希腊纳克索斯角闪岩相变质作用期间流体的分布和特征

以流体包裹体证据为基础的深部富CO_2流体弥漫性注入模式,已被用来解释纳克索斯岛(希腊基克拉迪)中高级角闪岩相变质作用(M2_B)的成因。本文将讨论矿物脱挥发分作用和熔融平衡原理对该变质杂岩最深出露层次M2_B峰期及其后流体组成的制约作用。结果表明横穿该杂岩的高级变质核。M2_B峰期流体在空间和组成上都表现出非均匀性,且峰期之后的流体通常是富水的。这种蜂期流体成分明显的不均匀性和前人基于流体包裹体证据所得出的CO_2流体弥漫性注入的模式相矛盾。纳克索斯富CO_2流体包裹体中很可能就没有保存峰期变质条件下捕获的流体;也就是说在伴随杂岩抬升所发生的强烈变形作用期间。许多这种包裹体都表现为化学开放体系。类似的过程也可以解释麻粒岩相岩石中出现的某些富CO_2流体包裹体。     

Organochlorine and butyltin residues in deep-sea organisms collected from the western North Pacific,off-Tohoku,Japan

Organochlorine (OCs) and butyltin (BTs) residues were determined in deep-sea organisms collected from the western North Pacific, off-Tohoku, Japan. Among OCs, concentrations of polychlorinated biphenyls (PCBs) and DDTs (DDTs and its metabolites) were the highest in deep-sea organisms (maximum concentrations of 6700 and 13,000 ng/g lipid wt, respectively). Chlordane compounds (CHLs) were the next most abundant OCs, and hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) were the lowest. BTs were also detected at maximum concentrations of 570 ng/g wet wt. Concentrations of PCBs, CHLs and BTs in deep-sea organisms collected from the western North Pacific, off-Tohoku, were generally lower than those in deep-sea and shallow water organisms from Japanese coastal waters. On the other hand, considerable variations in the concentrations of OCs were found among deep-sea organisms analyzed. Several carnivorous fishes such as snubnosed eel, lanternshark and grenadiers accumulated some OCs such as PCBs, DDTs and CHLs at high concentrations of up to a few μg/g levels. In addition, the residue pattern of OCs and BTs in fishes showed a specific trend according to the sampling depth; higher concentrations of PCBs, DDTs and CHLs and lower concentrations of HCHs, HCB and BTs were found in fishes collected from greater depth (1000 m) compared to those from shallower waters. This trend is consistent with the results of our earlier study on mesopelagic myctophid fishes. Results of this study suggest vertical transport of hydrophobic OCs such as PCBs, DDTs and CHLs and its accumulation in benthic deep-sea organisms.     

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.     

安阳两次连续性暴雨过程对比分析

对2001年7月26～28日、1994年6月23～25日安阳区域连续性暴雨过程的环流形势场与物理量分析结果表明：高低空西南急流与中尺度气旋的相互作用,是形成连续性强降水的一个重要机制;中尺度的动力、热力特征是强降水维持的原因.     

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.     

An ensemble forecast of the South China Sea monsoon

1.IntroductionThispaperexploresanensembleforecaststrategyforthelarge--scaletropicalpredictionproblem.Thisisgeneralizedfromarecentstudyontheuseofempiricalorthogonalfunction(EOF)--basedperturbationsforhurricanetrackensembleforecasts,(ZhangandKrishnamur...     

广东韶关梅子冲隐伏-半隐伏银矿地质特征及找矿标志

广东韶关梅子冲银矿为隐伏-半隐伏矿床,前人认为矿体规模小、没有工业开采价值。经研究认为,地表长1300m的物化探异常可能由银铅锌隐伏矿引起,经钻探验证,找到了中型银铅锌多金属矿,矿床有可能扩大为大型规模。