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Table of Content

      
    20 July 2012
    Volume 47 Issue 7
    Articles
    Study on xylem structure and histochemistry in Aquilaria sinensis
    ZHANG Xing-li1,2,3, LIU Yang-yang2,4, CHEN Hong-jiang2,4, XU Yan-hong2, ZHANG Zheng2, YANG Yun2,4, WEI Jian-he 2, 4*, LIU Yu-jun1*
    J4. 2012, 47(7):  1-5. 
    Abstract ( 644 )   PDF (2738KB) ( 1067 )   Save
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     To study the morphological and quantitative characteristics of the xylem and histochemistry of differentaged stems in Aquilaria sinensis, the anatomical structure of the stem was analyzed using the Jeffery method, histochemical staining, and microscopic observation. The results showed that the xylem was composed of 5 parts: pith, included phloem, xylem rays, vessels, and fiber tracheids. A transverse section showed that the included phloem (foraminate type) evenly distributed in the xylem. The xylem rays belonged to heterogeneous Ⅲ. The vessel pores were generally arranged as follows: radial pore clusters (2 to 4), multiple pores, pore chains (5 to 10), or a single pore; vestured pits were alternately arranged in the vessels′ lateral walls. Acclivitous simple vestured pits were present in the lateral walls of the fiber tracheid. Trabeculae were present in the neighboring fiber tracheids of the pith. Embolisms were present in the vessels and the fiber tracheids. Trabeculae and embolisms were firstly observed in A. sinensis. The levels and storage tissues of starch, reducing sugars, and volatile constituents were significantly different in the differentaged xylem. This study provides basic anatomical evidence for agarwood formation.

    Network-based differential analyses of cancer-related and unrelated genes
    NIE Ya-ling1, 2, YU Jing-kai1*
    J4. 2012, 47(7):  6-9. 
    Abstract ( 476 )   PDF (1430KB) ( 1534 )   Save
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    Analyzing differences between cancer-related and unrelated genes based on their topological attributes in the protein-protein interaction (PPI) network. We constructed a comprehensive human PPI network with data collected from multiple PPI databases; obtained a set of known breast cancer genes from the OMIM database; and compared cancer-related and unrelated genes based on their topological attributes in the PPI network. The results obtained as follows: (1) We constructed a comprehensive human PPI network and obtained a known breast cancer gene set; (2) We showed that known cancer genes exhibit significantly different network topologies from random genes in the network. A comprehensive PPI network can help us to differentiate cancer genes from unrelated ones by their distinctive topological attributes, such as node degrees, node betweenness and maximally connected components.

    Effects of multi-component selection on the collapse temperature in freeze-drying formulation
    LI Xiao-shuang, WEI Yu-ping, WANG Qing-qing, LI Chun-long, XU Xia*
    J4. 2012, 47(7):  10-13. 
    Abstract ( 453 )   PDF (1572KB) ( 1320 )   Save
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     Observe the appearance and the collapse of the freezedried products and measure the collapse temperatures (Tc) in the multiple component system containing sucrose, amino acid and/or Pluronic F68. Further determine the factors relating to Tc.The collapse of sucrose solution was observed using freezedrying microscope. Tc was measured for different freeze-drying formulations: (1) sucrose solutions at the concentration of 2.5%, 5% and 7.5%.(2)Binary systems containing 2.5%, 5% or 7.5% sucrose and 10 mmol/L sodium phosphate buffer. (3)Ternary systems composed of 5% sucrose and 0.15% amino acid (Arg, Asp, Glu or Tyr). (4) Quaternary system containing 5% sucrose, Pluronic F68 and 0.15% amino acid.  The results obtained as follows: (1) Tc of sucrose solution increased with the sucrose concentration; (2) Introduction of low concentration of sodium phosphate did not lead to change in Tc (P>0.05); (3) The presence of Tyr caused Tc increase by 7℃ (P<0.05); (4) Addition of Pluronic F68 resulted in a decrease in the Tc values, especially in the system with Tyr (6.0℃) (P>0.05). Tc is dependent on the composition of formulation. Introduction of low concentration of sodium phosphate does not lead to the change in Tc. The presence of Tyr results in significant increase in Tc.

    Deployment and optimization of biomacromolecule molecular dynamics simulation process on hundred trillion times cluster
    PAN Long-qiang1,2, GENG Cun-liang1, MU Yu-guang3, LIU Xin4, HU Yi5, PAN Jing-shan4, ZHOU Ya-bin2, GONG Bin5, WANG Lu-shan1*
    J4. 2012, 47(7):  14-19. 
    Abstract ( 570 )   PDF (1640KB) ( 1345 )   Save
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    As a novel tool to study the functions and properties of biomacromolecules, molecular dynamics has been extensively used to investigate the molecular dynamic behavior of proteins and nucleic acids. However, the time scale range of normal molecular dynamics simulation remains relatively narrow,which cannot reach the valid sampling range of biomacromolecules dynamics behavior recently. Temperature replica exchange molecular dynamics can run multiple independent simulations synchronously and effectively increase the simulating speed. Meanwhile, it requires tens of thousands of cores in aspect of the computing resources, yet the simulation systems of published literatures cannot reach such large scale hitherto. By using the 100T Flops cluster of sunway 4000A in National Supercomputing Center in Jinan, we firstly ran the molecular dynamics of single replica and then ran as many as 128 temperature replicas exchange molecular dynamics to simulate the catalytic domain of exocellulases (about 50000 atoms). We simultaneously used up to 6720 CPU cores in this task, the total computing speed accumulated to 2274ns/d, which offers a new approach to run the molecular dynamics over ten thousand CPU cores.

    Density functional theory investigation of scutellarin
    LIU Xiao-ning, YANG Ying-jie, L Qing-zhang*
    J4. 2012, 47(7):  20-25. 
    Abstract ( 485 )   PDF (1515KB) ( 1232 )   Save
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    Scutellarin had wide physiological activity. In this work, Scutellarin was calculated using the Density Functional Theory(DFT) B3LYP method with 6-311G(d) basis set. The molecular structure, dipole moment, hydrophobic parameter, infrared spectroscopy, phenolic hydroxyl bonds dissociation enthalpy, spin density distribution and the frontier orbitals were analyzed to explain its activity. The result showed that Scutellarin’s antioxidant effect was reflected on its phenolic htdroxyls. The C6 phenolic htdroxyl on the A ring has the highest active, C4’ on the B ring was second and C5 on the A ring was at last. Scutellarin may have good absorption effect in the polar environment. The result provides theoretical guidance for using Scutellarin effectively.

    Theoretical explanation of the anisotropic g factors for Cu2+ center in Cu0.5Zr2(PO4)3crystal
    WEI Wang-he, HOU Chun-ju, LU Min, LIU Wei-qing
    J4. 2012, 47(7):  26-29. 
    Abstract ( 513 )   PDF (985KB) ( 1199 )   Save
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    The anisotropic g factors (gx, gy, gz) for the rhombic Cu2+ center in Nasico type Cu0.5Zr2(PO4)3were theoretically investigated by using the high-order formulas of these parameters for a 3d9 ion in rhombically elongated octahedral. The rhombic field parameters in these formulas were determined from the superposition model and the local geometry for Cu2+ center. The result shows that the planar bond angle is about 10°  smaller  than the ideal 90°  in orthorhombic D2h symmetry for Cu2+ center in crystal and the theoretical g factors based on the above angular are in good agreement with the experimental data.

    Electronic structure and thermodynamic properties of ZrC
    ZHANG Shu-hua1, CHENG Xiao-hong2, LIU Fu-ti2,3*
    J4. 2012, 47(7):  30-33. 
    Abstract ( 593 )   PDF (1837KB) ( 928 )   Save
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    Electronic structure was calculated by the first-principle plane-wave density functional theory pseudo potential method. Lattice constants were obtained by the relationship between energy and volume function of ZrC crystal. Through the quasi-harmonic Debye model, the thermodynamic properties of ZrC was obtained in the temperature range from 0 to 3500K and pressure range from 0 to 200GPa. The thermodynamic properties including the relative volumes, thermal expansion, heat capacities, entropy, Debye temperature and Gruneisen parameter changes with temperature and pressure.

    Study of blanket shape on the granular medium surface
    J4. 2012, 47(7):  34-38. 
    Abstract ( 477 )   PDF (1571KB) ( 1111 )   Save
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     When a big object rolling on the surface of the mountain, the mountain structure may be destroyed. Blanket is a region generated by uplift granules stopped in front of the object. In order to understand this natural phenomenon, an angle adjustable three-dimensional granular medium groove was constructed. The relation of blanket shape which is generated by the spherical objects with the particle′s diameter was established by means of image processing technology. Results show that the blanket shape is a quasi-parabola, and it is related to the particle′s diameter, namely the maximum long and halfwidth of blanket and area increases with both particles′ diameter. It is found that the blanket shape formation has two mechanisms of action, namely sphere and granular medium action mechanism and medium and medium viscous mechanism, and the former is little better than the latter. The blanket shape formation is non-Newtonian fluid in the viscous region.

    Study on the heat transfer in three-layer and one-dimensional thin non-metallic film
    LI Rong1,2
    J4. 2012, 47(7):  39-43. 
    Abstract ( 478 )   PDF (1814KB) ( 1443 )   Save
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    Heat conduction in three-layer and one-dimensional thin non-metallic film under high frequency harmonic thermal boundary condition was solved with Laplace transform from the phonon scatter model. Through the examples, the micro-sale thermal response character in thin non-metallic film was discussed. It was shown that the temperature is dominated by the characteristic parameter E in the different position of the thin film. The fluctuating character becomes more obvious and the maximum thermal response temperature is decreasing and then increasing when E is less than 0.1, and it is only decreasing if E is over 0.1. The thermal response velocity is bigger and the time when the temperature reaches maximum is almost the same. In the rear surface, the response velocity increases when E increases, and the maximum thermal response temperature decreases as increases if E is between 0 and 0.25, and increases if E is over 0.25.

    A method of building smart pervasive personal process service context
    ZHOU Jia-qiang
    J4. 2012, 47(7):  44-49. 
    Abstract ( 402 )   PDF (2301KB) ( 1360 )   Save
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    Context awareness is important in promoting the intelligence of human-computer interaction.  To provide smart process service for individual, a strategy of context awareness for personal requirements in pervasive environment was proposed, and then a smart personal process service system architecture was built, which can constructed personal process service context automatically.  The results of tourism instance show that this method is valid and efficient.

    A SVM parameters selection algorithm based on Fisher criterion
    LIU Biao1,2, CHEN Chun-ping3, FENG Hua-min1,3, LI Yang3
    J4. 2012, 47(7):  50-54. 
    Abstract ( 596 )   PDF (918KB) ( 1335 )   Save
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    SVM (support vector machine) classification performance is mainly influenced by the SVM model selection (including the choice of the kernel function and parameters selected). It is not better to determine the SVM model parameters by the existing methods of SVM model parameter selection. Therefore a SVM parameter selection algorithm is presented based on the Fisher criterion. The selection algorithm makes full use of the samples of linear separability in the classes in the feature space, and combines with the gradient descent algorithm for parameter optimization. It is realized by Matlab. The experimental results show that this parameter selection algorithm not only improves the training performance of SVM, but also greatly reduces the training time through the simulation.

    Impossible differential cryptanalysis of reduced-round MIBS
    DU Cheng-hang1,2, CHEN Jia-zhe1,2
    J4. 2012, 47(7):  55-58. 
    Abstract ( 759 )   PDF (1801KB) ( 1358 )   Save
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    MIBS is suitable for extremely constrained environments, such as RFID tags. Based on the analysis of the flaw in Asli Bay’s work, a new impossible differential cryptanalysis is proposed. The attack of MIBS reduced to 12 rounds needs 259chosen plaintexts and 263encryptions.

    Robust H filter design for discrete-time singular switched systems with uncertainties and time-varying delays
    ZHANG Hua-ping1,2, ZHANG Jian-peng3, MA Shu-ping4, FAN Hong-da1
    J4. 2012, 47(7):  59-69. 
    Abstract ( 461 )   PDF (948KB) ( 1281 )   Save
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    The problem of robust H∞ filter design for discrete-time singular switched systems with parametric uncertainties and time-varying delays is discussed. Based on the restricted system equivalent (r.s.e.) transformation and by introducing new state vectors, the singular filtering error system is transformed into a time-delay standard switched system. The transformed system is then discussed by constructing a novel Lyapunov—Krasovskii functional. A sufficient condition for the filtering error system to be regular, causal and uniformly asymptotically stable and to satisfy H∞ performance for all admissible uncertainties is established in terms of linear matrix inequalities (LMIs), and the corresponding filter design is derived. The obtained results are less conservative. A numerical example is given which illustrates the effectiveness of the new theory.

    The quantitative analysis of the impact of financial news on stock market
    ZHAO Li-li, ZHAO Xi-qian, YANG Juan, WANG Tie-jun, LI Qing*
    J4. 2012, 47(7):  70-75. 
    Abstract ( 1038 )   PDF (1192KB) ( 1372 )   Save
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     Text mining and support vector regression techniques were adopted to quantify the impact of financial news on Chinese stock market. Then  the multiple regression of econometrics was used to analyze how the online financial news affected stock market returns systematically. It focused on the impact intensity and time of online news on the stock market, and its impact on listed firms with different scales. Experimental results show that firms with Shenzhen Stock Exchange are more affected by the Internetbased financial news than those of Shanghai Stock Exchange and firms with smaller size tend to have a stronger impact on the movements of Chinese stock market. Our findings include that Internet-based financial news contains hard-to-quantify information of firms, which investors incorporate into stock prices timely.

    The law of large numbers under subliear expectations and its applications
    LIU Zhi
    J4. 2012, 47(7):  76-80. 
    Abstract ( 649 )   PDF (877KB) ( 1455 )   Save
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    Under the uniformly integrable condition, the law of large numbers under sublinear expectations was obtained, and this result was applied to finance. Specially, this result was applied to g-expectations and some limit properties are obtained.

    Linear formed fractional fuzzy differential equations
    WANG Lei1,2, GUO Si-zong2
    J4. 2012, 47(7):  81-84. 
    Abstract ( 456 )   PDF (861KB) ( 1021 )   Save
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    According to the fuzzy structured element method, the Riemann-Liouville derivative of fuzzyvalued function is defined, and the fractional fuzzy differential equations is studied which is linear formed by symmetrical fuzzy structured element. The existence of a solution is given and the solution is obtained by Mittag—Leffler function. Finally, an illustrative example is provided.

    Globally exponentially attractive set of Yang-Chen system and its applications to chaos control
    JU Pei-jun1, PENG Yan2, ZHANG Wei1, TIAN Li1, LIU Guo-cai1, KONG Xian-ming1
    J4. 2012, 47(7):  85-90. 
    Abstract ( 470 )   PDF (1072KB) ( 975 )   Save
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    By constructing a linear transformation and a family of generalized Lyapunov functions, a new method was proposed to obtain globally exponentially attractive sets of YangChen system. And the explicit estimations of the ultimate bounds were derived. In conclusion, this result was applied to the global exponential stability for the chaos control of the Yang-Chen system, and the control was presented by using a less conservative feedback control law.

    Detection and estimation of partial structural change in a class of panel models
    WANG Xiao-gang1, 2, WANG Li-ming1,3*
    J4. 2012, 47(7):  91-99. 
    Abstract ( 487 )   PDF (1272KB) ( 1311 )   Save
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     A new method for detecting and estimating partial structural change at an unknown common time in random effect panel regression model was considered. And the rate of convergence and asymptotic distribution of structural change estimator was derived. The least squares estimator was constructed as global minimizers of the sum of squared residuals in order to identify structural changes. The structural changes can be well estimated even in the short panel data.  Monte Carlo simulations were carried out to verify the theoretical result numerically. Empirical study with 404 China enterprises which participate in share reform showed that structural change exist or not should be detected firstly, and then data analysis and explanation is meaningful. Bias estimator or spurious regression would appear if neglect to detect structural changes.

    Studies on multi-pulse homoclinic orbits for a class of  six-dimensional nonlinear system
    LI Shuang-bao
    J4. 2012, 47(7):  100-105. 
    Abstract ( 499 )   PDF (1018KB) ( 1432 )   Save
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    The Melnikov method was further extended in the case of resonance and the existence of Shilnikov-type multi-pulse homoclinic orbits was obtained using the theory of geometrical singular perturbation for a class of six-dimensional nonlinear system.

    The globally finite time  output feedback control of  a class of SISO nonlinear systems
    LIU Wan-hai, SHEN Yan-jun*, REN Xin-jun
    J4. 2012, 47(7):  106-116. 
    Abstract ( 538 )   PDF (1381KB) ( 1269 )   Save
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    By using the method of dynamic high gain, homogeneous theory, Lyapunov theory and finite time stable theory, an output feedback controller were designed for a class of SISO nonlinear systems. The output feedback controller consists of linear parts and nonlinear parts. The linear parts can make sure the zero solution of the closed-loop system is globally asymptotically stable and the nonlinear parts can ensure the zero solution of the closed-loop system is locally finite time stable. Final, an example was presented to illustrate the effectiveness of the method.

    Stability analysis of the discrete-time switching Markov jump linear system
    ZHANG Li-yan, XIE Dong-mei
    J4. 2012, 47(7):  117-120. 
    Abstract ( 495 )   PDF (917KB) ( 906 )   Save
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    A class of discrete-time switching Markov jump system whose transitions probability is a piecewise-constant function was proposed. Dwell time method and average dwell time method were used to analyze the second-order moment of the system state. Then the sufficient conditions to guarantee system mean square stable were obtained. Moreover, the results can also be applied to the switched systems with double switching signals. The numerical result shows the validity of the theory.

    A multi-product transport problem with transfer and  sent straight and its genetic algorithm
    MA Yu-hong1,2, SUN Shu-fen2
    J4. 2012, 47(7):  121-126. 
    Abstract ( 555 )   PDF (1237KB) ( 1469 )   Save
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    The multi-product transport problem with multi-manufacturer, multi-sales center and multi-customer was studied. Based on the principle of minimizing total transport cost, a mathematical model of multi-product transport problem with transfer and sent straight was established, and a chromosome encoding/decoding method based priority was given to construct a new genetic algorithm for solving the model. The practical simulation results show that this genetic algorithm can rapidly and effectively solve multiproduct transport problem.