聚合铝的形态稳定性及其动电特性的研究

本文采用改进的Ａｌ－Ｆｅｒｒｏｎ快速测定法研究了混凝过程中铝盐与聚合铝水解形态的转化规律及稳定性，并对混凝反应过程中铝与聚合铝溶解－沉淀形态分布与理论溶解度进行了对比，同时采用流动电流技术直接测定了铝盐与聚合铝絮凝剂的荷电状况，最后对发生在混凝过程中铝与聚合铝最佳凝聚形态进行了讨论。     

IsAmmophila arenaria (Marram grass) a threat to South African dune fields?

Ammophila arenaria (marram grass) was introduced to South Africa from Europe as a means of stabilizing the Cape Flats in the 1870s, but was only successfully established in the 1890s as it was found that seeds from the first introductions did not readily germinate. By the end of the last century, it was successfully used as a dune stabilizing grass. It is now widely used in stabilization projects along the Cape coastline, being established by planting cuttings or whole plants. Because of problems experienced of marram becoming invasive, especially on the west coast of North America, and the fact that we have many invasive species which threaten our indigenous dune fields, studies have been initiated on this plant in South Africa. Most work to date has involved investigating the methods used to establish the plant in stabilization sites, and very little has been done on the biology of the species in this country. Marram is generally thought not to seed in South Africa, and thus its spread has been limited. However, in the light of recent reports of successful germination of the seed, detailed studies on the phenology of seed production and establishment in natural areas will be undertaken. Studies on the natural control by fungal species and nematodes will be carried out in conjunction with work done in the Netherlands, so that a comparison of the biology of the species in South Africa can be made with that in Europe, where it is used extensively to stabilize dunes. Nomenclature: Arnold & de Wet (1993) for vascular plants.     

Plant species in arable field margins and road verges of central Norway

Plant species composition and species number were studied in two types of field margins: 31 arable field margins and 33 road verges. Both field margin types were adjacent to intensively managed grass or cereal fields. Effects of eight variables on field margin vegetation were studied. Despite having many plant species in common, composition and species number differed between the two field margin types, due to different ecological conditions and margin management. Arable field margins were composed of tall and/or nutrient demanding ubiquitous species and were characterised by species of later successional stages than those of road verges. The vegetation of road verges was lower and species numbers were higher than in arable field margins. The road verges contained several semi-natural meadow species that are declining in abundance. A CCA ordination of the field margins and the recorded variables showed that plant species composition was significantly affected by thickness of litter, slope, width, moisture level and type of crop in the adjacent field. Number of plant species was significantly higher in mown than unmown margins and generally higher in margins adjacent to fields with mainly grass production than in margins adjacent to fields with mainly cereal crops. In order to preserve botanical diversity in this agricultural landscape, the maintenance of regularly mown road verges should be prioritized.     

聚合氯化铝和改性聚合氯化铝中铝形态分布研究

利用Al-Ferron络合比色法研究实验室合成的聚合氯化铝和改性聚合氯化铝的铝形态分布,并对其合成工艺进行改进.聚合氯化铝合成条件为铝离子初始浓度为1 mol/L,物料比11,反应温度为60℃,熟化温度为60℃～65℃.合成改性聚合氯化铝适宜条件是Al/Si在0.7～1之间,聚硅酸聚合时间为90 min,模数为2的水玻璃.     

北京地区河流中大型底栖无脊椎动物与水质关系的研究

利用1983-1985年调查资料,对北京地区河流中大型底栖无脊椎动物群落结构用生态学方法进行评价。指示生物、Trent生物指数和Shannon种类多样性指数评价结果是一致的。     

羟基聚合氯化铝铁溶液的形态分布特征

采用改进的Ａｌ＝Ｆｅ－Ｆｅｒｒｏｎ逐时络合比色法定量研究了ＨＰＡＦＣ的形态分布，结合酸解聚实验和酸反一实验结果，综述了其形态分布特征，在碱化度Ｂ为１．０～２．０内，ｎＡｌ／ｎＦｅ＝９：１时，单体和二聚体（Ａｌ＋Ｆｅ）达２０％～６０％，ｎＡｌ／ｎＦｅ＝５：５时达３０％～５０％，ｎＡｌ／ｎＦｅ＝９：１时，中间多在络合物（Ａｌ／ｎＦｅ＝５：５时达５％～２０％，ｎＡｌ／ｎＦｅ＝９：１时，溶胶（Ａｌ＋Ｆｅ）     

高Al13纳米聚合氯化铝的结构表征及混凝效果

采用AlCl36H2O和Na2CO3制备了聚合氯化铝(PAC),并采用SO42-/Ba2+沉淀-置换法分离提纯了其中的纳米Al13形态,应用27Al-NMR和XRD等现代实验技术对其中的Al13形态进行了分析表征,27Al-NMR结果表明,分离提纯后样品中的Al13含量明显高于PAC,XRD结果表明,Al13的衍射峰出现在2q角为5~25之间;混凝烧杯实验表明,纳米级PAC较传统的混凝剂AlCl3、Al2(SO4)3和PAC具有更好的除浊、脱色效果.     

多氯联苯(PCBs)污染对秋茄Kandelia candel生长的影响

通过盆栽实验研究了不同浓度(180×10-9、900×10-9、1 800×10-9和2 700×10-9)的多氯联苯(PCBs)对红树植物秋茄Kandelia candel幼苗生长的影响.结果表明:秋茄的生长指标茎高、茎径、茎体积和生物量的生长量呈现先上升后下降的变化趋势,不过各处理的生长指标均高于对照组;研究表明,秋茄能在PCBs浓度为2 700×10-9的沉积物中正常生长,对PCBs有较强的耐受性和适应性.     

Carbon sequestration via afforestation as a sustainable action to mitigate climate change in Western Iran

Climate change involves increasing atmospheric carbon dioxide concentration which is driven by anthropogenic emissions. Afforestation, which is the establishment of forests on previously non‐forested lands, could be a suitable climate change mitigation strategy. The aim of this research is to evaluate the carbon sequestration capability of the Eucalyptus and Prosopis species in the Reza‐Abad afforestation park in western Iran. For this aim, three stands of any species were selected. For quantitative assessment, a transect was implemented at the length of 100 m. In trees located of transects, the general characteristics of species were measured. Also, for estimating the amount of litter, a sample plot has been measured at the center of the quadrate. These samples were taken from the afforested area, the control area inside the afforested area and another control area outside. In each stand, species were selected randomly and one‐eighth of the whole stand was taken for calculating the percentage of carbon and aerial biomass. Then the aboveground organs were weighted and after the transfer of different plant organs to the laboratory, the conversion factor of carbon sequestration of the plant organs was determined individually by combustion method. Also, soil samples were also collected from two depths of 0–15 and 15–30 cm in each of the cultivated and control parts. The results showed that there is a significant difference between the species and Prosopis has higher carbon sequestration than Eucalyptus. The carbon sequestration among different organs showed a significant difference, carbon sequestration was 19.24 t/ha for Eucalyptus and 18.43 t/ha for Prosopis. After an economic calculation, it was concluded that afforestation has a positive effect on the reduction of atmospheric carbon dioxide. Hence, these results allow decision makers to change land use from desert area to forest, and planting the Prosopis species is more recommendable than Eucalyptus for afforestation in such areas which are economically profitable.     

Company engagement with supply chains to protect biodiversity and rare,threatened, and endangered species

Future global megatrends project a population increase of 2 billion people between 2019 and 2050 and at least 1–2 billion people added to the global middle class between 2016 and 2030. In addition, 68% of the world's population is projected to be living in urban areas by 2050. With these projected large population increases and shifts, demand for food, water, and energy is projected to grow by approximately 35, 40, and 50%, respectively, between 2010 and 2030. In addition, between 1970 and 2014 there was an estimated 60% reduction in the number of wildlife in the world and an estimated net loss of 2.9 billion birds, or 29%, in North America between 1970 and 2018. Loss of species populations and number of species is interconnected with reduced health of biodiversity and ecosystems. Human activity has been the main catalyst for these substantial declines primarily through impacts on habitats. These losses are accelerating. Since a company's supply chain environmental impacts are often as great or greater than its own direct environmental impacts, it may be prudent for companies to engage with their supply chains to protect and enhance habitats and biodiversity and protect rare, threatened, and endangered species. As one example, companies may have opportunities and strategic reasons to include requirements in their supplier codes of conduct and supplier standards for suppliers to protect biodiversity and rare, threatened, and endangered species, as well as additional requirements to expand or enhance habitats and ecosystems to increase biodiversity. This article follows one pathway that companies could pursue further and with greater speed—to engage with their supply chains to strengthen supplier codes of conduct to protect biodiversity and rare, threatened, and endangered species. The importance of forests, private land, and landscape partnerships is discussed as means to protect much more of the planet's biodiversity and rare, threatened, and endangered species. Lastly, the article identifies examples of opportunities for companies to more formally incorporate biodiversity into their business, supply chain, and sustainability strategies.