The fastest kinetics of lamellar disintegration (predicted duration of 44 min) in AISI 1080 steel is obtained with a novel approach of incomplete austenitisation-based cyclic heat treatment involving forced air cooling with an air flow rate of 8.7 m3 h?1. A physical model for process kinetics is proposed that involves lamellar fragmentation, lamellar thickening, divorced eutectoid growth and generation of new lamellar faults in remaining cementite lamellae in each cycle. Lamellar fragmentation is accentuated with faster rate of cooling through generation of more intense lamellar faults; but divorced eutectoid growth is ceased. Accordingly, as compared to still air cooling, much faster kinetics of lamellar disintegration is obtained by forced air cooling together with the generation of much smaller submicroscopic cementite particles (containing more proportion of plate-shaped non-spheroids) in divorced eutectoid region. 相似文献
Two experiments examined the ability to remember the vocal tempo and pitch of different individuals, and the way this information is encoded into the cognitive system. In both studies, participants engaged in an initial familiarisation phase while attending was systematically directed towards different aspects of speakers’ voices. Afterwards, they received a tempo or pitch recognition task. Experiment 1 showed that tempo and pitch are both incidentally encoded into memory at levels comparable to intentional learning, and no performance deficit occurs with divided attending. Experiment 2 examined the ability to recognise pitch or tempo when the two dimensions co-varied and found that the presence of one influenced the other: performance was best when both dimensions were positively correlated with one another. As a set, these findings indicate that pitch and tempo are automatically processed in a holistic, integral fashion [Garner, W. R. (1974). The processing of information and structure. Potomac, MD: Erlbaum.] which has a number of cognitive implications. 相似文献
Our use of language depends upon two capacities: a mental lexicon of memorized words and a mental grammar of rules that underlie the sequential and hierarchical composition of lexical forms into predictably structured larger words, phrases, and sentences. The declarative/procedural model posits that the lexicon/grammar distinction in language is tied to the distinction between two well-studied brain memory systems. On this view, the memorization and use of at least simple words (those with noncompositional, that is, arbitrary form-meaning pairings) depends upon an associative memory of distributed representations that is subserved by temporal-lobe circuits previously implicated in the learning and use of fact and event knowledge. This declarative memory system appears to be specialized for learning arbitrarily related information (i.e., for associative binding). In contrast, the acquisition and use of grammatical rules that underlie symbol manipulation is subserved by frontal/basal-ganglia circuits previously implicated in the implicit (nonconscious) learning and expression of motor and cognitive skills and habits (e.g., from simple motor acts to skilled game playing). This procedural system may be specialized for computing sequences. This novel view of lexicon and grammar offers an alternative to the two main competing theoretical frameworks. It shares the perspective of traditional dual-mechanism theories in positing that the mental lexicon and a symbol-manipulating mental grammar are subserved by distinct computational components that may be linked to distinct brain structures. However, it diverges from these theories where they assume components dedicated to each of the two language capacities (that is, domain-specific) and in their common assumption that lexical memory is a rote list of items. Conversely, while it shares with single-mechanism theories the perspective that the two capacities are subserved by domain-independent computational mechanisms, it diverges from them where they link both capacities to a single associative memory system with broad anatomic distribution. The declarative/procedural model, but neither traditional dual- nor single-mechanism models, predicts double dissociations between lexicon and grammar, with associations among associative memory properties, memorized words and facts, and temporal-lobe structures, and among symbol-manipulation properties, grammatical rule products, motor skills, and frontal/basal-ganglia structures. In order to contrast lexicon and grammar while holding other factors constant, we have focused our investigations of the declarative/procedural model on morphologically complex word forms. Morphological transformations that are (largely) unproductive (e.g., in go—went, solemn—solemnity) are hypothesized to depend upon declarative memory. These have been contrasted with morphological transformations that are fully productive (e.g., in walk—walked, happy—happiness), whose computation is posited to be solely dependent upon grammatical rules subserved by the procedural system. Here evidence is presented from studies that use a range of psycholinguistic and neurolinguistic approaches with children and adults. It is argued that converging evidence from these studies supports the declarative/procedural model of lexicon and grammar. 相似文献
This study investigates the interaction between surface and colour knowledge information during object recognition. In two different experiments, participants were instructed to decide whether two presented stimuli belonged to the same object identity. On the non-matching trials, we manipulated the shape and colour knowledge information activated by the two stimuli by creating four different stimulus pairs: (1) similar in shape and colour (e.g. TOMATO–APPLE); (2) similar in shape and dissimilar in colour (e.g. TOMATO–COCONUT); (3) dissimilar in shape and similar in colour (e.g. TOMATO–CHILI PEPPER) and (4) dissimilar in both shape and colour (e.g. TOMATO–PEANUT). The object pictures were presented in typical and atypical colours and also in black-and-white. The interaction between surface and colour knowledge showed to be contingent upon shape information: while colour knowledge is more important for recognising structurally similar shaped objects, surface colour is more prominent for recognising structurally dissimilar shaped objects. 相似文献
“Upfixes” are “visual morphemes” originating in comics where an element floats above a character’s head (ex. lightbulbs or gears). We posited that, similar to constructional lexical schemas in language, upfixes use an abstract schema stored in memory, which constrains upfixes to locations above the head and requires them to “agree” with their accompanying facial expressions. We asked participants to rate and interpret both conventional and unconventional upfixes that either matched or mismatched their facial expression (Experiment 1) and/or were placed either above or beside the head (Experiment 2). Interpretations and ratings of conventionality and face–upfix matching (Experiment 1) along with overall comprehensibility (Experiment 2) suggested that both constraints operated on upfix understanding. Because these constraints modulated both conventional and unconventional upfixes, these findings support that an abstract schema stored in long-term memory allows for generalisations beyond memorised individual items. 相似文献
The experiment was set-up to investigate the mechanisms of postural control by manipulating the base of support angle, using tilted platform wedges. The primary focus was to analyze the coupling of the motion of the center of mass (CoM) and the center of pressure (CoP), and the motions of the leg joints considered as individual components and synergies. The CoM-CoP coupling (both medio-lateral and anterioposterior) was preserved (∼0°) across all tilted platform angles (35°, 30°, 20°, 10° Down, 0° Flat and 10°, 20°, 25° Up), reflecting an in-phase pattern. There was high coherence (∼1) for CoM-CoP in the lower frequency range, whereas contrarily the hip, knee and ankle pair-wise couplings had values ranging between (0.4 and 0.7) across the different platform angle conditions. These findings are consistent with the view that the local pair-wise coupled variables of Hip, Knee and Ankle motions adaptively self-organized to preserve the CoM-CoP in-phase coupling at equilibrium over the baseline (0° Flat) platform condition and all other tilted platform angles. The findings support the hypothesis of CoM-CoP coupling acting as a collective variable that provides the structural integrity of the system for upright quiet standing across the platform angle conditions. 相似文献
Objective: The extent to which positive (PA) and negative (NA) affect conjointly impact well-being is not yet well understood. Additionally, research investigating the role of affectivity in maintaining well-being among ethnic and racial minorities is scant. The current research demonstrates how polynomial regression and response surface methodology (PR and RSM) may be used to better understand how PA and NA jointly influence stress and well-being.
Design: In Study 1, 291 African-American undergraduates (Mage = 22.91, SD = 6.91; 67% female) completed measures of affectivity and psychological well-being. In Study 2, a community sample of 117 African-Americans (Mage = 31.87, SD = 13.83; 69% female) completed affectivity measures and a laboratory-based social stressor task to assess links between affectivity and salivary cortisol reactivity.
Main outcome measures: Study 1 included life satisfaction, perceived stress and self-reported depressive symptoms. Study 2 included salivary cortisol reactivity.
Results: Across both studies, PA ascendency (i.e. high PA combined with low NA) was associated with better well-being, while NA ascendancy (i.e. high NA combined with low PA) was associated with poorer outcomes.
Conclusion: PR and RSM may provide new insight into the conjoint influence of PA and NA on health and well-being. We discuss potential implications for affectivity research, including race-related explorations. 相似文献
Black adolescents in low-income communities are at increased risk of developing mental health problems due to the impact of cumulative poverty-related stressors and racial discrimination, yet Black youth have relatively low rates of mental health service utilization, resulting in significant unmet need. The Coping With Stress (CWS) Course is an evidence-based, cognitive behavioral intervention that has been shown to reduce the incidence of anxiety, mood, and conduct problems among predominantly White samples, as well as Asian and Latinx youth. In the past 25 years since the CWS Course was introduced, Black adolescents have either been severely underrepresented or conspicuously absent from program evaluation research on the CWS Course, with few exceptions. The purpose of this article is threefold: (1) to justify the need for cultural adaptations to the CWS Course for Black adolescents from low-income communities, (2) to describe the scientific basis for the specific surface structure and deep structure modifications made to the culturally adapted version of the CWS Course, known as Resilient In spite of Stressful Events or RISE, and (3) to illustrate the deep structure adaptations with a vignette drawn from implementation of the RISE program with Black adolescents in a low-income, urban community. 相似文献
The present study aims to assess how the processing of basic visual perceptual (VP) components (length, surface, orientation, and position) develops in typically developing (TD) children (n = 215, 4–14 years old) and adults (n = 20, 20–25 years old), and in children with cerebral palsy (CP) (n = 86, 5–14 years old) using the first four subtests of the Battery for the Evaluation of Visual Perceptual and Spatial processing in children. Experiment 1 showed that these four basic VP processes follow distinct developmental trajectories in typical development. Experiment 2 revealed that children with CP present global and persistent deficits for the processing of basic VP components when compared with TD children matched on chronological age and nonverbal reasoning abilities. 相似文献