共查询到20条相似文献，搜索用时 546 毫秒
1.
WANG Xiang CHEN Jianping XU Yanbo ZHENG Yongchun YAN Bokun WU Yunzhao 《《地质学报》英文版》2015,89(6):1882-1894
Spectra are sensitive in detecting main minerals on the lunar surface from visible light to infrared light. Since spectral characteristics of minerals are closely related to their compositions and the maturity level of soil on the Moon, studying the compositions and distribution of elements and minerals on the lunar surface can help to understand the evolution of the Moon through remote sensing technology. The correlation between the spectral characteristics of Chang’e-1 interference imaging spectrometry (IIM) reflectance images and the mineral contents of LSCC (Lunar Soil Characterization Consortium) lunar surface mineral samples was discussed and the spatial distributions of FeO and Al2O3 contained in both pyroxene and plagioclase on LQ-4 were studied using the improved angle parameter method, MNF, and band ratio statistics. A comparison of the mapping results of the optical models by Lucey, Shkuractov and other researchers on Clementine and the gamma ray spectrometry data shows that the content error is within 0.6% for lunar mare areas and close to 1% for the highland areas. The tectonic framework on the lunar surface was also investigated. And based on integrated analysis of previous findings on topography of the lunar surface, Chang’e LAM, CCD and LOLA images and the gravity anomalies data (Clementine GLGM-2), the tectonic unit subdivision was established for LQ-4, the idea of subdividing the lunar tectonic units was proposed, and this will provide a good foundation for studying the lunar tectonic evolution. 相似文献
2.
WANG Gang QIN Yong XIE Yiwei WANG Ziwei WANG Boyang WANG Qi ZHANG Xiaoyang 《《地质学报》英文版》2020,94(2):444-455
Multiple coal seams and interbedded rock assemblages formed in vertical progression due to the influence of multiple stages of sea level transgressions.Based on mercury injection experiment,low temperature liquid nitrogen experiment,porosity and permeability experiment and breakthrough pressure experiment,the vertical variation characteristics of coal-bearing strata in Gujiao block are explained in detail.The results of the mercury injection and low temperature liquid nitrogen experiments show that the pore structure characteristics fluctuate with increasing depth in the strata,with fewer micropores followed by transition pores.The BET specific surface area and average pore diameter of the Shanxi Formation are generally larger than those of the Taiyuan Formation.Due to the continuous cyclic sequence stratigraphy changes,the porosity,permeability,breakthrough pressure and breakthrough time of the samples show a certain cyclicity.Within the same sequence,the porosity is larger,and the permeability is smaller near the maximum flooding surface.Although the permeability of the sandstone samples is higher,the porosity is lower,and the breakthrough pressure and breakthrough times are greater.The strata in the study area formed in an oxidized environment that was affected by freshwater,and the pore structure of different lithologies is quite different.After the formation of sandstone,the intergranular pores generally underwent filling with secondary quartz,clay minerals and organic matter,resulting in low porosity and permeability. 相似文献
3.
Based on the principles of physical, optics, the author has derived a formula for the calculation of the angle of rotation D, when transmitted polarized light passes through a dielectric. The theory of transmitted rotation of glass reflector is, too, discussed in the paper. It has been shown that for linear polarized light normal to the plane of incidence, the original angle of rotation will inerease and for that parallel to the plane of incidence the decrease of the original angle of rotation will be expected. With the formula derived, calculations are made for certain cases. The trial-measurements of angles of.transmitted rotation by the coated glassreflector of some ore microscopes have been carried Out and the results indicate that the theoretical calculations are well coincident with the practical measurements. Finally, a new way is suggested for the application of transmitted rotation. 相似文献
4.
Based on the geological conditions and characteristics of mineralization present, three-dimensional geological modelling is used in conjunction with previous deep research results, in order to discuss the process of deep mineralization in the Tongling ore district. The structural analysis shows that surface deformation is strong, deep deformation is weak, the surface has mainly experienced brittle deformation, with the possibility of a large number of deep ductile deformations. There is a thrust nappe between the Tongling uplift and the Nanling basin, that is the boundary of the Tongling block, which has resulted in the southwest uplift of the Tongling block. Combined with the deep exploration data, the three-dimensional shape of the main rock masses is interpreted, with three-layer structures in the deep magma chamber. The spatial distribution of magmatic rocks is mainly controlled by the structure. The movement of magmatic hydrothermal fluid is dominated by mesoscale seepage in the deep part and ‘dike’ type upwelling in the shallow part. There is a certain coupling relationship between the ore-forming rock mass and the surrounding rock. The ore-forming age is dominated by the Yanshanian period. Based on the distribution, types and metallogenic characteristics of the deposits, the metallogenic model of ‘layer coupling’ in the Tongling ore district is summarized, with the ‘one body, two belts and a multilayer metallogenic system’ is established, which is significant for the future direction of deep prospecting in the Tongling area. 相似文献
5.
《地学前缘(英文版)》2018,9(6):1639-1648
Cohesion(c) and friction angle(φ) of rock are important parameters required for reliability analysis of rock slope stability. There is correlation between c and φ which affects results of reliability analysis of rock slope stability. However, the characterization of joint probability distribution of c and φ through which their correlation can be estimated requires a large amount of rock property data, which are often not available for most rock engineering projects. As a result, the correlation between c and φ is often ignored or simply assumed during reliability studies, which may lead to bias estimation of failure probability. In probabilistic rock slope stability analysis, the influence of ignoring or simply assuming the correlation of the rock strength parameters(i.e., c and φ) on the reliability of rock slopes has not been fully investigated. In this study, a Bayesian approach is developed to characterize the correlation between c and φ, and an expanded reliability-based design(RBD) approach is developed to assess the influence of correlation between c and φ on reliability of a rock slope. The Bayesian approach characterizes the sitespecific joint probability distribution of c and φ, and quantifies the correlation between c and φ using available limited data pairs of c and φ from a rock project. The expanded RBD approach uses the joint probability distribution of c and φ obtained through the Bayesian approach as inputs, to determine the reliability of a rock slope. The approach gives insight into the propagation of the correlation between c and φ through their joint probability into the reliability analysis, and their influence on the calculated reliability of the rock slope. The approaches may be applied in practice with little additional effort from a conventional analysis. The proposed approaches are illustrated using real c and φ data pairs obtained from laboratory tests of fractured rock at Forsmark, Sweden. 相似文献
6.
The paper deals with the relatively weak permeable layer in a layered structure of a slope rock mass and itseffect on groundwater behaviour in the rock mass. When the whole groundwater table is declined in such typeof slope rock mass, the permeability of the relatively weak permeable layer in the middle will be several timeslower than that of the upper and lower permeable layers and consequently the water level in layers of differentpermeability will fall in different rates which will lead to a discontinuous phenomenon of the water body. Amethod of finite element simulation on a vertical two-dimensional profile is suggested for the study of the phe-nomenon and its application to practical situation is described. The calculation result shows that the existingweak permeable layer in a layered slope rock mass exerts unnegligible influence on the variation of water levelin the rock mass of a slope. The result also proves the applicability of the finite element simulation method. 相似文献
7.
The structural coupling is a common geological phenomenon. The structural differences between eastern and western active continental margins of modern Pacific and between paleo-Pacific and modern-Pacific continental margins are related to the characteristics and status of the subducting oceanic plate, namely, 1. subducting angle; 2. change in subducting angle; 3. subducting velocity; 4. change in subducting velocity; 5. subduction depth; 6. horizontal distance between the leading edge of the subducting plate and the trench; 7. the structural form of the subducting plate at the 670kin boundary between the upper and lower mantle; 8. the displacement and the direction of displacement of subducting plate. The control and influence toward the shallow-level structures by the deep-level structural activities is a detailed representation of the structural coupling on active continental margin. The basin-maintain coupling phenomenon is an intracontinental structural coupling. The far field effect of collision be 相似文献
8.
Frozen soil is generally regarded as a strongly rheological geomaterial. The strength attenuation of frozen soil is an important inducement for disease and instability in subgrade engineering, pile engineering and artificial freezing construction. Few efforts have been made to investigate the attenuation characteristics of strength envelope surface for frozen soil under complex stress states experimentally and theoretically. Considering this, at a temperature of -6 ℃, a series of triaxial stress relaxation tests under various confining pressures were carried out on the frozen subgrade soil specimens at strength points. The degeneration of strength parameters and stress attenuation process of frozen soil under complex stress states were systematically studied. The degradation law and mechanism of cohesion and internal friction angle are synchronously revealed in the stress relaxation process. Testing results indicate that the stress relaxation process of compacted frozen soil is significantly influenced by confining pressure. The stress relaxation ratio is increasing linearly with the rise of confining pressure if the confining pressure is beyond 1. 5 MPa. The anti-relaxation ability of frozen soil is greatly reduced during high confining pressure conditions:the stress relaxation ratio of frozen soil is only 41. 94% under 1. 5 MPa, but exceeds 90. 30% under 16 MPa. The strength of frozen soil attenuates linearly with time in the semi-logarithmic coordinate system. When the confining pressure is higher than 1. 5 MPa, the strength attenuation rate of frozen soil increases with the rise of confining pressure. As the development of stress relaxation of frozen soil, cohesion decreases linearly but internal friction angle increases linearly with time in the semi-logarithmic coordinate system. It manifested that the cementation in frozen soil shows evident rheological features and it is a key inducement for strength attenuation. Moreover, the attenuation law and value of cohesion in frozen soil which is measured by triaxial stress relaxation test are similar to the spherical template indenter test results. This may provide a new test method for obtaining the long-term strength and cohesion of frozen soil. On the basis of test results, the stress states of frozen soil in all stress relaxation curves at 12 relaxation durations were captured, and the rate-dependent variation characteristics of strength envelope in p-q stress space were analyzed in detail. Under high confining pressures, the strength envelope of frozen soil shows different geometric features as time goes on. In addition to the decline of level, the strength surface exhibits clockwise rotation with time, and the third stage sharply decreases at first and then becomes flat. Based on the analysis of characteristics of experimental strength surface and evolution law of strength parameters during the stress relaxation process, a rate-dependent strength theory for frozen soil considering the stress relaxation effect is established in this paper. © 2022 Science Press (China). All rights reserved. 相似文献
9.
The Yaojialing deposit is the first large-scale Zn–Au–Cu polymetallic skarn deposit located in the Shatanjiao ore field of the Tongling area in the Middle–Lower Yangtze belt. It has distinct metallogenic characteristics and is clearly different from the known skarn Cu–Au deposits in the Tongling area and the Middle–Lower Yangtze belt. Previous studies of the Yaojialing deposit have included rock geochemistry, alteration and mineralization characteristics, as well as metallogenesis and metallogenic models. However, there are still numerous problems concerning the coexistence of multiple elements, metallogenetic specialization of the magma and the metallogenic model. In this study, using the latest production exploration work on the deposit, we investigated the Yaojialing deposit including its geological characteristics, petrography, LA–ICP MS zircon U–Pb dating and whole rock geochemistry. Two kinds of magmatic rocks have been distinguished for the first time in the deposit, amongst which the granodiorite porphyry exposed on the surface of the mining area, which is the host rock of the veined lead–zinc ore body, is the wall-rock intrusion; and the deep concealed quartz monzonite porphyry is the causative intrusion, the distribution of orebodies and wall-rock alteration characteristics showing regular zoning around the quartz monzonite porphyry. The 206Pb/238U weighted average age of the granodiorite porphyry is 140.2 ± 1.0 Ma (MSWD = 0.85, n = 13) by LA–ICP MS zircon U–Pb dating, while the quartz monzonite porphyry is 138.9 ± 1.2 Ma (MSWD = 0.60, n = 16), which is consistent with petrographic evidence. The geochemical characteristics show that the quartz monzonite porphyry is a high-K calc-alkaline series peraluminous rock. The trace element characteristics show that the quartz monzonite porphyry is enriched in LILE such as K, Rb, Sr, Ba and LREE, yet depleted in HFSE such as Nb, Ta, P and Ti. The Yaojialing deposit shows the mineralization characteristics of proximal skarn and distal skarn, having the common characteristics of ‘multi-storey’ and ‘Trinity’ metallogenic models. 相似文献
10.
The Yanchangbeishan biotite adamellite in the Lenghu area of Qinghai is located in the west segment of the north margin of Qaidam. The rocks have high SiO2 (73.92%-75.98%) and K2O contents (3.71%-4.78%), but low MgO and CaO contents. The alumina saturation index (A/CNK) varies from 1.03 to 1.11, indicating the biotite adamellite is peraluminous. The chondrite-normalized REE patterns of the rocks are right dipping and display weak Eu anomalies. The rock contains the Al-rich mineral like garnet and possesses normative corundum contents of 1%. It has low Th and Y contents which are negatively correlated with Rb, suggesting the source rock was sedimentary rock. Thus, the biotite adamellite belongs to S-type granite. The granite was produced by partial melting of the crust material due to the underplating of mantle-derived magma. LA-ICP-MS zircon U-Pb dating shows that the formation age of the rock is 254±4 Ma. Based on the regional geological background and the geochemical characteristics of the rocks, we consider that the formation of the Yanchangbeishan biotite adamellite was related to subduction, which is illustrated by the characteristics similar to those of the island-arc igneous rocks. Therefore, the results reveal that the north margin of Qaidam was in active continental margin tectonic environment during Late Permian epoch. ©, 2015, Science Press. All right reserved. 相似文献
11.
水面的镜面反射是影响水环境遥感的关键因素之一。通过分析气-水界面反射光的偏振特性,从多角度偏振遥感的角度,提出一种剥离水面反射光的方法,并通过室内实验进行了验证。将ASD光谱仪与线偏振片结合扩展成高光谱偏振传感器,获取不同观测天顶角时水面反射光的偏振光谱。结果表明,当探测角不满足布儒斯特角时,在偏振片的主消光方向能剥离绝大部分的水面反射光;当入射角越接近布儒斯特角,其剥离效果越佳;以布儒斯特角观测时,可以达到完全剥离的效果。即该方法能显著削弱、甚至完全剥离水面的反射光,直接获取离水辐亮度,对于提高水色遥感的精度有着重要的应用价值。 相似文献
12.
频谱激电法若干理论研究 总被引：6，自引：0，他引：6
本文讨论了频谱激电效应的传递函数模型,提出了一个面极化体极化系数的数学表达式,并依此给出地下半空间中球体上复电阻率的计算公式和计算结果,得到了复电阻率谱随某些控制因素变化的一些规律. 相似文献
13.
不同岩石矿物和矿化蚀变具有不同的光谱特征, 这是利用遥感技术进行岩石矿物和蚀变信息识别的基础。本研究在谢米斯台地区进行岩矿样品采集, 利用ASD野外光谱辐射仪采集光谱反射率数据, 通过去噪处理、标准化处理、微分处理和去包络线处理, 开展了典型岩矿样品、风化面与新鲜面样品和不同矿化蚀变的光谱特征提取和光谱分析。研究发现, 岩矿在380~1 100 nm波段的光谱特征, 主要是金属离子产生;在1 100~2 500 nm波段的光谱特征, 主要是阴离子基团中的羟基、碳酸根和水分子产生;矿化蚀变光谱具有可诊断性特征谱带, 是其矿物组成中的各种蚀变矿物特征信息的反映;受到矿物含量改变和外界环境因素的影响, 光谱的整体形态或局部特征都发生变化。岩矿光谱特征的提取和分析, 将提高和改善高光谱技术对不同区域同种类型的矿床勘查。 相似文献
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15.
为了研究节理对锚固岩体力学特征和失稳损伤演化的影响,采用对锚固贯通节理岩体进行室内剪切试验和PFC2D数值模拟的方法,研究不同节理倾角下锚固贯通节理岩体剪切性能的作用机制和破坏模式,研究结果表明:（1）随着节理倾角变化,贯通节理岩体呈现出不同的破坏形式,锚固贯通节理岩体的抗剪强度与剪切位移曲线并不是呈线性增长,而是呈"双驼峰"趋势。（2）锚固体系在剪切试验的过程中,节理面颗粒的接触方位角会发生一定程度的改变,主要集中在锚杆和节理倾角附近。（3）锚固体系在剪切试验的过程中,会因为颗粒间黏结键的断裂生成裂纹,裂纹数生成的越少,其抗剪强度越高,裂纹分为张拉裂纹和剪切裂纹,并且张拉裂纹的数量要远远大于剪切裂纹的数量。研究结论可用于实际工程破坏模式的预测和岩体工程稳定性评价。 相似文献
16.
We calculated theoretical acceleration response spectra at the ground surface in the region near the 1995 Hyogo-ken Nambu earthquake source based on the spectral moment method. To estimate earthquake motion on the ground surface, a formula of earthquake motion at base rock level was derived. The amplification effect of the ground was introduced by using multiple reflection theory. Theoretically estimated response spectrum were modified by the response spectra calculated using observed earthquake motions. 相似文献
17.
地表风化产生的表面覆盖层、风吹送的尘埃、胶结物或附着物在岩矿表面形成的外壳是影响地表高光谱遥感识别和反演的重要和关键因素。本研究区位于干旱缺水的新疆西准噶尔包古图地区,对岩矿表面的风化面、胶结物形成的荒漠漆、附着于岩面的地衣和原岩的新鲜面进行了波谱测定分析、X射线荧光元素分析和光薄片镜下观察。结果表明：该地区的大部分岩石表面有风化层覆盖,主要为物理风化,少部分岩石表面发生了化学风化;荒漠漆波谱在可见光波段改变原岩本身的波谱形态,但在短波红外波段,保持原岩波谱特征只改变了反射率大小,并不影响对原岩矿物质的高光谱探测;地衣附着于岩表的波谱特征不仅改变了波谱反射率,还完全改变了原岩的波谱形态,对原岩表面波谱有混淆干扰作用。岩矿表面的研究是波谱测量从实验室走向野外实际应用的基础,也是利用高光谱遥感技术直接进行矿物识别、相似矿物的区分以及提取矿物含量和化学成分研究的最初和关键一步。 相似文献
18.
文章分析了探地雷达与电磁场的入射和散射相关的散射矩阵S的性质,散射矩阵中的四个元素提供了入射波场不同极化方向对应的信息,基于此,利用散射矩阵S的Alford旋转,估算细长目标体的方位角。由于低振幅和噪声等缘故,实际上角度的估算是一个不稳定的过程,因此,选择使用范数作为筛选最佳振幅的工具,使角度的估算更加准确和稳定。利用埋在均匀半空间内的金属管的三维模型所得到的模拟数据,对该方法进行了测试,在选择合适的振幅时,确定Frobenius范数‖S‖F≥0.1·‖S‖F(max)的标准,结果表明,估算地下管线方位角的方法是有效的。 相似文献
19.
目前,场地影响评价方法可以分为理论法和经验法。地脉动水平分量与竖向分量谱比法属经验法。这种方法将地脉动水平分量与竖向分量谱比的最大值对应的频率和幅值分别看作是观测场地的卓越频率和放大因子。虽然该法在国内外很多工程实例中得到了理想的结果。但由于这种方法建立过程中应用了许多假设,所以很多地震工程学家对这种方法持怀疑态度。本文讨论了基岩地脉动水平分量与竖向分量谱比为1这一假定的合理性。并采用泊松弹性半空间模型,应用概率分析方法考虑地脉动的随机性,推导了地下体波斜入射弹性半空间自由表面形成地脉动的水平分量与竖向分量谱比表达式。通过计算论证体波斜入射泊松弹性半空间形成的地脉动水平分量与竖向分量谱比特性。结果表明：当地脉动主要成分为体波时,基岩表面地脉动水平分量与竖向分量谱比接近于1;当地脉动主要成分为面波时,基岩表面地脉动水平分量与竖向分量谱比介于0.54～0.79之间。对泊松基岩,该比值是0.68。 相似文献
20.
高精度连续测斜仪探管的原理及应用 总被引：1，自引：0，他引：1
北京中地英捷物探仪器研究所新研制的PSX-2高精度连续孔斜检测探管,采用三轴正交磁性传感器和两个正交加速度计传感器测量,其中加速度计传感器测量顶角,磁性传感器测量方位角,实时测量的信息及解算则依靠内部集成的24位模数转换单片机来完成。实地测井证明,PSX-2型孔斜检测探管可以在顶角较小时稳定的测量方位角,符合煤田测井行业对钻孔测斜仪提出的高精度、小体积、低成本的要求。 相似文献