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1.
Geography is a product of colonial processes, and in Canada, the exclusion from educational curricula of Indigenous worldviews and their lived realities has produced “geographies of ignorance”. Transformative learning is an approach geographers can use to initiate changes in non-Indigenous student attitudes about Indigenous epistemologies and ontologies. This study explores non-Indigenous student perspectives concerning a field school and digital storytelling as transformative experiences within the context of an “Indigenous Perspectives on Environmental Management” course; they were asked to reflect on their course experience. Findings indicate that students found both to be effective and important steps in the transformation of their own worldviews.  相似文献   

2.
D. BROSETA  N. TONNET  V. SHAH 《Geofluids》2012,12(4):280-294
The various modes of acid gas storage in aquifers, namely structural, residual, and local capillary trapping, are effective only if the rock remains water‐wet. This paper reports an evaluation, by means of the captive‐bubble method, of the water‐wet character in presence of dense acid gases (CO2, H2S) of typical rock‐forming minerals such as mica, quartz, calcite, and of a carbonate‐rich rock sampled from the caprock of a CO2 storage reservoir in the South‐West of France. The method, which is improved from that previously implemented with similar systems by Chiquet et al. (Geofluids 2007; 7 : 112), allows the advancing and receding contact angles, as well as the adhesion behavior of the acid gas on the mineral substrate, to be evaluated over a large range of temperatures (up to 140°C), pressures (up to 150 bar), and brine salinities (up to NaCl saturation) representative of various geological storage conditions. The water‐receding (or gas‐advancing) angle that controls structural and local capillary trapping is observed to be not significantly altered in the presence of dense CO2 or H2S. In contrast, some alteration of the water‐advancing (or gas‐receding) angle involved in residual trapping is observed, along with acid gas adhesion, particularly on mica. A spectacular wettability reversal is even observed with mica and liquid H2S. These results complement other recent observations on similar systems and present analogies with the wetting behavior of crude oil/brine/mineral systems, which has been thoroughly studied over the past decades. An insight is given into the interfacial forces that govern wettability in acid gas‐bearing aquifers, and the consequences for acid gas geological storage are discussed along with open questions for future work.  相似文献   

3.
ENVIRONMENTAL AND EVOLUTIONARY ECONOMIC GEOGRAPHY: TIME FOR EEG2?   总被引:1,自引:0,他引:1  
This article argues that recent proposals for environmental and evolutionary economic geographies (EEG 1 and EEG2) should be integrated; EEG2 is used as “passing convenience” to make this case. EEG1's emphasis on environmental imperatives is loosely framed and needs a theoretical socio‐economic evolutionary base that is the central thrust of EEG2. Meanwhile EEG2 would be empowered by incorporating environmental concerns within its mandate. Moreover, both EEG1 and EEG2 share common roots in institutional methodologies, emphasize cumulative causation and path‐dependent behaviour, have strong interests at regional scales of analysis, and both are intimately tied to the causes and consequences of innovation. This article provides a rationale and suggests an integrative conceptual approach for developing EEG2. In particular, the article outlines a conceptual framework that interprets EEG2 in terms of co‐evolutionary socio‐ecological and multi‐scalar processes that are situated within a reasoned history interpretation of economic development. This framework further highlights the roles of path dependency, innovation, multinational corporations and value chains. How this multi‐scalar framework may be elaborated is then discussed around three themes: extending placed‐based analysis of localized clusters; broadening the scope of global value chain analysis; and re‐engaging the analysis of core–periphery relations. Ultimately the case for EEG2 is to ensure that economic geographic perspectives are fully incorporated in debates over the co‐evolution of economy and environment, in research and policy terms one of, if not the, central challenges of development in the 21st century.  相似文献   

4.
Numerical simulations of multiphase CO2 behavior within faulted sandstone reservoirs examine the impact of fractures and faults on CO2 migration in potential subsurface injection systems. In southeastern Utah, some natural CO2 reservoirs are breached and CO2‐charged water flows to the surface along permeable damage zones adjacent to faults; in other sites, faulted sandstones form barriers to flow and large CO2‐filled reservoirs result. These end‐members serve as the guides for our modeling, both at sites where nature offers ‘successful’ storage and at sites where leakage has occurred. We consider two end‐member fault types: low‐permeability faults dominated by deformation‐band networks and high‐permeability faults dominated by fracture networks in damage zones adjacent to clay‐rich gouge. Equivalent permeability (k) values for the fault zones can range from <10?14 m2 for deformation‐band‐dominated faults to >10?12 m2 for fracture‐dominated faults regardless of the permeability of unfaulted sandstone. Water–CO2 fluid‐flow simulations model the injection of CO2 into high‐k sandstone (5 × 10?13 m2) with low‐k (5 × 10?17 m2) or high‐k (5 × 10?12 m2) fault zones that correspond to deformation‐band‐ or fracture‐dominated faults, respectively. After 500 days, CO2 rises to produce an inverted cone of free and dissolved CO2 that spreads laterally away from the injection well. Free CO2 fills no more than 41% of the pore space behind the advancing CO2 front, where dissolved CO2 is at or near geochemical saturation. The low‐k fault zone exerts the greatest impact on the shape of the advancing CO2 front and restricts the bulk of the dissolved and free CO2 to the region upstream of the fault barrier. In the high‐k aquifer, the high‐k fault zone exerts a small influence on the shape of the advancing CO2 front. We also model stacked reservoir seal pairs, and the fracture‐dominated fault acts as a vertical bypass, allowing upward movement of CO2 into overlying strata. High‐permeability fault zones are important pathways for CO2 to bypass unfaulted sandstone, which leads to reduce sequestration efficiency. Aquifer compartmentalization by low‐permeability fault barriers leads to improved storativity because the barriers restrict lateral CO2 migration and maximize the volume and pressure of CO2 that might be emplaced in each fault‐bound compartment. As much as a 3.5‐MPa pressure increase may develop in the injected reservoir in this model domain, which under certain conditions may lead to pressures close to the fracture pressure of the top seal.  相似文献   

5.
Eastern Sicily (southern Italy) is characterised by the presence of many natural gas emissions (mofettes, mud volcanoes). These gases are mostly carbon dioxide and methane, with minor amounts of helium, hydrogen, carbon monoxide and hydrocarbons. In this study, the extent and orientation of soil gas anomalies (He and CO2) were investigated on a wide area (approximately 110 km2) located just SW of Mt. Etna. From a structural point of view, this area lays on a typical foredeep–foreland system that marks the boundary between the southern part of the Eurasian plate and the northern part of the African plate in the central Mediterranean. No tectonic structure was revealed in this area by surface geological surveys. Very high soil emissions were found, and their spatial pattern reveals the existence of some active faults all directed about N50°E. This direction coincides with that of two major fault systems that cut eastern Sicily and are evident, respectively, NE and SW of the study area. Soil gas data suggest that these fault systems are the expression of a single continuous structural line which is probably responsible for the past and present magma uprise in eastern Sicily. Isotopic values of carbon of CO2 suggest a minor contribution of organic carbon. Moreover, in the highest degassing sites the isotopic values of He found in association with CO2 (He abundance = 11–70 p.p.m.; R/Ra between 6.0 and 6.2) suggest that both gases are mantle derived. The extent of the areas affected by high gas emissions and the amounts of deep CO2 emitted in the investigated area (several hundred tonnes per day) may provide additional supporting evidence of a mantle upwelling taking place beneath this region.  相似文献   

6.
Smoky fires in small, poorly ventilated structures have been cited as a risk factor for nasopharyngeal carcinoma (NPC) since the 1920s (Dobson, 1924 ). Furthermore, based on five cited cases of ancient NPC, it has been proposed that NPC was a common condition with a wide geographical distribution in ancient populations (Wells, 1964a , b ). Both interpretations have continued to appear in the literature (Ortner, 2003 ), but recently, Aufderheide & Rodríguez‐Martín ( 1998 ) have argued that the number of cases of NPC is inflated due to ‘diagnostic imprecision’. This paper reviews medical advances that in the last few decades have shed considerable light on risk factors for NPC, and also reviews criteria for diagnosing NPC. Based on these data, a reexamination of the five cited cases of ancient NPC suggests that only one case may be NPC, and the prevalence and distribution of this disease may have been more variable than originally thought. Furthermore, a better understanding of the aetiology of NPC and criteria for diagnosis may allow for more precise research designs for studying ancient populations. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

7.
A geochemical study was carried out on the CO2‐rich water occurring in granite areas of Chungcheong Province, Korea. In this area, very dilute and acidic CO2‐rich waters [62–242 mg l?1 in total dissolved solid (TDS), 4.0–5.3 in pH; group I) occur together with normal CO2‐rich waters (317–988 mg l?1 in TDS, 5.5–6.0 in pH; group II). The concentration levels and ages of group I water are similar to those of recently recharged and low‐mineralized groundwater (group III). Calculation of reaction pathways suggests that group I waters are produced by direct influx of CO2 gas into group III type waters. When the groundwater is injected with CO2, it develops the capacity to accept dissolved solids and it can evolve into water with very high solute concentrations. Whether the water is open or closed to the CO2 gases becomes less important in controlling the reaction pathway of the CO2‐rich groundwater when the initial pco 2 is high. Our data show that most of the solutes are dissolved in the CO2‐rich groundwater at pH > 5 where the weathering rates of silicates are very slow or independent of pH. Thus, groundwater age is likely more important in developing high solute concentrations in the CO2‐rich groundwaters than accelerated weathering kinetics because of acidic pH caused by high pco 2.  相似文献   

8.
9.
将高斯两步移动搜索方法引入到就业可达性测度研究中,在证明方法有效性的同时,也对研究案例沈阳市中心城区的就业可达性空间格局、形成机理进行了分析,并提出相应的调控策略。结果显示,沈阳市中心城区的就业可达性在空间上并非均匀分布,而是呈现为明显的中心-外围格局。形成这一格局的机理有:①单中心的城市形态;②城市规划的功能性布局;③居住的郊区化;④旧城改造与政策性住房;⑤地理要素的空间阻隔。提出用足规划手段促进产业与人口均衡化布局、旧城改造与政策性住房的合理落位、完善城市交通,破除路径障碍与培育多中心城市空间结构等调控策略。  相似文献   

10.
银器文物的变色原因及防变色缓蚀剂的筛选   总被引:5,自引:2,他引:3  
为探讨银器物变色的原因与防变色缓蚀剂的筛选研究,用极化曲线法对目前已知的多个银缓蚀剂进行缓蚀性能评价。筛选出较优良的银缓蚀剂为:2-巯基苯并恶唑(MBO)、1-苯基-5-巯基四氮唑(PMTA)、2-巯基苯并咪唑(MBI)等。这对银器物保护有较大的实用价值。  相似文献   

11.
H. Chu  G. Chi  I‐M. Chou 《Geofluids》2016,16(3):518-532
Fluid inclusions of the H2O‐NaCl‐CaCl2 system are notorious for their metastable behavior during cooling and heating processes, which can render microthermometric measurement impossible or difficult and interpretation of the results ambiguous. This study addresses these problems through detailed microscopic examination of synthetic solutions during cooling and warming runs, development of methods to enhance nucleation of hydrates, and comparison of microthermometric results with different degrees of metastability with values predicted for stable conditions. Synthetic H2O‐NaCl‐CaCl2 solutions with different NaCl/(NaCl + CaCl2) ratios were prepared and loaded in fused silica capillaries and glass‐sandwiched films for microthermometric studies; pure solutions were used with the capillaries to simulate fluid inclusions, whereas alumina powder was added in the solutions to facilitate ice and hydrate crystallization in the sandwiched samples. The phase changes observed and the microthermometric data obtained in this study have led to the following conclusions that have important implications for fluid inclusion studies: (i) most H2O‐NaCl‐CaCl2 inclusions that appear to be completely frozen in the first cooling run to ?185°C actually contain large amounts of residual solution, as also reported in some previous studies; (ii) inability of H2O‐NaCl‐CaCl2 inclusions to freeze completely may be related to their composition (low NaCl/(NaCl + CaCl2) ratios) and lack of solid particles; (iii) crystallization of hydrates, which is important for cryogenic Raman spectroscopic studies of fluid inclusion composition, can be greatly enhanced by finding an optimum combination of cooling and warming rates and temperatures; and (iv) even if an inclusion is not completely frozen, the melting temperatures of hydrohalite and ice are still valid for estimating the fluid composition.  相似文献   

12.
Geologic carbon capture and storage (CCS) is an option for reducing CO2 emissions, but leakage to the surface is a risk factor. Natural CO2 reservoirs that erupt from abandoned oil and gas holes leak to the surface as spectacular cold geysers in the Colorado Plateau, United States. A better understanding of the mechanisms of CO2‐driven cold‐water geysers will provide valuable insight about the potential modes of leakage from engineered CCS sites. A notable example of a CO2‐driven cold‐water geyser is Crystal Geyser in central Utah. We investigated the fluid mechanics of this regularly erupting geyser by instrumenting its conduit with sensors and measuring pressure and temperature every 20 sec over a period of 17 days. Analyses of these measurements suggest that the timescale of a single‐eruption cycle is composed of four successive eruption types with two recharge periods ranging from 30 to 40 h. Current eruption patterns exhibit a bimodal distribution, but these patterns evolved during past 80 years. The field observation suggests that the geyser's eruptions are regular and predictable and reflect pressure and temperature changes resulting from Joule–Thomson cooling and endothermic CO2 exsolution. The eruption interval between multiple small‐scale eruptions is a direct indicator of the subsequent large‐scale eruption.  相似文献   

13.
采用可变步长的两步移动搜索法,以福建省福州市为典型案例,以居民点(普查小区)为分析单元,对各居民点入园空间可达性进行了测算,并与传统的两步移动搜索法进行对比分析,综合判别学前教育资源空间分布特点。研究表明:福州城区入园可达性总体情况并不理想,仅有少数地区、少量人群可以获得较好的幼儿园空间的可达性。入园可达性在地理空间上呈现出多中心结构,高可达性地区主要分布在市中心并在城市周围零星分布,边缘乡镇特别是除西部以外的乡镇地区缺教明显,入园可达性在城区内部差异较大,幼儿园资源过剩地区和稀缺地区呈两极分化的格局。可变步长的两步移动搜索法能更为客观有效地对幼儿园的布局状况进行评价。而传统方法有一定的夸大作用,且降低了内部的差异,在一定程度上掩饰了幼儿园资源分布的不公平现象。  相似文献   

14.
Scholars have identified a hiatus in the archaeological record of Lower Nubia that spans approximately 1000 years. This interval may represent a desertion of Lower Nubia by its inhabitants. Evidence of occupation did not reappear in the area until the Meroitic time period. However, the identity of the returning people has been the subject of speculation. In order to determine who the Meroites of Lower Nubia were, 20 cranial non‐metric traits were observed on six Nubian groups, representing five time periods. Two groups date to time periods immediately before (Kerma) and immediately after (X‐Group) the Meroitic period. Three additional Nubian groups (two Christian samples from different sites and Sesebi, a contemporary sample) were utilised as outgroups to elucidate a clearer picture of the relationship among the six samples. Mahalanobis D2 with a tetrachoric matrix was employed for calculating biological distances among the groups. Principal coordinates analysis produced two clusters of Nubians, where the Meroitics clustered with other Nubian groups. Specific distance scores indicate the Meroites were biologically similar to individuals from the time periods prior to and after their arrival in Lower Nubia. The Meroites therefore appear to be a Nubian group returning to Lower Nubia after its desertion. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

15.
为了检测保存液pH值和Ca2 浓度对古尸骨组织脱钙的影响,本实验于2002年检测了古尸保存液的pH值和微量元素含量,然后分两步调整了马王堆古尸保存液的pH值和Ca2 浓度,并分别于2004年、2006年进行了相同检测。结果发现适当上调保存液的pH值和Ca2 浓度能明显延缓古尸保存液中Ca2 浓度的增加:而保持适当的pH值、适当降低Ca2 浓度明显加速了古尸保存液中Ca2 浓度的增加。这些表明保存液pH值和Ca2 浓度的适当提高有利于防止古尸骨组织的脱钙。  相似文献   

16.
17.
山东危山西汉墓出土陶器彩绘颜料研究   总被引:6,自引:4,他引:2  
为研究山东危山西汉墓出土彩绘陶器颜料成分,采用偏光显微镜、显微拉曼光谱仪和扫描电子显微镜-能谱仪进行了分析。研究结果显示,危山汉墓陶器彩绘颜料有朱砂、铅丹、中国紫(汉紫BaCuSi2O6)、铁红、铁黑、白土等。中国紫颜料首次在山东省的发现,扩大了该颜料的使用区域,具有重要的考古学意义。另外,还在紫色颜料中分析出了BaCu2Si2O7蓝色晶体,这是继中国蓝中国紫之后的又一重大发现。  相似文献   

18.
While Sunnism is the largest sect of Islam, Sunnism itself is divided into many strands. The two main strands of Sunnism for the last few centuries are the Atharī (or Salafī) strand, and the Ash?arī strand. This papers seeks to examine the earliest recorded controversies that signal this intra‐Sunnī divide. While each of these two groups has historically attempted to claim true Sunnī ‘orthodoxy’ by denying the legitimacy, and at times even the early existence, of the other, it will be shown that the genesis of this intra‐Sunnī divide dates back to the first century of Sunnism itself, viz., the 3rd AH/8th CE centuries, and that there are specific historic incidents that indicate theological tensions within the nascent Sunnī movement that would later be manifested in the two streams of Ash?arism and Salafism. Hence, it can be argued that Sunnism was never truly unified to begin with, and that these incidents demonstrate theological tensions that existed from its very origins.  相似文献   

19.
This study focused on the spatial evolution of COVID-19 in the state of Chihuahua, Mexico. Data were retrieved from governmental databases and analyzed by means of GIS, applying the inverse distance weighted (IDW) method. The period of December 2019 through November 2021 was split into eight seasons. The root mean square error (RMSE) was used to assess the reliability of the interpolations, showing acceptable values (RSME < 25). During the period, the municipalities of Juarez and Chihuahua reached the highest number of confirmed cases and deaths, Juarez being the main hotspot of contagion (37.2% of confirmed cases; 46.9% of deaths). Four waves of contagion were identified during the evaluated period, with Fall 2020 being the strongest season. Since Fall 2020, the spread of the disease was more often observed in municipalities with the highest human mobility. Although the spread of COVID-19 decreased after Spring 2021, in Fall 2021 records indicated a continuous increase in cases in the state. That could be due to a relaxation of the implementation of sanitary measures, as well as to the propagation of novel COVID-19 variants having an elevated infectious level. Geospatial techniques allowed for an understanding of the spatial spread of COVID-19 and could be useful for its control.  相似文献   

20.
The Central Apennines are affected by frequent earthquakes of moderate magnitude that occur mainly within the upper part of the crust at depths of <15 km. A large number of cold gas emissions that are rich in CO2 are also found in the region. One particular vent with a high rate of degassing was equipped with a sensor to measure flow rates, which were recorded for a number of different periods between 2005 and 2010. Factors that could affect potentially CO2 flow rates include barometric pressure, atmospheric temperature, precipitation and local seismicity. Our analysis indicates that the periods of anomalous flow rate were related not to the environmental factors but probably to the deformative processes of the crust associated with the local seismicity. Local seismic events as expression of geodynamic processes occurred always before and during these anomalous gas flow periods. This correlation exists only for events that occurred eastwards of the gas emission site close to the Martana fault zone. We herein consider this correlation as indication for a continuous interaction between the field of static strain and the deep fluid pressure. An approximation of the fluid pressure transmission towards the gas emission site gives reasonable values of 1–10 m2 sec?1. To make comparisons with the long‐term effects of the static strain, we also recorded the short‐term effects of the dynamic release of strain induced by the series of strong earthquakes that took place in L’Aquila in 2009. We detected a significant anomalous flow rate that occurred at the same time as this seismic sequence, during which widespread degassing was induced around the focal zone.  相似文献   

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