利用神经网络及数值模拟获取变压边力控制曲线

在应用Dynaform、Autoform等板料数值模拟软件的过程中 ,通常需要对压边力施力曲线进行各种预先的设定 ,但如何选定施力模式一直是一个比较棘手的问题 ,在文中利用数值模拟及MATLAB中的神经网络工具箱得出了压边力的最优控制曲线     

Optimising the environmental benefits of emission reductions from UK coal- and oil-fired power stations: a critical loads approach

This paper describes a method for determining reductions of SO₂ emissions from coal- and oil-fired power stations, oil refineries and large industrial units in the UK taking into account their pollution potential. The method is based on the use of two gridded data sets: critical loads, which represent the sensitivity of the environment to acid deposition and modelled estimates of total (wet + dry) sulphur deposition for 646 point sources within the UK. An iterative method is used to identify and subsequently reduce emissions from point sources that contribute most to areas of critical loads exceedance. This paper demonstrates how the method may be used to determine an optimal allocation of emissions across the UK which yields the maximum amount of environmental protection per unit of emission.The paper then goes on to consider the changes that will have to take place within the UK power generation industry in order to meet the revised EC Large Combustion Plant Directive which comes into force on 1 January 2008. Particular emphasis is placed upon proposed emissions trading schemes and the environmental implications of allowing trading between stations with high and low pollution potentials. The paper concludes by suggesting that the emissions trading process should take into account the pollution potential of each source, irrespective of whether the proposed emission is within the plant's agreed emission limit. An approach based entirely on minimizing environmental damage rather than one which takes cost into account, as in current integrated assessment modelling, could provide an interesting approach across the rest of Europe.     

大气微小颗粒物中汞的污染特性初步研究

采用分级采样器采集大气中微小颗粒物中的汞,用冷原子吸收测汞仪分析。结果表明,颗粒态汞浓度随粒径分布呈双峰型,2个峰值分别出现在粒径1.0μm和4.0μm左右,与水溶性离子,碳含量的粒径分布基本一致。PM_(1.6)、PM_(8)和TSP中颗粒态汞的浓度分别为0.150、0.273、0.429ng/m~3,汞的质量分数分别为3.75.1.09、1.07μg/g,高于背景参考值;结果还表明,颗粒态汞主要集中在细颗粒中。通过正态概率分布测算,PM_(1.6)、PM_(6)中汞主要来自于1个主体源;PM_(1.6)中汞的浓度与硫酸根离子呈显著性相关,而与硝酸根离子、氯离子则不显著相关:说明颗粒物中汞的主要来源可能与燃煤有关。     

聚电解质溶液中粘土颗粒的ζ电位

分别测定了 5种不同分子量和 5种不同分子链电荷密度的阴离子聚电解质高分子在钠蒙脱石粘土颗粒表面吸附前后粘粒的ζ电位 ;讨论分析了分子结构和体系环境对粘粒 ζ电位的影响以及聚电解质对粘土 -水分散体系的稳定作用。     

呼和浩特市空气污染潜势预报方法研究

利用1995～1997和2000年资料，统计分析了呼市边界层气象条件和影响呼市地区的天气系统，寻找出了城市污染与天气的关系，据此研究制定了有利和不利于污染物扩散的天气形势和气象要素指标，给出了不同污染物的空气质量等级判据，从而建立了呼市污染潜势预报方法。     

Total nitrogen and community turnover determine phosphorus use efficiency of phytoplankton along nutrient gradients in plateau lakes

Numerous studies support that biodiversity predict most to ecosystem functioning, but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied. We investigated 398 samples of the phytoplankton phosphorus resource use efficiency (RUE_P = chlorophyll-a concentration/dissolved phosphate) across two seasons in nine plateau lakes in Yunnan Province, China. We identified the main contributors to phytoplankton RUE_P and analyzed their potential influences on RUE_P at different lake trophic states. The results showed that total nitrogen (TN) contributed the most to RUE_P among the nine lakes, whereas community turnover (measured as community dissimilarity) explained the most to RUE_P variation across the two seasons. Moreover, TN also influenced RUE_P by affecting biodiversity. Species richness (SR), functional attribute diversity (FAD2), and dendrogram-based functional diversity (FDc) were positively correlated with RUE_P in both seasons, while evenness was negatively correlated with RUE_P at the end of the rainy season. We also found that the effects of biodiversity and turnover on RUE_P depended on the lake trophic states. SR and FAD2 were positively correlated with RUE_P in all three trophic states. Evenness showed a negative correlation with RUE_P at the eutrophic and oligotrophic levels, but a positive correlation at the mesotrophic level. Turnover had a negative influence on RUE_P at the eutrophic level, but a positive influence at the mesotrophic and oligotrophic levels. Overall, our results suggested that multiple factors and nutrient states need to be considered when the ecosystem functioning predictors and the biodiversity-ecosystem functioning relationships are investigated.     

城市供水管网漏损控制潜力研究

在我国各城市普遍缺水的同时，城市供水管网的漏损状况却相当的严重，科学衡量漏损控制的潜力，对于控制漏损和科学地进行城市水资源规划和需求管理非常重要。从技术潜力、经济潜力、社会潜力三方面将城市供水管网漏损控制的潜力进行了分析。提出了以社会最优值作为漏损控制的目标，以社会潜力作为需求管理的依据，同时综合考虑技术潜力和经济潜力。社会最优控制水平和企业的经济漏损控制水平之间有时会存在很大差异。科学的划分政府和企业在控制漏损的义务是非常必要的，如果需要企业的漏损控制水平小于经济漏损水平时政府应该给予一定的补偿，这样才能增加企业控制管网漏损的积极性。     

新疆玛纳斯河流域农业水资源可利用潜力分析

结合新疆玛纳斯河流域水文水资源、种植结构和节水技术发展等资料,从开源、节流两方面对流域近期(至2010年)、中远期(2010-2030年)农业水资源极限潜力、可挖掘潜力进行了估算。结果表明,就目前水资源的利用水平和开发趋势,玛纳斯河流域未来农业水资源的主要利用途径是开源与节流相结合,以节流为主。全流域尚有的农业灌溉水资源极限潜力为10.75×10⁸m³,近期农业水资源可挖掘潜力为2.13×10⁸m³,其中开源增水潜力0.40×10⁸m³,占18.8%,节流增水潜力1.73×10⁸m³,占81.2%;中远期农业水资源可挖掘潜力5.33×10⁸m³,其中开源增水潜力1.12×10⁸m³,占21.0%,节流增水潜力4.21×10⁸m³,占79.0%。该研究对区域制订节水灌溉规划及水资源系统优化配置具有重要参考价值。     

城市生活垃圾综合处理系统的选择

以上海城市生活垃圾处置为对象，利用层次分析方法，选择了分选回收＋堆肥＋卫生填埋的综合处置系统，并且确定了堆肥方式应首先考虑仓式静态好氧堆肥。经过运行费比较，所选择的综合处置系统比现行的处置系统具有明显的优势。     

酸碱度变化对日本三角涡虫生存及再生的影响

用自来水和去离子水配制不同的pH溶液，测定涡虫生存及再生的情况，以及涡虫可承受的pH变化幅度，确定日本三角涡虫对不同酸碱环境的耐受性。结果表明涡虫对酸碱环境的耐受力较强。