The near-closure of a lagoon in western Iceland: how accurate were predictions of impacts on environment and biota?

The Environmental Impact Assessment (EIA) project instigated in connection with the near-closure of the large fjord-like lagoon Gilsfjörður in sub-arctic western Iceland with a road is described and discussed. Three phases were involved: a survey of pre-impact conditions of areas possibly affected as well as control areas, predictions of impacts of the road, and assessment of impacts up to 5–6 years after completion of the project. Emphasis was placed on birds and benthic flora and fauna. Although several predictions were upheld, others were not. The most unexpected changes were the elimination of kelp forest and some associated fauna inside the road as well as from large areas outside it. Feeding areas of the knot (Calidris canutus) and female eiders (Somateria mollissima) with ducklings also changed in unexpected ways. Unforeseen changes can partly be traced to inadequate knowledge of communities and their functioning in the area. The ecological requirements of many species involved, e.g. with respect to salinity, were imperfectly known. The predictions of engineers on the effects of the project on physical factors were not as accurate or detailed as desired. Some critical predictions of the engineers failed to make an impact on the ecologists, who then failed to predict some major changes in the biota, such as the disappearance of kelp forest outside the road. This study highlights some problems probably shared by many EIAs: (a) the near impossibility of finding suitable control areas, (b) the lack of ecological understanding of even common species, and possibly (c) inadequate communication between engineers and ecologists.     

The impact on tropospheric ozone formation on the implementation of a program for mobile emissions control: a case study in São Paulo,Brazil

The main sources of reactive hydrocarbons (RHC) and nitrogen oxides (NO_x), ozone precursors, in the Metropolitan Area of São Paulo (MASP) in the southeast of Brazil are emissions from vehicles fleets. Ambient surface ozone and particulate matter concentrations are air quality problem in the MASP. This study examined the impact that implementing a control program for mobile emissions has on ozone concentrations, An episode of high surface ozone concentrations occurring in the MASP during the March 13–15, 2000 period was used as a case study that was modeled for photochemical oxidants using the California Institute of Technology/Carnegie Mellon University three-dimensional photochemical model. Different scenarios were analyzed in relationship to the implementation of the Programa Nacional de Controle de Poluição por Veículos Automotores (PROCONVE, National Program to Control Motor Vehicle Pollution). Scenario 1 assumed that all vehicles were operating within PROCONVE guidelines. Scenarios 2 and 3 considered hypothetical situations in which the PROCONVE was not implemented. Scenario 2 set the premise that vehicles were using pre-1989 technology, whereas scenario 3 allowed for technological advances. A base case scenario, in which the official emission inventory for the year 2000 was employed, was also analyzed. The CIT model results show agreement with most measurements collected during 13–15 March 2000 modeling episode. Mean normalized bias for ozone, CO, RHC and NO _x are approximately 9.0, 6.0, ?8.3, 13.0%, respectively. Tropospheric ozone concentrations predicted for scenario 2 were higher than those predicted for scenarios 1, 3 and base case. This study makes a significant contribution to the evaluation of air quality improvement and provides data for use in evaluating the economic costs of implementing a program of motor vehicle pollution control aimed at protecting human health.     

基于GaN技术的大功率T/R组件可靠性设计与分析

结合T/R组件的工作原理,对影响大功率T/R组件可靠性的关键技术进行了设计与分析。通过与现有的基于GaAs技术的T/R组件设计电路对比分析,阐述了基于Ga N技术的大功率、高可靠性T/R组件的电路设计方法。     

电化学方法处理分散金黄HF-3R废水的研究

采用钛网作为阳极,钛网为阴极,对分散金黄HF-3R模拟染料废水进行了实验研究,探讨了电解时间、电解质种类及浓度、电流密度以及进水浓度对分散金黄HF-3R脱色效率的影响。结果表明:增加电流密度,提高电解质浓度,延长反应时间有利于分散金黄HF-3R色度的脱除,对于含有110 mg/L的分散金黄HF-3R溶液,电解质NaCl的质量浓度为20.0 g/L,电流密度为2.5 A/dm2,电解时间25 min,溶液的脱色率达到99%,COD去除率为98%。     

光催化/内电解协同处理分散蓝E-4R的研究

建立了微波无极紫外光催化氧化/内电解协同处理印染废水的新工艺。采用微波无极紫外光,以活性炭为光催化剂TiO2的载体,与外加铁屑构成内电解反应,处理分散蓝E-4R模拟废水。研究结果表明:协同工艺中主要是通过内电解过程产生的Fe3+捕获光电子来提高光催化作用的效率,而通过Fe2+催化H2O2形成光Fenton反应生成.OH的效应则较小。在曝气量为0.5 L/min、pH为5、铁屑投加量为40 g、染料初始浓度为50 mg/L时,分散蓝E-4R的脱色率和COD去除率分别达到99.56%、68.45%。     

厨房内空气污染危害及治理对策的探讨

本文对厨房内的主要空气污染源和污染因子进行了分析，探讨了厨房内空气污染状况及对人体健康的危害，提出了治理污染的可行性对策．     

Determining the tourism potential of the Altındere Valley National Park (Trabzon/Turkey) with respect to its conservation value

This study was conducted to determine the tourism potential of Alt?ndere Valley National Park with respect to its conservation and utilization. With its natural values, Alt?ndere Valley National Park is one of the internationally prominent areas of potential for the recreational and touristic facilities it offers.

A mathematical method – criterion referenced method – was applied within this study, which was done to portray the touristic potential (resulting from the touristic and recreational utilization of the national park area and recreational zone) of the national park, which was visited by an average of 200,000 local and foreign guests.

According to this method, the conservation and utilization values that appear on two opposite axes were examined in accordance with the natural resource values of the area, and conservation and utilization values for each criterion were determined. Depending on the data, the general exploitable touristic potential of the area was specified.

A survey study was conducted on groups from various disciplines and local & foreign tourists visiting the area in specifying the touristic potential of the National Park. Eleven criteria were defined concerning the area and a criterion reference was prepared for each criterion. Then, conservation and utilization values for each criterion and exploitable touristic potential were mathematically indicated. The fact that the attained values were reduced to a percentage basis provides the opportunity to compare the researched area to similar fields that use the same method. Within the scope of the method, several suggestions were made using the information obtained in the evaluation of the data for every other source value.     

北京秋季大气气溶胶光学厚度与Angstr?m指数观测研究

利用2010年10~11月CE318太阳光度计观测资料,得出了北京市秋季气溶胶光学厚度(AODλ=500nm),Angstr?m波长指数(α)和浑浊度(β).结果显示,气溶胶AOD,Angstr?m指数,浑浊度平均值分别为0.5(±0.69)、0.95(±0.33)、0.24(±0.31),变异系数分别为139%、35%和132%.非污染天,AOD变化较小,峰值出现在15:00,但大气中细粒子组分相对较高;污染天,AOD波动很大,没有明显的日变化,颗粒物以细粒子为主.非污染天,当α1.0,两者呈现正相关;污染天,两者无明显关系,但当AOD>1.0,α随AOD的增大而变小.当Vmax4m/s,AOD和α均出现小值,α与AOD呈负相关.风向也是影响α和AOD变化的重要因素,尤其ENE为主导风向时,α与AOD呈明显正相关.温度的变化并未对α和AOD的变化造成很大影响.局地扬尘或沙尘气溶胶呈非亲水性,但当α>0.5,AOD随相对湿度(RH)的增大有一定程度的增大.     

Willingness to pay for clean air in China

We use a residential sorting model incorporating migration disutility to recover the implicit value of clean air in China. The model is estimated using China Population Census Data along with PM2.5 satellite data. Our study provides new evidence on the willingness to pay for air quality improvements in developing countries and is the first application of an equilibrium sorting model to the valuation of non-market amenities in China. We employ two instrumental variables based on coal-fired electricity generation and wind direction to address the endogeneity of local air pollution. Results suggest important differences between the residential sorting model and a conventional hedonic model, highlighting the role of moving costs and the discreteness of the choice set. Our sorting results indicate that the economic value of air quality improvement associated with a one-unit decline in PM2.5 concentration is up to $8.83 billion for all Chinese households in 2005.