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    题名 作者 年代 出处 被引量
1Edge Effect Correction in the S-A Method for Geochemical Anomaly Separation显示文摘Anomaly separation using geochemical data often involves operations in the frequency domain, such as filtering and reducing noise/signal ratios. Unfortunately, the abrupt edge truncation of an image along edges and holes (with missing data) often causes frequency distribution distortion in the frequency domain. For example, bright strips are commonly seen in frequency distribution when using a Fourier transform. Such edge effect distortion may affect information extraction results; sometimes severely, depending on the edge abruptness of the image. Traditionally, edge effects are reduced by smoothing the image boundary prior to applying a Fourier transform. Zero-padding is one of the most commonly used smoothing methods. This simple method can reduce the edge effect to some degree but still distorts the image in some cases. Moreover, due to the complexity of geoscience images, which can include irregular shapes and holes with missing data, zero-padding does not always give satisfactory results. This paper proposes the use of decay functions to handle edge effects when extracting information from geoscience images. As an application, this method has been used in a newly developed multifractal method (S-A) for separating geochemical anomalies from background patterns. A geochemical dataset chosen from a mineral district in Nova Scotia, Canada was used to validate the method.Ge Yong Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences & Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Cheng Qiuming Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Earth Systems and Mineral Resource Engineering Lab, China University of Geosciences, Wuhan 430074, China Zhang Shenyuan Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Department of Resource and Earth Science, China University of Mining & Technology, Beijing 100083, China 2004Journal of China University of Geosciences2004,15,4:28
2Sinobaatar gen. nov.: First multituberculate from the Jehol Biota of Liaoning,Northeast China显示文摘A multituberculate skeleton from the Lower Cretaceous Yixian Formation at Dawangzhangzi, Lingyuan City, Liaoning Province, Northeast China, provides new morphological information for early multituberculates. The specimen is the holotype of Sinobaatar lingyuanensis gen. et sp. nov. It has a narrow skull that lacks the superorbital crest or postorbital process. The dental formula is 3·?·5·2/1·0·3·2. The dental morphology, especially that of cheek teeth, of S. lingyuanensis is similar to that of Eobaatar, which places it in the family Eobaataridae. The postcranial skeleton of Sinobaatar is similar to that of other multituberculates. As in Holotheria, Metatarsal V of Sinobaatar articulates only with the cuboid and has no contact with the calcaneus, which probably represents the primitive condition of multituberculates. Nine carpals of Sinobaatar resemble those of Zhang-heotherium, except the centrale being larger than the trape-zoid. The dental features of Sinobaatar show again that eo-baatarids areHU Yaoming & WANG YuanqingInstitute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 10044, China American Museum of Natural History, New York, NY 10024, USA Biology Program (Ecology, Evolutionary Biology, and Behavio 2002Chinese Science Bulletin2002,47,11:17
3Fractal and Multifractal Modeling of Hydrothermal Mineral Deposit Spectrum: Application to Gold Deposits in Abitibi Area, Ontario, Canada显示文摘A number of fractal/multifractal methods are introduced for quantifying the mineral deposit spectrum which include a number-size model, grade-tonnage model, power spectrum model, multifractal model and an eigenvalue spectrum model. The first two models characterize mineral deposits spectra based on relationships among the measures of mineral deposits. These include the number of deposits, size of deposits, concentration and volume of mineral deposits. The last three methods that deal with the spatial-temporal spectra of mineral deposit studies are all expected to be popularized in near future. A case study of hydrothermal gold deposits from the Abitibi area, a world-class mineral district, is used to demonstrate the principle as well as the applications of methods proposed in this paper. It has been shown that fractal and multifractal models are generally applicable to modeling of mineral deposits and occurrences. Clusters of mineral deposits were identified by several methods including the power spectral analysis, singularity analysis and the eigenvalue analysis. These clusters contain most of the known mineral deposits in the Timmins and Kirkland Lake camps.Cheng Qiuming Department of Earth and Atmospheric Science, Department of Geography, York University, Toronto, Canada M3J1P3 Faculty of Earth Resources, China University of Geosciences, Wuhan 430074 2003Journal of China University of Geosciences2003,14,3:13
4Multifractal modelling and spectrum analysis: Methods and applications to gamma ray spectrometer data from southwestern Nova Scotia, Canada显示文摘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 useful thresholds for separating the power-spectrum values into two types of patterns to reflect different influences of possible geological processes such as hydrothermal altera- tion in the study area.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 2006Science China Earth Sciences2006,49,3:8
5Selection of Multifractal Scaling Breaks andSeparation of Geochemical andGeophysical Anomaly显示文摘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 inCheng Qiuming Department of Earth and Atmospheric Science, Department of Geography, York University, Toronto, Ontario, Canada, M3J 1P3 2001Journal of China University of Geosciences2001,12,1:7
6Effects of Soil Fertility and Atmospheric CO_2 Enrichment on Leaf, Stem and Root Dark Respiration of Populus tremuloides显示文摘An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) of Populus tremuloides. Overall, area-based day-time leaf Rd (Rda) was significantly greater at elevated than at ambient CO2 in high-fertility soil, but not in low-fertility soil. Mass-based leaf Rd (Rdm) was overall greater for high- than for low-fertility soil grown trees at elected, but not at ambient CO2. Nighttime leaf Rd. and Rdm were unthected by soil fertility or CO2, nor was stem Rda, which ranged from 1.0 to 1.4 μmol m-2 s-1 in the spring and 3.5 to 4.5 μmol m-2 s-1 in the summer. Root Rda. was significantly higher in high- than in low-fertility soil, but was unaffected by CO2. Since biomass production of P. tremuloides will be significantly greater at elevated CO2 while specific Rd will either increase or remain unchanged, we predict that carbon loss to the atmosphere through respiration from this ecologically important species would increase at higher CO2. Soil fertility would also interact with elevated CO2 in affecting the carbon flow in the plant-soil-air system.X. Z. WANG P. S. CURTIS and C. S. VOGEL Columbia University, Palisades, New York 10964-8000 (USA) The Ohio State University, Columbus, Ohio 43210-1293 (USA) University of Michigan Biological Station, Pellston, Michigan 49769 (USA) 2001Pedosphere2001,11,3:6
7Fractal Correction of Well Logging Curves显示文摘It is always significant for assessing and evaluation of oil bearing layers, especially for well logging data processing and interpretation of non marine oil beds to get more accurate physical properties in thin and inter thin layers. This paper presents a definition of measures and the measure presents power law relation with the corresponded scale described by fractal theory. Thus, logging curves can be reconstructed according to this power law relation. This method uses the local structure nearby concurrent points to compensate the average effect of logging probes and measurement errors. As an example, deep and medium induced conductivity (IMPH and IDPH) curves in ODP Leg 127 Hole 797C are reconstructed or corrected. Corrected curves are with less adjacent effects through comparison of corrected curves with original one. And also, the power spectra of corrected well logging curve are abounding with more resolution components than the original one. Thus, fractal correction method makes the well logging more resoluble for thin beds.Li Qingmou Cheng Qiuming Institute of Geology & Geophysics, Chinese Academy of Sciences, Beijing 100101 Department of Earth and Atmospheric Science, York University, Toronto, Ontario, Canada, M3J 1P3 2001Journal of China University of Geosciences2001,12,3:5
8Quantum dynamics study for reaction of H_2 + OD→H + HOD显示文摘TIME-dependent (TD) quantum wave packet theory, with a relatively small amount of computational effort, has been widely used in quantum dynamics calculation of atom and molecule reaction scattering. Many computational scaling advantages of the TD method can be found apparently in polyatomic system. In this note, by using the TD quantum wave packet method with the potential-averaged 5D model (PA5D), we give the calculated results of reaction probabilities, cross sections and rate constants for the H2 + OD reaction. The energyprojection method is used to transform the TD wave function into the TI (energy-indepen-ZHANG Yici, ZHANG Yanbing, ZHANG DeshengZHANG Qinggang, Dong H. Zhang and John Z. H. Zhang1. Department of Physics, Shandong Teachers University, Jinan 250014, China 2. Department of Chemistry, New York Uni versity, New York 10003, USA 1997Chinese Science Bulletin1997,42,2:4
9On conformal measures for infinitely renormalizable quadratic polynomials显示文摘We study a conformal measure for an infinitely renormalizable quadratic polynomial. We prove that the conformal measure is ergodic if the polynomial is unbranched and has complex bounds. The main technique we use in the proof is the three-dimensional puzzle for an infinitely renormalizable quadratic polynomial.HUANG Zhiyong~1 JIANG Yunping~(2,3) & WANG Yuefei~3 1. School of Information,Renmin University of China,Beijing 100872,China 2. Department of Mathematics,Queens College,City University of New York,NY 11367,USA Department of Mathematics,Graduate School,City University of New York,New York,NY 10016,USA 3. Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100080,China 2005Science China Mathematics2005,48,10:4
10Nitrite-derived nitric oxide by xanthine oxidoreductase protects the liver against ischemia- reperfusion injury显示文摘It was demonstrated that xanthine oxidoreductase (XOR), during ischemia, catalyzes the formation of nitric oxide (NO) from nitrite (NO2-) and this NO2--derived NO protects the isolated perfused rat heart against the damaging effects of ischemia-reperfusion (I/R) when conventional nitric oxide synthase (NOS) -dependent NO production is impaired. Liver is one of the organs with the highest XOR concentration. This study was designed to determine whether NO2--derived NO by XOR protects liver against I/R injury in vivo. For its minute amounts and active reactivity, NO can not be detected directly in real time in vivo by this time. We have to prove the above hypothesis indirectly. METHODS:Wistar rats were pretreated with saline, NOS inhibitor L-NAME (10 mg/kg intravenously), XOR inhibitor allopurinol (1.5 mg/kg orally), L-NAME +allopurinol and NO scavenger carboxy-PTIO (0.6 mg/kg intravenously) respectively (12 animals per group). And then, they were subjected to total liver ischemia for 40 minutes followed by reperfusion. Blood samples and liver tissues were obtained for analysis after 3 hours of reperfusion. Survival was also investigated. RESULTS:Allopurinol-treated animals exhibited further increased serum alanine aminotransferase (ALT) levels and liver myeloperoxidase (MPO) activities, but further decreased liver adenosine triphosphate (ATP) stores after I/R compared to saline-treated counterparts (830.5±108.3 U/L, 56.5±11.0 U/mg protein and 1.93±0.47 μmol/g vs. 505.8± 184.2 U/L, 41.5±10.2 U/mg protein and 3.05±0.55 μmol/g respectively, P<0.01, P<0.05 and P<0.01 respectively). The hepatocyte injury was further exacerbated and the overall survival rate was significantly decreased after I/R in animals given by allopurinol compared to those pretreated by saline (P<0.05). L-NAME and allopurinol co-treated animals exhibited more severe liver injury (P<0.05 and P<0.01) and a further decreased overall survival rate (P<0.05) compared to L-NAME or allopurinol alone-treated counterparts, but they were not different from carboxy-PTIO treated animals (P>0.05). CONCLUSION:NO2--derived NO by XOR in the hypoxic and acidic environment induced by hepatic I/R protects the liver against I/R injury in vivo.Department of General Surgery ( Lu P, Wang CY and Chen DD), and Department of Radiology (Liu F), Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China Cold Spring Harbor Laboratory, New York 11724, USA ( Yao Z) General Surgery Laboratory, Union Hospital, Tongji Medical College , Huazhong University of Science and Technology, Wuhan 430022 , China (Tian Y, Zhang JH and Wu YH) 2005Hepatobiliary & Pancreatic Diseases International2005,4,3:4
11直接评估吗啡刺激糖尿病人隐静脉内皮一氧化氮释放减少显示文摘to directly measure in real time basal and stimulated levels of NO released from human saphenous vein endothelium and to quantify the expression of the μopiate receptor, which has been linked with NO release. METHODS: Saphenous vein segments from patients with type 2 diabetes ( n = 12) and patients without diabetes (n =8) were obtained. The release of NO was measured directly from the endothelium using a NO-specific amperometric probe. NΩ-nitro-L-arginine methyl ester (L-NAME, 0.1 mmol/L), a NO synthase (NOS) inhibitor, or morphine (1 μmol/L), a stimulant, was administered and the measurements were repeated. Values were reported relative to the mean initial measurement of NO release from diabetic endothelium, which was defined as the relative zero level of NO release. A RT-PCR was then performed on the endothelium to measureμ opiate receptor expression. RESULTS: Diabetic patients (n = 12) showed a relative and significantly diminished basal level of released NO, (0.049± 0.012) nmol/L, comparedThomas V BILHNGER, James A VOSSWINKEL, Patrick CADET, Christos M RIALAS, Harold I MAGAZINE, George B STEFANO(Division of Cardiothoracic Surgery, Department of Surgery, University Hospital and Medical Center, HSC, T19-080, Stony Brook, New York 11794-8191 Neuroscience Research Institute, State University of New York College at Old Westbury, Old Westbury, New York , USA) 2002Acta Pharmacologica Sinica2002,23,2:3
12Selective flocculation of fines显示文摘A number of factors that affect selective flocculation of fines have been identified and the effect of some of parameters on process behavior has been explained with the help of a few case studies. Experiments with francolite montmorillonite and francolite palygorskite mixtures indicated that francolite recovery depends on pH and the type of dispersant. The results showed that removal of multivalent ionic species on clay mineral surfaces seems to enhance flocculation, and separation efficiency increases as Ca 2+ ions are removed from the surface. When chalcopyrite and quartz are present together, it is however necessary to clean the flocs obtained to remove entrapped quartz.P.Somasundaran, V.RunkanaLangmuir Center for Colloids and Interfaces, Columbia University, New York, NY 10027, USA 2000中国有色金属学会会刊:英文版2000,10,S1:3
13Geochemical and Geophysical Data Processing Aided by“Multifractal-Spectrum”Filters for GIS-Based Mineral Exploration显示文摘A recently developed method, on the bases of “multifractal spectrum” filters for mineral exploration, is introduced in this paper. The “multifractal spectrum” filters, a group of irregularly shaped filters that are constructed on each processed datum, can be used to separate various types of geochemical and geophysical anomalies. The basic model, with an emphasis on the GIS based implementation and the application to the geochemical and geophysical data processing for mineral exploration in southern Nova Scotia, Canada, indicates its advantage in the separation of multiple anomalies from the background.Xu Yaguang Cheng Qiuming Department of Earth and Atmospheric Science, York University, North York, Ontario, M3j 1P3 Canada 2000Journal of Earth Science2000,19,2:2
14Modified High-order Upwind Method for Convection Diffusion Equation显示文摘Abstract In this paper, we study the high-order upwind finite difference method for steady convection-diffusionproblems. Based on the conservative convection-diffusion equation, a high-order upwind finite difference schemeon nonuniform rectangular partition for convection-diffusion equation is proposed. The proposed scheme is inconversation form, satisfies maximum value principle and has second-order error estimates in discrete H^1 norm.To illustrate our conclusion, several numerical examples are given.Wei-dong ZHAO, Dong LIANGSchool of Mathematics and System Sciences, Shandong University, Jinan 250100, ChinaDepartment of Mathematics and Statistics, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada 2002Acta Mathematicae Applicatae Sinica2002,18,1:2
15PRIMARY CELL CULTURE FOR EMBRYONIC CARDIAC MYOCYTES OF MEXICAN AXOLOTL AND DISTRIBUTION OF DESMIN AND VIMENTIN显示文摘INTRODUCTIONTheaxolotlprovidesavaluablemodelsystemforstudyingmuscledevelopmentandfunction.Electronmicroscopyrevealsthataxolot...Zhu Yongze, Robert W Zajdel *, Margaret E Fransen *, Larry F Lemanski *(Department of Anatomy, Medical College of Yangzhou University, Yangzhou, 225001 Chian Department of Anatomy and Cell Biology, State University of New York, Health Science Cent 1999中国组织化学与细胞化学杂志1999,8,1:2
16BILEVEL PROGRAMS WITH MULTIPLE FOLLOWERS显示文摘In this paper, we are concerned with bilevel programs with multiple followers. Three new solution concepts are introduced for a bilevel programming problem with multiple followers. First, one sufficient condition for the existence of a Nash equilibrium reaction is presented and the continuity of the reaction set is discussed. Next, we show that a class of bilevel programs with multiple followers can be solved via solving a corresponding bilevel program with a single follower. Finally on the basis of a theorem proved via applying the Kuhn-Tucker conditions to the inner game problem, a branch and bound technique is developed for bilevel program with multiple followers. Two numerical examples are also given to illustrate the algorithm.WANG Qian(Department of Industrial Engineering, State University of New York at Buffalo,Buffalo, NY 14260, USA)YANG Fengmei(Depariment of Applied Mathematics and Physics, Beijing University of Chemical Technology,Beijing 100029, China)WANG Shouyang(Instit 2000Systems Science and Mathematical Sciences2000,13,3:2
17Capahility and Quality in HigherEducation 显示文摘John Stephenson and Mantz Yorke 1998Kogan1998,,5:1
18Interval maps, factors of maps, and chaos显示文摘Auslander J and Yorke J 1980Tohoku Math Journ1980,32,:1
19Energy use, environmental loading and sastainability: an energy analysis of italy 显示文摘emergy and York : John Ulgiati S Odum H T Bastianoni S 1994Ecological Modelling1994,73,:1
20Looks matter in developing consumer - brand relationships 显示文摘Hayes J B Alford B L Silver L and York R P 2006The Journal of Product and Brand Management2006,15,5:1
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