Pressure Tight Piston Corer ——A New Approach on Gas Hydrate Investigation

A pressure tight sediment samphng technology, which can be introduced into the modification of the piston corer to accommedate the investigation of gas hydrate, is put forward. In this paper, the three basic rules of the technology are analyzed in detail: specimen transferring rule, seal self-tightening rule and semi-active pressure holding rule. Based on these, the structure of the pressure tight piston corer is put forward and its working principle is analyzed. Finally, a pressure tight sediment sampler, to which the same technology is apphed, is researched through experiments. Results show that the sampler based on the above-mentioned theory has a good ability in samphng and in -situ pressure holding.     

A sediment core sectioning method to minimize the post-sampling redistribution of organisms

We present a mechanical method to horizontally section soft bottom sediment cores to minimize the vertical post-sampling redistribution of motile infaunal macroinvertebrates. A clear acrylic core tube for a standard Kajak-Brinkhurst corer was modified by cutting a series of horizontal slits into the side of the core tube to allow the insertion of sectioning plates for physically sealing each section immediately after core retrieval. The modification is simple, inexpensive and easily adapted to any open barrel gravity corer.     

The design and performance of a new box corer for collecting undisturbed samples of soft subaquatic sediments

The Baikal sediment box corer represents an innovation in design of the closing mechanism and involves a single, thin, and flexible stainless steel blade rather than closing jaws. With this light-weight box corer only a relatively small cross-sectional area is offered to the sediment, allowing easier penetration. The closure blade is propelled smoothly across the base of the box in a downwardly convex path by a set of constant force springs. Depending on choice of blade-release mechanisms, the corer can either be triggered immediately as the support cable slackens, after a delay of a few seconds, or immediately upon retrieval. The box corer has been used successfully to sample poorly consolidated sediments in freshwater lakes over a depth range of 8 to 1624 m. Cores of deep-water surficial sediment from Lake Baikal were tested for representativity and replicability by profiling natural and artificial radioisotopes and lithostratigraphic features.     

重力活塞取样器贯入深度研究

重力活塞取样器是一种重要的海底连续沉积物采集仪器,贯入深度和样品质量对海洋地质研究有着重要影响。通过对重力活塞取样器贯入过程建立能量守恒方程,得出贯入深度控制方程。已知取样器参数和土质类型条件,可计算取样管贯入深度,深度受取样器重量、体积、形状、取样管直径和沉积物类型等因素共同影响。已知取样器参数和贯入深度,可推测海底沉积物类型。     

新型超声波钻探设备的建模分析

目前,对宇宙中生命迹象的探索是世界各国所关注的最重要的目标之一。美国宇航局研制了由超声波或者声波驱动器驱动的一系列超声波／声波钻头／取心器（USDC）设备,用来进行空间探测并提取岩石、冰与土壤样品,以及进行原位分析。此设备在声波频率下,超声波压电驱动器驱动中间的自由质量块,进而冲击钻头来进行采样。基于此设备的运行过程,分析了超声波激发器的原理过程,主要是自由质量块与激发器的反应过程,变幅杆顶部与自由质量块的碰撞过程,自由质量块与钻杆的碰撞过程。初步建立了USDC内部各部分相互作用的模型。     

新型液压活塞取样钻具的研制

江、河、湖、泊等水域取样是环境科学研究与资源勘查必不可少的工作。本项研究提供了一种适合水域取样的新型钻具——液压活塞取样钻具。与传统的活塞钻具相比,具有取样效率高、对地层适应能力强的特点。主要介绍了该钻具的结构及工作原理。     

The HTH sediment corer

Gravity corers have been in use for a long time and in many different configurations. There are, however, reasons for improvements since new manufacturing materials have become available, and demands for accurate coring and sub-sampling in both research and environmental monitoring have increased. The HTH-coring equipment, which has been tested for >10 years by several users, is a further development of the Kajak-corer concept and has some unique features which are described here. To avoid contamination in pollution studies, the equipment is made of stainless steel and plastic (polyoxymethylene and polyethylene), and the use of these materials also makes the equipment more durable. The extruding device is the main improvement over previous versions. It consists of a piston that seals perfectly to the core tube wall, a threaded rod that can be mounted on a foot plate, and an extruder head with a stationary upper-half and a rotatable lower-half that is screwed along the rod. One 360°-turn gives a 5-mm thick sediment increment that is scraped off using the sectioning tray. Sub-sampling is quick and accurate and can be performed by one person. The equipment is constructed to allow coring and sub-sampling both in summer and winter.     

A simple closure mechanism for a compact,large-diameter,gravity corer

A simple and reliable corer closure mechanism is described, which has three principal advantages over published designs for similar automatic gravity corers. First, it allows the use of large diameter tubes (at least 80 mm internal diameter), reducing core shortening effects. Second, it allows free passage of water during descent minimising bow wave effects. Third, it is compact enough for convenient use through seasonal ice cover.