共查询到20条相似文献，搜索用时 171 毫秒
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基于二连盆地满都拉图地区的宽频大地电磁(BMT)数据,开展了精细反演处理研究,旨在提高数据的反演精度与效果,为其他地区BMT数据的精细反演处理提供示范与借鉴。通过研究区BMT数据精细反演处理研究,选择OCCAM反演方法与TM+TE数据模式,反演参数选择背景模型为二维移动平均电阻率模型、正则因子为0.4、第一层厚度为40 m时,有效提升了数据的反演准确度,为后续资料的精细解释奠定了基础。研究结果表明：利用已知钻孔或地震资料等先验信息,首先开展有针对性的反演方法、反演数据模式以及反演参数等适用性试验研究,是确保资料减少多解性、获得可靠反演精度与效果的关键。 相似文献
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大地电磁测深资料常规反演方法的应用现状及进展 总被引：1，自引：0，他引：1
文中介绍了大地电磁测深(MT)资料处理解释中几种常规地球物理反演方法的基本原理及该领域内的最新进展,通过应用实例分析说明在进行资料定量解释的过程中应该多种反演手段相互佐证.可以用BOSTICK反演结果建立初始模型,通过一维、二维反演,在结合地质、物探资料并通过正演模拟计算验证的基础上,建立合理的地质-地球物理模型.利用综合信息建模及反演成像技术结合现代地质理论,能有效地降低解的非唯一性,提高解释结果的可靠程度及综合地质解释结果的合理性. 相似文献
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左海燕 《物探化探计算技术》1983,(4)
一、前言近年来,由于电子计算技术广泛应用,在物探资料推断解释中引入了一些最优化算法。有关这些算法的基本理论及其在地球物理反演问题中具体应用己有较详尽的论述。但是,一般的无约束最优化算法无论在模型实验还是实际资料处理中都存在多解性,这往往会影响反演结果的可靠程度。因此,最近几年地球物理反演理论己逐渐集中于研究约束条件下的最优解问题。例如Safon、Vasseur以及Cuer(1977)提出利用线性规划方法,在有各种 相似文献
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井震联合地震道多尺度反演 总被引：3，自引：0，他引：3
多尺度（多分辨率）反演是近几年才提出的一种加快收敛速度，克服局部极小值影响，搜索全局最小极值点的反演策略，将垂向上分辨率较高的测井资料和横向上连续性较好的地震资料在地质理论指导下进行联合地震道反演，同时将小波变换多尺度分析（多分辨率分析）思想应用于上述反演中，实现对地震道多尺度（多分辨率）反演，理论和实际资料的处理均表明，这种反演方法具有收敛速度快，反演精度较高，适应能力较强的特点。 相似文献
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本文采用非线性反演技术建立了岩性约束反演计算方法，用于地层岩性解释和储层模拟、描述等方面。文中讨论了岩性正演数学模型的建立、初始模型的选取和约束条件对反演结果的影响。给出了综合利用地震、测井和地质资料计算孔隙度和泥质含量的反演结果，并分析了反演精度。理论模型计算结果说明了岩性约束反演的可行性和正确性。并给出Ｓｕｎ工作站上应用该软件处理某油田实际资料的岩性反演结果。 相似文献
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吴宣志 《物探化探计算技术》1984,(2)
本文讨论利用重力资料反演莫霍面时,地壳横向不均一性,密度随深度变化以及异常数据滑动平均处理对解释结果的影响程度。理论横型和实测资料分析表明,这些因素是不可忽视的。文中讨论了窗口滑动平均的物理意义和滤波作用。最后介绍了变密度体重力异常反演的技术,提出了进一步解释工作方案的建议。 相似文献
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大陆岩石圈导电性的研究方法 总被引：17，自引：2，他引：17
随着地球科学的进展 ,大陆岩石圈导电性结构的研究越来越引起人们的重视 ,而超宽频带大地电磁测深则是目前用于探测岩石圈导电性最有效的地球物理先进技术。它把现代性能优良的宽频带大地电磁系统 (MT 2 4NS或V5 2 0 0 0 )与长周期智能化大地电磁系统 (LIMS)配套使用 ,采集地面上频率范围为n× 10 -4～n× 10 2 Hz的天然电磁场信号 ,并通过一系列数据处理和反演计算 ,获得深达下地壳和上地幔的地下导电性结构模型。此模型不仅可以提供有关岩石圈地质构造轮廓的信息 ,更重要的是可以间接反映现今地下深部的热结构特征和物质状态分布特点。多年来 ,应用超宽频带大地电磁测深对青藏高原岩石圈导电性结构的研究表明 ,高原的中、下地壳确实是良导电性的 ;它可能说明西藏地壳中普遍存在岩石的局部熔融 ,或地热流体。沿着应县—商河剖面的大地电磁测深研究结果从电性的角度证明了太行山山前断裂为一组向东倾斜的深断裂 ,华北地区岩石圈以其为界划分为东、西两区 ;东区为低阻区 ,与构造活动区的岩石圈导电性特征相符 ;西区为高阻区 ,表现出稳定大陆区岩石圈导电性结构的特点。 相似文献
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We present the results of JHKLM photometry of the oxygen Mira variable V2108 Oph acquired in 2000–2004. The period of brightness variations is refined (570
± 3 days), and light and color curves in the near-IR are presented. The mean fluxes, color temperatures, and sizes for two
blackbodies representing the combined radiation of the star and dust shell at minimum and maximum brightness are estimated.
Additional IRAS data were used to compute a model with a spherically symmetric dust shell of silicate grains; the best-fit
model has a radius for its inner boundary of 2.4 × 1014 cm, a dust temperature at this boundary of 1150 K, an optical depth of the shell at 0.55 μm of 16.8, and implies a distance
to the star of 980 pc. We estimate the mass-loss rate for V2108 Oph to be 1.2 × 10−5
M
⊙/yr.
Original Russian Text ? M.B. Bogdanov, O.G. Taranova, V.I. Shenavrin, 2006, published in Astronomicheskiĭ Zhurnal, 2006, Vol.
83, No. 5, pp. 437–442. 相似文献
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Distribution of heavy metals in soils of Port Harcourt and its environs,Niger Delta,Nigeria 总被引：1，自引：0，他引：1
Geochemical evaluation of the distribution of heavy metals in soils of Port Harcourt and its environs in the Niger Delta region is presented in respect of anthropogenic factor and index of geoaccumulation. Sixteen (16) soil samples were collected from two horizons (0-10 cm and 100 cm) from the various grids and analyzed. The geo-chemical analyses showed the vertical and horizontal distributions of heavy metals. The results showed the ranges of the metals determined as follows: Pb (6.86-2.49)×10-6, with an average of 4.63×10-6; Cd (0.05-0.00)×10-6, with an average of 0.02×10-6, As (0.01-0.00)×10-6, with an average of 0.00×10-6. Cu (15.36-10.80) ×10-6, with an average of 13.36×10-6, and V (1.36-0.20)×10-6, with an average of 0.94×10-6. Quantification of the degree of pollution was carried out using anthropogenic factor (AF) and index of geoaccumulation (Igeo). The Igeo values of 0.06, 0.02 and 0.00 for Pb, Cd and As, respectively indicate low-level contamination while Zn (1.14) and V (1.40) show me-dium-level contamination. The sources of contamination are attributed to urbanized anthropogenic activities. The majority of the samples analyzed show that the AF values are less than 1 with the exception of vanadium (V) whose AF values range from 2.73 to 13.60×10-6. Vanadium is more enriched than As, Cd, Pb, and Cu. The order of degrees of anthropogenic contamination and index of geoaccumulation in the soil is V >Zn >Pb >Cu >Cd >AS. Metals were retained near the top soil and their concentrations in the deepest horizons were lower and normal for uncontaminated soils. Metal concentrations in the top soil horizons were significantly related to distance from the industrial and hu-man activities. 相似文献
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T. N. Tarasova 《Astronomy Reports》2014,58(5):302-318
Spectrophotometric observations are used to study the envelopes of the FeII nova V2467 Cyg and the HeN nova V2491 Cyg. The abundances of several elements in the nova envelopes and the envelope masses are estimated. The nitrogen mass abundance in the V2467 Cyg envelope is higher than the solar value by a factor of 186 and the oxygen abundance by the factor of 10. The nitrogen abundance in the envelope of V2491 Cyg exceeds the solar value by a factor of 56, the oxygen abundance by a factor of 12, and the neon abundance by a factor of 8. The masses of the envelopes were estimated to be 8.5×10?5 M ⊙ for V2467 Cyg and 1.5×10?5 M ⊙ for V2491 Cyg. These envelope elemental abundances and masses are in good agreement with those of low-mass CO white dwarfs (0.8 M ⊙) and ONe white dwarfs (1.15 M ⊙). 相似文献
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Electrical Structures of the Crust and Upper Mantle of Tibetan Plateau From Magnetotelluric Profiling of Indepth-Mt 总被引：1，自引：0，他引：1
Wei Wenbo Tan Handong Jin Sheng Deng Ming Martyn Unsworth Shenghui Li Paul Bedroson John Booker Alan Jones WT ”BX 《地学前缘》2000,(Z1)
ELECTRICAL STRUCTURES OF THE CRUST AND UPPER MANTLE OF TIBETAN PLATEAU FROM MAGNETOTELLURIC PROFILING OF INDEPTH-MT 相似文献
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为研究宿州地区寒武系豹皮灰岩地球化学特征及其地质意义,对研究区岩石进行了系统鉴定,并对其主量元素和微量元素进行了地球化学测试。结果显示:寒武系豹皮灰Ti含量、Er/Nd、Y/Ho值均偏低,反应其形成过程中受到陆源碎屑的影响。元素具有明显的U、Pb、Sr、Sm富集及Ba、Nb、Ce、Pr、Zr亏损,稀土总量为3.07×10~(-6)~7.00×10~(-6)(平均为5.33×10~(-6)),低于典型海相灰岩值。V含量较低,V/Cr比值在1.02~1.73之间,说明豹皮灰岩形成于氧化环境;Sr/Ba异常值较高,反映了高度咸化条件下的海相沉积;Sr/Cu值暗示了干旱的气候条件。综合前述认识,研究区豹皮灰岩应形成于局限碳酸盐岩台地环境。 相似文献
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The host rocks of the porphyry tin deposits in the Yangbin area are principally topaz-bearing porphyry dikes about 2 km long and 2–20m wide. Three lithologie types are identified for the dikes: topaz-bearing potassium feldspar granitic porphyry, topaz-bearing monzonitic granitic porphyry and topaz-bearing quartz porphyry. The content of topaz in the rocks ranges from 10 to 20 vol.%. Porphyritic texture is characteristic, with quartz, potassium feldspar and albite as main phenocryst minerals. The phenocryst occupies 10–20 vol% of the rocks. The rock groundmass consists of subhedral topaz, quartz and protolithionite. Topaz has a unit-cell parameter b=8.797 (Å), and F:OH=1.92:0.18, indicating a F-rich variety formed at high temperature. The topaz-bearing porphyries occurring in this area are strongly peraluminous (A/NKC=1.574–12.94), with high ratios of F/Cl (146–303) and Rb/Sr (5–122). They are rich in incompatible elements (Sn, 313 × 10?6–1042 × 10?6; W, 6 × 10?6–218 × 10?6; Nb, 27 × 10?6–54 × 10?6), but poor in compatible elements (Sr, 10 × 10?6–28 × 10?6; Ba, 58 × 10?6–73 × 10?6; V, 3 × 10?6–12 × 10?6, Cl, 150 × 10?6–226 × 10?6). The rocks are also characterized by high total REE amount (281.69 × 10?6–319.76 × 10?6), with strong Eu depletion (δEu=0.01–0.03) and low ratio of LREE/HREE (0.78–0.84). In summary, the authors propose an idea of S-type genesis for the topaz-bearing porphyries with tin mineralization, instead of I-type. 相似文献
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《Geodinamica Acta》2013,26(5):301-321
The Pressure-Temperature-time paths of metapelites sampled on an east-west transect across the structural dome of Naxos (Greece) have been reconstructed on the basis of new geothermobarometric data and Rb/Sr dating, as well as previously published data. One sample from an intermediate structural level records pressure and temperature conditions of 10 kbar, 500°C, corresponding to its exhumation in a highpressure/low-temperature (HP/LT) setting. The corresponding Rb/Sr exhumation age is 29.3±1.3(2s) Ma. Toward the center of the dome, metamorphic assemblages record an increase in peak-temperature and corresponding pressure (from 500 to 700°C, and from 5 to 8 kbar), in a medium-pressure/medium-temperature (MP/MT) metamorphic field gradient. Whole-rock, muscovite and biotite on two samples from deep structural levels define ages of 5.2 and 7.0 Ma, whereas garnets fall outside the isochrons and retain earlier less radiogenic signatures. Rb/Sr data on these two samples demonstrate open system behaviour coeval with, or subsequent to MP/MT metamorphism. The interpretation of the Pressure-Temperature-time paths indicates a time span of 15-20 Ma for dome formation. It also suggests that the HP/LT to MP/MT transition is due to i) heating of deeper parts of the dome through magma injection or ii) either homogeneous (75 %) or localized thinning during dome formation. 相似文献
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The abundances of 29 elements, including nine REE (La, Ce, Nd, Sm, Eu, Tb, Dy, Yb and Lu), have been determined by instrumental neutron activation analysis in 33 tholeiitic basalts from Mauna Loa, Kohala, Mauna Kea, Lanai and Koolau. These data have been combined with data provided by A. V. Murali et al. on seven basalts from Kilauea for geochemical evaluation.Partial melting models based on the partitioning of the REE and Sc suggest that these basalts can be produced from three distinct source compositions. Thus, the basalts from Mauna Kea, Kohala and Kilauea are generated by 2–10% partial melting of similar source materials in the compositional range 82 ± 4% olivine plus orthopyroxene (ol + opx), 14 ± 3% clinopyroxene (cpx) and 4 ± 1% garnet (gar). Similar amounts of melting of source materials having 74 ± 6% ol + opx, 21 ± 5% cpx and 5 ± 1% gar produce the basalts of Mauna Loa and Lanai. A source material composed of 86 ± 4% ol + opx, 11 ± 2% cpx and 3 ± 1% gar is proposed for the generation of basalts from Koolau.The olivine-crystallization model suggested here requires absolute REE abundances in the preferred Mauna Kea, Kohala and Kilauea source to range from 1.1× (times chondrite) for the LREE (La) to about 1.3× for the HREE; in the Mauna Loa and Lanai source, La is about 1.0× and the HREE are about 1.6×; and in the Koolau source, La is ~0.7× and the HREE are ~0.9×. 相似文献
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V5-2000大地电磁测深仪由于其功能强、轻便、勘探范围大等特点,在国内已得到了广泛应用,但其后期数据解释软件却显得相对薄弱。要想解决解释软件的问题,首先所面临的是测量数据的格式问题。由于其保存的测量数据为特殊格式,为了便于对V5-2000测量数据进行后期处理与分析,这里对V5-2000测量数据的特殊数据格式进行了剖析,并用现今流行的,面向对象化的VB6.0编程语言,编写了相关读取及修改程序,以作为下一步的后期数据解释软件开发之基础。 相似文献