基于交会图和多元统计法的神经网络技术在火山岩识别中的应用

针对火山岩储层的特殊性(复杂性、离散性和随机性),应用BP神经网络技术对火山岩测井解释中岩性识别问题进行了研究。该方法的技术关键是样本集和初始权重的建立,以及模型的优选。本文提出了一种基于交会图和多元统计法的学习样本生成方法,即根据取心岩样的地球化学和岩石学研究,用交会图技术建立样本集,采用聚类分析和距离判别法确定初始权重。将研究方法应用在松辽盆地杏山地区火山岩岩性识别问题中,取得了很好的效果,岩性解释符合率高于90%。文中通过四种岩性识别处理模式的对比研究,表明赋权重处理模式为最优处理模型。在神经网络模型预测过程中,需充分利用已有的地质经验和测井曲线信息建立典型可靠的样本文件,同时考虑神经网络方法中各种因素的影响,优选模型和计算参数才能使预测结果符合实际情况。     

松辽盆地南部深层火山岩识别及成藏条件分析

松辽盆地北部徐深1井在营城组火山岩获得油气突破后，在松辽盆地南部长岭断陷针对火山岩部署了长深1井。在长深1井营城组火山岩地层测试获4.6×105m3/d的工业气流，推算无阻流量1.5×106m3/d以上，预示松辽盆地南部深层火山岩气藏是下步勘探开发的主要领域。通过大量的火山岩岩心资料，利用岩石学、矿物学、测井和地震地层学等多学科技术，首次在松辽盆地南部建立了火山岩识别标准，在东南隆起区部署探井1口，在火山岩中见到了较好的气显示，取得很好的效果。     

徐深气田兴城开发区营一段火山岩气藏岩性岩相研究

徐深气田兴城开发区营城组一段火山岩气藏位于松辽盆地北部徐家围子断陷升平-兴城构造带上，储层以酸性火山岩为主，可分为火山熔岩和火山角砾岩两大类。岩相类型有爆发相、溢流相、火山沉积相、火山通道相和侵出相五种类型，其中爆发相和溢流相分布范围广、物性好。是有利的储集相带。根据地震反射参数，从内部反射结构和外部几何形态出发，结合反射同相轴的振幅和连续性，在地震反射剖面上识别出丘状、楔状、亚平行状、柱状和伞状五种地震相类型，这些地震相类型与对应井点处单井相解释结果一致，与岩相类型对应关系明确。在剖面相准确识别的基础上，编制火山岩相平面分布图，为优选建产区块和部署开发井位提供依据。     

Formation of geothermal resources at lithospheric subduction zones

This paper examines in a very broad fashion the formation of geothermal resources at lithospheric subduction zones. Regions of highly silicic calc-alkaline Quaternary volcanoes and/or plutons have been identified as prime candidates for having high-temperature hydrothermal systems. Regions of large tholeiitic Quaternary volcanoes have been identified as prime candidates for having large moderate-temperature hydrothermal systems. In addition, active magmatic, phreatomagnetic, and/or tectonic fracturing must be occurring in order to keep any moderate to high temperature hydrothermal system from chemically sealing. Connate, meteoric and/or oceanic water sources must also be present. Owing to tectonic and magmatic processes, volcanic arcs of subduction zones represent regions of the crust that have anomalously high mechanical and heat energy. Such arc regions are expected to contain significantly more moderate to high temperature hydrothermal systems than what is presently known. Many of these arcs are briefly discussed with respect to their potential for containing such resources.     

Strength, durability and micro-structural aspects of high performance volcanic ash concrete

This paper presents the results of investigations to assess the suitability of using volcanic ash (VA) as a cement replacement material to produce high performance concrete. Tests were conducted on concrete mixtures replacing 0 to 20% by mass of ordinary Portland cement (OPC) by VA. The performance of high performance volcanic ash concrete (HPVAC) mixtures was evaluated by conducting comprehensive series of tests on fresh and hardened properties as well as durability. The mechanical properties were assessed by compressive strength, while durability characteristics were investigated by rapid chloride permeability (RCP), drying shrinkage (DS), mercury intrusion porosimetry (MIP), differential scanning calorimetry (DSC) and microhardness tests. HPVACs showed better durability properties compared to control concrete with 0% VA. The improved performance of HPVACs was attributed to the refinement of pore structure, and pozzolanic action of VA. HPVAC having a minimum 28-day compressive strength of 60 MPa can be obtained by replacing up to 20% (by mass) of cement by VA. Development of non-expensive and environmentally friendly HPVAC with acceptable strength and durability characteristics (as illustrated in this study) is extremely helpful for the sustainable development and rehabilitation of volcanic disaster areas around the world.     

叠合盆地油气成藏体系研究方法探讨

应用三维模拟技术,强化油气成藏体系动态演化过程,采用正反演结合的思路,探讨叠合盆地油气成藏体系的研究思路和方法。研究过程分五步:通过成藏要素研究构建地质模型;通过正演烃源岩生烃过程与时空演化,分阶段计算生烃量;通过输导体系研究来调整油气最终的分布;应用油气组分追踪技术分析不同烃源岩层贡献比例;根据三维模拟结果动态分析资源空间分布及变化过程。     

A Thermo-Mechanical Study of Some Epoxy Adhesives Subjected to Combined Dynamic and Static Stresses

The object of the present study was to investigate the effect of superimposed dynamic and static stresses on mechanical and thermal properties of some epoxy adhesives. It was found that combinations of shear creep and torsional oscillations, applied simultaneously to adhesive joints at temperatures within the glassy range of the adhesive, led to strengthening of the joints in shear and to an increase in the glass transition temperature of the adhesive. Similar loading stresses applied at temperatures close to the T_g of the adhesive, led to opposite effects on the above mentioned properties of the joints. The width of the glassy-rubbery transition of the adhesives increased, in the whole range of temperatures used in this study and for all epoxy compositions, as a result of subjecting the joints to superimposed dynamic and static stresses. The broadening of the glass transition was interpreted as a result of the stiffening of polymer network during the combined stressing experiments. A linear relationship was found between the area of endothermal peaks in the first DSC scan of specimens subjected prior to test to superimposed dynamic and static stresses at temperatures below T_g, and the shear strength of the joints. In agreement with this observation and with literature data, a linear relationship was revealed also between the glass transition temperature of the resins (measured in the first DSC scan) and the shear strength of the joints. Based on experimental observations and on some literature information, it was suggested that the strengthening of the joint, as well as the changes in thermal properties of the adhesives, are mainly due to physical processes, such as short-range orientation of network chains and an increase in intermolecular interaction between highly polar sites of the network. The possibility that superimposed stressing led to changes in chemical crosslinking was discussed but it seems that no such reactions occurred.     

叠合式双向板试验与数值模拟对比分析

针对传统双向板与两拼、三拼叠合式双向板用ABAQUS进行有限元非线性模拟分析,对比这三种双向板的挠度、钢筋应变以及裂缝开展等方面差别。结果表明与传统双向板比较这种两拼叠合式双向板在受力性能上基本相同,最后总结两拼叠合式双向板在受力时的状态,并提出改进建议以及还需解决的问题,从而为叠合式剪力墙板结构技术规程的完善提供理论依据,为其能够广泛应用于高层建筑的施工建设提供技术支持和理论支撑。     

基于补偿电压突变量的一种实用快速故障选相判据

论述突变量选相应用于（超）高压电力系统的必要性,分析补偿电压突变量的优良特性,并指出现有基于补偿电压突变量的选相判据存在不足。在分析补偿电压突变量在不同故障情况下的特征基础上,基于＆quot;突变量元件＆quot;提出新的选相判据,该判据将突变量与接近于零的固定门槛值进行比较,解决了故障初期因突变相量未完全形成而造成选相不准确的问题。RTDS仿真结果表明补偿电压突变量选相可以在故障发生后快速、准确的选出故障相。     

Compressed sensing of superimposed chirps with adaptive dictionary refinement

The compressed sensing （CS） theory shows that accurate signal reconstruction depends on presetting an appropriate signal sparsifying dictionary. For CS of superimposed chirps, this dictionary is typically taken to be a waveform-matched dictionary formed by blindly diseretizing the frequency-chirp rate plane. However, since practical target parameters do not lie exactly on gridding points of the assumed dictionary, there is always mismatch between the assumed and the actual sparsifying dictionaries, which will cause the performance of conventional CS reconstruction methods to degrade considerably. To address this, we model the waveform- matched sparsifying dictionary as a parameterized one by treating its sampled frequency-chirp rate grid points as the underlying parameters. As a consequence, the sparsifying dictionary becomes refinable and its refinement can be achieved by optimizing the underlying parameters. Based on this, we develop a novel reconstruction algorithm for CS of superimposed chirps by utilizing the variational expectation-maximization （EM） algorithm. By alternating between steps of sparse coefficients estimation and dictionary parameters optimization, the algorithm integrates the process for dictionary refinement into that of signal reconstruction, and thus can achieve sparse reconstruction and dictionary optimization simultaneously. Experimental results demonstrate that the algorithm effectively deals with the performance degradation incurred by dictionary mismatch, and also outperforms the state-of-the-art CS reconstruction methods both in compressing the signal measurements and in suppressing the measurement noise.