应用Hydrolight模式研究含油水体辐射传输特性的关键技术

辐射传输模式Hydrolight在国际水色遥感研究领域已被广泛用于解决水体光学的各种问题,也是进行石油类污染水体辐射传输特性研究的有效模型。结合Hydrolight模式的机理、应用现状及含油水体的特点,提出了将该模式应用于光学特性复杂的石油污染水体辐射传输特性研究时需要解决的关键技术,包括测定石油污染水体吸收系数和散射系数、建立石油污染吸收和散射特性随波长和深度变化的参数化模型、确定油物质的吸附后悬浮颗粒物体散射函数模型等方面。依据2018年8月和2016年8月分别在辽宁大连港和辽宁盘锦辽河油田等区域测定的含油水体数据,讨论了这些关键技术的解决方案。     

海面溢油无人机高光谱遥感检测与厚度估算方法

海上溢油是海洋国家所面临的共同问题,但至今仍没有一种可靠实用的海上溢油准确识别和油量遥感监测方法。为此,本文以无人机高光谱遥感为手段,开展了海面溢油检测与厚度估算方法研究。实验中,通过搭建室外大型水槽溢油实验装置,获取了模拟真实海洋环境条件下不同溢油量的遥感和现场光谱数据,在此基础上,分析并提取了海上溢油特征光谱波段,给出了海上溢油高光谱检测模型;针对现场实验条件下水面油膜厚度难以测定的问题,设计了3种利用总体溢油量的油膜厚度估算模型。得到如下主要结论:（1）675 nm和699 nm是海上溢油检测的有效特征波段,但对极薄的油膜没有检测能力;（2）提出了归一化溢油指数模型、反比例模型和吸收基线模型等3种海上溢油油膜厚度估算模型,其中对于薄油膜（厚度≤ 5 μm）和厚油膜（厚度>50 μm）,反比例模型是溢油厚度反演的首选也是唯一选择。对于中厚度油膜,晴朗天气条件下,归一化溢油指数模型是油膜厚度反演的首选,同时反比例模型和溢油吸收基线模型也都有较好的反演能力,而在多云天气条件下,反比例模型效果最佳。     

广西田阳县那赖旧石器遗址发现的石制品和玻璃陨石

对广西田阳县那赖旧石器遗址进行实地调查,在百色盆地右江第Ⅳ级阶地的网纹红土中发现了一件玻璃陨石和大量的旧石器（包括12件手斧）。玻璃陨石的特征表明其为原地埋藏,未经后期流水作用搬运。玻璃陨石和石器之间的关系进一步证实,百色盆地第Ⅳ级阶地中保存的玻璃陨石可以代表手斧的埋藏年代。那赖遗址的石制品组合与百色盆地其他遗址的类似。通过与世界上其他阿舍利手斧在形态上和技艺上对比表明,该遗址手斧代表了早中更新世之交东亚的阿舍利技术特点。

     

Organic fraction of the total carbon burial flux deduced from carbon isotopes across the Permo-Triassic boundary at Meishan,Zhejiang Province,China

By combining the carbon cycle model with the records of carbonate and organic (kerogen) carbon isotope, this paper presents the calculation of the fraction of organic carbon burial (f _org) of beds 23–40 at the global boundary stratotype section and point (GSSP) of the Permian-Triassic boundary at Meishan, Zhejiang Province. The resulting calculation produces two episodes of f _org maxima observed to occur at beds 23–24 and 27–29, which respectively corresponds to the two episodic anoxic events indicated by the flourish of green sulfur bacteria. Two episodic f _org minima occurred at beds 25–26 and 32–34, generally coincident with the flourish of cyanobacteria (bed 26 and upper part of beds 29 to 34) as shown by the high value of 2-melthyhopnoanes. It appears that the f _org is related to the redox conditions, with greater f _org values observed under the reductive condition. The relationship between f _org and the total organic carbon (TOC) content was complex. The f _org value was low at some beds with a high TOC content (such as bed 26), while high observed at some beds with a low TOC content (e.g. bed 27). This association infers the important contribution of primary productivity to the TOC content. The original organic burial could be thus calculated through the configuration of the function of the primary productivity and f _org, which can be used to correct the residual TOC measured today. This investigation indicates that compiling the organic-inorganic carbon isotopes with the carbon cycle model favors to understand the fraction of organic carbon burial, providing information for the reconstruction of the coupling among biota, environments and organic burial. Journal of China University of Geosciences, 2007, 32(6): 767–773 [译自: 地球科学—中国地质大学学报]     

Prediction of thermal conductivity in reservoir rocks using fabric theory

An accurate prediction of the thermal conductivity of reservoir rocks in the subsurface is extremely important for a quantitative analysis of basin thermal history and hydrocarbon maturation. A model for calculating the thermal conductivity of reservoir rocks as a function of mineral composition, porosity, fluid type, and temperature has been developed based on fabric theory and experimental data. The study indicates that thermal conductivities of reservoir rocks are dependent on the volume fraction of components (minerals, porosity, and fluids), the temperature, and the fraction of series elements (FSE) which represents the way that the mineral components aggregate. The sensitivity test of the fabric model shows that quartz is the most sensitive mineral for the thermal conductivity of clastic rocks. The study results indicate that the FSE value is very critical. Different lithologies have different optimum FSE values because of different textures and sedimentary structures. The optimum FSE values are defined as those which result in the least error in the model computation of the thermal conductivity of the rocks. These values are 0.444 for water-saturated clay rocks, 0.498 for water-saturated sandstones, and 0.337 for water-saturated carbonates. Compared with the geometric mean model, the fabric model yields better results for the thermal conductivity, largely because the model parameters can be adjusted to satisfy different lithologies and to minimize the mean errors. The fabric model provides a good approach for estimating paleothermal conductivity in complex rock systems based on the mineral composition and pore fluid saturation of the rocks.     

新疆塔城地区地震地质特征

托里活断层、达尔布特活断层、独山子—安集海活断层及霍尔果斯—卡子湾活断层是塔城地区主要的全新世活断层，均有过多次古地震活动。自１９７７年以来，４级以上地震活动的空区在裕民县西北。据活断层古地震活动复现期及地震活动围空特点分析，今后１０年北天山或塔城西北可能有发生６级左右地震的危险。     

1954年甘肃山丹7(1/4)级地震史料补遗

在归纳1954年山丹71/4级地震已有地震史料的基础上,根据新获得的朱允明(2006)《山丹地震考察笔记》的详细考察资料,按照《新中国地震烈度表》重新评定了本次地震中各考察点的地震烈度,重新绘制了该地震的等震线图。其中,极震区Ⅸ—Ⅹ度区长轴方向为北西向,呈扁椭圆形,长轴直径约40km;Ⅷ度区南西侧为山丹盆地,第四纪沉积较厚,地震烈度衰减缓慢,因此,Ⅷ度区等震线向南明显突出。1954年山丹71/4级地震极震区位于龙首山北缘断裂西段,大致与该断裂的包代河-黑头山段相吻合,综合分析认为,该段断裂是本次地震的主发震断层,而破喇嘛顶西缘断裂和毛湖洞断裂是重要的参与断裂。     

Turbulence fields in the lee of two‐dimensional transverse dunes simulated in a wind tunnel

The turbulence field of airflow in the lee of a dune has significant impacts on dune dynamics and related processes. We used particle image velocimetry in a wind tunnel simulation to obtain detailed velocity measurements in the lee of two‐dimensional transverse dune models, then used the results to analyse their turbulence fields. The dune models used in this study had a single lee angle of 30°, and a total of six stoss angles: 3°, 5°, 10°, 15°, 20° and 25°. We used vorticity, turbulence intensity, Reynolds stress and turbulent kinetic energy to characterize the turbulence fields. These parameters were functions of stoss angle, wind velocity, distance from the dune crest and height above the ground surface. The stoss angles could generally be divided into two groups based on the profiles of mean velocity, turbulence and Reynolds stress. Stoss angles of 3° and 5° usually had similar profiles, and angles of 15°, 20° and 25° formed a second group with similar profiles. The profiles for the stoss angle of 10° were usually transitional and were intermediate between the two groups. Vorticity, Reynolds stress and turbulent kinetic energy increased monotonically with increasing free‐stream wind velocity, but their variations with respect to the stoss angle were complex. The stoss angles of 15° and 20° had the maximum values of these three parameters, thus these angles may have special significance in dune development given the characteristics of the mean velocity fields and turbulence fields they produce within the lee airflow. It is the streamwise velocity component and its turbulence that determine the surface shear stress. Copyright © 2008 John Wiley and Sons, Ltd.     

Introduction of structural aseismic research in China in recent four years

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…