2005年10月8日巴基斯坦7.8级地震热红外异常

收集了2005年巴基斯坦7.8级地震区Noaa17/AVHRR的2004-2005年的热红外遥感资料,并进行地表温度反演,得到了以震中为中心7°×7°范围的地表温度值。经热红外图像解译与构造关系对比分析,表明热红外解译图像与构造分布具有一致性。震源区地表温度时间序列显示:震前大约3个月内震源区存在明显的热红外异常。     

Climate induced temperature effects on growth performance, fecundity and recruitment in marine fish: developing a hypothesis for cause and effect relationships in Atlantic cod (Gadus morhua) and common eelpout (Zoarces viviparus)

Effects of global warming on animal distribution and performance become visible in many marine ecosystems. The present study was designed to develop a concept for a cause and effect understanding with respect to temperature changes and to explain ecological findings based on physiological processes. The concept is based on a wide comparison of invertebrate and fish species with a special focus on recent data obtained in two model species of fish. These fish species are both characterized by northern and southern distribution limits in the North Atlantic: eelpout (Zoarces viviparus), as a typical non-migrating inhabitant of the coastal zone and the cod (Gadus morhua), as a typical inhabitant of the continental shelf with a high importance for fisheries.Mathematical modelling demonstrates a clear significant correlation between climate induced temperature fluctuations and the recruitment of cod stocks. Growth performance in cod is optimal at temperatures close to 10°C, regardless of the population investigated in a latitudinal cline. However, temperature specific growth rates decrease at higher latitudes. Also, fecundity is less in White Sea than in North and Baltic Sea cod or eelpout populations. These findings suggest that a cold-induced shift in energy budget occurs which is unfavorable for growth performance and fecundity. Thermal tolerance limits shift depending on latitude and are characterized by oxygen limitation at both low or high temperatures. Oxygen supply to tissues is optimized at low temperature by a shift in hemoglobin isoforms and oxygen binding properties to lower affinities and higher unloading potential. Protective stimulation of heat shock protein synthesis was not observed.According to a recent model of thermal tolerance the downward shift of tolerance limits during cold adaptation is associated with rising mitochondrial densities and, thus, aerobic capacity and performance in the cold, especially in eurythermal species. At the same time the costs of mitochondrial maintenance reflected by mitochondrial proton leakage should rise leaving a lower energy fraction for growth and reproduction. The preliminary conclusion can be drawn that warming will cause a northern shift of distribution limits for both species with a rise in growth performance and fecundity larger than expected from the Q₁₀ effect in the north and lower growth or even extinction of the species in the south. Such a shift may heavily affect fishing activities in the North Sea.     

圣安德烈斯断层门多西诺三联点迁移的构造热效应

由于圣安德烈斯断层门多西诺三联点向北迁移，或北美板块的相对向南运动，驱动角落流使地幔热物质向板片窗上涌，造成地幔温度升高和部分熔融．本文通过二维暂态有限单元法计算表明，当北美盖层厚度为20km时，计算预测的地热分布、部分熔融百分比、岩浆岩活动的时空分布特征等都与实际地热、地震和地质观测很好地吻合，确认了角落流机制和它引起的暂态热过程的重要性．     

大功率电波加热电离层中热自聚焦不稳定性的理论研究和数值模拟

本文首先从电子密度及电子温度的输运方程和考虑自作用时的电磁波波动方程出发, 利用简正模展开的方法推导出泵波在反射区域激发出热自聚焦不稳定性(thermal self-focusing instabilities, TSFI)所需电场阈值以及其增长率的完整数学表达式, 并估算了TSFI激发阈值及所对应的有效辐射功率(ERP)的量级.随后利用三维垂直加热的理论模型, 结合国际参考电离层(IRI-2012)和中性大气模型(MSIS-E-00)给出的背景参数, 数值模拟了大功率高频泵波加热电离层时泵波反射区域电子密度及电子温度因TSFI而产生的变化及发展的过程, 并对比分析了不同背景参数对较热效果的影响.结果表明:当高频泵波的加热阈值达到或超过百毫伏每米的量级时, 即可激发TSFI, 发展出大尺度电子密度及温度不均匀体, 这些不均匀体内的密度耗空约为4%~10%, 而电子温度剧烈增长, 到达背景温度值的1.6~2.1倍;且在相当的加热条件下, 背景电子温度越低、电子密度越小, 加热效果越显著;电子密度及电子温度的扰动幅度随着加热时间的推移而逐渐减小, 即扰动逐渐趋于饱和, 且电子温度要快于电子密度达到饱和状态.本文还对泵波反射高度处的电子密度及电子温度变化率进行采样并求得其功率谱密度, 分析结果表明:TSFI发展出的大尺度不均匀体满足幂律谱结构, 谱指数随着加热的进行逐渐趋于稳定, 白天与夜间的幂律谱指数区别不大, 但电子密度与电子温度的幂律谱有所区别.     

鄂尔多斯盆地深部热结构特征及其对华北克拉通破坏的启示

基于二维稳态热传导方程,利用有限元数值模拟方法,选取东西向横穿鄂尔多斯盆地地质与地球物理解释大剖面进行了深部温度场数值模拟研究,得到了华北克拉通西部的鄂尔多斯盆地下伏岩石圈热结构特征.地幔热流变化范围:21.2~24.5 mW·m-2,体现为东高西低特征.壳幔热流比(Qc/Qm)介于1.51~1.84之间,为"热壳冷幔".与华北东部地幔热流对比表明,西部的鄂尔多斯盆地相对处于稳定的深部动力学环境.在岩石圈热结构研究基础上,对克拉通地震岩石圈与热岩石圈厚度差异进行了对比,研究表明:鄂尔多斯盆地西部地震岩石圈与热岩石圈厚度差异约达140 km,而东部的汾渭地堑,渤海湾盆地二者差异逐渐减小.华北克拉通自西向东,地震岩石圈厚度与热岩石圈厚度差异不断减小,意味着华北克拉通岩石圈下部的软流圈地幔黏性系数自西向东逐渐降低,本文从地热学角度可能印证了太平洋俯冲脱水作用对华北克拉通的影响.     

Two-and three-dimensional linear convection in a rotating annulus

Abstract

An exceptional case to the model-independent theory of Knobloch (1995) is presented, by investigating a rotating cylindrical annulus of height H and side wall radii r _o and r _i, with non-slip, perfectly thermally conducting side walls and thermally insulating stress-free ends. Radial heating permits the possibility of either two- or three-dimensional convective solutions being the preferred mode. An analytical solution is obtained for the two-dimensional case and a numerical solution for the three-dimensional solution, which is also applied to the two-dimensional solution. It is shown that both two- and three-dimensional solutions can be realized depending on the aspect ratio, γ = H/d, where d = r _o-r _i is the thickness of the annulus, the radii ratio λ = r _i/r _o and the rotation rate of the model. For γ = O(1) and λ = 0.4, the preferred convective solution is three-dimensional when the Taylor number, T < 10² and two-dimensional for T > 10². For small aspect ratios, γ ? 1, the preferred mode is two-dimensional for all rotation rates.     

The electrical conductivity of Posidonia black shales — from magnetotelluric exploration to rock samples

We carried out a magnetotelluric field campaign in the South–East Lower Saxony Basin, Germany, with the main goal of testing this method for imaging regional Posidonia black shale sediments. Two‐dimensional inversion results of the magnetotelluric data show a series of conductive structures correlating with brine‐saturated sediments but also with deeper, anthracitic Westphalian/Namurian coals. None of these structures can be directly related with the Posidonia black shale, which appears to be generally resistive and therefore difficult to resolve with the magnetotelluric method. This assumption is supported by measurements of electrical resistivity on a set of Posidonia shale samples from the Hils syncline in the Lower Saxony basin. These rock samples were collected in shallow boreholes and show immature (0.53% Ro), oil (0.88% Ro), and gas (1.45% Ro) window thermal maturities. None of the black shale samples showed low electrical resistivity, particularly those with oil window maturity show resistivity exceeding 10⁴ Ωm. Moreover, we could not observe a direct correlation between maturity and electrical resistivity; the Harderode samples showed the highest resistivity, whereas the Haddessen samples showed the lowest. A similar trend has been seen for coals in different states of thermal maturation. Saturation of the samples with distilled and saline water solutions led to decreasing electrical resistivity. Moreover, a positive correlation of electrical resistivity with porosity is observed for the Wickensen and Harderode samples, which suggests that the electrical resistivity of the Posidonia black shale is mainly controlled by porosity.     

川东地区古生界主要泥页岩最高古温度特征

泥页岩的热演化过程与其经历的古温度史相关,最高古温度决定它的最终热演化程度.本文利用古温标方法恢复了川东地区古生界主要泥页岩层系经历的最高古温度.研究结果表明,它们在距今80-90 Ma时达到最高古温度,龙潭组顶面最高古温度150~220℃,龙潭组底面最高古温度160~230℃,龙马溪组顶面最高古温度160~250℃,五峰组底面最高古温度170~260℃,筇竹寺组顶面最高古温度210~320℃,筇竹寺组底面最高古温度210~320℃.各层最高古温度平面展布特征相似,最高温出现在涪陵-丰都一带,向南与向北温度均呈降低趋势,在达州-开江一带局部出现较高温.此外,结合川东地区古热流史分析认为,川东古生界泥页岩热演化过程具有阶段性,现今处于高-过成熟状态,达到最高古温度后生烃作用停止.川东地区经历较高的最高古温度随后快速抬升剥蚀有利于页岩气的成烃与成藏.     

Study of the Interaction Mechanism in the Biosorption of Copper(II) Ions onto Posidonia oceanica and Peat

A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption–desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4–6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q_max) at pH 6 of 85.78 and 49.69 mg g^?1, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO₃)₂, and EDTA was applied to copper‐saturated biosorbents. Around 65–70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH₂, and CH₃ in aliphatic structures, COO^? and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si? O groups on the surface of peat. The results of SEM‐EDX and FTIR analysis of copper‐saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption–desorption processes affected the thermal stability of the biosorbents.     

有机质对纳米级磁铁矿热稳定性的影响

单畴磁铁矿颗粒是地质样品中最重要的磁性载体,其稳定性一直备受关注.为了认识有机质对纳米级磁铁矿颗粒热稳定性的影响,本文对比研究了趋磁细菌AMB-1合成的单畴磁铁矿分别在全细胞中和经去胞提纯后的纯化磁小体中的热磁性质,以及热处理后样品的磁滞参数和低温磁性的变化.发现仅有磁小体膜包裹的纯化磁小体中单畴磁铁矿热稳定性极强,而全细胞中的单畴磁铁矿加热过程中发生了显著的热变化:磁铁矿在约270℃即开始转化,400℃以前几乎完全被有机质还原为顺磁性物质;同时在400℃以前,有机质的还原作用与有机质热分解引起磁小体链的坍塌,共同导致了样品矫顽力(Bc)、剩磁矫顽力(Bcr)和剩磁比(Mrs/Ms)的减小,以及矫顽力比(Bcr/Bc)的增加. 我们的实验结果清楚地表明,当地质样品中含有较多有机质组分并受热事件影响时,其中的单畴磁铁矿难以得到保存.