Thermal effects on infiltration of a solubility-sensitive volume-memory liquid

As the ion density at a solid–liquid interface changes, the interfacial tension varies accordingly, which can lead to a large energy density output, particularly when amplified by the high specific surface area of a nanoporous material. This concept is validated by the results of a controlled-temperature infiltration experiment on a hydrophobic zeolite immersed in a saturated aqueous solution of sodium acetate. As the temperature changes, the sodium acetate concentration varies significantly, which in turn causes a variation in infiltration pressure. Since the infiltration and defiltration are reversible, under the working pressure, this system exhibits a volume memory characteristic, with a non-monotonic temperature–volume relationship.     

EXPERIMENTER CALCULATION ERRORS: A POTENTIAL FACTOR AFFECTING INTERPRETATION OF RESULTS1

Following a study of socially withdrawn children, it was noted that checks of experimenter calculations indicated discrepancies. The present study investigated the magnitude and direction of experimenter errors in data computations. Two full-time research assistants, who served as experimenters, processed the behavioral observation data. These experimenters were referred to as the subjects in this study. Standard data values, against which the subjects' computations were compared, were established by two other research assistants and a computer staff. The results indicated that experimenters' original data values disagreed with the standard data values. The daily errors showed considerable variability for both experimenters. The specific factors accounting for this variability could not be identified, although frequency of experimenter responses required to obtain rate and duration data, time spent calculating, and complexity of task were suggested as possible contributing variables. While disagreements occurred across all experimental days, the magnitude of differences was generally small. An examination of direction of differences in both experimenters' data showed no systematic trends in favor of the experimental hypothesis. Rather, there appeared to be a trend in the other direction. This study suggests that the same research decisions would have been made during the original investigation using either set of data.     

Gender Differences and Cognitive Correlates of Mathematical Skills in School-Aged Children

Published information concerning the influence of gender on mathematical ability tests has been controversial. The present study examines the performance of school-aged boys and girls from two age groups on several mathematical tasks and analyzes the predictive value of a verbal fluency test and a spatial test on those mathematical tasks. More specifically, our research attempts to answer the following two questions: (1) Are gender differences in mathematical test performance among children interrelated with age and (2) do verbal and spatial nonmathematical tests mediate gender effects on mathematical test performance? Two hundred and seventy-eight 7- to 10-year-old children and 248 13- to 16-year-olds were selected from schools in Colombia and Mexico (231 boys and 295 girls). The age effect was found to be significant for all measures, with scores improving with age. Results showed that boys and girls in both age groups scored similarly in most subtests, but that differences emerged in the performance of mental mathematical operations and in resolving arithmetical problems. In the latter – but not in mental math – older boys outperformed older girls, whereas no gender differences were observed in the younger groups. After controlling for age, it was found that the spatial test was, indeed, a significant mediator of gender effects, while the verbal task was not.     

Many-body potential for nitrogen in α-iron

N atom is one of the most frequent foreign interstitial atoms in α-iron along with C atoms. The Fe–C potential has been well-developed and can reproduce many significant interactions of C with point defects present in α-iron. However, there exists no satisfactory Fe–N potential to describe the interactions of N with point defects. Here, we develop a many-body potential for N in α-iron. The potential parameters are determined by fitting to ab initio data, which includes energetics, configurations, and relaxations of Fe atoms close to N atom. This potential successfully describes the interactions of Fe–N across a wide range of defect environments. The potential employs the embedded atom method form and hence is appropriate for large-scale molecular dynamics simulation.     

青老年组不同难度下心算活动的脑功能磁共振成像研究

应用功能磁共振成像技术研究不同心算难度下脑区的活动以及年龄的影响。14名志愿者（20～29岁青年和60～69岁老年被试各7名）参加了该实验。实验任务为2个难度水平的连续减法心算,分别为1000—3和1000—17。结果表明：（1）心算加工激活了额叶和顶叶的许多脑区;（2）大脑左半球是心算加工的优势半球,但随着心算难度加大,大脑一侧化程度下降,而年老加剧了这一趋势;（3）青年组进行简单心算（1000—3）时,额中回未见明显激活,而老年组进行简单心算时,该脑区被明显激活。总体上,额叶和顶叶在心算活动中起着重要作用,而任务难度和年龄对心算加工时脑活动的影响以额中回区最为明显。     

Mathematical Abilities in Elementary School Children with Autism Spectrum Disorder

Although clinical practitioners often express concerns about the mathematical functioning of children with autism spectrum disorder (ASD), the field of mathematics remains a relatively unexplored topic in individuals with ASD. Moreover, research findings are fragmentary and hold inconclusive results. The present study aimed to examine whether grade 1 (aged 6–7 years) to 4 (aged 9–10 years) elementary school children with ASD scored significantly different from age‐adequate norms on mathematics. To this end, a multi‐componential approach of mathematics was used. Four domains of mathematics were assessed in 121 children with ASD: procedural calculation, number fact retrieval, word/language problems, and time‐related competences. All children attended general education classrooms, following the standard curriculum, and were coached by integrated educational services. Children with ASD showed a strength in word/language problems in second and fourth grade. There was evidence of a weakness for procedural calculation in first grade and for time‐related competences in first and third grade. In all other cases, average scores were shown. As such, results revealed a profile of strengths, average abilities, and weaknesses in mathematics and highlighted the importance of focusing on different domains of mathematics. Because a high variability in mathematical performance could be observed, we recommend an individual assessment when considering the mathematical trajectory of children with ASD. Copyright © 2015 John Wiley & Sons, Ltd.     

计算的脑机制研究进展

采用计算任务来探讨脑机制已成为国外研究大脑活动的重要领域。该文阐述了神经心理学和脑成像领域有关计算的脑机制研究。神经心理学及脑损伤的研究结果表明,大脑两侧顶下小叶和左前额叶与计算加工有关。ERP、PET和fMRI脑成像研究结果显示,数字命名与比较、心算、精算和估算等不同计算任务,其所激活的脑部位有所差异,但是大脑两侧顶下小叶和左前额叶可能是计算加工的主要脑部位。由于研究材料、方法和程序的不同,大脑皮层的广泛区域都有可能参与计算加工。