Distribution,sources and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in surface soils of the Yellow River Delta,China

PAH concentrations of 61 surface soil samples collected from the Yellow River Delta (YRD), China were measured to determine occurrence levels, sources, and potential toxicological significance of PAHs. The total concentrations of ∑PAHs ranged from 27 to 753 ng/g d.w., with a mean of 118 ± 132 ng/g. The highest concentrations was found in the mid-southern part of the YRD (753 ng/g), which was associated with the oil exploration. The ratios indicated that the PAHs throughout the YRD were mostly of pyrogenic origin; while various sites in mid-southern part in the region were derived mainly from the petrogenic sources. Multivariate statistical analyses supported that the PAHs in surface soils of the YRD were principally from the coal and biomass combustion, petroleum spills, and/or vehicular emissions. The toxic assessment suggested that the PAHs in soils were at low potential of ecotoxicological contamination level for the YRD.     

福建仙游地震序列的震源机制解

2010年8月4日至2013年10月4日福建仙游共记录到地震1209次,其中最大地震为2013年9月4日发生的ML5.0地震。为了加强对仙游地震序列的研究,更好地了解仙游地震的发震构造及震区的区域应力场,本文利用福建数字地震台网宽频带地震记录,采用矩张量反演方法,得到仙游地震序列中ML3.5的6次地震的震源机制解。这6次地震的震源机制解结果较为一致,都为走滑型地震,断层走向为NW向,倾角陡立,主压应力轴方向为近SN向。反演得到的主压应力轴方向与福建地区的区域应力场并不一致,本文认为仙游地震是由位于震区的金钟水库蓄水造成震区应力调整而引起的。     

临潼-长安断裂带(FN )西段走向研究

临潼-长安断裂是渭河盆地内西安凹陷与骊山凸起的分界断裂,该断裂东北段位置和走向清楚,但西南段(神禾塬以西)的推测走向并无实证资料。在临潼-长安断裂西南方向延伸区域内,通过对3条总长近27km的人工地震勘探剖面解译,发现均存在北倾断裂异常,在其中1处异常布置的地质钻探剖面显示,上更新统和中更新统地层存在错断现象。这些勘探异常点被认为是临潼-长安断裂带中的最北侧断裂FN,其连线基本在1条线上,以大约SW240°的方向,延续了临潼-长安断裂带中段走向,继续向西南方向延伸。     

2010年10月24日周口太康MS4．6地震的震源机制解

利用河南省区域地震台网的近震波形资料,采用近震时间域方法,反演2010年10月24日16点58分太康 MS 4．6地震的地震矩张量,结果显示,该地震为走滑型地震。结合震后灾害考察,认为太康地震发生在周口-太康断裂上。     

气候变化影响和适应认知的演进及对气候政策的影响

通过分析IPCC第二工作组的5次评估报告对气候变化影响、适应的主要结论和方法的演进、原因以及对国际适应谈判和国家适应政策的影响,指出由于文献的迅速增加,影响评估方法和适应技术手段的不断成熟,以及思维的转变和意识的逐渐增强,IPCC进一步确认了气候变化已经并将继续对自然生态系统和人类社会产生广泛而深刻的影响;未来社会经济发展路径、适应和减缓行动以及风险治理将影响气候变化带来的风险。IPCC报告极大地推动了国际和各国适应气候变化科学研究和政策实践的进程。尽管中国各级各部门已逐渐将适应融入到相关政策中,但仍然存在认识、能力、体制机制等问题,需要进一步推进国家和各地的适应工作。     

A model study of the Copper River plume and its effects on the northern Gulf of Alaska

A three-level nested Regional Ocean Modeling System was used to examine the seasonal evolution of the Copper River (CR) plume and how it influences the along- and across-shore transport in the northern Gulf of Alaska (NGoA). A passive tracer was introduced in the model to delineate the growth and decay of the plume and to diagnose the spread of the CR discharge in the shelf, into Prince William Sound (PWS) and offshore. Furthermore, a model experiment with doubled discharge was conducted to investigate potential impacts of accelerated glacier melt in future climate scenarios. The 2010 and 2011 simulation revealed that the upstream (eastward) transport in the NGoA is negligible. About 60 % of the passive tracer released in the CR discharge is transported southwestward on the shelf, while another one third goes into PWS with close to 60 % of which exiting PWS to the shelf from Montague Strait. The rest few percent is transported across the shelf break and exported to the GoA basin. The downstream transport and the transport into PWS are strongly regulated by the downwelling-favorable wind, while the offshore transport is related to the accumulation of plume water in the shelf, frontal instability, and the Alaskan Stream. It takes weeks in spring for the buoyancy to accumulate so that a bulge forms outside of the CR estuary. The absence of strong storms as in the summer of 2010 allows the bulge continue growing to trigger frontal instability. These frontal features can interact with the Alaskan Stream to induce transport pulses across the shelf break. Alternatively as in 2011, a downwelling-favorable wind event in early August (near the peak discharge) accelerates the southwestward coastal current and produces an intense downstream transport event. Both processes result in fast drains of the buoyancy and the plume content, thereby rapid disintegration of the plume in the shelf. The plume in the doubled discharge case can be two to three times in size, which affects not only the magnitude but also the timing of certain transport events. In particular, the offshore transport increases by several folds because the plume appears to be more easily entrained by the seaward flow along the side of Hinchinbrook Canyon.     

考虑发育薄弱区对管涌发展影响的数学模型研究

为了揭示发育薄弱区对管涌发展的影响机制,进行了管涌砂槽模型试验和颗粒流数值模拟,建立了3组模型,以研究孔隙通道的空间发育对颗粒运移过程的影响,分析了土体内部细颗粒运移引起管涌破坏的动态过程。根据数值模拟结果,分析了管涌发展过程中试样细观及流体的变化规律,并与砂槽模型试验结果进行了比较,模拟与模型试验结果较吻合。结果表明,薄弱区越发育,压力分布调整的趋势越强,颗粒运移的趋势相应增加,达到破坏需要的时间越短。数值模拟获得的临界水力梯度与室内试验以及理论分析结果均比较接近,证明了采用颗粒流程序研究管涌问题是合理的,对研究存在薄弱区的砂土管涌现象具有明显的优势和广阔的应用前景。所揭示的结果有益于管涌机制的更深入研究。     

同构造沉积速率对先存被动盐底辟挤压变形的影响:库车坳陷西秋里塔格构造带盐构造分析及物理模拟

文中构建了两组构造物理实验,对存在先存被动盐底辟构造的含盐盆地的厚皮挤压构造演化特征进行模拟,研究揭 示了库车坳陷西段秋里塔格构造带新生代盐相关构造演化过程。实验结果表明,同构造沉积速率对库车坳陷西段秋里塔格 构造带博孜-却勒区域（西段） 和秋里塔格-克拉苏区域（东段） 盐相关构造横向分段差异变形具有重要的控制影响作 用。在挤压过程中,博孜-却勒区域慢速同构造沉积使得先存被动盐底辟北翼（拜城凹陷南翼） 向南逆冲到底辟南翼之 上,并促使却勒盐推覆体和米斯坎塔克盐背斜形成;而秋里塔格-克拉苏区域快速同构造沉积使得先存被动盐底辟北翼快 速下沉,而其南翼在挤压应力作用下向北逆冲到底辟北翼（拜城凹陷南翼） 之上,形成南秋里塔格盐背斜。     

全张量重力梯度数据误差分析及补偿

针对用于航空移动平台的高精度全张量重力梯度测量系统,深入研究了梯度仪12个加速度计按3个不同旋转轴圆盘形成差分组合的结构。在确认该结构具有有效抑制运动共模加速度、减少外界环境干扰、实现高精度探测优点的同时,着重分析了重力梯度仪测量误差的来源和影响。研究表明,主要影响包括仪器固有随机噪声和外界确定性噪声。为定量描述影响程度,推导了在航空动态环境下的测量方程,并分离出加速度计的性能不匹配、平台不稳定、圆盘转速不稳定3个主要固有因素,从时间域和频率域角度定量分析固有影响因素的噪声水平。试验分析表明,通过利用Simulink仿真系统可以获得固有因素产生的噪声水平,并提出抑制方案。针对搭载环境测量误差,还分析了实测飞行中姿态和质量的改变对重力梯度测量值造成的环境影响,提出了基于点质量源的自身梯度校正方法。