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排序方式: 共有278条查询结果,搜索用时 15 毫秒
1.
Tape casting is a well-established method for manufacturing thin ceramic layers with controllable thickness and porosity. This study investigates the potential of 10Sc1CeSZ material for the electrolyte and anode layers for intermediate-temperature solid oxide fuel cells (IT-SOFC) in an anode-supported cell (ASC) geometry. In order to use La0.6Sr0.4Co0.2Fe0.8 Oxide (LSCF) cathode material, a Gd0.2Ce0.8 Oxide (GDC) barrier layer is needed; however, thermal expansion coefficient mismatch results in delamination of the GDC from the electrolyte during high temperature sintering when fabricated by conventional tape casting procedures. For the first time, ASCs have been manufactured by a five-layer tape casting technique; barrier layer, novel composite layer, electrolyte, anode functional layer, and anode substrate. Ni-ScCeSZ composite cells were tested between 650 and 800°C in H2:N2 fuel (85% H2) on the anode and air on the cathode to yield a maximum power density of .46 W/cm2. These results demonstrate the feasibility of this new five-layer tape casting technique to produce IT-SOFC.  相似文献   
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Food Science and Biotechnology - The use of unconventional sources is very relevant in the food area. In the present study the development of active films with the addition of bioextract (BE) or...  相似文献   
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Networks and Spatial Economics - Advanced attackers use online social networks in order to extract useful information about targeted organizations, including the names of the organization’s...  相似文献   
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This study evaluates the degree of sensitization (DOS) of 304 stainless steel joined by friction stir welding (FSW). Single-loop electrochemical potentiokinetic reactivation tests were performed using a 0.5 mol/L H2SO4 + 0.01 mol/L KSCN solution. Sensitization was promoted by exposition of the stainless steel at temperatures between 400°C and 850°C. The microstructure was characterized using optical microscopy to identify the weld zone and the base metal. The samples treated at 550°C showed the most severe intergranular corrosion. The DOS was lower in the weld zone than in the base metal after heat treatments. This reduction in the DOS for the weld zone indicates that FSW is a beneficial process in joining stainless steel.  相似文献   
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Objective: There is a need for natural history chronic fatigue syndrome (CFS) studies from random, community-based, multi-ethnic populations. Design: The present study examined the course of CFS from Wave 1 to Wave 2, which spanned over a ten year period of time, and, assessed whether socio-environmental and symptomatology factors were associated with CFS status over the ten year period. Results: There was relative stability over time on critical measures of disability, fatigue, support, optimism and coping over time. One cardinal symptoms of CFS, post-exertional malaise, best differentiated the CFS group from the others. By Wave 2, of the original group of 32 individuals diagnosed with CFS, 4 had died, and 24 were found and agreed to be re-evaluated, and of this group, 16 continued to have CFS, 5 developed exclusionary illnesses, 2 were classified as Idiopathic chronic fatigue, and one had remitted. Conclusions: The current study found that over time in a community-based sample, unbiased by help seeking behavior the CFS group remained rather ill with a variety of different conditions over time. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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Long-term aerobic exercise improves cognition in both human and nonhuman animals and induces plastic changes in the central nervous system (CNS), including neurogenesis and angiogenesis. However, the early and immediate effects of exercise on the CNS have not been adequately explored. There is some evidence to suggest that exercise is initially challenging to the nervous system and that the plastic changes commonly associated with chronic exercise may result as adaptations to this challenge. The current experiment assessed levels of apoptosis, angiogenesis, and neurogenesis during the first week of an exercise regimen in the adult rat. The results indicate that exercise rapidly induces these processes in the hippocampus and cerebellum. The temporal pattern of these events suggests that voluntary exercise in the adult rat rapidly and transiently induces apoptosis, followed by angiogenesis. Neurogenesis is an immediate and independent consequence of exercise in the hippocampus that may require the additional metabolic support supplied by angiogenesis. This is the first report of CNS neuronal apoptosis as a consequence of exercise in the adult rat and suggests that this process is a potential mediator of rapid exercise-induced plasticity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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Gastrointestinal nematodes are a global cause of disease and death in humans, wildlife and livestock. Livestock infection has historically been controlled with anthelmintic drugs, but the development of resistance means that alternative controls are needed. The most promising alternatives are vaccination, nutritional supplementation and selective breeding, all of which act by enhancing the immune response. Currently, control planning is hampered by reliance on the faecal egg count (FEC), which suffers from low accuracy and a nonlinear and indirect relationship with infection intensity and host immune responses. We address this gap by using extensive parasitological, immunological and genetic data on the sheep–Teladorsagia circumcincta interaction to create an immunologically explicit model of infection dynamics in a sheep flock that links host genetic variation with variation in the two key immune responses to predict the observed parasitological measures. Using our model, we show that the immune responses are highly heritable and by comparing selective breeding based on low FECs versus high plasma IgA responses, we show that the immune markers are a much improved measure of host resistance. In summary, we have created a model of host–parasite infections that explicitly captures the development of the adaptive immune response and show that by integrating genetic, immunological and parasitological understanding we can identify new immune-based markers for diagnosis and control.  相似文献   
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Maternal depression is associated with problematic parenting and the development of emotional and behavior problems in children and adolescents. While emotional regulatory abilities are likely to influence emotional exchanges between parents and teens, surprisingly little is known about the role of emotion regulation during parent–child interactions, particularly in high-risk families. Respiratory sinus arrhythmia (RSA) has been widely linked to emotion regulatory abilities in recent research, and the current study investigated RSA and maternal depression in relation to dyadic flexibility, as well as mutuality of negative and positive affect displayed during three discussion tasks between 59 mother–adolescent pairs (age 11–17 years). Dyadic flexibility was predicted by the interaction of maternal depression, maternal RSA, and teen RSA, with higher maternal RSA predicting greater dyadic flexibility, particularly in highest risk dyads (i.e., elevated maternal depression and lower teen RSA). Teen RSA interacted with maternal depression to predict mutual negative affect, serving as a protective factor. Finally, maternal and teen RSA interacted to predict mutual positive affect, with maternal RSA buffering against low teen RSA to predict higher mutual positive affect. Results support the role of RSA in affectively laden interactions between parents and adolescents, particularly in the face of maternal depression. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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