黄河断流对三角洲油气开发环境的影响

黄河断流对三角洲海上油气开发环境的负面影响是显著的,对流域的国民经济可持续发展的影响更是巨大。黄河断流对整个流域海上开发环境的影响深远,解决起来是一个很大的系统工程。从1999年的情况看,由于各级领导重视和措施得当,黄河断流的状况已得到很大缓解,黄河断流已由先前百天以上减少到1999年只断流41d(利津站)。2000年至今,黄河尚未发生过断流。本文从许多学者的研究资料入手,讨论黄河断流对三角洲油气开发环境的影响。     

Characteristics and Formation Mechanism of Giant Long‐Runout Landslide: A Case Study of the Gamisi Ancient Landslide in the Upper Minjiang River,China

The upper reaches of the Minjiang River are in the eastern margin of the Tibetan Plateau, where active faults are well developed and earthquakes frequently occur. Anomalous climate change and the extremely complex geomechanical properties of rock and soil have resulted in a number of geohazards. Based on the analysis of remote sensing interpretations, geological field surveys, geophysical prospecting and geological dating results, this paper discusses the developmental characteristics of the Gamisi ancient landslide in Songpan County, Sichuan Province, and investigates its geological age and formation mechanism. This study finds that the Gamisi ancient landslide is in the periglacial region of the Minshan Mountain and formed approximately 25 ka BP. The landslide initiation zone has a collapse and slide zone of approximately 22.65×106–31.7×106 m3 and shows a maximum sliding distance of approximately 1.42 km, with an elevation difference of approximately 310 m between the back wall of the landslide and the leading edge of the accumulation area. The landslide movement was characterized by a high speed and long runout. During the sliding process, the landslide body eroded and dammed the ancient Minjiang River valley. The ancient river channel was buried 30-60 m below the surface of the landslide accumulation area. Geophysical prospecting and drilling observations revealed that the ancient riverbed was approximately 80-100 m thick. After the dam broke, the Minjiang River was migrated to the current channel at the leading edge of the landslide. The Gamisi ancient landslide was greatly affected by the regional crustal uplift, topography, geomorphology and paleoclimatic change. The combined action of periglacial karstification and climate change caused the limestone at the rear edge of the landslide fractured, thus providing a lithological foundation for landslide occurrence. Intense tectonic activity along the Minjiang Fault, which runs through the middle and trailing parts of the Gamisi ancient landslide, may have been the main factor inducing landsliding. Studying the Gamisi ancient landslide is of great significance for investigating the regional response to paleoclimatic change and geomorphologic evolution of the Minjiang Fault since the late Pleistocene and for disaster prevention and mitigation.     

澜沧江河流沉积物碎屑锆石U-Pb年龄、Hf同位素组成及其地质意义

为研究澜沧江沉积物的物质来源及相邻地块的地壳生长和演化规律,利用LA-MC-ICP-MS分析技术,对澜沧江河流沉积物碎屑锆石进行了U-Pb年龄和Hf同位素研究。结果表明：锆石U-Pb年龄主要有5个年龄段,分别是＜177 Ma、201~418 Ma、428~544 Ma、581~1189 Ma和1406~2533 Ma,主要峰值为260 Ma、788 Ma、1 827 Ma和2 474 Ma。其年龄分布特征与北羌塘地块的年龄分布非常一致,说明澜沧江沉积物主要来源于北羌塘地块;结合Hf同位素分析结果,能够反映源区北羌塘地块的形成与演化历史。新太古代-中元古代是北羌塘地块从亏损地幔物质增生的地壳持续生长阶段,它们构成现今北羌塘地块全部地壳物质的78%以上,此后直到0.64 Ga,北羌塘地块的地壳增生作用基本结束。     

基于叠前深度偏移的AVO反演在神狐海域试采区的应用

为了更好地研究神狐海域试采区天然气水合物的展布形态和赋存状况,基于高精度层析速度反演后的叠前深度偏移地震资料进行AVO反演技术研究。为在天然气水合物富集区有效地进行AVO研究,AVO处理前运用叠前深度偏移技术,通过高精度层析反演不断迭代速度模型;然后通过偏移来改善资料的质量,结合实测钻井资料进行AVO正演分析、反演可行性分析、属性交会分析;最后将具有高横向分辨能力的地震资料和高垂向分辨能力的测井资料与地质相结合进行叠前同时反演。该方法可反演出纵、横波阻抗等属性,直接进行岩性和流体识别,结果表明,在AVO反演中引入叠前深度偏移技术,为反演提供了较高质量的叠前共反射点道集和精细的层速度模型,改善了AVO技术在试采区的应用效果,提高了反演的可靠性。反演出的各种属性为AVO分析提供了丰富的信息,能够比较准确地反映地下水合物矿体的展布情况,可用于后续水合物储层的分析及综合研究,对未来的水合物勘探开采具有重要的现实意义。     

自吸水分对煤中瓦斯解吸的综合影响

为研究自吸水分对煤中瓦斯解吸的影响,利用自主设计的实验装置,实现了水分在煤中的自发渗吸,单独研究了水分对瓦斯的置换效应,并对不同含水率条件下煤中瓦斯的置换解吸量、卸压解吸量以及残余瓦斯含量进行了测定。结果表明：水分能够促进煤中吸附态瓦斯发生置换解吸,且含水率越大,置换解吸量越大;卸压解吸过程中,相同时间内含水煤样瓦斯解吸量小于干燥煤,且随着含水率升高,解吸量逐渐减小;充分解吸后含水煤样的残余瓦斯含量小于干燥煤,在4%~10%含水率,随着含水率升高,残余瓦斯含量逐渐降低;针对晋城矿区永红煤矿的无烟煤,自吸水分对瓦斯解吸整体上表现为促进作用,水分对瓦斯解吸的影响是置换效应与水锁效应综合作用的结果。     

Rock-magnetic proxies of climate change in the loess-palaeosol sequences of the western Loess Plateau of China

Results of the first detailed study of the climate proxy record in the loess-palaeosol sequence at Xining-one of the few palaeoclimate sites in the currently arid western Loess Plateau of China-illustrate the importance of making many types of rock-magnetic measurements other than susceptibility. A multiparameter approach yielded confirmation that here, as elsewhere in the Loess Plateau, the susceptibility enhancement in palaeosols was caused primarily by ultrafine magnetite and maghaemite. Nevertheless, magnetic enhancement was caused not exclusively by changes in relative grain size, but also by variations in concentration and mineralogy of the magnetic fraction.
The effects of concentration variations were removed through normalization of susceptibility and anhysteretic remanence with saturation magnetization and saturation remanence, respectively. the resulting signal was ascribed more confidently to variation in magnetic grain size, which in turn was interpreted as a better proxy of pedogenesis than simple susceptibility. Variations in magnetic mineralogy were also determined to constrain interpretations further. the data were then used to discuss climate history at Xining. Finally, results from Xining were compared with other western sites and contrasted with eastern sites.
In summary: (1) data is presented from a new Loess Plateau site which also appears to yield a global climate signal; (2) a demonstration is made of a more rock-magnetically robust way to separate concentration, composition and grain-size controls on susceptibility and other magnetic parameters; and (3) models are provided for inter-regional comparisons of palaeoclimate proxy records.     

西安市投资环境优化对策的定量研究

选取系列指标体系，运用层次分析法，采用单排序和总排序，分析比较影响西安市的投资环境的因素系列，确定其权重重要性程度，据此提出优对策。     

A two-dimensional coupled biosphere-atmosphere model and its application

A 2-D zonally averaged, time dependent climate model is developed to study the biosphere-atmosphere interaction. A numerical scheme is specifically designed for the model to ensure the conservation of mass, momentum, energy, and water vapor. A simple parameterization of vegetation-soil layers is incorporated in this 2-D model. Us-ing this coupled model, we study the biosphere and atmosphere interaction. Some preliminary results concerning the African drought with annual mean conditions are presented.     

粮仓温度微机自动监测系统的设计研究

本文介绍了作者研制CW—1型微机测温系统的设计方法,着重介绍了在提高测温精度和联网通信方面采取的技术关键。