阅读材料类型和难度对五年级儿童阅读策略的影响

以34名五年级儿童为被试,采用出声思维法考查了阅读材料类型和难度对儿童阅读策略使用情况的影响。结果发现,被试在记叙文阅读过程中使用的阅读策略种类数和总次数均多于说明文。阅读材料难度对于阅读策略种类数和使用次数没有影响。阅读材料类型和难度都对多个阅读策略的使用次数有影响,但是阅读材料类型和难度对于各阅读策略使用次数的影响并不一致。     

Objecting (to) Infrastructure: Ecopolitics at the Ukrainian Ends of the Danube

Abstract

In southern Ukraine, two hydraulic infrastructures continue to exist despite environmentalist campaigns that have exposed them as fragile, broken, or unprofitable. The Danube–Dnister Irrigation Project, a Soviet mega-project that diverted water from the Danube and turned the Sasyk estuary into a reservoir, receives state funding despite a 1994 ban on its use for irrigation. The Bystre Shipping Canal, built in 2004 despite domestic and international opposition, is losing money but continues to operate. These cases exemplify the material politics of infrastructuring in which infrastructure is understood as an antagonistic process of assembling networks of humans and nonhumans rather than a fixed facility. This approach helps explain how the confluence of unruly coastal matters and the politics of expertise have facilitated the re-embedding of these shipping and irrigation infrastructures’ in bureaucratic networks. These cases show that obduracy and fragility, as well as visibility and invisibility—conditions that figure prominently in infrastructure studies—should be considered in terms of oscillation rather than as ontologically distinct or static conditions. This analysis highlights the limits of the modernist search for scientific certainty in resolving environmental conflicts in Ukraine, and some possibilities to experiment politically with new decision-making procedures. This account can thus point beyond reform impulses that re-enact modernist narratives of progress within a strict nature-society divide.     

A new allotropic structure of silver nanocrystals nucleated and grown over planar polymer molecules

Polymer molecules of polyvinyl alcohol (PVA) serve as a good Ag⁺?→?Ag⁰ reducer as well as a template to produce Ag⁰ nanocrystals of anisotropic shapes. Thin Ag–PVA films (50–100?µm thick) were prepared by carrying out the reaction in aqueous PVA (under heating conditions) and then spin casting the sample in this shape. A topotactic Ag⁺?→?Ag⁰ reaction and in-situ Ag⁰ growth occur in support over the PVA molecules (as per the local structure and Ag⁰–PVA interactions) of elongated surfaces. The Ag⁰ state is confirmed with 3d _5/2 and 3d _3/2 XPS signals of 368.37 and 374.13?eV binding energies, respectively. As analyzed with X-ray diffraction, it is a new allotrope with an orthorhombic structure, lattice parameters a?=?0.8535, b?=?0.8410?nm and c?=?0.4119?nm, and density ρ?=?9.69?g?cm^?3. On heating in air, the well-known cubic structure develops, a?=?0.4082?nm (ρ?=?10.53?g?cm^?3) after 150°C, whereas a?=?0.4071?nm (ρ?= 10.61?g?cm^?3) after 300°C for 2?h. According to proposed models, it is a vacancy-stabilized allotrope, which evolves from multiply twinned particles.     

Nd2O3 : Eu3+ nanocrystalline phosphor–a new potential thermoluminescing material for dosimetry

Nanoparticles of trivalent Eu³⁺-doped Nd₂O₃ phosphors have been prepared using a low-temperature solution combustion method with metal nitrate as precursor and oxalyldihydrazide as a fuel at a fairly low temperature (<500°C) and in a very short time (<5 min). A powder X-ray diffraction pattern reveals that cubic Nd₂O₃ : Eu³⁺ crystallites are directly obtained without the requirement of further calcinations. The crystallite size, evaluated from Scherer's formula, was found to be in the range of 20–30 nm. The microstructure and morphology were studied by scanning electron microscopy, which showed the phosphor to be foamy and fluffy in nature. Thermoluminescence characteristics of the Nd₂O₃ : Eu³⁺ have been studied using gamma irradiation. These demonstrate that the phosphor is suitable for use as a dosimeter.     

Nanocracks at grain boundaries in nanocrystalline materials

A theoretical model is proposed to describe the generation and evolution of nanoscale cracks (nanocracks) in strained nanocrystalline materials. In the framework of the model, the nanocracks are nucleated and grow along grain boundaries, changing the direction of their growth at triple junctions.     

体验购买与实物购买：概念、测量及其与快乐的关系

体验购买是指为了获得生活经历或经验而进行的购买, 与其相对应的是实物购买, 指的是为了拥有物质类商品而进行的消费行为。这两种购买类型对于个体的快乐有着不同的影响, 体验购买比实物购买更让人感到快乐和愉悦, 其中的原因存在于以下5个方面：体验随时间的推移而改善, 变得越来越美好; 体验与自我的联系更为紧密; 体验购买不易引起社会比较; 体验能够满足基本心理需要, 尤其是关系需要; 体验易于分享。未来研究可以从以下3个方面着手：(1) 探索购买类型对快乐感的长期影响以及对不同取向幸福感的作用, 体验优先的适用范围; (2) 改进现有回忆和想象的研究范式, 提高生态效度; (3) 结合我国实际情况开展购买类型与快乐感的本土化研究。     

尝试提取复杂信息失败的学习：吃一堑长一智？

摘 要：在学习中,提取失败能否产生对知识的有效学习是一个很有意义的研究课题。以事实和概念类知识为实验材料,三个实验采用经典范式探讨了复杂意义条件下的提取失败后的学习效果。结果显示仅在尝试提取事实类题目失败后,促进了知识的保持和迁移;在迁移成绩上延时反馈优于即时反馈的效果。表明尝试提取复杂材料的信息失败后,知识的类型和反馈的时机决定了学习效果。     

制作眼部视听教材相关法律问题的探讨

讨论了在眼部视听教材制作过程中相关的法律问题,正确运用法律、法规保护医患双方合法权益。患者就医时具有肖像权。应用法学理论,结合实践,同意签字后制作眼部视听教材,取得良好效果。     

抽象材料选择任务的表象表征视角

为了探讨在选择任务中表象表征存在的可能性以及抽象材料选择任务困难的原因,该研究设定了材料的内容、规则以及证明规则的要求均完全相同,只是在呈现方式上形象性不同的两种抽象选择任务;然后把两种不同的选择任务分别对数量大致相当的大学生进行了测试。结果发现,不采用类似卡片这种形象性很强的材料呈现方式显著的提高了人们在抽象选择任务中的正确率。实验结果支持了选择任务中表象表征的存在及其为选择任务困难原因之一的观点。