The dependence of response spectrum on the tectonic ambient shear stress field

Introduction The acceleration response spectrum and peak ground acceleration are the necessary and im-portant parameters in earthquake-resistant design at present. They are still active research field. With the increase of digital high accurate strong motion observation data, especially the earth-quakes of Loma Prieta (M=7.0) in 1989; Landers (M=7.3) in 1992; Big Bear (M=6.4) in 1994 and Northridge (M=6.7) in 1994 in USA; Kozani (M=6.6) earthquake and afteshocks in 1995 in Greece; Dinar…     

北黄海盆地构造几何学研究新进展

北黄海盆地是发育于隆起背景之上的中、新生代沉积盆地。新一轮资源调查研究表明，北黄海中、新生代沉积盆地的基底由古生界沉积岩层和前寒武纪变质岩系等组成，盆地不同程度地发育下构造层（J3-K1）、中构造层（E2-E3）和上构造层（N）；从油气资源和中、新生代地层发育情况出发，将北黄海海域划分为辽东-海洋岛隆起区、北黄海盆地和胶北．刘公岛隆起区等3个一级构造单元，其中北黄海盆地包括6个二级构造单元和24个三级构造单元；盆地褶皱、断裂构造十分发育，褶皱构造可划分为区域挤压型、局部伴生型和披盖型等三类，断裂构造主要可见近EW—NE向、NW向和NNE向三组，其中近EW—NE向和NNE向断裂比较发育，控制着盆地隆、坳分布格局和沉积特征。     

An explanation for 13 consecutive day activities of Mrk 421

It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands.A geometric interpretation and standard shock or stochastic acceleration models of blazar emission have difficulty reproducing these observed behaviors.The present paper introduces a linear acceleration by integrating the reconnection electric field into the particle transport model for the observed behaviors of Mrk 421.We note that strong evidence for evolution in characteristic of multi-wavelength spectral energy distribution including shifting the peak frequency,accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands provides an important electrostatic acceleration diagnostic in a blazar jet.Assuming suitable model parameters,we apply the results of the simulation to the 13-day flaring event in March 2010 of Mrk 421,concentrating on the evolution of multiwavelength spectral energy distribution characteristic by shifting the peak frequency.It is clear that the ratio of the electric field and magnetic field strength plays an important role in temporal evolution of the peak frequency of synchrotron spectral energy distribution component.We suggest it is reasonable that the electrostatic acceleration is responsible for the evolution of multi-wavelength spectral energy distribution characteristic by shifting the peak frequency.Based on the model results,we assert that the peak frequency of the synchrotron spectral energy distribution component may signify a temporary characteristic of blazars,rather than a permanent one.     

地壳的拆离作用与华北克拉通破坏:晚中生代伸展构造约束

伸展条件下的地壳拆离作用是岩石圈减薄的重要浅部构造响应。晚中生代时期的伸展构造(包括拆离断层、变质核杂岩构造和断陷盆地)在华北、华南、东北和东蒙古及贝加尔地区普遍发育,它们切过上部地壳(断陷盆地)、中、上地壳(拆离断层)或中部地壳(变质核杂岩)。地壳拆离作用具有运动学极性(NWW或SEE)、几何学宏观(区域)对称与微观(局部)不对称性、遍布全区但不均匀性,以及形成时间的跨越性(140~60Ma)等特点,并使得地壳和岩石圈发生显著的减薄。本文研究揭示出现今岩石圈厚度变化与晚中生代伸展构造的发育程度和分布之间并没有必然的联系。其变化的基本规律是,除新生代裂陷发育区岩石圈厚度明显较小且厚度有迅速变化外,从华北向贝加尔地区总体的变化趋势是逐渐加厚,也即东亚地区岩石圈具有楔形形态。晚中生代时期的地壳(或地幔)拆离作用伴随着广泛的岩石圈减薄作用,区域岩石圈同时遭受到一定程度的减薄和破坏,华北克拉通在这一时期的破坏仅仅是区域岩石圈减薄在华北的具体体现。     

附有标高刻度的三维立体剖面图的模型方法及其在垂直形变分析中的应用

提出了一种用于垂直形变分析的附有标高刻度的三维立体剖面图的全新模型方法 ,介绍了用这一模型方法建立国家复测水准网三维立体剖面图模型的过程。使用表明 ,这一模型方法与目前常用的三维空间表示方法相比 ,在定量、定位分析水准点的沉降变化时具有直观、快速等优点。     

Variational Bayesian independent component analysis for spectral unmixing in remote sensing image

Spectral unmixing is a key technology of optical remote sensing image analysis; it not only influences the accuracy of the extraction of land cover information and automatic classification of topographical objects, but also greatly hinders the development of quantitative remote sensing. Independent component analysis (ICA) is a statistical method which is recently developed to extract the independent linear components, and which can realize the extraction of endmembers as well as fractional abundances with little a priori knowledge. However, ICA still cannot process the correlations among the various components. To overcome this problem, variational Bayesian independent component analysis (VBICA) has been proposed to process optical remote sensing images. In the Bayesian framework, the separation of independent components of remote sensing image has finally been achieved with conditional independence standards of Bayesian network and approximate variational algorithm. In the simulative image and real AVIRIS hyperspectral remote sensing image, the VBICA algorithm demonstrates its better performance. The experiment’s results indicate that the proposed VBICA algorithm is feasible, which has obvious advantages and a good application prospect. The reason is that it can effectively overcome the correlations between the various components in remote sensing images and break through the limitations of traditional remote sensing images analysis. Last but not least, the VBICA algorithm is applied in the classification of the TM multispectral remote sensing images. Compared to basic maximum likelihood classification, principal component analysis and FastICA algorithms, VBICA improves the classification accuracy of remote sensing images, and contributes to the further extension of the application of ICA in remote sensing image analysis.     

SPI-based evaluation of drought events in Xinjiang, China

Daily precipitation data for 1957?C2009 from 53 stations in the Xinjiang, China, are analyzed, based on the Standardized Precipitation Index (SPI) with the aim to investigate spatio-temporal patterns of droughts. The Mann?CKendall trend test is used to detect the trends in the SPI values of monthly drought series, drought severity and drought duration. The frequencies of moderate, severe and extreme droughts are higher in the North Xinjiang, while mild droughts occur more often in the South Xinjiang. A decreasing frequency of droughts in the North Xinjiang is found in winter, but a drying tendency is detected in the western parts of the North Xinjiang during spring, summer and autumn, which may be harmful for agriculture. The South Xinjiang seems to be getting wetter in summer, while the south parts of the South Xinjiang seem to be getting drier in spring. The middle of the East Xinjiang is identified to be in a slightly dry tendency. The drought severity is decreasing and drought duration is getting shorter in the North Xinjiang, while both of them increase in the southern parts of the South Xinjiang. In addition, droughts in the middle parts of the East Xinjiang are intensifying.     

基于专家经验值的滑坡易发性评价——以四川平武高坪铺库区为例

滑坡灾害的易发性评价方法和模型有很多,不同的学者又对其进行了不同的改进,形成了不同的方法。究竟哪种方法更好,还需要结合实际进行方法的比较分析。论文应用基于专家经验值的二元统计法分析了四川平武高坪铺库区(约32 km2)高程、岩性、与居民点距离、与河流距离、坡度和坡向6种因素对滑坡灾害影响,并在此基础上进行了滑坡易发性评价。     

从地温场特征探讨兰州断陷盆地地热资源前景

根据祁连造山带东段地温梯度、大地热流场、温泉和地热异常孔空间分布 ,以华家岭—武山近SN向隐伏深断裂为界 ,东边地温场高、温泉多 ,为隆起断裂型中低温地热田 ,其西地温场低于东部 ,地热异常孔为沉降盆地型地热异常指示 ,可为地热田开发提供信息特征。并对兰州断陷盆地的地热资源前景和开发前期工程进行探讨。     

宽级配砂土基料-滤层系统的室内模型试验研究

基料一滤层利用数码可视化跟踪技术、计算机信息实时处理技术和土体变形无标点量测技术,对宽级配基料一滤层系统进行了渗透室内模型试验。探讨了滤层准则的适用性,研究了不同滤层厚度和加压速率对管涌发生发展的影响。结果表明：传统太沙基滤层准则不适用于宽级配砂土,建议采用可移动颗粒中的d85s进行滤层准则设计;增加滤层厚度可提高系统的抗渗透破坏能力,但提高滤层厚度对提高整个系统抵抗渗透能力作用不大;水力梯度增加较快不利于系统的稳定。