Ductility enhancement in nanoglass: role of interaction stress between flow defects

Using a thermodynamically consistent non-local plasticity model, the mechanistic origin of enhancement in ductility and suppression of dominant shear banding in nanoglasses (NGs) is analysed. It is revealed that the interaction stress between flow defects plays a central role in promoting global plasticity of NGs. Specifically, we find that the intrinsic length associated with this stress provides a scaling for the shear band width and its coupling with grain size governs the level of enhancement in the deformation behaviour of NGs. The present work may provide useful insights in developing highly ductile NGs for practical engineering applications.     

A selection of maximal elements under non-transitive indifferences

In this work we are concerned with maximality issues under intransitivity of the indifference. Our approach relies on the analysis of “undominated maximals” (cf., Peris &; Subiza, 2002). Provided that an agent’s binary relation is acyclic, this is a selection of its maximal elements that can always be done when the set of alternatives is finite. In the case of semiorders, proceeding in this way is the same as using Luce’s selected maximals.We present a sufficient condition for the existence of undominated maximals for interval orders without any cardinality restriction. Its application to certain types of continuous semiorders is very intuitive and accommodates the well-known “sugar example” by Luce.     

核心价值体系:社会资本的支撑性要素

从伦理学的角度看,社会资本是一种以社会交往为载体,通过信任规范机制以及成型化关系网络产生社会信任进而配置社会资源的社会活动方式,它既包括社会个体的行为方式,更折射社会整体的价值体系。社会资本生存并服务于人类的社会关系和交往活动。社会交往自身特质和社会资本匮乏使得核心价值体系构成了社会资本的支撑性要素和价值基础,指导着社会资本的合理发展。把核心价值体系纳入社会资本建设体系有助于社会资本的积聚和核心价值体系功效的发挥。核心价值体系作为社会资本的支撑性要素,有助于整合人们的认知、情感、意志和行为,有助于达成共识、减少纷争、扩大交流、增进互信与和谐。形成合理融洽的社会资本结构体系和良性互动的社会运行机制。     

部件类型还是交错关系信息的习得促进问题解决？

本研究旨在探讨知觉组块中部件类型和空间交错关系信息的学习是否促进问题解决。研究采用学习-测试范式,71名有效被试（女性25名,平均年龄=20.51±2.35岁）先学习解答组块破解问题然后进行测试。研究分别在学习和测试阶段基于组块破解任务操纵了部件类型（汉字水平vs.笔画水平）和空间交错关系（交错vs.非交错）。学习阶段,被试分别在四组中完成组块破解练习;在测试阶段完成所有四组问题。研究发现,对交错关系信息的学习与利用相对于部件类型信息促进了问题解决：在涉及交错信息的测试任务上,涉及交错信息比非交错信息的学习条件解答率更高,反应时更短;反之则不是。然而部件类型则没有发现类似的促进效应。与此同时,交错关系信息的习得需要对任务的重复操作学习：涉及交错关系信息的组块破解学习成绩在不同任务间并不随时间推移而提高,但会随重复学习次数而提高。     

Short-range ordering of heavy-element columns in nickel-based superalloys

In order to obtain comprehensive performance, heavy elements were added into superalloys for solid-solution hardening. It is found that, rather than adopting random distributions, the heavy atoms prefer to form short-range ordered columns with heavy-element stripes 1–2 nm in length. This is supported by our ab initio calculations. Owing to the strong bonding strength between the refractory elements and nickel atoms, this short-range ordering may be beneficial to the mechanical performances of superalloys.     

鼻腔流场数值模拟与鼻声反射相关性研究

探讨应用鼻声反射测量评估基于CT图像的三维重建人体鼻腔模型的可靠性,并用有限元方法对模型的流场进行数值模拟。基于志愿者CT医学图像,用表面重建的方法对人体鼻腔进行三维重建,并用有限元方法对腔体中气体的流动进行数值模拟及分析;采用鼻声反射仪测试得到志愿者鼻声反射曲线,分别提取并对比两种方法得到的鼻腔多个轴向横截面面积数据。结果显示。两种方法得到的数据有很好的吻合。由此得出结论,所建模型较真实的反映了鼻腔实际解剖结构形态。数值模拟结果可靠,对临床上呼吸道解剖结构与功能相关疾病的诊断、发病机理的深入探讨具有参考价值。     

Alvin Plantinga on the ontological argument

By taking ‘existence in reality’ to be a great-making property and ‘God’ to be the greatest possible being, Plantinga skillfully presents Anselm’s ontological argument. However, since he proves God’s existence by virtue of a premise, “God (a maximally great being) is a possible being”, that is true only if God actually exists; his argument begs the question of the existence of God.     

认知元反应理论--IRT直接应用于多值记分题

0-1记分测验的项目反应理论已经得到广泛的研究和应用.但是,许多测验都含有多值记分题,所以需要将IRT推广到此类情况.从认知理论的观点看,每个0-1记分题(项目)和多值记分题的每个测试点都可同样地看成一个由若干知识点构成的集合,称之为认知元;根据认知元之间存在的关系可以确定各受测者对各试题作出特定答案的概率,从而不需要引用任何其它假设就可将IRT的方法直接应用于含多值记分题的测验.本文应用这一理论分析了某些测验样本,结果表明是可行的.     

高级技工诊断生产活动的认知策略的汇编栅格法研究

本研究采用汇编栅格法探讨了高级技工(专家)诊断人机系统生产活动的认知策略,结果表明:第一,在高级技工的认知结构中,存在着对多因素交互作用下复杂情况进行诊断的认知地图,它以特定方式组合着常见的问题类型和原因特征,是制约技工复杂技能教学成效的关键要素。第二,汇编栅格法是对人机系统中专家的认知结构进行功能模拟的一种有效方法,它不仅在揭示未知的高级技工认知结构时,以其直观的投射方式提供专家启发式策略的新信息,而且在培训和评估复杂技能方面具有可观的应用前景。