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431.
从水文地质的角度揭示了不同情况下单井的排水采气机理。在此基础上结合柿庄南区块59口井的实际排采数据,综合分析了气水产量,井底流压,套压及动液面随时间的变化曲线;并将早期生产特征归纳为3种类型:①低产水-高产气型,见气早,产气量高(>1000 m3/d)、产量递减缓慢、峰值产量高,日产水量小(<2m3/d),套压高;②低产水-中低产气型,日产气小于1000 m3,产量衰减明显且波动大,排水期较长;③高产水型,产气极少或无,日产水量大(>10m3/d),动液面下降缓慢,套压很低或为零。最后针对不同类型的低产井,提出相应的开采建议:低产水-低产气型井可采用二次压裂措施,改善煤层渗透率;高产水井可通过无机堵水或加大排采强度等方式排采;煤层气井排采要勇于实践,探索适合该区不同煤层的成功排采方法。 相似文献
432.
433.
热流─生热率线性关系研究综述 总被引:1,自引:0,他引:1
热流-生热率线性关系的发现被视为理论地热学上的一次重大突破,目前在全球范围内已定义了数十个热流省。但是,这一线性关系至今仍缺乏可信的理论基础。本文概述了热流-生热率线性关系的发展历史,综合介绍了20多年来在地质、地球化学和地球物理等方面为正确理解这一经验线性关系的内在涵义而展开的研究,并对现有大陆热流省的资料进行了分析。 相似文献
434.
跨国公司对区域经济发展影响的理论研究 总被引:9,自引:0,他引:9
(1)根据相邻学科的理论并基于前人研究成果,提出跨国公司对区域经济影响、跨国公司与区域关系以及两者关系的决定因素三层次研究思路;(2)以生产链、组织链和所有权关系三个关联系统和区域等级关系作为跨国投资的理论背景,导出跨国公司──区域综合分析方法;(3)跨国投资对区域发展影响具广泛性、层次性、区域性、多面性、差异性和时间性特点,跨国公司与投资地关系具互补性、竞争性和变化性特点,影响两者关系的主要因素为社会政治背景、结构状况和相对地位。 相似文献
435.
This study presents a semi-empirical model for quantifying the reduction in the mechanical strength of bedrock beneath actively eroding soil-mantled hillslopes. The strength reduction of bedrock controls the rate of physical disintegration of saprolite, which supplies fresh minerals that are then exposed to intense chemical weathering in soil sections. To determine the values of parameters employed in the model requires knowledge of the denudation rate of the hillslope, the thickness of the soil and saprolite layers, the strength of fresh bedrock, and the threshold strength for physical erosion at the uppermost face of the saprolite. These parameters can be obtained from cosmogenic nuclide analyses for quartz samples from the soil–saprolite boundary and basic field- and laboratory-based investigations. Further testing of the model within a diverse range of climatic, tectonic, and lithologic environments is likely to provide clues to the mechanisms responsible for local and regional variations in the rates of soil production and chemical weathering upon hillslopes. 相似文献
436.
Transport of oceanic nitrate from the continental shelf to the coastal basin in relation to the path of the Kuroshio 总被引:1,自引:0,他引:1
Ryo Sugimoto Akihide Kasai Toshihiro Miyajima Kouichi Fujita 《Continental Shelf Research》2009,29(14):1678-1688
Hydrographic and biogeochemical observations were conducted along the longitudinal section from Ise Bay to the continental margin (southern coast of Japan) to investigate changes according to the Kuroshio path variations during the summer. The strength of the uplift of the cold deep water was influenced by the surface intrusion of the Kuroshio water to the shelf region. When the intrusion of the Kuroshio surface water to the shelf region was weak in 2006, the cold and NO3−-rich shelf water intruded into the bottom layer in the bay from the shelf. This bottom intrusion was intensified by the large river discharge. The nitrogen isotope ratio (δ15N) of NO3− (4–5‰) in the bottom bay water was same as that in the deeper NO3− over the shelf, indicating the supply of new nitrogen to the bay. The warm and NO3−-poor shelf water intruded into the middle layer via the mixing region at the bay mouth when the Kuroshio water distributed in the coastal areas off Ise Bay in 2005. The regenerated NO3− with isotopically light nitrogen (δ15N=−1‰) was supplied from the shelf to the bay. This NO3− is regenerated by the nitrification in the upper layer over the shelf. The contribution rate of regenerated NO3− over the shelf to the total NO3− in the subsurface chlorophyll maximum layer in the bay was estimated at 56% by a two-source mixing model coupled with the Rayleigh equation. 相似文献
437.
The ecological tidal model simulates the cycling of carbon, nitrogen, phosphate, and silicate and describes the tidal, diurnal,
and annual dynamics of the back barrier area of the island Spiekeroog in the German Bight. The region is characterized by
strong tidal currents and extensive tidal flats. It is strongly influenced by the conditions in the southern part of the German
Bight. This model study investigates the dependence of the model behavior on the boundary conditions and the forcing. The
effect of short- and long-term sea level rise on nutrient and plankton dynamics is analyzed. As the model is set up as semi-Lagrangian
with only a coarse approximation of the hydrodynamics, the seasonal and intratidal variability in the biogeochemical cycling
can only be reproduced qualitatively. By varying the boundary conditions, the intrinsic dynamics of the back barrier area
can be separated from boundary condition effects. This study shows that any agreement between model results and field data
cannot be expected without correct boundary conditions. The seasonal variability is of major importance, while higher-frequency
variability only plays a minor role. 相似文献
438.
439.
Michael Sofer 《Singapore journal of tropical geography》2009,30(3):343-357
This paper reviews changes in the development and peripheralized status of the Fijian island of Kadavu from a 20‐year perspective. A combination of microgeographic studies in three villages and a mesogeographical analysis show that the conditions of internal dependency found in Kadavu in the early 1980s had not changed much: the pattern of cash crop production and trade remained almost entirely dependent on the yaqona (Pacific kava) beverage crop; shipping services provided by core agents had not improved; the island had experienced significant outmigration; and government initiatives to change the trend were limited. These elements perpetuate a core–periphery structure in Fiji that hampers the development of a self‐sufficient periphery. For Kadavu villagers, however, the benefits derived from the continued form of non‐capitalist production afford them a certain degree of autonomy vis‐à‐vis the market economy, which might be to their advantage under the ongoing conditions of peripheralization. 相似文献
440.
本文从对震害进行分析和研究的目的出发,讨论了航空遥感飞行与影像图制作的有关技术和实施问题,主要包括在震害研究和调查中,航摄与制图比例尺的选择、航空遥感飞行的方案设计、利用影像图进行震害研究分析的优越性及系列震害专题影像图的确定与制作特点等内容。 相似文献