A Simulation of Temporal and Spatial Variations in Carbon at Landscape Level: A Case Study for Lake Abitibi Model Forest in Ontario,Canada

Using a case study of the Lake Abitibi Model Forest (LAMF), this study aims to assess the temporal and spatial variability in carbon storage during 1990–2000, and to present a comprehensive estimation of the carbon budget for LAMF's ecosystems. As well, it provided the information needed by local forest managers to develop ecological and carbon-based indicators and monitor the sustainability of forest ecosystems. Temporal and spatial carbon dynamics were simulated at the landscape level using ecosystem model TRIPLEX1.0 and Geographical Information System (GIS). The simulated net primary productivity (NPP) and carbon storage in forest biomass and soil were compared with field data and results from other studies for Canada's boreal forests. The results show that simulated NPP ranged from 3.26 to 3.34 tC ha⁻¹ yr⁻¹ in the 1990s and was consistent with the range measured during the Boreal Ecosystem-Atmosphere Studies (BOREAS) in central Canada. Modeled NPP was also compared with the estimation from remote sensing data. The density of total above-and belowground biomass was 125.3, 111.8, and 106.5 tC ha⁻¹ for black spruce, trembling aspen, and jack pine in the LAMF ecosystem, respectively. The total carbon density of forested land was estimated at 154.4 tC ha⁻¹ with the proportion of 4:6 for total biomass and soil. The analysis of net carbon balance of ecosystem suggested that the LAMF forest ecosystem was acting as a carbon sink with an allowable harvest in the 1990s.     

厌氧折流板反应器处理有毒废水及其污泥特性的研究

在１６．２Ｌ厌氧折流板反应器中，处理以葡萄糖为共基质的含五氯酚钠（ＰＣＰ－Ｎａ）有毒废水，进水ＣＯＤ为１１００－１２００ｍｇ／Ｌ，ＨＲＴ为１d。结果表明，ＡＢＲ 对有毒物负荷变化的适应能力强，当进水ＰＣＰ－Ｎa小于８ｍｇ／Ｌ时，出水ＣＯＤ在８０ｍｇ／Ｌ以下，ＰＣＰ－Ｎa在０．２ｍｇ／Ｌ以下，运行稳定。在有毒物低于抑制浓度 下反应器内参形成颗粒污泥，颗粒污泥表面为发酵产酸菌，内部为产甲烷菌，自身形成良好     

苯胺废水的超声波降解试验研究

采用多种频率和强度超声波对苯胺废水进行处理的实验表明 :其强度是影响处理效果的重要因素 ,再将超声与紫外、氧气联合进行动态处理 ,结果显示其降解效率大为提高 ,为此类废水实现工业化处理提供了高效、经济、无二次污染的方法     

Cells of the connective tissue differentiate and migrate into pollen sacs

In angiosperms, archesporial cells in the anther primordium undergo meiosis to form haploid pollen, the sole occupants of anther sacs. Anther sacs are held together by a matrix of parenchyma cells, the connective tissue. Cells of the connective tissue are not known to differentiate. We report the differentiation of parenchyma cells in the connective tissue of two Gordonia species into pollen-like structures (described as pseudopollen), which migrate into the anther sacs before dehiscence. Pollen and pseudopollen were distinguishable by morphology and staining. Pollen were tricolpate to spherical while pseudopollen were less rigid and transparent with a ribbed surface. Both types were different in size, shape, staining and surface architecture. The ratio of the number of pseudopollen to pollen was 1:3. During ontogeny in the connective tissue, neither cell division nor tetrad formation was observed and hence pseudopollen were presumed to be diploid. Only normal pollen germinated on a germination medium. Fixed preparations in time seemed to indicate that pseudopollen migrate from the connective tissue into the anther sac.     

Method of pollution sources assessment in relation to residential site selection

Much investigation supports a high incidence of disease and death rates when people live in ambient polluted air for a long time. Thus, the location of residential sites is important from a public health viewpoint. The method outlined in this paper is useful for determining the location of residential sites based on pollution sources assessment.     

Electrochemical study of sulfide solution in the presence of surfactants

Voltammetric curve studies on aqueous Na2S solution in the presence of three types of surfactants are presented. Presence of anodic surfactant (HTAB) in creases anode current density and makes the corresponding anode peak potential shift to more negative. Potentials of the reduction of elemental sulfur to intermediates Sx2-shift to more negative with the increasing of HTAB concentrations. In the presence of HTAB, the anode current density at 77oC increases more than at 34oC. The electrolysis indicates that anodic product sulfur loosely adhered to the graphite electrode surface when HTAB is added to the anolyte. The total efficiency of producing sulfur is high after several times of cycle electrolysis.The results show that anode passivation is minimized in the presence of HTAB. The depassivation effect of HTAB is discussed.     

海37引信回转体座冷挤压工艺

回转体座是海37引信中的关键件,要求有一定的机械强度、耐磨性.研制期间,曾用压铸铝合金,由于铝合金压铸内部存在着气孔,表面粗糙.不能满足其机械性能的要求.针对这一现象,研制了回转体座冷挤压成形工艺,零件表面质量好,成本低,满足了产品的机械性能要求.     

2,4-二氯苯氧乙酸完全抗原和抗体的制备

 以小分子环境污染物2,4-二氯苯氧乙酸(2,4-D)为半抗原,牛血清蛋白(BSA)为载体蛋白,通过与水溶性碳化二亚胺(EDC)的偶联反应,合成适当结合比、性能良好的2,4-D完全抗原,并制备了2,4-D的多克隆抗体.完全抗原合成方法为:在pH6、0.05mol/L的磷酸盐缓冲溶液中进行偶联反应,2,4-D的最终浓度控制为12mg/mL,于4℃条件下反应18h,EDC的加入量控制在6～9mg之间.以结合比为16:1的完全抗原免疫新西兰白兔,获得了效价达到6.55×106兔抗血清.抗血清稀释2000倍,剂量-反应曲线在2,4-D浓度为0.5～2000mg/L的范围内线性度最好,相关系数R=0.9946.抗血清稀释8000和16000倍,2,4-D的检测范围为8μg/L～125mg/L,线性相关系数R分别为0.9352和0.9655.经过免疫检测条件的优化,制备的抗血清可以用于饮用水中2,4-D的检测.     

加强城市灾害应急管理能力建设确保城市的可持续发展

本文通过对我国城市化与经济发展的关系,分析了我国城市面临的灾害形势及城市应急管理中存在的问题,提出了加强城市应急能力建设的途径,可供国内各大中城市参考和借鉴.