由钻孔应力（应变）观测中的元件测值推断测区的附加主应力比值和方向

本文讨论了在钻孔应力(应变)相对观测中,互成45°夹角元件测值间的关系,以及利用其测值推断测区附加应力状态的方法。     

甘肃省玉米产量的主成分分析

应用自然正交函数方法将甘肃省玉米产量的趋势产量项(Yt)和气候产量项(Yw) 进行展开，展开后的Yt、Yw第一特征向量都表明了Yt、Yw总趋势的一致性，其大值中心表明产量变率较大。通过对各主成分主要时间系数与各站Yt、Yw进行相关分布分析，筛选出全省玉米产量的八个站点，这些站点基本上代表了本省不同类型的农业气候区域的玉米产量水平和生育状况。     

Patterns of stress corrosion: Geometry of the principal stresses

We investigate migration of fluids through the rock in the stress corrosion process. The fluids migrate along the trajectories of the principal stress field. We study geometry of these trajectories, including singularities, limit cycles, and possible bifurcations. We describe corresponding configurations of weakened zones in the lithosphere due to the fluid migration.     

Characteristic scales, temporal variability modes and simulation of monthly Elbe River flow time series at ungauged locations

Spatial and temporal patterns of the long-range extreme monthly Elbe River flows across Germany are investigated, using various statistical methods, among others, principal component and wavelet analysis. Characteristic time scales are derived for various time series statistics. The wavelet analysis of the raw river discharge data as well as of the major principal component reveal the main oscillatory components and their temporal behavior, namely low frequency oscillations at interannual (6.9 yr) and interdecadal (13.9 yr) scales. The EOFs at ungauged stations are estimated from the principal components of the observed time series sampled over a limited time span whose length equals the major temporal variability scale (≈7 yr). The EOFs (empirical orthogonal functions) obtained in this way are subsequently used to simulate long-range flows at these locations. A comparison of this method with linear interpolation and ordinary kriging of the EOF shows the superiority of the former in representing the distributional properties of the observed time series. The simulated time series preserve also short and long-memory.     

Use of magnetic signatures to correlate tephra layers in Holocene loessial soil profiles from a small region, SE Iceland

Rock magnetic measurements have been applied to two adjacent loessial soil sections from a small region, SE Iceland. The soils are composed of reworked locally derived sediment (including airfall tephra) and also contain several visible discrete airfall tephra layers. The main magnetic minerals in the airfall tephras are ferrimagnetic (e.g. magnetite) with paramagnetic minerals also present. The main magnetic grain sizes in the tephras are pseudo single domain. The results show that individual tephras do not have unique magnetic signatures that can be used for identification and correlation between sedimentary sequences. However, a correlation of tephra layers was achieved through the application of statistical techniques to a comprehensive dataset of magnetic parameters. Similarity coefficients and Euclidian distance measures were used to identify the best correlation between tephra layers in the two soil profiles. The technique works well providing some tephras present within both profiles have been formally identified (e.g. Oraefajokulla ad 1362) using electron microprobe analyses. Given this initial framework, the statistical analyses of the magnetic parameters can help in the identification and correlation of unknown tephras between two soil profiles.     

我国国土主体功能区划刍议

从主体功能区划的概念、工作思路、区划方法和实施机制4方面对我国国土主体功能区划工作进行了初步探讨,从而界定了主体功能区划的概念,对比了分摊法和汇总法,提出了校核法,讨论了划分的层次和空间单元大小、定性与定量的关系、指标的选取、域值的确定等划分方法问题,对主体功能区划的实施机制进行了初步探讨。     

Lithologic and structural mapping of the Abiete–Toko gold district in southern Cameroon,using Landsat 7 ETM+/SRTM

The geology of the Abiete–Toko gold district in South Cameroon is investigated using a combination of Landsat 7 ETM+/SRTM image processing techniques, conventional geologic field mapping and geostatistical analysis. The satellite images were treated using Principal Component Analysis and Sobel filters to separate the background noise from lithotectonic structures which were matched with field data. The results show that this area has been affected by a polyphase deformation represented by S₁ foliation, S_c1 schistosity, L₁ lineation, S₂ foliation, F₂ folds, and F₃ shear zones and faults. A detailed analysis of all the structures led to the identification of two major networks of dextral and sinistral shear zones oriented WNW–ESE and NE–SW, respectively. These results may serve in mining prospection, especially in the search for tectonically controlled primary mineralization and so may significantly guide the exploration of primary gold mineralization in the Abiete–Toko area subjected to years of artisanal gold mining.     

基于ARMA-BP集成的藻类叶绿素a预测研究

藻类叶绿素a浓度是反映太湖水体富营养化程度的重要参数指标。以太湖2010—2011年5—10月旬平均叶绿素a浓度和气象资料数据作为建模样本, 通过对气象资料进行主成分分析, 得到4种主要气象因子作为输入, 建立时间序列ARMA预测模型与BP神经网络预测模型, 并对2012年数据进行预测。利用两种模型在线性空间和非线性空间的预测优势, 将叶绿素a数据结构分解为线性自相关主体和非线性残差两部分。首先用ARMA模型预测序列的线性主体, 然后用BP模型对其非线性残差进行估计, 最终集成整个序列的预测结果, 建立了ARMA-BP预测模型。3种模型的预测效果为ARMA-BP＞BP＞ARMA。     

Principal component analysis and hierarchical cluster analyses of arsenic groundwater geochemistry in the Hetao basin,Inner Mongolia

Although high As groundwater has been observed in shallow groundwater of the Hetao basin, little is known about As distribution in deep groundwater. Quantitative investigations into relationships among chemical properties and among samples in different areas were carried out. Ninety groundwater samples were collected from deep aquifers of the northwest of the basin. Twenty-two physicochemical parameters were obtained for each sample. Statistical methods, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), were used to analyze those data. Results show that As species were highly correlated with Fe species, NH₄-N and pH. Furthermore, result of PCA indicates that high As groundwater was controlled by geological, reducing and oxic factors. The samples are classified into three clusters in HCA, which corresponded to the alluvial fans, the distal zone and the flat plain. Moreover, the combination of PCA with HCA shows the different dominant factors in different areas. In the alluvial fans, groundwater is influenced by oxic factors, and low As concentrations are observed. In the distal zone, groundwater is under suboxic conditions, which is dominated by reducing and geological factors. In the flat plain, groundwater is characterized by reducing conditions and high As concentrations, which is dominated by the reducing factor. This investigations indicate that deep groundwater in the alluvial fans mostly contains low As concentrations but high NO₃ and U concentrations, and needs to be carefully checked prior to being used for drinking water sources.     

Is the catch quota management (CQM) mechanism attractive to fishers? A preliminary analysis of the Danish 2011 CQM trial project

There is a demand for a management mechanism that can reduce the discarding problems of EU fisheries. Catch quota management (CQM) seems to be a promising candidate for such a mechanism. Drawing on a principal–agent model, the objective of this study is to develop and test a method for investigating if the CQM mechanism is efficient in providing fishers with incentives for participating in CQM and complying with the rules. The study uses the 2011 Danish CQM trial project as its empirical basis. The results indicate that CQM fishers have a higher average gross income compared to fishers harvesting according to the conventional rules. Hence, there is an incentive for fishers to participate in the trial. However, with the possibility to cheat, CQM fishers may achieve even higher gross income. It is not obvious that the CQM mechanism׳s payoff structure (incentives) is attractive enough to ensure that the fishers comply with the rules. The empirical data illustrate that without discarding the CQM fishers achieve a lower average price for their catches. Therefore, to make the CQM mechanism sufficiently attractive to fishers, the participating fishers must be compensated.