A Global Model Tracking Water, Nitrogen, and Land Inputs and Virtual Transfers from Industrialized Meat Production and Trade

Rising populations and incomes throughout the world have boosted meat demand by over 75% in the last 20years, intensifying pressures on production systems and the natural resources to which they are linked. As a growing proportion of global meat production is traded, the environmental impacts of production become increasingly separated from where the meat is consumed. In this paper, we quantify the use of three important resources associated with industrial livestock production and trade—water, land, and nitrogen—using a country-specific model that combines trade, agronomic, biogeochemical, and hydrological data. Our model focuses on pigs and chickens, as these animals are raised predominantly in intensive systems using concentrated, compound feeds. The results describe the geographical patterns of environmental resource use due to meat production, trade, and consumption. We show that US feed, animal, and meat destined for export require almost as much nitrogen and land, and 20% more water, than products destined for domestic consumption. Model results also demonstrate that among various production factors, improvements in crop yields and animal feed conversion efficiencies result in the most significant reductions in environmental harm. By explicitly tracking the externalities of meat production, we hope to bolster suppliers’ accountability and provide better information to meat consumers.

新疆矿区煤矿瓦斯排放现状与趋势分析

为获得新疆矿区当前生产规模对应的瓦斯排放基量,调查了研究矿区生产矿井的瓦斯排放现状.根据各矿区2004-2006年生产矿井的开采煤层、生产水平、生产规模和瓦斯排放等参数,对不同矿区和煤田进行了统计分析,计算了新疆矿区当前生产规模对应的瓦斯排放总量,同时对重点瓦斯防治矿区和一般瓦斯防治矿区进行了分类.调查结果表明,新疆矿区煤矿平均吨煤相对瓦斯涌出量由2004年的2.82m3/t增加到2006年的3.09 m3/t,呈逐年递增趋势; 新疆矿区2004-2006年的年平均瓦斯(CH4)排放量为1.05×108 m3/a;准南煤田(I)和塔北煤田(VI)的平均绝对瓦斯涌出量分别占全疆绝对瓦斯涌出总量的64.82%和15.19%,为相对瓦斯富集区,也是当前瓦斯防治的重点区域.按照矿区3年平均绝对瓦斯涌出量(大于1.00m3/min)或平均相对瓦斯涌出量(大于5m3/t)将新疆矿区分为重点瓦斯防治矿区和一般瓦斯防治矿区,并提出了瓦斯分类治理的具体建议.应用灰色系统理论,结合调查数据分别求解了新疆矿区原煤产量与绝对瓦斯涌出量的GM[1,1]预测模型.本研究为新疆煤炭资源后续规模开发过程中的相关环境决策和节能减排政策的实施提供了依据.     

“四沿”化工企业污水处理系统安全事故状态下负荷缓冲及安全环境(SE)联锁探讨

在对"四沿"(沿江、沿河、沿湖、沿海)化工行业污水处理方法及流程特点总结的基础上,归纳出应对水力和污染物冲击负荷的缓冲方法。为克服缓冲控制能力有限的缺点,提出一种新方法——SE(安全和环境)联锁,以期达到完善管理、提高控制效果的目的,并详细阐述了该方法在管理及技术层面的实施途径。     

细水雾中雾滴和高温环境的热质交换研究

由雾滴的表面的组分方程和能量方程入手,探讨雾滴在静止的高温环境中的热质交换及生存时间。应用折算薄膜理论,通过特征时间的比较,提出雾滴与高温环境主要通过沸腾机制实现热质交换;考虑滴径与速度变化的耦合作用,应用数值方法研究雾滴在强迫对流环境中与高温环境的热质交换情况。结果表明:对于滴径较小的雾滴不可能达到火焰区或可燃物表面实施火焰冷却和表面冷却,其灭火作用主要依赖于汽化吸热。     

20^#钢板镀铬在海洋环境条件下的腐蚀行为分析

本文根据20^#钢板镀铬材料在我国海洋环境的暴露结果,对20^#钢板镀铬材料在我国海洋环境条件下的腐蚀速度及腐蚀原因进行分析。     

家居室内设计及新进展的思考

在对传统室内设计基本观点阐述与理解的基础上分析其整体性、可持续发展,并着重探讨在物质文明和精神文明高度发展的今天,现代室内设计在个性化、自然性、现代性、艺术性等方面发展的新趋势.通过对现代室内设计特点和发展趋势的分析,创造出一个适合人们现代生活的理想空间.     

Relationships between street characteristics and perceived attractiveness for walking reported by elderly people

Walking is important for the health of elderly people. Previous studies have found a relationship between neighbourhood characteristics, physical activity and related health aspects. The multivariate linear regression model presented here describes the relationships between the perceived attractiveness of streets for walking along and (physical) street characteristics. Two hundred and eighty-eight independently living elderly people (between 55 and 80 years old) participated in the study. Street characteristics were assessed along homogeneous street subsections defined as ‘links’. Positively related to perceived attractiveness of links were the following street characteristics: slopes and/or stairs, zebra crossings, trees along the route, front gardens, bus and tram stops, shops, business buildings, catering establishments, passing through parks or the city centre, and traffic volume. Litter on the street, high-rise buildings, and neighbourhood density of dwellings were negatively related to perceived link attractiveness. Overall, the results suggest that three main aspects affect perceived attractiveness of streets for walking, namely tidiness of the street, its scenic value and the presence of activity or other people along the street. The results are discussed within the context of these three aspects.     

老庄道家思想所蕴含的生态伦理观念

中国古代思想家老子、庄子在生态环境伦理方面就如何协调人与自然的关系提出了许多宝贵的思想,如“天人合一”、“道法自然”、“知止”等。这些观点对我们解决二十一世纪所面临的生态环境问题具有重要的启迪意义。     

近十年生态工程在中国的进展

我国生态工程近 1 0多年有进一步发展 ,研究和应用对象扩展为社会 -经济 -自然复合生态系统 ,目标明确为可持续发展 ,从追求一维的经济增长或环境与自然保护 ,走向富裕、健康、文明三维一体的复合生态繁荣。在充实“整体、协调、循环、自生”的生态工程原理和生态控制论的基础上 ,总结出生态工程设计的 8项原则。方法论发展为从物理过程的量化走向生态过程的序化 ,从工程结构的优化走向生态格局的进化 ,从机器的人工智能走向人的生态智能。技术路线发展了硬件、软件、心件耦合 ;多学科、多技术的系统组合 ;调控复合生态系统全生态过程 ;寓环境保护于生产和消费中 ,寓废弃物处理于利用中 ;结构和功能纵横耦合成食物链网式、生命周期式、生态系统式等网络结构     

山西省湿地的基本特征及保护

论述了山西省湿地的基本环境特征 ,指出了存在的问题 ,并提出了山西省湿地生态系统保护利用的科学对策