超临界CO2作用下页岩力学特性损伤的试验研究

随着社会对清洁能源的需求不断扩大,超临界CO2强化页岩气开发技术受到广泛关注。为研究超临界CO2对页岩力学特性的影响,将四川盆地志留系龙马溪组页岩作为研究对象,对其进行不同浸泡时间条件下的超临界CO2浸泡试验,并通过劈裂试验和三轴压缩试验,获得浸泡前后页岩强度与变形的变化规律,进而结合SEM、XRD等系列页岩微观测试,初步探讨超临界CO2与页岩的相互作用机制。研究结果表明：超临界CO2浸泡后页岩的抗拉强度、三轴抗压强度、弹性模量均出现不同程度的下降,而随浸泡时间的加长,页岩强度的损失量增大。初步分析表明：在超临界CO2作用下,一方面改变了页岩的颗粒骨架和孔隙结构,另一方面改变了页岩的矿物成分组成,降低页岩岩石颗粒间的胶结程度,从而劣化页岩的力学性质。     

气饱和含CO2水合物砂的三轴压缩试验

在改造的高压低温三轴仪中采用过量气法制备了气饱和状态的含CO2水合物砂样,并进行了三轴压缩试验。以水合物饱和度为指标对过量气制样法的可重复性进行分析后发现,受孔隙阻隔效应的影响,虽然利用高的初始水饱和度的砂样可以制成高的水合物饱和度的含水合物砂,但是制样的可重复性低;试验表明,采用过量气法制取水合物饱和度低于40%的含水合物试样的可重复性较好。三轴试验结果表明,含水合物砂的剪切和变形特性与水合物饱和度和净围压密切相关：随净围压的增大,试样的强度、刚度、塑性和压缩性都增大,随水合物饱和度的增加,试样的强度和刚度增加,塑性和压缩性降低;黏聚力随水合物饱和度的增加而增加,但摩擦角并没有明显的变化。     

Retrieval of tropospheric co profiles using correlation radiometer. ii: effects of other gases and the retrieval in cloudy atmosphere

The effects of methane, ozone, water vapor and nitrous oxide on the retrieval of tropospheric CO profiles using correlation radiometer have been assessed. The scheme of the retrieval in the presence of solid clouds have been proposed. The effect of methane and nitrous oxide can be well accounted by their mean profile, and that of ozone can be represented by a typical middle latitude ozone profile, while for water vapor, less than 50% uncertainty is required. With the assumption of blackbody for cloud surface, the CO profile may be retrieved for low and middle solid clouds. However, the retrieval of CO profile will lose quality for high clouds.     

行星状星云中CO(1-0)谱线发射的新观测

利用紫金山天文台青海观测站１３．７ｍ射电望远镜,对５个行星状星云给出了新的谱线观测结果。其中行星状星云Ｍ１－８和Ｍ３－３已探测到ＣＯ（２－１）的发射,给出了它们的ＣＯ（１－０）观测结果;为曾进行过ＣＯ观测,但未探测到ＣＯ发射的行星状星云Ｍ１－１２、Ｍ２－４３和ＮＧＣ６５３７,第一次证认了它们的ＣＯ（１－０）发射。     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

海洋板块俯冲作用下上覆大陆岩石层减薄机制的动力学模拟

几乎所有大陆岩石层的减薄现象,可能都与海洋板块的俯冲作用相关,但是两者之间的内在联系迄今仍不十分明确,为此,我们设计了一系列包含洋-陆俯冲系统的二维数值模型,来探讨海洋板块的俯冲作用对上覆大陆岩石层变形行为的影响,尤其对大陆岩石层减薄效应的制约.模型结果表明,海洋板块俯冲过程中的地幔楔熔体对大陆岩石层地幔的热侵蚀以及由熔体上升所诱发的地幔局部对流的强烈扰动会导致上覆大陆岩石层的减薄效应.这种效应不仅表现在横向上的向陆内蔓延,还表现在垂向上的向浅部发展.且多类动力学参数都能制约大陆岩石层的减薄效应.具体地,随着汇聚速率和洋壳厚度的增加,上覆大陆岩石层在横向上的减薄范围越大,在垂向上的减薄程度也越深;而随着俯冲海洋板块年龄的增加,上覆大陆岩石层在横向上的减薄范围增大,但在垂向上的减薄程度会减小;随着上覆大陆岩石层厚度的增加,其横向减薄范围会减小,但在垂向上的减薄程度会加深.本文研究成果能为揭示华北克拉通减薄/破坏的动力学过程提供一定的理论参考依据.     

Effect of supercritical CO2 on carbonates: Savonnières sample case study

CO₂ geosequestration is an efficient way to reduce greenhouse gas emissions into the atmosphere. Carbonate rock formations are one of the possible targets for CO₂ sequestration due to their relative abundance and ability to serve as a natural trapping reservoir. The injected supercritical CO₂ can change properties of the reservoir rocks such as porosity, permeability, tortuosity, and specific surface area due to dissolution and precipitation processes. This, in turn, affects the reservoir characteristics, i.e., their elastic properties, storage capacity, stability, etc. The tremendous progresses made recently in both microcomputed X‐ray tomography and high‐performance computing make numerical simulation of physical processes on actual rock microstructures feasible. However, carbonate rocks with their extremely complex microstructure and the presence of microporosity that is below the resolution of microcomputed X‐ray tomography scanners require novel, quite specific image processing and numerical simulation approaches. In the current work, we studied the effects of supercritical CO₂ injection on microstructure and elastic properties of a Savonnières limestone. We used microtomographic images of two Savonnières samples, i.e., one in its natural state and one after injection and residence of supercritical CO₂. A statistical analysis of the microtomographic images showed that the injection of supercritical CO₂ led to an increase in porosity and changes of the microstructure, i.e., increase of the average volume of individual pores and decrease in the total number of pores. The CO₂ injection/residence also led to an increase in the mean radii of pore throats, an increase in the length of pore network segments, and made the orientation distribution of mesopores more isotropic. Numerical simulations showed that elastic moduli for the sample subjected to supercritical CO₂ injection/residence are lower than those for the intact sample.     

基于密度泛函理论研究K对Li2CO3晶体影响规律

以盐湖卤水为原料提取并制备Li₂CO₃的过程中,共存离子对其结晶过程影响较大,尤其我国西藏盐湖卤水为原料制备碳酸锂的原料中,K/Li约为0.3左右,所以研究K⁺对Li₂CO₃晶体的影响具有重要意义。通过实验和计算模拟相结合研究不同K/Li条件下K⁺对Li₂CO₃晶体的影响程度,建立晶体中K⁺含量与比表面积关联式。实验结果表明,K⁺的存在对Li₂CO₃的高品质性影响较大,且随着钾离子含量增加,晶体比表面积增大易于吸附杂质离子,表面粗糙度增强,且K⁺存在对碳酸锂晶体的收率影响较大,而当K/Li控制在0.1以内时,K⁺对碳酸锂晶体的影响相对较小。通过第一性原理计算,计算并分析了K掺入碳酸锂晶体中的几何结构、缺陷形成能及态密度,结果表明K原子在碳酸锂晶体中更易替代晶体中的Li原子,K原子的掺...     

山东沂源九天洞洞穴环境变化监测分析

为改善九天洞洞穴环境质量及保护洞穴景观提供科学依据,2006年5月1—5日和2006年7月28—30日曾两度对该洞的洞穴空气温度、湿度、CO2浓度和游客量的变化进行实地监测。结果表明,九天洞CO2浓度受游客数量影响,具有明显累积效应,其中灵霄玉塔（测点11）CO2浓度最高,日平均值为11250ppm;CO2浓度之高,国内外颇为罕见;而洞穴温度兼受洞穴滴水及洞穴形态的影响,具有一定的变化幅度;洞穴湿度除了受天气影响外,游客呼吸对封闭洞段湿度增大也有一定的贡献作用。