青藏高原羌D2井海相烃源岩评价和油源对比

南羌塘坳陷D2井中侏罗统曲布组海相碳酸盐岩大部分为差—好烃源岩级别,少部分为非烃源岩级别,有机质母质类型以Ⅱ型为主,热演化处于成熟—高成熟阶段。油源对比分析表明,羌D2井曲布组白云岩和含沥青角砾岩中油质沥青来自该组地层灰岩烃源岩,具自生自储性质。同时,中侏罗统雀莫错组灰黑色泥页岩作为烃源层也存在提供油源的可能性。     

Zircon U–Pb ages and O–Nd isotopic composition of basement rocks in the North Qinling Terrain, central China: evidence for provenance and evolution

The Qinling Group was previously interpreted as the oldest Precambrian basement unit of the North Qinling Terrain, recording its formation and early crustal evolution. The Qinling Group consists predominantly of gneisses, amphibolites, and marbles, which underwent multi-phase deformation and metamorphism. In order to better constrain the provenance and tectonic setting of this group and the evolution of the North Qinling orogenic belt, in situ U–Pb dating and oxygen isotopic analysis of zircons in combination with whole-rock geochemistry and Sr–Nd isotope analysis was performed on the two dominant rock types, amphibolite and felsic gneiss. Felsic gneisses exhibit enrichment of LREEs and LILEs (Rb, Ba, Th, K, Pb), negative Eu anomalies and depletion of HFSEs (Nb, Ta, P, Ti). The rocks have slightly elevated δ¹⁸O values (6.5–9.3 ‰) and initial ε _Nd values of ?4.6 corresponding to two-stage Nd model age of 1.99 Ga. Amphibolites are also enriched in LILEs and LREEs and depleted in Nb and Ta and have homogeneous δ¹⁸O values (5.0–6.0 ‰), but higher initial ε _Nd values (2.8–3.3) and younger two-stage Nd model ages (1.29–1.24 Ga) compared to the gneisses. The zircon age record indicates that the gneisses and amphibolites were formed in a ~960 Ma volcanic arc environment rather than in a rift setting as previously suggested. A major metamorphic event took place during the Early Paleozoic. Based on the age spectrum of detrital zircons, the Qinling Group is interpreted as an autonomous geological unit, which was mainly derived mostly from 1,000 to 900 Ma old granitoid rocks. The North Qinling Terrain can be regarded as a remnant of the Grenville orogenic belt with an early Neoproterozoic evolution different from that of the North and South China blocks.     

Earthquake magnitude estimation using the τc and Pd method for earthquake early warning systems

Earthquake early warning （EEW） systems are one of the most effective ways to reduce earthquake disaster. Earthquake magnitude estimation is one of the most important and also the most difficult parts of the entire EEW system. In this paper, based on 142 earthquake events and 253 seismic records that were recorded by the KiK-net in Japan, and aftershocks of the large Wenchuan earthquake in Sichuan, we obtained earthquake magnitude estimation relationships using the τe and Pa methods. The standard variances of magnitude calculation of these two formulas are ±0.65 and ±0.56, respectively. The Pd value can also be used to estimate the peak ground motion of velocity, then warning information can be released to the public rapidly, according to the estimation results. In order to insure the stability and reliability of magnitude estimation results, we propose a compatibility test according to the natures of these two parameters. The reliability of the early warning information is significantly improved though this test.     

底栖生物生产力现场测试系统(BCSPM)的建立及其初步实验结果

为对生态系统的健康评估及底栖生物资源的开发利用提供技术支撑,在胶州湾筏式养殖水域,建立了底栖生物生产力现场测试系统(BCSPM),并在光照和黑暗条件下测定了沉积物海水界面溶解氧随时间的变化、计算了氧通量、估算了底栖总初级生产力和群落呼吸。在光照较强的中午时刻测定的群落总生产力为20．76mgCm^-2h^-1;养殖水域沉积物中的群落呼吸要高于邻近水域。BCSPM整体运转良好,初步结果为系统的改进和进一步实验提供了依据。     

Using chlorofluorocarbons (CFCs) and tritium (3H) to estimate groundwater age and flow velocity in Hohhot Basin,China

The concentrations of chlorofluorocarbons (CFC‐11, CFC‐12 and CFC‐113) and tritium (³H) content in groundwater were used to date groundwater age, delineate groundwater flow systems and estimate flow velocity in the Hohhot basin. The estimated young groundwater age is fallen in the bracket of 21 ~ 50 a and indicates the presence of two different age profiles and flow systems in the shallow groundwater system. Older age waters occur under the topographically low areas, where the aquifer is double‐layer aquifer system consisting of shallow unconfined‐semi‐confined aquifer and deep confined aquifer. This reflects long flow paths associated with regional flow. Groundwater (range from 21 to 34 years) in the north piedmont and east hilly areas, where the aquifer is a single‐layer aquifer consisting of alluvial fans, are typically younger than those in the low areas. The combination of CFCs dating with hydrogeological information indicates that both local and regional flow systems are present at the basin. The regional groundwater flow mainly flows from the north and east to the southwest, the local groundwater flow system occurs nearby the Hohhot city. The mean regional groundwater flow velocity of the shallow groundwater is estimated about 0.73 km/a. These findings can aid in refining hydrogeological conceptual model of the study area. Copyright © 2012 John Wiley & Sons, Ltd.     

A quantitative assessment on groundwater salinization in the Tarim River lower reaches, Northwest China

Based on monitored data from 840 samples, we assessed the spatial and temporal variability of groundwater salinization in the Tarim River lower reaches combining classical statistics and geostatistics. Results show that total dissolved solids （TDS） is significantly correlated with other related ions, such as Na＋, Mg2＋, Ca2-, C1- and K＋. TDS and underground water level have characteristics of spatial autocorrelation, both of which present the isotropic characteristic and con- form to the spherical model in each year from 2001-2009. TDS is basically greater than 1 g/L but less than 2 g/L in the Tarim River lower reaches, which indicates that salt stagnation pollution is more serious. The most serious salinization （3 g/L 〈 TDS _〈 35 g/L） contaminated area is mainly in the middle and lower part of the study area.     

需求驱动兵团空间数据本体语义的描述

针对兵团空间信息集成与共享异构数据语义的广泛性和复杂性,本文依据其领域特性和共享需求,采用本体作为兵团空间数据表示的方法,从应用领域出发,以需求来驱动兵团空间数据本体框架构建,提出了兵团空间数据的本体工程构建方法,研究了本体领域、概念类型、语义关系,并对空间数据本体进行了语义描述。评估表明该方法构建的兵团空间数据本体有效,有利于数据共享与互操作。     

Seismic prediction method of multiscale fractured reservoir

Common prestack fracture prediction methods cannot clearly distinguish multiplescale fractures. In this study, we propose a prediction method for macro- and mesoscale fractures based on fracture density distribution in reservoirs. First, we detect the macroscale fractures (larger than 1/4 wavelength) using the multidirectional coherence technique that is based on the curvelet transform and the mesoscale fractures (1/4–1/100 wavelength) using the seismic azimuthal anisotropy technique and prestack attenuation attributes, e.g., frequency attenuation gradient. Then, we combine the obtained fracture density distributions into a map and evaluate the variably scaled fractures. Application of the method to a seismic physical model of a fractured reservoir shows that the method overcomes the problem of discontinuous fracture density distribution generated by the prestack seismic azimuthal anisotropy method, distinguishes the fracture scales, and identifies the fractured zones accurately.     

Dynamic characteristics of shear buildings on laminated rubber bearings

Analytical solutions are derived for the dynamic characteristics of base-isolated shear buildings supported on laminated rubber bearings. The solution process takes into account the combined effects of the superstructure flexibility and the base raft inertia on the dynamic characteristics. A series of parametric studies is carried out and the effects of varying the stiffness and mass of the base-isolation system on the frequencies and mode shapes are identified. Approximate solutions for the fundamental base-isolated frequency and mode shape are obtained, which are suitable for use in the preliminary design of non-rigid base-isolated buildings.     

非规则性超高层建筑垂直度测量方法研究

超高层建筑垂直度测量成果是质量验收及偏差处理的重要参考依据,而超高层建筑的动态特性和非规则性在一定程度上增加了垂直度测量的难度。文中提出一种非规则性超高层建筑垂直度测量方法:采用智能全站仪监测系统进行超高层建筑周日摆动监测,利用GPS方法从宏观上分析测量基准的可靠性和准确性,采用静力矩方法计算垂直度偏差。应用实践表明,这种方法有效解决了施工控制网竖向传递倾斜偏差改正这一关键性技术难题,保障测量基准的准确性和可靠性,垂直度偏差的计算与表达是科学合理的,具有借鉴意义。