热固性耐高温环三磷腈基体树脂的合成及应用研究进展

对近年来国内外热固性环三磷腈耐高温基体树脂的研究进展及其在耐热、阻燃材料领域的应用进行简单综述。重点介绍了热固性环三磷腈衍生物的合成、结构和性能特点及其应用,并对国内外环三磷腈类阻燃、耐高温材料的研究进行了展望。     

Land classification used to select abandoned hazardous waste study sites

The biological effects of hazardous substances in the environment are influenced by climate, physiography, and biota. These factors interact to determine the transport and fate of chemicals, but are difficult to model accurately except for small areas with a large data base. The requirement for a large data base may be reduced locally if the regional influences of these factors were predetermined from existing data. Knowledge of the regional factors would also relax the restriction to considering only small areas. This paper advocates consideration of regional characteristics of the environment in the early stages of waste management strategy development. It presents as an example a procedure for selecting study sites from candidate-abandoned hazardous waste dumpsites in the southeastern United States. It uses small-scale maps of low resolution from the National Atlas to delineate the boundaries and to determine the environmental characteristics that prevail over units of land within the region. A computer map-overlay and graphic approach is used to facilitate the grouping of land types. Abandoned hazardous waste dumpsites found within land types that best represent the region are surveyed for selecting a study site. It is expected that environmental impact data obtained from a representative site would be useful for predicting impact potentials in similar remotely located areas within the same general region.     

西藏高原草地生态系统及其生态修复研究

文章在查阅相关文献的基础上,开展实地考察、咨询专家学者和有关管理部门,对西藏高原草地研究进行梳理归纳形成了4个时段;同时评析了不同调查结果的西藏草地面积,认为第二次西藏草原普查的8820.15×104 hm2比较符合现状;对西藏高原草地生态系统目前面临的最大问题—草地退化进行了探究,截至2012年,西藏天然草地退化面积达2355.54×104 hm2,占全区可利用草地面积的30.53%,其中草地退化以轻度退化为主;同时为更好地保护高寒特殊地区草地生态系统、确保其可持续发展,从现代生态修复学原理,提出几点生态修复技术措施的建议,为有关决策和研究提供参考。     

Setting Priorities for Research on Pollution Reduction Functions of Agricultural Buffers

The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it. Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest priority is given for work on the surface runoff filtration function, which is almost universally important to the amount of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation. Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments, may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions where buffer installation can substantially reduce stream pollution in these ways. Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation at local scales.     

Basic principles and ecological consequences of changing water regimes on nitrogen cycling in fluvial systems

Understanding the environmental consequences of changing water regimes is a daunting challenge for both resource managers and ecologists. Balancing human demands for fresh water with the needs of the environment for water in appropriate amounts and at the appropriate times are shaping the ways by which this natural resource will be used in the future. Based on past decisions that have rendered many freshwater resources unsuitable for use, we argue that river systems have a fundamental need for appropriate amounts and timing of water to maintain their biophysical integrity. Biophysical integrity is fundamental for the formulation of future sustainable management strategies. This article addresses three basic ecological principles driving the biogeochemical cycle of nitrogen in river systems. These are (1) how the mode of nitrogen delivery affects river ecosystem functioning, (2) how increasing contact between water and soil or sediment increases nitrogen retention and processing, and (3) the role of floods and droughts as important natural events that strongly influence pathways of nitrogen cycling in fluvial systems. New challenges related to the cumulative impact of water regime change, the scale of appraisal of these impacts, and the determination of the impacts due to natural and human changes are discussed. It is suggested that cost of long-term and long-distance cumulative impacts of hydrological changes should be evaluated against short-term economic benefits to determine the real environmental costs.     

Promotion of renewable energy technologies in Tanzania

The United Republic of Tanzania is currently facing energy problems that have seriously affected its socio-economic development and environment. To solve these problems, the country is striving to exploit its renewable energy potential, among other efforts. This publication highlights the prevailing energy situation in Tanzania and provides a short review of potential energy resources. It then discusses current institutional efforts and capabilities in research, development, diffusion and commercialization of renewable energy technologies. The paper also identifies some barriers to promotion of renewable energy technologies. Finally, it outlines the energy policy of Tanzania and actions taken by the government of Tanzania to promote renewable energy technologies.     

Toward quantifying water pollution abatement in response to installing buffers on crop land

The scientific research literature is reviewed (i) for evidence of how much reduction in nonpoint source pollution can be achieved by installing buffers on crop land, (ii) to summarize important factors that can affect this response, and (iii) to identify remaining major information gaps that limit our ability to make probable estimates. This review is intended to clarify the current scientific foundation of the USDA and similar buffer programs designed in part for water pollution abatement and to highlight important research needs. At this time, research reports are lacking that quantify a change in pollutant amounts (concentration and/or load) in streams or lakes in response to converting portions of cropped land to buffers. Most evidence that such a change should occur is indirect, coming from site-scale studies of individual functions of buffers that act to retain pollutants from runoff: (1) reduce surface runoff from fields, (2) filter surface runoff from fields, (3) filter groundwater runoff from fields, (4) reduce bank erosion, and (5) filter stream water. The term filter is used here to encompass the range of specific processes that act to reduce pollutant amounts in runoff flow. A consensus of experimental research on functions of buffers clearly shows that they can substantially limit sediment runoff from fields, retain sediment and sediment-bound pollutants from surface runoff, and remove nitrate N from groundwater runoff. Less certain is the magnitude of these functions compared to the cultivated crop condition that buffers would replace within the context of buffer installation programs. Other evidence suggests that buffer installation can substantially reduce bank erosion sources of sediment under certain circumstances. Studies have yet to address the degree to which buffer installation can enhance channel processes that remove pollutants from stream flow. Mathematical models offer an alternative way to develop estimates for water quality changes in response to buffer installation. Numerous site conditions and buffer design factors have been identified that can determine the magnitude of each buffer function. Accurate models must be able to account for and integrate these functions and factors over whole watersheds. At this time, only pollutant runoff and surface filtration functions have been modeled to this extent. Capability is increasing as research data is produced, models become more comprehensive, and new techniques provide means to describe variable conditions across watersheds. A great deal of professional judgment is still required to extrapolate current knowledge of buffer functions into broadly accurate estimates of water pollution abatement in response to buffer installation on crop land. Much important research remains to be done to improve this capability. The greatest need is to produce direct quantitative evidence of this response. Such data would confirm the hypothesis and enable direct testing of watershed-scale prediction models as they become available. Further study of individual pollution control functions is also needed, particularly to generate comparative evidence for how much they can be manipulated through buffer installation and management.     

Ecological Information System: Analyzing the Communication and Utilization of Scientific Information in Mexico

/ This study is concerned with the role that communication can play in facilitating the utilization of ecological information by different sectors of society involved in environmental decision-making. The ecological information system is used as a conceptual framework. This system is a model for the analysis of interactions between three sectors involved in the management of natural resources: researchers in ecology, change agents, and rural producers. Two case studies of organizations carrying out scientific research aimed at finding and implementing sustainable strategies of resource management were carried out. The purpose was to examine how real situations function in terms of communication strategies and to analyze such situations in relation to the model proposed. The analysis revealed the importance of promoting the feedback of information from change agents and rural producers to the research sector and the incorporation of this information into the research process. It also emphasized the relevance of having "active utilizer constituencies" within the rural producers who make demands upon the entire system in order to satisfy information needs. The creation of linkage systems facilitating the connection between the generation and utilization of information was supported. In particular, the establishment of special teams within research institutions is proposed, which could promote the links between the sectors through the use of communication as an instrument of work.     

胶州湾入海污染物目标总量控制研究

根据对胶州湾水质的实际调查结果,确定DIN,COD为胶州湾的主要污染因子。对胶州湾陆源污染物现状入海量进行调查,并以2008年为基准年,以COD,NH3-N为预测因子,预测2010年胶州湾各排污单元污染物增加情况。提出基于现实、分阶段实行目标总量控制的总量分配原则,根据国家和山东省给青岛市下达的总量控制指标和2008年青岛主要污染物实际排放情况,确定2010年胶州湾COD排放总量控制目标为34675t,NH3-N入海通量总量控制目标为6943t,并对各排污单元的排放总量控制目标值进行了分配。     

佛山市汾江河流域水污染物排放标准研究

随着汾江河综合整治的深入,现有排放标准已无法满足汾江河流域水体治理要求,迫切需要收紧汾江河流域排放标准。本论文简单介绍了汾江河流域基本情况,确定了标准制定原则及技术路线,分析了汾江河水环境和工业污染源现状,从而确定流域重点污染源和特征污染物。通过建立水流-水质模拟系统,计算汾江河主要污染因子水环境容量,并进行标准实施后的效益分析。