新安江流域上空云内外巨盐核的分布

1979—1980年6—7月份在新安江流域上空进行了云内外巨盐核的观测,得到:(1)大气中云内外的巨盐核浓度分布都与天气背景有关;(2)云内巨盐核浓度大于同高度上的云外巨盐核浓度,不同云内巨盐核浓度和谱型不一样;(3)云内巨盐核浓度要比小云滴少两个量级,因此巨盐核作为凝结核,对形成小云滴的贡献是很小的。     

570矿床控制因素及富矿形成条件

570矿床地质背景是破火山旋回边缘活动带;矿床定位要素是受破火山断裂系统构造结控制的隐爆角砾岩筒;隐爆加断陷组成的聚矿结构,是富矿形成的主要条件;隐爆角砾岩筒与次火山花岗岩浆侵位组成的热泵汲取效应,是矿床基本成因模式。矿床扩大方向是在探索隐爆角砾岩筒深部的同时,沿边缘活动带,在破火山断裂系统构造结处寻找新的隐爆角砾岩筒。     

六盘山东麓晚更新世以来黄土粒度指示的物源特征及演变

在宁夏长城塬完整的晚更新世-全新世黄土-古土壤剖面(长城塬剖面)进行高分辨率采样,对125个样品的粒度数据做了粒度端元分析,并对各端元组分含量在地层深度尺度上做了小波分析。结果认为：端元分析法可以把代表4种不同动力的沉积端元分离出来。端元1可能代表了西风带控制下的由高空气流搬运的远源粉尘物质;端元2可能代表了沉积物沉积后在东亚夏季风作用下的风化以及成壤改造作用;端元3可能代表了后期的淋溶作用动力特征;端元4可能代表了东亚冬季风作用下典型的风成黄土粗颗粒组分特征。根据小波分析认为各端元组分含量在不同的深度上均存在着准周期变化,指示了相对应的时间尺度上古季风变化具有准周期性的特征,同时也说明了沉积剖面一直处于较为连续沉积状态,比较完整地记载了各沉积动力过程。各端元组分在不同的时间尺度上具有不同的准周期性特征。     

Discussion of paper ‘Simulation of floor response spectra in shake table experiments’ by G. Maddaloni,K. P. Ryu and A. M. Reinhorn,Earthquake Engineering and Structural Dynamics 2011; 40(6): 591‐604

Three main topics including the floor motion action mechanism, the test frame design, and the target spectrum simulation presented in the paper are discussed specifically. Floor motion action mechanism is critical in understanding the seismic performance of architectural nonstructural components. Seismic sensitiveness and earthquake response properties of the nonstructural components should be considered in the design of the test frame for the shaking table test. Target spectrum simulation is also a challenging job in the shaking table test, in which dynamic characteristics of the specimen, performance of the shaking table facilities, and the control techniques should be all considered. Copyright © 2011 John Wiley & Sons, Ltd.     

Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

INTRODUCTIONAs a new and effective method for withstandingthe horizontal component of earthquake motion on abuilding structure, the base isolation technique hascome to the engineering application phase ( Hu,1988). However, for some important buildings andfoundation facilities in an earthquake region, it is im portant to consider the effects of 3D aseismatic analy sis, including the vertical component, due to themulti dimensional characteristics of earthquakes (Suand …     

湖南七里坪夕卡岩型硼矿床的矿石特征及其矿床学意义

七里坪硼矿床的主要矿石类型从岩石学角度看是方解石岩 ,它们由硼矿物和方解石组成 ,二者都是含硼气液交代白云石大理岩 (围岩 )的结果。矿石的化学成分既富钙又富镁 ,钙来自方解石 ,镁来自硼矿物 ,贫其它成分 ,因此夕卡岩型硼矿床不是传统的镁夕卡岩矿床 ,而是钙镁质夕卡岩矿床。     

Secondary hydrocarbon generation potential from heavy oil, oil sand and solid bitumen during the artificial maturation

Secondary hydrocarbon generation potentials from natural bitumen, oil sand and heavy oil, representing different residual oil accumulations, were determined by artificial maturation in a closed pyrolysis system. Simulated results indicate that their thermal behavior and reactivity are similar to those of kerogen, and that they can generate hydrocarbons once subjected to suitable geological processes. Overall differences in oil and gas generation potentials among the samples result from differences in the chemical structure of precursor components, physical compaction status, and mineral matrices. Hydrogen rich precursors, such as oil sand and heavy oil, have greater potential to generate hydrocarbons than hydrogen poor ones. Naturally compacted oil sand has slightly higher conversion efficiency than artificially compacted heavy oil as indicated by lower residual bitumen content. However, total gas and liquid oil recovery from oil sand is lower than from heavy oil due to the poor release of pyrolytic products from well compacted and cemented networks in the experiments. Mineral matrices of previous oil deposits also affect further hydrocarbon generation potential. Carbonate matrices inhibit total oil and gas generation, which consequently retains high gas potential at the postmature stage. Traditional oil generation models mainly consider the thermal alteration of kerogen; this study provides supplemental information for superimposed basins where previous oil accumulations may have been destroyed and reburied to serve as secondary sources of oil and gas. Consideration of previous oil residues as potential source rock allows better estimates of available oil resources and the risks associated with their exploration.     

湘赣边界鹿井铀矿床流体包裹体及成矿机制

位于南岭成矿带南西部的鹿井矿床是华南热液型铀矿的典型代表.为查明其成矿流体来源、性质与演化以及成矿机制,开展了不同成矿阶段石英、萤石及方解石中流体包裹体的显微测温和不同阶段石英的氢?氧同位素分析.矿床地质特征表明成矿过程可划分为(I)粗晶石英+黄铁矿±绿泥石±绢云母、(II)沥青铀矿+硫化物+绿泥石+绢云母+暗灰色微晶...     

洞庭湖流域降水同位素与ENSO关系研究

基于洞庭湖流域内长沙市2010年1月至2012年12月降水事件、GNIP(Global Network for Isotopes in Precipitation)长沙站1988~1992年月降水同位素资料及ENSO（厄尔尼诺/拉尼娜和南方涛动）的2个常用指标（南方涛动指数SOI和Nino3区海面温度SST）,分析了流域降水同位素与ENSO关系。结果表明：洞庭湖流域降水中δ¹⁸O与降水量、气温在日、月尺度上均呈负相关且只有月度上与降水量的负相关不显著。洞庭湖流域降水中δ¹⁸O与ENSO的SST指标则呈显著正相关。ENSO对洞庭湖流域降水同位素的影响机制可能如下：春季,La Nina年源自西太平洋的东南风强盛,其转向为西南风的区域达到印度洋,而El Nino年,东南风转向为西南风的发生区域位于印度洋以东,前者有利于挟带印度洋远源水汽向中国东部区域输送,进而造成降水同位素的贫化;夏季,La Nina年印度洋水汽输送在中国南海转为经向继而向北延伸,而El Nino年,源自印度洋的水汽沿纬向穿过南海,在东海转向往北延伸,后者有利于挟带西太平洋的近源水汽输送到中国东部季风区,进而引起降水同位素的富集。     

Diurnal Variations of Carbon Dioxide, Methane, and Nitrous Oxide Vertical Fluxes in a Subtropical Estuarine Marsh on Neap and Spring Tide Days

Measuring fluxes of greenhouse gases (GHGs) is fundamental to estimating their impact on global warming. We examined diurnal variations of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) vertical fluxes in a tidal marsh ecosystem. Measurements were recorded on neap and spring tide days in April and September 2010 in the Shanyutan wetland of the Min River estuary, southeast China. Here, we define a positive flux as directing into the atmosphere. CH₄ fluxes on the diurnal scale were positive throughout, and CH₄ emissions into the atmosphere on neap tide days were higher than on spring tide days. CH₄ releases from the marsh ecosystem on neap tide days were higher in the daytime; however, on spring tide days, daily variations of CH₄ emissions were more complex. The marsh ecosystem plays a twofold role in both releasing and assimilating CO₂ and N₂O gases on the diurnal scale. Average CO₂ fluxes were positive on the daily scale both on neap and spring days and were greater on the neap tide days than on spring tide days. Diurnal variations of N₂O fluxes fluctuated more. Over the diurnal period, soil temperature markedly controlled variations of CH₄ emissions compared to other soil factors, such as salinity and redox potential. Tidal water height was a key factor influencing GHGs fluxes at the water–air interface. Compared with N₂O, the diurnal course of CO₂ and CH₄ fluxes in the marsh ecosystem appeared to be directly controlled by marsh plants. These results have implications for sampling and scaling strategies for estimating GHGs fluxes in tidal marsh ecosystems.