ABSTRACT A growing mass of research contributes to our understanding of how biological and cultural diversity are related in complex and important ways. This paper presents an assembling process of biodiversity and cultural diversity on an island, Kin‐men (Quemoy), based on 1600 years of its environmental history. The study shows that the island's biocultural assemblages are a result both of external relations with the island's surrounding environment and internal relations within the island's changing human ecology. Distant political powers and economic forces are the two major external influences that have affected the flow of natural and cultural elements to and from the island, while ‘screening effects’ and ‘isolation effects’ are two factors that explain internal interactions. The island's biocultural assembling processes reveal that the openness of the island facilitates increase in the diversity of biocultural elements, while its less disturbed isolated condition fosters natural succession and co‐evolution. The study suggests that biocultural assemblages and the associated processes of co‐evolution and nature–society interactions are accomplished through the intermittent opportunities purposively provided by or inadvertently found in the openings and closures of boundaries, setting the scene for both boundary crossings and bounded shelter, by intent or chance. 相似文献
Capillary trapping is a physical mechanism by which carbon dioxide (CO2) is naturally immobilized in the pore spaces of aquifer rocks during geologic carbon sequestration operations, and thus a key aspect of estimating geologic storage potential. Here, we studied capillary trapping of supercritical carbon dioxide (scCO2), and the effect of initial scCO2 saturation and flow rate on the storage/trapping potential of Berea sandstone. We performed two‐phase, scCO2‐brine displacements in two samples, each subject to four sequential drainage–imbibition core‐flooding cycles to quantify end‐point saturations of scCO2 with the aid of micro‐ and macro‐computed tomography imaging. From these experiments, we found that between 51% and 75% of the initial CO2 injected can be left behind after the brine injection. We also observed that the initial scCO2 saturation influenced the residual scCO2 saturation to a greater extent than the rate of brine injection under the experimental conditions examined. In spite of differences in the experimental conditions tested, as well as those reported in the literature, initial and residual saturations were found to follow a consistent relationship. 相似文献
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 (kabs) of the samples was determined by steady state flow tests with water or NaCl brine. The kabs values ranged between 3 and 550 nDarcy (3 × 10?21 and 5.5 × 10?19 m2). The maximum effective permeability to the gas‐phase (keff) 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’ (Pd), 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. 相似文献
To thermally upgrade exterior masonry walls, interior insulation is often the only possible retrofitting technique, especially when dealing with historic buildings. Unfortunately, it is also the riskiest post-insulation technique, as frost damage, interstitial condensation, and other damage patterns might be induced. To diminish those risks, nowadays so-called capillary active interior insulation systems are often promoted. These systems aim a minimal reduction of the inward drying potential, while interstitial condensation is buffered.
Currently, several capillary active systems are on sale. These different types have, however, widely varying properties. In this article, a closer look at the hygrothermal properties and the working principle of a number of “capillary active” interior insulation systems is made. The spread in capillary absorption coefficients and the vapor diffusion resistances of the different systems is discussed and their influence is illustrated. Based on all this, a more nuanced view on capillary active insulation systems is pursued.
Accurate reconstruction of diagenetic P‐T conditions in petroleum reservoirs from fluid inclusion data relies on valid measurements of methane concentration in aqueous inclusions. Techniques have been developed (Raman spectrometry) to provide sufficiently accurate data, assuming measured methane concentration has not been modified after aqueous inclusion entrapment. This study investigates the likelihood that organic acids derived from petroleum fluids and dissolved in formation water might suffer decarboxylation upon postentrapment heating within the fluid inclusion chamber, thereby generating excess CH4 in the inclusions. Four different experiments were conducted in fused silica capillary capsules (FSCCs), mimicking fluid inclusions. The capsules were loaded with acetic (CH3COOH) or formic (HCOOH) acid solution and were heated to 250°C for short durations (<72 h) in closed‐system conditions, with or without applying a fixed PH2. Reaction products were characterized by Raman and FT‐IR spectrometry. Results indicate that decarboxylation reactions did take place, at variable degrees of progress, and that measurable excess CH4 was produced in one experiment using acetic acid. This suggests that methane may be produced from dissolved organic acids in natural aqueous inclusions in specific situations, possibly inducing errors in the thermodynamic interpretation. 相似文献
The British engagement with Oman from 1967–76 came at a time when other imperial and defence commitments were being reduced in the Gulf region and elsewhere. Following the ignominious retreat from Aden, the British chose to support the Omani regime in its conflict with Communist-inspired insurgents (1970–6). This article gives context to the dichotomy of outcomes in southern Arabia and examines the role of local military forces in the counter-insurgencies. It demonstrates that Britain's domestic political considerations, regional strategic requirements, and concerns for its global reputation, rather than counterinsurgency operations and the local forces, were the main drivers of outcomes. Insurgents and local actors nevertheless responded to changes taking place in and around Oman, recalibrating their decision to co-operate or resist on their own terms, and changes in the international support for the insurgents were decisive. The key argument is that the dynamic combinations of international support, British strategic assumptions and miscalculations, and local agency, were crucially important to the outcomes in the region. The ‘fate’ of those who had allied with, or resisted, the British, needs to be set in this context. 相似文献