有机质对p,p′-DDE在土壤中的吸附影响

为研究有机质对p, p′-DDE在土壤中的吸附影响因素,采用批量试验方法,分析p, p′-DDE在包气带土壤及含水层土壤上吸附量的变化及有机质对p, p′-DDE在土壤中的吸附影响.结果表明,p, p′-DDE在土壤中的吸附均符合先快后慢、最后达到吸附平衡的规律;其吸附动力学曲线用一级和二级反应动力学方程均能较好拟合,说明p, p′-DDE在这两种物质中的吸附以简单吸附为主,同时包含表面吸附、颗粒内部扩散等过程.包气带土壤和含水层土壤等温吸附线的拟合相关系数(R2)均大于0.95,符合Freundlich模型和线性模型,而含水层样品与Freundlich模型拟合得更好,表明p, p′-DDE在包气带土壤中的吸附以单分子层吸附为主,而在含水层土壤中的吸附还伴随着多分子层吸附的复杂过程;去除内源DOM(溶解性有机质)后,样品对p, p′-DDE的吸附量呈增加趋势,按吸附增加量由小到大的排序为1-1(0~10 cm) < 1-2(120~150 cm) < 2-4(100~120 cm),说明内源DOM的存在总体上抑制了p, p′-DDE的吸附,并且w(DOM)越高,其抑制作用越强;外源DOM的加入抑制了土壤对p, p′-DDE的吸附;去除有机质后样品对p, p′-DDE的吸附量与w(黏土矿物)具有正相关性.研究显示,有机质对土壤中有机污染物的吸附迁移研究对土壤修复有重要意义,需要对有机质影响土壤的吸附机制进行更深层次的研究.      

Article 3.3 and 3.4 of the Kyoto Protocol: consequences for industrialised countries’ commitment,the monitoring needs,and possible side effects

In the Kyoto Protocol, industrialised countries have agreed to reduce their carbon dioxide emissions. To achieve that target, direct human induced activities initiated in the Land-use Change and Forestry sector since 1990, shall be included. However, the wording in the Protocol has caused confusion. The IPCC has been requested to deliver a Special Report on Land-use, Land-use Change and Forestry issues arising from this Protocol. In the present study a limited initial assessment of the implications of alternative interpretations of Afforestation, Reforestation and Deforestation (ARD), addition of the soils compartment, the selection of additional activities, and feasibility of monitoring was done for a limited number of countries.The results show that it is possible to keep the biosphere articles in the Protocol even though we had to make several assumptions concerning for example, areas of application and effectiveness of additional activities. The consequences of alternative interpretations for ARD have a large impact on the countries’ assigned amount; varying from a compensation of 26% of total national emissions (Forestry interpretation for Sweden) to an addition of an extra 13% of the emissions (Global interpretation for Australia). Through selection of a large set of additional activities, most of the studied industrialised countries achieve more sequestration than the reduction of emissions they have committed themselves to. Methods for monitoring are available, but there is no one ideal method. Depending on scale and site: a combination of forest inventory with flux measurements and remote sensing is proposed.     

高温液晶N,N′-双[对苯基苄叉]α,α′-双对甲苯胺(简称BPhBT)的合成和测定多环芳烃某些色谱性能评价

1890年,O.Lehmannt为了描述固态晶体和流动体的介晶态而首先提出了“液晶”这一概念。目前,已知有几千种有机物当加热其晶态超过熔点时会形成液晶。液晶就是指这样一类物质:它在一定温度范围内既具有液体的流动性和连续性又具有晶体的各向异性,它是一类有序流体。     

Radiometric studies of clear air attenuation and atmospheric water vapour at 22.235 GHz over calcutta (lat. 22°32′N,long. 88°20′E)

22.235 GHz is the thermal emission line of water vapour in the atmosphere. An estimate of attenuation and hence the water vapour content in the atmosphere has been made by using a 22.235 GHz radiometer installed at the Institute of Radiophysics and Electronics, Calcutta. The experimental results are compared with the results obtained by another 22.235 GHz radiometer over Delhi. The results are discussed and compared in the light of radiosonde observations over Calcutta. The results show a good resemblance between the radiosonde and radiometric observations.