中心回线瞬变电磁法观测二次电位误差对计算全期视电阻率的影响研究

通过对均匀半空间中心回线装置瞬变电磁法核函数的研究,推导了中心回线瞬变电磁法观测二次电位误差对计算全期视电阻率的影响的表达式,发现在晚期微小的二次电位的误差将比早期对视电阻率的计算的影响更大,并介绍了目前对提高早晚期数据采集与处理质量的方法技术。     

复杂地形地质条件下矿井富水性探测技术与应用

黄土塬区地形地质条件复杂,运用瞬变电磁法开展矿井水探测能取得较好效果。在试验基础上,获取了测区大定源回线装置最佳发射框尺寸、发射频率及供电电流等参数,并将其运用于有效性试验,获得了区内视电阻率分布特征。实验区视电阻率三维切片图表明:煤系地层中不连续分布的低阻异常,推断为巷道分布位置;由于顶板冒落,裂隙可能导通上部砂岩含水层,建议开采前采取有效的探放水措施。     

井中瞬变电磁全区视电阻率解释方法研究

针对井中瞬变电磁全区视电阻率定义求解和解释方法开展研究。依据均质全空间瞬变电磁场解析式计算不同采样时间或装置条件下感应电压响应,认识到响应值在电阻率取值范围的全区间或部分区间内保持单调性。根据"牛顿-下降"最优化原理,给出一种井中瞬变电磁全区视电阻率求解方法,通过均质全空间瞬变电磁场响应试算结果与介质真电阻率对比验证该方法的精度和适用性。建立典型径向及垂向分层地电介质模型,通过时域有限差分法模拟计算瞬态场感应电压响应,并进行全区视电阻率换算分析。结果表明:视电阻率是不同时刻电磁场作用范围内所有电性体的综合反映,由全时段视电阻率结果识别全空间介质的径向及垂向电性情况具有一定可行性,各时道的视电阻率值可作为推断地电结构等信息的依据。     

基于全区视电阻率瞬变电磁一维正演中滤波系数的选取

为提高瞬变电磁正反演数值计算的效果和效率,选取合适的数值滤波系数是关键.通过建立参照模型,选用正演数值计算效果良好的3组汉克尔变换滤波系数和3组余弦变换滤波系数,对比分析了其不同组合正演的计算效率、精度和有效范围.利用瞬变响应的平移伸缩特性提出参数模型法,实现了针对实测数据的滤波系数选取的估算,经过反演测试,最终得出了基于全区视电阻率的最佳滤波系数组合.     

均匀半空间中心回线瞬变电磁法正演研究

通过对均匀半空间中心回线装置瞬变电磁法表达式分析,可以为瞬变电磁法的反演提供理论正演数据、可以为瞬变电磁法的反演提供一定的方法,同时还可以为野外生产设计与室内数据筛选与剔除提供一定的参考。通过一个反演实例说明在晚期微小的二次电位误差将对视电阻率的计算会产生很大的影响,并编制了matlab程序计算各种工作装置和视电阻率理论正演二次电位衰减到噪声影响程度高的准确时间,对工程设计、评价视电阻计算的准确度及剔除受噪声影响严重的数据有一定的参考性。     

矿井瞬变电磁传统视电阻率算法的可靠性分析

矿井瞬变电磁已普遍应用于我国各大矿区的水害探查。由于适用于矿井探测空间的视电阻率算法在大量数据处理平台中还未得到及时更新,很多矿方技术人员仍在沿用传统的地面视电阻率算法,其结果的可靠性值得探讨。通过将水平电偶极子产生的瞬变电磁场沿发射回线的路径进行积分,并基于磁矩等效原理,推导了矿井空间条件下的多匝方形回线瞬变电磁场响应公式,与数值计算结果进行对比,确定其最大误差为1.5%,证明该公式是准确的。利用相同测试参数条件下矿井与地面瞬变电磁场的对比,确定前者的响应幅值为后者的2.5倍,相应的视电阻率比值为1.842,进一步表明传统的地面视电阻率值与矿井视电阻率值之间仅存在固定的比例关系,对视电阻率的趋势特征并未改变,可认为传统视电阻率算法相对可靠,对现场勘探解释的影响较小。     

瞬变电磁法超前预报全空间解释技术研究

瞬变电磁法超前预报技术是预测井下突水构造的有效方法之一,其资料解释方法为地下瞬变电磁法理论体系的重要组成部分.从应用的角度出发对全空间资料解释的理论基础及传统解释方法的精确性进行分析,进而将全空间解释方法应用于井下超前预报实测资料的处理.结果表明,全空间视电阻率和视深度为半空间的某一倍数.半空间晚期视电阻率值在各个采样时刻与真值的相对误差均大于40％,当以精确视电阻率公式和全空间深度公式为标准时,采用半空间深度公式计算误差范围为45.50％ ～50.88％.全空间晚期视电阻率与真值的误差小于8.74％,进而由此计算的深度与标准值的最大相对误差仅为3.97％.将全空间全区视电阻率公式和深度计算公式应用于矿井突水构造的超前探测,取得了令人满意的效果.     

埋地管道腐蚀的成像检测技术研究

根据瞬变电磁全区视电阻率的数值计算方法,以及基于烟圈效应下的反演深度求解,提出了基于埋地管道的视电阻率成像解释的思路.研制出了埋地管道腐蚀成像检测的程序,该程序能确定腐蚀大小和位置,通过野外实例的应用.获得了良好的效果,证明了该方法技术和程序的有效性及实用性,这也为管道的正常运行提供了安全保障.     

中心回线瞬变电磁自适应正则化反演

采用自适应正则化反演,直接对瞬变电磁感应电动势曲线进行反演拟合。相对于传统的求取视电阻率进行定性或半定量的解释方法,利用自适应正则化反演技术可更为准确的获得地电断面的电阻率分布。通过理论模型试算表明自适应正则化反演算法收敛快速、拟合效果好,一般只需迭代5次反演就趋于稳定,迭代10次后目标函数即可达到5×10-2。对某煤矿区的中心回线装置瞬变电磁资料进行反演,和已知资料吻合较好,验证了自适应正则化反演算法可以很好的应用于瞬变电磁资料解释中。     

水平电偶源频率域电磁测深全区视电阻率的直接算法

利用水平电偶源激发的电磁场，提出了直接精确计算全区视电阻率的方法．计算和分析结果表明，该方法的结果在远区等价于卡尼亚电阻率，在近区和过渡带则明显地改善了卡尼亚电阻率的非波区场畸变，从而能更好地接近基底的真电阻率，更形象地反映了地下介质的垂向电性变化．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the