综合物探技术在矿山水文地质勘探中的应用

井下水文地址勘探一直是煤矿矿山采掘领域的技术难题,对矿山开采安全具有重要的保障作用。针对芦沟矿周边水文地质勘探出现的不明情况,利用地震勘探加上瞬变电磁物探技术组合方式,对芦沟矿周边水文地质环境进行了详细勘探。为保障勘探结果能够相印证,在垂直于地层的方向布设了多条重合测量线。通过多勘探结果可以看出：2种勘探技术结果相似度比较高,能够对煤矿开采影响比较大的岩层富水区与断层实现精准勘探。     

高阳煤矿201工作面瞬变电磁法探测顶底板富水区中的应用

高阳煤矿采用中国地质大学(武汉)高科资源探测仪器研究所生产的TEMHZ75矿用本安型瞬变电磁仪和TEMJF50矿用隔爆兼本安型瞬变电磁仪组合实现大功率瞬变电磁法对新201工作面进行对穿检测,为富水区水害治理和煤层开采提供物理探测技术依据。后期验证结果证明探测结果准确,为水患治理提供重要依据。     

瞬变电磁仪在探测采空区积水的应用

瞬变电磁仪是近年来发展很快的一种电法物探方法,目前矿井使用的瞬变电磁仪具有小型轻便、测量精度高、自动化程度高、抗干扰能力强、探测信息量大等特点。文章论述了瞬变电磁仪的基本工作原理和资料解释的方法,介绍了这种方法在探测采空区积水的应用。     

瞬变电磁法在煤矿井下探水中的应用

介绍了井下瞬变电磁技术的探测原理、特点和施工方法,总结得出瞬变电磁法在探测煤矿掘进头前方的富水位置方面是非常有效的,为煤矿的安全生产提供了重要的依据。     

三维地震结合瞬变电磁在石灰岩地区的应用

矿井在石灰岩地层中掘进时极易遇到溶洞、暗河等不良地质现象,采用三维地震结合瞬变电磁法在地面对溶洞、暗河的分布情况进行探测,判定溶洞的含水性,为矿井在石灰岩地层掘进提供技术依据,确保矿井安全。     

煤田地震勘探中特殊地质异常体的识别及应用研究

煤田三维地震勘探方法在确定地质异常体过程中扮演着非常重要的角色。文章细致深入地探讨了煤矿生产过程中的地质异常体基本状况,在此基础上,对比分析了煤矿现状描述和三维地震勘探资料两个方面的内容,以期为相关研究提供借鉴。     

大定源瞬变电磁法在陕西某煤矿中的应用

完整岩层的电阻率相对较高,但当其中一部分出现断裂、构造缝隙等情况时,其电阻率就会随之出现明显的变化。岩石物质的含水量会直接影响其电阻率,而大定源瞬变电磁法利用地质体和围岩存在的电性差异,为探测含水岩层分布、导含水构造以及采区域积水提供了物理条件。     

应用瞬变电磁技术探测煤层底板岩溶水的研究

瞬变电磁技术具有探测准确性高,能够有效探测低阻含水岩体等优点,使得该技术在煤层底板岩溶水探测中得到了较为广泛的应用。分析总结了瞬变电磁技术在某煤矿各矿井应用的情况。     

综合物探技术在引水隧洞工程超前地质预报中的应用

由于各种超前地质预报方法都存在一定的局限性,选择适宜的超前地质预报方法及地表探测方法相组合,可以提高超前地质预报的精确性与经济性。通过分析常用的超前地质预报方法及地表探测方法的优缺点,判断其适用范围,并在某引水工程实例中,根据其施工特点,洞内采用地震波法和激发极化法,洞外采用大地电磁法的长短结合、内外结合的探测方案,准确预报了掌子面前方80 m内的破碎、含水岩体及80～350 m的含水背斜构造,指导施工,有效避免了相关风险,提高了超前地质预报的精确性与经济性,可为综合探测方案的选择提供参考。     

使用ParaView实现地面瞬变电磁法三维可视化

为了准确探查高速公路采空区位置,指导矿方对公路采空区的治理工作,避免造成不必要的灾害,使用ParaView软件对地面瞬变电磁法的探测结果进行三维展示。该方法在山东省淄博市临淄金龙铁矿矿区的高速公路段试用,经钻探验证,该软件能有效显示异常区,精准指导矿方。     

BWZ-250/50型泡沫水泵增压装置在煤田地质勘探中的应用

首次采用自行研制的配套泡沫灌注系统在福建东中煤矿进行了金刚石泡沫绳索取心钻探试验，该灌注系统设计孔深为1000m。通过对泡沫堵漏机理的分析说明了泡沫在漏失地层钻探中的可行性，对现场实例分析了试验中获得的钻进时效，从而探讨了影响压降的几个关键问题。基本摸索了煤田泡沫金刚石绳索取心钻进的基本钻进工艺参数。     

Non-destructive monitoring of early stages of white rot by Trametes versicolor in Fraxinus excelsior

? Non-destructive detection of fungal decay in living trees is relevant for forest management of valuable species, hazard tree assessment, and research in forest pathology. A variety of tomographic methods, based on stress wave timing, radioactive radiation, or electrical resistivity have been used to detect decay in standing trees non-destructively. But apart from mobile gamma ray computed tomography (Habermehl and Ridder, 1993) which is virtually unavailable, the detection of incipient stages of decay is still not possible.

? Wood moisture and electrolyte content influence the electric resistivity of wood. Both are changed by fungal decay. Therefore electric resistivity tomography (ERT) should detect decay in its early stages. Then it could be used to monitor the spatial and temporal progress of degradation.

? We infected four Fraxinus excelsior trees with Trametes versicolor using wooden dowels and measured two-dimensional electric resistivity tomograms 3, 10, 13 and 21 months after infection. Immediately after the last electric resistivity measurement trees were felled for further analyses of stem cross-sections. Wood moisture content and raw density had significantly increased in infected areas, but dry density had not significantly changed after 21 months. Areas of very low electric resistivity around the infected wounds correlated very well with infected wood in the stem cross-sections. Increasing areas of low electric resistivity around the infected wounds during consecutive measurements indicate increasing areas of infected wood.

? We conclude that the growth of white rot by Trametes versicolor can be monitored with electric resistivity tomography (ERT) beginning from incipient stages, even before wood density decreases. ERT could therefore be a powerful research tool for decay dynamics as well as a method for diagnosing wood decay in forestry and arboriculture.

     

In situ detection of tree root distribution and biomass by multi-electrode resistivity imaging

Traditional methods for studying tree roots are destructive and labor intensive, but available nondestructive techniques are applicable only to small scale studies or are strongly limited by soil conditions and root size. Soil electrical resistivity measured by geoelectrical methods has the potential to detect belowground plant structures, but quantitative relationships of these measurements with root traits have not been assessed. We tested the ability of two-dimensional (2-D) DC resistivity tomography to detect the spatial variability of roots and to quantify their biomass in a tree stand. A high-resolution resistivity tomogram was generated along a 11.75 m transect under an Alnus glutinosa (L.) Gaertn. stand based on an alpha-Wenner configuration with 48 electrodes spaced 0.25 m apart. Data were processed by a 2-D finite-element inversion algorithm, and corrected for soil temperature. Data acquisition, inversion and imaging were completed in the field within 60 min. Root dry mass per unit soil volume (root mass density, RMD) was measured destructively on soil samples collected to a depth of 1.05 m. Soil sand, silt, clay and organic matter contents, electrical conductivity, water content and pH were measured on a subset of samples. The spatial pattern of soil resistivity closely matched the spatial distribution of RMD. Multiple linear regression showed that only RMD and soil water content were related to soil resistivity along the transect. Regression analysis of RMD against soil resistivity revealed a highly significant logistic relationship (n = 97), which was confirmed on a separate dataset (n = 67), showing that soil resistivity was quantitatively related to belowground tree root biomass. This relationship provides a basis for developing quick nondestructive methods for detecting root distribution and quantifying root biomass, as well as for optimizing sampling strategies for studying root-driven phenomena.     

竹材液化物碳纤维的电学性能研究

使用万用电表、X射线衍射仪等仪器对竹材液化物碳纤维的电阻率、XRD结构参数等进行测量,初步研究了竹材液化物碳纤维电阻率随炭化温度、炭化时间以及XRD结构参数的变化规律,为进一步探讨其导电机理、导电性能以及将其作为电磁屏蔽材料提供基础数据.     

竹炭理化性能的测试和分析

参考相关国家标准,对浙江省18家竹炭厂216组竹片炭的含水率、密度、灰分、挥发分、固定炭含量、燃烧热值、电阻率和pH值等理化性能进行测试.应用Matlab软件,采用概率密度分布方程、主分量分析和方差分析方法对竹炭的理化性能进行分析.结果表明:不同的竹炭生产厂家生产的竹炭理化性能差异极显著,而同一厂家生产的竹炭理化性能差异不显著;竹炭的理化性能相关性不紧密;挥发分和灰分与热值和pH值因子负荷量为异号,呈负相关;固定炭与热值和pH值因子负荷量为同号,呈正相关;灰分和密度与电阻因子负荷量为异号,呈负相关;灰分和密度与电导率因子负荷量为同号,呈正相关.     

Reduction of electric field strength by two species of trees under power transmission lines

Electrical pollution is a worldwide concern,because it is potentially harmful to human health.Trees not only play a significant role in moderating the climate,but also can be used as shields against electrical pollution.Shielding effects on the electric field strength under transmission lines by two tree species,Populus alba and Larix gmelinii,were examined in this study.The electrical resistivity at different heights of trees was measured using a PiCUS sonic tomograph,which can image the electrical impedance for trees.The electric field strength around the trees was measured with an elf field strength measurement system,HI-3604,and combined with tree resistivity to develop a model for calculating the electric field intensity around trees using the finite element method.In addition,the feasibility of the finite element method was confirmed by comparing the calculated results and experimental data.The results showed that the trees did reduce the electric field strength.The electric field intensity was reduced by 95.6%,and P.alba was better than L.gmelinii at shielding.     

Complex resistivity tomography (CRT) for fungus detection on standing oak trees

Complex resistivity tomography is presented as an extension of electrical impedance tomography for non-destructive structural tree investigation. Results of laboratory measurements with different frequencies suggest measuring the resistivity and in addition the phase shift at about 0.1 Hz. The measured data are processed using a finite-element-based inversion algorithm, which uses triangular meshes and is thus able to consider any tree shape. We apply the technique to three different oak trees with the aim of fungi detection. Measurements of a healthy tree both in summer and in winter show a ring-shaped structure and indicate a strong seasonal dependence, particularly for the resistivity magnitude. Tomograms on fungi-infected trees clearly show disturbances at the infections at different heights compared with healthy trees. A comparison with tree section photographs shows promising agreement. Moreover, a comparison with measurements at oak-wood samples in the laboratory shows at least partly quantitative coincidence. To conclude, the phase image provides additional information and helps to differentiate disturbances in the cell structure from pure moisture changes. Therefore, the method has the potential to deliver useful additional information, when carried out during routine tree assessment.     

Nondestructive detection of decay in living trees

We used a four-point resistivity method to detect wood decay in living trees. A low-frequency alternating current was applied to the stem and the induced voltage measured between two points along the stem. The effective resistivity of the stem was estimated based on stem cross-sectional area. A comparison within a group of trees showed that trees with butt rot had an effective resistivity that was at least a factor of two lower than that of healthy trees. In tests on several groups of Norway spruce (Picea abies (L.) Karst.) comprising more than 300 trees in total, the method detected butt rot with high accuracy. We validated the method both by measurements and by finite element modeling and simulations.     

刨花板抗静电性能的研究

通过全电流充放电法，测得在刨花施胶过程中施加不同种类和数量的抗静电添加剂时，刨花板体积电阻率呈下降趋势，并借此讨论了刨花板的抗静电机理，分析了抗静电性能。研究结果表明：抗静电剂ＳＮ与石墨或甘油共同作为抗静电添加剂时，刨花板体积电阻率下降明显。与普通刨花板相比，电阻率下降了二个数量级。此外，刨花板的含水率和密度，对其抗静电性能也有较大影响。     

An approach to GIS-based multiple criteria decision analysis that integrates exploration and evaluation phases: Case study in a forest-dominated landscape

The increasing importance and complexity of land and natural resource management are creating a need for ecosystem-based management (EBM). Multiple criteria decision analysis (MCDA) combined with geographic information systems (GIS) can integrate factors related to the triple bottom line of ecological, economic, and social perspectives required by EBM. However, GIS-based MCDA is limited in this role because (i) it rarely integrates or encourages an exploration phase in preparation for structured evaluation and (ii) inexperienced users may find MCDA methods and GIS software difficult to use. This paper presents a novel approach for (i) supporting an exploration phase to help structure a problem and (ii) integrating the exploration and evaluation phases in an easy-to-use software system. The approach was validated through a land-management case study in a forest-dominated landscape with a variety of stakeholders. Case-study participants used the approach to rate areas within a timber harvest plan based on their potential for conflict with conservation values. The case-study decision analysis determined that between 1.3% and 6.6% of the harvest plan area had a conservation rating of 0.30 or higher on a scale of 0–1. The system was made available to the forest industry and other stakeholders to support harvest plan adjustments, demonstrating how such tools can be used to improve and integrate our knowledge of forest ecology and management. Assessment of participant feedback reveals that an exploration phase is effective in helping understand a problem and prepare for multiple criteria evaluation (MCE).