网格状化合物模型II建立中的改进：H2O—CO2—CH4—N2—C2H6流体系统

以一切可利用的实验数据为基础的H20－CO2－CH4－N2－C2H6流体系统的网格状化合物稳定条件已建成为模型,对于包含在网格状化合物模型中的一些参数,如逸度气体在水中的溶解热度及热动力常数,可根据对它们最准确的计算结果估计纯净的CO2、CH4、N2、C2H6等气体水合物最适合的Kihara参数,对于CO2－CH4,CH4－C2H6等混合型气体水合物,引入过量吉布斯自由能函数并得到一个与实验数据非常吻合的结果,过量吉布斯自由能被描述为一个修正过的Margules方程,它取决于克分子量和温度。     

A population cartogram of New Zealand

The authors use 1981 census data to create a cartogram showing the counties of New Zealand in proportion to their population.     

Ecosystem management bioindicators: the ECOMAN project--a multi-biomarker approach to ecosystem management

The ECOMAN project was initiated from an awareness of the complexity of the functioning of coastal marine systems and the clear need for more pragmatic environmental assessment techniques linking environmental degradation with its causes. The aim of the project is to develop a suite of easy to use, cost effective and environmentally valid biological responses (biomarkers) to assess the general health of coastal systems, including estuaries. To achieve this aim, various sublethal endpoints are being measured and evaluated from a range of common coastal organisms showing different feeding types (filter feeding, grazing and predation) and habitat requirements (estuary and rocky shore) and at different levels of biological response (cellular, physiological and behavioural). This holistic integrated approach is essential to identify the full impact of chemical contamination on organisms, and enables the sensitivity of organisms to be ranked and key sentinel species for specific habitats to be identified.     

Evidence for enhanced bioavailability of trace elements in the marine ecosystem of Deception Island, a volcano in Antarctica

This study assessed whether trace elements present at Deception Island, an active submarine volcano in the Antarctic Peninsula, show enhanced biological availability to the local marine community. Using a weak acid extraction method to dissolve organic material and leach associated but not constitutive trace elements of sediments, fifteen elements were measured from seafloor sediment, seawater particulates, and tissues of benthic (bivalves, brittlestars, sea urchins) and pelagic (demersal and pelagic fishes, krill) organisms collected in the flooded caldera. The highest element concentrations were associated with seafloor sediment, the lowest with seawater particulates and organism tissues. In the case of Ag and Se, concentrations were highest in organism tissue, indicating contamination through the food chain and biomagnification of those elements. The elements Al, Fe, Mn, Sr, Ti, and to a lesser extent Zn, were the most concentrated of the trace elements for all sample types. This indicates that the whole ecosystem of Deception Island is contaminated with trace elements from local geothermal activity, which is also reflected in the pattern of element contamination in organisms. Accordingly, element concentrations were higher in organisms collected at Deception Island compared to those from the neighboring non-active volcanic King George Island, suggesting that volcanic activity enhances bioavailability of trace elements to marine organisms. Trace element concentrations were highest in digestive tissue of organisms, suggesting that elements at Deception Island are incorporated into the marine food web mainly through a dietary route.