Lactation patterns of pinnipeds are not explained by optimization of maternal energy delivery rates

Within pinnipeds, phocids and otariids show differing maternal care strategies. Phocids rear young out of body stores in a yearly cycle with a single stay ashore when the mother fasts while lactating, whereas otariids provision their young by repeated foraging trips to sea alternating with brief stays ashore where they suckle their young. In a previous optimality model, these differences have been interpreted as adaptations based on differing energy requirements of large (phocid) and smaller (otariid) species, and the time budget of the large elephant and the much smaller Antarctic fur seal were correctly predicted. Our refined model—extended to pinniped species of all sizes—predicts lactation strategies to shift from attendance cycles to 1-year cycles with increasing body mass and provides an explanation for the finding that phocid pups are weaned at lower relative mass than otariid pups. However, other predictions do not correspond to empirical findings. In particular, the model does not explain the behavior of large otariids and small phocids. Thus, maternal metabolic requirements alone appear insufficient to explain observed lactation patterns. In the light of our results, we discuss more generally the scope and limitations of optimality models when applied in a comparative framework to a group of related species.     

庭院经济综合评价

针对辽北各类庭院生态系统特点，建立了评价指标体系，并采用序列综合与专家咨询相结合的评价方法，首次对庭院生态系统进行了综合评价，阐述了各项指标在庭院生态系统中的地位和作用。     

Methodological convergence as an issue within environmental cognition research

Two perspectives in the analysis of pointing and mapping tasks as the measure of representations of the large-scale environment are examined. These two perspectives are: (1) an individual difference approach; and (2) a cognitive representational approach. Convergence between methods assessing the same geographical/spatial knowledge is necessary as evidence for the existence of unified cognitive-spatial representations of the environment.Three sets of analyses interrelate performance on pointing and mapping tasks. In the first analysis, a confirmatory factor analytic model is applied to short tests of pointing and mapping accuracy to determine whether one or two factors are needed to account for covariation between the tests. In the second analysis, covariation among errors in pointing and mapping of specific locations is partitioned into general and specific method factors using the Schmid-Leiman procedure. In the third analysis, pointing errors for identical locations within the mapping and pointing tasks are directly compared on the basis of directional errors.The three analyses indicate that: (1) tests of pointing and mapping measure highly related abilities; (2) the targets used in pointing and mapping tasks are of differential importance in identifying general and specific method factors; and (3) there is little or no direct correspondence between directional errors made in pointing tasks and those occurring in mapping tasks for the same locations.When results of the three analyses are examined in relationship to criteria for convergence of pointing and mapping tasks, little evidence is found to suggest that directional errors in these tasks arise from a unified mental representation of the geographical environment. However, substantial predictable individual differences are apparent for both tasks.     

交通建设环评中生物量影响评价指标探讨

随着公路铁路等交通项目的建设,其面临的生态环境压力日益增大,周边地区生物量发生很大变化。本文针对交通建设活动对生物量的影响问题,研究提出一种基于土地利用类型变化的交通建设项目前后生物量变化的评价指标和评价标准,并采用京沪铁路电气化北京-济南段实际工程建设进行实例应用。     

高原湖泊砷污染健康风险评估

以某高原湖泊为例,以湖水中的砷含量类比推算了从该湖泊取水灌溉区域内水稻和蔬菜的砷含量,对稻米、蔬菜和饮水3种暴露途径进行健康风险评估。结果表明,人群通过摄入区域内稻米、蔬菜的致癌风险系数为可接受的致癌风险,饮用湖水的致癌风险系数为不可接受的致癌风险。     

改善环境质量优化经济增长

论述了目前我国环境与经济之间的关系现状及环境优化对经济增长所做出的贡献,说明环境优化经济增长是转变经济增长方式国家战略的必然要求,提出规划环评是促进环境优化经济的重要手段。     

A recursive ecological indicator system for the supply chain of a company

This paper proposes the concept of cumulative eco-intensity with which environmental or sustainability indicators are related to the added value of economic activities. The intensities are passed on recursively from supplier to supplier and thus make it possible to include upstream and downstream effects along the supply and waste disposal chain. The process is applied to whole companies and (by contrast with LCA) not to individual products. At comparatively low expenditure for the individual companies, it allows vertical comparisons along the value-adding chain and horizontal comparisons among companies or production locations. This provides a decision-making aid for a company seeking to fulfil its ecological or sustainability responsibility in the entire production and supply chains.     

水生生物辐射剂量率计算在核电厂环境影响评价中的应用

生物辐射剂量率的计算是评价放射性元素对生物辐射影响的前提,也是核电厂环境影响报告书中不可缺少的组成部分。通过一个环境影响报告实例,介绍水生生物辐射剂量率的计算在核电厂环境影响评价中的应用。     

浅谈建设项目累积影响评价工作内容及方法

提出了我国进行建设项目累积影响评价的具体工作内容,包括:识别累积环境问题、确定评价范围、预测分析累积影响效应、累积影响结果评价、提出累积影响减缓措施、进行累积影响监测与适应性管理。并对适合于各个过程采用的分析评价方法作了归纳说明。     

生命周期评价新发展与工业应用

从国际生命周期小组的统计和国内外的案例,综述了新世纪生命周期评价（LCA）的发展和工业应用现状,对存在的问题进行探讨,就如何进一步改进提出建议。