共查询到19条相似文献，搜索用时 62 毫秒
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通过气体放置时间对观测结果影响的实验，得出气体放置时间对气体He、H2、O2、N2组分含量影响较小，而CO2组分含量随时间而衰减，其速度愈来愈慢的结论。 相似文献
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在地下气体观测的定量分析中,用气相色谱仪分析测量气体组分,是比较普遍的方法之一,气体分析资料的地震前兆反映明显,并且积累了不少典型震例,在地震预报研究中发挥了很好的作用。我们在观测实践中发现,即使严格按照规范(国家地震局,1985)的要求操作,仍有不少因素对观测数据的可靠性产生较大影响。为了提高气体观测资料的质量,对分析技术进行研究是完全必要的。 对庐江台1# 井的气体观测项目,就地下水溶解气和逸出气的观测过程,以SP-2304A型气相色谱仪的工作情况为例,结合笔者十几年的观测实践,对有关问题进行初步分析讨论,供同行参考。 1… 相似文献
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《地球物理学进展》2016,(1)
为了探讨深部岩体在破裂过程中气体运移规律,本文利用改进后电液伺服岩石力学三轴试验机和高精度气体监测装置,依据深部工程开挖后岩体中应力变化特点对加拿大Creighton矿区花岗岩样品进行温度-压力实验.在实验中观测到随着温度升高样品外表面连通裂隙内游离气体热膨胀向外界逸散,释放气体中各组分浓度变化趋势与温度成正相关.在温度和单轴压力作用下花岗岩样品破裂成核前监测到声发射密集出现,破裂产生大量张性裂隙为游离气体提供储气空间,短时间内造成气体压力突降并在裂隙内外之间形成压力梯度,驱动外界气体向新生裂隙回流.裂隙区域充满回流的气体后溢出CO_2、CH_4和H_2S.在围压持续增大过程中裂隙逐渐闭合同时排出大量游离气体.根据实验结果分析并讨论在岩体破裂过程中气体运移规律. 相似文献
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刘学领 《地震地磁观测与研究》2013,(5):188-192
对天津周良庄地热区不同含水层水化学背景开展实验研究,结果发现：随含水层埋藏深度加大,气体组分变化较大,水氡、水汞、离子组分变化较平稳,水氡背景值偏低.在此基础上,从含水层岩性、取样条件、水化学组分特性、地质构造等方面,对不同含水层之间水化学组分的差异性进行分析,认为区域内特殊地质构造是影响差异性的重要因素. 相似文献
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2012年10月、2013年5月和9月对新04、新10泉进行了流体地球化学采样,实验得到两泉的同位素、离子组分、气体组分测试数据。通过分析测试结果研究两泉的流体地球化学特征。结果表明,两泉的水化学类型为Na(Mg)-SO_4和Na(Ca)-SO_4(HCO_3),主要形成于大气降水深循环过程中与围岩间的水岩反应;两口泉气样的CO_2为有机来源和无机来源的混合,He为大气来源与地壳来源的混合。两口泉水样的离子组分浓度第一次采样结果和后两次采样结果出现了明显变化,可能与该地区的地震活动增强有关。 相似文献
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利用观测精度可达1～2×10-8ms-2_,的FG5 绝对重力仪,开展了空气阻力、有无隔震弹簧以及仪器自震对重力观测影响等观测实验.通过在环境干扰较小的九峰站观测实验,得到如下结论:在正常大气压状态下所观测到的空气阻力影响约500×10-5ms-2,比理论估算值大近30×105ms-2, 若在低真空状态测量空气阻力也将产生2.3×10-5 ms-2观测误差;落体室真空度维持系统(离子泵)工作不正常,空气阻力也将对重力观测造成0.1～4.1×10-5ms-2的观测误差;在地质条件比较稳定,环境震动干扰较小的基墩上测量,隔震弹簧的作用对观测结果影响不明显,但对测量精度影响较大.上述观测实验的进行,为自由下落法绝对重力仪的研制提供可靠依据. 相似文献
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本文根据１９９３年６月至１９９４年１月滇西及其邻近地区数次中强以上地震前ＣＯ２，Ｎ２，Ａｒ，Ｒｎ等气体组分释放动态的观测结果，研究了气体的物质迁移对其前兆异常变化的影响，发现深，浅源气体的震前趋势性异常释放和短临突跳异常的发生时间具有明显的有序性，基本模式是源自深部的气体组分的震前异常变化总是上先于浅源气体，这种现象在强震发生前更为明显。作者认为，导致深一浅源气体异常变化有序发生的原因与气体物质迁 相似文献
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Arumugam Sakunthalai Ramadhas Chandrasekaran Muraleedharan Simon Jayaraj 《洁净——土壤、空气、水》2008,36(12):978-983
Biodiesel is a renewable alternative fuel that can be used as substitute for mineral diesel. The use of biodiesel in diesel engines reduces all of the exhaust emissions expect NOx. The higher temperature in the combustion chamber increases the NOx emissions. The recirculation of a small percentage of cooled exhaust gases into the combustion chamber through the intake manifold reduces the in‐cylinder temperature. Moreover, the cooling of exhaust gases before mixing with fresh air introduced to the engine does not affect its volumetric efficiency but it absorbs the heat of combustion. This leads to a reduction in NOx emissions and improves the engine brake thermal efficiency. This paper describes the investigation of the performance and emission characteristics of a biodiesel‐fueled, naturally aspirated, single cylinder diesel engine with cooled exhaust gas recirculation. 相似文献
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Rn、CO2、Hg、H2等断层气体被广泛应用于断层活动性以及断层结构特征的研究。当前，研究介质中压力变化与断层气间的关系是断层气映震研究的主要技术方法之一。新疆呼图壁地下储气库自建成以来，每年以周期性循环“注入/采出”模式运行，该运行模式带来的储气库气压变化会影响周围地区的地震活动。同时，这一定期加压存储与减压释放气体的过程为研究应力变化引起的断层气变化提供了天然的实验场。通过对呼图壁储气库开展断层气定期流动测量以及定点连续观测，获取反复加载、卸载气体过程中储气库及周边区域断层气体Rn、CO2、Hg、H2浓度的变化特征，在储气库区域内观测到明显的Hg、H2浓度高值现象，其最大值分别为190ng/m3和725.40ppm，且其空间分布特征表现为在储气库加压存储过程中，储气库区域内注采井附近的气体浓度高于储气库区域外；此外，长期连续观测结果表明，断层气H2与储气库的压力变化存在一定的关系，H2对储气库内压力变化的响应更为灵敏。对呼图壁储气库应力变化引起的断层气变化特征进行分析，可以认识不同应力状态下断层气变化特征，为地震台站勘选与建设、震情跟踪以及异常落实等提供地球化学科技支撑。 相似文献
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Analytical Solutions for Gas Flow Due to Gas Injection and Extraction from Horizontal Wells 总被引：2，自引：0，他引：2
Ronald W. Falta 《Ground water》1995,33(2):235-246
Analytical solutions are developed for modeling the transient and steady-state gas pressure and the steady-state streamfunction fields resulting from gas injection and extraction from a pair of parallel horizontal wells. These solutions apply to cases in which the ground surface is open to the atmosphere, and in which the porous media is anisotropic but homogeneous. By neglecting end effects due to the finite length of the wells, the three-dimensional gas flow field is approximated as a two-dimensional cross section perpendicular to the wells. These solutions may be used to develop estimates of the horizontal well system behavior and to analyze horizontal well gas pump tests, and are useful for numerical model verification. 相似文献
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In the exploration of the hidden Haihe fault, radon and mercury in soil gas were measured by using FG-3017 radon detector and XG-4 mercury analyzer. In this paper, based on the measurement results of 12 fault gas profiles, and integrating with the exploration results of artificial seismic prospecting, the relationship between anomalous site of fault gas and fault location is analyzed. Using the relationship between anomalous strength of fault gas and fault activity, the activity of Haihe fault is studied, thus the location and activity segmentation of the Haihe fault in Tianjin region are presented. This study shows that the method of fault gas detection can not only identify the preliminary location of fault, but also make preliminary segmentation of fault activity. The fault detected by the method of fault gas measurement is shown as a band. Through contrasting with exploration results of artificial seismic prospecting and analyzing, we find that the fault is located inside the band. According to the measurements of soil gas radon, the Haihe fault can be divided into east and west segments and the activity of the east segment of Haihe fault is stronger than that of the west segment. This is only a relative result, and it is difficult to judge whether the fault is active or not with this result. 相似文献
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Active faults are commonly associated with spatially anomalously high concentrations of soil gases such as carbon dioxide
and Rn, suggesting that they are crustal discontinuities with a relatively high vertical permeability through which crustal
and subcrustal gases may preferably escape towards the earth's surface. Many earthquake-related hydrologic and geochemical
temporal changes have been recorded, mostly along active faults especially at fault intersections, since the 1960s. The reality
of such changes is gradually ascertained and their features well delineated and fairly understood. Some coseismic changes
recorded in ``near field' are rather consistent with poroelastic dislocation models of earthquake sources, whereas others
are attributable to near-surface permeability enhancement. In addition, coseismic (and postseismic) changes were recorded
for many moderate to large earthquakes at certain relatively few ``sensitive sites' at epicentral distances too large (larger
for larger earthquakes, up to 1000 km or more for magnitude 8) to be explained by the poroelastic models. They are probably
triggered by seismic shaking. The sensitivity of different sites can be greatly different, even when separated only by meters.
The sensitive sites are usually located on or near active faults, especially their intersections and bends, and characterized
by some near-critical hydrologic or geochemical condition (e.g., permeability that can be greatly increased by a relatively
small seismic shaking or stress increase). Coseismic changes recorded for different earthquakes at a sensitive site are usually
similar, regardless of the earthquakes' location and focal mechanism. The sensitivity of a sensitive site may change with
time. Also pre-earthquake changes were observed hours to years before some destructive earthquakes at certain sensitive sites,
some at large epicentral distances, although these changes are relatively few and less certain. Both long-distance coseismic
and preseismic changes call for more realistic models than simple elastic dislocation for explanation. Such models should
take into consideration the heterogeneity of the crust where stress is concentrated at certain weak points (sensitive sites)
along active faults such that the stress condition is near a critical level prior to the occurrence of the corresponding earthquakes.
To explain the preseismic changes, the models should also assume a broad-scaled episodically increasing strain field. 相似文献
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地震前兆观测是地震预报的基础。地震流体前兆观测在水资源过度开采的形势下,发展断层土壤气观测成为必然趋势。但地下流体观测技术规范未给出断层土壤气观测的集气-采气装置及采气条件的具体参数,而这些参数正是影响观测结果的重要因素。因此,本文对断层土壤气气氡观测的采气条件进行了实验研究及分析。结果表明,当日采气量一定时,集气室体积的大小对观测结果有较大影响。运用"采气率"这个概念来定量衡量断层土壤气观测装置系统的实用效果。集气室有效体积的大小应根据日采气量的多少来确定,采气量越大,集气室有效体积应越大,结合地震前兆观测实际,采气率应接近于1。本文实验研究结果对规范断层土壤气气氡观测提供了科学依据,也可供其它气体观测参考。 相似文献