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Table of Content

      
    14 December 2011
    Volume 46 Issue 1
    Articles
    Coherence analysis of magnetoencephalography signals related to self-paced finger press
    HOU Wen-sheng1, ZHANG Yang1, LI Wei-na2, WU Xiao-ying1, WU Guo-cai2, FENG Hua2, ZHENG Xiao-lin1
    J4. 2011, 46(1):  1-5. 
    Abstract ( 804 )   PDF (1506KB) ( 1165 )   Save
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    The present study was aimed at investigating the connection between spatially separated brain regions, as well as the changes of the connection in time and frequency domain. Self-paced finger press related magnetoencephalography signals were recorded and analyzed by means of coherence analysis.And coherence coefficient of two signals corresponding to different cortical areas was calculated. Time frequency analysis was also used to discuss the cortical connection changes co-vary closely with time over the course of motor task in the three frequency band-α(5-15Hz)、β(16-25Hz) and low γ(30-45Hz). The results showed that channels with the most significant coherence relative to the selected reference channel were approximately in the same area, and with the increase of frequency band both the coherence coefficient and the coupled area declined. Moreover, the coherence coefficient changed covaried with time in the three frequency band. Then it is infered that there are different neuronal modulations in the contralateral motor cortex, and this modulation co-varies with time, which consequently reflects the changes of correlation between different brain regions in time and frequency domain.
     

    Studies on variation of sap flow of Robinia pseudoacacia in two microenvironment
    TANG Quan1, CAO Bang-hua1, ZHANG Yu-juan1, QING Yong-jian2, WU Li-yun3
    J4. 2011, 46(1):  6-10. 
    Abstract ( 729 )   PDF (1434KB) ( 1089 )   Save
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    Single Robinia pseudoacacia tree sap flow and its environmental factors were respectively measured by means of TDP (Thermal Dissipation Probe) and Portable-Meteorological Station in a 24-year-old pure forest and its mixed forest (Robinia pseudoacacia and Fraxinus velutina) in Coastal Alkali-saline Soil of the Yellow River Delta. The results showed that diurnal variation of sap flow of mixed forest displayed a narrow-peaked curve and that of pure forest displayed a wide-peaked curve, both peaks were occurred at 10:30 or so, and there were no obvious starting and stopping sign of the sap flow even over night; The peak height of mixed forest was higher than pure forest; The daily average sap flow of mixed forest was 145% of pure stands. Water content of mixed forest Soil surface is more than pure stands, and salt content is less than the soil of pure stands. Multiple regression analysis showed that the important factors effected sap flow of mixed forest were solar radiation, air humidity and the important factors affected pure forest were atmospheric temperature, solar radiation.

    Determination of organochlorine pesticides and polychlorinated biphenyls in wheat by gas chromatography with accelerated solvent extraction and gel permeation chromatography cleanup
    XUE Hai-quan1, CUI Zhao-jie1*, DU Shi-yong2
    J4. 2011, 46(1):  11-15. 
    Abstract ( 1092 )   PDF (1218KB) ( 1320 )   Save
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    A new analytical method was developed for the determination of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in wheat samples. The extraction and purification procedures, accelerated solvent extraction (ASE) and gel permeation chromatography (GPC) cleanup  were  respectively presented by optimizing different extraction conditions and the fraction collection time. The detection conditions could be achieved by gas chromatography with electroncapture detection (GC/ECD). The results showed that the method recovery percentages and relative standard deviations (RSD) were 69.8%~87.4% and 1.48%~11.0% for PCBs, 70.4%~113.9% and 3.54%~17.0% for OCPs. The method detection limits (MDL) ranged in  0.03~0.29μg/kg. This analytical method was applied to exam the wheat samples  collected from Shanghe of Jinan city, Shandong province. The concentrations of these seven kinds of PCBs  ranged in 0~157.9μg/kg, and the concentration of these seven kinds of OCPs 2.38~10.02μg/kg. The method was suitable for batch samples with high accuracy, sensitivity and less pre-treatment time, meanwhile, by which the PCBs and OCPs could  be analyzed simultaneously. Therefore, it is an ideal choice for determining PCBs and OCPs in wheat.

    Synthesis and characterization of tegafur-layered double hydroxides nanohybrids
    ZHANG Shao-jie, XU Jie, LI Yan-hong, HOU Wan-guo*
    J4. 2011, 46(1):  16-19. 
    Abstract ( 709 )   PDF (1150KB) ( 1029 )   Save
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    The intercalation of tegafur into Zn-Al layered double hydroxide (LDHs) with Zn/Al molar ratio of 2.0 was carried out using coprecipitation method to obtain tegafur-LDHs nanohybrids. According to the gallery heights of tegafur-LDHs nanohybrids and sizes of tegafur molecule, a probably morphology of tegafur molecules in the gallery of tegafur-LDHs nanohybrids was suggested,of which the  tegafur molecules were intercalated into the gallery of LDHs with an overlapped bilayer along the long axis vertical-arranged to the LDHs layers. The release kinetics of tegafur from the tegafur-LDHs nanohybrids was respectively investigated in pH=4.8 and 7.2 buffer solutions and pure water (pH=5.65). It was found that the tegafur-LDHs nanohybrids could control the release of tegafur, and the in vitro drug release from the nanohybrids was remarkably lower than that from the corresponding physical mixture, which showed that the drug-nanohybrids could  be considered as a potential drug delivery system. The release rate of tegafur from the tegafur-LDHs nanohybrids at pH=7.2 buffer solution is remarkably lower than that in  pH 4.8 buffer solution, and that at pure water (pH=5.65) is remarkably lower than that in  buffer solutions. In addition, the release processes may fit to the pseudo-second-order release kinetics.

    Robust and non-fragile H control for linear time-varying uncertain periodic singular systems with parameter uncertainty
    FAN Zhong-guang1, 2, LIANG Jia-rong3, XIAO Jian4
    J4. 2011, 46(1):  20-27. 
    Abstract ( 716 )   PDF (388KB) ( 838 )   Save
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    Robust stability analysis of a class of uncertain neutral systems
    JIAO Jian-min
    J4. 2011, 46(1):  28-34. 
    Abstract ( 684 )   PDF (332KB) ( 1116 )   Save
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    Based on the Lyapunov stability theory, by using a new constructed augmented-discretized Lyapunov functional and free-weighting matrix approach, a new delay-dependent criterion for robust stability was derived in terms of linear matrix inequality (LMI). Numerical examples demonstrated that the proposed criterion was effective and less conservative.

    Robust non-fragile Hstate feedback control for  uncertainty discrete singular systems
    SUN Lin, ZHENG Yu, YAO Juan
    J4. 2011, 46(1):  35-41. 
    Abstract ( 739 )   PDF (487KB) ( 994 )   Save
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    Robust non-fragile H state feedback control for uncertainty discrete singular systems was investigates, and the  necessary and sufficient condition for the existence of controller was  obtained. Furthermore, the desired controller was presented via linear matrix inequality. Finally, the numerical simulation illustrated this effectiveness of the proposed method.

    Measurement and analysis of static firction coefficient on granular-solid interface
    PENG Zheng, WANG Lu-zhu, JIANG Yi-min
    J4. 2011, 46(1):  42-45. 
    Abstract ( 689 )   PDF (860KB) ( 1127 )   Save
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    The friction on interface between granular medium and general solid is an important boundary condition, which is often encountered in research of granular physics. Since the value of the friction coefficients are very different in published literatures, a specialized measurement and research is needed. In this experiment,   the coefficient of maximum static friction between the granular matter and different solid surfaces are measured, and the inferface friction follows the fricion law of da Vinci. The measured static friction coefficients of the granular-solid interfaces are about 0.17-0.20, while the value in handbook of material, for solid-solid interface of same materials is about 0.94. These results indicate that the coefficient of friction in material handbook can not be applied to the problem of granular physis directly.

    A nonlinear elastic analysis of stress-relation models for wedge-shaped granular pile
    ZUO Jing, FU Li-ping, JIANG Yi-min, PENG Zheng, LI Xiang-qun, ZHENG He-peng, WANG Lu-zhu
    J4. 2011, 46(1):  46-50. 
    Abstract ( 690 )   PDF (833KB) ( 806 )   Save
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    Stress distribution of static granular pile is yet an unsolved question up to now,for which several stressrelation models have been suggested in physical literature,including the famous fixed principle axe model and recently proposed tangential stress model. To clarify their relationship with theory of granular elasticity,  the approximations of the models as solutions of the elastic equations and the way to improve were analyzed . The results showed that a good agreement between the models and elastic theory could be seen well inside the pile, while remarkable deviation occured as free boundary of pile side However, the deviation could be improved by decreasing strength of tangential stress near the boundary.

    Phase diagrams of random crystal field Blume-Cape model
    ZHU Hai-xia1, YAN Shi-lei2
    J4. 2011, 46(1):  51-55. 
    Abstract ( 731 )   PDF (1017KB) ( 1021 )   Save
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    By using a cutting approximation, the phase diagrams of the spin 1 random crystal field Blume-Capel (BCM) model is investigated for a cubic lattice. We discuss in detail the influence of random crystal field concentration and crystal field ratio on the phase diagram. The effect of four kinds of the random crystal field on the phase diagrams is discussed: distribution of diluted crystal field, distribution of positive and negative symmetry crystal field, distribution of positive and negative non-symmetry crystal field and distribution of random negative crystal field, and phase diagrams are given. Under crystal field dilution condition, the tricritical point (TCP) exists in a range of crystal field concentration, and, phase diagrams show reentrant phenomenon and crystal field degeneration pattern. Choosing crystal field ratio  α=-1.0 and α=-0.4, the range of crystal field concentration existed TCP is extended. Phase diagrams appear positive crystal field distribution. In particular, Choosing α=0.4, TCP exists over all crystal field concentration, reentrant phenomenon and crystal field degeneration pattern disappear, the phase transition lines have no meeting point with crystal axis and D→∞. And, the range of magnetic order phase reduces.

    The matrix elements of Zeeman Hamiltonian in |3PJMJ〉 scheme
    SUN Yun1, TANG Xu-bing1, HUANG Shi-zhong2
    J4. 2011, 46(1):  56-66. 
    Abstract ( 729 )   PDF (550KB) ( 914 )   Save
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    Based on the spherical tensor form of the Zeeman Hamiltonian of multi-electron atom and by using the matrix elements of one-particle and two-particle operators in the Slater scheme, the matrix elements of Zeeman Hamiltonian (including the quadratically field-dependent terms) for |3PJMJ〉 scheme are carried out in virtue of angular momentum coupling theory and irreducible tensor theory. Take 1s4p configuration of helium for example, fine structure splitting on the 43P state of Helium has been calculated and the energy levels are plotted as a function of magnetic field.

    The stationary structure of the thin accretion  disk with anomalous viscosity
    ZHOU Ai-ping, ZANG Yong-li, ZHANG Hua-fu
    J4. 2011, 46(1):  67-70. 
    Abstract ( 707 )   PDF (687KB) ( 806 )   Save
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    Based on the hydrodynamic equations of the accretion disks, the conservation equations of mass, momentum and energy with absence of magnetic field was given. On the basis of the equations obtained, the structure of the inner region of the accretion disks surrounding black hole was calculated by using the new anomalous viscosity. The numerical results showed that the gas motion was not Keplerian in the inner region of the disk. The temperature varied significantly with the accretion rate, the maximal temperature of the accretion disks could reach 3.35×107K in the case of M=10M,M .=100M .E. The distributions of the mass density and the radial velocity were also shown in this paper.

    Cooperative advertising strategy and order policy under retailers’ competition
    LU Yuan-yuan
    J4. 2011, 46(1):  71-78. 
    Abstract ( 657 )   PDF (465KB) ( 1056 )   Save
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    For a supply chain system formed by one manufacturer and a number of competitive multi-retailers, the problems about the optimal brand advertising investment and local advertising allowance of the manufacturer as a leader, and the optimal local advertising investment and ordering policy of numerous competitive retailers as followers were studied when the demand was uncertain. Stackelberg game model about cooperative advertising were given, and the existence of equilibrium solution was proved, then the algorithm for solving optimization model was put forward. Finally, a numerical exemplification was carried out based on one manufacture and two retailers, and influence caused by parameter variances on the optimal strategy was analyzed.

    The normality criteria about f+a(z)(f ′)n
    LIU Shu-kuan
    J4. 2011, 46(1):  79-80. 
    Abstract ( 630 )   PDF (255KB) ( 1092 )   Save
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    Operators with consistency in Fredholm and Weyl′s theorem
    WANG Ji-rong1, CAO Xiao-hong2, LIU Jun-ying2
    J4. 2011, 46(1):  87-91. 
    Abstract ( 697 )   PDF (312KB) ( 878 )   Save
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    A bounded linear operator defined on a Hilbert space a sufficient and necessary condition is established for which Browder’s theorem and Weyl’s theorem hold by means of the new spectrum σ1( · ). Meanwhile,  the relations of Weyl type theorem are studied.

    Empirical likelihood inference for the parameter in linear model with missing covariates
    WANG Xiu-li1, 2, GAI Yu-jie2, LIN Lu2
    J4. 2011, 46(1):  92-96. 
    Abstract ( 702 )   PDF (478KB) ( 1170 )   Save
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    The empirical likelihood inference for the parameter of interest in linear model with missing covariates is considered. Using the inverse probability-weighted method, the estimating function for the unknown parameter is constructed. The empirical log-likelihood ratio based on our estimating function is proved, under some suitable conditions, to be a standard chisquare distribution asymptotically. With this result,  the confidence region for the parameter can be constructed. At last,  our result is further verified through some numerical simulations.

    Influence diagnostics for generalized binomial regression models
    ZHAO Wei-hua1, FENG Yu2, LI Ze-an3
    J4. 2011, 46(1):  97-103. 
    Abstract ( 684 )   PDF (577KB) ( 1250 )   Save
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    The diagnostics and influence analysis methods of the generalized binomial regression model were sudied. The estimation of the parameters and the Score test of the dispersion parameters about the model are given. And the influence analysis were sudied base on the case-deletion model and under three kinds of local influence. Finally, two numerical examples illustrateed the effectiveness of the method.

    The Geom/G/1 queue with second optional service and multiple vacation
    ZHAO Yuan, TIAN Nai-shuo, YUAN Xiao-juan, JIN Xiao-qing, NING Xiao-hu
    J4. 2011, 46(1):  104-108. 
    Abstract ( 670 )   PDF (480KB) ( 750 )   Save
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    By leading into broad sense service time and using the method of imbedded Markov chains, the Geom/G/1 queue with second optional service and multiple vacation was studied. The PGF(probability generating function) of the steady state queue length and waiting time were derived. And then two particular models were given to further verify the correctness of the model. Final, the numerical examples proved that our model could represent some practical problems reasonably.

    On the fluid approximation for GI/G/1 queue with setup times
    YU Jia-shang
    J4. 2011, 46(1):  109-113. 
    Abstract ( 748 )   PDF (329KB) ( 1012 )   Save
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     A GI/G/1 queue with setup times was modelled to describe the automatic repeat request (ARQ) protocol in communication network. First, a functional lower and upper bound for the idle time was constructed, and then the bound relation was used to obtain the diffusion approximations for the queue length, workload and busy time processes.

    The fractal models of real contact area and contact load for  particles surface in PIM
    ZOU Na-na1, ZHENG Zhou-shun1*, BING Lei2,WEN Juan1, WANG Shuang1
    J4. 2011, 46(1):  114-118. 
    Abstract ( 1007 )   PDF (843KB) ( 1047 )   Save
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    The fractal characteristic of powder particle surface in PIM is represented by the Weierstrass-Mandelbrot fractal function. Based on the theory of contact mechanics, the process of elastic-plastic deformation as particles contact is analyzed by means the critical areas of elastic and plastic. The fractal models of real contact area and contact load for particles surface in PIM are calculated, when powder particles are in states of elastic, elastic-plastic and plastic.

    The Fourier spectral approximation for nonlinear SchrÖdinger equation
    LU Yao1, LI De-sheng2, YANG Yang1
    J4. 2011, 46(1):  119-126. 
    Abstract ( 676 )   PDF (480KB) ( 1253 )   Save
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    Fourier seimdiscrete and fully discrete schemes that inherit the conservation properties of differential equation is presented to numerically solve the nolinear SchrÖdinger equation with periodic boundary conditions. The conditions under which the fully discrete form has an unique solution are discussed and analyzied the error estimates. The implement of the fully discrete scheme requires the solution of a nonlinear system of equations at each time step. The theoretical results are corformed by the numberical experiments using the predictor-corrector algorithm.