摘要:If we think that the theory of “Continental Drift and Plate Tectonics” is the most representative geologic innovation of the 20th century, then, the international geological science is now undertaking a new reform, changing from a past sole science to interdisciplinary scientific research of “Global Change” and the “Earth System Science Theory”. Moreover, such kinds of multidisciplinary integration not only involve geologic fields, but also integration with atmospheric science, oceanography, and biology,leading the “Earth System Science Theory” to a new stage . Actually, many significant geologic or climatic events on earth, especially the Cenozoic tectonic uplifts of the Tibetan Plateau, closely link to the interactions among lithosphere, hydrosphere, atmosphere, and biosphere. If we still take a conservative view to cope with the tectonic uplift of the Tibetan Plateau and its environmental effects, it will be difficult to have new development in geology science.
摘要:The genesis of polymetallic deposits in southern Altay, NW China has been disputed between a syngenetic seafloor hydrothermal process and an epigenetic orogenic-type mineralization. The Sarekuobu gold deposit occurs as NW-trending veins in the Devonian Kelan volcanicsedimentary basin of the Altay orogenic belt. To constrain the metallogenic age, biotite40Ar/39Ar geochronological analysis was carried out in this paper. One biotite sample separated from the gold-bearing lodes yielded40Ar/39Ar isotopic plateau age of (213.5 ± 2.3) Ma, representing the mineralization age of gold-polymetallic sulfides. By summarizing the available isotopic ages and geochemistry data, a significant collision event and related metallogeny during the Triassic in the Altay Orogen is recognized. In combination with the characteristics of ore geology and fluid inclusion geochemistry, the Sarekuobu gold deposit can be determined as an epigenetic orogenictype gold deposit.
摘要:Great changes occurred in the earth's surrounding environments during the Permian-Triassic (P-Tr) transition and resulted in the collapse of land and marine ecosystems. Thus, the most severe mass extinction in the earth's history appeared across the P-Tr boundary. Wildfire, as a key ecosystem driver and climate change indicator, is seldom reported in the documents of the pre-Quaternary researches. In this study, a 521 ka record of wildfire during the P-Tr mass extinction was recurred through the black carbon (BC) and combustion-derived polycyclic aromatic hydrocarbons (PAHs) records in the GSSP section of Meishan. There were frequent wildfires in the 163 ka of history just before the P-Tr mass extinction and the most intensive one occurred in the mass extinction event beds. No combustion records were found in the beds above mass extinction line and a wildfire gap (lasting 358 ka) was recognized in the Early Triassic. Wildfire gap may be not a local phenomenon, but a response of global climatic and environmental changes. Wildfire would vanish accompanied by the destruction of land vegetation and abrupt drop of atmospheric oxygen. Therefore, Meishan P-Tr wildfire gap can be used as an indicator of the mass extinction.
摘要:The Gangdeer Mountains, located in the northwest margin of the Ordos Plateau, is a key area for understanding the formation and evolution of the drainage system in response to neotectonic movement. Two terraces (T-1 and T-2) composed of fluviallacustrine deposits have been formed along the west piedmont of the Gangdeer Mountains. Dating of T-2 yields ages of 82.23±9.88 ka (OSL), 116.76±11.41 ka (OSL) and 467±124 ka (ESR) for the upper, middle and lower deposit cropout, respectively. The longitudinal profile of both terraces indicates an arch-form, high in the middle of the Gangdeer Mountains and low in the area adjacent to Hetao and Yinchuan basins, suggesting the effects of mountain uplift. Lakes coexisting with rivers in the Middle to Late Pleistiocene, gradually shrank as the Gangdeer Mountains were uplifted along the Zhuozi Mountains Fault Zone (mainly along the Eastern Piedmont Fault of Gangdeer Mountains) and the zone of uplift propagated northward. Eventually, the rivers gradually prevailed over the lakes, leading to formation of the Yellow River, and its two terraces and their fluvio-lacustrine deposits.
关键词:northwestern margin of the Ordos Plateau;river terrace;neotectonics;Yellow River;fluvial-lacustrine deposit
BI Lisi,HE Honglin,XU Yueren,WEI Zhanyu,SHI Feng,SUN Haoyue
Vol. 53, Issue 6, Pages: 37-44(2014)
摘要:Longitudinal profiles of the gullies in different tectonic settings and different evolutionary stages show different morphological forms which can be fitted ordinarily by such mathematical functions as linear function, exponential function, logarithmic function and power function. These forms reflect the response of the gullies to the factors such as the time, the climate, the bedrock of the riverbed and the tectonic movement. Based on DEM data, 64 gullies across the Huoshan piedmont fault are extracted and their profiles are fitted by four types of mathematical functions above. The bestfitting mathematical function for each gully is selected and the responding characteristics of the gullies to the tectonic movement of the fault are analyzed. The result shows that the gullies are in their infancy which is exhibited by their linear forms or the exponential forms with very small concavity. This is due to the response of the gullies to the constant normalfault movement of the Huoshan piedmont fault since Pliocene,especially the strong activities with short interval in Holocene.
关键词:longitudinal profiles of the gullies;mathematical fitting functions;DEM data;the Huoshan piedmont fault;responses to the tectonic movement
摘要:The Pearl River Delta, formed since the Late Pleistocene, is one of the major delta in the world. There are abundant microfaunas preserved in sediments of the Pearl River Delta, which have been proved to be essential for reconstructing Quaternary environment. In this study, Microfaunas (foraminifers and ostracods) of borehole PRD17 from the eastern Pearl River Delta have been analyzed quantitatively. A total of 29 foraminiferal species belonging to 14 genera and 17 ostracod species referred to 14 genera were identified. They can be divided into three different groups with respect to their ecological ranges. Based on the comprehensive analysis of microfaunas, lithological and sediment grainsize characteristics of core samples, palaeoenvironmental changes since the Late Pleistocene can be reconstructed. Before ~43 400 cal a B.P., a fluvial environment was recorded in the borehole until the late Wurm Interglacial Stage when the first Quaternary marine unit began to lie down. During this transgressive interval, three short-term environmental fluctuations of water depth can be recognized base on microfaunal data. A peak transgression of the Late Pleistocene was marked between ~35 400 and 30 900 cal a B.P.. Since about ~25 900 cal a B.P., sea waters gradually retreated from the study area and the Upper Pleistocene sediments were subsequently subaerially exposed during the Last Glaciation Maximum, which is indicated by a mottled clay layer in the core. Around ~6 000 cal a B.P., the postglacial sea level rise initiated a new phase of the Holocene sedimentation. This timing was later than in other parts of the Pearl River Delta because core site is located in the GuangzhouPanyu fault block with a higher elevation during the Early-Middle Holocene. A supralittoral-zone environment developed during the first phase of Holocene sedimentation. Since ~3 700 cal a B.P., the study area gradually changed into a tide flat environment with microfossils sporadically present.
关键词:the Pearl River Delta;foraminifers;ostracods;Late Quaternary;palaeoenvionment
摘要:According to pollen assemblage analysis of 3 boreholes in Xiamen Bay-Jiulong River Estuary region, combined with the results of sedimentary facies and dating analysis, this paper explore the paleoclimatic and paleoenvironmental evolution in this area since Late Pleistocene. Pollen analysis show that: since the early stage of MIS4, the main paleoclimatic evolution of the region includes the fluctuations and changes such as: slightly dry-cold in Late Pleistocene, drywarm then wet-warm in early Mid Holocene(8~5.5 cal. ka BP),wet-warm then slightly moderatedry climate in late Mid Holocene(5.5~2.5 cal. ka BP) and wet-warm in Late Holocene(since 2.5 cal. ka BP). Global scale substantial cooling event in Late Pleistocene impacts clearly in this area. Characteristic of the climate change in Holocene is that the temperature and humidity varies fluctualy between some ranges. The human activity infects clearly the vegetation form since Late Holocene.
关键词:pollen;paleoclimate;Quaternary;Xiamen Bay;Jiulong River Estuary
摘要:High frequency sea-level fluctuations and their response to global change in the Pearl River Delta, adjacent to South China Sea, is still an open question due to uncertain dating and complicated facies changes. In this paper, we correlate the sediments of three cores, selected from the delta, using magnetic susceptibility stratigraphic and cycle stratigraphic methods. The geomagnetic inclination change recorded in sediments of core SX97 is compared with the geomagnetic paleosecular variation profiles recorded in sediments from the Shuangchiling Lake in Hainan Island, Erhai Lake in Yunnan province and Biwa Lake in Japan. Based on this correlation, agedepth models of three cores are then established. The magnetic grain size indicator χARM/SIRM, coeval with the susceptibility, is used to serve as a proxy of sea-level fluctuations during the Holocene. Two high sea-level episodes occur at 9.1-7.7 ka BP and 4.0-3.2 ka BP, and several sharp sea-level falls appear at about 1.2-1.5 ka BP, 3-3.2 ka BP, 4.0-4.75 ka BP, 5.25-5.75 ka BP, 6.2-6.3 ka BP and 7.25-7.75 ka BP, corresponding to impacts of cold climate in the North Atlantic and weakened monsoonal activity in Asia, respectively.
摘要:Many studies focus on the oxidation of arsenopyrite which results in the formation of acid mine drainage (AMD) rich of As, but effects of pH and Fe2+ on arsenopyrite bio-oxidation are rarely available. A strain of Acidithiobacillus ferrooxidans (A.f.) isolated from the AMD of Dabaoshan and a mineral arsenopyrite were used to study the biooxidation of arsenopyrite. Experiments were designed to compare the difference between abiotic oxidation and biooxidation of arsenopyrite in pH2.00, 3.00 and 3.50 with or without additional Fe2+conditions in a period of 30 days. The concentrations of As ion, Fe2+ and pH values during the experiments were determined The results showed the lower original pH value the higher concentration of As ion in the result solution of biooxidation without additional Fe2+. The concentration of As ion in the result solution of the original pH2.00 is about 15 times of that in the original pH3.50. A lower pH value can accelerate the biooxidation of arsenopyrite. The additional Fe2+can keep the pH value of bio-oxidation solution in a condition of lower than 4.00, which promotes the biooxidation of the arsenopyrite and concentration of As ion in the result solution. The results indicate that adding some alkaline substances in the acid mine drainage to increase its pH value can reduce its Fe2+concentration,decrease the bio-oxidation rate of arsenopyrite and reduce the concentration of As ions.
关键词:Acidithiobacillus ferrooxidans;arsenopyrite;oxidation;acid main drainage
摘要:Hydrocarbon microseepage induced anomaly of surface and near surface is the direct evidence for oil & gas deposit. The detection of hydrocarboninduced anomaly by remote sensing image interpretation is fast, efficient and safe. ASTER Near Infrared data were used to interpret hydrocarboninduced carbonate minerals. Principal component analysis (PCA), density slicing and false color composition were adopted to distinguish the goal area of clay and carbonate minerals. Four principal components showed outstanding spectral response of hydrocarboninduced clay and carbonate minerals: 5689-PC2 (the second principal component of input bands 5689), 1589-PC3, 1689-PC3 and 1348-PC3. Then, density slicing (X+2σ) was used to highlight the pixels with the largest DN (digital number) of PC images as the area of carbonate minerals. The distinguished area was categorized into the first and second classes due to the frequencies of overlay. The result suggests that hydrocarbon microseepage induced mineral assemblage is related closely to the surface sediments. Compared with the anomalous area of ETM+ data, the distinguished area from ASTER data has almost the same distribution.
关键词:ASTER;hydrocarbon microseepage;carbonate minerals;information enhancement and interpretation
摘要:Matching pursuit time-frequency analysis has better time-frequency resolution compared to short-time Fourier transform, continuous wavelet transform, and generalized S transform, but the traditional greed iterative algorithm has lower computation efficiency. The Morlet wavelet is chosen as timefrequency atoms to achieve the matching pursuit due to the good property of scale parameter. The scale parameter has strong control action on the form of time-frequency atom, thus has strong control action on the matching character between signal and time-frequency atom, through comparing and analyzing the forms of timefrequency atoms based on different scale parameters and the projection values of signal onto different time-frequency atoms with the same frequency, phase and time-delay parameters but different scale parameters. The 1D optimization for scale parameter is done with the frequency, phase and time-delay parameters calculated by Hilbert transform as the parameters of time-frequency atoms. Then the parameters are only needed to be fine-adjusted, and the computation efficiency is improved. The effectiveness of algorithm is tested by model data, and the algorithm is also tested on application of denosing and inversion for thin layer thickness.
WANG Zhenghai,FAN Chen,HE Fengping,ZU Yuchuan,WANG Lei,WANG Juan
Vol. 53, Issue 6, Pages: 93-97(2014)
摘要:The methods of multispectral imagery processing, such as artificial neural network classification and independent component analysis are not applicable to high spectral imagery, because of “Hughes Phenomenon” (when training samples are fixed, the classification accuracy decreases with the increase of feature dimension) and classification accuracy under small study samples can not be effectively solved for high dimensional data. A decision-tree-based multiclass support vector machines is proposed and applied in spectral classification for the multi-classification problem of surface rocks collected from the Beiya gold mine, Heqing County, Yunnan Province. The results show that the average classification accuracy rate can be above 93.75%, suggesting that multiple classification based on decision tree classification support vector machine (SVM) can be applied to spectral classification of rocks.
关键词:hyperspectral rock classification;feature extraction;support vector machine (SVM);multi-class classification;decision tree
摘要:Tensile strength is often ignored in traditional research of engineering geology and soil mechanics, however, tensile strength plays a critical role in the stability assessment of red soil collapse, soil dam, embank ment, subgrade and rubbish buried field. The tensile strength test apparatus developed by authors is used to explore two types of granite residual soil existing widely in South China, and shear strength parameters of cohesive granite residual soil are obtained through direct shear test, then the mechanism of granite residual soil's tensile strength is analysed. The results show that granite residual soil's tensile strength increases with the rising water content and dry unit weight, however the range becomes less with the rising dry unit weight and water content; the tensile of sandy granite residual soil is usually lower than that of cohesive granite residual soil, and cohesive granite residual soil's tensile strength increases with cohesion,but has little relation with angle of internal friction. The analysis of granite residual soil's tensile strength indicates that joining forces between soil particles are the main source of tensile strength, which includes joining forces with direct contact, microcosmic joining force without direct contact, and joining force aroused through cement or Gas-Liquid shrink film.
关键词:granite residual soil;tensile strength;uniaxial tensile strength tester;mechanism of tensile strength
摘要:Materials of reclaiming land is one of the main factors effecting on consolidation efficiency which can be decreased by fine particles. The characteristics of the granule and mineral compositions, physical and chemical properties of dredger fills from various coastal areas were obtained by experiments. It was shown that the dredger fill from the Daya Bay engineering field is similar to that from other areas, which have many fine particles in compositions. The Daya Bay dredger fill is characterized by high plastic index, high cation exchange capacity (CEC), and high organic matter content. Furthermore, it was concluded that the Daya Bay dredger fill is one kind of high liquid clay with the same as that in some other high clay content areas. Besides these, minerals in different dredger fills were not obviously different due to the complex environment of sediment distribution in bay areas. The cementation effect of the fills with high content of sodium and chloride ions in various coastal areas results in unstable chemical and physical properties of the soils.
摘要:Electrokinetics in combination with vacuum preloading has obtained good effect on consolidation of soft soil. Experimental studies on changes in electrical properties are conductive to optimize parameters and evaluate the effects of consolidation. Three control experiments are conducted to compare the effectiveness of vacuum preloading combined electro-osmotic strengthening and vacuum preloading combined electrokinetics strengthening, as well as investigating the effect of CaCl2injection at different time on experimental effects. The experimental results demonstrate that CaCl2injection can increase the current in soil, improve soil conductivity, lower the resistance between electrodes and interface, improve the drainage rate and decrease energy consumption, thereby improving the consolidation effectiveness. The injection way plays a significant role on experimental effect. Appropriately adding a single injection dose can accelerate drainage and choosing the appropriate time period and injection method can effectively control energy consumption and increase efficiency.
MO Mo,QIU Zhili,ZHANG Yuefeng,LI Liufen,WU Mo,LUO Han
Vol. 53, Issue 6, Pages: 118-126(2014)
摘要:Based on abundant archaeological findings as well as documentary records, three climaxes of colored gems and jades utilization were indentified in Chinese history, which were naturally formed in the communication between Chinese and foreign cuture along ancient silk roads. The first climax occurred in Han-Wei Period with colored jewelries such as turquoise, lapis lazuli, red gems, coral, amber, agate, etc. in the archaeological findings. The second climax were in Tang-Song (Liao) Dynasty being accompanied by the utilization of the most precious gems like ruby, sapphire and topaz as well as those in the first climax. The third climax occurred in Ming-Qing Dynasty with important gems & jades such as ruby, sapphire, emerald, cat's eye, lapis lazuli, tourmaline and green jadeite. The first peak utilization of colored gems and jades is initiated by Chinese people exploring central Asia through Northern Silk Road. The second is rooted in the prosperous Sino-western commercial and cultural connections during Tang-Song (Liao) Dynasty. The third climax, being born with relatively complex reasons, first derived from the active goods trade in Ming Dynasty along the Maritime Silk Road because of China's open to the west, and finally formed in the military pressure from western countries in the Qing Dynasty. In the third climax, introduction of green jadeites along Southeast Maritime Silk Road led Chinese jade culture into a new period with a transition from nephrite-dominated to jadeite & nephrite-dominated jade culture. Archaeological findings reveal that China's colored gems & jades culture was developed in the communication between Chinese and western culture along ancient silk roads. In the meantime, major colored gems and jades were imported from overseas countries. So the colored gems & jades culture in China, valuing more color rather than texture, is a kind of exotic culture.
YANG Jiong,QIU Zhili,PENG Shuzhen,MO Mo,JIN Xiaoting,LI Zhixiang
Vol. 53, Issue 6, Pages: 127-134(2014)
摘要:With recent establishment of the Yangtze economy belt in national development strategy which involves nine provinces and two municipalities, China will form a new development pattern consisting of the existed longitudinal economy belt along coastal regions and a new latitudinal economy belt along the Yangtze river. This paper analyzed the potential influence of the establishment of the Yangtze economy belt on China's jewelry industry, and discussed the relationship between jewelry industry layout and regional economy development strategy, based on current situation and problems in the jewelry industry in China. We believe that the establishment of the Yangtze economy belt, forming a T-shape economy development pattern consisting of longitudinal coastal belt and latitudinal river belt, will promote the economy through deepening reforms and opening-up in economy from a linear belt to a planar region and from eastern coastal regions to western inland regions. This change could potentially contribute to the rapid development and transformation and upgrading henceof Chinas jewelry industry during transition from a three-pillar pattern to all around development in China. Furthermore, the establishment of the Yangzte economy belt will drive local jewelry industry in central and western regions to step into the international mainstream market. Some new regional brands and jewelry centers along the middle and upper reaches of the Yangzte River will come up in the help of local advantages in resources, finance and talented people, which will promote the core competitiveness of China's jewelry industry with low growth. In the meantime, the rise of the jewelry industry in Yangzte River area will push the industry in coastal area to upgrade and transform themselves to increase their competitiveness.
关键词:the Yangtze River economy belt;jewelry industry;industrial distribution pattern;clustering
摘要:The RBF neural network for classification is applied in face recognition. With two important criterion for estimating the initial width of RBF unit, the width can control the generalization ability of RBF neural network classifier. PCA method to the training sample set the projection to the face space, to reduce dimension. On the basis of the PCA transform, an optimal subspace classification makes the distance between the classes to maximize the ratio of the distance using FLD method. Simulation is conducted on the ORL database, and its results show that the algorithm is efficiency and effectiveness.
摘要:Aiming at automatic generation control (AGC) design of a class of interconnected power systems when the expansion is done on line, an optimized selfhealing control method, which can guarantee the expanded system to steady run when the topological structure is changed suddenly, is proposed by adopting dynamic output feedback and genetic algorithm. By means of modeling to the expansion system, the robust decentralized controller keeping the system structure to be stable is designed by using LMI method. Genetic algorithm is used to optimize the related parameters emerged in the process to solve, and the blindness to choose the parameters is avoided. In the optimal process, the fitness function evaluating synthetically the time domain response performance is chosen to optimize the interconnected constraint matrix in the design. The performance indexes of the system are improved. The simulation research is done against a kind of interconnected power system model. Consider a new area subsystem is add to original system on line, the automatic generation control law of the new area is designed by using the proposed method. The simulation results show that the proposed method reaches the selfhealing control request, which the structure of the expansion system is stable. The control performances optimized by genetic algorithm are better than the before, and the effectiveness of this method is proved.
关键词:interconnected power system;expansion;dynamic output feedback;genetic algorithm;LMI
摘要:For a class of six order rigid systems, the necessary and sufficient conditions for the origin to be center are given. And the maximal number of limit cycles bifurcating from the weak focus is proved to be 3. For a class of seven order rigid systems, the necessary and sufficient conditions for the origin to be center are given. And the maximal number of limit cycles bifurcating from the weak focus is proved to be 4.
摘要:Based on El-Nabulsi dynamical model, the Noether symmetries and the conserved quantities for the variational problem of Birkhoffian system from extended exponentially fractional integral are presented and studied. Firstly, the El-Nabulsi-Pfaff-Birkhoff variational problem from extended exponentially fractional integral is presented, then the corresponding El-NabulsiBirkhoff equations are derived. Secondly, the definitions and the criteria of the Noether symmetric transformations and the Noether quasi-symmetric transformations of the system are given, which are based on the invariance of El-Nabulsi-Pfaff action under the infinitesimal transformations of group. Finally, the Noether theorem for the variational problem of Birkhoffian system from extended exponentially fractional integral is established, which reveals the inner relationship between a Noether symmetry and a conserved quantity. An example is given to illustrate the application of the results.
摘要:A method based on the histogram of the sample feature distribution is presented to construct the mass function,for the problem of pattern recognition using the multi-feature fusion. Firstly, the sample feature distribution is established. In the overlapping area of the histogram, the feature is uncertain; while in the nooverlapping area of the histogram the feature is determinate. Then, for a new object, if one of its features falls into the overlapping region of the histogram, the mass function constructed by this feature has a larger uncertainty; if the feature falls into non-overlapping region of the histogram, the mass function constructed by this feature has a greater certainty. The mass functions of different features are fused to get the fusion result. The correct ratio of the irisplant classify experiment is 96.64%, and the result shows that this method is feasible.
关键词:evidence theory;basic probability assignment function;histogram
摘要:The Lanchester competition model has been introduced to study public investment in urban mass transit and the effect function of investment has been defined. Under the conditions of dynamic market share and dynamic market scale, the optimal strategy of public investment between rail-transit and bus transit has been discussed, and thus the optimal allocation proportion of public investment has been derived. Although the preferential development strategy of urban mass transition is the purport of the Twelfth Five-year Plan for public transit in Shanghai, there hasn't been a concrete scheme of investment in public transportation, particularly with regard to the investment scale and the investment allocation between rail transit and bus transit. Through the analysis of the allocation schemes of investment by the government in the rail-transit and bus transit enterprises, the intended target of the development of public transportation is achieved. Meanwhile, the evaluation of the rationality of previous allocation of resources will also help improve the performance of public transport investment in the future.
关键词:Bass diffusion process;Lanchester competition model;effect function of investment;public transit
摘要:Traditional no reference blur image quality assessment methods usually need a pretraining and learning or a reference image constructing procedure, this result in the algorithm with high computation cost. Aiming to this, a simple and effective no reference blur image quality assessment algorithm is proposed based on wavelet high frequency coefficients singular value decomposition. The method is build on the observations that the different wavelet high frequency subbands in the same scale of an image are highly structural correlation, and the degree of correlation would be reduced as the blur distortion deepening. According to this, the new method first makes wavelet transform to the image, then makes singular value decomposition to the high frequency sub-bands to get their structure information. Finally, the angles, which represents the similarity, between different high frequency sub-bands structural vectors are calculated and the sum of angles is used as the last objective assessment index. Experiments results show its good effectiveness and performance on LIVE2, CSIQ and TID2013databases and compared to the traditional noreference methods, the proposed algorithm is more efficient and practical as it does not need to train or create a reference image.
关键词:no-reference image quality assessment;wavelet transform;blur Image;singular value decomposition