草簇状石墨烯片限域Pd纳米粒子及其催化应用(英文)

通过氨基离子液体改性石墨烯,并将其固载于堇青石表面,作为负载型Pd催化剂的载体.所制备的Pd催化剂经加氢老化后,表面石墨烯呈草簇状结构,将Pd纳米粒子限域于片层内,有效防止了Pd的流失和团聚.在重要的工业反应对羧基苯甲醛(4-CBA)加氢中,此结构催化剂与传统的钯碳催化剂相比,表现出很好的稳定性     

Excel在约旦18号死海海堤沉降监测中的应用

通过死海南端约旦18号海堤的沉降监测实例,总结了用Microsoft Excel在国外进行沉降监测资料整理的方法和体会,并较为全面地介绍了各类图表的意义,这些方法可在类似的监测工作中予以借鉴。     

高岭石—莫来石反应系列：^27Al和^29SiMAS NMR研究

根据艰我国八个不同成因和特征的高岭土样品在４５０－１４５０℃热处理产物的ＭＡＳ ＮＭＲ谱和ＸＲＤ，ＩＲ，ＤＴＡ等研究结果，结合有关资料讨论了高岭石－莫来石反应序列的几个重要问题：１．高岭石的结构，尤其是五配位铝；２．９８０℃放热峰后的高温相是γ－Ａｌ２Ｏ３而不是Ａｌ－Ｓｉ尖晶石；３．对于莫来石化过程，认为初始莫来石８５０－９５０℃变高岭石形成，二次莫来石由分凝的ＳｉＯ２和γ－Ａｌ２Ｏ３在１２００－     

Dynamic selection of emergency plans of geological disaster based on case-based reasoning and prospect theory

Natural Hazards - The Three Gorges reservoir area in the Yangtze River economic belt has frequent geological disasters. To assist decision-makers make effective emergency decisions based on their...     

Dynamic Analysis of a Single-Column Platform (II)

This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained.     

新疆阿希金矿床地球物理特征

阿希金矿床含金石英脉具高阻、高极化、高密度特征，蚀变英安岩呈低阻、低极化、高密度和无磁性，构造破碎带为低阻、低密度特征。以下石炭统阿恰勒河组及大哈拉军山组部分岩性为背景场，并在二者接触部位陪衬出次一级高阻、高极化、微磁，较明显的低负自然电位；位于磁场负极值间的△Ｚ值趋于零的过渡平台的出现；地表低的自然伽马射线；矿体沿一定位移方向ηｓ异常出现等，是寻找该类型矿床的重要物性标志。     

Metal Ion Extraction with Bipyridine Derivatives as Chelating Ligands in Supercritical Carbon Dioxide

Three fluorinated bipyridine ligands have been designed and synthesized as chelating agents for the extraction of metal ions in supercritical CO₂ (sc‐CO₂). The ligand solubilities in sc‐CO₂ were investigated at different temperatures and pressures, and the measured data have been correlated using a semiempirical model. The calculated results showed satisfactory agreement with the experimental data. Based on these data, metal ion extraction with the three compounds as chelating agents in sc‐CO₂ was performed from spiked filter paper, whereby ligand 1 showed the highest extraction efficiency, especially for Ni²⁺ and Cu²⁺. The extraction constants, K_ex, of the three chelating ligands were seen to increase with increasing extraction efficiency for the same metal ion in the same extraction system.     

Electrical conductivity of hydrous silicate melts and aqueous fluids: Measurement and applications

The combination of magnetotelluric survey and laboratory measurements of electrical conductivity is a powerful approach for exploring the conditions of Earth’s deep interior. Electrical conductivity of hydrous silicate melts and aqueous fluids is sensitive to composition, temperature, and pressure, making it useful for understanding partial melting and fluid activity at great depths. This study presents a review on the experimental studies of electrical conductivity of silicate melts and aqueous fluids, and introduces some important applications of experimental results. For silicate melts, electrical conductivity increases with increasing temperature but decreases with pressure. With a similar Na⁺ concentration, along the calc-alkaline series electrical conductivity generally increases from basaltic to rhyolitic melt, accompanied by a decreasing activation enthalpy. Electrical conductivity of silicate melts is strongly enhanced with the incorporation of water due to promoted cation mobility. For aqueous fluids, research is focused on dilute electrolyte solutions. Electrical conductivity typically first increases and then decreases with increasing temperature, and increases with pressure before approaching a plateau value. The dissociation constant of electrolyte can be derived from conductivity data. To develop generally applicable quantitative models of electrical conductivity of melt/fluid addressing the dependences on temperature, pressure, and composition, it requires more electrical conductivity measurements of representative systems to be implemented in an extensive P-T range using up-to-date methods.     

Freshwater flocculation of suspended sediments in the Yangtze River, China

This study focuses on suspended sediments and in situ flocculation in the Yangtze River, with the goal of improving our understanding of the relationship between freshwater and estuarine flocculation. A field survey with state-of-the-art instruments was carried out in January 2008 in the reach from downstream of the Three Gorges Dam to the estuary. The data show that in situ floc mean diameters range from 22 to 182???m in the river, whereas the median dispersed grain sizes are 4.4?C11.4???m. This demonstrates that flocculation is an important process during the transport of suspended sediments along the river. The flocculation characteristics, suspended sediment concentration and dispersed grain sizes all vary longitudinally in the main stream of the Yangtze River. Biochemical factors are likely be more significant in the freshwater flocculation than in the estuary, where hydrodynamics and biochemical factors are both important. Flocculation is found in the freshwater river, in the estuary and in coastal waters, which indicates that dynamic break-up/reflocculation processes take place during the suspended sediment transport. The freshwater flocs may behave as parent flocs to the estuarine flocculation. This study enhances our understanding of flocculation from estuarine and coastal areas to fresh river systems and provides insights into the effects of input of riverine flocs to the estuarine flocculation and into the sources and fate of flocs.     

相对位移反分析的DFP优化方法及其工程应用

洞室围岩的某些参数,如弹性模量、强度参数等,对地下洞室的施工和设计具有极其重要的作用,直接进行这些参数的现场测量势必要耗费大量的物资和精力,在这种背景下,位移反分析的工程应用具有很重要的理论和实用价值。但洞室工程中大量不确定性因素的存在使得监测结果不可避免地存在随机性,有时会使得变形监测结果产生较大的误差,甚至失真。因此以监测结果的绝对值所反演得到的参数可能是错误的。在这种情况下,以监测数据的相对值进行参数反演在一定程度上可以消除测量误差。基于相对位移的随机反分析法并结合DFP优化算法开发了基于相对位移的随机反分析法,将其应用于一具体洞室工程中反演其弹性模量取得了较为理想的效果。