixed, the free alcohols silylated and the minor components analyzed by on-line coupled LC-GC-FID. For most oils, even smaller additions can be recognized. Admixed oils can no longer be determined, however, if their minor components have been removed by strong raffination. Bleaching of rapeseed oil with 7% of earth at 180 °C, in fact, completely removed free and esterified sterols. 相似文献
113.
The lipid composition of blubber, brain, muscle and heart from a Mediterranean monk sealMonachus monachus (an endangered species) were examined to allow comparisons with more common species of seals. Only neutral lipids (mainly
triacylglycerols) were detectable in the blubber lipids, whereas polar lipids predominated in the heart and in the brain.
Neutral and polar lipids comprised almost equal proportions in both liver and muscle. Choline glycerophospholipids (CGP) were
the major polar lipids, followed by ethanolamine glycerophospholipids (EGP) in the liver, heart and muscle. Cerebrosides accounted
for 28.8% of the brain lipids. All lipid classes of the liver contained high levels (31–47%) of polyunsaturated fatty acids
(PUFA), with the exception of phosphatidylserine. The total proportion of n−6 PUFA exceeded that of n−3 PUFA in all lipid
classes of the liver, due mainly to the high levels of 20∶4n−6. The highest level of 20∶4n−6 occurred in phosphatidylinositol,
where it comprised 32.4% of the total fatty acids. The CGP and EGP of the brain contained lower levels of PUFA than those
of the liver, muscle and heart. Alkenyl ethers accounted for 35.8% of the total long-chain moieties in brain EGP. The fatty
acid composition of blubber triacylglycerols differed from those of the lipid classes from other tissues in that it had a
very low ratio of n−6 to n−3 PUFA (0.3) as a result of a lower content of 20∶4n−6. 相似文献
114.
Automatic visual inspection has become one of the active research issues in machine vision technology in the past decades. Most of the methodologies developed address the problems of defect detection on a nontextured or regularly textured surface. However, problems in detecting defects on a randomly textured surface, especially cracks, have not received much attention. In this paper, we present a novel algorithm that uses a Wigner model to identify cracks in complex textural backgrounds, regardless of whether the inspected surface is randomly or regularly textured. We also investigate the windowing characteristics of the Wigner distribution and their impact on crack detection. Some of the Brodatz' natural texture images have been used for evaluating the performance of the algorithm. Promising results are obtained and presented in this paper. 相似文献
115.
Jarrett Robin B.; Basco Monica R.; Risser Richard; Ramanan Janaki; Marwill Maria; Kraft Dolores; Rush A. John 《Canadian Metallurgical Quarterly》1998,66(6):1036
Two pilot studies evaluated the rate of relapse or recurrence (i.e., major depressive disorder) after cognitive therapy (CT). Two sequential cohorts included outpatients who responded to acute phase CT (A-CT) and who agreed to monthly, treatment-free follow-up. In Study 1, the Kaplan-Meier technique estimated relapse and recurrence rates of 40% at 6 months, 45% at 8 months, 50% at 12 months, 67% at 18 months, and 74% at 24 months. In Study 2, responders to A-CT received 8 months (10 sessions) of continuation phase CT (C-CT). In Study 2, relapse or recurrence was 20% at 6 and 8 months, 27% at 12 months, and 36% at 18 and 24 months after A-CT. An exploratory log-rank test showed that relapse or recurrence-free survival was greater in Study 2 than in Study 1. If replicated, this result suggests that C-CT can reduce depressive relapse or recurrence. Alternative explanations are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
116.
Ioanna Roussaki Maria Strimpakou Carsten Pils 《Journal of Network and Systems Management》2007,15(1):57-74
The challenge of saturating all phases of pervasive service provision with context-aware functionality lies in coping with
the complexity of maintaining, retrieving and distributing context information. To efficiently represent and query context
information a sophisticated modelling scheme should exist. To distribute and synchronise context knowledge in various context
repositories across a multitude of administrative domains, streamlined mechanisms are needed. This paper elaborates on an
innovative context management framework that has been designed to cope with free-text and location based context retrieval
and efficient context consistency control. The proposed framework has been incorporated in a multi-functional pervasive services
platform, while most of the mechanisms it employs have been empirically evaluated. 相似文献
117.
Maria G Corradini Mark D Normand Micha Peleg 《Journal of the science of food and agriculture》2006,86(5):785-792
Currently, the sterility of heat‐processed food and pharmaceuticals is assessed in terms of an F0 value, based on the equivalence of the heat treatment to an isothermal process at a reference temperature. This F0 value, however, has a meaning if, and only if, the inactivation kinetics of the targeted spores (or cells) follow a first‐order relationship and the temperature dependence of the D value, the reciprocal of the rate constant, is log‐linear. There is growing evidence that these conditions are not satisfied by many spores, including those of Clostridium botulinum and vegetative cells. Consequently, a replacement for the F0 value is proposed in the form of a momentary equivalent time at the reference temperature based on the actual survival pattern of the spores, which need not be log‐linear. This equivalent time can be calculated together with the theoretical survival ratio in real time, thus enabling an operator to monitor the lethality of ongoing industrial heat processes. The concept is demonstrated with published survival data of C. botulinum, for which the Weibullian and log‐logistic models served as primary and secondary models, respectively. The safety factor according to the proposed method is in the number of added minutes of processing, beyond the theoretical time needed to reduce the survival ratio of the targeted spores or cells to a level that would produce practical (or commercial) sterility. Copyright © 2006 Society of Chemical Industry 相似文献
118.
Hopko Derek R.; Hunt Melissa K.; Armento Maria E. A. 《Canadian Metallurgical Quarterly》2005,12(4):389
Anxious responding (trait, state, and test anxiety) has a negative impact on overt performance. Researchers have used a unidimensional method of assessing anxiety and performance, although a more informative approach would involve a comprehensive assessment battery and multiple performance tasks. Incorporating this strategy, the authors measured the impact of anxiety on 4 attentional processing tasks. Results revealed that "types" of anxiety symptoms were differentially related to attentional task performance; test anxiety accounted for the most variance in predicting performance on the Wechsler Adult Intelligence Scale-Third Edition (D. Wechsler, 1997) letter-number sequencing and digit-span subtests, trait anxiety and fear of negative evaluation were more significant in predicting Stroop performance, and math anxiety accounted for the largest variance toward understanding Paced Auditory Serial Addition Task (C. W. Lejuez, C. W. Kahler, & R. A. Brown, 2003) scores. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
119.
Yong-Seo Park Seong-Gook Kang Alma Leticia Martinez Ayala Olga Martín-Belloso Shela Gorinstein 《LWT》2006,39(7):748-755
Fresh persimmons were subjected to two different processes: sun-drying during 1 month and dehydration at 60 °C during 12 h. To assess the effect of this process on nutritional and health-related properties of persimmons dietary fibers, minerals, trace elements, polyphenols and the total radical scavenging activities (TRSAs) were determined before and after processing. It was found that the contents of dietary fibers, minerals and trace elements in fresh and dried persimmons fruits were comparable. Total polyphenols in fresh persimmons was higher than in dried fruits (1.3 vs. 0.9 and 0.8 mg/100 g FW, respectively) and percentage of inhibition was higher than in dried fruits (70% vs. 59% and 55% and 58% vs. 53% and 46% for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) [ABTS] radicals, respectively (P>0.05 in all cases). In conclusion: (1) the differences in the contents of dietary fibers, minerals and trace elements in fresh and dried persimmons are not significant; (2) the contents of polyphenols and the level of the TRSA are higher in fresh persimmons than in dried fruits; however, both variables are also high in dried persimmons; (3) when fresh fruits are not available, proper dried persimmons could be used as a valuable substitute. 相似文献
120.
Exfoliation and related microstructures in 2024 aluminum body skins on aging aircraft 总被引:3,自引:0,他引:3
Maria Posada L. E. Murr C. -S. Niou D. Roberson D. Little Roy Arrowood Debra George 《Materials Characterization》1997,38(4-5):259-272
Exfoliation, a directional attack along elongated grain boundaries, has been examined in some detail in rolled 2024 aluminum sheet and plate for KC-135 aging aircraft body skin samples utilizing optical (light) metallography, scanning electron microscopy, and transmission electron microscopy. A detailed analysis and comparison of precipitates within the grains and in the grain boundaries were performed, as well as an examination of elemental depletion profiles across grain boundaries. These observations suggest that corrosion-related anodic sites play a far less significant role in the propagation of exfoliation than do the hard corrosion products creating wedging stresses within the elongated grain boundaries, which seem to demonstrate unique and unusual structural or energetic features or both. 相似文献