浮萍生长及其除磷效率的影响因素的研究

磷是藻类增殖的限制因子,是引起水体富营养化的关键营养物质.有效除磷,能在很大程度上减轻水体的富营养化.利用浮萍科植物吸收转化污水中的营养物质引起了越来越多研究者的关注,但对浮萍科植物除磷效果的影响因素的研究相对较少.以少根紫萍(Spirodela oligorrhiza)为供试材料,以完全培养液为处理对象,研究了培养液pH、少根紫萍初始放养密度对其生长及除磷效率的影响.结果表明:少根紫萍能够耐受的最低pH在4左右,在pH＝5～9能正常生长,在pH＝6～8具有较高的TP去除率,最高去除率可达84.1%;少根紫萍的相对增长率随其初始放养密度的增加而降低,但其鲜重增长量、平均增长速率、TP去除率及平均TP去除速率均随着初始放养密度的增加而增加.     

生存空间相对性的再研究

生存空间可分为狭义和广义两种,狭义生存空间的特点是有限性和潜在性,扩展性或相对性则是广义生存空间的最大特征;对生存空间的分类研究,有助于某一国家或地区生存现状和发展潜力的评价;人们通过贸易,交换着各自的生存空间;发展经济和科学技术,合理分配生活和生产空间,保护环境,控制人口,以及对资源的合理分配,是人类保护和扩大生存空间努力的基本方面。     

黄土高原半干旱区侧柏林群落土壤呼吸日变化及季节动态变化特征

Desertification is one of the most serious eco-environmental problems around Qinghai Lake. Based on GIS and RS, GIS analysis was used to obtain the information of spatial-temporal change and different pattern of desertification in each county around Qinghai Lake in four phases of 1976, 1987, 1995 and 2006. Using the function of intersect and overlay supported by ARCGIS, with analyzing attributes of vector RS images, we obtained transition data and established transfer matrix of land-use types in recent 30 years, besides, protracted land-use transition maps of all desertification classes. In further, we analyzed transition quantity and direction of desertification in each county, moreover, reconstructed the process of spatial-temporal evolution of desertification. The results are showed below: (1) it′s the transition between desertified land and others but not in the desertified that played the main role in Gangcha and Gonghe County, while the transfer between desertified lands were greater than that with other land-use types in Haiyan County. (2) Extremely severe desertified land mainly distributes in Ketu and Sand Islands that belongs to Haiyan County, and moderate desertified land in riversides of Gangcha County, also, the light desertification expanded too rapidly to become the most desertified land-use type in the surrounding of Qinghai Lake since 1976. (3) By using relative change rate of desertified land, the regional variability rank from top to toe was Gangcha, Haiyan and Gonghe.     

对我院英语分级教学的进一步探索

我校从2005年开始在大一年级试实施分级教学，一个学期的教学实践证明我们的改革是可行的，我们的分级教学取得了初步的效果。     

安徽省农民人均纯收入地域差异及其原因分析

以SPSS V13．0、Excel、Eviews 3．1和ArcView GIS3．2为工具，运用层次聚类分析和相关分析等方法，分析了安徽省农民人均纯收入的地域差异以及引起地域差异的原因。结果表明，安徽省农民人均纯收入的地域分异由东南向西北递减，并与经济发展水平区内分异性相吻合，这种差异是由自然条件差异和社会条件差异共同造成的。本研究对安徽省农村区域发展均衡性具有一定的指导意义。     

Contamination by Cd, Cu, Pb, and Zn in mine wastes from abandoned metal mines classified as mineralization types in Korea

The objective of this study was to investigate heavy metal contamination and geochemical characteristics of mine wastes, including tailings, from 38 abandoned mines classified as five mineralization types. Mine waste materials including tailings and soils were sampled from the mines and the physical and chemical characteristics of the samples were analyzed. The particle size of tailings was in the range of 10–100 μm. The pH of the waste covered a wide range, from 1.73 to 8.11, and was influenced by associated minerals and elevated levels of Cd, Cu, Pb, and Zn, extracted by a Korean Standard Method (digestion with 0.1 mol L⁻¹ HCl), which were found in the wastes. Half of the samples contained heavy metals at levels above those stipulated by the Soil Environmental Conservation Act (SECA) in Korea. In addition, extremely high concentrations of the metals were also found in mine wastes extracted by aqua regia, especially those from mines associated with sulfide minerals. Thus, it can be expected that trace elements in mine wastes may be dispersed both downstream and downslope through water and wind. Eventually they may pose a potential health risk to residents in the vicinity of the mine. It is necessary to control mine wastes by using a proper method for their reclamation, such as neutralization of the mine wastes using a fine-grained limestone.     

Predicting Extinction Risk of Brazilian Atlantic Forest Angiosperms

Understanding how plant life history affects species vulnerability to anthropogenic disturbances and environmental change is a major ecological challenge. We examined how vegetation type, growth form, and geographic range size relate to extinction risk throughout the Brazilian Atlantic Forest domain. We used a database containing species‐level information of 6,929 angiosperms within 112 families and a molecular‐based working phylogeny. We used decision trees, standard regression, and phylogenetic regression to explore the relationships between species attributes and extinction risk. We found a significant phylogenetic signal in extinction risk. Vegetation type, growth form, and geographic range size were related to species extinction risk, but the effect of growth form was not evident after phylogeny was controlled for. Species restricted to either rocky outcrops or scrub vegetation on sandy coastal plains exhibited the highest extinction risk among vegetation types, a finding that supports the hypothesis that species adapted to resource‐limited environments are more vulnerable to extinction. Among growth forms, epiphytes were associated with the highest extinction risk in non‐phylogenetic regression models, followed by trees, whereas shrubs and climbers were associated with lower extinction risk. However, the higher extinction risk of epiphytes was not significant after correcting for phylogenetic relatedness. Our findings provide new indicators of extinction risk and insights into the mechanisms governing plant vulnerability to extinction in a highly diverse flora where human disturbances are both frequent and widespread. Predicción del Riesgo de Extinción de Angiospermas del Bosque Atlántico Brasileño     

长江山区航道剖面能见度分析及局地影响因素初探

为了分析三峡航道不同区域能见度基本特征,比较不同垂直剖面、沿江距离对局地能见度的影响,基于中国气象局沿江、剖面布设的12个能见度监测点近3 a观测资料,对比分析了三峡航道涪陵、万州、宜昌3组区域12个监测点的能见度时空分布特征,并对能见度的局地差异做了初步讨论。结果表明：涪陵区雾情对航运安全影响最大,万州和宜昌区其次。涪陵区和万州区雾日的月际变化趋势一致,5、6月和11、12月为大雾高发时期。不同剖面能见度的日变化分析表明早晨至上午时间为大雾高发时段,午后至傍晚前为大雾低发时段。通过能见度与局地因子的关系模型验证,三峡航道能见度局地差异大部分源于监测点的海拔高度及可能的水体影响等,同组区域内,高海拔点、临近水域点平均能见度明显偏低,雾情频次也相对较高     

湖北省主要植烟区土壤肥力状况及分析

2005年以来测土配方施肥项目获取了大量土壤数据,通过对湖北省2009和2010年所获取的植烟区土壤养分数据进行抽样分析,并划分以十堰为核心的环神农架、以恩施为核心的鄂西南、神农架及以襄阳、宜昌为核心的鄂西北4个烟区,分别探讨不同烟区、不同土壤类型植烟土壤养分丰缺状况。结果表明,目前湖北省烟区土壤pH值、有机质、碱解氮、有效磷和速效钾含量分别为62、233 g/kg、1097 mg/kg、195 mg/kg和1236 mg/kg;569%的土壤pH适宜烟草生长,617%的土壤有机质含量在15～35 g/kg,土壤碱解氮、有效磷和速效钾缺乏面积分别为481%、363%和574%;各养分元素在不同烟区的分布存在一定差异,土壤pH以鄂西南最低,有机质含量鄂西南及神农架烟区明显高于环神农架和鄂西北地区,土壤碱解氮、有效磷含量鄂西南明显高于其余3个烟区,而土壤速效钾含量又以鄂西南烟区最低;湖北省烟区90%以上土壤为黄棕壤、水稻土、黄壤、石灰土、紫色土和棕壤,其中棕壤肥力水平较高,紫色土有机质及碱解氮含量低,水稻土有效磷和速效钾含量低。本研究还说明,充分利用测土配方施肥项目的资料对土壤养分数据进行系统分析,可全面掌握区域性土壤肥力现状并能指导科学施肥     

京杭运河常州段氮形态的时空分布特征研究

对京杭运河常州段8个研究点位水体中的氮形态（TN、NH4＋-N、NO2--N和NO3--N）和环境因子（pH、T和DO）进行了连续9个月的动态监测,全面研究了各氮形态的随时间和空间的动态变化规律,并对各氮形态及环境因子进行了相关性分析。常州段水体月平均NH4＋-N变化范围为（0.589±0.351）～（3.148±1.178）mg.L-1,TN变化范围为（3.373±1.379）～（7.373±2.307）mg.L-1,枯水期到丰水期各氮形态整体表现出波动性下降趋势,其中出境断面NH4＋-N下降趋势平稳,NO3--N则是主导出境断面TN含量的主要形态。各点位NH4＋-N的平均浓度范围为（1.202±0.492）～（2.813±1.566）mg.L-1,TN范围为（3.520±0.504）～（8.349±3.679）mg.L-1,各形态氮含量基本呈现出上游段（S）〈新运河（G）〈老运河（L）〈下游（X）的空间分布特征,其中下游段存在一个重要的氮素上升突变段,NO3--N是对TN的贡献率（43.8%～57.4%）最大的无机态氮,其次是NH4＋-N、ON、NO2--N,其中有机氮对TN的贡献率（13.3%）则以老河段最高。NH4＋-N和NO3--N、TN、pH相关系数分别为0.397＊＊、0.932＊＊、0.261＊,与DO相关系数为-0.344＊＊,陆源输入及DO不足是京杭运河常州段氮污染严重的重要原因。