Loading...

Table of Content

      
    16 March 2011
    Volume 46 Issue 3
    Articles
    Allelopathic effects of three submerged macrophytes in the Nansi Lake on Microcystis aeruginosa
    JU Ying-lin, LI Xiao-ming*
    J4. 2011, 46(3):  1-8. 
    Abstract ( 677 )   PDF (2716KB) ( 919 )   Save
    Related Articles | Metrics

    Allelopathy is an important trait in competition between macrophytes and phytoplankton in freshwater ecosystems. Allelopathic effects of submerged macrophytes such as P. crispus, P. lucens, and C. demersum on Microcystis aeruginosa were assessed using co-culture experiments under controlled laboratory conditions. Excluding the influence of nutrient and light intensity condition, the results showed that all three macrophytes had significant allelopathic effects on the growth of M. aeruginosa, and the effects depended on initial algae cell density, the species and biomass of the macrophyte. The growth of M. aeruginosa was significantly inhibited by 10g/L and 5g/L of P. crispus at low initial cell density. At high initial cell density 10g/L P. crispus showed a more inhibitory effect on M. aeruginosa than 5g/L P. crispus. The allelopathic effects of 7g/L and 4g/L P. lucens on M. aeruginosa at two initial cell densities were very significant. Both 7g/L and 4g/L C. demersum had significant growth inhibition on M.aeruginosa at low initial cell density, while less effects were observed at high initial cell density. The allelopathic effects of the three submerged macrophytes increased as P. lucens>P. crispus>C. demersum. In an experiment of the three submerged macrophytes culture filtrates, culture water showed stimulatory growth effects on M. aeruginosa.

    Study on the synthesis of Cefuroxime acid with a new phosphoryl active ester
    REN Hui-xue1,2, YING Han-jie2, LIU Chang1, JIA Xiang-feng1, YANG Yan-zhao3
    J4. 2011, 46(3):  9-12. 
    Abstract ( 785 )   PDF (874KB) ( 710 )   Save
    Related Articles | Metrics

    An improved synthesis of cefuroxime acid was presented. High activity with the phosphoryl new active ester of O, O-diethyl phosphorothioic (Z)-2-furyl-2-methoxyimino acetic anhydride (SMIF-DP)replaced the original electropHilic reagents. The cefuroxime acid synthesis route in the 7-bit aminoacylation reaction was improved. The synthetic routes are simplified in the hydrolysis reaction step and complex reaction step. The intermediates are not isolated in the synthetic routes. The one-pot method synthesized 3-decarbamoyl-cefuroxime (DCCF). The total yield of the Cefuroxime acid was 67.7%.

    Preparation and luminescence properties of CePO4: Dy3+ micro-nanofibers
    GENG Jia-qiang, LI Zhen, TIAN Long, LIU Wei*
    J4. 2011, 46(3):  13-17. 
    Abstract ( 680 )   PDF (972KB) ( 741 )   Save
    Related Articles | Metrics

    One-dimensional CePO4 micro-nanofibers doped with Dy3+ were prepared by using electrospinning technique and high-temperature calcinations. Their structures and optical properties were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA) and photoluminescence (PL) spectra. SEM images indicated that the diameters of fibers were reduced to 150nm when the samples were calcined at 1100℃.  XRD results showed that the crystallinity of CePO4: Dy3+ micro-nanofibres become better with increased calcination temperature and the micro-nanocrystals are the monoclinic phase. The results of FTIR agreed well with the results of XRD. The PL spectra showed considerable enhancement of photoluminescence, especially the emission spectra ofCePO4: Dy3+, which exhibited the characteristic emission of Dy3+ in 4F9/2-6H15/2and4F9/2-6H13/2 transitions and showed that the emission intensities increase with the concentration of Dy3+ increasing in the range of zero to 5.0 %.

    Study of the effects on synthesis Mg-Al-hydrotalcite-like compounds
    WANG Dong-qing, LI Li-fang*, WANG Jian-wei
    J4. 2011, 46(3):  18-22. 
    Abstract ( 719 )   PDF (598KB) ( 606 )   Save
    Related Articles | Metrics

    The size and size distribution will be affected by many factors in the process to synthesize Mg-Al-HTlc (hydrotalcite-like compounds, HTlc) nanoparticles using the mixed co-precipitation method. Orthogonal design was used in this study to synthesize Mg-Al-HTlc nanoparticles and to estimate the factors (such as peptizing time, peptizing temperature, aging time and alkali dosage) effect on the unit cell parameters, size and size distribution in the monodispersed Mg-Al-HTlc nanopartical preparation process. The result showed that the order of factors influencing HTlc mean size was: peptizing temperature> aging time> peptizing time> alkali dosage. The order of factors influencing HTlc size distribution was: alkali dosage> peptizing temperature> aging time> peptizing time. The optimal condition for preparing monodispersed HTlc was: peptizing time 48h, peptizing temperature 100℃, and alkali dosage nNH3·H2O/(2n(Mg2+ )+3n(Al3+ ))=1, aging time 45min.

    Study of the elastic and thermodynamic properties of CaF2
    ZHANG Shu-hua1, LIU Fu-ti2, CHENG Xiao-hong2
    J4. 2011, 46(3):  23-25. 
    Abstract ( 622 )   PDF (464KB) ( 660 )   Save
    Related Articles | Metrics

    Through the first-principles plane-wave ultrsoft pseudopotential method of density functional theory, elastic and thermodynamic properties of CaF2 were studied based on the optimized structure. The result of calculations obtained was: lattice parameter was 0.5480nm; bulk modulus  is  C11=154.4GPa, C12=38.2GPa, C44=29.9GPa, bulk modulus B0 was 76.9GPa, and the Debye temperature was 489.6K according to the Debye mode approximation and the elastic constants. The heat capacity was close to the Dulong-Peti limit at the high temperature.

    A construction of perfect nonlinear functions
    GUO Fei-wang, ZHANG Xi-yong, HAN Wen-bao
    J4. 2011, 46(3):  26-30. 
    Abstract ( 688 )   PDF (318KB) ( 469 )   Save
    Related Articles | Metrics

     Perfect nonlinear functions are widely used in cryptography and algebra combinatorics. By using two known perfect nonlinear functions, a quadratic perfect nonlinear function over finite fields of odd characteristic was constructed based on determining the root of a linearized function.This quadratic function was proved to be inequivalent to x2, and then an example was used to analyzed its inequivalence to xps+1.

    Research of a frequent itemsets mining algorithm based on vector
    ZHANG Wen-dong1, YIN Jin-huan1, JIA Xiao-fei2, HUANG Chao1, YUAN Yan-mei1
    J4. 2011, 46(3):  31-34. 
    Abstract ( 640 )   PDF (645KB) ( 387 )   Save
    Related Articles | Metrics

    To solve the problem that a large number of candidate sets will be generated when an apriori algorithm is used to scan the transaction database many times to look for frequent itemsets, a frequent itemsets mining algorithm is presented based on the combination of vector and array, which can scan the transaction database only once, avoid pattern matching and reduce the generation of worthless candidate sets. In addition, by comparison with the existing algorithms, this algorithm is verified with a high efficiency of mining. And the more items in the database the more effective it is.

    A new type of knowledge systems
    CHEN Jin-kun, LI Jin-jin
    J4. 2011, 46(3):  41-45. 
    Abstract ( 605 )   PDF (314KB) ( 335 )   Save
    Related Articles | Metrics

    The relations between classical knowledge systems and classical exact knowledge systems are further discussed. Some properties of this new type of knowledge systems are presented.

    Dynamic pricing model of the reload stock option with two barriers under Knightian uncertainty
    — the method of option pricing based on the solution of BSDE
    ZHANG Hui1, 2, MENG Wen-yu1, LAI Xiang3
    J4. 2011, 46(3):  52-57. 
    Abstract ( 751 )   PDF (933KB) ( 594 )   Save
    Related Articles | Metrics

     The financial market with Knightian uncertainty is studied. Using the solution of BSDE and the method of time-risk discount, the dynamic pricing model of the reload stock option with two barriers is proposed. Also, the explicit solution of the model is derived. And obtaining the dynamic pricing interval of the reload stock option with two barriers is in accordance with Epstein′s conclusion. Finally, a numerical analysis is applied to depict the important impacts of the investors′ subjective sentimens to Knightian uncertainty and the up and down barrier prices on the pricing of the reload stock option with two barriers.

    Ruin probability in an interfered multi-type risk model of a variable ruin limit
    YU Wen-guang1, HUANG Yu-juan2
    J4. 2011, 46(3):  58-62. 
    Abstract ( 635 )   PDF (331KB) ( 315 )   Save
    Related Articles | Metrics

    In recent years, the limit of ruin has been set as 0 in much literature when studying ruin probability in risk models, while, in practical insurance businesses, the insurance company confronts the ruin issue when its surplus process is lower than a certain limit. In view of this problem, the probabilities of ruin in an interfered multitype risk model are investigated on the assumption that the limit of ruin is variabie and obtain the inequality of the probability of ruin and accurate expression of the ruin probability. In addition adjustment coefficient equations are established and the upper bond and lower bond of the adjustment coefficient are estimated on the assumption that the limit of ruin is especial functions.

    On a correlated discrete risk model with constant dividend barrier
    GAO Shan 1,2, LIU Zai-ming2*
    J4. 2011, 46(3):  63-68. 
    Abstract ( 675 )   PDF (575KB) ( 471 )   Save
    Related Articles | Metrics

    A compound binomial risk model with constant dividend barrier was considered. Two types of individual claims, main claims and by-claims, were defined. By introducing an auxiliary risk model, a system of difference equations with boundary conditions for the expected present value of dividend payments due until ruin was  derived and solved. Numerical results were given for two special claim-size distributions.

    The algebraic properties of internal P-sets
    XIE Wei-qi1,2, LIU Dao-guang1, ZHANG Li2
    J4. 2011, 46(3):  69-72. 
    Abstract ( 723 )   PDF (343KB) ( 458 )   Save
    Related Articles | Metrics

    Using P-sets theory, the dependence relation and measurement of P-sets are given. Based on the dependence relation, internal P-sets  is composed of a lattice. The related characteristics of internal P-sets are given based on the lattice theory.

    Structure of Fuzzy(P)filters on residuated lattices
    MA Li-na1, LIU Shuo2*, WANG Guo-jun1
    J4. 2011, 46(3):  73-77. 
    Abstract ( 584 )   PDF (309KB) ( 587 )   Save
    Related Articles | Metrics
    On t-ordered semigroups
    TIAN Hong-yan, XU Xin-zhai*, MA Jing
    J4. 2011, 46(3):  78-79. 
    Abstract ( 606 )   PDF (234KB) ( 363 )   Save
    Related Articles | Metrics

    t-Ordered semigroups are investigated.  It is proved that semigroups having ideal extension property and regular ordered semigroups are both t-ordered semigroups.

    The existence of non-constant positive steady state of an epidemic model for pest control
    DONG Chun-yan, FU Sheng-mao
    J4. 2011, 46(3):  80-88. 
    Abstract ( 704 )   PDF (389KB) ( 314 )   Save
    Related Articles | Metrics

    An epidemic model for pest control is studied in this paper. The global stability of a unique positive constant steady state for the reaction-diffusion system is analyzed, and then a prior upper and lower bounds for all possible positive steady state are established. Finally, the formation of a stationary pattern for a cross-diffusion system is proved.

    The existence of solution for a doubly nonlinear p-Laplacian equation
    LI Yong-jun
    J4. 2011, 46(3):  89-93. 
    Abstract ( 723 )   PDF (312KB) ( 300 )   Save
    Related Articles | Metrics

    A doubly nonlinear p-Laplacian equation is studied for nonlinear functions with polynomial growth of arbitrary. Using Galerkin approximation and Legendre transform, by the energy estimate method,  the existence of solution is proved  for a general doubly nonlinear p-Laplacian equation.

    Oscillation of solutions to a class of even order neutral-damped partial differential equations with continuously distributed delays
    CAI Jiang-tao
    J4. 2011, 46(3):  94-98. 
    Abstract ( 676 )   PDF (320KB) ( 319 )   Save
    Related Articles | Metrics

    Oscillatory properties of solutions to a class of even order neutral partial differential equations with damped terms and continuously distributed delays are studied. Some criteria of sufficient conditions for the oscillation of all solutions of the equations are obtained under boundary condition by making use of Riccati transformation and introducing a class of new functions  Φ(t,s,l).

    The generalized inverses of the Almost Sharp quantum effect
    SHAO Chun-fang
    J4. 2011, 46(3):  99-101. 
    Abstract ( 735 )   PDF (279KB) ( 558 )   Save
    Related Articles | Metrics
    Remarks on sub-fractional Brownian motion
    SHEN Guang-jun 1,2, HE Kun 3, YAN Li-tan 3
    J4. 2011, 46(3):  102-108. 
    Abstract ( 772 )   PDF (327KB) ( 321 )   Save
    Related Articles | Metrics

    Let SH={SHt,t≥0} be a sub-fractional Brownian motion with index H∈(0,1). It is shown that the increment process generated by the sub-fractional Brownian motion (SHh+t-SHh,t≥0) converges to a fractional Brownian motion with Hurst index H in the sense of finite dimensional distributions, as h tends to infinity. Also,  the limit theorems associated with the subfractional Brownian noise are also studied.

    Jensen′s inequality for sub-linear expectations
    SONG Li1,2
    J4. 2011, 46(3):  109-111. 
    Abstract ( 703 )   PDF (256KB) ( 570 )   Save
    Related Articles | Metrics

    Under the framework of sub-linear expectations, it is proved that the Jensen′s inequality of sublinear expectations holds for the continuous convex function and the continuous non-decreasing concave function.

    A note on the solutions K+ and K-of reflected BSDEs with double obstacles
    ZHENG Shi-qiu1, LIU Yu-chun2, ZHENG Chun-hua3
    J4. 2011, 46(3):  112-115. 
    Abstract ( 729 )   PDF (293KB) ( 635 )   Save
    Related Articles | Metrics

    The strict comparison problem of reflected backward stochastic differential equations with double obstacles is discussed and some properties of the solutions K+ and K- of reflected BSDEs with double obstacles are given.

    The improved estimator of variance components in the banlanced nested error component model
    ZHAO Jing, WANG Lei
    J4. 2011, 46(3):  116-120. 
    Abstract ( 712 )   PDF (317KB) ( 387 )   Save
    Related Articles | Metrics

    For the balanced nested error component regression model which has three variance components, the Analysis of Variance (ANOVA)type estimators—WH estimators,WK estimators, and SA estimators are obtained by the methods Baltagi used. What is more,  the improved estimators are provided, especially aiming at the WK estimators of variance components of random effect and random error respectively, and it is proved that the improved estimators obtained are better than the estimators obtained by the methods Baltagi used under the mean-squared-error criterion.

    Design of finite-time normal observer for a linear singular time-delay system
    LU Li-hua, WU Bao-wei*
    J4. 2011, 46(3):  121-126. 
    Abstract ( 688 )   PDF (583KB) ( 313 )   Save
    Related Articles | Metrics

    Based on previous studies, a finite-time observer of the linear singular time-delay systems is designed. First, Lambert W function and its character were discussed. On this basis, the condition of judging timedelay system′s stability and the observer which converges to state asymptotically were given. Second, using eigenvalue assigning technology based on Lambert W function, an easy and convenient way of resolving finite-time normal observers′ coefficient matrix was proposed. Finally, Matlab was used to simulate a practical exam, and the result proved that the design proposed in this paper was effective and efficient, and it could be applied well in linear singular time-delay systems.