高美古全夜视宁度的变化

介绍了云南丽江高美古天文候选点,１９９５年１２月～１９９６年１１月全夜视宁度观测结果,全年平均ｒ０＝１６．５０ｃｍ（ＦＷＨＭ＝０．６７″）夜平均极大值ｒｍａｘ＝２２．４１ｃｍ（０．４９″夜平均极小值ｒｍｉｎ＝１２９５ｃｍ（０．８５″）。     

越南中新世滨海炭酸盐岩隆

越南滨海碳酸盐岩多种多样,其中,受巨大的断层控制并因抬升而遭受广泛淋滤作用的大岩隆可以形成最好的储层。多数具有等储集性能的储发育于分布范围很广的台地相和断层下盘顶部的小岩隆中。本文讨论各种不同类型碳酸盐岩的岩层,岩相,成岩作用和储层性质。     

Spatial variation of metal bioaccumulation in the hydrothermal vent mussel Bathymodiolus azoricus

The variability of the bioaccumulation of metals (Ag, Cd, Cu, Fe, Mn and Zn) was extensively studied in the mussel Bathymodiolus azoricus from five hydrothermal vent sites inside three main vent fields of increasing depth along the Mid-Atlantic Ridge: Menez Gwen, Lucky Strike and Rainbow. Metal bioaccumulation varied greatly between vent fields and even between sites inside a vent field with B. azoricus showing a great capacity to accumulate metals. The bioaccumulation of these metals also varied significantly among tissues. The main target was the gills where metals were mainly associated with soluble compounds whereas in the digestive gland they were mainly associated with insoluble compounds. Storage of metals under insoluble forms in B. azoricus seems to be a major pathway for the detoxification of both essential and non-essential metals. Mussels from the studied fields can be discriminated following their metallic load but the segregation relies partially on the composition of the metal-enriched fluids.     

高美古水汽含量的观测

介绍了利用北京师范大学研制的ＩＲＡ－９３５型红外水汽测量仪对丽江高美古天文候选点上空垂直大气水汽积分含量Ｗ０的观测情况。给出了Ｗ０的各种变化曲线及在雨季和旱季的Ｗ０分布。结果表明：高美古上空垂直大气水汽积分含量雨季平均为１６．３０９ｍｍ，旱季平均为５．０９９ｍｍ。     

Dissolution kinetics of a lunar glass simulant at 25 degrees C: the effect of pH and organic acids

The dissolution kinetics of a simulated lunar glass were examined at pH 3, 5, and 7. Additionally, the pH 7 experiments were conducted in the presence of citric and oxalic acid at concentrations of 2 and 20 mM. The organic acids were buffered at pH 7 to examine the effect of each molecule in their dissociated form. At pH 3, 5, and 7, the dissolution of the synthetic lunar glass was observed to proceed via a two-stage process. The first stage involved the parabolic release of Ca, Mg, Al, and Fe, and the linear release of Si. Dissolution was incongruent, creating a leached layer rich in Si and Ti which was verified by transmission electron microscopy (TEM). During the second stage the release of Ca, Mg, Al, and Fe was linear. A coupled diffusion/surface dissolution model was proposed for dissolution of the simulated lunar glass at pH 3, 5, and 7. During the first stage the initial release of mobile cations (i.e., Ca, Mg, Al, Fe) was limited by diffusion through the surface leached layer of the glass (parabolic release), while Si release was controlled by the hydrolysis of the Si-O-Al bonds at the glass surface (linear release). As dissolution continued, the mobile cations diffused from greater depths within the glass surface. A steady-state was then reached where the diffusion rate across the increased path lengths equalled the Si release rate from the surface. In the presence of the organic acids, the dissolution of the synthetic lunar glass proceeded by a one stage process. The release of Ca, Mg, Al, and Fe followed a parabolic relationship, while the release of Si was linear. The relative reactivity of the organic acids used in the experiments was citrate > oxalate. A thinner leached layer rich in Si/Ti, as compared to the pH experiments, was observed using TEM. Rate data suggest that the chemisorption of the organic anion to the surface silanol groups was responsible for enhanced dissolution in the presence of the organic acids. It is proposed that the increased rate of Si release is responsible for the one stage parabolic release of mobile cations and the relatively thin leached layer compared to experiments at pH 3 and 5.     

Implementation of the European water framework directive from the Basque country (northern Spain): a methodological approach

The European Water Framework Directive provides a challenge in the development of new and accurate methodologies. It addresses assessment of Ecological Quality Status within European rivers, lakes, groundwaters, estuaries and coasts. Although this directive is simple and flexible in its concept, it is necessary to develop an approach based upon scientific knowledge; however, at the same time it should be as simple as possible, in order to achieve both requirements and comparability of results throughout European waters. This contribution presents the first methodological approach to the problem, as used for estuaries and coasts of the Basque Country (northern Spain), in: selecting typologies and reference conditions; determining biological quality and ecological status; and identifying some problems in implementing the WFD. As such, the present paper could serve as the basis for a discussion document for other regions and countries, throughout Europe.     

Biodegradation of petroleum products in experimental plots in Antarctic marine sediments is location dependent

Clean sediment collected from O'Brien Bay, East Antarctica, was artificially contaminated with a mix of Special Antarctic Blend diesel fuel and lubricating oil and deployed in two uncontaminated locations (O'Brien and Sparkes Bays) and a previously contaminated bay (Brown Bay) to evaluate whether a history of prior contamination would influence the biodegradation process. Detailed analysis of the hydrocarbon composition in the sediment after 11 weeks revealed different patterns of degradation in each bay. Biodegradation indices showed that hydrocarbon biodegradation occurred in all three bays but was most extensive in Brown Bay. This study shows that even within a relatively small geographical area, the longevity of hydrocarbons in Antarctic marine sediments can be variable. Our results are consistent with faster natural attenuation of spilt oil at sites with previous exposure to oil but further work is needed to confirm this. Such information would be useful when evaluating the true risk and longevity of oils spills.     

Factors affecting marine debris deposition at French Frigate Shoals, Northwestern Hawaiian Islands Marine National Monument, 1990-2006

Data on the amount and type of small debris items deposited on the beaches of the Hawaiian Islands National Wildlife Refuge Tern Island station, French Frigate Shoals were collected over 16 years. We calculated deposition rates and investigated the relationship among deposition and year, season, El Ni?o and La Ni?a events from 1990 to 2006. In total 52,442 debris items were collected with plastic comprising 71% of all items collected. Annual debris deposition varied significantly (range 1116-5195 items) but was not influenced by season. Debris deposition was significantly greater during El Ni?o events as compared to La Ni?a events. Although often deduced to influence floating marine pollution, this study provides the first quantitative evidence of the influence of El Ni?o/La Ni?a cycles on marine debris deposition.