作为自组织格局的滩角

对海滩冲流带内的流与泥沙输运的计算机模拟表明,一个将局部流加速与沿岸水面梯度结合的模型足以形成均匀间距的滩角。模拟的滩角特征及其形成的条件与观测的自然滩角状况吻合良好。模型中的自组织机制与一个已被接受的孤立波模型不同,在孤立波模型中沿岸孤立波产生规则的侵蚀和淤积模式从而形成滩角。由于这两个模型给出类似的预测,目前所具有的观测数据不足以将它们区分开。     

GEOBAROMETRIC CONSTRAINTS ON THE DEPTH OF EMPLACEMENT OF GRANITE FROM THE LADAKH BATHOLITH, NORTHWEST HIMALAYA, INDIA

GEOBAROMETRIC CONSTRAINTS ON THE DEPTH OF EMPLACEMENT OF GRANITE FROM THE LADAKH BATHOLITH, NORTHWEST HIMALAYA, INDIA1　BlundyJD ,HollandTJB .Calcicamphiboleequilibriaandanewamphibole plagioclasegeothermometer[J] .ContribMiner alPetrol,1990 ,10 4 :2 0 8～ 2 2 4 . 2　SchmidtMW .Amphibolecompositionintonaliteasafunctionofpressure:anexperimentalcalibrationoftheAl inhorn blendebarometer[J] .ContribMineralPetrol,1992 ,110 :30 4～ 310 . 3　Th…     

Two Phases of Cenozoic Deformation in Northeastern Tibet: Thrusting Followed by Strike-Slip Faulting

TWO PHASES OF CENOZOIC DEFORMATION IN NORTHEASTERN TIBET: THRUSTING FOLLOWED BY STRIKE-SLIP FAULTING     

内核地震波速各向异性的成因

地球内核是轴对称各向异性的,其对称轴与地球的极轴之间有１１°左右的夹角,本 文根据地球内核相对于外部地球有差异转动这一观测结果,利用晶体生长理论,对内核地震波 速度各向异性的成因进行了探讨．当从熔融状态结晶时,晶体的生长速度与晶体和熔融态之 间相对运动的线速度成正比涸此当固态内核在液态外核中生长时,沿赤道方向的生长速度比 两极方向快．在万有引力场的作用下内核始终保持近似球形,生长速度较快的赤道附近的物 质会向两极区域流动,形成轴对称的流变场。这一轴对称的流变场伴随着轴对称的应力场,使 得构成地球内核的ｈｃｐ型铁晶体的ｃ轴沿着内核自转轴的方向排列,导致观测到的地球内核地 震波速度各向异性。作为推论,内核相对于外部地球可能同时存在着进动和章动。     

利用经验线方法校准ASTER和ETM+影像——以也门Hajjah东北部为例(英文)

This study is aimed at using the Empirical Line Method (ELM) to eliminate atmospheric effects with respect to visible and near infrared bands of advanced spaceborne thermal emission and reflection radiometer (ASTER) and enhanced thematic mapper plus (ETM+) data. Two targets (Amran limestone as light target and quartz-biotite-sericite-graphite schists as dark target), which were widely exposed and easy to identify in the imagery were selected. The accuracy of the atmos-pheric correction method was evaluated ...     

全球热液场的分布

不考虑图9中的快速洋脊与慢速洋脊之间的基本特征,δ（3He％）的分布更为复杂。沿着东太平洋快速扩张洋脊,δ（3He％）值显示出不连续的高值,而不是相对扩张速率显示出均一的分布。而没有想到的是低值区出现在从印度洋三联点到东太平洋洋隆一智利洋隆三联点处。     

利用多种测井数据估算阿拉斯加北部陆坡Mount Elbert井原位气体水合物饱和度

2006年,美国地质调查局（USGS）完成了对可用的2D和3D地震数据的解释和分析后,提出了一个确定阿拉斯加北部Milne Point区域永冻带下气体水合物稳定带内的水合物矿藏的可行办法。为了验证USGS的预测并获得关键的储层数据,也是为了形成长期生产测试计划发展的需要,2007年2月,在Mount Elbert矿区进行的钻井取得了多种测井数据和岩芯数据,并将这些数据用来估算水合物原位饱和度及储层属性。气体水合物饱和度可根据不同的测井数据估算,如核磁共振（NMR）,P波与S波速度,电阻率以及孔隙水盐度等。根据NMR测井数据估算的气体水合物饱和度与通过P波和S波估算的结果非常吻合。由于原生水的低盐度及低的形成温度,原生水的电阻率与页岩的电阻率是相当的,因此在利用电阻率测井数据准确估算气体水合物饱和度时,必需解决粘土的影响。确定二个气体水合物高饱和区段,上部区段的厚度约43ft,平均气体水合物饱和度为54％,下部区段厚度53ft,平均气体水合物饱和度为50％,二个区段的最大饱和度都达到75％。     

蛇绿岩铬铁矿成矿新模型:流体不混溶作用

尽管富水流体参与蛇绿岩豆英状铬铁矿形成过程已被广泛提及,但流体的作用和机制仍缺乏天然样品的证据证实.文章对保存完好的土耳其Kizilda(g)蛇绿岩和研究程度较高的西藏罗布莎蛇绿岩的铬铁矿床进行了岩石学、矿物学和地球化学的系统总结,展示了流体活动的证据,探讨了铬铁矿结晶与岩浆演化过程中流体不混溶的关系,进而建立了铬铁矿...     

A New Troodontid Dinosaur from the Lower Cretaceous Yixian Formation of Liaoning Province, China

A new troodontid dinosaur,Daliansaurus liaoningensis gen.et sp.nov.,is erected based on a nearly complete specimen from the Lower Cretaceous Yixian Formation of Beipiao City,Liaoning Province,China.This well preserved skeleton provides important new details of the anatomy for Liaoning troodontids,and gives new insight into their phylogenetic relationships and evolution.Daliansaurus is distinguished from other troodontids by an enlarged ungual on pedal digit IV,which is approximately the same size as the sickle-shaped second ungual,and is differentiated from other Liaoning troodontids by a number of characters of the skull,manus,pelvis,and hindlimb.A phylogenetic analysis recovers Daliansaurus within a subclade of Liaoning troodontids that also includes Sinovenator,Sinusonasus,and Mei.We erect a name for this group—Sinovenatorinae—and argue that it reflects a localized radiation of small-bodied troodontids in the Early Cretaceous of eastern Asia,similar to previously recognized radiations of Liaoning dromaeosaurids and avialans.As more Liaoning theropods are discovered,it is becoming apparent that small,feathered paravians were particularly diverse during the Early Cretaceous,and future work is needed to clarify how this diversity arose,which species coexisted,and how these numerous species partitioned niches.     

Climate Changes in the 21st Century over the Asia-Pacific Region Simulated by the NCAR CSM and PCM

The Climate System Model (CSM) and the Parallel Climate Model (PCM), two coupled global climate models without flux adjustments recently developed at NCAR, were used to simulate the 20th century climate using historical greenhouse gas and sulfate aerosol forcing. These simulations were extended through the 21st century under two newly developed scenarios, a business-as-usual case (BAU, CO2≈710 ppmv in 2100) and a CO2 stabilization case (STA550, CO2≈540 ppmv in 2100). The simulated changes in temperature, precipitation, and soil moisture over the Asia-Pacific region (10°-60°N, 55°-155°E) are analyzed, with a focus on the East Asian summer monsoon rainfall and climate changes over the upper reaches of the Yangtze River. Under the BAU scenario, both the models produce surface warming of about 3-5℃ in winter and 2-3℃ in summer over most Asia. Under the STA550 scenario, the warming is reduced by 0.5-1.0℃ in winter and by 0.5℃ in summer. The warming is fairly uniform at the low latitudes and does not induce significant changes in the zonal mean Hadley circulation over the Asia-Pacific do main. While the regional precipitation changes from single CSM integrations are noisy, the PCM ensemble mean precipitation shows 10%-30% increases north of ～ 30°N and ～ 10% decreases south of ～ 30°N over the Asia-Pacific region in winter and 10%-20% increases in summer precipitation over most of the region. Soil moisture changes are small over most Asia. The CSM single simulation suggests a 30% increase in river runoff into the Three Gorges Dam, but the PCM ensemble simulations show small changes in the runoff.