11月气候异常型及前期环流信号

利用全国160站1951—2008年11月温度、降水资料和同期秋季NCEP/NCAR 500 hPa高度场再分析资料,分析了我国东部季风区11月暖湿、暖干、冷湿、冷干年同期环流特征,并对同期、前期环流特征进行了差异t检验。结果表明:暖型 (冷型) 同期环流对应乌拉尔山阻塞高压不明显 (明显),欧亚中高纬度地区盛行纬向 (经向) 环流;干型 (湿型) 同期环流对应西太平洋副热带高压偏弱 (强)、偏东 (西)。差异t检验分布特征表明:在亚洲中高纬度地区,暖干、冷湿型 (暖湿、冷干型) 同期环流主要表现为南北 (东西) 气压场的差异;暖干、冷湿型的前期和同期环流特征分别具有EU (Eurasia) 和反EU遥相关距平结构,而暖湿、冷干型前期和同期环流特征分别具有反PNA (Pacific/North American) 和PNA遥相关距平结构。     

A study of partitioning Q vector on background conditions of a torrential rainfall over Shanghai, China on 25 August 2008

A rainfall that occurred during 0200–1400 Beijing Standard Time(BST)25 August 2008 shows the rapid development of a convective system,a short life span,and a record rate of 117.5 mm h-1for Xujiahui station since 1872.To study this torrential rainfall process,the partitioning method of Q vector is developed,in which a moist Q vector is first separated into a dry ageostrophic Q vector(DQ)and a diabatic-heating component.The dry ageostrophic Q vector is further partitioned along isothermal lines in the natural...     

铼-锇同位素分析样品预处理研究进展

文章评述并归纳了近年来地质样品中Re-Os同位素分析的化学前处理方法研究进展。总结了锍镍火试金法、碱熔法、Carius管溶样法以及HPA-S高温高压釜溶样法等常用的Re-Os同位素样品消解方法。归纳了离子交换、溶剂萃取富集Re以及蒸馏、萃取等分离富集Os的方法。由于地质样品的复杂性,Re、Os含量的不均一性及测试方法的多样性,要求在具体分析过程中不同的样品使用不同的消解方法和分离富集方法。当前国内应用较成熟的Re、Os分离方法是Carius管逆王水分解样品,原位蒸馏或CCl4萃取方法分离Os,阴离子交换法或丙酮萃取分离Re。     

融沉系数的人工神经网络预测方法

分析了前人关于融沉系数经验方法的研究结果,结果显示,与融沉系数关系最为密切的物性参数为液塑限、粉黏粒含量、干密度和含水量（含冰量）．为了能够综合描述诸因素与融沉系数的经验关系,以兰州黄土和青藏黏土为试验对象,得到了两种具有不同物性参数的土在不同含水量和干密度条件下的融沉系数．采用BP神经网络算法对试验数据进行学习训练,...     

流域植被对径流调节作用的实验研究

根据河北省邢台市西部山区两个小流域实验站的水文监测资料,研究了不同流域内的不同植被对径流的影响。分析了流域植被对径流的年内分配、径流系数、削减洪峰以及枯季径流量等的影响。结果表明,流域植被对涵养水源、调节径流量、增大枯季径流量起到重要作用。     

Different characteristics of the structure of atmospheric boundary layer between dry and rainy periods over the northern Tibetan Plateau

In this paper, based on in-situ observational data of the Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau (CAMP-Tibet), structure of the Atmospheric Boundary Layer (ABL) was preliminarily studied during the dry and rainy seasons. The main results show: (a) Diurnal variation of the ABL is obvious over the northern Tibetan Plateau area. The height of the ABL is different with the season change, which ranges from 2,211 m to 4,430 m during the pre-monsoon season and from 1,006 m to 2,212 m during the monsoon season. The ABL height is higher during the dry period than during the rainy period. (b) The humidity is lower during the dry period than during the rainy period, and there are reverse humidity during both periods. (c) Horizontal wind direction is mostly west during the dry period, east under the height of 2,500 m and west above the height of 2,500 m during the rainy period. The wind speed is low during both the rainy and dry periods in the lower ABL layer. The wind speed is stronger within the upper ABL during the dry period than during the rainy period.     

Reappraisal of the 1982 eruptions of El Chichón Volcano, Chiapas, Mexico: new data from proximal deposits

 Additional data from proximal areas enable a reconstruction of the stratigraphy and the eruptive chronology of phases III and IV of the 1982 eruption of El Chichón Volcano. Phase III began on 4 April at 0135 GMT with a powerful hydromagmatic explosion that generated radially fast-moving (∼100 ms^–1) pyroclastic clouds that produced a surge deposit (S1). Due to the sudden reduction in the confining pressure the process continued by tapping of magma from a deeper source, causing a new explosion. The ejected juvenile material mixed with large amounts of fragmented dome and wall rock, which were dispersed laterally in several pulses as lithic-rich block-and-ash flow (F1). Partial evacuation of juvenile material from the magmatic system prompted the entrance of external water to generate a series of hydromagmatic explosions that dispersed moisture-rich surge clouds and small-volume block-and-ash flows (IU) up to distances of 3 km from the crater. The eruption continued by further decompression of the magmatic system, with the ensuing emission of smaller amounts of gas-rich magma which, with the strong erosion of the volcanic conduit, formed a lithic-rich Plinian column that deposited fallout layer B. Associated with the widening of the vent, an increase in the effective density of the uprising column took place, causing its collapse. Block-and-ash flows arising from the column collapse traveled along valleys as a dense laminar flow (F2). In some places, flow regime changes due to topographic obstacles promoted transformation into a turbulent surge (S2) which attained minimum velocities of approximately 77 ms^–1 near the volcano. The process continued with the formation of a new column on 4 April at 1135 GMT (phase IV) that emplaced fall deposit C and was followed by hydromagmatic explosions which produced pyroclastic surges (S3). Received: 13 May 1996 / Accepted: 12 November 1996     

用GPS监测城市地面沉降的可行性研究

研究了用GPS观测取代常规水准测量方法监测城市地面沉降变化的可行性。在宁波市进行了两期GPS测量和水准测量，观测中并采取一定的措施以获得高精度的高程分量。顾及到对流层延迟的影响，采用Saastamcinen模型改正对流层延迟的干分量部分，用分段线性方法来估计对流层的湿分量变化。用Bernese软件对数据进行处理，获得了毫米级的高程精度。实际算例证明，用GPS测量代替水准测量来监测城市地面沉降变化是可行的。     

半干旱及大温差环境下水泥稳定碎石变形试验

为研究水稳基层变形影响因素,对水泥剂量、品种、级配设计等方面展开系统试验研究。本文对骨架密实型水泥稳定碎石、悬浮密实型水泥稳定碎石和骨架空隙型水泥稳定碎石进行干缩试验及温缩试验,运用Origin对试验数据进行回归拟合,总结半刚性基层材料的变形规律,从而提高沥青路面的耐久性。结果表明：对比结构类型不同的水泥碎石材料可知,骨架空隙型干缩系数0~7 d增大了2倍,后续干缩系数增幅趋于缓和,在水泥用量相同时,骨架空隙型干燥收缩程度最低,即骨架空隙型结构水泥可有效降低水稳基层开裂;水泥稳定砂砾中,随着水泥用量的增加;各个温度段的温缩变形逐渐增大,并且在高温区50~60℃段温缩变形最大,随着温度降低变形量变小,0~10℃段温缩变形最小;同种水泥剂量、水泥标号中,骨架空隙型平均温缩系数最小,悬浮密实型最大,骨架密实型居中。相同级配、相同水泥剂量的水泥稳定砂砾中,42.5水泥试件平均温缩系数大于32.5水泥试件平均温缩系数。     

干热岩用耐高温钻井液关键技术及进展

干热岩（HDR）是一种可再生绿色清洁能源,其勘探开发具有埋藏深,地层破碎,压力异常,井温梯度高,孔底温度高（通常大于200 ℃）等特点,在钻井过程中易出现钻井液漏失量大,孔壁失稳掉块卡钻等问题。本文通过分析干热岩耐高温钻井液关键技术难点：处理剂及体系抗温问题、起泡问题、漏失、井壁失稳等问题。同时通过对国内外目前干热岩用耐高温钻井液体系进展及应用情况介绍,开展干热岩钻探耐高温钻井液技术发展方向研究,以期对推动我国干热岩资源勘探开发提供有效的技术支撑。