泡沫潜孔锤在水文水井钻探中的应用前景   总被引：3，自引：1，他引：2  

菅志军  崔颖等 《地质与勘探》2001,37(5):77-78

介绍了泡沫潜孔锤的结构及工作原理,阐述了其优点及在水井钻探中的应用前景。  相似文献   

安装期单层保温管层间剪切力分析     

闫澍旺田英辉  周宏杰杨晓刚 曹静 《海洋工程》2005,23(3):17-22

在浅水海域,采用单层保温管结构代替双重钢管保温结构具有很好的发展应用前景,但在单层管的铺设过程中管线各层之间和保温层内将产生较大的剪应力,如何防止各层间的错动和保温层材料的剪切破坏是设计所必须解决的两个主要问题。以渤海某油田海底管线建设项目为例,根据单层保温管的结构特点,力的层间传递特性和变形协调条件,建立了单层保温管各层层间剪切力和保温层中剪应力的计算方法,为海底单层保温管的设计提供了依据。  相似文献   

Occurrence, distribution and characteristics of beached plastic production pellets on the island of Malta (central Mediterranean)     

Turner A  Holmes L 《Marine pollution bulletin》2011,62(2):377-381

The distribution, abundance and chemical characteristics of plastic production pellets on beaches of the island of Malta have been determined. Pellets were observed at all locations visited and were generally most abundant (>1000 m⁻² at the surface) on the backshores of beaches with a westerly aspect. Most pellets were disc-shaped or flattened cylinders and could be categorised as white, yellow, amber or brown. The polymeric matrix of all pellets analysed by infrared spectroscopy was polyethylene and the degree of yellowing or darkening was associated with an increase in the carbonyl index, hence extent of photo-oxidation or aging. Qualitatively, pellets are similar to those reported for other regions of the Mediterranean in surveys spanning three decades, suggesting that they are a general and persistent characteristic of the region.  相似文献   

Plastic contamination in the decapod crustacean Nephrops norvegicus (Linnaeus, 1758)     

Murray F  Cowie PR 《Marine pollution bulletin》2011,62(6):1207-1217

The aim of this study was to determine the extent Nephrops consumes plastics in the Clyde Sea and if this intake occurs through their diet. Plastic contamination was found to be high in Nephrops, 83% of the animals sampled contained plastics (predominately filaments) in their stomachs. Tightly tangled balls of plastic strands were found in 62% of the animals studied but were least prevalent in animals which had recently moulted. No significant difference in plastic load was observed between males and females. Raman spectroscopy indicated that some of the microfilaments identified from gut contents could be sourced to fishing waste. Nephrops fed fish seeded with strands of polypropylene rope were found to ingest but not to excrete the strands. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland and the high prevalence of plastics in Nephrops may have implications for the health of the stock.  相似文献   

Plastic marine debris on the Portuguese coastline: a matter of size?     

Martins J  Sobral P 《Marine pollution bulletin》2011,62(12):2649-2653

Plastic debris is a worldwide threat to marine environments and Portugal is not immune to it. Though never quantified, items of all sizes can be found in the Portuguese coastline; therefore the objective of this work is the identification of main size classes in stranded plastic debris. Beaches sediment was sampled and in the laboratory plastic items were sorted in 11 classes from <1 to >10 mm, counted and weighted. Plastic size ranged from 50 μm to 20 cm and microplastics (<5 mm) were the majority (72%). Most plastic fits in the smaller size classes, due to expected high residence time in the sea enhancing degradation processes, which increase surface exposure and potentially persistent organic pollutants (POP) adsorption. These results point out the important contribution of microplastics to marine debris pollution, its risks, and the need to set a higher focus on this size class.  相似文献   

Research on experiment and calculation of foam bursting device     

References： 《东北亚地学研究》2007,10(1):34-38

This research presents experimental data on mechanical foam bursting device,based on the high speed of air fluid impinging insidethe foam bursting device,foam bubbles disrupted as a consequence of pressures changed very quickly as shear force and their impact forces.Experimental data on foam-bursting capacity have been presented.Designed device can provide effective foam bursting on collapse foam.  相似文献   

Rethinking rewilding     

《Geoforum》2015

The term ‘rewilding’ sounds as if it should have a straightforward meaning ‘to make wild again’. But in truth the term has a complex history and a host of meanings have been ascribed to it. Rewilding as a specific scientific term has its beginnings as a reference to the Wildlands Project, which was founded in 1991 and aimed to create North American core wilderness areas without human activity that would be connected by corridors. Words, however, do not stand still—they change over time and take on new meanings, while sometimes simultaneously retaining the older sense. Employing Foucault’s idea of historical genealogy, this article examines how the term rewilding was historically adopted and modified in ecological scientific discourse over the last two decades. This investigation probes what and, by extension, when and where, rewilding refers to as it has moved into various geographies across the globe. It then examines how the term has moved outside of science and been adopted by environmental activists as a plastic word. Taken as a whole, rewilding discourse seeks to erase human history and involvement with the land and flora and fauna. Such an attempted split between nature and culture may prove unproductive and even harmful. A more inclusive rewilding is a preferable strategy.  相似文献   

Constitutive modelling of Otaniemi soft clay in both natural and reconstituted states     

《Computers and Geotechnics》2015

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用于高温地热井泡沫水泥泡沫剂性能研究   总被引：1，自引：0，他引：1  

谭慧静 《地质与勘探》2015,51(6):1181-1186

地热井钻井具有高温、地层压力低、地层破碎等特点,采用抗高温泡沫水泥进行固井,要求泡沫剂具有一定的抗高温性能。本文评价和优选了多种泡沫剂在常温和180℃高温下的起泡能力、稳定性,并且将优选出来的单种发泡剂进行复配评价,得到最佳的复配体系为SLES∶CAO∶CAB=63.3∶31.7∶5,并且与单种发泡剂进行比较,将所得最佳复配体系加入到API G级油井水泥体系中进行性能的初步评价。  相似文献   

Asteroidal processes recorded by polyphase deformation in a harzburgitic diogenite NWA 5480     

《Journal of Structural Geology》2015

Expectations regarding structural deformation of asteroidal meteorites have typically revolved around impact-induced shock metamorphism or the gravity-driven axial compression of cumulates at the base of magma chambers. Recent structural analyses, however, of several olivine-rich diogenites (harzburgites) reveal solid-state plastic deformation not attributable to either scenario and propose dynamic mantle movements in the parent body, assumed to be Vesta. In this study we examine the microstructures of pyroxene and olivine in the olivine-rich diogenite NWA 5480. Coarse-grained, poikilitic texture, exsolution lamellae and plastic deformation attest to polyphase deformation and a re-heating event, followed by relatively slow cooling. Observations suggest that impact events alone are insufficient to generate and sustain the thermal and deformation conditions required to achieve all of the observed features. The proposed dynamic mantle movements in the Vestan interior may offer a means of heat transport to the system to provide a thermal environment inducive to slow cooling as well as generate the incremental stress fields required for the polyphase plastic deformation observed in the olivine.  相似文献