Gas breakthrough experiments on fine-grained sedimentary rocks

The capillary sealing efficiency of fine‐grained sedimentary rocks has been investigated by gas breakthrough experiments on fully water saturated claystones and siltstones (Boom Clay from Belgium, Opalinus Clay from Switzerland and Tertiary mudstone from offshore Norway) of different lithological compositions. Sand contents of the samples were consistently below 12%, major clay minerals were illite and smectite. Porosities determined by mercury injection lay between 10 and 30% while specific surface areas determined by nitrogen adsorption (BET method) ranged from 20 to 48 m² g ^{? 1}. Total organic carbon contents were below 2%. Prior to the gas breakthrough experiments the absolute (single phase) permeability (k_abs) of the samples was determined by steady state flow tests with water or NaCl brine. The k_abs values ranged between 3 and 550 nDarcy (3 × 10^?21 and 5.5 × 10^?19 m²). The maximum effective permeability to the gas‐phase (k_eff) measured after gas breakthrough on initially water‐saturated samples extended from 0.01 nDarcy (1 × 10^?23 m²) up to 1100 nDarcy (1.1 × 10^?18 m²). The residual differential pressures after re‐imbibition of the water phase, referred to as the ‘minimum capillary displacement pressures’ (P_d), ranged from 0.06 to 6.7 MPa. During the re‐imbibition process the effective permeability to the gas phase decreases with decreasing differential pressure. The recorded permeability/pressure data were used to derive the pore size distribution (mostly between 8 and 60 nm) and the transport porosity of the conducting pore system (10^‐5–10^‐2%). Correlations could be established between (i) absolute permeability coefficients and the maximum effective permeability coefficients and (ii) effective or absolute permeability coefficients and capillary sealing efficiency. No correlation was found between the capillary displacement pressures determined from gas breakthrough experiments and those derived theoretically by mercury injection.     

Equations of state for basin geofluids: algorithm review and intercomparison for brines

Physical properties of formation waters in sedimentary basins can vary by more than 25% for density and by one order of magnitude for viscosity. Density differences may enhance or retard flow driven by other mechanisms and can initiate buoyancy‐driven flow. For a given driving force, the flow rate and injectivity depend on viscosity and permeability. Thus, variations in the density and viscosity of formation waters may have or had a significant effect on the flow pattern in a sedimentary basin, with consequences for various basin processes. Therefore, it is critical to correctly estimate water properties at formation conditions for proper representation and interpretation of present flow systems, and for numerical simulations of basin evolution, hydrocarbon migration, ore genesis, and fate of injected fluids in sedimentary basins. Algorithms published over the years to calculate water density and viscosity as a function of temperature, pressure and salinity are based on empirical fitting of laboratory‐measured properties of predominantly NaCl solutions, but also field brines. A review and comparison of various algorithms are presented here, both in terms of applicability range and estimates of density and viscosity. The paucity of measured formation‐water properties at in situ conditions hinders a definitive conclusion regarding the validity of any of these algorithms. However, the comparison indicates the versatility of the various algorithms in various ranges of conditions found in sedimentary basins. The applicability of these algorithms to the density of formation waters in the Alberta Basin is also examined using a high‐quality database of 4854 water analyses. Consideration is also given to the percentage of cations that are heavier than Na in the waters.     

Archaeological Heritage in Guatemala: Indigenous Perspectives on the Ruins of Iximche’

In Guatemala local perspectives on heritage often remain unheard. In this paper a case study is presented to show the complex relationship between the highland site of Iximche’ and Tecpán, an Indigenous community nearby. Although Iximche’ is of little importance to the local economy, its significance is derived from its role as a field for different kinds of social and religious interactions. Traces of a spiritual relationship to this place can be dated back to the colonial period and today Maya from all over Guatemala go there to perform ceremonies. The place has also become a focal point of identity constructions for locals, Pan Mayan activists and the nation itself. The ruins of Iximche’ play an important role in the construction of collective memory which also includes ideas coming from external players such as Christian churches, the national government, Mayan activists, and archaeologists as well.     

A Nation‐state without the nation? The trajectories of nation‐formation in Montenegro1

ABSTRACT. Following the successful referendum of May 2006, Montenegro became the last of the former Yugoslav republics to opt for an independent state. Only fifteen years earlier, when the Socialist Federal Republic of Yugoslavia collapsed, Montenegro was resolute to continue the Yugoslav state‐formation in a union with Serbia. This paper attempts to answer the following questions: Why did it take so much longer for the Montenegrin population to follow the experience of other republics in its decision on independence? How can one explain a staggering change in public opinion on questions of national self‐determination over such a short time‐span? And, finally, what are the dominant discourses of “Montenegrin‐ness”? The authors argue that the answers to these questions are to be found in the particularities of Montenegro's historical development, and especially in the structural legacies of state socialism. The consequence of these developments was the formation of two separate Montenegrin national ideologies: one which sees Montenegrins as ethnically Serb, and the other that defines Montenegrins in civic terms. The paper concludes that these two divergent trajectories of nation‐formation in Montenegro are largely the unintended consequence of intensive state‐building, cultural and political modernisation and, most of all, the gradual politicisation and institutionalisation of high culture.     

中国文化自然遗产管理评价的指标体系初探

化和自然遗产管理的研究引起学术界重视。目前献集中于研究转型期遗产管理的组织结构的调整,但缺少在管理机制的设计和操作层面上开展研究。本试图从遗产管理绩效评估入手开始对遗产管理激励机制的探索。初步构建了以遗产保护为基本目标和以社区发展、游客管理和经营开发为贡献目标的遗产管理评价指标体系,并对评价的原则和关键指标确定等进行思考。     

试论夏商城市水利设施及其功能

本文就考古所见夏商城址内的水利遗存进行了分析,对夏商城市水利设施的种类、功能、渊源等相关问题进行了初步探讨。     

改革开放以来小康社会理论的形成与发展

小康社会理论是中国特色社会主义理论体系的主体组成部分之一,是马克思主义现代化理论与中国发展实际相结合的产物,丰富和发展了对中国特色社会主义现代化过程的理解。在1980年代由邓小平提出,经历了六个发展阶段,到中共十七大提出＂全面建设小康社会新要求＂之际,完全成熟。由＂大同论＂向＂小康论＂转型,有其深刻的现实、历史、理论与文化的根源。＂小康论＂立足于社会主义初级阶段的基本国情,以社会化大生产与工业市场文明为目标诉求,在强调公有制的主导作用下,显示出对个人利益的认可、宽容与疏导,强调＂法治＂、＂市场＂＂、共同富裕＂与＂民主＂。注重循序渐进而不急于求成。小康社会理论的形成与发展,是对中国特色社会主义现代化理论的创新。     

日本古代天皇制的形成及其政治结构刍议

日本古代天皇制的形成,启动于圣德太子改革,初步形成（模型化）于孝德天皇与天智天皇的大化改新时期,制度化于大化改新矛盾积累导致的“壬申之乱”后的天武天皇及其继任者持统、文武、元明天皇时期,中间走过了百年左右的曲折历程。圣德太子改革、大化改新、“壬申之乱”是日本古代天皇制形成的三部曲。从政治结构上看,古代天皇制具有明显的日本特色,它是中国式皇帝制与日本祭祀制的统一。古代天皇制特殊的政治结构对后来的日本政治文化传统产生了深远影响。     

江苏连云港将军崖旧石器晚期遗址的考古发掘与收获

2002～2006年在连云港将军崖旧石器晚期遗址的发掘,主要收获包括人类石铺生活面1处和可能属于灶坑的遗迹2处,以及1500余件石制品。工具类型以刮削器为主,以小型为主,石片石器和细石器各占一定比例。石器工业早期为华北主工业类型——石片石器工业,晚期以细石器为主。主要文化层的地质年代为晚更新世晚期至全新世早期。     

"中国"与"天下"的重合——古代中国疆域形成的历史轨迹

“The Central Kingdom” is pregnant of political implications as well as of geographical and cultural significance. It was believed that whoever controlled Zhongguo (the Central Kingdom or China) would be the legitimate ruler over Tianxia (the realm under heaven or all under heaven). It was the contention for “the Central Kingdom” among the varieties of dynasties, notably those established by the Han-Chinese and the various ethnic groups in the northern borderland, that lead to the alternation of disintegration and unification of the territory. It was not until the Qing Dynasty that the unified “Central Kingdom” composed of a variety of ethnic groups turned into the ideal “realm under heaven” with “the Central Kingdom” at its core, which naturally put an end to the formation of territory in ancient China. Translated by Chen Dan from Zhongguo Bianjiang Shidi Yanjiu 中国边疆史地研究 (China’s Borderland History and Geography Studies), 2007, (3): 1–15