西藏“一江两河”中部流域农业生态环境及其保护途径

西藏“一江两河”中部流域地区是藏民族文化的发祥地,腹心地区。区内独特的生态环境、奇异的自然风光、丰富的自然资源,２１世纪将进入一个新的发展时期。但也存在诸多的生态环境等问题。本文从环境保护的角度出发,提出建设相对稳定人工生态系统,实现可持续发展的途径。      

温度、氨对鲢、鳙、草、鲤鱼的影响

为制定热排放标准的需要,用动态实验和静态实验方法研究了热冲击与氨对鲢、鳙、草、鲤鱼的急性和亚急性效应。结果表明：选择温度与起始致死温度（TL₅₀）值随着驯化温度的升高而增大,鳙鱼对热冲击的反应较敏感。氨对鲢、鳙、鲤鱼的急性毒性（96h）LC₅₀值分别为0.38、0.30、0.66mgNH₃/L（非离解氨）。水温升高5℃,鲤鱼的（96h）LC₅₀。值从0.66mgNH₃/L下降到0.44mgNH₃/L,热冲击明显提高了氨对鲤鱼的毒性。氨对鲤鱼的亚急性毒性结果表明,鳃、肝组织出现了病理改变。以上室内实验结果可作为评价监测热污染水质的科学依据。     

长江流域治理开发对生态与环境的改善和保护作用

长江流域治理开发是长江治理、开发、保护和管理的总称，包括流域治理、水资源开发利用、水资源保护、水土保持生态建设以及流域管理等内容，经过建国以来半个多世纪的发展和努力，长江流域治理开发取得了巨大的成就。在可持续发展战略和和谐社会思想的指导下，流域治理开发与生态环境建设息息相关，正确评价长江流域治理开发对生态与环境的改善和保护作用，对于促进治江事业的健康发展，充分发挥其生态环境效益具有十分重要的意义。通过对长江流域近五十多年来治理开发的总结归纳，分别从治理、开发、保护和管理等角度分析和总结了其对生态环境的保护和改善作用，认为长江流域治理开发总体上对生态、环境保护发挥了充分和积极的作用。     

生态县评价体系及持续发展战略的研究

在生态县规划研究中,以复合生态系统理论为指南,探讨了生态县的内涵和评价标体系,并确定了以生态农业为基础,以生态型工业为主导,以社会调控为保障,依靠科技进步,寓环境建设于经济社会发展之中的建设生态县的战略,在近年实践中初见成效。     

碳交易背景下中国华北地区碳代谢格局变化

碳排放权交易市场作为推进美丽中国建设、实现降碳减污绿色发展的重要手段,成为当前研究的热点问题.为探究碳交易背景下华北地区试点区域及非试点区域碳代谢过程,以城市碳代谢理论为依据,采取投入产出分析和生态网络分析相结合的研究方法.结果表明,北京和天津作为早期交易试点区域,区域从2012年后呈现直接碳排放量稳步下降、隐含碳排放量缓慢增加趋势.试点产业部门直接排放量与隐含排放量变化趋势一致,其中煤炭开采和洗选业、石油和天然气开采业和非金属矿物制品业减排效应明显,而排放量较高的电力、热力的生产和供应业表现为增加趋势.部门隐含碳排放强度与隐含碳排放量变化趋势相似证实部门隐含增加值在交易过程中并未增加.高碳排放部门的隐含碳排放量主要由长度小于6的代谢路径所贡献,因此应重点关注部门间较短路径传递的商品或服务的“清洁化”.在交易政策实施以前,区域产业部门间跨区域贸易较少,表现为低碳排放产品交换;2012年以后,随着京津冀城市群协同发展以及华北地区不断构筑的区域经济发展新格局,促使区域间跨区域和跨部门贸易增加.以碳排放权交易制度为背景,构建识别系统内关键参与者及关键路径的方法体系,可为区域性政策实施及可持续发展提供科学的发展建议.     

多驱动力作用下高层建筑火灾烟气输运规律研究现状

高层建筑发生火灾后,火灾烟气会在多种驱动力的作用下从着火房间迅速蔓延扩散至整栋建筑,严重威胁建筑内人员的生命安全。因此,控制建筑内烟气蔓延是建筑消防安全的一项重要内容。该文对热浮力、烟囱效应和室外风作用下建筑内火灾烟气输运规律进行分析,较系统地总结了这三种驱动力作用下火灾烟气输运的国内外研究成果,指出了以往研究的一些不足之处。根据国内外相关工作的研究进展及当前需要,对今后高层建筑火灾烟气输运规律的主要研究内容提出了几点展望。     

Identifying robust strategies for assisted migration in a competitive stochastic metacommunity

Assisted migration (AM) is the translocation of species beyond their historical range to locations that are expected to be more suitable under future climate change. However, a relocated population may fail to establish in its donor community if there is high uncertainty in decision-making, climate, and interactions with the recipient ecological community. To quantify the benefit to persistence and risk of establishment failure of AM under different management scenarios (e.g., choosing target species, proportion of population to relocate, and optimal location to relocate), we built a stochastic metacommunity model to simulate several species reproducing, dispersing, and competing on a temperature gradient as temperature increases over time. Without AM, the species were vulnerable to climate change when they had low population sizes, short dispersal, and strong poleward competition. When relocating species that exemplified these traits, AM increased the long-term persistence of the species most when relocating a fraction of the donor population, even if the remaining population was very small or rapidly declining. This suggests that leaving behind a fraction of the population could be a robust approach, allowing managers to repeat AM in case they move the species to the wrong place and at the wrong time, especially when it is difficult to identify a species’ optimal climate. We found that AM most benefitted species with low dispersal ability and least benefited species with narrow thermal tolerances, for which AM increased extinction risk on average. Although relocation did not affect the persistence of nontarget species in our simple competitive model, researchers will need to consider a more complete set of community interactions to comprehensively understand invasion potential.     

Cu/Cr co-stabilization mechanisms in a simulated Al2O3-Fe2O3-Cr2O3-CuO waste system

• Cu and Cr can be mostly incorporated into CuFe_xAl_yCr_2−x−yO₄ with a spinel structure. • Spinel phase is the most crucial structure for Cu and Cr co-stabilization. • Compared to Al, Fe and Cr are easier to be incorporated into the spinel structure. • ‘Waste-to-resource’ by thermal process at attainable temperatures can be achieved. Chromium slag usually contains various heavy metals, making its safe treatment difficult. Glass-ceramic sintering has been applied to resolve this issue and emerged as an effective method for metal immobilization by incorporating heavy metals into stable crystal structures. Currently, there is limited knowledge about the reaction pathways adopted by multiple heavy metals and the co-stabilization functions of the crystal structure. To study the Cu/Cr co-stabilization mechanisms during thermal treatment, a simulated system was prepared using a mixture with a molar ratio of Al₂O₃:Fe₂O₃:Cr₂O₃:CuO= 1:1:1:3. The samples were sintered at temperatures 600–1300°C followed by intensive analysis of phase constitutions and microstructure development. A spinel phase (CuFe_xAl_yCr_2−x−yO₄) started to generate at 700°C and the incorporation of Cu/Cr into the spinel largely complete at 900°C, although the spinel peak intensity continued increasing slightly at temperatures above 900°C. Fe₂O₃/Cr₂O₃ was more easily incorporated into the spinel at lower temperatures, while more Al₂O₃ was gradually incorporated into the spinel at higher temperatures. Additionally, sintered sample microstructures became more condensed and smoother with increased sintering temperature. Cu / Cr leachability substantially decreased after Cu/Cr incorporation into the spinel phase at elevated temperatures. At 600°C, the leached ratios for Cu and Cr were 6.28% and 0.65%, respectively. When sintering temperature was increased to 1300°C, the leached ratios for all metal components in the system were below 0.2%. This study proposes a sustainable method for managing Cu/Cr co-exist slag at reasonable temperatures.     

生态文明建设要点探索

生态文明是继工业文明之后更高层次的文明,而环境保护是生态文明建设的主要内容。在综合分析生态文明建设的目标、任务、本质、路径、关键和保障等理论问题的基础上,提出生态文明建设的要点:生态文明建设的目标是人与自然和谐,核心任务是生态环境保护,本质是发展方式的转变,关键是科技创新驱动,保障是制度建设。认为通过生态文明建设,可最终实现人类社会的可持续发展。