QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAU

QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAUgrants 49732 0 90and 496 0 2 0 36fromtheNSFofChina     

四川马脑壳层控金矿床中辉锑矿残余沉积组构的发现及其 …

在川西北马脑壳层控Ａｕ－Ｓｂ－Ｗ建造矿床中,发现了辉锑矿的显微沉积层纹状组构。由细晶辉锑矿和自生石英交替互层所显示的方向与辉锑矿的粒内变形作用以及晶体粒度变化所显示的方向一致,也与矿石和围岩的宏观－微观层理一致。这一组构代表了一种保留有沉积成因先存组构残余的次生组构。     

Biosecurity risks associated with in-water and shore-based marine vessel hull cleaning operations

The removal of biofouling from vessels during hull cleaning can pose a biosecurity threat if viable, non-indigenous organisms are released into the aquatic environment. However, the effect of cleaning on biofouling organism viability in different types of cleaning operations has been poorly studied. We compared the effects of hull cleaning on biofouling organisms removed from 36 marine vessels during in-water (without capture of cleaning waste) and shore-based (with capture, and treatment of cleaning waste) cleaning. In-water cleaning resulted in higher proportions of viable biofouling organisms surviving cleaning (62.3 ± 7.1% of all organisms examined) compared to dry dock (37.8 ± 8.6%) and haul-out (20.1 ± 5.3%) operations. For shore-based facilities with effluent treatment systems, concentrations of organisms and/or their propagules in cleaning effluent was reduced by ≥ 98.5% compared to initial hydro-blast effluent concentrations. These results can be used in guidance for hull cleaning operations to minimize associated biosecurity risk.     

Optimization for performance-based design under seismic demands,including social costs

Performance-based design in earthquake engineering is a structural optimization problem that has, as the objective, the determination of design parameters for the minimization of total costs, while at the same time satisfying minimum reliability levels for the specifi ed performance criteria. Total costs include those for construction and structural damage repairs, those associated with non-structural components and the social costs of economic losses, injuries and fatalities. This paper presents a general framework to approach this problem, using a numerical optimization strategy and incorporating the use of neural networks for the evaluation of dynamic responses and the reliability levels achieved for a given set of design parameters. The strategy is applied to an example of a three-story offi ce building. The results show the importance of considering the social costs, and the optimum failure probabilities when minimum reliability constraints are not taken into account.     

2010年海地地震的复杂破裂机制与地形控制的滑坡样式对称性

2010年1月12日的Mw7．0海地地震发生在北美板块与加勒比板块交界的复杂形变区域。综合大地测量、地质和地震数据断定,地表变形是由莱奥甘逆冲盲断层破裂驱动的,而部分破裂为发生在恩里基约普兰廷加登断层（EPGF）上的深侧向滑移。这次地震触发了至少4490处滑坡,主要为浅层的扰动碎屑流、泥石一土质崩塌与滑落,以及一些侧向滑移,分布面积约为2150km^2。这些滑坡的区域分布特征与大部分类似的以前地震触发滑坡事件报告不同。大部分同震滑坡并没有发生在主破裂的上盘,而是聚集在莱奥甘盲破裂与恩里基约一普兰廷加登断层盲破裂的交汇处,这里的地形起伏和斜坡陡度均高于平均值。此外,遭受到高同震上升的低地形起伏区域倾向于比以往研究中认为的上盘更容易发生滑坡。我们认为复杂的破裂动力学与地形的综合影响主要控制了这种以前研究中很少记录的地震滑坡样式。对比近期其他地区相似震级的逆断型地震事件我们得出结论,2010年海地地震的较低静态应力降、平均断层位移和盲破裂导致了比以往研究表现出更少、更小和更对称的滑坡分布。我们的结果提醒不要过分依靠全面的边坡稳定性地震动响应模型。     

Assessment of the bioavailability and toxicity of sediment-associated polycyclic aromatic hydrocarbons and heavy metals applied to Crassostrea gigas embryos and larvae

Sediments represent a vast sink for contaminants in aquatic systems, and may pose a threat to pelagic and benthic organisms. The objective of this research was to determine the bioavailability and toxicity of sediment-associated PAHs and heavy metals, using embryos and larvae of the oyster Crassostrea gigas, exposed to two sediment fractions: the whole sediment and the elutriate. The percentages of abnormal larvae, the contaminant accumulation and, (in the case of metal contamination), the induction of metallothionein in the larvae, were investigated. Sediment-associated PAHs and heavy metals were available for exposure, as indicated by their accumulation in C. gigas larvae and by the abnormalities induced during larval development. The critical body burden of PAHs (Fluo, Pyr, BaA, Triph, Chrys, BbF, BkF, BjK, BeP, BaP, Per, IP, BPer and the DahA) in the larvae was 0.3 micro g g(-1), above which abnormalities were observed. This value corresponds to concentrations observed for most vertebrate and invertebrate species. The bioavailability of PAHs is determined by their solubility; only the soluble fraction of PAHs is accumulated by the embryos. The bioavailability of metals for the larvae is substantiated by MT induction, correlated with cytosolic metal concentrations. MT induction provided a better early-warning response than the embryotoxicity test currently used for evaluating environmental contamination by metals. This study recommends choosing oyster embryos as a particularly sensitive tool for evaluating sediment quality.     

Impacts of the Nakhodka heavy-oil spill on an intertidal ecosystem: an approach to impact evaluation using geographical information system

A major heavy-oil spill from the Russian tanker Nakhodka occurred in the Sea of Japan on 2 January 1997. We investigated the impacts of this spill on a rocky intertidal ecosystem along the southern coast of the Sea of Japan. We selected Imago-Ura Cove as our study site to observe temporal changes along the oiled shore, because minimal cleaning effort was made in this area. Field surveys were conducted every autumn and spring from 1997 to 2000. We measured coverage by macroalgae in 1 x 1-m(2) quadrats and counted the animals in 5 x 5-m(2) quadrats along the intertidal zone. Changes in the ecosystem caused by the oil spill were analyzed by applying a geographical information system (GIS) to the Sea of Japan for the first time. The GIS showed that following the accident there were heavily oiled areas in sheltered regions, but these decreased over the three years. It also showed that coverage by macroalgae and the number of animals increased, although some species of algae with microscopic sporophyte generations, and some populations of perennial shellfish, remained stable or decreased during the study period. GIS was able to trace temporal changes in intertidal communities resulting from the impacts of heavy oil on flora and fauna at a spatial scale of 10-100 m. GIS is thus a practical tool for visualizing, analyzing, and monitoring changes in an ecosystem polluted by oil, taking into account topographic differences along the coastline.     

农村服务业的空间组织——区域发展规划的可操作性模型

引言包括生产和流通中所需的自然和公共的基础设施在内的基础服务业的重要性像社会和文化环境一样已被多次指出来(约翰逊.1970;艾莫斯,1977)。很显然,农村村落由于它们的分散性和低密度,使得每一个人较城市人口有更高的服务性消费。同时,农村服务业的质量都很低,在由于贫穷、缺乏便利的交通而萧条的区域中,必然会存在问题。在许多涉及仅能维持生存阶段、从事传统耕作业的开发规划中,这些相距遥远、分布稀疏的人口,在服务业结构的组织中成为主要的限制性因素。     

恒星的自转

本文由统计的观点讨论三个物理问题:(1)自转恒星的角动量的来源,(2)作一星团之内自转和空间运动的关联,(3) 超巨星是否有相当大的自转。我们的结论是一个恒星的自转角动量可能是由星胚(proto-stars)间或甚至是产生它的物质云间的碰撞引起的。理由是:(a)观测到的恒星自转和它的银线并无关联,(b)属于物理性质不同的集团的星的平均自转速度可以有很大的差别,(C)在天蝎一半人马座B型星团内的恒星自转和它们的内部运动是关联关的:对于星团本身运动得快的星有较快的自转速度。最后一节述及对于由测量得的超巨星光普线宽度推知的速度的解释。这结果和以前所提出的两种超巨星模型均无抵触。