近期地面运动关系之间的某些比较

对最近５ａ新提出的北美东部的地面运动关系进行了研究,将Ａｔｋｉｎｓｏｎ和Ｂｏｏｒｅ（１９９５）的经验－随机关系,由电力研究所（ＥＰＲＩ,１９９３;Ｔｏｒｏｅｔａｌ。,１９９４）、Ｆｒａｎｋｅｌ等（１９９６）研究得出的关系,及由ＳＳＨＡＣ（１９９６）公布的北美东部标准地面运动数值作了比较。我们与ＥＰＲＩ或Ｆｒａｎｋｅ的关系之间存在的主要差别表现在低频振幅上。应用我们的经验震源模型,在１Ｈｚ处得出的振     

临震前震：b值的时间变化

对前震和长期地震活动在频度－震级关系式中的ｂ值做了比较。研究了发生在主震前两个非重叠时间内隔内的前震：（１）数小时内;（２）数天内。区域的和全球的地震目录统计分析表明,这些间隔内的ｂ值比长期地震活动的ｂ值下降了一半。这扩展了Ｍｏｌｃｈａｎｔ和Ｄｍｉｔｒｉｅｖａ先前的研究结果,他们发现在主震前数小时内出现了这样的下降。我们的结果是个统计性的规律,未必在每一单个前震序列中都能出现。     

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, we report on the first year-round observations available for any site in Taylor Valley. This dataset augments the year-round data obtained at Lake Vanda (Wright Valley) by winter-over crews during the late 1960s and early 1970s. The mean annual solar flux at Lake Hoare was 92 W m-2 during 1986, the mean air temperature -17.3 degrees C, and the mean 3-m wind speed 3.3 m s-1. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year. Temperature increases of 20 degrees-30 degrees C are frequently observed during the winter due to strong f?hn winds descending from the Polar Plateau. A model incorporating nonsteady molecular diffusion into Kolmogorov-scale eddies in the interfacial layer and similarity-theory flux-profiles in the surface sublayer, is used to determine the rate of ice sublimation from the acquired meteorological data. Despite the frequent occurrence of strong winter f?hns, the bulk of the annual ablation occurs during the summer due to elevated temperatures and persistent moderate winds. The annual ablation from Lake Hoare is estimated to have been 35.0 +/- 6.3 cm for 1986.     

High-resolution slug testing

The hydraulic conductivity (K) variation has important ramifications for ground water flow and the transport of contaminants in ground water. The delineation of the nature of that variation can be critical to complete characterization of a site and the planning of effective and efficient remedial measures. Site-specific features (such as high-conductivity zones) need to be quantified. Our alluvial field site in the Kansas River valley exhibits spatial variability, very high conductivities, and nonlinear behavior for slug tests in the sand and gravel aquifer. High-resolution, multilevel slug tests have been performed in a number of wells that are fully screened. A general nonlinear model based on the Navier-Stokes equation, nonlinear frictional loss, non-Darcian flow, acceleration effects, radius changes in the wellbore, and a Hvorslev model for the aquifer has been used to analyze the data, employing an automated processing system that runs within the Excel spreadsheet program. It is concluded that slug tests can provide the necessary data to identify the nature of both horizontal and vertical K variation in an aquifer and that improved delineation or higher resolution of K structure is possible with shorter test intervals. The gradation into zones of higher conductivity is sharper than seen previously, and the maximum conductivity observed is greater than previously measured. However, data from this project indicate that well development, the presence of fines, and the antecedent history of the well are important interrelated factors in regard to slug-test response and can prevent obtaining consistent results in some cases.     

Biomarker responses in pelagic and benthic fish over 1 year following the Hebei Spirit oil spill (Taean, Korea)

After the Hebei Spirit oil spill incident (7th December, 2007) in the west coast of Korea, contamination of biliary PAH metabolite and hepatic biomarkers in a pelagic and a benthic fish was monitored for 1 year. Concentrations of 16 PAHs and alkylated PAHs in fish muscle were highest (22.0 ng/g d.w. for 16 PAHs and 284 ng/g d.w. for alkylated PAHs) at 5 days after the spill and then decreased rapidly to background levels at 11 months after the spill. Fish from the oiled site had elevated biliary PAH metabolite concentrations immediately after the spill; these declined steadily in both species, but were still above reference site concentrations 2 months after the spill. Oiled-site fish showed hepatic CYP 1A induction whose trend closely followed those of biliary PAH metabolite concentrations, implying continuous exposure to PAHs. Brain acetylcholinesterase activity was not related to oil exposure.     

地质学家探测加拿大西部克拉通

前寒武纪克拉通保存了南地演化过程的重要线索,然而,目前对显生宙沉积物之下的广大克拉通地区的未进行过科学探测,加拿大岩石圈探测工程艾伯塔底断面项目（ＡＢＴ）的地质学家们正在研究加拿西部富含石油的沉积盆地（ＷＣＳＢ）的演化。他们通过多种技术手段来分析沉积盆地内的特征,并解释下部前寒武纪地壳和上地幔的成因,这项工作提供了北美克拉通重要的未知部分的新看法。地震波反射测量揭示了由古老侵蚀山带组成的年代为１．     

Organochlorine contaminant exposure and associations with hematological and humoral immune functional assays with dam age as a factor in free-ranging northern fur seal pups (Callorhinus ursinus)

Potential effects of organochlorine contaminant (OC) exposure on humoral immune function and health of free-ranging northern fur seals were investigated. Forty-two "neonates" were captured for blood sample collection and re-sampled as "pups" 29-51 days later. OCs were extracted from whole blood to identify polychlorinated biphenyl congeners and chlorinated pesticides by high performance liquid chromatography. Humoral immune function was assessed by antibody responses to vaccination and immunoglobulin concentrations. Additional health status indicators included leukocyte counts and haptoglobin concentrations. Mean OC concentrations were higher in neonates than at recapture. Neonates of young dams had higher mean OC concentrations than neonates of older dams. A higher proportion of old dam's pups developed a twofold or greater increase in antigen-specific antibodies compared to young dam's pups. Higher OC exposure and poor immune responses in first-born pups may indicate a higher risk of secondary morbidity and mortality than pups of multiparous dams.     

Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States

Background  

Standing dead trees are one component of forest ecosystem dead wood carbon (C) pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates) began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales.     

一种低海平面时期的沉积岩相——深水盆地相碳酸盐砾岩层序

作者认为北美阿巴拉契亚地区和我国贺兰山地区奥陶系的一套碳酸盐砾岩层序,就是低海平面时期的一种特殊沉积岩相。这种岩相不仅是古海洋条件变化的一种标志,而且也是良好的油气储集层。文中主要从沉积学的角度解释了它们的形成机制。     

构造样式的演化：来自加拿大地盾早元古代盆地的证据

近几年来,人们正逐渐趋向于用板块构造的概念来解释早元古代盆地的成因。加拿大地盾早元古代的典型层序为位于休伦湖北岸的休伦超组、休伦组(厚度达12km)不整合于太古宙基底岩石之上,在某些地带二者被一古土壤层分开。休伦组的下部主要由河成陆源碎屑岩组成,伴生有火山碎屑岩及浊积岩和化学沉积岩(白云岩和石灰岩),该组下部产有冰碛岩。这些岩石分布局限并具有一定的岩相特点,认为是形成于裂谷环境。与此相反,休伦组的上部分布广汇,主要由浅海相岩石组成,认为是被动大陆边缘的一个台楔或mioclinal沉积。Mioclinal层序的基底冰积岩(Gowganda组)发育。苏比利尔湖地区早元古代层序的下部(Miocolay组和Mille Llacs组)可与休伦超组的上部