腾格里沙漠南缘末次间冰期5e亚段的微量元素特征及其反映的古气候

腾格里沙漠南缘土门剖面TMS5e层段由16层风成砂、11层湖积黄土和5层湖相沉积构成,其年代相当于深海氧同位素5e。分析结果表明,TMS5e的10种微量元素的含量依次为PMnSrRbVCrZnNiCuNb。就平均值来看,古流动沙丘砂的各微量元素含量最低,其次为古半固定-固定沙丘砂,但两者的各微量元素含量都明显低于整个TMS5e层段相应平均值;黄土状亚砂土微量元素含量稍低于整个TMS5e层段相应平均值;湖相沉积和湖积黄土的各微量元素含量相差较小,且明显都高于整个TMS5e层段、古流动沙丘砂和黄土状亚砂土的平均值。土门剖面TMS5e层段的微量元素指示的MIS5e腾格里沙漠南缘的气候是不稳定的,经历了14.5次暖湿与冷干交替的气候波动,且可划分为TMS5e5(139~129.30ka BP)、TMS5e4(129.30~124ka BP)、TMS5e3(124~119.50ka BP)、TMS5e2(119.5~116.5ka BP)和TMS5e1(116.5~113.70ka BP)等5个亚段,分别可与格陵兰GRIP冰芯氧同位素所反映的MIS5e5、MIS5e4、MIS5e3、MIS5e2、MIS5e1等气候波动在性质和相位上相对应。     

Experimental study on grain size and soluble salt of saline soil in western Jilin Province, China

Western Jilin Province is a typical seasonal frost region, and is also one of the severest salinization areas of China. In this study, we aim to examine the saline soil in Da'an and Wukesong areas, western Jilin Province, and mainly analyze the granulometric composition and distribution of salt in soil profiles. Four sampling sites, two in Da'an and two in Wukesong respectively, are chosen for study. The granulometric composition, especially silt and clay content change in different sites and soil depths are analyzed. Analysis of total and components of soluble salt shows that the surface soil is weak carbonate saline, in which the main cation is Na⁺ and the main anion is HCO₃^-. The total amount of soluble salt presents a decreasing tendency with increasing depth. The comprehensive analysis of granulometric composition and soluble salt shows that the clay content and soluble salt content present similar variation tendency with an increase of depth.     

Preface to the special issue on seismic array analysis and CEArray

A seismic array is a set of seismographs being arranged in a regular geometric pattern to improve signalto-noise ratio (SNR).Seismic arrays at various length scales have been introduced since early 1960s and have been proved to be superior to single three-component stations for detecting and characterizing signals from earthquakes and explosions.     

Application of entropy analysis of in situ droplet-size spectra in evaluation of oil chemical dispersion efficacy

In situ droplet-size distributions were measured using a laser in situ scattering and transmissiometry (LISST-100X) particle size analyzer during the evaluation of natural and chemical dispersion efficiency of crude oils under different wave and current conditions. An entropy grouping of the in situ dispersed oil droplet-size spectra has classified the multi-modal droplet-size distributions into different groups based on similar droplet-size spectra characteristics within groups and distinction between groups. A generalized linear logistic regression model was fitted to analyze the effects of a number of factors and their interactions on the grouping of oil droplet-size spectra. The grouped results corresponded to the oil dispersion efficiency at different levels. This new method for droplet-size distribution data analysis can have significant implication in field evaluation of natural and chemical dispersion efficiency of oil.     

雅丹地貌研究评述与展望

雅丹地貌是风蚀地貌研究的重要对象,目前研究较为薄弱.雅丹地貌自瑞典探险家斯文赫定命名并开始研究以来,已有百余年的历史.随着科学技术的不断进步和研究方法的更新,已取得了重要进展,但仍存在许多问题.首先对雅丹地貌的科学定义、空间分布、形态特征、形成发育条件、形成发育过程、形成年代、与环境的关系和分类等8方面的进展和问题进行...     

鱼洞河滑坡地质特征及稳定性分析

在分析滑坡体工程地质条件和滑带土特征的基础上,分析影响因子对滑坡稳定性的敏感性.采用不平衡推力法和简布法,模拟多种外部条件,分析滑坡稳定性表明,滑坡整体处于稳定状态,局部可能失稳,对大坝安全运行不造成巨大危害.     

墙角型陡坡带岩性圈闭油气成藏条件研究——以渤海湾盆地石南陡坡带中段BZ3区古近系东营组为例

BZ3区西部陡坡带位于渤海湾盆地渤中凹陷石南陡坡带中段,构造上处于石臼坨凸起与凸起倾没端相交的夹角地带,石南一号断裂和石南二号断裂在此处相交,形成由多个复杂断阶所组成的复式墙角型陡坡坡折带.通过高精度层序地层学研究认为,BZ3区东营组东二下亚段发育3个4～5级基准面旋回,每个基准面旋回的上升半旋回的下部和下降半旋回均控...     

Characteristics of wind-blown sand and dynamic environment in the section of Wudaoliang-Tuotuo River along the Qinghai-Tibet Railway

Based on the detailed wind data and in situ observation of wind-blown sand in the section of Wudaoliang-Tuotuo River along the Qinghai-Tibet Railway, the dynamic environment of sand flow, involving sand-laden wind, drift potential, sand transport and their time variation were investigated. The prevailing direction of sand-laden wind obviously varies seasonally. Sand-laden wind presents unidirectional characteristics from winter to the next spring and its prevailing direction is westerly. In summer, northeasterly wind begins to increase and lasts for a short period. The annual drift potential along the Qinghai-Tibet Railway reaches 970.54 Vector Units (VU), which belongs to a high-energy wind environment. Directional variability of wind regime (RDP/DP, RDP is the resultant drift potential (RDP) and DP is drift potential) is 0.88. The RDP is 854.31VU in the direction of 89.7°, which indicates that westerly sand-laden wind prevails in this region. Sand transport is well correlated to the frequency of sand-laden wind and increases with drift potential logarithmically.     

Analytic solution of long wave propagation over a submerged hump

A new analytical solution of the long wave refraction by a submerged circular hump is presented. The geometry of the hump is assumed to be axisymmetric and be described by a power function in the radial direction with arbitrary values of both the exponent and the scaling factor. The submergence of the hump is also variable. The water surface elevation governed by the long wave version of the mild slope wave equation is solved by separation of variables, and a series solution of the Frobenius type is obtained. The solution is shown to be valid when the hump is sufficiently submerged or is of a relatively small height. Matching method is employed to illustrate the refraction of long waves under given conditions of incidence. Effects of the shape, the scale, and the submergence of the hump on wave refraction are discussed.     

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