Effect of prolonged hypoxia on food consumption, respiration, growth and reproduction in marine scavenging gastropod Nassarius festivus

The effects of prolonged exposure to reduced oxygen levels (3.0 and 1.5 mg O(2)l(-1)) on marine scavenging gastropods Nassarius festivus were studied for 8 weeks. The percentages of individuals engaged in feeding and amount of food consumed were reduced as oxygen level decreased; absorption efficiency, however, did not vary significantly with oxygen level. Oxygen consumption rates and specific oxygen consumption rates were lower at reduced oxygen levels. Reproduction occurred at all oxygen levels with less egg capsules being produced at lower oxygen levels. Egg size and number of eggs per capsule, however, were not significantly affected by oxygen level. The increase in shell length was 12%, 6% and 5% at 6.0 mgO(2)l(-1) (normoxia), 3.0 mgO(2)l(-1) and 1.5 mgO(2)l(-1), respectively. At the end of the experiment, the amount of energy allocated to growth and reproduction decreased at reduced oxygen levels with values obtained at 3.0 mgO(2)l(-1) and 1.5 mgO(2)l(-1) being 48% and 70% lower than those at 6.0 mgO(2)l(-1). At all oxygen levels, most of the accumulated energy was allocated to shell growth and reproduction, and the amount allocated to somatic growth was relatively insignificant. The reduction in energy allocated to reproduction was greater than that to shell growth as the oxygen level was reduced, indicating a strategic energy allocation of marine scavengers under stressful conditions to enhance survival.     

Ecological consequences of dredged material disposal in the marine environment: a holistic assessment of activities around the England and Wales coastline

This study provides a holistic perspective on the ecological effects of dredged material disposal, both intertidally and subtidally. A number of numerical techniques (univariate, distributional, multivariate and meta-analysis) were used to assess impacts at 18 different disposal sites. The analyses revealed that ecological effects associated with dredged material disposal were dependent on the numerical techniques used, and that impacts were disposal-site specific. Disposal-site communities were generally faunistically impoverished to varying degrees, and impacts following intertidal placement were comparable to those of subtidal placement. We conclude that any assessment of the consequences of dredged material disposal to the coastal environment must take account of site-specific variation in prevailing hydrographic regimes and in ecological status, along with information on the disposal activity itself (mode, timing, quantity, frequency and type of material). As would be expected, variability in the latter presents a significant challenge in attempts to generalise about environmental and ecological impacts.     

存在低刚性不均匀体情况下的走滑断裂

在含有椭圆包体的介质中，利用由３型裂纹组成的二维模型分析了不均匀介质中的走滑断裂，以例评估局部或层状不均匀体对断裂发展的影响，表征和控制不均匀介质中断层的主要特征是有效剪切应力的空间变化，有效剪切应力变化范围可解释同一地区的地震事件的各种不同应力降值，在含有低刚性不均匀体的介质中的应力场最明显特征是在不均匀体内有效剪切应力大幅度减少，这个结果可以用来解释沉积层中动态扩展的破裂受到抑制作用，同时它也     

Animating ground water levels with Excel

This note describes the use of Microsoft Excel macros (programs written in Excel's internal language, Visual Basic for Applications) to create simple onscreen animations of transient ground water data within Excel. Compared to many specialized visualization software packages, the use of Excel macros is much cheaper, much simpler, and can rapidly be learned. The Excel macro can also be used to create individual GIF files for each animation frame. This series of frames can then be used to create an AVI video file using any of a number of graphics packages, such as Corel PhotoPaint. The technique is demonstrated through a macro that animates changes in the elevation of a water table along a transect over several years.     

海洋半球台网计划(OHP)与海底地震观测系统的发展

简述了基于海洋半球台网计划(OHP),由日本建立的OHP地震台网、OHP数据中心,日本研制的海底地震观测系统,由ODP(大洋深钻计划)Leg191布设的海底钻孔宽频带地震观测站的总体进展.也阐述了近年来我国自行研发的海底地震观测系统的现状,并提出在我国沿海大陆架海域筹建海底钻孔式长期地震观测站的建议与设想.     

地电化学方法在勘探深部矿床中的一些实际应用

世界上对于利用地球化学方法寻找深部矿床的研究日益增加，这种研究建立在对土壤中各种元素的赋存状态进行分析的基础上。这篇文章中作者在２０年的实践基础上，讨论了地电化学方法的各种改正。     

Development of macrofaunal communities on dredged material used for mudflat enhancement: a comparison of three beneficial use schemes after one year

In recent years, dredged material has become regarded as a potential resource and used to create and/or improve intertidal habitats ('beneficial use' schemes). This paper presents the results of a sampling programme to investigate the short-term macrofaunal recovery of three beneficial use schemes in south-east England in terms of species and functional diversity. Environmental parameters (sediment redox potential, and water, organic carbon and silt/clay contents) and univariate community attributes (total individuals and species, diversity, evenness and biomass) at the recharge sites had attained reference levels at two schemes while assemblages differed significantly in terms of species composition at all three schemes. While trophic group proportionality had re-established at one scheme, an increased grazer dominance was apparent at another while the proportion of sub-surface deposit feeders decreased at the third. Total individuals and species number of the developing communities were negatively correlated with sediment redox potential at 4 cm and % silt/clay, respectively. The implications of these results for monitoring the recovery of future fine-grained beneficial use schemes are discussed.     

Occurrence and accumulation features of polycyclic aromatic hydrocarbons and synthetic musk compounds in finless porpoises (Neophocaena phocaenoides) from Korean coastal waters

Reports of the occurrence and accumulation patterns of polycyclic aromatic hydrocarbons (PAHs) and synthetic musk compounds (SMCs) in marine mammals are scarce. In this study, the concentrations and accumulation profiles of PAHs and SMCs were determined in blubber from finless porpoises in Korean coastal waters. Total concentrations of PAHs and SMCs ranged from 6.0 to 432 (mean: 160) ng/g lipid weight and from 17 to 144 (mean: 52) ng/g lipid weight, respectively. Residue levels of PAHs were lower than those reported from other studies, while residue levels of SMCs were relatively higher than those reported in other studies. Naphthalene was the most abundant PAH and HHCB was the dominant SMC observed in finless porpoises. The concentrations of PAHs and SMCs were not correlated with each other, but were significantly correlated within the same chemical groups. No correlations were found between body size and residue levels of PAHs and SMCs.