Analyzing the Relation Between Earthquakes and Active Faults Based on the Parameter Optimization Model

The gestation and occurrence of strong earthquakes are closely related to fault activity, which is not only revealed by abundant experimentation and seismism but also proved by modern seismology. On the Chinese mainland, the relation between earthquake activity and active faults is one of the bases for partitioning potential seismic sources, analyzing the seismotectonics and estimating location of strong earthquakes.Due to the nonuniformity of earth media, instability of observation systems and disturbance of the environment, etc, the variety of observational data is complicated, that is, there is no absolutely "normal" or "abnormal", and seismic anomalies can be divided into many mutually exclusive "abnormal states". In different conditions of combined time-space-strength, determining seismic anomalies by different monomial forecast methods and its efficiency could be different due to the uncertainty of a precursor itself or complexity of the relationship between a precursor and earthquake gestation. It is very difficult to discover and dispose of this difference in actual application in a "two-state" model. But in a "multi-state" model, the difference can be easily reflected and the optimal combination of forecasting parameters for a forecast method can also be determined easily.Based on the "multi-state" precursory model and the optimization method for parameters of earthquake forecast model under the condition of optimal forecast efficiency, the relationship of the spatial location of earthquake with M≥6.0 and active faults in three seismic belts are analyzed. The results demonstrate that in the Hetao Seismic Belt, seismicity is mostly concentrated in the range of 20 km along the fault, the optimization model can forecast the location of potential earthquakes of M≥6.0 near the faults with a relatively high accuracy and the reliability is 0.5; while in the Qilian Mt. Seismic Belt, the reliability only reaches 0.14 when we use the model to estimate earthquakes within 30 km range along the faults. The "multi-state" precursory model, the efficiency-evaluating model and the parameter selection of individual earthquake forecast model based on optimal efficiency are of certain revelatory and practicable meanings for developing knowledge about precursors, investigating the laws of earthquake preparation and searching for optimal forecasting methods.     

A method for automatic history matching of a compositional reservoir simulator with multipoint flux approximation

A method for history matching of an in-house petroleum reservoir compositional simulator with multipoint flux approximation is presented. This method is used for the estimation of unknown reservoir parameters, such as permeability and porosity, based on production data and inverted seismic data. The limited-memory Broyden–Fletcher–Goldfarb–Shanno method is employed for minimization of the objective function, which represents the difference between simulated and observed data. In this work, we present the key features of the algorithm for calculations of the gradients of the objective function based on adjoint variables. The test example shows that the method is applicable to cases with anisotropic permeability fields, multipoint flux approximation, and arbitrary fluid compositions.     

云母分子式计算方案的选择

本文借助主成分分析证明了花岗岩类中黑云母的Fe~(3+)、Fe~(2+)和(OH+F)主要的数量关系不表现为氧羟铁云母置换,还讨论了水不足和水过剩对云母分子式计算结果的影响,进而提出了当处理一批未受明显脱羟基氧化的云母,尤其是当其中包括明显水过剩云母时,宜优先采用O=22计算分子式方案等建议。     

高阜工业园区土地平整土方量计算

土方量的计算方法有方格网法、断面法、等高线法及基于DEM的计算方法等。为了计算高阜工业园区的土方量,本文采用了方格网法;并重点讨论了在不同坡度下,得到的不同土方量计算结果;最后根据测区需要,做出合理选择。     

Reliability assessment of mooring lines for floating structures considering statistical parameter uncertainties

This work focuses on the effect of parameter uncertainty on the reliability index and on the predictive reliability of mooring lines for floating structures under loading from extreme sea-states. A first-order analytic formulation is developed which takes into consideration uncertain parameters in the statistical models of the maximum dynamic tension and the breaking resistance of the mooring lines. Expressions are derived for the mean and the variance of the reliability index in terms of the mean values and the covariance matrix of the uncertain parameters, and of the sensitivity of the reliability index to the uncertain parameters. The predictive reliability index is expressed in terms of the mean and the variance of the reliability index. The formulation is applied to case studies of catenary and taut-leg mooring lines of an offshore structure and the relative effects of the sources of statistical uncertainty are assessed. The case studies demonstrated the applicability and capability of the formulation to capture and represent the relative contributions of the different sources of uncertainty on the predictive reliability and predictive failure probability, as well as on the statistics of the uncertain reliability index.     

An Overview of Measurement and Calculation Methods on the Land Surface Temperature on Alpine Mountainous Cold Regions

Land surface temperature on alpine mountainous cold regions, which is one of basic parameters of the regional hydrological and meteorological conditions, directly affects glacial recession, snow melt, distribution and freezing thawing process of permafrost, evapotranspiration, vegetation growth, and various underlying surface change process, and then changes the regional hydrological and ecological environment, becomes the important parameter of the research on land surface process and the study of eco-hydrological process. This paper tried to provide an overview of research on land surface temperature, and to introduce its influence factors and the ways to obtain land surface temperature data in high mountainous cold region. Relative to low elevation plain, the land surface temperature was significantly affected by local altitude, terrain and plant cover. There were some methods to obtain land surface temperature, such as measurement in situ, retrieval based on remote sensing and calculation by land surface process models, but there were some limitations while used on alpine mountainous cold regions. Land surface temperature data from meteorological stations were only about level bare ground, and the influence of terrain or vegetable cover was not considered. Therefore, the data could not represent the information of region scale on mountainous area. Land surface temperature retrieval from remote sensing data, because of calculation theory, ground observation verification and spatiotemporal resolution, made it difficult to fulfill research on hydrology, land surface process and eco-hydrological process in alpine mountainous area. Land surface process models estimated land surface temperature in the experimental sites with high accuracy, but reduced the accuracy while upscale to the region scale on the mountainous cold area, because of the error from input control meteorological, soil and plant variables, and the error of ground observation site verification. The future research on land surface temperature on alpine mountainous cold regions should strengthen field observations and improve data accuracy, to build a physical land surface temperature estimation method with topographic and vegetation parameters, and to contribute to research on land-atmosphere-water process in alpine mountainous regions.     

Measures to diminish the parameter drift in the modeling of ship manoeuvring using system identification

System identification provides an effective way to predict the ship manoeuvrability. In this paper several measures are proposed to diminish the parameter drift in the parametric identification of ship manoeuvring models. The drift of linear hydrodynamic coefficients can be accounted for from the point of view of dynamic cancellation, while the drift of nonlinear hydrodynamic coefficients is explained from the point of view of regression analysis. To diminish the parameter drift, reconstruction of the samples and modification of the mathematical model of ship manoeuvring motion are carried out. Difference method and the method of additional excitation are proposed to reconstruct the samples. Using correlation analysis, the structure of a manoeuvring model is simplified. Combined with the measures proposed, support vector machines based identification is employed to determine the hydrodynamic coefficients in a modified Abkowitz model. Experimental data from the free-running model tests of a KVLCC2 ship are analyzed and the hydrodynamic coefficients are identified. Based on the regressive model, simulation of manoeuvres is conducted. Comparison between the simulation results and the experimental results demonstrates the validity of the proposed measures.     

CICE海冰模式中反照率相关参数对北极海冰模拟的影响

国家气候中心气候系统模式BCC_CSM2.0最新耦合了美国Los Alamos国家实验室发展的海冰模式CICE5.0,为试验模式中与反照率相关参数的敏感性及其对模拟结果的影响,提高模式对北极海冰的模拟能力,选取海冰模式中3个主要参数进行了敏感性试验。利用以BCC_CSM2.0耦合框架为基础建立的海冰-海洋耦合模式,选取CORE资料为大气强迫场开展试验,试验的3个参数分别为冰/雪表面反射率、雪粒半径和雪粒半径参考温度。结果表明,参数取值的不同对北极海冰的模拟有显著的影响,优化后的取值组合极大提高了模式的模拟能力,主要表现在:（1）改善了对北极冬季海冰厚度的模拟,海冰厚度增大,与观测资料更为吻合;（2）显著提高了对北极夏季海冰密集度的模拟能力,从而模拟的北极海冰范围年际循环与观测更为一致。参数取值的优化改进了模式对海冰反照率的模拟,进而影响了冰面短波辐射的吸收和海冰表层的融化,最终提高了模式对海冰密集度和厚度的模拟效果。      

平均风向的计算方法及其比较

常用的平均风向４种计算方法分别是算术平均法，标量平均法，单位矢量法和矢量法，利用则资料对各种方法的计算结果进行比较，结果表明：算术平均法加大了偏南风的比重，标 在风向变化３６０°时有可能出现较大的误差，在应用时间须加以注意；单位矢量法与矢量法的结果比较一致，且不需风速的同期观测资料，是一种比较好的方法。     

澳门地质概况

对澳门的泥盆系、第三系、第四系地层出露作了叙述，说明了花岗闪长岩、黑云母粗粒花岗石等几篑夺浆岩的分布及岩性特征，详细地论述了区内８条断裂构造，概述了碎石、建筑材料等矿产资料。