地球动力学过程中的波动现象及其在地震预报中的应用

讨论了地球内部的波动现象与构造及地震间的关系。引进了４类广义构造波。它们是：表现为地球不同年代的综合构造运动结果的超长周期构造波；由地震活动性迁移，即所谓地震活动波所反映的长周期（不同类型与不同速度的，周期从几年到几十年）构造波；由地震前兆三阶段发展过程反映出的中等周期（从几月到几年）构造波；以及由地下水位、地倾斜、重力、地震波、电磁辐射、地声等的变化所记录的短周期（从几分到几天）构造波。地震活动波又有３类，可分别用广义瑞利型构造波、广义洛夫型构造波及广义导波型构造波来解释。最后，研讨了地球内部波动现象在地震研究中的应用，包括它们在地震危险性分析与地震区划、地震预报以及地震成因研究中的应用。     

Composition of ciliate fauna and its seasonal changes in fluvial drift

Ciliate composition and its seasonal changes in seston depending on the discharge regime were analyzed in the lower rhithral area of the river Sava. Higher values for ciliate density, dry biomass, index of species diversity and concentration of particulate organic matter (POM) were associated with discharge peaks. Using the power model: y = ax^b ± c a significant positive correlation was found between POM and ciliate dry biomass (as dependent variables) and discharge (as independent variable). The ciliate drift constitutes 0.78% of the total annual POM transport. Depending on the discharge regime, the composition of ciliate drift reflects the temporal and structural changes in periphytic community.     

用重力压密原理评价大型滑坡滑面强度参数

大型滑坡泥质滑动面强度参数的正确选取，是作好稳定性评价的重要环节。本文从滑坡形成初期时滑带土的结构特征，滑面的应力状态出发，提出了用重力压密原理研究滑带土的物理力学性质，并用实例介绍了研究步骤和评价效果，为大型滑坡动面强度参数评价提出了新的途径。     

西北干旱区乡村性评价及驱动机制研究——以甘肃武威为例

基于武威市1949~2013年65 a的社会经济统计数据,以县域为基本单元构建乡村性指标体系,通过测算各县区乡村性指数和分异指数来分析乡村性的时间演变和空间分异,并从社会经济和技术经济两个维度探讨了乡村性演变的影响因素。结果表明：① 1949~2013年间武威市各县区乡村性指数总体呈减弱趋势,但减弱幅度和速度存在差异。② 各县区乡村性分异指数呈波动增长趋势,2000年以后乡村性分异指数急剧增长,表明各县区乡村性差异越来越大。③ 社会经济和技术经济是影响乡村性变动的两大动因,各因素的发展致使城乡差距缩小、乡村性水平减弱、城乡一体化发展趋势明显。     

Crystal structures of iron bearing tetrahedrite and tennantite at 25 and 250°C by means of Rietveld refinement of synchrotron data

Rietveld refinement of X-ray synchrotron data was performed for two synthetic tetrahedrite samples, with 0.61 and 1.83 Fe atoms, and two synthetic tennantite samples with 0.10 and 1.23 Fe atoms p.f.u. M₁₂(Sb,As)₄S₁₃. Measurements were performed at 25 and 250°C. For both the phases, increased Fe substitution is reflected in the increased tetrahedral ‘Cu1’–S distance (‘Cu1’ is a site of Fe substitution) and Cu2–S distances. Cu2 was refined as a split position; the Cu2–Cu2 split about the plane of the S1₂S2 triangle is about 0.56 and 0.65 Å for tetrahedrite and tennantite, respectively. Cu2–Cu2 distances in the structure cavity are 2.8–2.9 Å. Between 25 and 250°C, the lattice parameter a increased by 0.02–0.04 Å and the interatomic distances by 0.01 Å on an average. Thermal expansion coefficients of little-substituted samples are similar to those of unsubstituted samples, whereas thermal expansion appears to decrease with increasing substitution by Fe. The Cu2–Cu2 split increases at 250°C by about 0.1 Å for tetrahedrite and by more than 0.15 Å for tennantite but the cage expansion is minimal so that the Cu2–Cu2 distances in the cavity decrease with temperature. Difference Fourier maps indicate that there is little residual electron density left between the two Cu2 half-sites in tetrahedrite but this inter-site density is substantially higher in tennantite. It increases with temperature, especially in the little-substituted tennantite sample.     

Visualization of time-dependent dynamics of postglacial rebound

Postglacial rebound is a major geological process which plays an important role in many areas in the earth sciences. Up to now, most of the images derived from studies of the glacial isostatic adjustment phenomenon have been concerned with surface signatures, such as the uplift and gravity anomalies and not much attention has been paid on the dynamical responses in the mantle. We will make use of the 3D visualization package Amira to depict both the external and internal deformation histories of the transient viscoelastic flow inside the mantle induced by postglacial uplift. Of particularly great interest are the transient displacement fields and shear heating inside the mantle. This same visualization technology can be brought to bear in the future for visualizing tsunami waves in ocean basins excited by earthquakes, volcanic eruptions and InSAR images. We have also integrated the visualization results into the Google Earth virtual globe by combining this scheme with the Amira package to provide a better geographical and dynamical context. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

基于大数据的城市服务业空间关联分析

信息技术与电商平台的发展,产生了各种各样的大数据。在城市服务业中,商家在电商平台上注册自己带有坐标的信息,构成了空间服务业的空间大数据源。首先建立限定距离阈值的空间关联规则数据模型,介绍该模型产生频繁项集和关联规则的方法与步骤。最后利用Python爬取糯米网南宁站的商家信息,用Apriori算法做出了10~1 000 m 6种距离阈值的空间关联规则和服务业空间频繁项集。     

Using external tropospheric corrections to improve GNSS positioning of hot-air balloon

High accurate global navigation satellite systems (GNSS) require to correct a signal delay caused by the troposphere. The delay can be estimated along with other unknowns or introduced from external models. We assess the impact of the recently developed augmentation tropospheric model on real-time kinematic precise point positioning (PPP). The model is based on numerical weather forecast and thus reflects the actual state of weather conditions. Using the G-Nut/Geb software, we processed GNSS and meteorological data collected during the experiment using a hot-air balloon flying up to an altitude of 2000 m. We studied the impacts of random walk noise setting of zenith total delay (ZTD) on estimated parameters and the mutual correlations, the use of external tropospheric corrections, the use of data from a single or dual GNSS constellation and the use of Kalman filter and backward smoothing processing methods. We observed a significant negative correlation of the estimated rover height and ZTD which depends on constraining ZTD estimates. Such correlation caused a degraded performance of both parameters when estimated simultaneously, in particular for a single GNSS constellation. The impact of ZTD constraining reached up to 50-cm differences in the rover height. Introducing external tropospheric corrections improved the PPP solution regarding: (1) shortened convergence, (2) better overall robustness, particularly, in case of degraded satellite geometry, (3) less adjusted parameters with lower correlations. The numerical weather model-driven PPP resulted in 9–12- and 5–6-cm uncertainties in the rover altitude using the Kalman filter and the backward smoothing, respectively. Compared to standard PPP, it indicates better performance by a factor of 1–2 depending on the availability of GNSS constellations, the troposphere constraining and the processing strategy.     

Critical equipotential surfaces in close binary systems

The well-known problem of reckoning the critical surfaces (equipotential zero-velocity surfaces) in the close binary systems is approached by an independent method. The formulation of the problem is based on the assumptions of the binary's matter consisting of ionized hydrogen, the system possessing black-body radiation, a potential magnetic field, being in adiabatic equilibrium. Total pressure and total internal energy are examined. The model, implying synchronous rotation of the components, is described by hydromagnetic equations. For a statical case, however, it is representable by the equation of motion alone. Next, the temperature field is reproduced whereby the ratioP _r/P_g= is playing part of a free parameter. The resulting potential functions, applied to particular binaries, furnish the Lagrangian collinear points, critical surfaces and potentials over them in terms of . The families of surfaces thus obtained, compared with those springing from the Roche model, differ qualitatively in their geometry, position of the collinear equilibrium points, number of possible equilibrium states and the values of critical potentials. At identifying the allowed and forbidden regions of the gas motion new areas have been disclosed across which the gas outflow can take place and more possibilities of shell forming both around the individual components and the system as a whole. As the gas enthalpy and radiation are increased, the surfaces' geometry is undergoing changes. The method enables the intensity of gas velocity to be ascertained at any point in the system.The results of the method outlined here complement the picture of possible equilibrium states in the close binary systems in the presence of radiation and magnetic field.