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Multifractal modelling and spectrum analysis: Methods and applications to gamma ray spectrometer data from southwestern nova Scotia, canada

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Science China earth sciences 2006年第3期49卷 283-294页

作者： CHEnG Qiuming1,2 1. State Key Lab of Geological processes and Mineral Resources, China university of Geosciences, Wuhan 430074, China 2. department of earth and Space Science and Engineering, department of Geography, York university, 4700 Keele Street, Toronto, ontario, M3J 1p3, canada 1. State Key Lab of Geological processes and Mineral Resources China University of Geosciences Wuhan 430074 China 2. department of earth and Space Science and Engineering Department of Geography York University 4700 Keele Street Toronto Ontario M3J 1P3 Canada

Multifractal spectrum, autocorrelation/semivariogram and power spectrum are three dif- ferent functions characterizing a field or measure from different aspects. These functions are interre- lated in such that the autocorrelation/semivariogram and power spectrum are related to the low order statistical moments (0 to 2 nd) which may determine the local multifractality (τ ″(1)) of a multifractal measure. A better understanding of the interrelationships among these three functions is important because, on one hand, the multifractal modelling characterizes a multifractal measure in a more de- tailed manner since it involves moments of all orders. On the other hand, the commonly used semivariogram and power spectrum functions can be used as alternatives to study the dominant mul- tifractal properties around the mean measure. Moreover, semivariogram and power-spectrum func- tions provide spatial and spectral information, which is highly valued in geological applications. A new fractal relation found between area and power-spectrum will be useful for investigation of new meth- ods of spatial-spectral analysis for pattern recognition, anomaly separation, classification, etc. These results have been demonstrated with the case study of modelling gamma ray spectrometer data from the mineral district, southwestern nova Scotia, canada. The results have shown that the values of uranium (U), thorium (Th) and potassium (K) may possess monofractal properties whereas the ratios of these values show high multifractality. The values of the ratios U/K and U/Th show relatively large variances and may provide more information for distinguishing the distinct phases of the granites, country rocks as well as possible gold mineralization-associated regional hydrothermal alteration zones. In addition, the power spectra for U, Th, K, U/Th and U/K consistently show two distinct power-law relationships for two ranges of wave number 12≤ω ≤160 km and 0≤ω ≤12 km. These properties might provide usefu

关键词： gamma ray spectrometer data, gold mineralization, alteration zones, multifractal modelling, spectral analysis, GIS.

InCIpIEnT MOTIOn OF nOn-COHESIVE SEDIMEnT UnDER ICE COVER-An EXpERIMEnTAL STUDY

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Journal of Hydrodynamics 2008年第1期20卷 117-124页

作者： WAnG Jun SUI Jue-yi KARnEY bryan W. School of Civil Engineering Hefei University of Technology Hefei 230009 China environmental Science and environmental Engineering program University of Northern British ColumbiaBritish Columbia Canada V2N 4Z9 department of Civil Engineering University of Toronto Toronto Ontario Canada M5S 1A4

based on a series of experiments under both ice-covered and free surface conditions, the present article discusses the role of flow velocity and critical shear Reynolds number for incipient motion of bed material. The influence of the resistance coefficients of both the underside of the ice cover and the channel bed on the location of the maximum velocity has been discussed. In addition, the impacts of ice and composite resistance coefficients on flow velocity for incipient motion of bed material have been assessed. The diagram describing the critical shear Reynolds number and the dimensionless shear stress for the incipient motion of sediment under ice covered conditions with different under cover resistance coefficient has been established. The effects of grain size on densimetric Froude number for incipient motion of bed material have been investigated. A relationship between the densimetric Froude number for incipient motion of bed material and the median grain size of bed material as well as the roughness coefficient of channel bed and roughness coefficient of ice cover has been established.

关键词： densimetric Froude number grain size ice cover incipient motion resistance coefficient shear Reynolds number,velocity

new stylophorans(Echinodermata) from the Upper Cambrian of Guangxi,South China

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Science China earth sciences 2008年第2期51卷 181-186页

作者： HAn naiRen1 & CHEn GuiYing1,2 1 department of Resources and environmental Engineering, Guilin university of Technology, Gulin 541004, China 2 Faculty of earth sciences, China university of Geoscience, Wuhan 430074, China department of Resources and environmental Engineering Guilin University of Technology Gulin 541004 China Faculty of earth sciences China University of Geoscience Wuhan 430074 China

This paper describes for the first time the cornute stylophorans (Echinodermata) in China. The new material came from the Guole Formation of the Furongian (Late Cambrian) in the Guole area of Jingxi, Guangxi province, South China. These new cornute specimens are preserved in situ and found along with well-preserved trilobites and brachiopods. One new species, phyllocystis jingxiensis sp. nov., is proposed to accommodate these unusual materials. The new species is defined by the small, heart-shaped theca with the frame composed of ten narrow, smooth and thick marginal plates, three adoral plates and distinctive zygal and aulacophore. both supracentrals and infracentrals are polygonal-outlined. The marginal plate M1' on the inferior face extends posteriorly to form zygal that possesses a broadened proximal end and the proximal portion joining with the conjunction between M4 and M5 on the inferior face. Aulacophore comprises ten segments at its proximal part and is conical at the middle part (named stylocone). Its distal portion is rather long and bears conspicuous ambulacrum grooves. Tectals are horizontally arranged on superior face and obliquely arranged on inferior face. both cothurnopore and anal pyramid are vaguely seen on the right anterior corner and the extremity of theca's superior face.

关键词： phyllocystis Stylophora Echinodermata Cambrian Guangxi South China

Effects of Topographic Slopes on Hydrological proecsses and Climate

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Advances in Atmospheric sciences 2001年第5期18卷 733-741页

作者： Jinliang Liu Climate processes and earth Observation Division, Meteorological Service of canada, 4905 Dufferin Street, Downsview, ontario M3H 5T4, canada Han-Ru Cho department of Atmospheric Science, national Central university, Chungli 320, Taiwan Climate processes and earth Observation Division Meteorological Service of canada Downsview canada national Central university Chungli Taiwan

based on previous research results on river re-distribution models, a modification on the effects of topographic slopes for a runoff parameterization was proposed and implemented to the nCAR's land sur- face model (LSM). This modification has two aspects firstly, the topographic slopes cause outflows from higher topography and inflows into the lower topography points; secondly, topographic slopes also cause decrease of infiltration at higher topography and increases of infiltration at lower topography. Then changes in infiltration result in changes in soil molsture, surface fluxes and then in surface temperature, and eventual- ly in the upper atmosphere and the climate. This mechanism is very clearly demonstrated in the point bud- gets analysis at the Andes Mountains vicinities. Analysis from a regional scale perspective in the Mackenzie GEWEX Study (MAGS) area, the focus of the ongoing Canadian GEWEX program, shows that the modi- fied runoff parameterization does bring significant changes in the regional surface climate More important- ly, detailed analysis from a global perspective shows many encouraging improvements introduced by the modified LSM over the original model in simulating basic atmospheric climate properties such as thermodynamic features (temperature and humidity). All of these improvements in the atmospheric climate simulation illustrate that the inclusion of topographic effects in the LSM can force the AGCM to produce a more realistic model climate.

关键词： Hydrological processes Runoff,parameterization Topographic slope Climate model Land surface model

Selection of Multifractal Scaling breaks andSeparation of Geochemical andGeophysical Anomaly

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Journal of China university of Geosciences 2001年第1期12卷 54-59页

作者： Cheng Qiuming department of earth and Atmospheric Science, department of Geography, York university, Toronto, ontario, canada, M3J 1p3 department of earth and Atmospheric Science Department of Geography York University Toronto Ontario Canada M3J 1P3

Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of functions within certain scale ranges The multifractalities can be estimated by applying multifractal modeling to the measures reflecting the characteristics of the physical processes such as the element concentration values analyzed in rock and soil samples and caused by the underlying mineralization processes and the other geological processes. The local and regional geological processes may result in geochemical patterns with distinct multifractalities as wall as variable scaling ranges. Separation of these multifractal measures on the basis of both the distinct multifractalities and the scaling ranges will be significant for both theoretical studies of multifractal modeling and its applications. Multifractal scaling breaks have been observed from various multifractal patterns. This paper introduces a technique for separating multifractal measures on the basis of scaling breaks. It has been demonstrated that the method is effective for decomposing geochemical and geophysical anomalies required for mineral exploration. A dataset containing the element concentration values of potassium and phosphorus in soil samples was employed for demonstrating the application of the method for studying the fertilizer and yield optimization in agriculture

关键词： mineralization processes self-similarity geochemical anomaly separation multifractal scaling breaks.

Evolution of the Xiaotian-Mozitan fault and its implications for exhumation of Dabie Hp-UHp rocks

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progress in natural Science:Materials International 2008年第6期18卷 713-722页

作者： biwei Xianga,Yongsheng Wanga,*,Changcheng Li b,Guang Zhu a,Yonghong Shi a aSchool of Resource and environmental Engineering,Hefei university of Technology,Hefei 230009,China bdepartment of earth sciences,university of Western ontario,Ont.,London,canada n6A5b7 School of Resource and environmental Engineering Hefei University of Technology Hefei 230009 China department of earth sciences University of Western Ontario Ont. London Canada N6A5B7

The Xiaotian-Mozitan fault(XMF)located north of the Dabie orogenic belt separates the north Dabie complex to the south from the beihuaiyang low-grade metamorphic rocks to the *** comprises several nW-striking ductile shear zones and brittle *** brit-tle faults obviously overprinted on the ductile shear zones and promoted the development of the volcanic basins in early Cretaceous to the north,which suggests that the brittle faults were normal faults formed in early Cretaceous during doming of the Dabie orogenic *** ductile shear zone superposed on the north Dabie gray gneiss,and it is an important channel where the Dabie Hp-UHp rocks *** obtaining new structural constraint on exhumation of the Hp-UHp rocks,we present here experimental results on the microstructure,quartz C-axis fabrics and the microprobe analyses of *** ductile shear zone was determined to be formed at a temperature of 600-650°C and pressure of 1.1 Gpa by the mineral deformation,microprobe analyses and geobarometry of Si-in-phengite of the mylonite,the results suggest that the mylonite now exposed on the surface experienced an upper amphibolite-facies metamorphism in the lower *** mineral stretching lineation varies from horizontal in the east segment to sub-dip in the *** sense indicators from outcrop and thin sections of orientated specimen and quartz C-axis fabrics suggest that the XMF is a sinis-tral normal *** kinematics analysis of the ductile shear zone indicates that the exhumation of Dabie Hp-UHp rocks is the results of a SE-directed extrusion and an anticlockwise rotation around its eastern pivot simultaneously.

关键词： Xiaotian-Mozitan fault zone Exhumation boundary Ductile shear zone brittle normal fault

Sorption behavior of U(VI), ^(234)U(VI) and ^(238)U(VI) onto fracture-filling clays in beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in China

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Science China earth sciences 2005年第10期48卷 1649-1655页

作者： MIn Maozhong1,2, LUO Xingzhang3, WAnG Ju4, JIn Yuanxin4 & WAnG Rucheng1 1. department of earth sciences, State Key Laboratory of Mineral Deposit Research, nanjing university, nanjing 210093, China 2. Center of Materials Analysis, nanjing university, nanjing 210093, China 3. department of environmental Science and Engineering, nanjing university, nanjing 210093, China 4. beijing Geology Institute, nuclear Industry, beijing 100029, China department of earth sciences State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing China Center of Materials Analysis nanjing university nanjing China department of environmental Science and Engineering nanjing university nanjing China beijing Geology Institute nuclear Industry beijing China

The first results of sorption experiments of U(VI), 234U(VI) and 238U(VI) onto original (unpurified) fracture-filling clays from no.1 monzonitic granite intrusion, beishan area, Gansu province, China are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in China. The present experimental results show that the maximum U(VI) sorption reached 92% at near-neutral pH and the distribution coefficient (Kd) was 1226 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. no preferential sorption of 234U onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

Variation of the Fe/Mn ratio of ferromanganese crusts from the Central north pacific: implication for paleoclimate changes

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progress in natural Science:Materials International 2005年第6期15卷 530-537页

作者： LU Zunli1**, LInG Hongfei1*, ZHOU Feng1, JIAnG Shaoyong1, CHEn Xiaoming1 and ZHOU Huaiyang2(1. State Key Laboratory for Mineral Deposits Research, department of earth sciences, nanjing university, nanjing 210093, China 2. Guangzhou Institute of Geochemistry, Chinese Academy of sciences, Guangzhou 510640, China)department of earth & environmental Science, university of Rochester State Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China department of earth & environmental Science University of Rochester Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Contents of Fe, Mn and other elements in four ferromanganese crusts recovered from the central north pacific are analyzed at high depth-resolution by electron microprobe for reconstructing factors controlling their deposition. Manganese (IV) in hydrogenetic ferromanganese crusts is mainly supplied as colloidal precipitates from the Oxygen Minimum Zone (OMZ), which concentrates high amounts of dissolved Mn (II). The iron is derived from carbonate dissolution and silicate particles of eolian dust. An increase in paleoproductivity during cooler climate would potentially lead to a decrease in Mn deposition due to enlargement of the OMZ which has a “temporary storage” effect for Mn. On the other hand, not affected by the OMZ, the iron entering the Fe-Mn crust would likely increase with the eolian dust input and surface productivity at glacial stages. As a result, the increasing Fe/Mn ratio should indicate a cooling climate. This is supported by the following observations. In the profile of the past 1 Ma, the variations of Fe/Mn ratio coincide with benthic oxygen isotope fluctuation in glacial-interglacial cycles. Three episodes with high Fe/Mn ratios, approximately at 2.6, 1.8 and 0.8 Ma, are detected within the past 3 Ma and coincide with major climate transitions and cooling events. The secular evolution pattern of Fe/Mn ratio in the Cenozoic is similar to the pb isotope evolution which is mainly controlled by eolian dust and related to climate. The Fe/Mn evolution pattern is also broadly consistent with the global deep-sea oxygen isotope records. Therefore, Fe/Mn ratio recorded in the ferromanganese crusts may be a new proxy for climate change.

关键词： Fe/Mn ratio ferromanganese crust central north pacific paleoclimate.

principle of small target detection for hyperspectral imagery

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Science China earth sciences 2007年第8期50卷 1225-1231页

作者： GEnG XiuRui1,2,3 & ZHAO YongChao2,3,4 1 Research Center for Remote Sensing and GIS, department of Geography, beijing normal university, beijing 100875, China 2 State Key Laboratory of Remote Sensing Science, Chinese Academy of sciences, beijing 100101, China 3 Institute of Erectronics, Chinese Academy of sciences, beijing 100080, China 4 Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem sciences university of California berkeley, CA 94720-3114, USA 1. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing 100875 China 2. State Key Laboratory of Remote Sensing Science Chinese Academy of Sciences Beijing 100101 China 3. Institute of Erectronics Chinese Academy of Sciences Beijing 100080 China 4. Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem sciences University of California Berkeley CA 94720-3114 USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection