岩石层消减中的密度反转效应

根据模型实验的相似理论设计了实验模型和实验方法。实验结果表明,由消减板片密度反转引起的垂直牵引力,一部分用于驱动板片消减入地慢,一部分可转换为岩石层的水平牵引力;建立了板块水平运动速度、岩石层的消减速度以及海沟移动速度之间的关系;还阐述了不同的Benioff带具有不同的倾角和消减深度的的原因。这项实验工作为研究板块运动及其驱动机制问题提供参考。     

相位实时差分技术应用于飞行器交会对接研究

空间飞行器交会对接需要实时高精度地确定两飞行器的相对位置.应用GNSS引导两飞行器交会对接,是GNSS差分原理的一种特殊应用.星载接收机提供的载波相位观测值是高精度定位的基础,但是如何实时可靠地固定相位模糊度仍然是关键技术,提出了一种有效的模糊度实时解算算法,即在宽巷组合的基础上附加选权约束来固定两种不同波长的宽巷模糊度,然后依据组合法直接求解L1和L2相位模糊度整数解.实验结果显示,应用该算法进行模糊度单历元实时解算时,15km以内的短基线,解算成功率大于99%,能满足实时交会对接定位精度的要求.为了验证该算法在空间飞行器对接中的应用,采用仿真的方法模拟了两飞行器逼近和离开的过程,模拟并实时输出星载GNSS观测量.进而应用新算法实时估计两飞行器间相对位置,精度达到厘米级水平.我们的研究不但能进一步完善GNSS相位模糊度解算理论与方法,也可促进GNSS在航空飞行器编队飞行和交会对接等相关领域的应用.     

探地雷达波波动像的雅可比系数矩阵

波动成像最关切的一步就是求取成像方程的系数矩阵,也就是雅可比系数矩阵,也即波场对物性参数的偏导数矩阵。从探地雷达波满足的有限元波动方程出发,推导得到随时间可变的雅可比系数矩阵满足的波动方程,并阐述了在时间域和频率域分别求解该雅可比系数矩阵的方法。     

Zircon SHRIMP geochronology of the Xinkailing-Kele complex in the northwestern Lesser Xing''''an Range, and its geological implications

Located in the eastern portion of the Xing'an-Mongolian Orogenic Belt (XMOB), the Xinkailing-Kele complex has previously been considered to be Precambrian metamorphic rocks, mainly according to its relatively high metamorphic grade. Our filed observation, however, revealed that the complex is composed mainly of metamorphic rocks (Kele complex), tectono-schists ("Xinkailing Group"), and granitoids (Xinkailing granitic complex). Dating on these rocks using advanced SHRIMP zircon U-Pb technique indicates that: (1) Biotite-plagioclase gneiss from the Kele complex has a protolith age of 337±7 Ma (2σ) and a metamorphic age of 216±3 Ma (2σ); (2) the tectono-schist of the "Xinkailing Group" gave a magmatic age of 292±6 Ma (2σ), indicative of felsic volcanic protolith of the schist formed in late Paleozoic time; and (3) the Menluhedingzi and Lengchuan granites of the Xinkailing granitic complex were emplaced at 167±4 (2σ) and 164±4 Ma (2σ), respectively. These results suggest that the Xinkailing-Kele c     

松辽盆地南部乾安北地区扶余油层沉积微相分析

通过岩心观察和测井曲线分析确定岩石、岩相类型,结合测井相、骨架剖面微相及地震微相分析,对扶余油层4个砂层组的沉积微相展布及演化规律进行系统的研究.结果表明:扶余油层为曲流河、曲流河三角洲沉积体系,主要发育河床滞留沉积、点砂坝、河漫滩、水下分流河道与河口砂坝等沉积微相,其中曲流河道和水下分流河道砂体较发育,为物性较好的储...     

Hydrogen isotopic compositions and their environmental significance for individual n-alkanes in typical plants from land in China

Hydrogen isotopes of n-alkanes in grasses, tree leaves and reeds from six regions with latitudes of 20° to 39°N in China are measured by GC-TC-IRMS analytical technique in order to understand their hy- drogen isotopic compositions and environmental significance. The results show that a difference in δ D values (from -42.1‰ to -66.6‰) of n-alkanes exists among the same kinds of plants from various re- gions. Hydrogen isotopic compositions of most even carbon numbered n-alkanes in every plant are slightly hea...     

有色金属危急矿山的地球物理对策

针对我国已经出现的一批有色金属危急矿山的地质和地球物理特点,为查明地质构造、圈定有利成矿空间,寻找深部隐伏矿体和在勘探阶段测算矿体规模,形成了以电磁测深法、电化学法为主的一套地球物理方法体系。实践证明,该体系是有效的,并且它正在得到发展、充实和趋于完善。本文对这一方法体系作概要论述。     

The impacts of ‘05.6’ extreme flood event on riverine carbon fluxes in Xijiang River

An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River, the main trunk stream of the Zhujiang River. Samples were systematically collected during the flood event, and water quality parameters, including total suspended sediment (TSS), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) were analyzed, and riverine carbon concentrations associated with its changing pattern through the flood process were discussed. These parameters reflect the changes in basin surface flow and subsurface flow dur-ing the flood. This flood event influenced annual flux estimations of POC, DOC, and DIC to great extents. Based on carbon flux estimations for the year 2005 and the flood event (June 21-28) in the Xijiang River, it was found that DIC, DOC, and POC fluxes during ‘05.6’ flood event are 1.52×106 g.km?2.a?1, 0.24×106 g.km?2.a?1, and 0.54×106 g.km?2.a?1, and account for 14.87%, 24.75% and 44.89% of the annual fluxes in 2005, respectively. The results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components, be-ing important for accurate estimates of annual carbon fluxes in rivers with frequent floods.     

密执根盆地的热弹性模拟

沉积盆地的沉降过程受沉积物载荷的控制,但热也起着相当重要的作用。本文系用一种热弹性分层模型,考虑载荷及温度的共同影响,并计入了二者之间的弱耦合作用,讨论盆地的沉降过程。用这种热弹性分层模型模拟计算了密执根(Michigan)盆地在古生代的沉降曲线。密执根盆地是北美大陆上一近圆形的大盆地,具巨厚层沉积物,构造作用简单,属于稳定的克拉通内部盆地。计算结果与实际资料能较好地吻合,并且指出了有关热事件是升温或者降温的性质。     

可拓理论在地质工程领域应用中的改进

从可拓理论在工程地质领域应用出发,首先分析了工程地质领域问题的特点--"等级对关联度的影响效果相同.但等级的取值区间长度可以不同;等级内关联值随取值呈一阶线性变化";其次根据一个应用可拓理论中物元模型进行工程地质建模的简单特例,将物元模型展开,绘制出关于所有等级的"关联度一等级(影响因素值)"关系曲线,根据曲线与实际现象的不符之处分析模型存在的问题;提出一个新的关联函数计算方程,改进了原关联函数方程与实际的不符之处;最后通过分析改进后的方程曲线.论证改进后方程较符合工程地质领域问题的实际情况.总之,本文分析了可拓理论中的物元模型在工程地质领域中应用存在的问题,改进了物元模型中的关联度计算函数,对可拓模型在工程地质领域中的广泛和正确应用起到了推动作用.