Table of Content

    25 September 2015, Volume 54 Issue 5
    A New Fixed Point Theorem of Quasi-Contractions on Cone Metric Space
    XU Shaoyuan;MA Chao;ZHOU Zuoling
    2015, 54(5):  1-4. 
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    By replacing Banach spaces by Banach algebras as the underlying spaces of cone metric spaces, the concept of cone metric spaces with Banach algebras has been introduced. And a fixed point theorem of quasi-contractions with the assumption of normality has been proved. By omitting the assumption of normality and utilizing the theory of c-sequence, the existence and uniqueness of the fixed point for the quasi-contractions is obtained in the setting of cone metric spaces with Banach algebras. As a consequence, the corresponding result in the literature is improved and generalized.

    An Energy Efficient Virtual Network Reconfiguration Algorithm
    PENG Limin
    2015, 54(5):  5-10. 
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    Aiming at the problem of energy consumption in the virtual network mapping, according to the characteristics of the virtual network reconfiguration and energy consumption of substrate nodes and links, a reconfiguration optimization model of mapping virtual networks is proposed. By setting resource utilization threshold in the substrate network, virtual nodes that are already mapped onto substrate nodes, which resource utilization is greater than the high threshold or less than low threshold, are remapped onto the substrate nodes consuming smaller energy periodically, the same operation as the virtual links. By using the method of hibernating and waking up substrate nodes and links, the number of active substrate nodes and substrate links in the substrate network are adjusted dynamically. Simulation results show that EEVNR algorithm balances the substrate nodes and links load effectively, improves the acceptance ratio of virtual network requests and reduces the system energy consumption of mapping virtual networks evidently.

    Some Properties of Convex g-Expectations
    JI Ronglin, JIANG Long, SHI Xuejun
    2015, 54(5):  11-14. 
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    Under the basic assumptions on generators,a sandwich theorem for convex g-expectations and concave g-expectations is proven. Furthermore,for some subsets of all convex g-expectations, the existence of their minimal members are proven and  the properties of those minimal members are characterized.

    Bifurcation of Limit Cycles for a Class of Discontinuous Generalized Lienard Differential System
    LI Shimin
    2015, 54(5):  15-18. 
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    Using the first order averaging method for discontinuous differential system, the maximum number of limit cycles which bifurcate from the periodic annulus of the center for a class of generalized Lienard differential system is studied. By piecewise smooth polynomial perturbating, the linear estimation of the maximum number of limit cycles which bifurcate from the periodic annulus of this center is obtained. The result shows that there are more limit cycles which can bifurcate from the discontinuous Lienard differential system than the continuous one.

    The Graceful Labeling of the Graph S(4m+1,4(t+1),4m-1) Based on the Balanced Labeling of the Path P8m+4t+2
    WU Yuesheng
    2015, 54(5):  19-23. 
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    A definition of the graph S(4m+1,4(t+1),4m-1) is given. The gracefulness of the graph S(4m+1,4(t+1),4m-1) is discussed. It is proved that if m≥1,t≥0, the graph  S(4m+1,4(t+1),4m-1) is a graceful graph.Based on the alternating labeling of P8m+4t+2, four algorithms of the graceful labeling of  S(4m+1,4(t+1),4m-1) are given.

    Graceful Labeling of the Corona for Two Kinds of Graceful Graphs
    2015, 54(5):  24-27. 
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    Graceful graph is one of the important research topics in graph theory with wide application and research prospects. But now it is still difficult to study the gracefulness of general graphs in theory. Ma Kejie conjecture is that all the coronas of graceful graph are graceful graphs. This conjecture has not been proved or denied. For any positive integers m and n, the constructor method gives graceful labeling of I(1-Fm,4) and I(K1,1,1,n), thus prove that I(1-Fm,4) and I(K1,1,1,n)are graceful graphs.

    A Frequency Spectrum Equalization Self-Adjusting Iteration Algorithm
    LUO Zhongliang;LAN Yan;CHEN Zhiming
    2015, 54(5):  28-31. 
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    Traditional frequency self-adjusting algorithm calculates the frequency spectrum directly, which will affect the noise extraction of the signal.Logarithm power spectrum is used to guarantee the positive-value characteristic of the power spectrum, and make the smoothing algorithm with forgetting factor easier to implement.To solve the contradiction between convergence speed and convergence precision of the fixed forgetting factor, a self-adjusting method with varied forgetting factor is proposed. The convergence condition is also deduced. The iteration algorithm whose forgetting factor is the exponential mean value of the response spectrum is designed.Simulation results show that the proposed spectrum equalization algorithm reduces the calculation time by 50%, the steadystate error by 90%, comparing to un-optimized algorithm.

    The Accuracy of Complex Pulse Measurement by a Modified Spatial Encoded Arrangement for SPIDER System
    MA Zhilian;XIE Zhipeng;WEN Jinhui;HU Ting
    2015, 54(5):  32-38. 
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    Compared to other SPIDER devices, the modified spatial-encoded-arrangement for SPIDER system (MSEA-SPIDER) are more advantageous for complex pulse measurement. Using two test pulses with different complex features as examples, the affects of the bandwidths and the spectral positions of the two quasi-monochromic auxiliary pulses on the accuracy of characterization of complex pulses are studied by means of numerical simulation. The simulation results show that both the errors of phase reconstruction for these complex pulses increase with the bandwidth enlargement of the auxiliary pulses, but their degrees of error increase are quite different. The error increases less for the complex pulse with multi-high-order dispersions but smooth profiles of spectral intensity and phase, while much larger for the complex pulse with abrupt variations in its spectral intensity and phase. Especially, when one of the frequencies of the auxiliary pulses is set near each spectral position of the abrupt variations in the pulse phase, the error of phase retrieval should be significantly large. Multishearing measurement for the same complex test pulse is helpful to find and remove this kind of error to reach higher accuracy.

    Damage Identification Based on Chaotic ABC Algorithm
    DING Zhenghao;XU Haojie;LIU Jike;LU Zhongrong
    2015, 54(5):  39-42. 
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    Artificial bee colony (ABC) algorithm is an effective approach to solve structural local damage detection. The damage detection in a double-beam system coupled via a set of springs based on a modified artificial bee colony algorithm is discussed. By using the system natural frequencies and modal assurance criteria (MAC), the ABC algorithm is utilized to solve the nonlinear objective function from the coupled double-beam system. To avoid the algorithm trapped local optimize easily, the ABC algorithm is modified by choosing the tournament selection instead of roulette, and chaotic search mechanism is applied to improve algorithm's global search capability. The simulation results shows that the modified ABC algorithm can identify the local damage of the coupled system effective even under measurement noise,better than the original algorithm.

    The Rule Criteria and Pruning Strategy Based on D-FNN Algorithm Research
    ZUO Jun;ZHOU Ling; LI Xiaodong
    2015, 54(5):  43-48. 
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    A new structure for D-FNN and its learning algorithm are put forward. The structure of this D-FNN is based on RBF neural network. In the new algorithm and structure, generation of fuzzy rule is determined by the output error and the effective radius of the accommodate boundary. At the same time, the application of pruning technology makes a simple network structure, fast learning speed and generalization ability for system. The new algorithm is discussed in detail and compared with correlated algorithms. By these technology methods, the unique advantage of D-FNN is found. At last, simulation program for D-FNN are wrote and the concrete cases are run in the program. Simulation results show that the new D-FNN has a compact structure and excellent performance.

    Noether Symmetries for Non-Conservative Lagrange Systems with Time Delay Based on Caputo Fractional Derivative
    JIN Shixin;ZHANG Yi
    2015, 54(5):  49-55. 
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    The Noether symmetries and the conserved quantities of a mechanical system with time delay based on Caputo fractional derivatives are proposed and studied. Firstly, the fractional Lagrange equations with time delay are established. Secondly, based upon the invariance of the fractional Hamilton action with time delay under the group of infinitesimal transformations, the fractional Noether symmetric transformations, the definitions and criteria of the Noether quasi-symmetric transformations and generalized Noether quasi-symmetric transformations with time delay are given. Finally, the relationship between the fractional symmetries and the fractional conserved quantities with time delay are studied. At the end, an example is given to illustrate the application of the results.

    Numerical Simulation Study of Influence of Interface Heterogeneity on Single Fiber Pull-Out Test of Concrete Matrix
    ZENG Xiangrong;ZHANG Yafang;LIU Hao;LIU Feng;CAI Beihai
    2015, 54(5):  56-61. 
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    Numerical model of fiber-concrete matrix had been generated, and the influence of interface heterogeneity on single fiber pull-out test of concrete matrix had been studied. Furthermore, load-displacement curves, acoustic emission(AE) accumulation curves and interface shear stress distribution curves could be obtained and interpreted. The results of this numerical study indicate that change of the interface heterogeneity has great effects on peak load and degradation of the load-displacement curves. In addition, the AE accumulation increases with the interface heterogeneity. The interface shear stress distribution curves show that the shear stress distribution curves tend to be smooth with the increase of the interface heterogeneity.

    Toughening of Polypropylene Random Copolymer by β-Modification
    LI Mei;ZHANG Zishou;TAN Yunhong;DAI Xin;LI Gu;MAI Kancheng
    2015, 54(5):  62-66. 
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    In order to improve the impact strength of polypropylene random copolymer (PPR), the calcium pimelate nucleated PPR, nano-CaCO3 and calcium pimelatesupported CaCO3 filled PPR were prepared.Their mechanical properties, crystallization behavior and the content of β-modification were studied using mechanical testing, differential scanning calorimetry, wide-angle X-ray diffraction and scanning electron microscopy. The effect of calcium pimelate, nanoCaCO3 and calcium pimelate-supported CaCO3 on the impact strength, elongation at break, crystallization temperature and β-modification contents of PPR were investigated. The result indicated that using supported β-nucleating agent was an efficient method to increase the β-modification contents and improve the toughness of PPR.

    The Secondary Metabolites of the Mangrove Endophytic Fungus Fusarium solani 387#
    SONG Shuang;XUE Yanyu; LU Yongjun; LI Jing;LIAO Baoling;LIU Lan
    2015, 54(5):  67-71. 
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    The secondary metabolites of Fusarium solani 387# from the South China Sea were studied. The structures of compounds were analyzed based on physical and chemical properties, and in comparison with the spectroscopic data with literatures published. Nine Fusarbin compounds were isolated from the mangrove endophytic fungus Fusarium solani 387#  from the South China Sea, and their structures were identified as 5 (〖WTBX〗R〖WTBZ〗)deoxyfusarubin〖STHZ〗(1)〖STBZ〗, 5 (〖WTBX〗S〖WTBZ〗)deoxyfusarubin〖STHZ〗(2)〖STBZ〗, 3methyl ether fusarubin〖STHZ〗(3), Fusarubin(4),〖STBZ〗 Anhydrofusarabin〖STHZ〗(5)〖STBZ〗, Anhydro5deoxyfusarubin〖STHZ〗(6)〖STBZ〗, 2acetonyl3methyl7methoxynaphthazarin〖STHZ〗(7)〖STBZ〗, Javanicin〖STHZ〗(8)〖STBZ〗 and 2acetonyl3methyl5 hydrogen7methoxynaphthazarin〖STHZ〗(9)〖STBZ〗. The absolute configurations as well as the existing form of compound 〖STHZ〗1 and 2〖STBZ〗 were determined by the Xray crystallography for the first time.

    Synthesis and Adsorption Property of Magnetic Molecularly Imprinted Polymers for Analysis of 2, 4-Dichlorophenoxyacetic Acid
    XU Li;XU Xiaoyan;XU Zhifeng;HUANG Jianwen
    2015, 54(5):  72-76. 
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    In this work, the magnetic molecularly imprinted polymers (Mag-MIPs) based on Fe3O4 magnetite were prepared using 2, 4-dichlorophenoxyacetic acid (2,4-D) as a template molecule. The morphological and magnetic characteristics of the Mag-MIPs were characterized by transmission electron microscopy (TEM), fourier transform infrared spectrometer (FT-IR), and vibrating sample magnetometry (VSM). The specific adsorption property was studied using binding experiment. The result showed that Mag-MIPs had higher recognition for the template than the nonimprinted polymers (MagNIPs). Moreover, the specific recognition of Mag-MIPs was further investigated using solid phase extraction (SPE) coulped high performance liquid chromatography (HPLC) analysis of the simulation water samples. The maximum recoveries of spiked sample were in range of 91.7%~110.4% with RSD 7.38 (n=3). These results indicate that magMIPs has potential application in separation and analysis of biological and environmental sample.

    Pollution Characteristics and Determinants of Atmospheric Particulate Matter and Its Determinants in Guiyang
    SU Zhihua;WANG Jianhua
    2015, 54(5):  77-84. 
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    The pollution characteristics and determinants of the atmospheric particulates and its determinants in Guiyang were studied through sorting and statistical analysis of the data of PM2.5, PM10 and meteorological series of Guiyang during 2014-2015, together with assessing of their interaction. The result showed that PM2.5 was the main cause of atmospheric particulate matter in Guiyang, which possessed typical winterspring and summerfall seasonal characteristics. While the average of daily concentration of PM2.5 was 28.79 μg·m-3 in summer, which was fluctuated between 13 to 68μg·m-3. It was increased to 60.64 μg·m-3 in winter, which ranged from 15 to 127 μg·m-3. According to the ambient air quality standard (GB3095-2012), the over standard rate of PM2.5 in spring, summer, fall and winter was 4.4%, 0, 5.5% and 5.5%, respectively. The daily distribution of PM2.5 and PM10 demonstrated a “twin peaks”, the first one of which occurred at 10:00 - 13:00, and it came earliest in summer while latest in winter the second peak occurred at 20:00 - 23:00, the first one of which came earliest in spring while latest in summer. This difference was mainly resulted from the change of season solar radiation and human daily routine. The spatial distribution of PM2.5 showed roughly gradual reduction from urban to rural, the average of which was ordered as Shihuanbaozhan > Yejinting > Huaxi district > Xiaohe district > Hongbianmen > Maanshan > Wudang district > Tongmuling in winter, while the order was Hongbianmen > Yejinting > Xiaohe district > Shihuanbaozhan > Huaxi district > Wudang district > Maanshan > Tongmuling while in summer. Meteorological conditions played a dominant role in atmospheric particulate matter pollution, which was followed by human activities and the local geographical environment.

    The Fermentation Culture of VOCs Solubilization Microorganisms and Its Solubilization
    WANG Guohui, XU Yanan
    2015, 54(5):  85-89. 
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    To improve the water-solubility and biodegradability of VOCs, VOCs solubilization microorganisms were domesticated to make its produce biosurfactant to make VOC solubilize. Benzene and toluene were selected as representative composition,such as solubilization activity and emulsifying rate as index, the fermentation conditions, production regularity and solubilization effect of microorganisms of VOCs solubilization etc were studied. The result showed that the solubilization microorganisms that produce BST were successfully domesticated. The optimum fermentation conditions for the production of BST was that the best carbon source concentration was 1.0 g/L and the optimal initial pH value was in the range of 6.95~7.05 and the optimum temperature range was in the range of 26~32 ℃. The solubilization bacteria had an obvious regularity for production of BST. The BST continue to increased rapidly during the fermentation of 0~36 h, and arrived at a maximum yield at 36 h. The fermentation liquid had good effect on the solubilization of benzene and xylene. The fermentation liquid had good effect on the solubilization of benzene and xylene. They were 2.7 times and 30 times of the pure medium, respectively. The emulsion droplets formed by benzene and BST were as an oil in water and it is soluble in water. This was more favorable for the biodegradation of VOCs. The bacteria producing BST were mostly gram negative bacilli. The BST was initially identified as a polysaccharide. The content of BST in the fermentation broth was about 60 g/L.

    Simplified Calculation Model of Non-Point Source Pollution Removal Efficiency by Ecological Embankment
    YANG Xing;WANG Wei
    2015, 54(5):  90-95. 
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    Quantitative study of non-point source pollution removal efficiency is of significance in effective management of ecological embankment construction. Therefore, this work put forward a new concept of pollution removal efficiency of ecological embankment and the simplified calculation model. Meanwhile, several empirical formulas of key variables in this model were deduced based on the rainfall simulation tests under different ground cover in Changshu City, including pollutant concentrations in runoff water, sediment concentrations in runoff water and pollutant mass concentrations of sediment in runoff water. As one case study for the ecological embankment with a gradient and subsurface treatment system used for Jinjingtang River in Changshu City, the results showed the comprehensive pollution removal efficiency could reach 75.4%, which was in good agreement with experimental data. As a kind of quantitative analysis method of environmental benefits of ecological embankment projects, the establishment of the model had obvious engineering significance.

    Condition Optimization of PDGFR-β/Fc Transient Expression in HEK293F Cells
    HONG Po;YUAN Fengmei;HUANG Jiahui;LIU Dongchen;ZHANG Tu;XIE Qiuling
    2015, 54(5):  96-101. 
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    To optimize the conditions for transient transfection in HEK293F cells and improve the production of PDGFR-β, DNA(pXLG-PDGFR-β)and PEI were separately diluted in ultra-pure water, mixed together, and incubated at room temperature. The PEIDNA complex was then added to the cells, and the culture was incubated at 37 ℃with 6% CO2 with agitation at 180 r/min, then incubated for 7 days. The PDGFR-β/Fc concentration in the culture medium was determined by sandwich ELISA.The conditions including cell density, DNA concentration and ratio of DNA to PEI, as well as other effectors such as adding of VPA and peptone were optimized. The results showed that transient gene expression yields of PDGFR-β/Fc can be maximized under following conditions:4×106 cells/mL, 2.0 μg/106cells DNA, 1∶2 ratio of DNA and PEI and polymerize 5 minutes. The productivity can be further increased with adding of 3 mmol/L VPA, glucose and 1 g/L TN1. The experiment showed that when the conditions for transient transfection of HEK293F cells were optimized, the PDGFR-β/Fc yields up to 55 mg/L were achieved at the conditions, which laid a foundation of PDGFR-β/Fc expression for larger scales transfection in HEK293F cells.

    Genetic Diversity of Mitochondrial Cyt b Sequences in Pelteobagrus fulvidraco from the Pearl River
    ZHANG Heqian;YANG Zituo;LI Guifeng;XIAO Shibin;SUN Jijia;YANG Huirong;ZHAO Huihong;XIE Tanghui;HAN Xingpeng;LIU Li
    2015, 54(5):  102-108. 
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    The mitochondrial DNA cytochrome b (Cyt b) gene segments of 190 yellow catfishes (Pelteobagrus fulvidraco) from five river sections of Pearl river were amplified by PCR technique and sequenced.The complete sequence of the mitochondrial(mt) Cyt b gene of Pelteobagrus fulvidraco was 1,109bp in length. Sequence analysis indicated that there are 43 haplotypes in 190 individuals. The global haplotype diversity (Hd) and nucleotide diversity (Pi) was 0.848 57 and 0.048 17, respectively, indicating a pattern of high haplotype with low nucleotide diversity in the whole population, which indicated that the genetic diversity was a medium level. Sequence alignment performed by Clustal-X 1.81 and MEGA 5.0 softwares showed that AT content (55.1%) was significantly higher than GC content (44.8%) in these samples, and the base distribution was uniform.The genetic differentiation between Duyun and Zuojiang populations was the largest (Fst=0.414 30) based on the molecular phylogenetic tree constructed by maximum likelihood method. The analysis of molecular variance (AMOVA) showed that the genetic variation was 75.23% merely presenting within populations rather than between populations,implying that geographical factors caused certain effects on genetic differentiation of Pelteobagrus fulvidraco. Results of neutral test showed that expansion was not happened among these five populations, therefore their population structures and quantities were relatively stable.

    A Stochastic Model on DNA Double Strand Breaks Repair
    SUN Tingzhe;CUI Jun
    2015, 54(5):  109-114. 
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    DNA double strand breaks (DSBs) pose serious threat to life. Efficient repair of DSBs is crucial for maintaining genomic integrity. Dynamic investigations of DSB repair have received intensive attention. However, previous models do not take into account the relation between extrinsic and intrinsic DNA damage. Therefore, a refined Monte Carlo model was constructed by considering spontaneous DNA damage and setting a threshold for cell cycle reentry. The refined model can better describe the dynamic DSB repair under stressed conditions. Extrinsic DSBs induced by irradiation were first fixed. When the level of damage falls below the threshold, intrinsic DNA damage will then emerge and both the extrinsic and intrinsic DSBs will possibly be simultaneously repaired during a specific period. The current model integrates both extrinsic and intrinsic DNA damage and sets a fertile ground for other models with DNA damage repair process.

    Screening and Identification of Two Cold-Adapted Cellulase-Decomposing Fungal Isolates Collected in Changbai Mountain Area and Optimization of Their Enzyme-Producing Conditions
    GOU Changlong;WANG Yuqiong;WANG Wei;ZHAO Hanxu;LOU Yujie;GAO Yunhang1
    2015, 54(5):  115-121. 
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    In order to screen the efficient cold-adapted cellulose-decomposing strains and optimize conditions for maximum production of enzyme activity, in this study, we isolated the cold-adapted cellulose-decomposing strains with congo red method and flask fermentation from cattle manure and the soil of mountain. The strains were identified by morphological observation and molecular biology identification, and their fermentation condition were also optimized. The result showed that their FPA were (11.23±0.39) U/mL, (5.59±0.36) U/mL, and the strain FF2-2 and F-3I were respectively identified as Aureobasidium pullulans and Aspergillus versicolor. The optimum carbon and nitrogen source of two strains were 0.5 % wheat bran, 0.5 % starch, and 1 % beef extract and ammonium sulfate mixture, 1 % beef extract, respectively. The optimum pH were 7.0 and 6.0, respectively. The optimum fermentation temperature for both strains was 23 ℃, and the optimum fermentation time was 3 d, 5 d respectively. The FPAs of strain FF2-2 and F-3I increased 2.6 and 5.6 times respectively after optimization.

    Flood Risk Zoning Model Based on Ant-Miner and Its Application
    LAI Chengguang;WANG Zhaoli;CHEN Xiaohong; HUANG Ruizhen; LIAO Weilin;WU Xushu
    2015, 54(5):  122-129. 
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    Using Ant Colony Optimization (ACO) to mine rules is a research hotspot nowadays. This paper proposed a new zoning model of flood risk based on ant colony rule mining algorithm (Ant-Miner) to solve the non-linear relationship between index and flood risk grade. The model was used in the Beijiang River basin with the support of GIS technique. The assessment results show that ① 15 simple rules expressed in the form of conditional statement were mined by the AntMiner model. The rules are appropriate for the study areas and can be easily used for generating a zoning map of flood disaster risk. ② The test accuracy is 95.1% in the Ant-Miner model , 92.9% in BP neural network model, indicating that the discriminative capability and flood risk zoning applicability of the former is stronger than the latter. ③ The high risk areas identified by Ant-Miner are mainly located in the regions with large precipitation, flat and low-lying terrain and dense population and property. These areas match well with the submerged areas of historical flood disasters, indicating that the AntMiner model is reasonable and practicable and can provide a new method for flood risk assessment.

    Copula Function-Based Flood Coincidence Probability Analysis for Mainstream and Tributary of the Hanjiang River Basin
    GUAN Shuai;LIN Yingyan;ZHA Xini;DING Bo;TAO Nan;LIU Zufa
    2015, 54(5):  130-137. 
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    The Hanjiang river has been played an important role in economic and social development in Guangdong Province. It is quite necessary to find out the characteristics, occurrences and the dynamic rule of flood along this river for flood control and protection. In this paper, daily streamflow data from three hydrological stations during 1959-2000 were analyzed using the copula function to investigate the probability behavior of the flood coincidence in the Hanjiang river basin. The flood characteristics were defined as annual maximum daily flow,which were analyzed through the joint return periods,the coincidence risk of flood magnitudes and conditional probability. Obtained results showed: ① during the same return period,the coincidence risk of flood magnitudes of Chaoan and Hengshan stations was bigger than Chaoan and Xikou stations,and that of Hengshan and Xikou is the smallest. ② the flood of the Meijiang accounted for a larger proportion in Chaoan station than in the Tingjiang. ③ based on joint distribution of the three stations,diverse streamflow combination could be obtained under certain joint return periods and current return periods, as well as the probabilities of any streamflow combination.

    Response Relation between Precipitation Heterogeneity and Climate Change in Guangdong
    LIU Yonglin;YAN Junping;CEN Minyi
    2015, 54(5):  138-146. 
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    The spatial and temporal inhomogeneity of precipitation is the main cause of drought and flood disasters. Analyzing the spatial and temporal homogeneity of precipitation can provide scientific basis for the flood control and drought relief work. Based on observed precipitation data during 1960-2013 in Guangdong Province, the precipitation concentration degree (PCD) and precipitation concentration period (PCP) were computed and the temporal and spatial variations of precipitation in Guangdong in response to climate change were analyzed for exploring the response relation between the homogeneity of precipitation and abrupt change of temperature. Results showed that: ① The climate in Guangdong was warm and wet during 1960-2013, but became cold and dry gradually after the temperature abrupt change. ② The seasonal precipitation had a good response relationship with the PCD and the PCP. ③ The precipitation was relatively homogeneous but with large varied amplitude, and the PCP arrived earlier. After the abrupt change of temperature, precipitation became more concentrated and concentration period delayed but precipitation tended to be decentralized and concentration period was ahead of time, and the volatility of the PCD and PCP tended to weaken. ④ There were some correlations among air temperature, precipitation, the PCD and the PCP in Guangdong, which was different with northern China. ⑤ After the abrupt change of temperature, precipitation of most areas became more concentrated and concentration period arrived earlier, and all maintained a certain latitudinal variation. This indicated that precipitation uniformity of space-time in Guangdong has a certain response relationship with climate change.

    Astronomical Cyclostratigraphy Study of Quaternary Activities in Northern Segment of the Shunyi Fault, Beijing
    ZHANG Lei;HE Fubing;BAI Lingyan;WU Huaichun;XU Xiwei;CAI Xiangmin;WANG Jimin;SUN Yonghua;LIU Yu;FANG Tongming
    2015, 54(5):  147-154. 
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    Gravity exploration, shallow seismic investigation and high density resistivity measurement were applied to study Sunyi fault in Beijing, and the data in astronomical cyclostratigraphy, magnetic susceptibility and paleomagnetic chronology from a series of drilling cores were used to infer sporadically activities of the fault's northern segment since Quaternary. The astronomical time scales of the footwall and hanging wall of the Shunyi fault were established respectively to constrain the stratigraphic age of two walls. Its activity characteristics since the Quaternary were revealed through comparison with the thickness of strata and differences of deposition rate. The Shunyi fault showed hallmark of intermittency. Seven intensive phases (~2.5 Ma, ~2.3 Ma, ~2.0 Ma, 1.6~1.8 Ma, 1.2~1.3Ma, ~0.5 Ma and ~0.3 Ma) and one sub-intensive phase (~0.9Ma) can be distinguished, and the rest time is considered to be relatively quiet period. Furthermore, Shunyi fault acted intensively in the early and middle Early Pleistocene (earlier than ~ 1.1Ma) being featured by sink-slip-dominated activity, and became weak profoundly since the late Early Pleistocene (after ~ 1.1Ma) with a feature of creep-dominated activity.

    Numerical Analysis of Reclaimed Foundation Consolidation and Settlement and Back-Analysis of the Soil Parameters
    YANG Yongqiang;XU Chao;YANG Yang
    2015, 54(5):  155-160. 
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    Considering the actual conditions of the road engineering in Baosteel tidal-flat enclosure region,the finite element software Plaxis is carried out to simulate the construction process of the PVDs with preloading. And consolidation and settlement characteristics of the large-area reclaimed soft soil foundations are analyzed from a numerical perspective. A comparative analysis of post-construction settlement models is made to evaluate their effects. Combining the specification with one-dimensional consolidation theory, a back-analysis of the soil parameters is performed. The results show that the principal settlement occurs in the preloading period. Asaoka prediction model has the highest accuracy in the site. The back analysis shows that the smaller compression modulus and consolidation coefficient of the soil due to structural disturbance are the reasons of higher theoretical calculation value of subsidence and “fast begin to slow after” of the numerical simulation.