Play behavior and motor development in juvenile Belding’s ground squirrels (<Emphasis Type="Italic">Spermophilus beldingi</Emphasis>)

We evaluated the relationship between play behavior and motor development in juvenile Beldings ground squirrels (Spermophilus beldingi). We observed the social play behavior of juvenile S. beldingi during their primary play period and conducted motor skills tests at the beginning and end of the play period. We also placed different-sized boxes in juveniles natal areas during the play period and observed box climbing behavior to assess the difficulty of non-social play tasks undertaken by juveniles. Rates of social play were greater in heavy compared to light individuals, supporting the idea that juveniles must selectively allocate available energy among competing demands such as growth and play behavior. Juveniles played almost exclusively with littermates; however, they did not play at equal rates with all partners. Rather, they tended to have one preferred partner and to devote significantly less time to playing with each additional partner, indicating that stability and familiarity are important in social play interactions. Motor skill levels at the end of the play period were greater among juveniles who played with many compared to few partners, suggesting that exposure to a variety of play interactions helps facilitate motor development. Improvement in motor skills was greater among juveniles who played at high compared to low rates, had several compared to few male play partners, and engaged in several compared to few play bouts with male partners, suggesting that elements of play with male partners prominently influence motor development. The partner with whom males played at the highest rate tended to be male, and rates of social play were highest in male biased litters, raising the possibility that improvement in motor proficiency arising from play with males may be especially important for young males. The size of experimental boxes that juveniles climbed increased during the play period, supporting the idea that individuals choose play tasks that pose the greatest challenge.Communicated by T. Czeschlik     

开发中国模式的煤矿事故管理信息系统

开发中国模式的煤矿事故管理信息系统，必须从我国煤矿管理体制和其生产特点出发，把安全生产的管理方法、管理内容和管理对象紧密地与信息系统结合在一起，采取系统模式；运用“数据”、“模型”、“方法”三位一体的信息库管理和非计算机专业用户的汉字屏幕菜单设计以及多样适用的输出格式等技术措施，促进决策的科学化，以便对煤矿井下安全生产情况进行指挥、监督。     

工业生产粉尘爆炸预防和缓解──近期研究与发展综述

本文包括三个方面，即工业粉爆的基础研究、应用研究以及粉尘点人性和可爆性。基础研究包括粉尘云的形成和点火，火焰的传播以及粉煤产生的冲击波。工业预防措施包括惰化和消除点火源。缓解的方法包括隔爆、泄爆、部分惰化、抑爆和全封闭。基础研究和应用研究相互促进。计算机模拟模型可能成为非常有效的方法，也可用于专家系统。     

The concept of delay in development control

This paper discusses the phenomenon of delay in development control. The Government's stress on minimising delay, and the crude measurement used, are contrasted with a discussion of the causes and the accurate measurement of delay. It is suggested that ‘delay’ is a strongly value‐laden term, and that local planning authorities are in many cases being criticised for factors wholly outside \ their control. Minimising delay by speeding decision‐making may not be altogether beneficial to society.     

中国消防科技现状与发展

本文介绍了中国消防事业发展的宏观概况；着重从消防科技实力、科研设施、科技成果应用即发展国际间消防科技合作等方面，回顾了近十年来中国消防科技发展成就；展望了中国在今年后十年内消防科技面临的任务；阐述了进一步加强消防科技工作的措施。     

机遇与挑战:21世纪中国可持续发展的取向

本文通过对我国改革开放以来20多年的经济发展与生态环境状况的全面分析，指出我国未来可持续发展可能面临的挑战和机遇；并根据我国现阶段的经济发展水平以及经济发展与资源环境的倒U字型曲线关系．提出了我国未来可持续发展应该采取的政策措施。     

中国环境管理的发展趋势

本文从环境管理的必然性分析入手,提出了源头控制第一个层次和第二个层次的内容、方法和措施。     

关于建设用地分类管理及污染场地分级管理的建议

通过分析污染场地与建设用地的关系,从土地管理的"建设用地"里界定社会和公众关心的环境问题—"污染场地"的管理范畴,提出建设用地分类管理思路。基于我国污染场地分级管理需求分析,借鉴发达国家和地区的污染场地分级管理情况,提出我国闲置污染场地分级管理制度设计设想,国家确定优先管控名录,对优先管控名录内外场地进行中央和地方的事权划分和管理层级确定。     

论空间规划的“三个空间”与“两个边界”

通过梳理与总结各类具有空间性质的规划中提及的管控空间类型,分析了各类空间性规划在制度与实践中存在的问题,对空间规划的重点内容即生产空间、生态空间、生活空间以及保护边界和开发边界的对象进行了初步划分,并且对"三个空间"和"两个边界"的特征进行了初步归纳。     

中国综合环境经济核算的最新进展与趋势

分析了综合环境经济核算的国际经验,综述了我国综合环境经济核算的最新研究和实践进展,建议我国要加快完善核算技术方法体系,继续深入开展试点研究,加快建设完善的核算制度,适应国际潮流,建立与国际接轨的综合环境经济核算制度。争取用10~15年的时间基本建立完善的综合环境经济核算制度。