Relative Age,Class Assignment,and Academic Performance: Evidence from Brazilian Primary Schools

Students in Brazil are typically assigned to classes based on the age ranking in their cohort. I exploit this rule to estimate how fifth‐grade students’ achievement in mathematics is affected when they are in classes with older peers. I find that being assigned to the older class leads to a drop in maths scores of about 0.4 of a standard deviation for students at the cut‐off. I provide evidence that heterogeneity in age is an important factor behind this effect. Information on teaching practices and student behaviour sheds light on how class heterogeneity harms learning.     

不应用西方经济学理论阐释生产要素按贡献参与分配的原则

我国实行“按劳分配与生产要素按贡献参与分配相结合”的政策符合我国初级阶段所有制结构状况,在理论上予以论证是必要的.但已有的讨论局限于生产要素贡献是指价值创造或财富创造或所有权的论争.实际上,“按生产要素分配”只是一个粗浅的表面现象,在历史上从来没有真正存在过.因此,有关研究和讨论应关注从现实中揭示所谓“按生产要素分配”的真实内容,以为实践我国现阶段的分配政策提供非学究式的、有用的指导.     

The Evolution of Knowledge Objects at the Primary School: A Study of the Material Concept as it is Taught in France

Institutional relations to knowledge objects at the primary school are time-fluctuant and therefore closely linked to the development of institutions. Building up the concept of material implies several sciences and technologies in overlapping epistemological fields. The questions of transposition and appropriation associated to the concept at primary school are a true challenge for the technology educator. This article shows the different connections between the French education and concept formation about materials at the primary school.     

新时期我国农产品物流技术与装备发展探析

本文认为,现代农产品物流技术与装备的发展程度是衡量一个国家物流现代化程度的重要标志,它作为一个内生因素,可以改变传统的农产品物流模式,更好地保证农产品物流的顺利运转。而目前我国农产品物流技术与装备的发展还远远不能满足农业和农村经济的需要,基础设施建设投入太少,信息系统不完善,行业标准不统一,企业内外存在着多种矛盾。文章提出,为促进农产品物流技术与装备的发展,除了要在农产品物流技术与装备选择方面遵循适用性、经济性、协调性、渐进性等四大原则外,还应重点加快物流基础设施建设,逐步改造、提升现有技术装备;加快信息交换平台建设,提高物流信息化、系统化水平;建立物流技术与装备评价指标体系,加强对全过程的质量监督;政府出台相关支持政策,加大对研究与开发的投入力度。     

关于劳动收入初次分配公平的几个问题

劳动收入初次分配是国民收入初次分配的基本组成部分。关于劳动收入初次分配的公平有许多问题需要探讨。劳动收入初次分配公平包括分配权利、分配机会、分配条件、分配规则、分配过程和分配结果公平等多方面的内容,其中分配规则、分配过程的公平特别重要。在劳动收入初次分配中必须将公平与效率置于同等重要的地位。分配是否公平虽然无法摆脱个人主观判断,但是可以通过各种客观的内在和外在尺度进行判断。分配公平应该是社会的基本价值诉求。要实现分配公平,既需要整个社会坚持公平的价值取向,集合各种促进劳动收入初次分配公平的因素和机制,也需要遏制各种导致劳动收入初次分配不公平的因素和机制。     

Investigation on Dumpling Issue——Remarks from China's State Council Information Office

From the very beginning of the dumpling incident,China has pav great concernontheoroblem and moved rapidly to find the reason and take further actions.Series of investigations carried in both countries by co-organized experts'team received a primary fruit as the true picture of the incident.Each time,China IS sparing no effort responsibly to solve the products quality dilemma,which other countries face in the same.     

地下室楼盖结构选型综合分析

本文针对地下车库顶板,常用柱网,8.4m×8.4m的楼盖,运用理正工具箱、PKPM软件进行了构件配筋计算,对各种楼盖结构进行了比较,并对其进行经济性及其它指标分析。     

隧道初期支护

随着我国交通建设的快速发展,地铁、铁路等施工项目越来越多,使得隧道施工变得很重要。初期支护在隧道施工中占据着重要的角色,应加强隧道初期支护施工技术。杨家庄隧道工程地质复杂、工期紧张、施工条件恶劣,本文对该隧道的初期支护施工技术进行介绍,给类似工程施工提供了参考依据。     

海南省中小学足球运动SWOT分析与研究——以海南省儋州市中小学为例

本文运用SWOT分析法对海南省中小学足球运动推广与发展的内部因素(优势和劣势)和外部环境(机遇和威胁)进行分析。