Decoupling of stalagmite-derived Asian summer monsoon records from North Atlantic temperature change during marine oxygen isotope stage 5d

The Asian monsoon is an important component of the global climate system. Seasonal variations in wind, rainfall, and temperature associated with the Asian monsoon systems affect a vast expanse of tropical and subtropical Asia. Speleothem-derived summer monsoon variation in East Asia was previously found to be closely associated with millennial-scale change in temperature in the North Atlantic region between 75 and 10 ka. New evidence recovered from East Asia, however, suggests that the teleconnection between summer monsoon in East Asia and temperature change in the North Atlantic region may have significantly reduced during 120 to ~ 110 ka, a period directly after the full last interglaciation and corresponding roughly to marine oxygen isotope stage 5d. This reduction may be due to the low ice volume in the North Hemisphere at that time, which makes the millennial-scale change in temperature in the North Atlantic region less effective in influencing the Asian summer monsoon. This is important for investigating the mechanisms controlling the Asian summer monsoon and the paleoclimatic teleconnection between East Asia and the North Atlantic region, and for predicting monsoon-associated precipitation in East Asia under a global-warming trend.     

构造地质学计算机辅助教学课件SGCAI

构造地质学计算机辅助教学课件（ＳＧＣＡＩ）利用数据库，图形动画及多媒体等技术，对地质学基础课程的计算机辅助教学研究作了初步探索，课件分为学生学习，教师管理，附属功能和执行四大模块，具有学习选择，图片说明，动画演示，练习测验，辅导答题等十个功能，课件设计新颖，技术全面，使用方便，使用该课件能充分调动学生学习的主观能动性，使学生成为真正的学习主体，有助于提高教学质量。     

Inertial instability of large Rossby number horizontal shear flows in a thin homogeneous layer

A horizontal shear flow having a Rossby number, Ro, greater than unity on a rotating plane can become unstable when its shear value is less than −f, the Coriolis frequency. In this paper, this instability is investigated for an O(10 km) submesoscale, sinusoidal shear flow in a thin homogeneous fluid layer as in an oceanic mixed layer or a shallow sea. The most unstable mode is shown by a linear analysis to occur in a narrow localized region centered around the maximum anticyclonic current shear. However, nonlinear numerical calculations show that the instability can grow to encompass both unstable and stable regions of the current. A consequence of this finite-amplitude evolution is the formation of surface convergence/shear fronts. The possibility that inertial instability mechanism is a source of some surface convergence/shear features seen in remote sensing images of the sea surface is discussed. A comparison is made with the shear-flow instability that can occur concurrently in a sinusoidal shear current, and inertial instability is shown to be the dominant instability mechanism in the immediate range above Ro=2.     

Ammonia adsorption and nitritation in sediments derived from the Three Gorges Reservoir,China

The influences of suspended particles (SPs) on NH₄ ⁺ adsorption and nitritation occurring in the water system of the Three Gorges Reservoir (TGR) were evaluated in this study. The results indicated that the adsorption of NH₄ ⁺ was significantly affected by the SPs concentration under the conditions typically present in the TGR. The amount of ammonia adsorbed per unit weight of suspended particles was inverse proportional to the concentration of suspended particles. However, the influences of the particle size and the organic matter concentration existing in SPs were insignificant under the experimental conditions. The effects of suspended particles on nitritation were determined by the use of ammonia-oxidizing bacteria (AOB) strain SW16, identified as Nitrosomonas nitrosa, which was isolated from sediment samples of the TGR. Suspended particle concentration in water–sediment solution played an important role in the nitritation process. The rate of nitritation enhanced with the increase of the suspended particle concentration. It was found that the critical factor controlling ammonia oxidizing rate was the AOB biomass resulting from the AOB growth rate. Moreover, results demonstrated that both particle size and organic matter content showed little effect on the nitritation process under the experimental conditions.     

塔里木盆地晚泥盆世-早石炭世东河砂岩沉积相

东河砂岩是塔里木盆地主要的勘探目的层和产油层之一。经过多年艰苦勘探和多学科综合研究,现已认识到东河砂岩为晚泥盆世晚期至早石炭世早期海平面上升背景下沉积的一套海侵底砂（砾）岩,在盆地范围内是一个明显的穿时沉积体。东河砂岩以滨浅海相陆源碎屑沉积占优势,局部发育海陆过渡相陆源碎屑沉积。根据盆地内100多口井资料的岩石学特征、沉积特征以及其它指相标志的综合分析,在东河砂岩中识别出滨岸、河口湾、辫状河三角洲以及冲积扇等不同的沉积相类型,其中高能碎屑滨岸相最重要,分布最广。东河砂岩沉积早期和中期,盆地主要为高能碎屑滨岸相和碎屑陆棚相沉积,末期海侵达到最大,盆地内为碳酸盐台地沉积,而轮南及盆地北部一带受物源区的影响,出现混积滨岸和碎屑滨岸沉积。东河砂岩明显具有填平补齐的沉积特征,其砂体厚度在缓坡处减薄、陡坡处增厚、遇孤岛减薄或尖灭,这些沉积特征为形成东河砂岩非构造圈闭奠定了良好的地质基础。满加尔、轮南、塔中、玛扎塔格以及草湖地区都有可能找到该类油气藏（田）,展示了东河砂岩非构造圈闭的良好勘探前景。     

华南区域季节性降水的差异分析

运用EOF方法研究华南区域降水时空分布特征,结果表明：（1）华南地区各季节降水在年际和年代际的时间变化上有区域一致性,但有季节性差异,其中春季和秋季在20世纪80年代后降水明显减少,旱年增多;而夏季90年代后降水明显增加,涝年增多;冬季变化则不明显。（2）华南地区各季节降水在空间分布上也有差异,其中春季降水呈现东多西少的分布特征,大值中心位于广西东北部、广东中部及西南沿海。夏季和秋季降水相似,呈南多北少的分布特征,大值中心位于广西沿海和广东西南沿海。冬季降水呈东北多西南少的分布特征,大值中心位于粤北。     

南大洋海冰影像地图投影变换与瓦片切割应用研究

南大洋海冰分布是南极考察过程中影响破冰船航行的重要因素,也是南极研究的重要内容之一。目前国际上不同机构发布的南大洋海冰分布图,大多是球面投影,不能直接用于主流的瓦片地图发布。将极方位立体投影海冰图转换为目前主流的网络墨卡托投影地图,并利用合适的图像重采样方法,按照不同级别比例尺进行瓦片切割和编号存储,最终实现海冰影像地图的发布共享是本文的主要研究内容。笔者对不同的图像重采样方法进行了比较,分析了最邻近点采样方法、双线性内插和双三次卷积重采样方法的优劣,针对本文的研究优选双线性内插方法进行影像地图瓦片的切割,并最终叠加融合在Google地图上,实现了Google底图、准实时海冰影像图与破冰船走航位置的集成显示,为雪龙船的冰区航行提供了重要的数据支撑。     

大中小震与抗震设防标准

讨论二级抗震设计与超越概率标准、概率法与综合概率法给出的3个水平的地震动的关系. 通过危险性分析的实际例子,讨论了50年超越概率2%、10%和63%的地震动,即大震、中震和小震的相对大小关系,并提出抗震设防标准的确定方法.     

塔里木盆地牙哈-英买力地区寒武系-奥陶系碳酸盐岩储层成因类型、特征及油气勘探潜力

牙哈—英买力地区是塔北隆起上的主要油气富集区,古潜山风化壳型储层的观点一直主导着该地区寒武系—奥陶系碳酸盐岩油气勘探的思路。但储层精细描述揭示了牙哈—英买力地区除古潜山风化壳型储层外,还发育有暴露浅滩型、层间古岩溶型、白云岩型储层。其中位于古潜山面之下经风化作用改造的白云岩型储层是最有勘探价值的,勘探成功率高。其次是暴露浅滩型储层,油藏类型有早成藏残留型和晚成藏型。暴露浅滩型、层间古岩溶型和白云岩型储层也是很有勘探价值的储层类型。早成藏型原生油气藏,位于寒武系—奥陶系与志留系呈假整合接触的地区,与古潜山无关。古潜山风化壳型储层可以形成晚成藏型油气藏,但目前试油结果均为水层,值得进一步探索。     

��̬������С����ģ�͵������㷨

????????????????????????????????????????????????????С????????в???????,?????????????С???????????????????????????????????Tikhonov?????????????????????С??????????????????????????????????????????????Э????????????????????Fredholm???????????????????????????С????????????????????? ???????????????????????й?????????????????????????????