Electrical conductivity of Nd and Ce co-doped Gd2Zr2O7 ceramics

In this study, (Gd_{1? x} Nd _x )₂(Zr_{1? x} Ce _x )₂O₇ (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5.     

Demonstration and interpretation of ‘scutoid’ cells formed in a quasi-2D soap froth

ABSTRACT

Recently a novel type of epithelial cell has been discovered and dubbed the ‘scutoid’. It is induced by curvature of the bounding surfaces. We show by simulations and experiments that such cells are to be found in a dry foam subjected to this boundary condition.     

Exploring the determinants of dual goal facilitation in a rule discovery task

Wason's standard 2-4-6 task requires discovery of a single rule and leads to around 20% solutions, whereas the dual goal (DG) version requires discovery of two rules and elevates solutions to over 60%. We report an experiment that aimed to discriminate between competing accounts of DG facilitation by manipulating the degree of complementarity between the to-be-discovered rules. Results indicated that perfect rule complementarity is not essential for task success, thereby undermining a key tenet of the goal complementarity account of DG facilitation. The triple heterogeneity account received a good degree of support since more varied triple exploration was associated with facilitatory DG conditions, in line with this account's prediction that task success is associated with the creative search of the problem space. The contrast class account (an extension of Oaksford & Chater's, 1994, iterative counterfactual model) was also corroborated in that the generation of descending triples was demonstrated to be the dominant predictor of DG success. We focus our discussion on conceptual ideas relating to the way in which iterative counterfactual testing and contrast class identification may work together to provide a powerful basis for effective hypothesis testing.     

延迟满足情境中2岁儿童对行为的自我控制能力和延迟策略的使用

以2岁儿童为被试,探讨其在延迟满足情境中的自我控制能力发展的状况。结果表明:(1)2岁儿童已具有一定程度的自我控制能力,个体差异显著,性别差异不显著;(2)2岁儿童已能使用一定的延迟策略,包括问题解决、分心、寻求安慰、消极等待、寻求他人帮助、回避等,其中使用频率最高的是分心策略;(3)不同的策略对延迟时间有着不同的影响;(4)儿童对策略的使用不会因延迟满足情境的不同而出现显著差异。     

初中词汇理解能力量表的编制

应用项目反应理论为初中各年级编制了词汇理解能力的测验,其中包含了１４３个多项选择的词汇项目,经过反复预测和大规模的正式测试,证关了这三个测验的量表拟全于２ＰＬ模型,项目特征曲线拟合度良好的项目占全体项目数９０％以上,能力的一维性也得以确认,经等值化后,各年级的区分度均值分别为０．６１（初一）,０．５９（初二）,０．５５（初三）难度均值分别为－１．６１,－１．３０,－０．５６。     

Psychological Interventions and Genetic Testing: Facilitating Informed Decisions About BRCA1/2 Cancer Susceptibility

Genetic testing for inherited cancer susceptibility, based on the recently identified. BRCA1 and BRCA2 genes, will soon be available on a large scale. However, at present, genetic test results do not lead to clearly indicated diagnostic or preventive measures, and the nature of the psychological impact of BRCA1/2 testing is still largely unknown. This uncertainty, combined with preliminary evidence suggesting significant individual differences in reactions to genetic susceptibility feedback, constitutes a unique challenge for any individual contemplating such testing. We outline the nature of this challenge and then propose an intervention strategy designed to help individuals make deeply processed and psychologically well-informed decisions with regard to their genetic susceptibility. The intervention is guided by recent research findings and theory on the cognitive–emotional processing of cancer-risk information. Specifically, the goal is to prepare the individual for genetic testing by (1) cognitively and emotionally activating, or preliving, the individual's potential reactions to testing feedback; (2) facilitating accurate appraisal of the individual's cognitive–emotional reactions; and (3) enabling the individual to process these reactions through the use of well-established clinical techniques.     

Inducing ordinal and cardinal representations of the first five natural numbers

The prediction that the ordinal property of natural number symbols (using these symbols to represent the terms in an ordered progression) is more easily learned than the cardinal property of natural number symbols (using these symbols to represent the manyness of collections) was examined in this experiment. Preschoolers who evidenced no proficiency with either the ordinal or cardinal properties of natural number symbols were trained to acquire these properties via simple feedback. Both properties proved to be trainable. The most important findings were that the ordinal property was much easier to train than the cardinal property, ordinal training effects were more durable across a 1-week interval than cardinal training effects, and ordinal training appeared to transfer better than cardinal training.     

Positive contrast obtained in reacquisition following interpolation of nonreinforced or partially reinforced trials

Two experiments investigated the effects of shifting from either nonreinforcement or partial reinforcement (PRF) to continuous reinforcement conditions (CRF). In the first experiment, three groups of rats were given food reinforcement under CRF conditions in a runway followed by regular extinction trials (RE), extinction trials where Ss were delayed for 30 sec before entering the empty goal box (DE), or CRF trials where Ss were delayed for 30 sec before entering the baited goal box (DF). Then all Ss were run on the delayed reinforcement condition (DF). In the final delayed reinforcement condition, group DE ran significantly faster than group DF, reflecting positive contrast. In the second experiment, four groups of rats were trained in a runway to receive either 4% or 18% sucrose reinforcers under either PRF or CRF conditions. Then all Ss were transferred to a Skinner box and bar presses were continuously reinforced, with each S continuing to receive the same sucrose concentration as before. The former PRF Ss, regardless of the reinforcer, bar pressed at a significantly higher rate in the Skinner box than the former CRF Ss. The evidence seemed to favor the view that the effectiveness of a reinforcer is not an absolute, unchanging quantity but rather depends on the historical context in which the reinforcer occurs.     

Sibling Death and Adult Maladjustment Indices: A Brief Report

While symptoms of grief pose the most immediate psychological concern in the aftermath of sibling death, emerging research suggests that distal correlates may include strained interpersonal relations and externalized forms of psychological distress. College students with a history of Sibling Loss (n = 36), Parental Loss (n = 32), or No Loss (n = 367) were compared on the Minnesota Multiphasic Personality Inventory (MMPI-2). Sibling Loss was associated with higher Psychopathic Deviate (Pd; d = .62) and Hypomania (d = .42) scores. The relative risk (RR = 2.96) of a Pd elevation (T > 65) was higher after sibling death.