Discontinuous precipitation initiated at interphase boundaries in a Zn-rich Zn-6.3 at.% Ag alloy

Discontinuous precipitation in a two-phase Zn-rich Zn-6.3at.%Ag alloy has been studied. It has been shown that the eta/epsilon interphase boundaries have the ability to initiate discontinuous precipitation as do the eta/eta grain boundaries. The back-polishing method is used to show the interconnection between a discontinuous precipitate colony and the eta/epsilon interphase boundary. The reaction front velocity of discontinuous precipitation initiated at the eta/eta grain boundary is 12-90% higher than that of discontinuous precipitation initiated at the eta/epsilon interphase boundary under various ageing temperatures.     

Homogeneous nucleation of dislocation loops under stress in perfect crystals

We present an analysis and results on the homogeneous nucleation of a dislocation loop under stress in a perfect crystal. By using a variational boundary integral method in the Peierls-Nabarro framework, we have determined the saddle-point configurations of embryonic dislocation loops and their associated activation energies under stress levels up to the ideal shear strength. The high-energy barriers under the usual levels of applied shear stresses, differing markedly from the ideal shear strength, confirm the widely held view that thermal motion should play no role in such nucleation. The result provides means for more definitive solutions of fundamental problems involving homogeneous nucleation of dislocation loops and has significant implications for models based on the mechanism of nucleation of dislocations from a perfect crystal.     

Application of the stagnant stage concept for monitoring Mn partitioning at the austenite-ferrite interface in the intercritical region for Fe–Mn–C alloys

The length of the stagnant stage during the new ferrite growth starting from a mixture of austenite and ferrite has been investigated for a Fe-0.17Mn-0.023C (wt%) alloy. It was found that the stagnant stage depends on the thermal path followed to create the mixture, and deduce that the tie-lines for austenite to ferrite transformation are quite different from those for ferrite to austenite transformation. The length of the stagnant stage is determined by the very local partitioning effect at the interface, and it can be used as a tool to monitor the Mn partitioning.     

Understanding scale-dependent yield stress of metals at micrometre scales

The mechanical softening behaviour of micrometre-scale metals (free-standing metal foils and wires) with decreasing either the geometrical or the microstructural scale (i.e. the smaller, the weaker) has recently been reported. Here, we present a mechanism-based model to understand the softening behaviour, which is based on competition between the effects of surface grain relaxation and the interior grain strengthening effect. The model describes well the yield stress of Cu foils with different ratios of the thickness to grain size.     

基因研究中的知情同意之惑

知情同意作为生命伦理的重要原则,在基因研究中同样占据重要的地位,由于基因研究中知情同意的异质性,在基因研究中面临着诸如如何理解其知情同意的异质性、群体知情同意、基因知情与基因隐私、利益冲突等问题.通过分析基因研究中知情同意的特殊性,综合国内外此领域的已有研究,运用理论联系实际的方法,得出结论认为,只有正确区分基因知情与基因隐私的权利主体,用伦理规范来解决利益冲突,在发展中不断完善知情同意,才能够取得科技与伦理的共赢.     

论《淮南子》的墨子观

《淮南子》对墨子持有复杂的政治认识与态度,这在秦汉思想史上具有一定的代表性。从黄老道家的根本立场出发,“批墨”是《淮南子》政治思想的基本主张,但与此同时,《淮南子》也内在地显示出“尊墨”的政治情怀,进而试图对墨子政治思想有所借鉴和汲取,达到“融墨”之理论目的。对待墨子及其政治思想的历史态度,既凸显出《淮南子》立足黄老,融通诸子的博大精神,也彰显出墨子在秦汉政治思想发展中独特的历史影响。     

A study of the greater male variability hypothesis in creative thinking in Mainland China: Male superiority exists

This study tested the greater male variability hypothesis in creative thinking with a Chinese student sample in Mainland China. The Test for Creative Thinking-Drawing Production (TCT-DP) was administered to 627 Chinese adolescent boys (n = 332) and girls (n = 295). Results using the boy/girl variance ratio (VR) generally supported the hypothesis that boys have greater variability than girls in creativity test performance. However, results using the boy/girl ratios from different regions of the creativity score distribution revealed a pattern of male superiority. While boys significantly outnumbered girls in the higher extremes, girls tended to outnumber boys in the central region and the lower extremes. Results from an analysis of the means lent further support to the findings of male superiority. Plausible explanations for greater male variability and male superiority in Mainland China are proposed. The theoretical and practical implications of the findings are discussed.     

El constructo ansiedad en Psicología: una revisión

RESUMEN

Se trata en este artículo de dar una visión sucinta y comprensiva del tratamiento que, desde el ámbito de la Psicología científica, ha recibido el tema de la ansiedad. Casi todas las escuelas, tanto clínicas como experimentales, han intentado dar una explicación, cada cual con su método y de sus principios teóricos a este complejo fenómeno. Aquí se analizarán cuatro enfoques: Psicodinámica y humanística; Experimental motivacional; Psicométrico-factorial; Cognitivo-conductual. También se presenta, al final, de modo sintético, un resumen que trata de integrar las diferentes aportaciones que se han producido en el desarrollo del estudio científico del tema ansiedad.     

Prevalence and associated factors of poly‐victimization in Chinese adolescents

Multiple types of victimization or poly‐victimization (PV) can occur simultaneously during childhood, resulting in outcomes that are detrimental and difficult to reverse. Very few studies have focused on PV in Chinese adolescents. The present study is based on information collected from a stratified cluster sample of 1,561 females and 1,594 males aged 12–18 years living in Shandong Province, China. A self‐administered questionnaire was used to assess background information, the Juvenile Victimization Questionnaire was used to measure the extent of victimization and PV, the Screen for Child Anxiety Related Emotional Disorders was used to measure anxiety levels, and a Depression Self‐rating Scale for Children was used to ascertain depression. A majority of the study sample (66.2%) had experienced at least one form of victimization over the past year. Prevalence of PV was 16.9%, and was significantly higher among males (21.1%) than females (12.5%). Younger ages, one‐child families, and lower socioeconomic status were positively associated with PV. Logistic regression analysis indicated that smoking, alcohol consumption, exposure to pornography, and anxiety‐ and depression‐like symptoms were risk factors of PV. Results of this study highlight the need for further exploration of factors related to the PV of Chinese adolescents.     

Some Normal Extensions of K4.3

This paper proves the finite model property and the finite axiomatizability of a class of normal modal logics extending K4.3. The frames for these logics are those for K4.3, in each of which every point has a bounded number of irreflexive successors if it is after an infinite ascending chain of (not necessarily distinct) points.