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排序方式: 共有263条查询结果,搜索用时 31 毫秒
1.
阐明了东山湾重矿物组合规律,物质来源,自生黄铁矿的富集与形成环境。研究表明,湾内重矿物含量<1%,来自漳江及周边水系。东山湾西部的沉积环境有利于自生黄铁矿的形成。 相似文献
2.
南黄海陆架沉积学研究 总被引:4,自引:0,他引:4
黄海中部、济州岛西南,存在厚层的泥质沉积,它们分别与上述地区的冷涡活动区相对应。在两个泥质沉积区之间又出现连接它们的通道,形成别有特征的“冷涡-通道”沉积体系。经分析发现,这个沉积体系,完全受控于黄海暖流、冷涡及其相关的环流体系。此外,在黄海西南部及东海北部海底发现大面积砂岩及其砾石,揭示了黄、东海陆架沉积物的新源地。 相似文献
3.
Integration of a Multi-Stage Bulk Materials Acquisition System from the Viewpoint of Dock Operations
Hong Tau Lee 《Marine Georesources & Geotechnology》2001,19(3):207-219
A multi-stage bulk materials acquisition system is examined from the viewpoint of dock operations. The whole process can be divided into four stages and treated as four subsystems: ships scheduling planning, material yard planning, dock arrangement, and material discharging. Since the structure and the complexity of each subsystem is different, the solution approaches applied are also different with respect to each. To increase operations efficiency and data consistency, an integration of the subsystems by coordinating the operations sequence and data communications for the four subsystems is discussed. The four subsystems are illustrated by using the material docks of China Steel Corporation, and the models developed in this research are also validated. The results indicate that the models developed are capable of deriving solutions better than the existing ones. Although the discussions are confined to China Steel Corporation, the models can be applied to other companies with similar operations. 相似文献
4.
In this study a field‐sampling technique for dissolved hydrogen (H2) in groundwater will be presented which allows the transport of gaseous samples into the laboratory for further analysis. The method consists of transferring the headspace trapped in a gas‐sampling bulb which is continuously purged by groundwater into previously evacuated vials using a gas‐tight syringe. Three transfer steps with preceding evacuation of the vial led to a H2‐recovery of 100 % in laboratory experiments. The method has been applied to determine H2 concentrations in an aquifer contaminated with chlorinated solvents. Tests concerning the effect of different pumping techniques on H2 concentrations revealed that most reliable values were obtained with a bladder pump, while an electrically driven submersible pump generated considerable amounts of hydrogen due to electrochemical interactions with the sampled water. Concentrations of dissolved hydrogen in field and laboratory samples were about two orders of magnitude higher when sampling was performed with the electrically driven submersible pump compared to sampling with the bladder pump and a peristaltic pump. Lab experiments with a Plexiglas reservoir to produce H2‐enriched water were used to study the effect of two tubing materials (PVC, polyamide) on H2 losses. PVC tubing turned out to allow transfer of H2‐enriched water over 25 m without significant losses, while PA‐tubing was not suitable for sampling of H2. 相似文献
5.
Review of Earth Critical Zone Research 总被引:2,自引:0,他引:2
Since the Earth Critical Zone put forward by National Research Council of America in 2001, it has got a lot of attention and some significant progresses have been made. This paper summarized those Earth Critical Zone projects and related research plans organized and implemented by the United States of America, Germany, Australia, France, China and the European Union, as well as main scientific problems and future development direction in the study of Earth Critical Zone. According to research status of China, the four main research contents should be strengthened including structure, formation and evolution mechanism of Earth Critical Zone, the coulpling interaction mechanism between migration and transformation of material and multi-processes, sevice function and evolution features of Earth Critical Zone and its support and effect on sustainable development, model simulation of process and system of Earth Critical Zone. In addition, our country should actively conduct cooperation and communication with the advanced countries, and enhance our involvement in international key research plans. 相似文献
6.
André Strasser 《Swiss Journal of Geoscience》2007,100(3):407-429
Detailed investigation of facies and sedimentary structures reveals that, during the Middle Oxfordian to Late Kimmeridgian,
the shallow carbonate platform of the Swiss and French Jura Mountains recorded high-frequency sea-level fluctuations quite
faithfully. The cyclostratigraphic analysis within the established biostratigraphic and sequence-chronostratigraphic framework
implies that the resulting hierarchically stacked depositional sequences formed in tune with the orbital cycles of precession
(20 kyr) and eccentricity (100 and 400 kyr). The astronomical time scale presented here is based on the correlation of 19
platform sections and 4 hemipelagic sections from south-eastern France where good biostratigraphic control is available. The
cyclostratigraphic interpretation suggests that the interval between sequence boundaries Ox4 and Kim1 (early Middle Oxfordian
to earliest Kimmeridgian) lasted 3.2 myr and that the Kimmeridgian sensu gallico has a duration of 3.2 to 3.3 myr. The astronomical time scale proposed here is compared to time scales established by other
authors in other regions and the discrepancies are discussed. Despite these discrepancies, there is a potential to estimate
the durations of ammonite zones and depositional sequences more precisely and to better evaluate the rates of sedimentary,
ecological and diagenetic processes.
Editorial handling: Hanspeter Funk, Helmut Weissert, Stefan Bucher 相似文献
7.
介绍北极星时角法测定天文方位角的基本方法,进而说明解析法测定天文方位角的基本原理,阐述计算软件的功能、菜单设计特点和操作方法,以实例说明软件的实用性。 相似文献
8.
中国东南沿海地震带大震重复性和大震减震作用 总被引:2,自引:0,他引:2
本文从物质分异的角度出发并利用现代小震活动资料,讨论了东南沿海地震带历史大震震源区及其附近,今后一段历史时期内是否有大震(M≥0)震源区大震重复性和大震减震作用问题。结果表明,这些历史震源区目前还处在减震阶段,今后一段时间只能以小震或中强地震的活动特点来显示这一弱化区。 相似文献
9.
1962—1986年JYD1968.0地极坐标的均匀化及其与BIH的比较 总被引:2,自引:0,他引:2
本文研究了1962-1986年JYD1968.0地极坐标均匀中星表系统差,章动系列的变动和光行星常数变动的影响,并将经过改正后的JYD1968.0地极坐标系统和BIH系统作了比较。 相似文献
10.