现代黄河三角洲粉土触变性研究及其应用

通过对现代黄河三角洲砂质粉土和粉质粘土触变性的对比试验研究，阐述了黄河口粉土的触变性。试验结果对解释粉土的失稳机制、解决工程地基的稳定性和防止地质灾害等具有重要的现实意义。     

Freshening of the Intermediate Waters in the Northern South China Sea over the PastSix Decades

The properties of salinity in the South China Sea (SCS), a significant marginal sea connecting the Pacific andIndian Oceans, are greatly influenced by the transport of fresh water flux between the two oceans. However, the long-termchanges in the intermediate water in the SCS have not been thoroughly studied due to limited data, particularly in relationto its thermodynamic variations. This study utilized reanalysis data products to identify a 60-year trend of freshening in theintermediate waters of the northern South China Sea (NSCS), accompanied by an expansion of low-salinity water. Thestudy also constructed salinity budget terms, including advection and entrainment processes, and conducted an analysis ofthe salinity budget to understand the impacts of external and internal dynamic processes on the freshening trend of theintermediate water in the NSCS. The analysis revealed that the freshening in the northwest Pacific Ocean and theintensification of intrusion through the Luzon Strait at intermediate levels are the primary drivers of the salinity changes inthe NSCS. Additionally, a weakened trend in the intensity of vertical entrainment also contributes to the freshening in theNSCS. This study offers new insights into the understanding of regional deep sea changes in response to variations in boththermodynamics and oceanic dynamic processes.     

准噶尔盆地中部III 区块原油中25-降藿烷分布特征与成因意义

通过对准噶尔盆地中部Ш区块原油或油砂抽提物的饱和烃气相色谱-质谱分析,研究了原油或油砂抽提物中25-降藿烷的分布规律.结果表明,不同井区或同一口井不同深度(层位)的原油25-降藿烷的相对含量存在比较明显的差别,表明其所遭受的生物降解程度有所差异,沿构造带从南到北,同一油层中原油的生物降解程度增强,比如位于构造北部(构造部位相对较高)的永1井、永3井侏罗系原油25-降藿烷丰度较高,表明生物降解比较明显,而位于南部(构造低部位)的永6井白垩系和侏罗系油层中的原油均无明显的生物降解现象;同一口井随深度增大生物降解作用将弱,如永2井浅部白垩系油层的原油降解较严重,而深部西山窑组的原油降解作用则不明显.根据原油生物降解的特征,结合车-莫古隆起调整对研究区油气成藏的影响,讨论了原油生物降解差异分布的成因机制.     

壳幔混染作用——下扬子区早中生代玄武岩同位素地质特征

下扬子区中生代（231Ma）玄武质火山岩全岩εNd（t）值-8.62～1.92,87Sr/86Sr 值0.7074～0.7179，206Pb/204Pb值为17.786～18.323。岩石中含有前寒武纪捕虏晶锆石。研究表明玄武质岩石可能是由亏损地幔与元古宙地壳岩石混染作用的结果。     

扬子地台钾镁煌斑岩 Nd、Sr、Pb 同位素特征

扬子地台周缘钾镁煌斑岩 Nd、Sr同位素特征介于南非Ⅰ、Ⅱ型金伯利岩和西澳与北美钾镁煌斑岩两种变化趋势之间，不同岩区间同位素组成差异反映地台周边构造性质不同，Pb同位素特征表明晚太古代地幔岩石圈具U亏损特征。     

辽西中生代火山岩岩浆成因——稀土元素配分及同位素定量模式

本文通过对辽西及邻区中生代盆地火山岩稀土元素配分特征的研究及模拟运算，探讨了其岩浆成因及过程。结果显示南北岩区岩浆成因不同，南岩区岩源为MORB地幔和长期富集型幔熔融混合而成，北岩区为MORB和近期亏损型地幔熔融混合而成。     

甲醛还原Pt/TiO2催化剂用于温和条件下高效催化氧化甲醛（英文）

通过浸渍法(IM)和沉积-沉淀(DP)法制备了一系列Pt/TiO2P25)催化剂,并分别用甲醛溶液和氢气还原处理催化剂.利用原位红外监测催化剂表面吸附物种在反应过程中的变化,探究了催化剂制备和还原条件及Pt负载量对催化剂结构和催化氧化甲醛活性的影响.结果显示,用DP法制备并用甲醛还原的Pt/P25催化剂中Pt颗粒分散均匀,并具有合适的粒径和高浓度的表面活性氧,显示出良好的甲醛氧化活性.在空速30 000 ml/(g·h)、反应温度30°C和甲醛初始浓度50 mg/m的条件下,0.4%Pt/P25(DP-HCHO)上的甲醛转化率达到98%,并能稳定运行100 h以上.相比之下,Pt/P25(DP-H2)由于表面活性氧较少,不利于甲酸盐氧化,活性较低.Pt/P25(IM-H2)虽然具有高浓度的表面活性氧,却同时具有最大的Pt颗粒粒径,在甲醛转化为甲酸盐和甲酸盐氧化两步反应中的活性均较差,因而甲醛氧化活性最差.     

GRADIENT DISTRIBUTION OF ACID RAIN IN THE SCENIC RESORT OF THE BAIYUN MOUNTAIN IN GUANGZHOU

1 INTRODUCTION Sitting in the central part of the Pearl River Delta, Guangzhou is one of the cities in China that are most polluted by acid rain. Broad attention has been brought to the problem. Since the early 1980s, a series of observation and studies h…     

CHARACTERISTICS OF ATMOSPHERIC HEAT SOURCE ASSOCIATED WITH THE SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA AND THE POSSIBLE MECHANISM RESPONSIBLE FOR ITS LATE OR EARLY ONSET

The characteristics of atmospheric heat source associated with the summer monsoon onset in the South China Sea (SCS) are studied using ECMWF reanalysis data from 1979 to 1993. A criterion of the SCS summer monsoon onset is defined by the atmospheric hea…