The carbonate system in the East China Sea in winter

Measurements of dissolved inorganic carbon (DIC), pH, total alkalinity (TA), and partial pressure of CO₂ (pCO₂) were conducted at a total of 25 stations along four cross shelf transects in the East China Sea (ECS) in January 2008. Results showed that their distributions in the surface water corresponded well to the general circulation pattern in the ECS. Low DIC and pCO₂ and high pH were found in the warm and saline Kuroshio Current water flowing northeastward along the shelf break, whereas high DIC and pCO₂ and low pH were mainly observed in the cold and less saline China Coastal Current water flowing southward along the coast of Mainland China. Difference between surface water and atmospheric pCO₂ (ΔpCO₂), ranging from ~ 0 to ? 111 μatm, indicated that the entire ECS shelf acted as a CO₂ sink during winter with an average flux of CO₂ of ?13.7 ± 5.7 (mmol C m^? 2 day^? 1), and is consistent with previous studies. However, pCO₂ was negatively correlated with temperature for surface waters lower than 20 °C, in contrast to the positive correlation found in the 1990s. Moreover, the wintertime ΔpCO₂ in the inner shelf near the Changjiang River estuary has appreciably decreased since the early 1990s, suggesting a decline of CO₂ sequestration capacity in this region. However, the actual causes for the observed relationship between these decadal changes and the increased eutrophication over recent decades are worth further study.     

地理国情监测地表覆盖分类成果复核的质量分析

针对地理国情监测成果质量复核中如何科学、客观地检查和评价地表覆盖分类成果,使成果复核在质量控制中起到关键作用,基于地理国情监测地表覆盖分类成果特点,通过在成果验收基础上开展针对成果重要质量元素、重点内容的复核检查,以保证全国成果质量的一致性和符合性.本文提出了复核内容与方法,统计从开展成果复核起历年结果表明,分类精度不仅是地表覆盖分类成果质量的控制难点也是短板.通过归纳复核发现的地表覆盖分类成果主要问题,分析产生的原因,为监测生产提出了意见建议.     

山东中西部后向发展雷暴初步研究

基于山东济南新一代天气雷达多年资料,首先提出后向发展雷暴的概念,并规定了普查标准。通过普查2005—2012年8年济南多普勒天气雷达资料,选取了75个后向发展雷暴个例,分析了山东中西部后向发展雷暴的统计特征,给出了常见的3种后向发展雷暴概念模型。选取典型个例,分别对3种类型后向发展雷暴的演变方式及其物理机制进行了初步分析,为山东中西部后向发展雷暴的生成和演变提供了初步的认识。结果表明:(1)后向发展雷暴主回波以带状为主,生命史1—5 h,最大反射率因子在50 dBz以上,移动路径有西—西北、西南、原地新生3种类型;(2)新回波初生时间发生在16—17时(北京时)最多,初生地点在鲁西北和鲁中山区一带,强度一般在30 min内超过40 dBz,生命史在1 h以上,74.7%的新生回波与主回波合并或连接;(3)山东省中西部具有后向发展特征的对流系统产生的灾害性天气以冰雹和雷暴大风为主,很少伴随暴雨灾害;(4)新回波的源地特征可以分为随主回波移动、沿同一方向延伸以及位于两雷暴群之间3种类型;多个雷暴群共存时,新回波的源地介于两个回波带之间,使二者逐渐趋为一体;(5)当主回波传播方向与其长轴相交时,其长轴方向转向,距离新回波较远的一侧减弱;当主回波传播方向与其长轴方向一致,新回波源地位于主回波长轴的延长线上时,主回波加强;(6)天气尺度系统为后向发展雷暴提供了条件不稳定的大气层结和丰富的水汽,地面辐合线和冷池前沿阵风锋是产生新雷暴的主要抬升触发机制;适当的低层垂直风切变有利于新雷暴持续产生并加强;地形的阻挡使新回波源地在同一地点停滞,冷池阵风锋在低层风引导下沿地形向下游移动,新回波源地也随之移动。     

西藏念青唐古拉山帕戈勒中新世二云母花岗岩成因机制及对稀有金属铍成矿能力的指示

淡色花岗岩是研究浅部地壳物质成分和碰撞造山带地球动力学过程的理想对象,也是稀有金属成矿的重要载体。本文研究的帕戈勒二云母花岗岩发育在西藏冈底斯念青唐古拉复式花岗岩岩基的西南侧,以岩株和岩枝形式产出,局部偶见绿柱石。精细的锆石U-Pb定年显示,岩体结晶成岩年龄为18.4 Ma和17.6 Ma,形成于中新世。岩体具有高的SiO₂(72.78%～75.53%)和K₂O(4.83%～5.52%)含量,低的Al₂O₃(13.42%～14.60%)、MgO(0.10%～0.24%)、TFe₂O₃(0.86%～1.65%)含量,A/CNK为1.04～1.12,属于过铝质高钾钙碱性-钾玄质花岗岩。(⁸⁷Sr/⁸⁶Sr)_i=0.712139～0.713545,ε_Nd(t)=-9.0～-8.3,Nd二阶段模式年龄t_DM2=1211～1468 Ma,²⁰⁶     

中国海及邻区盆地现今地温场特征及其影响因素

现今地温场是构造活动、岩石圈热状态的综合反应,对研究盆地的区域构造演化、深部岩石圈结构和评估油气潜力具有重要意义。地温梯度和大地热流是表征沉积盆地热状况的两个基本参数。虽然我国大陆地区地热数据较丰富,并已经过四次系统汇编,但中国海及邻区盆地地热数据报道较少,且未经过系统整理。本文基于近年来新增的钻井温度数据,新增计算研究区810个地温梯度数据,并收集了国内外数据库、期刊的地热数据,在此基础上,首次系统整理了中国海及邻区盆地地温梯度数据和大地热流数据,绘制了其等值线图,分析了研究区现今地温场特征并讨论了其影响因素。研究结果表明,中国海及邻区盆地平均地温梯度43.2±25.7℃/km,平均大地热流74.4±26.6 mW/m²,多数盆地平均大地热流高于65 mW/m²,属于“热盆”;地温场分布总体呈现较为明显的“两带性”,其中近岸带较冷,远岸带较热;研究区现今地温场特征直接或间接地受控于其所处的构造环境,整体上是太平洋板块等多板块作用下岩石圈伸展减薄的结果,局部地区的热异常可能与断裂活动、岩浆活动、泥-热流底辟活动等因素有关。     

Comprehensive diag”nostic review of the (13)~C-enriched crude oils exemplified by TD2∈ and TZ62S in Tarim Basin,NW China

The crude oils typically from the CambrianLower Ordovician source rocks of Tarim Basin, NW"China, such as TD2 and TZ62S, are13C-enriched with the stable carbon isotopic ratios(VPDB) approaching-28 %.In this paper, the main research viewpoints on this issue are summarized, and combined with results from organic and inorganic carbon isotope stratum curves of the outcrop at the Ya’erdang Mountain in Tarim Basin. In addition, more alternative interpretations are discussed. On one hand, the inverse fractionation features of stable carbon and hydrogen isotopes of these crude oils may imply their protogenous nature. On the other hand, the anisotropy of source rocks and contribution from older stratum source rocks need verifying as well. For the sake of the final resolution of this issue, some further study topics are recommended.     

浅析全数字测图方法在高精度多要素地形图测量中的应用

全数字测图有高精度、速度快、内外业一体化作业的优势,近年来随着GPS、GIS技术的发展,全数字测图又得到了迅速地发展与应用。在多要素地形图测量中,全数字测图的优势得到了充分地发挥。结合某研究院科研区大比例尺地形图测绘实例介绍了切实应用的几种测量方法,为相似工程提供参考。