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161.
162.
Arthur P.J. Mol 《Singapore journal of tropical geography》2009,30(1):114-129
In the field of environmental governance information is starting to become increasingly important, not least because of globalization and the information and communication technologies revolution. The notion of informational governance is a recent coinage that acknowledges the (partial) switch from regulatory‐based forms of governance to information‐based modes. In the information‐rich centres and nodes of the network society, where information is widely produced, disseminated and accessible, this might prove analytically useful. But what are the contours of informational governance in information‐poor environments? This paper looks into the (limited) emergence of informational governance arrangements in environmental protection in two cases characterizing the informational periphery: China and Vietnam. 相似文献
163.
Geological sequestration is one of the most effective ways to reduce greenhouse gases, such as carbon dioxide (CO2). The deep oceanic crust dominated by ultrabasic rock could store CO2 permanently. However, the storage mechanism has not been thoroughly understood because of the limited amount of research and experiments conducted. This study explored the reactive mechanisms of water–rock–gas in an ultrabasic system under different conditions. Forsterite, the most dominant mineral found in ultrabasic reservoirs, was used to conduct laboratory physical simulation experiments. Two experimental systems were designed including an scCO2–forsterite–water system and an N2–forsterite–water system. All experiments were performed for 1000 h at an experimental temperature of 150°C and a pressure of 150 bar, respectively, to mimic the geological conditions. The liquid products from the experiments were analysed by inductively coupled plasma-optical emission spectrometry, whereas the solid samples were analysed by scanning electron microscopy with energy disperse spectroscopy. Results showed that: (1) in the early stage during scCO2/N2–forsterite–water interaction, forsterite was dissolved with a reactive transitional zone forming on the surface, which caused H+ to enter into the silicate framework and accelerated the reaction; (2) in the N2 system, the dissolution of forsterite was inhibited by the Mg2+ concentration after reaching its saturation in the late stage; and (3) in the scCO2 system, magnesite was precipitated as a secondary mineral during the late stage, which promoted the dissolution of forsterite. As a result, the degree of dissolution of forsterite in the scCO2 system was far higher than in the N2 system. The experimental results are consistent with the numerical simulation using TOUGHREACT, a geochemical simulation procedure, which showed that CO2 promotes the dissolution of forsterite greatly at high temperature and pressure. 相似文献
164.
毛乌素地区农业用地方式转换与沙漠化 总被引:1,自引:0,他引:1
Introduction and the study area Desertification refers to land degradation phenomenon and process in arid, semi-arid and dry sub-humid areas (the humid index between 0.05 and 0.65) resulting from various factors, including climatic variations and human ac… 相似文献
165.
应变速率与单轴压缩强度极值的关系在抗冰结构设计与优化中占有重要地位。基于2009年冬季普兰店海域海冰在不同海冰温度(-5°C、-10°C、-15°C)下的压缩强度试验数据,给出各自应变速率—压缩强度散点图。结果表明,海冰在不同加载速率下表现为三种破坏模式,即韧性区、过渡区与脆性区;海冰温度对过渡区对应应变速率范围影响较小,均在6.3×10~(-4)~2×10~(-3)区域附近。结合三段式函数形式,给出不同温度下应变速率—压缩强度极值的曲线拟合结果。依据上述结论,在庄河海域选择应变速率10~(-2)、10~(-3)与10~(-4)进行不同海冰温度(-16°C~-4°C)下单轴压缩强度试验。结果显示:在韧性区,海冰温度与压缩强度极值呈弱负相关;在过渡区,海冰温度与压缩强度极值呈明显线性减小;在脆性区,强度极值相对海冰温度敏感度较低。基于此,在应变速率—压缩强度曲线中提出温度影响系数,这一试验分析方法可推广至其它海域。 相似文献
166.
Marcella Leonardi Filippo Azzaro Maurizio Azzaro Gabriella Caruso Monique Mancuso Luis Salvador Monticelli Giovana Maimone Rosabruna La Ferla Francesco Raffa & Renata Zaccone 《Marine Ecology》2009,30(S1):33-42
In the framework of the VECTOR DIVCOST Project, a 2-year investigation was started in 2006, with the aim of testing the sensibility of microbial parameters to environmental changes and of assessing whether they can provide information about functional changes in the carbon cycle. The investigation was performed in the surface waters of two small brackish ponds (Ganzirri and Faro), located in the Cape Peloro transitional area (Sicily, Italy). The seasonal changes in both the microbial compartment [bacterioplankton, vibrios, exoenzymatic hydrolysis of proteins and polysaccharides, bacterial secondary production (HBP) and community respiration] and the trophic state of suspended matter [total suspended matter (TSM), particulate organic carbon (POC), particulate organic nitrogen (PON), C/N] were analysed in relation to the hydrological characteristics [temperature, salinity, oxygen, fluorescence, NH4 , NO2 , NO3 , PO4 ]. Despite marked differences in the nutritional input and the diversification in both carbon budget and trophic level, the two ponds show similar trends in many of the investigated factors, hardly influenced by seasonal variations. Temporally coupled trends were observed for some parameters (enzyme activities, vibrios abundances, respiratory activity), whereas others (POC, PON, heterotrophic bacterial production, bacterioplankton) showed a seasonal shift between the two lakes. The different behaviour found for the some biotic parameters suggests that their response to environmental conditions may be modulated differently between the two lakes, which, despite their spatial proximity and reciprocal connection, do not always show contemporaneous functional processes. 相似文献
167.
The organic-rich shale of the Shanxi and Taiyuan Formation of the Lower Permian deposited in a marine-continental transitional environment are well developed in the Ordos Basin, NW China, which is considered to contain a large amount of shale hydrocarbon resources. This study takes the Lower Permian Shanxi and Taiyuan shale collected from well SL# in the Ordos Basin, NW China as an example to characterize the transitional shale reservoir. Based on organic geochemistry data, X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FE-SEM) observations, the desorbed gas contents of this transitional shale were systematically studied and the shale gas potential was investigated. The results indicate that the Lower Permian Shanxi and Taiyuan shale has a relatively high total organic carbon (TOC) (average TOC of 4.9%) and contains type III kerogen with a high mature to over mature status. XRD analyses show that an important characteristic of the shale is that clay and brittle minerals of detrital origin comprise the major mineral composition of the marine-continental transitional shale samples, while the percentages of carbonate minerals, pyrite and siderite are relatively small. FE-SEM observations reveal that the mineral matrix pores are the most abundant in the Lower Permian shale samples, while organic matter (OM) pores are rarely developed. Experimental analysis suggests that the mineral compositions mainly govern the macropore development in the marine-continental transitional shale, and mineral matrix pores and microfractures are considered to provide space for gas storage and migration. In addition, the desorption experiments demonstrated that the marine-continental transitional shale in the Ordos Basin has a significantly potential for shale gas exploration, ranging from 0.53 to 2.86 m3/t with an average value of 1.25m3/t, which is in close proximity to those of terrestrial shale (1.29 m3/t) and marine shale (1.28 m3/t). In summary, these results demonstrated that the Lower Permian marine-continental transitional shale in the Ordos Basin has a significantly potential for shale gas exploration. 相似文献
168.
169.
通过对南海东沙以南海域陆坡航磁异常特征的分析研究,指出引起各类磁异常的地质原因,认为本区陆坡地壳结构和陆壳相同,属于由陆壳到洋壳的过渡型地壳。同时,圈出东沙南磁性基底拗陷,推测该拗陷是一个很有希望的含油气盆地,并对该拗隐沉积层厚度进行了计算。 相似文献
170.
不少学者在准噶尔盆地腹部储层砂岩样品中检测到大量的明显高于样品所处地层经历的最高温度的包裹体均一温度数据。经作者研究发现,具有异常高均一温度的包裹体多为捕获自油水非均一体系的三相包裹体,显微镜下即可观察到包裹体内含有气相、液相油和液相水三相,油相在紫外光下发黄色荧光,气相和水相不发荧光,在不同井J1s、J1b样品中均有分布,且丰度极高,主要赋存于颗粒愈合裂隙及溶蚀成因的愈合微溶孔和颗粒次生加大边中,多与气态烃包裹体、含气态烃盐水包裹体、盐水包裹体以及纯液体包裹体等不同类型的包裹体共生,均一温度主要分布在130~200℃之间,无明显规律性。综合分析表明,这类包裹体形成于始新世-中新世时研究区内油气调整过程中迁移的油水过渡带中。根据共生的含气态烃盐水包 裹体均一温度,结合埋藏史和热演化史,恢复了包裹体捕获时,为38~17Ma,且浅 部比深部地层中包裹体形成时间较晚,代表了古油水界面到达某一深度的不同时间。 相似文献