浅谈姜堰市溱湖湿地生态保护与对策研究

近年来,姜堰市日益加剧的人类活动和资源开发,影响了溱湖湿地的生态保护。在分析溱湖湿地资源现状的基础上,指出存在的问题,并提出相应的对策建议。     

Aggregation and ecotoxicity of CeO₂ nanoparticles in synthetic and natural waters with variable pH, organic matter concentration and ionic strength

The influence of pH (6.0-9.0), natural organic matter (NOM) (0-10 mg C/L) and ionic strength (IS) (1.7-40 mM) on 14 nm CeO₂ NP aggregation and ecotoxicity towards the alga Pseudokirchneriella subcapitata was assessed following a central composite design. Mean NP aggregate sizes ranged between 200 and 10000 nm. Increasing pH and IS enhanced aggregation, while increasing NOM decreased mean aggregate sizes. The 48 h-E_rC20s ranged between 4.7 and 395.8 mg CeO₂/L. An equation for predicting the 48 h-E_rC20 (48 h-E_rC20 = −1626.4 × (pH) + 109.45 × (pH)² + 116.49 × ([NOM]) − 14.317 × (pH) × ([NOM]) + 6007.2) was developed. In a validation study with natural waters the predicted 48 h-E_rC20 was a factor 1.08-2.57 lower compared to the experimental values.     

鄱阳湖典型苔草湿地生物量季节变化及固碳功能评价

为进一步评估鄱阳湖湿地碳平衡,量化湿地固碳功能,于2009年9月～2011年5月,在鄱阳湖南矶湿地国家级自然保护区,选择以灰化苔草为建群种的洲滩湿地,采取收获法测定了灰化苔草4个生长季的地上、地下生物量及净初级生产力(NPP)。结果表明：1）苔草地上、地下生物量均具有明显的季节变化模式,变化范围分别为14608～1 77067 、1 80627～4 03256 g/m2;地下生物量与地上生物量的比例变化范围为208～1744,平均值为519。2）苔草地上地下生物量、NPP均表现为春季高于秋季。3）受洲滩淹水时间影响,苔草生物量、NPP具有显著的年际差异, 2010～2011年度苔草NPP仅相当于2009～2010年度的625%;NPP的下降地上部分较地下部分更明显。4）鄱阳湖湿地苔草固碳潜力巨大,2个年度固碳量分别为1 92383,1 23121 gC/m2     

雅砻江流域湿地景观格局变化分析

应用ArcGIS软件,对雅砻江流域湿地1986和2000年遥感数据进行解译、矢量化处理,用Apack软件进行湿地景观格局指数计算,研究了近15 a雅砻江流域景观空间格局特征及其变化。结果表明：（1）近15 a雅砻江流域湿地景观面积减少,减少量为49404 hm2,占2000年湿地总面积的0506%;（2）两个时期内湿地斑块密度保持不变,湿地景观的聚集度都很高,均在099以上,湿地景观集中分布,破碎化水平低;（3）雅砻江流域湿地景观的多样性指数水平和均匀度水平较低,而且两指数在两个个时期内没有发生太大的变化,且各类湿地景观比例差异相对较大,沼泽湿地景观控制的程度较高;（4）雅砻江流域的5类湿地景观分布质心基本上未发生变化,但总体格局分布质心向南偏移001°,再向西偏移023°,整体上向西南方向偏移了2532 km     

Technologically enhanced 210Pb and 210Po in iron and steel industry

Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the ²¹⁰Pb and ²¹⁰Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of ²¹⁰Pb and ²¹⁰Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of ²¹⁰Pb and ²¹⁰Po in the range of <DL-4238 and 1-5660 Bq/kg, respectively, were found. According to the assumed scenarios, the occupational exposures by inhalation are much lower than the recommended annual effective dose limit, although the environmental impact due to waste storage and/or use should be considered based on case by case evaluation.     

Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities

In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 × 10⁻⁵ mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures.     

喀纳斯自然保护区生态系统服务价值变化研究

生态系统可持续发展是随着全球范围内可持续发展研究的深入和人们对环境破坏和资源利用认识的不断加深而逐渐形成的.人类社会的可持续发展从根本上取决于生态系统及其服务的可持续性,本文应用喀纳斯自然保护区1980、2005年两期Landsat TM影像解译数据,参照谢高地等制定的中国生态系统单位面积生态服务当量因子和新疆布尔津县单位面积农田生态系统提供的食物生产服务的经济价值,确定喀纳斯自然保护区生态系统单位面积生态服务价值系数,对保护区生态系统服务价值及其变化进行了估算和比较.结果表明,林地和草地是喀纳斯自然保护区主要的土地利用类型,25年间土地利用总体上发生了明显变化,林地面积在减少,革地、水域、建设用地面积略有增加;保护区生态系统服务价值由1980年的37.289亿元减少至2005年的36.351亿元,有林地和离覆盖度草地的减少是服务价值降低的主要原因;主要由林地、草地和水域提供的维持生物多样性、水文调节、气候调节、保持土壤等单项功能服务价值均呈现不同程度地减少,说明保护区生态系统结构和功能已受到影响,保护区生态环境质量不断趋向退化.     

An Investigation of Flashing-Driven Natural Circulation

Natural circulation driven boiling systems are extensively used for passive heat removal, such as in nuclear power plants. The flashing phenomenon and the associated flow instabilities in a natural circulation loop are reported here. An experimental facility is constructed with a heater, an adiabatic riser, a condenser and an adiabatic down comer to study the instability regions. The experimental geometry is modeled using RELAP5. At high power (i.e., at 6 kW) flashing instability is observed when the inlet sub cooling is within the range of 7° C to 12° C. It is also found that the presence of an inlet restriction does not help to suppress the flashing induced flow oscillation. A good comparison between the experimental and numerical results is observed and this loop can be used for validation exercises of commercial codes.     

Planning and design of Berg-en-Dal,a new camp in Kruger National Park

The premise of this article is that the planning and design of new rest camps in conservation areas should be based on ecological principles in such a way that the plant ecology within the camp be an integral part and extension of the natural ecology of its immediate vicinity. This is desirable so that visitors to the camp will be provided not only with facilities for resting, eating, and sleeping, but also be able to enjoy and study the natural environment in a relaxed atmosphere. The Berg-en-Dal rest camp, which was established in Kruger National Park, was planned in such a way and designed according to the principles outlined by the authors in a companion article. The planning included six zones: a control zone, day visitor zone, overnight visitor zone, staff accommodation zone, recreation zone, and service zone. The point is stressed that plant species selected to be used as additional vegetation to those already growing in the camp were endemic to the nine landscape facets identified in the camp. The design allowed for separation of the various land-use zones in such a way that they would complement each other rather than be a hindrance to each other. The camp has been built according to the plans included in this article and has proved to be a great success. The conclusion is drawn that the planning principles are sound and should be used in the future for the planning and design of rest camps for conservation areas in South Africa.     

REMOVAL OF FLOODWATER SEDIMENTS BY A CLEARCUT TUPELO-CYPRESS WETLAND1

ABSTRACT: A palustrine water tupelo (Nyssa aquatica L.)-baldcy-press (Taxodium distichum (L.) Rich.) swamp in southwestern Alabama was subjected to three types of disturbance, including helicopter logging, rubber-tired skidder logging simulation, and helicopter logging followed by an herbicide application. An adjacent undisturbed stand served as a control area. Post-harvest collection of sedimentation data revealed that the herbaceous and woody vegetation regrowth within the helicopter and skidded clearcut areas trapped more sediments than did the control or herbicide treatment areas. Clearcutting, followed by plant regrowth, improved the wet-land's capacity to remove sediments from overbank flow flood waters.