Table of Content

    25 July 2016, Volume 55 Issue 4
    WASD neural network activated by bipolar sigmoid functions together with subsequent iterations
    ZHANG Yunong;XIAO Zhengli;DING Sitong;MAO Mingzhi;LIU Jinrong
    2016, 55(4):  1-10. 
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    A weights-and-structure-determination (WASD) algorithm is proposed for the neural network using bipolar sigmoid activation functions together with subsequent iterations, which is the combination of the Levenberg-Marquardt algorithm and the weights-direct-determination method for neural network training. The proposed algorithm, combined with the Neural Network Toolbox of MATLAB software, aims at remedying the common weaknesses of traditional artificial neural networks, such as long-time learning expenditure, difficulty in determining the network structure, and to-be-improved performance of learning and generalization. Meanwhile, the WASD algorithm has good flexibility and operability. Taking data fitting of nonlinear functions for example, numerical experiments and comparison results illustrate the superiority of the WASD algorithm for determining the optimal number and optimal weights of hidden neurons. And the resultant neural network has more excellent performance on learning and generalization.

    The alternating labeling of the graph Fn,4(r1,r2,…,r3n+1)
    WU Yuesheng
    2016, 55(4):  11-14. 
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    For natural numbers n(n≥1), r1,r2,…,r3n+1,  let V(Fn,4)={v1,v2,…,v3n+1}, Fn,4(r1,r2,…,r3n+1)is the new graph that every vertex vi in the V(Fn,4)={v1,v2,…,v3n+1}  is bonding ri hanging edges. The gracefulness of the graph Fn,4(r1,r2,…,r3n+1) is discussed. It is proved that the graph Fn,4(r1,r2,…,r3n+1) is alternating graph.

    The analytic formula of the number of perfect matchings of two types of graphs
    TANG Baoxiang;REN Han
    2016, 55(4):  15-17. 
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    Matching counting theory is an important part of graph theory and also a active research field. It has not only many applications background, and also the source of many important ideas developed during the rapid growth of combinatorics during the last several decades. But the problem of counting the number of perfect matchings for general graphs is NP-hard. By applying differentiation, summation and re-recursion calculation, several counting formulas of the perfect matchings for two specific types of graphs are given. By the method presented in this paper, the number of all perfect matchings of many graphs can be calculated.

    Output feedback control for two dimensional vibration of a flexible marine riser
    PAN Chuan;HOU Chang;WU Yilin
    2016, 55(4):  18-25. 
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    The two dimensional vibration control problem of a flexible marine riser with internal fluid dynamics and the ocean current is considered. The dynamic behavior of the flexible riser is described by two partial differential equations and six ordinary differential equations. To improve the vibration control performance and avoid the control spillover, the Lyapunov's direct method and high-gain observer technique are adopted to develop two output feedback boundary controllers for vibration suppression of the riser system based on its original infinite-dimensional model. With the proposed control, uniform ultimate boundedness under ocean current disturbance and uniform boundedness of the closed-loop state are proved. The simulation results have verified the effectiveness of the designed boundary control scheme.

    Global stability of a HIV-1 epidemic model with time delay and saturation incidence rate
    YANG Junxian;WU Yuancui;YAN Ping
    2016, 55(4):  26-29. 
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    A HIV-1 epidemic model with time delay and saturation incidence rate is proposed. The global stabilities of a disease-free equilibrium E0(T0,0,0) and a positive equilibrium E+(T*,I*,V*) are discussed. By constructing Lyapunov functions and LaSalle's invariant principle, it is shown that if dμ>sγβ, the disease-free equilibrium E0(T0,0,0) is globally asymptotically stable, and if dμ<sγβ, the positive equilibrium E+(T*,I*,V*) is globally asymptotically stable, for all τ≥0. Numerical simulations are carried out to illustrate the theoretical results.

    Real-time object detection with foreground fusion from multiple cameras using homography mapping of polygon vertices
    REN Jie;XU Ming;ZHAO Huimin
    2016, 55(4):  30-38. 
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    Multi-camera and multi-plane foreground fusion approach can relieve the effects of occlusion and improve the accuracy and robustness of moving object detection. The traditional homography mapping is an image-level transformation which projects each pixel in the binary foreground image into a reference view. To avoid perspective openings or holes which are generated during the mapping from the camera view to the top view, the number of the pixels in the homography mapping is decided by the resolution of the top view, which is usually higher than that of the camera view. The slow speed has dissuaded the foreground homography mapping from real-time applications. A foreground polygon approximation method is proposed. After the foreground regions are identified in a camera view, each foreground region is approximated by a polygon and only the vertices of the polygon are projected to the reference view through homography mapping. Then the projected foreground region, which is rebuilt in the reference view, is utilized in real-time moving object detection with multiple cameras. To evaluate the performance, the proposed polygon approximation method has been compared with the contour based method and the bounding-box based method. The experimental results have shown that the proposed algorithm can produce competitive results in comparison with those using foreground bitmap mapping. Considering the differences of moving objects-size, the processing speed is about 12 and 69 times faster than the bitmap mapping method.

    Oblique incidence cnoidal water wave-induced seepage effects on vertical breakwater
    ZHU Menghua;HUANG Hua;ZHAN Jiemin;ZHANG Ao;GUO Lin;CHEN Ruizhi
    2016, 55(4):  39-46. 
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    Based on cnoidal wave theory and expanding Biot consolidation theory, the mathematical solutions to the problems of oblique incidence shallow water wave reflected by vertical breakwater resting on permeable elastic seabed are given, and accordingly the analytical solutions to the shallow wave-induced seepage pressure are derived by applying the eigenfunction expansion approach. Then the wave-induced uplift force and overturning moment caused by the seepage pressure on the bottom of vertical breakwater are accordingly evaluated and compared with horizontal wave force and moment. The evaluating results demonstrate that in certain condition, the wave-induced seepage loads may have same order of magnitude as the direct wave loads. The variation of incident wave angle, sea water and seepage condition, and structure geometry condition may have some influence on wave-induced seepage loads, especially on wave-induced seepage overturning moment. The cnoidal wave-induced seepage loads are obviously larger than those predicted by Airy wave theory for shallow water, it denotes that the cnoidal wave theory can reflect wave nonlinear effects.

    The microscopic mechanism of the shear properties of two dimensional ideal particle
    GUO Hong;CHEN Xi;LI Jun; CHEN Dongliang
    2016, 55(4):  47-52. 
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    By analyzing the micromechanics of the two-dimensional ideal particles (disc) under direct shear test, the movement during the shearing is investigated.  The formula described the maximum shear stress in the regular dense packing condition is established. In addition, following the direct shear simulations of the four samples with different particle size distributions, application of the formula which could predict the maximum shear stress was discussed. The results show that  the maximum shear stress is depending on two parameters namely boundary effect parameter and the non-boundary effect parameters, and these two parameters keep the same under the regular dense packing when the vertical loading is constant. For the general packing, the boundary effect parameters remained unchanged, and the non-boundary effect parameter is linearly decreases with the d10, d30 and d60.

    Noether-Mei symmetry and conserved quantity of Birkhoffian system
    WANG Xueping;ZHANG Yi
    2016, 55(4):  53-55. 
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    The Noether-Mei symmetry and the conserved quantity of a Birkhoffian system are studied. The definition and the criteria of the Noether-Mei symmetry of the system are given. The conditions that the Noether-Mei symmetry leads to the Noether conserved quantity or the Mei conserved quantity and the form of the conserved quantities are obtained. Two theorems for the Noether-Mei symmetry and the conserved quantity are established. At the end, an example is given to illustrate the application of the results.

    Multi-circle-tube frozen wall temperature field development and deviation pipes influence
    CHEN Junhao;XIA Hongbing;LI Dongwei
    2016, 55(4):  56-62. 
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    It is well known that artificial multi-circle-tube freezing method could provide better experiences on shaft excavation in deep stratum. For further researching on evolution of the thermal field, the analogy model simulation was carried on, and the temperature field characteristics in frozen wall without freezing tube deviation were analyzed as well as it in random deviation of freezing tube. Comparing the results, it was concluded that the radius of the circular distribution of freezing tube poses slight effects on the annular expanding velocity of the frozen wall, and freezing tube deviation has minor influences on the temperature distribution of the shaft wall and the effective thickness of the frozen wall as well. It has important impacts on the time of frozen wall circle-crossing in different positions and the average temperature distribution in radial direction. In addition, it could result more enclosed confined water storage within the inner of the frozen wall, thereby increasing the heave force inside the frozen wall with negative effects on the stability of the frozen wall. As a result, the freezing tube deviation should be controlled strictly as drilling freezing holes.

    Performance of crystalline silicon PV modules with different backsheet applied in the humid and hot climate
    ZENG Xiang'an;FENG Jiangtao;JIE Ganxin;FENG Hao;CHEN Xinxin;LI Hui
    2016, 55(4):  63-67. 
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    The polysilicon PV modules with CPE, KPE, TPT and AAA backsheets loaded with fixed resistance were studied for the performance of the long term exposure in the hot and humid climate test site(Qionghai, Hainan).The surface temperature of modules were recorded by the thermocouple sensors for real-time monitoring and the I-V properties of modules were tested by I-V tester after a certain time. The results showed that the maximum power and fill factor degraded remarkably with increasing temperature of PV moudules. Compared with other modules, the module with CPE backsheet had the highest surface temperature, then the most severe degradation of maximum power and fill factor and the bigger increase of series resistance.

    Lead cations adsorption by dentifrice containing nano hydroxyapatite particles with different sizes
    YANG Jianzhen;SHEN Xiaoqing;LIU Chengxia;XU Pingping
    2016, 55(4):  68-74. 
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    Toothpaste with nano HA was conducted according to the adsorption of lead ions in synthetic wastewater. Comparisons were made between distinct particle sizes of nano HA based on the adsorption effect of lead ions. Meanwhile, the stability of adsorption and mechanism of nano HA toothpaste was investigated. The suspensions of nano HA, HA dentifrice and blank dentifrice with different concentrations were prepared.Lead ion solutions with initial concentration of 1.0 mg /L were mixed with these suspensions respectively. Following being kept still for 24 h, 14 d and 28 d, the residual lead ion concentration of the supernatant was measured, the sorption rate and sorption ability was calculated. The result showed that the nano HA and nano HA dentifrice with various particle sizes had strong abilities of absorbing lead ions from simulated waste water, the average adsorption rate was determined to be 95%. The adsorption capacity of nano HA increased with the decrease of particle sizes. The adsorption capacity of nano HA dentifrice was significantly higher than that of the micro HA dentifrice and blank dentifrice. The effects of nano HA dentifrice group on Pb2+ adsorption were relatively stable, of which no desorption were detected subsequently. Both Langmuir and Freundlich equations were sued to simulate the sorption processes of the nano HA and HA dentifrice. The result indicated that the dentifrice containing nano HA could reduce the lead ions effectively,and could be used as an environmental protection absorbent, which is beneficial to giving environmental significance for the daily health caring behavior.

    Synthesis and adsorption properties of composite microsphere with dual-magnetic responses
    CAI Lifeng;WANG Chunli;LIN Wang;WU Dingcai
    2016, 55(4):  75-80. 
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    Seed emulsion polymerization was carried out to fabricate a novel class of thermo-sensitive Fe3O4@poly (N-isopropylacrylamide-co-styrene) composite microspheres (Fe3O4@P(NIPAM-co-St) )The structures of the as-prepared composite microspheres were characterized by TEM, FTIR, DLS, TGA and VSM. UV-Vis was employed to investigate the adsorption and magnetic-induced desorption behaviors using Rhodamine B (RhB) as a model molecule. The results indicated that the composite microspheres possessed a unique multi-core-shell structure. The magnetic nanoparticle content and saturation magnetic induction intensity of microspheres decreased with an increase of the St content during polymerization. RhB adsorption performance was improved when a proper amount of hydrophobic St comonomer was introduced into microspheres. The composite microspheres showed a high RhB adsorption capacity of up to 13.31 mg/g under an acid condition. As compared with the free desorption under room temperature, much more RhB on the composite microspheres could be desorbed under alternating magnetic field. The adsorption capacity of composite microsphere still achieved 8.82 mg/g after five adsorption/desorption cycles, indicating good dual-magnetic responses (magnetic separation and magnetic-induced desorption).

    Visible photocatalytic degradation of rhodamine B by a photo fenton-like system consisting of PW11O39Fe(Ⅲ)(H2O)4-/H2O2
    CHEN Yan;LI Dulei;YANG Jinman;GAO Wenkai;HUA Yingjie;WANG Chongtai
    2016, 55(4):  81-86. 
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    A photo-Fenton-Like system (PW11Fe/H2O2) using Keggin-type Fe(Ⅲ)-substituted〓heteropolyanion PW11O39Fe(Ⅲ)(H2O)4-(PW11Fe) as the visible light activity component was studied, which was employed for the photocatalytic degradation of model pollutant rhodamine B (RhB) under an artificial VIS irradiation. Influences of the H2O2 concentration, the PW11Fe concentration, the initial RhB concentration and the solution pH on the photocatalytic degradation rate of RhB was also examined, together with a discussion on the kinetics of RhB degradation. The results showed that the degradation ratio of 100% was obtained at 60 min for 0.01 mmol·L-1 RhB with the optimum conditions of pH 4.5, 0.6 mmol·L-1 PW11Fe and 4 mmol·L-1 H2O2 under the irradiation of 250 W metal halide lamp. The total organic carbon (TOC) removal was about 48% at 240 min. The hydroxyl radical quenching and electron paramagnetic resonance (EPR) experiments revealed that hydroxyl radicals generated by PW11Fe/H2O2 system under visible light irradiation were the main reactive oxygen species, resulting in the rapid degradation of RhB. The apparent rate constant of RhB degradation was estimated to be (6.2±2) 10-2 mmol·L-1· min-1.

    Stability of efficacy composition content of different thymopentins
    XUE Hongbao;CHANG Hualan;LIANG Lili;ZHANG Hui;MA Tao;JIN Rongfu;ZHANG Chengshan;GONG Wenwu
    2016, 55(4):  87-94. 
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    Reversed phase high performance liquid chromatography was used to analyze three types of the 10 batches thymopentin preparation: water injection, powder injection and solid preparation, and their efficacy assessments were processed through composition content determination. The result indicated that the efficacy composition contents of water and powder injection drugs were higher than that of solid preparation. This could be due to water and powder injection preparation forms were sterile products. The thymopentin composition was not easy to decompose and metamorphic with single matrix components under aseptic conditions. Several factors are not conducive thymopentin solid preparation to stability: solid preparation as entericcoated troche are nonsterile products, in addition, the troche of the corresponding supplementary material composition is complex relatively. The ingredient material make the thymopentin solid preparation composition stable, and the efficacy could be developed. The high value for application could be obtained by improve the bioavailability thymopentin solid preparation.

    Molecular dynamics simulation of infinite dilution diffusion coefficients for several alkanols in H2O
    LI Zhiwei;LAI Shuhui ;GAO Wei;CHEN Liuping
    2016, 55(4):  95-99. 
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    The infinite dilution diffusion coefficients (D12) of some methanol, ethanol, and 1-propanol in water under the condition of 0.1 MPa and 298~318 K were simulated by molecular dynamics (MD) simulation. The microscopic structure and the intermolecular interaction was also analyzed by calculation of the radial distribution function, coordination number (CN) between the center mass of solute and solvent molecules, and the average number of hydrogen bond of this system. The simulated values are in accordance with that of experiment. In addition, the peak height of radial distribution function, coordination number, and average number of hydrogen bond all decrease with the increase of temperature, indicating that the accumulated water molecules around alkanol molecule decrease and the interaction between alkanol and water reduce. These factors jointly enhance diffusion coefficient. In general, this work provides a reliable simulation method for transfer properties of solutes in water. At the same time, the results are helpful for one to deeper understand the relationship between microscopic structures of fluid and its transfer properties.

    The effect of the length of donor homologous arm on the efficiency of ZFN-induced homologous recombination
    NIE Yu;QIAO Yanle;CHEN Yaosheng;HE Zuyong
    2016, 55(4):  100-107. 
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    Zinc finger nuclease (ZFN) is composed of an engineered site-specific Cys2-His2 zinc finger domain and the nonspecific restriction enzyme Fok I cleavage domain, which is able to cut at a specified genomic locus to generate double-strand break (DSB) of DNA. The DSBs induced by ZFN are subsequently repaired through two different DNA repair mechanisms, either non-homologous endjoining (NHEJ) or homology-directed recombination (HDR). NHEJ is prone to introduce sequence insertions or deletions (indels), and can therefore produce frameshifts in open reading frames and gene loss of function. HDR requires a donor template with the sequence similar to the genome to mend a lesion. By introducing a DNA donor with desired modifications, precise genomic modifications can be achieved at a frequency improved 102-104fold as compared to the traditional gene targeting method. Currently, most studies have focused on screening ZFN with higher activity, and improving the delivery efficiency of ZFN and donor into host cells, less studies have investigated the relationship between the homologous arm length with the efficiency of ZFN induced homologous recombination. Here, we constructed a pair of ZFN plasmids targeting to EGFP and verified its cutting activity. Then we designed a series of donors with different lengths of homologous arms. By introducing individual donor with ZFN into CHO cells harboring a frame-shift GFP gene, we measured the homologous recombination efficiencies through the flow cytometric analysis. We found that a 50 bp short homology arm was capable to support ZFN-mediated homologous recombination. Increasing the length of the homologous arms could improve the efficiency of ZFNmediated homologous recombination. A dramatic improvement (104fold higher than traditional method) requires a homology arm longer than 1 000 bp.

    Optimal timing of autophagy occurrence induced by earle's balanced salts solution in DLD-1, HCT-116, A2780, CHO, Hep G2 and SMMC7721 cancer cell lines
    ZHANG Wenliang;ZHANG Mingming;LIU Bin;SHI Hongshun;WANG Haihe
    2016, 55(4):  108-117. 
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    Autophagy has emerged as a key effector in tumorgenesis, but its precise function remains elusive. Autophagy flux is too low to be detected in normal culture conditions. Earle's balanced salts solution (EBSS) is often used to induce autophage with two distinct advantages compared with other inducers: one is only  needed to considerate the induction time, rather than the drug concentration; the other is that it exerts only starvation pressure by specifically simulating amino acids deprivation to cells without other undistinguishable cytotoxicity. Given the tolerance threshold of outside stimulus differs in various types of tumor cells, in this study we carried out the autophage induction experiments with several time points in DLD-1 and HCT-116 colon cancer cell lines, A2780 and CHO ovarian cancer cell lines, Hep G2 and SMMC7721 hepatocellular carcinoma cell lines. Our westernblotting and Immunofluorescence staining results demonstrated that EBSS can efficiently induce autophagy in the assayed cells, precisely with 2 hours treatment in DLD-1, HCT-116, Hep G2 and CHO cells, 4 hours in A2780 and 8 hours in SMMC7721 cells, respectively. Our results provide a reference for autophagy induction with EBSS in cancer cells, and would be useful to shorten the time-consuming optimizing process.

    Comparison of anti-inflammatory effects between Lonicerae Japonicae Flos and Lonicerae Flos using an acute stomatitis model
    LI Panlin;HE Lili;LI Chuyuan;BAI Yang;WANG Deqin;LIAO Yiqiu;LI Peibo;WU Zhong;SU Weiwei
    2016, 55(4):  118-122. 
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    The acute stomatitis model in KB cells induced by cigarette smoke extract (CSE) has been established to study the anti-inflammatory effects between Lonicerae Japonicae Flos (LJF) and Lonicerae Flos (LF),and the protein expression levels of TNF-α, IL-6, IL-8 and IL-10 were detected by Elisa method after treatments of LJF or LF extracts. The results showed that the extracts of LJF or LF could both reduce the protein expression levels of TNF-α, IL-6, IL-8, improve the low expression of IL-10 in a dose dependent manner, suggesting their certain antiinflammatory effects.LF presented significant better antiinflammatory effects than LJF in the regulation of TNF-α, IL-6 and IL-10. These results provided a basis for the rational utilization of LJF and LF herbs.

    The influence of CO2 on relevant indexes of energy substance utilization in the larvae of Stegobium paniceumand Lasioderma serricorne
    CAO Yu;LIU Yan; WANG Lijuan;RAN Guangmei;SHANG Baozhen; LI Can
    2016, 55(4):  123-129. 
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    Energy substances played an important role in adversity resistance of insects. In order to clarify the difference of energy substances utilization rates in the larvae of Stegobium paniceum and Lasioderma serricorneunder CO2 exposure, the contents of polysaccharide, soluble protein and lipid in larvae of these two species were determined after their exposure to CO2 for 2, 4, 6, 8 h under different CO2 concentrations (10%、30%、50%、70% and 90%). In addition, the utilization rates of the energy substances in insects were also determined after they were exposed to the different CO2 concentrations until dead. The results showed that the content of energy substances decreased with increasing CO2 concentration under the same exposure time or extension of exposure time under the same CO2 concentration. The content of energy substances were the lowest in both of the two species after these insects were exposed to 90% CO2 for 8 h, and the content of polysaccharide, soluble protein and lipid in S. paniceum were 13.75, 165.42 and 37.25 μg/insect, respectively, which were 14.87, 176.14 and 38.49 μg/insect in L. serricorne. Both of the two species performed a similar utilization to the three kinds of energy substances after each CO2 exposure until dead, with the order of polysaccharide>lipid>soluble protein, and the utilization rates decreased significantly with the CO2 concentration increase. Furthermore, there was no significant difference in the soluble protein utilization between the two species, but the utilization rates of polysaccharide and lipidin S. paniceum was significantly higher than that of L. serricorne. The results showed that the CO2 concentration had significant influences on the energy substances of polysaccharide, soluble protein and lipid in Stegobium paniceum and Lasioderma serricorne larvae, thus we could use CO2 treatments to affect the physiological index of insects for pest control in the Chinese medicinal materials protection.

    Non-stationary flood frequency analysis of North River and West River Delta with time-varying moments
    LIU Bingjun;QIU Kaihua;LIAO Yeying
    2016, 55(4):  130-135. 
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    The time-varying moment (TVM) was used to analyze the non-stationary flood frequency in the North River and West River Delta and its response to the changing environment using the annual peak discharge records of Makou and Sanshui stations from 1960 to 2009. In comparison with traditional frequency analysis, TVM takes into consideration of varying characteristic parameters of hydrological time series and therefore gives better results reflecting the evolution character on the changing environment. The return period decreases with the appointed design discharges, while the design discharge increases significantly with the appointed return period, which is consistent with the phenomenon of more and more extreme hydrologic events in the North River and West River Delta in recent years.

    Quantitative evaluations of fractional contribution of human activities and climate changes to the streamflow variations across the East River basin
    LAI Tianzeng;ZHANG Qiang;ZHANG Zhenghao;KONG Dongdong
    2016, 55(4):  136-145. 
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    Precipitation, daily temperature and evaporation data from 28 meteorological stations and 4 evaporation stations, and daily streamflow data from 4 hydrological stations during 1959-2000 are analyzed by using the elastic coefficient method and the W-ANN model. Besides, construction of water reservoirs and land use changes are also considered in the analysis to investigate fractional contributions of climate changes and human activities as driving factors to streamflow variations. The results indicate that: ① the change point of the streamflow of the East River Basin occurred in 1972, the streamflow was larger after 1972 than before 1972; ② The increased precipitation and decreased evaporation resulted in the increase of streamflow. The fractional contribution of climate change to the increase of the streamflow is 0.27~0.77; ③ Human activities led to the increase of the streamflow via changes of land use. Meanwhile, the construction of water reservoirs or hydraulic facilities tends to modify the annual distribution of the streamflow significantly. The fractional contribution of human activities to the increase of the streamflow is 0.23~0.73 and the fractional contribution decreases from the upper to the lower East River basin. This research has theoretical and practical contribution to human knowledge of the driving factors behind streamflow variations and also to the scientific water resources management of the East River basin.

    Geochemical and geochronological characteristics of the Fengmu mafic rocks in Hainan and its tectonic implications
    HE Huiying;WANG Yuejun;LIU Huichuan;ZHANG Yuzhi
    2016, 55(4):  146-157. 
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    Hainan Island, tectonically located between the Indochina and the South China Blocks, has undergone multiphased structural overprinting and complex tectonic evolution. Mafic rocks, newly discovered in the Fengmu area, Central Hainan, are coeval with Triassic porphyritic granite and mainly composed of plagioclase, clinopyroxene and hornblende. LA-ICP-MS zircon U-Pb dating results for the representative sample yield the weighted mean 206Pb/238U age of (240.3±2.6) Ma, interpreted as the crystallization age of the mafic rocks. They have SiO2 ranging from 48.99% to 56.00%, K2O between 0.63%~3.94% and Al2O3 between 14.56%~17.77%, and have a K2O/Na2O ratio of 0.58~1.32. These rocks show high REE concentrations with ∑REE=214.7~522.7 μg/g, and (La/Yb)N=11.17~31.10, (Gd/Yb)N=2.00~4.50, δEu=0.74~1.. They are characterized by subparallel right-sloping REE pattern, similar to those of island arc volcanic rocks, and by enrichment in LREEs and LILEs and depletion in HFSEs with significant Nb-Ta and Ti negative anomalies. The εNd(t) values ranges from -1.05 to -2.53. Our data indicate that these rocks originated from the enriched mantle source modified by subduction-related fluid/melt. In combination with other available data, it is proposed that the Fengmu mafic rocks at 240 Ma generated at the post-collision extensional setting of the convergence of the South China with Indochina Block in response to the subduction of the Paleotethyan Ocean.

    Dinosaur eggs found in Pingshan, Shenzhen and their geological significance
    LIU Chunlian;YIN Jian;ZHU Zhaoyu;WU Yueqin;CHE Ping
    2016, 55(4):  158-161. 
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    Dinosaur egg nests and lots of eggshells were found from the Upper Cretaceous red sandstones in Pingshan of Shenzhen for the first time. This paper presents the preliminary research on these dinosaur eggs, including the outcrop section, eggshell microstructure and composition and the taxonomy analysis. Due to the geographic location of the egg nest site, stratigraphic position and eggshell structure, these dinosaur eggs are of geological significance and provide important material for studying the migration, geographic distribution and evolution of dinosaurs and stratigraphic correlation.

    Construction and evaluation of green space ecological network in Guangzhou
    JIANG Simin;ZHANG Qingnian;TAO Huachao
    2016, 55(4):  162-170. 
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    Constructing green space ecological network to link the dispersed important ecological patches is an effective way to use limited ecological land for protection of regional ecological security. The biodiversity-rich habitat patches with the minimum cumulative resistance model was chosen to simulate the potential ecological corridors, establish recommended ecological network, and evaluate their connectivity and land use structure. The results show that the ecological network established in this project is very similar to the structure of the ring network, and can meet the actual circs. The forest park group located in the border region of Baiyun, Tianhe and Huangpu, as the key network node, is an important hub for exchanging landscape material among the north, central, and south of the study area. The northern part of dense forest in Guangzhou has a larger area of ecological patches and smaller resistance of ecological corridor. Due to intense development and construction, the central and southern Guangzhou have smaller areas of ecological patches that are scattered and larger ecological corridor resistance, with the appropriate width of the corridor less than 100 m.