基于案例推理的电力设备多故障诊断方法

在分析多故障模式特点的基础上,建立了面向多故障的案例知识库,并提出了一种基于二次检索策略的电力设备多故障诊断方法.采用基于权重隶属度的候选案例生成方法对案例库进行初步检索,有效地减少了候选案例的数量.通过灰色关联分析对案例相似度进行计算,获得最有可能发生的故障案例,避免了多故障组合爆炸所带来的大计算量问题.最后通过实例对所提出的方法进行了说明.     

地质灾害治理工程的特殊性风险性及治理工程风险事件实例分析

地质灾害治理工程有其自身的独特性,不同于一般工民建等建设工程,它是地质工程中的特殊类型,是对不稳定地质体实施改造的防灾地质工程。文章论述了地质灾害治理工程的特殊性、技术风险性及风险源。风险源可分为客观风险源和主观风险源。客观风险源主要源出于地质灾害系统客观存在的即固有的复杂性和不确定性;主观风险源主要出自于勘查设计单位的能力与水平、行政干预及对设计审查的程序和水平。文章对三峡库区二期地质灾害治理工程已发生的风险事件实例进行了简要阐述与分析。     

土工袋加固地基原理及其工程应用

介绍土工袋加固地基的原理、基本特性,及其在房屋地基加固、路基加固、堤防加固及构筑挡墙等非膨胀土地基中的工程应用实例与处理膨胀土地基的应用可能性。     

Background seismicity in the Central Apennines of Italy: The Abruzzo region case study

We investigate background seismic activity of the Abruzzo region, a 5000 km² area located within the Central Apennines of Italy, where in the past 600 years at least 5 large earthquakes (I = XI–X) have occurred.Between April 2003 and September 2004, a dense temporary seismic network composed of 30 digital three-component seismic stations recorded 850 earthquakes with 0.9 < M_L < 3.7. We present earthquake locations and focal mechanisms obtained by standard procedures and an optimized velocity model computed with a search technique based on genetic algorithms.The seismicity occurs at a low and constant rate of  2.6 e− 04 events/daykm² and is sparsely distributed within the first 15 km of the crust. Minor increases in the seismicity rate are related to the occurrence of small and localised seismic sequences that occur at the tip of major active normal faults along secondary structures.We observe that during the 16 months of study period, the Fucino fault system responsible for the 1915 Fucino earthquake (M_S = 7.0), and the major normal faults of the area, did not produce significant seismic activity.Fault plane solutions evaluated using P-wave polarity data show the predominance of normal faulting mechanisms ( 55%) with NE-trending direction of extension coherent with the regional stress field active in this sector of the Apennines. Around 27% of the focal solutions have pure strike–slip mechanisms and the rest shows transtensional faulting mechanisms that mainly characterise the kinematics of the secondary structures activated by the small sequences.We hypothesize that the largest known NW-trending normal faults are presently locked and we propose that in the case of activation, the secondary structures located at their tips may act as transfer faults accommodating a minor part of the extensional deformation with strike–slip motion.     

TPC 及 DLC理论在旅游产品再开发中的应用——昆明市案例研究

从旅游产品再开发的角度出发,应用市场营销学的TPC理论和旅游地理学的DLC理论,对昆明市的病例进行分析,提出了昆明市旅游产品再开发战略的方向、原则和发展重点。     

Compaction of diagenetically altered mudstones – Part 2: Implications for pore pressure estimation

Diagenetically altered mudstones compact mechanically and chemically. Consequently, their normal compaction trends depend upon their temperature history as well as on the maximum effective stress they have experienced. A further complication is that mudstones are commonly overpressured where clay diagenesis occurs, preventing direct observation of the hydrostatic normal compaction trend. A popular way to estimate pore pressure in these circumstances is to calculate the sonic normal compaction trend in a well with a known pressure–depth profile by applying Eaton's method in reverse, and then to estimate pore pressure in offset wells using Eaton's method conventionally. We tested this procedure for Cretaceous mudstones at Haltenbanken. The results were inconsistent because the sonic log responds differently to disequilibrium compaction overpressure and unloading overpressure, and their relative contributions vary across the basin. In theory, a two-step method using the density and sonic logs could estimate the contributions to overpressure from disequilibrium compaction and unloading. The normal compaction trend for density should be the normal compaction trend at the maximum effective stress the mudstones have experienced, not at hydrostatic effective stress. We advocate the Budge-Fudge approach as a starting point for pore pressure estimation in diagenetically altered mudstones, a two-step method that requires geological input to help estimate the overpressure contribution from disequilibrium compaction. In principle, the Budge-Fudge approach could be used to estimate the normal compaction trend for mudstones at the maximum effective stress they have experienced, and so form the basis of the full two-step method through the use of offset wells. Our initial efforts to implement the full two-step method in this way at Haltenbanken produced inconsistent results with fluctuations in estimated pore pressure reflecting some of the fluctuations in the density logs. We suspect that variations in the mineralogical composition of the mudstones are responsible.     

Growth and linkage of a segmented normal fault zone; the Late Jurassic Murchison–Statfjord North Fault, northern North Sea

The structure of the 25 km long northeastern portion of the Murchison–Statfjord North Fault Zone and adjacent syn-rift stratigraphy are integrated to reconstruct the temporal and spatial evolution during c. 30.5 myr of Late Jurassic, North Sea rifting. Based on a structural analysis (D–d data) alone, approximately 14 precursor fault strands are identified. Incorporation of stratigraphic data shows that only six of these strands were important in controlling stratal architecture and distribution. Three main stages in the evolution of the fault zone are recorded in the syn-rift stratigraphy and are biostratigraphically constrained. These are: (1) following initiation of rifting, six isolated fault strands developed (each <4 km long) and controlled the stratigraphy for c. 13 myr; (2) the isolated strands linked along-strike forming two >9 km long fault segments separated by a 2 km wide relay ramp, that controlled the stratigraphy for at least the following c. 10.5 myr; and (3) the two fault segments hard-linked forming a single, continuous fault trace during the final c. 7 myr of rifting. The results of this study reveal the necessity to adopt an integrated structural and stratigraphic approach when reconstructing the evolution of normal fault zones. The results may also help to further constrain models of fault evolution.     

Earthquake Prediction Research in China

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Modelling of Seasonal Evapotranspiration from an Agricultural Field Using the Canadian Land Surface Scheme (CLASS) with a Pedotransfer Rule and Multicriteria Optimization

The performance of the Canadian Land Surface Scheme (CLASS 3.5) was assessed using turbulent fluxes derived from data recorded at two micrometeorological stations located in a potato field in Quebec, Canada. The minimum stomatal resistance, the maximum leaf area index, and the initial water content of the third soil layer were optimized using the Non-Dominated Sorting Genetic Algorithm-II and the mean square error of the latent heat flux. With respect to benchmark solutions, the optimization improved the sensible and latent heat fluxes by 31 and 23%, respectively. The use of a pedotransfer rule in adjustment of the water content of mineral soils having small percentages of organic matter provided better estimates of the evapotranspiration during the growing stage. However, like the original version of the model (without the pedotransfer rule), it underestimated evapotranspiration throughout the maturity stage. It is noteworthy that the original version produced a good estimate of cumulative evapotranspiration over the entire season as a result of over- and underestimates at the beginning and maturity stage of the growing season, respectively.     

共有建筑面积分摊的城市综合体功能区划分方法

功能区划分直接影响分摊结果,进而影响房产面积的真实性和可靠性。建筑空间或综合体的结构、服务功能、使用对象交织错落,增加了功能区划分的复杂性。本文对一个城市综合体进行了案例分析,提出了共有面积中功能区服务范围为主、用途为辅的划分方法。