农田氮素流失对环境的污染现状及防治对策

从地表水、地下水、大气以及农产品等方面 ,概述了农田氮素流失对环境的污染现状 ,阐述了控制农田氮素流失的防治对策 ,指出实施生态农业政策、优化氮肥管理、选育氮高效品种以及控释 /缓释肥料的应用将是今后农业生产发展的方向     

Croppers to livestock keepers: livelihood transitions to 2050 in Africa due to climate change

The impacts of climate change are expected to be generally detrimental for agriculture in many parts of Africa. Overall, warming and drying may reduce crop yields by 10–20% to 2050, but there are places where losses are likely to be much more severe. Increasing frequencies of heat stress, drought and flooding events will result in yet further deleterious effects on crop and livestock productivity. There will be places in the coming decades where the livelihood strategies of rural people may need to change, to preserve food security and provide income-generating options. These are likely to include areas of Africa that are already marginal for crop production; as these become increasingly marginal, then livestock may provide an alternative to cropping. We carried out some analysis to identify areas in sub-Saharan Africa where such transitions might occur. For the currently cropped areas (which already include the highland areas where cropping intensity may increase in the future), we estimated probabilities of failed seasons for current climate conditions, and compared these with estimates obtained for future climate conditions in 2050, using downscaled climate model output for a higher and a lower greenhouse-gas emission scenario. Transition zones can be identified where the increased probabilities of failed seasons may induce shifts from cropping to increased dependence on livestock. These zones are characterised in terms of existing agricultural system, current livestock densities, and levels of poverty. The analysis provides further evidence that climate change impacts in the marginal cropping lands may be severe, where poverty rates are already high. Results also suggest that those likely to be more affected are already more poor, on average. We discuss the implications of these results in a research-for-development targeting context that is likely to see the poor disproportionately and negatively affected by climate change.     

控制在用车排放恶化的有效措施

针对我国在用车排放比较严重的现状，我们认为：短期内易于实现，花费不高，不用对现有车辆作重大技术变动的有效措施是完善在用车Ｉ／Ｍ计划和进行在用国的加速淘汰工作。而且，对于用率和高污染车辆，完善的Ｉ／Ｍ计划也是更有效控制机动车排放污染所必需的。     

铅染毒导致小鼠DNA损伤与氧化损伤

为了研究亚急性铅暴露对小鼠的遗传毒性及氧化损伤的诱导,将不同剂量的醋酸铅对小鼠隔日灌胃4周,用彗星实验检测其外周血淋巴细胞DNA损伤,并测定肝组织中活性氧自由基(ROS)的水平和脂质过氧化主要终产物丙二醛(MDA)的含量.结果显示,随染铅剂量的增加,小鼠肝线粒体中的ROS水平明显升高,染铅剂量为500 mg·kg-1组与对照组相比有显著性差异;肝MDA含量以及淋巴细胞尾长和尾相显著增加,染铅剂量为50、100、500 mg·kg-1组与对照组相比均有显著性差异;MDA与尾长和尾相的变化趋势一致.诱导产生自由基并导致脂质过氧化作用增强及DNA损伤是铅引起机体损伤的主要机制之一.     

重庆市环境保护相关产业基本情况调查与发展对策建议

在重庆市环保相关产业调查的基础上，分析其发展中存在的主要问题，并针对问题提出具体的发展对策建议。     

Adapting to Climate Change in Africa

The intersection of present vulnerability and the prospect of climate change in Africa warrants proactive action now to reduce the risk of large-scale, adverse impacts. The process of planning adaptive strategies requires a systematic evaluation of priorities and constraints, and the involvement of stakeholders. An overview of climate change in Africa and case studies of impacts for agriculture and water underlie discussion of a typology of adaptive responses that may be most effective for different stakeholders. The most effective strategies are likely to be to reduce present vulnerability and to enhance a broad spectrum of capacity in responding to environmental, resource and economic perturbations. In some cases, such as design of water systems, an added risk factor should be considered.     

Contribution to advances in waste-to-energy technologies

This paper presents a number of recent advances in technologies and improvements in units for the thermal processing of municipal solid waste (MSW) and various other types of waste. The focus is on the ‘waste-to-energy’ approach; various criteria for this approach are discussed, as well as the inconsistent attitudes about waste management approaches that are present in various countries in the European Union. The presented achievements include low-NO_x burners, improved efficiency, heat exchangers, waste heat recovery systems, newly developed equipment for wet scrubbing, dioxin filters and systems for the treatment of sewage sludge.A new concept for a regional Waste-to-Energy Centre (WTEC) is outlined, the design of which is based on a combination of experience, know-how and a sophisticated approach. The proposed WTEC will use up-to-date technologies and will provide an adequate response to the growing population and rising standards of living as well to increasingly stringent environmental regulatory standards.Utilization of computational methods such as Computational Fluid Dynamics (CFD) for design optimisation and/or for troubleshooting is demonstrated with examples (flue gas duct, burner, combustion chamber). Several examples from industrial applications are summarized.     

中国如何进行生态城市建设

本文在概括论述生态城市的内涵、主要特征以及目前我国城市环境状况和生态环境建设初步兴起的基础上，重点针对我国国情论述了生态城市建设的指导思想、目标和对策，强调了改进城市规划和运行机制的重要性。     

情系阿拉善--召素套勒盖,一个西北乡村的故事

自地球存在以来,荒漠化就存在,只是现在人类毫无节制的生产方式、生活方式导致它进一步恶化。本刊通过展现阿拉善地区一个村庄所发生的故事,透示人类与荒漠化的关系,展现人与自然和谐相处的科学模式。     

台湾阳明山地景、保育与解说考察记

本文为台湾阳明山公园考察记述,重点叙述地景(地质遗迹)登录、评价与分区管理,地景与生态保育和解说服务的理念和实际管理、运作.从中可对建设国家地质公园,提高风景名胜区旅游的品位,实施寓教于游有所启示.     

起草《贵阳市建设循环经济城市条例》的基本考虑

本文从我国循环经济立法背景、循环经济立法在各国的发展状况、我国循环经济立法的必要性、循环经济立法的理论共性、循环经济地方立法的个性体现等五个方面阐述了起草我国第一部循环经济地方立法的基本思路。     

提升非政府组织参与国际气候治理能力的建议

中国在全球碳排放格局演化进程中的地位不断凸显,对于应对气候变化的认知和立场经历了从跟进、参与、贡献到引领的转变。中国在推进全球气候治理和国内碳达峰、碳中和目标实现的过程中,不仅政府要发挥作用,非政府组织也亟需发挥作用。当前国内气候变化相关的非政府组织在议题设置、话语把控、项目运作等方面的影响力较为有限。本文提出,可以从三个方面提升非政府组织参与国际气候治理的能力和水平：第一,与具有国际影响力的非政府组织合作,在其他国家开展气候治理行动;第二,充分发挥我国非政府组织在国外开展应对气候变化和生态环境保护合作行动的优势,提升合作效率;第三,在非政府组织的资金机制、管理制度等方面进行改革,助力其在国外更好地发挥作用,为非政府组织“走出去”充分赋能。     

Two methods to assess vulnerability to climate change in the Mexican agricultural sector

We applied two methods to assess vulnerability to climate change in Mexico’s agricultural sector. The first one was a principal component analysis (PCA) that weighted each variable separately. For the second one, we integrated the variables in a linear array in which all variables were weighted equally, and then, we used the arithmetic sum of the sub-indices of exposure and sensitivity minus the adaptive capacity to obtain the vulnerability index. We discuss the similarities and differences between two methods with respect to municipal-level maps as the outputs. The application of the method for the agricultural sector in Mexico gave us the spatial distribution of the high- and very-high vulnerability categories, which we propose as a tool for policy. The methods agreed that the very-high vulnerability category is present in 39 municipalities. Also we found that 16 % of the total population in the country is located in high-exposure areas. In addition, 41 % lives in municipalities identified as highly-sensitive. In terms of adaptive capacity, 20 % of the population lives in 1273 municipalities with low-adaptive capacity. Finally, we discuss the need for information regarding vulnerability at the national level to guide policies aimed at reducing exposure and sensitivity and increasing adaptive capacity.     

洱海鱼类多样性危机及解危对策

洱海原有土著鱼类17种,其中,有8种为洱海所特有。60年代以后土著鱼类逐渐减少,鱼类多样性出现危机。文章论述了50～90年代洱海鱼类的动态变化,分析了鱼类多样性危机的原因,并提出了解除洱海鱼类多样性危机的对策措施。      

Gaps in the capacity of modern forage crops to adapt to the changing climate in northern Europe

The within-species diversity in response to weather and the gaps in the response diversity in the modern set of forage crop cultivars were determined using an approach that assessed the adaptive capacity under global climate change. The annual dry matter (DM) yields were recorded in multi-location MTT (Maa- ja elintarviketalouden tutkimuskeskus) Agrifood Research Official Variety Trials in Finland for modern forage crop cultivars from 2000 to 2012, as a response to agroclimatic variables critical to yield based on the year-round weather data. The effect and interaction of cultivars and agroclimatic variables were analysed using mixed model. The relatively low adaptive capacity of timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis Huds.) indicates that diversification of the breeding material is warranted, particularly for resistance to high temperatures during primary growth and to high temperature sum 7 days after the first cut. All red clover cultivars (Trifolium pratense L.) suffered from both low and high accumulation of warm winter temperatures. Except for the red clover cultivars, cold stress during winter and lack of warm winter temperatures consistently reduced the yields of all species and cultivars. All tall fescue (Festuca arundinacea Schreb.) cultivars suffered from low precipitation during the fall hardening period. Although the set of festulolium (Festulolium pabulare) cultivars was also sensitive to low precipitation during the fall, festulolium was a good example of enhanced capacity to adapt to climate change with high response diversity because the cultivar germplasm base was diversified. Foreign origin in a cultivar pool was apparently not sufficient or necessary to ensure added value for a diversity of responses to climate change. Similar analyses to those used in this study, applied as practical tools for breeders, farmers and public actors, are important to secure the adaptive capacity of crops worldwide under global climate change.     

A multiple timescales approach to assess urgency in adaptation to climate change with an application to the tourism industry

As climate change adaptation is increasingly discussed and becoming a mainstream concept, different types of users are asking themselves if and when they should develop an adaptation strategy, often not knowing where to begin. Climate experts, on the other hand, have access to an enormous amount of data that could be useful to users but often do not know how to translate it into something practical. Both users and experts can be linked through two timescales, the system lifespan and climate vulnerability. While the system lifespan relies on the user’s estimation of his planning timeframe, the climate vulnerability is estimated from climate model projections and observations. We propose a simple tool to relate user and climate expert knowledge by combining the two timescales. To be reliable, the interconnection implies a dialogue to first identify what sensitive climate variable will impact the system and subsequently the extent of the impact. Climate data can then be used to identify, with the use of a simple graph, how sensitive a system is likely to be and help users position themselves about the urgency of adaptation. The concept has been successfully presented and applied to the tourism industry, notably the ski industry, which is showcased in this paper.     

NC-PC锚定微量Fe活化PMS降解水中2,4-二氯苯氧乙酸

采用分步热分解法制备了NC-PC（三维多孔碳材料）锚定的微量Fe基催化剂,用于活化过一硫酸盐（PMS）氧化降解水中2,4-二氯苯氧乙酸（2,4-D）.采用透射电子显微镜（TEM）、高精度比表面积仪（BET）、X射线光电子能谱分析（XPS）和电感耦合等离子体发射光谱分析（ICP）对催化剂进行表征.考察了不同金属、制备方法、催化剂投加量、PMS投加量、初始pH值以及水中不同阴离子（Cl^-、NO₃^-、HCO₃^-）对2,4-D降解的影响.结果表明,通过热分解法合成的Fe-NC-PC对2,4-D具有更好的降解效果,当2,4-D初始浓度为0.1mmol/L,初始pH=3.4,催化剂投加量0.15g/L,PMS浓度0.7mmol/L时,反应20min内2,4-D的去除率可达91%.随着催化剂投加量、PMS投加量的提高,2,4-D的降解效果提高;随着初始pH值的提高,2,4-D的降解效率逐渐降低;水中不同阴离子（Cl^-、NO₃^-、HCO₃^-）和腐殖酸（HA）对2,4-D的降解有轻微的抑制作用.通过自由基淬灭实验、EPR测试以及XPS分析了反应的主要活性物种和反应机理,发现材料制备过程中形成的Fe-N_x是主要的反应活性位,能够有效的活化PMS降解水中2,4-D,¹O₂在2,4-D的降解过程中起到主要作用.     

语文阅读教学如何利用主问题引领文本解读

在语文阅读教学中,教师的提问关系到整堂课的教学质量,关系到学生把握阅读的要领。"主问题"的提出,试图解决这样的问题。在教学实践中,从切入要害设计主问题、巧妙追问深化主问题两个方面来探究设计问题,优化课堂提问的策略,提高学生的语文素养。